Draw type optical recording medium

The DRAW type optical recording medium which can record optical information by forming information pits in the recording layer by irradiation of an energy beam such as laser beam, and yet can reproduce the information immediately after writing without requiring any step of developing processing after writing of information. The optical recording medium includes a recording layer (3) for forming information pits through the occurrence of physical deformation by irradiation of an energy beam and a sensitizing layer (4) for augmenting the physical deformation in the recording layer (3) laminated on a support (2). By the presence of the sensitizing layer, recording sensitivity is improved and also stability of the medium with lapse of time becomes excellent. Further, due to the presence of the sensitizing layer, the optical recording medium can be a sealed structure and therefore the optical recording medium is lightweight and flexible, and can be made in various forms such as card, sheet, a flexible sheet, and the like.

TECHNICAL FIELD 
This invention relates to an optical recording medium which can record 
optical information by forming pits on a recording layer by irradiation of 
an energy beam such as a laser beam and, more particularly, the present 
invention relates to the so-called DRAW (direction-read-after-write) type 
which can "directly read after writing" without requiring the step of 
developing processing, etc. after writing of information. 
BACKGROUND ART 
In the prior art, as a high density optical recording medium, there have 
been known two methods, namely the method in which a metal, a semi-metal 
or an organic compound is melted or evaporated by a highly converged 
recording light such as a laser beam to form a concave portion or a pit 
portion, and the method in which discrimination pits are formed by a 
transfer between two thermodynamically semi-stable states such as 
crystalline and non-crystalline states. 
These optical recording methods provide optical recording materials and 
tracking patterns for following an optical beam on generally rigid glass 
discs or plastic discs, and the medium recorded according to this method 
has been generally known as a medium shaped in optical recording disc. 
Such medium shaped in optical recording disc, while having the advantages 
of high dimensional precision and high mechanical strength, has on the 
other hand problems that the driving device becomes greater in scale, and 
also the medium as well as the device are expensive for the reasons such 
that the weight and the thickness become greater. Accordingly, such medium 
has not yet been generally prevailed widely. For an optical recording 
medium capable of high density recording to be generally prevailed widely, 
in addition to the medium shaped in optical recording disc of the prior 
art, advent of an optical recording medium which is lightweight, compact 
and yet inexpensive such as a medium shaped in optical record flexible 
disc, a medium shaped in optical recording card, a medium shaped in 
optical recording tape, a medium shaped in optical recording sheet has 
been awaited. 
Of the two high density optical recording methods as described above, the 
first method must form a concave portion or a pit portion during 
recording. For this purpose, the substance must be taken away by melting 
or evaporation, whereby the mass transfer during recording becomes 
unavoidably great. Therefore, for making the recording sensitivity 
sufficiently large, it has been frequently practiced to make substance 
transfer readily occur by having the recording portion of the optical 
recording material exposed to the air. However, in this case, the optical 
recording material may be oxidized by the influence of the moisture in the 
air to cause deterioration, or foreign matter may be collided against the 
optical recording material, whereby there is a danger that an accident may 
occur such that the optical recording material may be mechanically 
destroyed. For this reason, there is employed a structure in which the 
optical recording material is sealed with a gap interposed therebetween. 
However, in a medium structure having such vacant space, both weight and 
thickness are increased, whereby it is difficult to give a diversity of 
shapes such as flexible disc, card, tape, sheet, etc. 
On the other hand, the second method, namely the method in which transfer 
between the thermodynamically semi-stable states is utilized, due to small 
substance transfer during recording, the optical recording material is not 
required to be exposed to the air, but sealing is possible without 
provision of a gap. Therefore, according to the recording method by such 
transfer, it can correspond to a diversity of shapes of medium. In the 
prior art, as the material to be used for such transfer, 
crystalline--non-crystalline phase transfer materials such as TeO.sub.x, 
As-Te-Ge have been known. However, the phase transfer materials of the 
prior art tend to be remarkably unstabilized with lapse of time, and also 
the optical characteristic change amount between crystal and non-crystal 
is smaller as compared with the above pit portion formation, whereby it is 
not necessarily satisfactory with respect to precision of recording and 
reproduction. 
DISCLOSURE OF THE INVENTION 
The present invention has been accomplished in view of the problems 
accompanied with the prior art, and aims at the following points. 
(a) To provide an optical recording medium having stable recording 
characteristics with lapse of time. 
(b) To provide an optical recording medium which can effect recording and 
reproduction of high sensitivity and can be made to have a structure of 
essentially sealed type without requiring the optical recording material 
layer to be exposed to the external air or to provide a gap in the 
material layer. 
(c) To provide an optical recording medium of light weight and low cost 
which can be applied for medium of various forms such as flexible disc, 
card, tape, sheet, etc. 
In order to accomplish the objects as mentioned above, the DRAW type 
optical recording medium according to the present invention comprises (a) 
a recording medium for forming information pits through occurrence of 
physical deformation by irradiation of an energy beam and (b) a 
sensitizing layer for augmenting thermochemically the physical deformation 
in said recording layer provided on a support. 
Thus, in the present invention, since a sensitizing layer is formed by 
lamination on the recording layer, the recording sensitivity of 
information pits onto the recording layer is remarkably improved by the 
sensitizing layer. Further, by the sensitizing layer, the substance 
transfer during formation of pits onto the recording layer can be rapidly 
absorbed, and therefore it is not necessary to provide a space for 
substance transfer in the medium as in the prior art, whereby the medium 
structure can be made the essentially sealed type structure.

BEST MODES FOR PRACTICING THE INVENTION 
As shown in the sectional view in FIG. 1, the optical recording material 1 
according to one embodiment of the present invention has a structure 
comprising a recording layer 3 and a sensitizing layer 4 laminated in this 
order on the surface (the lower side in this Figure) of the support 2. In 
such embodiment, as shown in the Figure, recording and reading of 
information are effected from the side of the support (light-transmissive) 
2. Accordingly, although not shown, the sensitizing layer and the 
recording layer 3 may be also laminated in this order on the support 2, 
and in this case, recording and reading of information are effected from 
the recording layer side. 
Further, in the optical recording material of the present invention, a 
protective layer (not shown) comprising a synthetic resin, etc. may be 
also formed on the surface of the sensitizing layer 4 which becomes the 
outermost layer. 
Also, in the optical recording material of the present invention, as the 
embodiment shown in FIG. 2, another substrate 6 can be further laminated 
and integrated through an adhesive layer 5 on the surface of the 
sensitizing layer 4. 
In the following, the respective constituent elements are to be described. 
SUPPORT 
The support 2 is provided for supporting an optical recording material, and 
can be constituted of all the materials known in the art. Further, the 
support 2 may have another recording means formed thereon, if desired. 
For the support 2, the material can be selected by determining the strength 
and the extent of flexibility in conformity with the use. For example, as 
the plastic, polycarbonate, polyester terephthalate, polyester resin, 
epoxy resin, acrylic resin, polyvinyl chloride resin, or polystyrene resin 
can be used, but otherwise ceramics such as glass can be also used. When 
the support 2 has a constitution as shown in FIG. 1, it is required to be 
transparent (including light-transmissiveness) for permitting the beam for 
recording and reproduction to transmit therethrough. These materials for 
support may be also previously added with appropriate additives depending 
on the use. 
RECORDING LAYER 
The recording layer 3 can be formed from a thin film of a metal having high 
light reflectance. As the metal, there may be included chromium, titanium, 
iron, cobalt, nickel, copper, silver, gold, germanium, aluminium, 
magnesium, antimony, tellurium, lead, palladium, cadmium, bismuth, tin, 
selenium, indium, gallium or the like, and these metals can be used either 
singly or as an alloy comprising a combination of two or more kinds. 
Further, oxides of these metals can be also similarly used. The thickness 
of the recording layer comprising a thin film of these metals or alloys 
may be 100 to 1000 .ANG., more preferably 200 to 500 .ANG.. 
As a preferable example of the recording layer 3 in the present invention, 
a tellurium thin film as a simple substance metal may be used. Tellurium 
has a small thermal conductivity and an adequate degree of light 
absorptivity. In this case, the tellurium thin film may be either 
crystalline or amorphous. When the recording layer is formed of amorphous 
tellurium, it is preferable to previously crystallize the recording layer 
during recording. The recording layer in this case may have a thickness 
generally of 50 to 2000 .ANG., preferably 200 to 800 .ANG.. Tellurium as a 
simple substance metal is susceptible to oxidation and inferior in 
humidity resistance, and also due to relatively higher melting point, the 
writing sensitivity is low and therefore it is generally believed to be 
undesirably used as the reflective layer for optical recording medium. 
However, on the other hand, the present inventors were interested in 
readiness of film preparation when using tellurium as the reflective layer 
and also the excellent characteristics possessed by the tellurium simple 
substance, and it is possible to obtain an optical recording medium 
excellent in stability of the characteristics with lapse of time by 
compensating for the drawbacks of tellurium as mentioned above while 
utilizing positively such good characteristics of the tellurium simple 
substance. 
Also, in the present invention, the recording layer may also comprise a 
laminate of two layers, namely a first recording layer comprising a 
light-transmitting portion and a light-intercepting portion, and a second 
recording layer comprising a light reflective metal thin film. The first 
recording layer in this case can be formed by, for example, subjecting a 
light-sensitive material of which the unexposed portion becomes 
light-transmissive and the exposed portion becomes the light-intercepting 
portion to pattern exposure, followed by development. In some cases, a 
light-sensitive material of which the unexposed portion becomes 
light-transmissive may be subjected to pattern exposure and then developed 
to form the first recording layer. On the other hand, as the second 
recording layer, the same material as the material for the recording layer 
as mentioned above may be suitably used. 
The light-sensitive material to be used for the above first recording layer 
may be constituted of, for example, (a) a transparent resin as the binder, 
(b) a photodecomposable developing inhibitor having a diazo group or an 
azide group and (c) a metal complex compound or a metal compound which 
becomes the metal nucleus developed by reduction. In such light-sensitive 
material, the photodecomposable developing inhibitor exists in an amount 
up to 100 parts by weight, preferably 20 to 50 parts by weight, and the 
metal complex compound or the metal compound which becomes the metal 
nucleus developed by reduction in an amount of 0.1 to 1000 parts by 
weight, preferably 1 to 10 parts by weight based on 100 parts by weight of 
the transparent resin as the binder. The developing inhibitor, the metal 
complex compound or the metal compound are dissolved or dispersed in the 
transparent resin as the binder, but preferably dissolved therein. 
The image information brought about from the light-transmitting portion and 
the light-intercepting portion in the first recording layer as described 
above can function as the information itself or as the tracking and 
preformat during reading of the information. 
Further, in the present invention, the recording layer can be constituted 
of an oxide of tellurium represented by TeO.sub.x and the sensitizing 
layer of an oxide of tellurium represented by TeO.sub.y (with proviso that 
x and y are positive real number, having the relationship of x&lt;y), and 
such constitution will be described below. 
SENSITIZING LAYER 
The sensitizing layer 4 is formed by lamination so as to be in close 
contact with the recording layer 3. The sensitizing layer will promote 
thermochemically the physical deformation in the recording layer when an 
information pit is formed in the recording layer through occurrence of 
physical deformation by irradiation of an energy beam, consequently 
contributing to improvement of the information recording sensitivity. 
Further, by the sensitizing layer, substance transfer during pit formation 
onto the recording layer is rapidly absorbed or promoted, whereby it is 
not necessary to provide specifically a space for substance transfer in 
the recording medium as in the prior art. Accordingly, in the present 
invention, by providing such sensitizing layer, the structure of the 
recording medium can be made a structure of the sealed type. In the 
following, the respective embodiments are to be described. 
(1) Thermoplastic Resin 
When an information pit is recorded onto an optical recording medium, the 
recording layer is melted by absorption of the irradiated energy beam onto 
the recording layer, whereby the recorded portion (lower reflective 
portion relative to the portion not irradiated) is formed, and in this 
case it is difficult to form a recorded portion which is uniform and has 
desirable pit shape by only melting the recording layer. 
In the first embodiment of the present invention, by use of a thermoplastic 
resin as the material for the sensitizing layer, excellent effect can be 
exhibited in improvement of recording sensitivity and stability with lapse 
of time. The reason why such effect can be exhibited is not necessarily 
clear, but it may be considered that the thermoplastic resin as the 
sensitizing layer is softened by the heat generated by the light 
irradiated on the recording layer, thereby absorbing (diffusing) 
effectively the material for the recording layer which is melted or 
evaporated, and yet this is accompanied with thermal deformation of the 
sensitizing layer, whereby such thermal deformation will contribute 
synergetically to uniformization and ready formability of the pit shape. 
As the material for exhibiting such effect, various thermoplastic resins 
are available. Specific examples may include vinyl resins of homopolymers 
or copolymers of vinyl chloride, vinyl acetate, vinylidene chloride, 
petroleum resins such as polyethylene, polypropylene, polybutene, etc., 
acetal resins such as formal, butyral, etc., acrylic resins such as acryl, 
methacryl, polyacrylonitrile, etc., styrol resins such as polystyrol, ABS, 
AS, polyamide resins, etc. 
Also, in the present invention, the above effect can be further promoted by 
addition of a light absorbing agent in the sensitizing layer. 
As the light absorbing agent to be added in the thermoplastic resin, dyes, 
pigments and metal powder generally employed can be used. Specifically, 
there may be preferably used polymethine type dyes, pyrylium type, 
thiopyrylium type, squalilium type, croconium type, phthalocyanine type, 
dithiol metal complex type, naphthoquinone, anthraquinone type, 
triphenylmethane type, aminium type, diinmonium type, methylcaptonaphthol 
metal complex type dyes, or metal powder such as Te, Bi, Se, Ge, Zn, etc. 
The thickness of such sensitizing layer may be preferably 1 to 100 .mu.m. 
(2) Silicon Compound Thin Film 
In the second embodiment, by the use of a silicon compound thin film as the 
sensitizing layer, an optical recording medium having excellent recording 
sensitivity and yet having improved stability can be obtained. 
As such silicon compound, there are silicon dioxide or organic silicon 
compounds containing silicon as the constituent element, and these 
compounds can be formed according to the method such as the sputtering 
method, the plasma polymerization method, etc. 
Among them, in this embodiment, a silicon compound thin film formed by the 
plasma polymerization method is particularly excellent as the sensitizing 
layer. 
Since the plasma polymerization is a dry process using no solvent, there is 
no deterioration or corrosion of the coated surface with the solvent, and 
therefore there is generated no film surface badness of the thin film 
formed on account of such causes. Accordingly, the layer provided 
according to the plasma polymerization method by use of a silicon type 
compound is a dense film without pinhole and yet has excellent heat 
insulating property. Thus, by forming a thin film having excellent 
insulating property in close contact with the recording layer, diffusion 
of the heat generated in the recording layer during recording can be 
prevented to promote melting and evaporation of the pit forming portion of 
the recording layer, whereby recording sensitivity can be remarkably 
improved. Also, since diffusion prevention of the heat can be effectively 
done, the influence of the heat on other layers can be made smaller to 
prevent denaturation of the constituent material, thereby improving also 
stability with lapse of time. 
The silicon compound thin film constituting the sensitizing layer is formed 
according to the plasma polymerization method in a conventional manner, 
and as the silicon compound, silane type compounds, siloxane type 
compounds, functional group containing silicon compounds can be used. 
Specific examples may include silane compounds such as silane, disilane, 
monomethylsilane, dimethylsilane, tetramethylsilane, diethylsilane, 
tetramethyldisilane, hexamethylsilane, cyclohexyldimethylsilane, 
cyclotrimethylenedimethylsilane, dimethyldimethoxysilane, etc.; siloxane 
compounds such as hexamethyldisiloxane, tetramethyldisiloxane, 
pentamethyldisiloxane, cyclic dimethylsiloxane, etc.; further functional 
group containing silicon compounds such as vinyl trichlorosilane, vinyl 
triethoxysilane, vinyl tris(o-methoxyethoxy)silane, 
.gamma.-glycidoxypropyltrimethoxysilane, 
.gamma.-methacryloxypropyltrimethoxysilane, 
.gamma.-mercaptopropyltrimethoxysilane, 
.gamma.-aminopropyltriethoxysilane, .gamma.-chloropropyltrimethoxysilane, 
etc. 
Also, in the above method, since the sensitizing layer is formed by the 
plasma polymerization method, namely by use of a dry process without use 
of a solvent, there is no deterioration or corrosion of the coated surface 
with a solvent, to generate no film surface badness of the thin film 
formed on account of such causes, to give excellent recording 
characteristics. 
(3) Fluoride or Carbide Thin Film 
In this embodiment, by use of a metal or semi-metal fluoride or carbide as 
the sensitizing layer, an optical recording medium having excellent 
recording sensitivity and yet having improved stability can be obtained. A 
thin film comprising a metal or semi-metal fluoride or carbide is dense 
with pinhole being difficultly formed, and yet has excellent heat 
insulating property. 
Thus, by forming a thin film having excellent insulating property in close 
contact with the recording layer, diffusion of the heat generated in the 
recording layer during recording can be prevented to promote melting and 
evaporation of the pit forming portion in the recording layer, whereby 
recording sensitivity can be remarkably improved. Also, since diffusion 
prevention of heat can be effectively done, the influence of the heat on 
other layers can be made smaller, whereby denaturation of the constituent 
material can be prevented to improve also stability with lapse of time. 
As such sensitizing layer, specifically, fluorides such as MgF.sub.2, 
PbF.sub.2, NbF.sub.3, ZnF.sub.2, carbides such as B.sub.4 C, Mo.sub.2 C, 
NbC, SiC, TaC, TiC, W.sub.2 C, ZrC may be preferably used. 
The thickness of such sensitizing layer may be preferably 100 to 10,000 
.ANG., more preferably 300 to 1,000 .ANG.. 
(4) Hot Melt Type Adhesive 
In this embodiment, by use of a hot melt type adhesive layer, excellent 
effect can be exhibited in improvement of recording sensitivity and 
stability with lapse of time. The reason why such effect can be exhibited 
is not necessarily clear, but similarly as in the above first embodiment, 
it may be considered that the sensitizing layer 4 itself is softened to be 
lowered in viscosity by the heat generated by the light irradiated on the 
recording layer 3, thereby absorbing (diffusing) rapidly and effectively 
the melted or evaporated light reflective layer material, and yet this is 
accompanied with thermal deformation of the sensitizing layer 4, whereby 
such thermal deformation will contribute synergetically to uniformization 
and ready formability of pit shape. 
As the material for exhibiting such effect, hot melt type adhesives 
generally employed are available. Specific examples of the base polymer 
comprise a composition of one or two or more kinds of ethylene and 
ethylene copolymers such as polyethylene, ethylene-vinyl acetate copolymer 
(EVA), EVA modified polymer, ethylene-acrylate copolymer, ionomer resins, 
etc., polyester resins, polyamide resins, nylon resins, polypropylene 
resins, cellulose derivative type resins, polyvinyl type resins, 
polyurethane type resins, ethylene-propylene type resins, styrene-butylene 
block copolymer type resins, styrene-isoprene copolymer type resins, etc., 
and examples of tackifying resins comprise a composition of one or two or 
more kinds of rosins and rosin derivatives such as hydrogenated rosin, 
esterified rosin, polymerized rosin, etc., terpene type resins such as 
terpene resin, terpene-phenol copolymer, etc., aliphatic petroleum resins, 
aromatic petroleum resins, hydrogenated petroleum resins, cyclopentadiene 
type petroleum resins, styrene type resins, isoprene type resins, etc., 
which may be optionally added with various additives such as pigments, 
plasticizers, antioxidants, etc. 
The thickness of the sensitizing layer as described above may be preferably 
1 to 100 .mu.m. 
In the above embodiment, the hot melt type adhesive has also the function 
as an adhesive together with the function as the sensitizing layer at the 
same time. Accordingly, by use of such material as the sensitizing layer, 
improved effect of adhesiveness, closeness between the respective layers 
(namely between the sensitizing layer and the recording layer, or between 
the sensitizing layer and other layers) can be obtained along with the 
sensitizing effect. Also, in the above embodiment, since such adhesive 
effect can be obtained, when the sensitizing layer and another layer are 
laminated, it is not necessary to use separately an adhesive, thus 
contributing to simplification of the medium structure, thinner layer 
formation as well as simplification of the preparation steps. 
TeO.sub.x /TeO.sub.y 
In another preferred embodiment of the present invention, both the 
recording layer and the sensitizing layer can be constituted of oxides of 
tellurium. 
According to the knowledge of the present inventors, by constituting the 
recording layer of a thin film of a tellurium oxide, and further 
laminating a sensitizing layer comprising a similar tellurium oxide thin 
film on the surface of the recording layer, and constituting the recording 
layer side with a weak oxide with relatively smaller degree of oxidation 
and also constituting the sensitizing layer side with a strong oxide with 
greater degree of oxidation than the above recording layer, both of 
sensitivity and weathering resistance (stability) were found to be 
improved. More specifically, a weak oxide thin film of tellurium has a 
sensitivity equal to the simple substance Te as the recording layer and 
yet has the excellent stability and weathering resistance, and further 
improved in weathering resistance by laminating a sensitizing layer 
comprising strong oxide thin film of Te on the recording layer, and even 
when a recording medium may be formed by bonding this laminate onto 
another substrate, there occurs no lowering in sensitivity and variance in 
recording pit shape. 
Thus, the optical recording medium in this embodiment comprises a recording 
layer comprising an oxide of tellurium represented by the formula: 
TeO.sub.x (x is a positive real number) and a sensitizing layer comprising 
an oxide of tellurium represented by the formula: TeO.sub.y (y is a 
positive real number) laminated on a support, having the relationship of 
x&lt;y in the above formula. 
In the above formula, x may be generally preferred to be within the range 
of 0&lt;x.ltoreq.1.5. In this case, if x exceeds 1.5, reflectance and 
absorbance of light will be lowered to make information recording with 
laser impossible. 
On the other hand, y in the formula may be preferably in the range of 
0.5.ltoreq.y.ltoreq.2, and the above x and y have the relationship of x&lt;y. 
In this case, if y is less than 0.5, the oxide becomes the state 
approximate to metallic Te to give no sensitizing effect, and may 
sometimes result in lowering in sensitivity in an extreme case 
undesirably. 
Thus, the Te oxide can assume continuously various states from the state 
approximate to metallic Te having metallic luster to the state approximate 
to TeO.sub.2 transparent (light-transmissive) to visible light 
corresponding to its oxidation state. Accordingly, when the Te oxide is 
viewed as the optical recording material, it can be broadly classified 
into the weakly oxidized state which has metallic luster, reflects 
sufficiently the recording light and has excellent energy absorption 
characteristic (namely recording sensitivity is excellent to form readily 
pit), and the strongly oxidized state which is excellent in light 
transmissivity and little in reflection and absorption of recording light 
(namely having no recording characteristic). 
On the other hand, when the Te oxide is viewed in aspect of stability, it 
may be considered that stability is more excellent as the degree of 
oxidation is higher to be more approximate to TeO.sub.2, but according to 
the knowledge of the present inventors, sufficiently good stability can be 
obtained practically if x in the oxide TeO.sub.x is in the range of 0.3 or 
more. In the weakly oxidized state of such extent, an excellent effect can 
be obtained also in the recording sensitivity, whereby overall excellent 
characteristics as the recording layer can be exhibited. 
The thickness of the above recording layer 3 may be preferably 100 to 1500 
.ANG., more preferably 300 to 700 .ANG.. If the thickness of the recording 
layer is less than 100 .ANG., the light reflectance is inappropriately too 
small, while if it is over 1500 .ANG., sensitivity and recorded shape will 
be worsened. 
In contrast, the thickness of the sensitizing layer 4 may be preferably in 
the range of 50 to 5000 .ANG., more preferably 200 to 1000 .ANG.. If the 
sensitizing layer is less than 50 .ANG., it is too thin to not give a good 
sensitizing effect, while a thickness over 5000 .ANG. is too thick, 
whereby to the contrary cracks are liable to be formed undesirably. 
Meanwhile, also in the above embodiment, the sensitizing layer improves 
recording sensitivity and reproducing sensitivity onto the recording layer 
similarly as other embodiments as described above. That is, in the optical 
recording medium of the above embodiment, during recording of optical 
information, information recording is effected by forming pits on the 
recording layer with a laser beam, etc., while during reproduction of 
recording information, reading of recording information is effected by 
detecting the difference in light reflectance at the pit formed portion. 
Accordingly, the sensitizing layer contributes to improvement of 
sensitivity by making the difference in reflectance from the recording 
layer greater, and also has the following effects in addition thereto. 
(a) It protects the recording layer to improve weathering resistance and 
stability of the optical recording medium. 
(b) It has an extremely excellent effect in making regular the shapes of 
the recorded pits. That is, no recorded residual portion will be formed in 
the inner portions or the peripheral portions of the recorded pit, whereby 
recorded pits with smooth peripheral portions can be formed. 
(c) For example, when the above optical recording medium is integrated by 
adhesion onto another, for example, substrate for card for the purpose of 
making a card, in the absence of such sensitizing layer, sensitivity will 
be remarkably lowered to give rise to variance in size of the recorded 
shape. Therefore, presence of the sensitizing layer is extremely effective 
in cancelling such problems, and the optical recording medium with a 
constitution as described above is particularly suitable when forming the 
so-called sealed type optical card. 
Also, the optical recording medium of the above embodiment comprises the 
recording layer and the sensitizing layer which are constituted of the 
materials of the same compositional components only with different 
compositional ratios (namely the ratio of Te to oxygen), and therefore is 
very excellent in preventing undesirable reactions at the interface 
between both the layers, as compared with the case when employing the 
materials mutually different in the constituent components themselves. 
More specifically, generation of strain or stress based on physical, 
chemical interactions such as migration of the constituent elements at the 
interface between both the layers, or the difference in stress at the 
interface can be reduced as small as possible, and therefore an optical 
recording medium which is more stable physically, chemically and 
mechanically can be obtained. In the above embodiment, the above recording 
layer and the sensitizing layer may be also formed such that the 
compositional ratio of both the layers is under the state continuously 
varied. In other words, in the optical recording medium of the above 
embodiment, the respective Te/O ratios of the Te oxide constituting the 
recording layer and the Te oxide constituting the sensitizing layer may be 
varied continuously at the interface between both the layers, and it is 
only sufficient that the layers comprising at least the two kinds of the 
weak oxide ad the strong oxide substantially as described above may be 
formed. 
(1) Thin Film Forming Method A 
The Te oxide thin film constituting the recording layer and the sensitizing 
layer of the above embodiment can be obtained readily according to the 
reactive sputtering method. More specifically, by use of simple substance 
Te as the target, by effecting sputtering while discharging a gas mixture 
of oxygen and an inert gas, a thin film with a desired composition ratio 
can be formed. Such reactive sputtering method can be performed according 
to the method known in the art, and details thereof are disclosed in, for 
example, "Sputtering Phenomenon" (by Akira Kinbara, Tokyo Daigaku 
Shuppankai, 1984, pp. 120-132). 
Formation of Te oxide thin film according to the reactive sputtering method 
as described above can be performed by means of a conventional sputtering 
device, but the sputtering may be performed by making the atmosphere 
within the device a gas mixture of argon and oxygen, and further within 
the device, there may be also applied such modification as provision of a 
jetting outlet of oxygen for the purpose of improving the reaction 
efficiency of oxygen. 
The relationship between the mixing ratio of the inert gas to oxygen gas 
and the oxygen concentration in the thin film obtained is the qualitative 
relationship such that the oxygen amount in the thin film is increased as 
the content of the oxygen in the gas mixture is increased, and its 
quantitative relationship depends on the structure of the sputtering 
device employed, the discharging speed, the pressure during sputtering, 
the method of gas introduction, etc. and therefore the general 
relationship is different depending on the respective devices. However, 
calling attention on one device, if the profile of the running conditions 
is set, and then the oxygen concentration in the thin film is determined 
depending on the mixing ratio of the gases, and therefore reproducibility 
of preparation of thin film is good. Accordingly, within the same device, 
the recording layer and the sensitizing layer can be prepared 
substantially continuously by varying the gas mixing ratio. 
The advantages for forming the thin film according to the reactive 
sputtering method are as described below. 
(i) Since the oxidation state of Te can be controlled to a desired state by 
the mixing ratio of an inert gas and oxygen, it becomes possible to form 
both of the recording layer and the sensitizing layer by using only one 
kind of target. Generally speaking, a target comprising an alloy or a 
compound can be produced with difficulty as compared with a simple 
substance target and is more expensive. 
(ii) Since the flow rates, mixing ratio of the gases introduced can be 
controlled easily and extremely precisely by use of a device such as mass 
flow controller, excellent reproducibility in preparation of thin film can 
be obtained. In contrast, when a thin film of an alloy or compound is 
prepared according to the vapor deposition method of the prior art, etc., 
it is generally difficult to prepare a thin film with good state of 
reproducibility of the composition ratio. 
(iii) The deposition speed of the film is great to give excellent 
productivity. When a Te oxide is used as a target, the deposition speed 
for the target is low to give inferior productivity. In contrast, 
according to the above method, since a simple substance Te is used as a 
target, it becomes possible to effect deposition at high speed and yet at 
low temperature and within a short time, whereby improvement of both 
productivity and quality can be effected. 
(iv) A conventional sputtering device can be used as such. 
(2) Thin Film Forming Method B 
The recording layer and the sensitizing layer of the above embodiment can 
be also prepared by irradiating ion beam comprising oxygen containing gas 
onto said support simultaneously with evaporation of Te toward the support 
according to the vacuum vapor deposition method. 
The method and the device for preparing a two-component system thin film as 
described above are disclosed in Japanese Patent Application No. 
53385/1986 already proposed by the present inventors, and the method 
disclosed in this specification can be employed by varying the conditions. 
The film preparation conditions in the case of applying the above method 
for the present invention are as follows. 
(a) Conditions common to film preparation of both the recording layer and 
the sensitizing layer: 
Preliminary evacuation: 10.sup.-5 Torr 
Introduced gases: oxygen and inert gas 
Film forming speed of Te: 1-500 .ANG./sec. 
Vacuum degree: 3.times.10.sup.-5 -1.times.10.sup.-3 Torr (outside of this 
range, actuation of ion gun becomes unstable) 
(b) Formation of recording layer: 
Operational conditions of ion gun: 
Voltage applied: 50-1000 V 
In this case, at less than 50 V, the ion current can be controlled with 
difficulty, while in excess of 1000 V, the sputtering effect is increased 
to make film preparation difficult. 
Ion current density: 10-300 .mu.A/cm.sup.2 
In this case, at less than 10 .mu.A/cm.sup.2, oxidation is insufficient to 
lower stability with lapse of time, while in excess of 300 .mu.A/cm.sup.2, 
oxygen becomes excessive to bring about lowering in recording sensitivity. 
Film thickness: 100-1500 .ANG. 
At less than 100 .ANG., reflectance is insufficient, while in excess of 
1500 .ANG., contrariwise recording sensitivity is lowered. 
(c) Formation of sensitizing layer: 
Operational conditions of ion gun: 
Acceleration voltage: 50-1000 V 
In this case, at less than 50 V, the ion current can be controlled with 
difficulty, while in excess of 1000 V, the sputtering effect is increased 
to make film preparation difficult. 
Ion current density: 200-1000 .mu.A/cm.sup.2 
In this case, at less than 200 .mu.A/cm.sup.2, oxidation is insufficient to 
lower recording sensitivity, while in excess of 1000 .mu.A/cm.sup.2, the 
support is subject to heat loss by the ion current undesirably. 
Film thickness: 50-5000 .ANG. 
At less than 50 .ANG., recording sensitivity is lowered, while in excess of 
5000 .ANG., contrariwise the problem of peel-off of thin film will be 
caused. 
The method of using the ion beam irradiation and the vapor deposition in 
combination as described above has the following advantages. 
(a) The composition of the desired thin film can be controlled easily. That 
is, only by controlling the acceleration voltage and the ion current of 
the ion gun to desired state, a thin film with a desired composition can 
be obtained, and therefore controllability is extremely excellent. 
(b) Since the reactivity during formation of an oxide is high, thin film 
formation can be effected under a relatively lower temperature 
(100.degree. C. or less), a good thin film can be formed also when the 
transparent support comprises a material relatively weak in resistance to 
heat such as plastic, etc. 
(c) Since film formation can be effected under high vacuum, entrainment of 
an impurity into the thin film can be prevented as far as possible, 
whereby an optical recording medium with excellent quality can be 
prepared. 
SPECIFIC EXAMPLE OF LAYER CONSTITUTION 
As shown in FIG. 2, in the DRAW type optical recording medium 1 of the 
present invention, a substrate 6 may be also formed through an adhesive 
layer 5 on the sensitizing layer 4 side. The substrate 6 can be selected 
from any desired material depending on the use, the final desired product. 
Further, the substrate 6 (or the substrate 2) may have also another 
recording means such as magnetic stripe, hologram, imprint, photograph, 
bar code, printing in general formed thereon. 
The adhesive layer 5 integrates by bonding the substrate 6 to the 
sensitizing layer 4, and the adhesive is selected in view of the materials 
above and below the adhesive surface. Specifically, an adhesive which is 
of the type curable under heating or at a temperature of 50.degree. C. or 
lower and can give sufficiently good adhesive force between the upper and 
lower materials can be preferably used. 
The embodiment shown in FIG. 3 is an example when the transparent support 2 
is constituted of an unevenness forming layer 2a for tracking, a 
transparent plate 2b and a surface protective layer 2c. In this case, the 
surface protective layer 2c may be formed or not. Also, a primer layer 
(not shown) may be also provided between these respective layers. 
The unevenness forming layer for tracking functions as the guide groove for 
tracking during recording and reading of information, and its shape may be 
one applied with fine unevenness or a matte working for scattering light 
along the guide groove as shown in FIG. 4. 
The surface protective layer 2c is provided at the outermost layer, has 
high hardness, comprises preferably a material with smaller refractive 
index of light than the transparent plate 2c, and by selecting such a 
material, the recording and producing sensitivity can be further enhanced 
by the action of preventing undesirable reflection of the laser beam 
during recording and reproduction. Specifically, cured resins obtained by 
curing of silicon type, acrylic type, melamine type, polyurethane type or 
epoxy type resins can be used. 
FIG. 5 and FIG. 6 are each an example when an unevenness forming layer for 
tracking is provided integrally in the transparent support 2 in FIG. 3 and 
FIG. 4, respectively. 
In the embodiment of the optical recording medium shown in FIG. 3-FIG. 6 as 
described above, since the recording layer and the sensitizing layer are 
built in and sealed internally of the laminate, and the respective layers 
have the constitution closely contacted with each other, and therefore 
have excellent weathering resistance to external environment to be 
advantageous in both of improvement of stability with lapse of time and 
improvement of sensitivity. 
Next, referring to FIG. 7, a specific example of the method for preparing 
of the close adhesion type and the sealed type according to the present 
invention is to be described. 
First, a transparent sheet 21 is prepared, one surface of the transparent 
sheet is coated with a coating solution of a curable resin according to 
the known method, followed by drying and curing, or a metal oxide is 
formed as the thin film according to the sputtering method or a surface 
protective layer 22 is formed according to the plasma polymerization 
method. 
Next, the transparent sheet having the surface protective layer 22 formed 
thereon is coated on the surface where there is no surface protective 
layer 22 with a coating solution of a material of primer, followed by 
drying to form a primer layer 23. As described below, the primer layer 23 
can be omitted. 
On the primer layer 23 on the surface opposite to the surface protective 
layer 22 of the transparent sheet 21, or on the surface of the transparent 
sheet 21, a coating solution of a curable type resin is applied and cured 
to form a tracking forming layer 24. 
During formation of a tracking forming layer 24, a groove for tracking 25 
can be also formed, and after coating of the coating solution of the 
curable resin, with a matrix for imparting a predetermined shape of the 
guide groove 25 for tracking is closely contacted thereon, and under such 
state the resin in the coating solution may be cured. 
On the tracking forming layer 24, a thin film of a metal or oxide or alloy 
thereof is formed according to the thin film forming method as described 
above such as vacuum vapor deposition or sputtering to provide a recording 
layer 26. In the case of other than a metal or an oxide or alloy thereof, 
the recording layer 26 is formed acccording to a suitable thin film 
forming method or coating method. 
The sensitizing layer 27 to be formed on the recording layer 26 can be 
formed according to the vacuum vapor deposition method, the sputtering 
method, etc. in the case of a metal oxide, nitride, sulfide; can be formed 
according to the spin coating method, the gravure coating method in the 
case of a thermoplastic resin or a hot melt type adhesive; and can be 
prepared according to the sputtering method or the plasma polymerization 
method in the case of a silicon compound thin film, a hydrocarbon compound 
thin film. 
The transparent sheet 21 has the respective layers formed on both surfaces 
thereof, and either one of the surfaces may be applied with working first, 
provided that the mutual relationship of the respective layers is not 
changed. 
Separately from the above working for the transparent sheet 21, a substrate 
28 is prepared. The substrate 28 is applied with reinforcement or has 
another recording means other than the optical recording layer formed 
thereon as described above. 
The transparent sheet 21 finished of working, and the substrate 28 are 
combined after coating an adhesive 29 on either one or both of the surface 
of the substrate 28 and the surface of the sensitizing layer 27 of the 
lower surface of the transparent sheet 21, and after taking optionally an 
open time, and closely adhered according to the pressing method or 
according to the hot pressing method by use of a hot plate to give an 
optical recording medium. 
In the present invention, as shown in FIG. 8, during formation of the 
transparent sheet 21, a guide groove 25 for tracking can be molded as 
integrated therewith, whereby a medium constitution further simplified can 
be obtained. In this case, as the method for preparation of the 
transparent sheet, injection molding, press molding method by use of a 
resin such as acryl, polycarbonate, etc. can be employed. 
In the following, the materials, etc. for the respective layers in the 
above layer constitution are described in more detail. 
The tracking forming layer 24 is provided for regulating the position of 
the optical information during recording and reproduction on the light 
reflective layer, and should preferably have humidity resistance and 
weathering resistance for protection of the recording layer 26, and may be 
preferably a material having insulating property for improvement of 
sensitivity. Further, for formation of a guide groove for tracking, it 
should preferably have a necessary form imparting property. As the 
material satisfying these points, curable resins, particularly ionized 
radiation curable resins are desirable as one capable of avoiding the 
influence of heat during curing. 
Specifically, prepolymers or oligomers having ethylenically unsaturated 
bonds in the molecule as mentioned below, and the monomers optionally 
added with known sensitizers may be applied by coating, and cured by 
irradiation of ionized radiation such as UV-ray, electron beam or 
.gamma.-ray to form a tracking forming layer which functions as both the 
protective and sensitizing layers. 
1) Prepolymers or oligomers, and monomers having ethylenically unsaturated 
bonds in the molecule such as polyester (meth)acrylate, epoxy 
(meth)acrylate, urethane (meth)acrylate, polyether (meth)acrylate, polyol 
(meth)acrylate, melamine (meth)acrylate. 
2) Monomers having ethylenically unsaturated bonds in the molecule, 
including (meth)acrylic acid esters such as methyl (meth)acrylate, ethyl 
(meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl 
(meth)acrylate, methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, 
methoxybutyl (meth)acrylate, ethoxybutyl (meth)acrylate, butoxyethyl 
(meth)acrylate, lauryl (meth)acrylate, phenyl (meth)acrylate, etc.; 
unsaturated carboxylic acid amides such as (meth)acrylic acid amide; 
substituted amino alcohol esters of unsaturated carboxylic acids such as 
2-(N,N-dimethylamino)ethyl (meth)acrylate, 2-(N,N-dimethylamino)methyl 
(meth)acrylate, 2-(N,N-diethylamino)propyl (meth)acrylate, etc.; and 
otherwise ethylene glycol di(meth)acrylate, propylene glycol 
di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol 
diacrylate, diethylene glycol di(meth)acrylate, triethylene glycol 
di(meth)acrylate, dipropylene glycol di(meth)acrylate, trimethylolpropane 
tri(meth)acrylate, etc. 
As the sensitizer suitable for the prepolymer or the oligomer, and the 
monomer having unsaturated bonds to be used for such tracking forming 
layer which functions as both the protective and sensitizing layers, 
specific examples may include benzophenone type and benzoin ether type 
sensitizers. 
The tracking forming layer 24 may have a thickness of 3 to 20 .mu.m, more 
preferably 5 to 7 .mu.m. 
The primer forming layer 23 is provided directly for the sense to improve 
the adhesion strength between the tracking forming layer 24 and the upper 
layer transparent sheet 7, but it is not necessarily required when 
sufficient adhesion strength is obtained between the tracking forming 
layer 24 and the upper layer transparent sheet 7. As the material 
constituting the primer layer 23, a polymer of vinyl chloride or vinyl 
acetate resin or copolymers of these may be employed. 
The transparent sheet 21 protects the optical recording material, and plays 
a role as a substrate in preparing the optical recording material. Since 
optical information is recorded or reproduced by irradiating a laser beam 
from the transparent sheet 21 side, a material having sufficient 
transmittance relatively to a laser beam, particularly to the wavelength 
of the laser beam of a semiconductor laser which is small in scale and 
high in output is suitable as the transparent sheet 21. Specific examples 
may include transparent films such as polyethylene resin, acrylic resin, 
polycarbonate resin, copolymer or mixture of polystyrene and 
polycarbonate, or polyethylene terephthalate resin, etc., or glass, and 
its thickness may be 100 .mu.m to 1 mm. 
The surface protective layer 22 is provided as the upper layer on the 
transparent sheet 21, having desirably higher hardness than the 
transparent sheet 21 and also lower refractive index of light than the 
transparent sheet 21, and by selecting so, sensitivity during recording 
and reproduction can be enhanced through the action of preventing the 
reflection of the laser beam during recording and reproduction. 
As the material for the surface protective layer 22, the materials used in 
the method known as the surface curing method may be employed, including, 
for example, cured resins obtained by curing of silicon type, acrylic 
type, melamine type, polyurethane type, epoxy type resins, and metal 
oxides such as SiO.sub.2, as specific examples. 
FIG. 9 is a plan view when the optical recording medium is used as the 
optical card. That is, by forming an optical recording medium 31 in the 
card substrate 30, an optical card can be obtained. More specifically, by 
forming an optical recording medium 31 embedded in the card substrate 30 
(in this case, it is preferred that the surface of the optical recording 
medium 31 may be on the same plane as the card substrate 30 for card 
running stability during recording and reproduction in the recording and 
reproducing device), or forming the optical recording medium 31 by 
adhesion with an adhesive, etc. onto the surface of the card substrate 30, 
an optical card can be obtained. Further, an optical card can be also 
prepared according to the method as shown in Examples as described 
hereinafter. 
The present invention is described below by referring to Examples, but the 
present invention is not limited to these Examples at all. 
EXAMPLE A-1 
A polycarbonate film (produced by Teijin K.K., Japan, trade name: Panlite, 
thickness: 400 .mu.m) was prepared as a transparet sheet (support), and a 
composition for formation of surface protective layer with a composition 
shown below was applied on one surface according to the spiral gravure 
reverse coating method to form a surface protective layer with a thickness 
of 2 .mu.m. 
On the other surface of the transparent sheet, a tracking forming layer 
with a guide groove for tracking, a recording layer and a sensitizing 
layer were successively formed as described below. 
First, 5 parts by weight of a photosensitizer were added to 100 parts by 
weight of an oligoester acrylate (produced by Toa Gosei K.K., Japan, trade 
name M-5700), and the mixture was applied by the roll coating method at a 
ratio of 5 g/m.sup.2, a matrix with the reverse shape of the guide groove 
for tracking was pushed against the coated surface and laminated by use of 
a roll. After cured by irradiation of UV-ray, the matrix was peeled off to 
form a tracking forming layer with a guide groove for tracking. As the 
matrix, a sheet having a tracking guide groove transferred with a UV-ray 
curable resin from a mold was employed. 
On the tracking forming layer, by use of tellurium/copper/lead=80/15/5 
(weight ratio) as the sputtering target, a recording layer of 300 .ANG. 
was formed. Sputtering was effected by use of a high frequency power 
source of 13.56 MHz under the conditions of an output of 100 W and an 
argon gas pressure of 1.times.10.sup.-3 Torr. 
On the recording layer, by use of SiO.sub.2 as the sputtering target, 
according to the sputtering method under otherwise the same conditions as 
in formation of the recording layer, a sensitizing layer with a thickness 
of 1000 .ANG. was formed. 
Separately, a polyvinyl chloride resin film (produced by Mitsubishi Jushi 
K.K., Japan, thickness 350 .mu.m) was prepared, applied with printing of 
predetermined matters, then coated on the surface to be adhered to this 
film with a polyurethane type two-component adhesive (produced by Alps 
Kagaku K.K., Japan, trade name: Alpon) and laminated on the sensitizing 
layer side of the transparent sheet having the above respective layers 
formed thereon by use of a roll to obtain an optical recording medium. 
COMATIVE EXAMPLE A-1 
For comparison, an optical recording medium was obtained in the same manner 
as in Example A-1 except for omitting the sensitizing layer. 
COMATIVE EXAMPLE A-2 
For comparison, an optical recording medium was obtained in the same manner 
as in Example A-1 except for omitting the tracking forming layer and the 
sensitizing layer. 
The optical recording materials obtained in Example A-1 and Comparative 
Example A-1 were stored in a thermostat and humidistat tank of a 
temperature of 40.degree. C. and a relative humidity of 90%, and then 
optical recording was effected on the optical recording materials by 
irradiation of a laser beam from the surface protective layer side under 
the conditions of a wavelength of 830 nm, an output of 7 mw and a pulse 
width of 25 .mu.sec. As the result, in the recording material of Example 
A-1, pits with good shape of 3 .mu.m in pit diameter could be obtained, 
but recording was impossible in the recording material of Comparative 
Example A-1. 
When recording was immediately effected on the recording materials obtained 
in Example A-1 and Comparative Example A-2 under the same conditions as 
described above, pits with good shape of 3 .mu.m in pit diameter could be 
obtained in the recording material of Example A-1, but recording was 
impossible in the recording material of Comparative Example A-2. 
EXAMPLE A-2 
An optical recording medium was obtained in the same manner as in Example 
A-1 except for providing a sensitizing layer with a thickness of 100 .ANG. 
by use of Si.sub.3 N.sub.4 as the sputtering target. When recording was 
effected under the same conditions as described above, pits with good 
shape of 28 .mu.m in diameter could be obtained. 
EXAMPLE A-3 
An optical recording medium was obtained in the same manner as in Example 
A-1 except for providing a sensitizing layer with a thickness of 100 .ANG. 
by use of Si.sub.3 N.sub.4 as the sputtering target. When recording was 
effected under the same conditions as described above, pits with good 
shape of 28 .mu.m in diameter could be obtained. 
EXAMPLE B-1 
A polycarbonate film (produced by Teijin K.K., Japan, trade name: Panlite, 
thickness: 400 .mu.m) was prepared as a transparent sheet (support), and a 
composition for formation of surface protective layer with a composition 
shown below was applied on one surface according to the spiral gravure 
reverse coating method to form a surface protective layer with a thickness 
of 2 .mu.m. 
COMPOSITION FOR FORMATION OF SURFACE PROTECTIVE LAYER: SILICON TYPE 
UV-CURABLE SURFACE CURING MATERIAL (PRODUCED BY TORAY) 
On the other surface of the transparent sheet, a tracking forming layer 
with a guide groove for tracking, a recording layer and a sensitizing 
layer were successively formed as described below. 
First, 5 parts by weight of a photosensitizer were added to 100 parts by 
weight of an oligoester acrylate (produced by Toa Gosei K.K., Japan, trade 
name M-5700), and the mixture was applied by the roll coating method at a 
ratio of 5 g/m.sup.2, a matrix with a reverse shape of the guide groove 
for tracking was pushed against the coated surface and laminated by use of 
a roll. After cured by irradiation of UV-ray, the matrix was peeled off to 
form a tracking forming layer with a guide groove for tracking. As the 
matrix, a sheet having a tracking guide groove transferred with a UV-ray 
curable resin from a mold was employed. 
Next, on the tracking forming layer, by use of tellurium simple substance 
as the sputtering target, a recording layer of 300 .ANG. was formed. 
Sputtering was effected by use of a high frequency power source of 13.56 
MHz under the conditions of an output of 100 W and an argon gas pressure 
of 1.times.10.sup.-3 Torr. 
Next, on the recording layer, by use of SiO.sub.2 as the sputtering target, 
according to the sputtering method under otherwise the same conditions as 
in formation of the recording layer, a sensitizing layer with a thickness 
of 1000 .ANG. was formed. 
Separately, a polyvinyl chloride resin film (produced by Mitsubishi Jushi 
K.K., Japan, thickness 350 .mu.m) was prepared, applied with printing of 
predetermined matters, then coated on the surface to be adhered of this 
film with a polyurethane type two-component adhesive (produced by Alps 
Kagaku K.K., Japan, trade name: Alpon) and laminated on the sensitizing 
layer side of the transparent sheet having the above respective layers 
formed thereon by use of a roll to obtain an optical recording medium. 
COMATIVE EXAMPLE B-1 
For comparison, an optical recording medium was obtained in the same manner 
as in Example B-1 except for omitting the sensitizing layer. 
EXAMPLE B-2 
An optical recording medium was prepared in the same manner as in Example 
B-1 except for using a polycarbonate substrate (thickness 600 .mu.m) 
having tracking unevenness formed thereon according to the injection 
molding method as the transparent sheet. 
TEST EXAMPLE 
On the optical recording media obtained in Example B-1 and Comparative 
Example B-1, by use of a semiconductor of a wavelength of 830 mm and an 
output of 7 mW, writing was effected by varying the pulse width and 
evaluate. 
As the result, in the optical recording medium of Example B-1, as shown in 
FIG. 10, writing becomes possible in the vicinity of the pulse width of 24 
.mu.sec. However, in the optical recording medium of Comparative Example 
1, no writing of data could be done. 
On the other hand, for the optical recording medium of Example B-2, writing 
was effected from the transparent sheet side with a semiconductor laser of 
a wavelength of 830 mm by use of a lens of N.sub.A 0.3, whereby 
substantially the same result as in Example B-1 was obtained. 
EXAMPLE -3 (PREATION EXAMPLE OF OPTICAL CARD) 
A polycarbonate film (produced by Teijin K.K., Japan, trade name: Panlite, 
thickness: 400.mu.) was prepared as a transparent sheet (support), and a 
composition for formation of surface protective layer with a composition 
shown below was applied on one surface according to the spiral gravure 
reverse coating method to form a surface protective layer with a thickness 
of 2 .mu.m. Composition for formation of surface protective layer: 
SILICON TYPE UV-CURABLE SURFACE CURING MATERIAL (PRODUCED BY TORAY) 
On the other surface of the transparent sheet, a tracking forming layer 
with a guide groove for tracking, a recording layer and a sensitizing 
layer were successively formed as described below. 
First, 5 parts by weight of a photosensitizer were added to 100 parts by 
weight of an oligoester acrylate (produced by Toa Gosei K.K., Japan, trade 
name M-5700), and the mixture was applied on the dimensions of 80 
mm.times.20 mm by the roll coating method at a ratio of 5 g/m.sup.2, a 
matrix with a reverse shape of the guide groove for tracking was pushed 
against the coated surface and laminated by use of roll. After cured by 
irradiation of UV-ray, the matrix was peeled off to form a tracking 
forming layer with a guide groove for tracking. As the matrix, a sheet 
having a tracking guide groove transferred with a UV-ray curable resin 
from a mold was employed. 
Next, on the tracking forming layer, by use of tellurium simple substance 
as the sputtering target, a recording layer of 300 .ANG. was formed. 
Sputtering was effected by use of a high frequency power source of 13.56 
MHz under the conditions of an output of 100 W and an argon gas pressure 
of 1.times.10.sup.-3 Torr. 
Next, on the recording layer, by use of SiO.sub.2 as the sputtering target, 
according to the sputtering method under otherwise the same conditions as 
in formation of the recording layer, a sensitizing layer with a thickness 
of 1000 .ANG. was formed. 
Separately, a polyvinyl chloride resin film (produced by Mitsubishi Jushi 
K.K., Japan, thickness 350 .mu.m) was prepared, applied with printing of 
predetermined matters, then coated on the surface to be adhered of this 
film with a polyurethane type two-component adhesive (produced by Alps 
Kagaku K.K., Japan, trade name: Alpon) with a thickness of 10.mu. and 
laminated on the sensitizing layer side of the transparent sheet having 
the above respective layers formed thereon by use of a roll to obtain an 
optical recording medium. The optical recording medium obtained was 
punched into card dimensions to obtain an optical card with a thickness of 
0.75 mm, having an optical recording portion (80 mm.times.20 mm). 
EXAMPLE C-1 
As a transparent sheet (support), an acrylic resin plate (produced by Nitto 
Kogyo Jushi, Japan, thickness 400 .mu.m) was prepared and a tracking 
forming layer with a guide groove for tracking, a recording layer and a 
sensitizing layer were successively formed. 
First, 95 parts by weight of an oligoester acrylate (produced by Toa Gosei 
Kagaku K.K., Japan, trade name M-8030) added with 5 parts by weight of a 
photosensitizer were sandwiched between an acrylic resin plate and a 
matrix with the reverse shape of the guide groove for tracking, and 
laminated by use of a roll to 5 g/m.sup.2. After curing of the oligoester 
acrylate by irradiation of UV-ray, the matrix was peeled off to form a 
tracking forming layer with a guide groove for tracking. 
On the tracking forming layer, by use of tellurium as the sputtering 
target, a recording layer of 350 .ANG. was formed according to the 
sputtering method. Sputtering was effected by use of a high frequency 
power source under the conditions of an output of 50W and an argon gas 
pressure of 1.times.10.sup.-2 Torr. 
On the recording layer, 1 part by weight of a polyvinyl acetate (produced 
by Nippon Gosei Kagaku K.K., Japan, trade name Goseneel K50-Y2) added with 
3 parts by weight of methyl isobutyl ketone under thorough stirring was 
applied by spin coating to form a sensitizing layer. The thickness of the 
sensitizing layer was 1 to 2 .mu.m. 
Separately, a polyvinyl chloride resin film (produced by Mitsubishi Jushi 
K.K., Japan, thickness 350 .mu.m) was prepared, applied with printing of 
predetermined matters, then coated on the surface of the film to be 
adhered with a polyurethane type two-component adhesive (produced by Toray 
K.K., Japan, trade name HU1226) and laminated on the sensitizing layer 
side of the sheet having the above respective layers formed thereon by use 
of a roll, to obtain an optical recording medium. 
When the optical recording medium obtained was irradiated from the 
transparent sheet side with a semiconductor laser of a wavelength of 830 
nm by use of a lens of N.sub.A 0.3, pits with good hole shape of about 2.2 
.mu.m.phi. could be written at an output of 7 mW with a pulse width of 2 
.mu.sec. 
EXAMPLE C-2 
An optical recording medium was obtained similarly as in Example C-1 by 
adding 10% by weight of a near IR-ray absorbing dye (produced by Mitsui 
Toatsu Fine K.K., Japan, PA-1006) into the polyvinyl acetate resin of the 
sensitizing layer. 
When the optical recording medium was irradiated from the transparent sheet 
side with a semiconductor laser of a wavelength of 830 nm by use of a lens 
of N.sub.A 0.3, pits with good hole shape of about 2.2 .mu.m.phi. could be 
written at an output of 7 mW with a pulse width of 3 .mu.sec. 
EXAMPLE C-3 
An optical recording medium was obtained similarly as in Example C-1 by use 
of an alloy with a composition ratio of Te:80 percent, Cu:15 percent and 
Pb:5 percent as the sputtering target. 
When the optical recording medium was irradiated from the transparent sheet 
side with a semicondutor laser of a wavelength of 830 nm by use of a lens 
of N.sub.A 0.3, substantially the same results as in Example C-1 were 
obtained. 
EXAMPLE C-4 
An optical recording medium was obtained similarly as in Example C-1 by use 
of an acrylic resin plate having tracking unevenness formed thereon 
according to the injection molding method (thickness 600 .mu.m) as the 
transparent sheet. 
When the optical recording medium was irradiated from the transparent sheet 
side with a semiconductor laser of a wavelength of 830 nm by use of a lens 
of N.sub.A 0.3, substantially the same results as in Example C-1 were 
obtained. 
EXAMPLE C-5 (PREATION EXAMPLE OF OPTICAL CARD) 
The optical recording media obtained in Examples C-1 to C-4 were 
respectively punched into card dimensions to obtain optical cards having a 
thickness of 0.75 mm and an optical recording portion (80 mm.times.20 mm). 
EXAMPLE D-1 
On an acrylic resin support with a thickness of 0.8 mm provided with 
unevenness for beam following (tracking), a thin Te film with a thickness 
of 600 .ANG. was provided according to the sputtering method to prepare a 
recording medium. As the target used for sputtering, Te of 99.9% purity 
was employed. Sputtering was effected in Ar atmosphere of 
1.0.times.10.sup.-2 Torr, and the Te film deposition speed at this time 
was 25 .ANG./sec. 
On the recording layer thus provided, a sensitizing layer of a silicon 
containing organic material with a thickness of 1000 .ANG. according to 
the plasma polymerization method was provided. The plasma polymerization 
method is the chemical vapor deposition method in which a starting 
material contained in a carrier gas is delivered into a vessel evacuated 
to vacuum, discharging is effected while maintaining a constant pressure 
and a film is formed as the result of chemical reaction of the active 
species, radicals, etc. formed by discharging on a substrate of low 
temperature. In this Example, hydrogen gas was used as the carrier gas, 
and tetramethylsilane ((CH.sub.3).sub.4 Si) as the starting material. The 
starting material was contained in the carrier gas as follows. That is, 
hydrogen gas of 1 kg/cm.sup.2 was bubbled into liquid tetramethylsilane 
maintained at 0.degree. C. at a flow rate of 40 cc/min., whereby 
tetramethylsilane was contained as the vapor in the hydrogen gas. The flow 
rate of the gaseous mixture of hydrogen and tetramethylsilane at this time 
was 53 cc/min. 
The gas mixture obtained as described above was introduced into a vacuum 
vessel and the pressure was maintained at 0.5 Torr by controlling the 
discharging valve. The pressure was measured by a differential pressure 
type vacuum gauge. Discharging was generated by applying a high frequency 
of 125 KHz between the two parallel flat plate electrodes placed 
horizontally. At this time, the film deposition speed was 10 .ANG./sec. 
The film obtained was found to have an amorphous structure in which 
silicon, carbon and hydrogen were crosslinked, as determined by 
IR-absorption analysis and photoelectric spectroscopic analysis. 
The recording diameter when writing was effected in the optical recording 
medium as obtained above at an oscillation wavelength of 830 nm and an 
input power into the medium of 7 mW was as shown in FIG. 11. The optical 
recording medium was adhered to a vinyl chloride resin with the 
sensitizing layer side as the inner side. As the adhesive layer, an 
urethane type adhesive (Hisole produced by Toray) was employed. 
The recording diameter when writing was effected with laser onto the sealed 
structure type optical recording medium was as shown in FIG. 12. By 
sealing, although reduction of recording diameter occurs, even the case of 
practically sealed structure has a satisfactory relationship between 
recording diameter and recording speed. 
EXAMPLE D-2 
As a transparent sheet (support), an acrylic resin plate (produced by Nitto 
Kogyo Jushi, Japan, thickness 400 .mu.m) was prepared and a tracking 
forming layer with a guide groove for tracking a recording layer and a 
sensitizing layer were successively formed. 
First, 95 parts by weight of an oligoester acrylate (produced by Toa Gosei 
Kagaku K.K., Japan, trade name M-8030) added with 5 parts by weight of a 
photosensitizer were sandwiched between an acrylic resin plate and a 
matrix with the reverse shape of the guide groove for tracking, and 
laminated by use of a roll to 5 g/m.sup.2. After curing of the oligoester 
acrylate by irradiation of UV-ray, the matrix was peeled off to form a 
tracking forming layer with a guide groove for tracking. 
On the tracking forming layer, a thin Te film with a thickness of 600 .ANG. 
was provided according to the sputtering method to prepare a recording 
layer. As the target used for sputtering, Te of 99.9% purity was employed. 
Sputtering was effected in Ar atmosphere of 10.times.10.sup.-2 Torr at a 
Te film deposition speed of 25 .ANG./sec. 
On the recording layer thus provided, a sensitizing layer of a silicon 
containing organic material with a thickness of 1000 .ANG. according to 
the plasma polymerization method was provided. The plasma polymerization 
method is the chemical vapor deposition method in which a starting 
material contained in a carrier gas is delivered into a vessel evacuated 
to vacuum, discharging is effected while maintaining a constant pressure 
and a film is formed as the result of chemical reaction of the active 
species, radicals, etc. formed by discharging on a substrate of low 
temperature. In this Example, hydrogen gas was used as the carrier gas, 
and tetramethylsilane ((CH.sub.3).sub.4 Si) as the starting material. The 
starting material was contained in the carrier gas as follows. That is, 
hydrogen gas of 1 kg/cm.sup.2 was bubbled into liquid tetramethylsilane 
maintained at 0.degree. C. at a flow rate of 40 cc/min., whereby 
tetramethylsilane was contained as the vapor in the hydrogen gas. The flow 
rate of the gaseous mixture of hydrogen and tetramethylsilane at this time 
was 53 cc/min. 
The gas mixture obtained as described above was introduced into a vacuum 
vessel and the pressure was maintained at 0.500 Torr by controlling the 
discharging valve. The pressure was measured by a differential pressure 
type vacuum gauge. Discharging was generated by applying a high frequency 
of 125 KHz between the two parallel flat plate electrodes placed 
horizontally. At this time, the film deposition speed was 10 .ANG./sec. 
The film obtained was found to have an amorphous structure in which 
silicon, carbon and hydrogen were crosslinked, as determined by 
IR-absorption analysis and photoelectric spectroscopic analysis. 
The recording diameter when writing was effected in the optical recording 
medium as obtained above at an oscillation wavelength of 830 nm and an 
input power into the medium of 7 mW was as shown in FIG. 11. The optical 
recording medium was adhered to a vinyl chloride resin with the 
sensitizing layer side as the inner side. As the adhesive layer, an 
urethane type adhesive (Hisole produced by Toray) was employed. 
The recording diameter when writing was effected with laser onto the sealed 
structure type optical recording medium was as shown in FIG. 12. By 
sealing, although reduction of recording diameter occurs, even the case of 
practically sealed structure has a satisfactory relationship between 
recording diameter and recording speed. 
COMATIVE EXAMPLE D-1 
In the same manner as in Example D-1, a thin Te film with a thickness of 
600 .ANG. was provided on an acrylic resin support according to the 
sputtering method to provide a recording layer for an optical recording 
material. As different from Example D-1, without provision of a 
sensitizing layer, the Te layer was adhered to the vinyl chloride resin 
with the use of an urethane type adhesive to prepare an optical recording 
medium of the sealed structure. Writing was effected on the sealed 
structure optical recording medium similarly as in the case of Example 
D-1. The relationship of the writing hole diameter relative to the laser 
pulse time width was as shown in FIG. 13. 
As compared with Example D-1, the difference is clear and it takes 10-fold 
or more of the laser pulse width in Comparative Example D-1. Thus, 
Comparative Example is unsuitable for writing as compared with Example. 
EXAMPLE D-3 
An optical recording medium obtained according to the same method as in 
Example D-1 (however, the dimensions of the optical recording portion were 
made 80 mm.times.20 mm) was punched into card dimensions to obtain an 
optical card having a thickness of 0.75 mm and an optical recording 
portion (80 mm.times.20 mm). 
EXAMPLE E-1 
A polycarbonate film (produced by Teijin K.K., Japan, trade name: Panlite, 
thickness: 400 .mu.m) was prepared as a transparent sheet (support), and a 
composition for formation of surface protective layer comprising a 
silicone type UV-curable curing material (produced by Toray) was applied 
on one surface according to the spiral gravure reverse coating method to 
form a surface protective layer with a thickness of 2 .mu.m. 
On the other surface of the transparent sheet, a tracking forming layer 
with a guide groove for tracking, a recording layer and a sensitizing 
layer were successively formed as described below. 
First, 5 parts by weight of a photosensitizer were added to 100 parts by 
weight of an oligoester acrylate (produced by Toa Gosei K.K., Japan, trade 
name M-5700), and the mixture was applied by the roll coating method at a 
ratio of 5 g/m.sup.2, a matrix with the reverse shape of the guide groove 
for tracking was pushed against the coated surface and laminated by use of 
a roll. After cured by irradiation of UV-ray, the matrix was peeled off to 
form a tracking forming layer with a guide groove for tracking. As the 
matrix, a sheet having a tracking guide groove transferred with a UV-ray 
curable resin from a mold was employed. 
Next, on the tracking forming layer, according to the sputtering method by 
use of tellurium simple substance as the sputtering target, a recording 
layer of 300 .ANG. was formed. Sputtering was effected by use of a high 
frequency power source of 13.56 MHz under the conditions of an output of 
100 W and an argon gas pressure of 1.times.10.sup.-3 Torr. 
Next, on the recording layer, a thin MgF.sub.2 film was formed with a 
thickness of 500 .ANG. according to the resistance heating vapor 
deposition to provide a sensitizing layer. The resistance heating vapor 
deposition was effected under the condition of 1.times.10.sup.-5 Torr. 
Separately, a polyvinyl chloride resin film (produced by Mitsubishi Jushi 
K.K., Japan, thickness 350 .mu.m) was prepared, applied with printing of 
predetermined matters, then coated on the surface to be adhered of this 
film with a polyurethane type two-component adhesive (produced by Alps 
Kagaku K.K., Japan, trade name: Alpon) and laminated on the sensitizing 
layer side of the transparent sheet having the above respective layers 
formed thereon by use of a roll to obtain an optical recording medium. 
COMATIVE EXAMPLE E-1 
For comparison, an optical recording medium was obtained in the same manner 
as in Example E-1 except for omitting the sensitizing layer. 
EXAMPLE E-2 
According to the same method as in Example E-1 except for using a 
polycarbonate substrate (thickness 600 .mu.m) having a tracking forming 
layer formed thereon according to the injection molding as the transparent 
sheet, an optical recording medium was prepared. 
EXAMPLE E-3 
According to the same method as in Example E-1 except for providing a 
recording layer of 350 .ANG. according to the sputtering method by use of 
Te simple substance as the light reflective layer. 
TEST EXAMPLE 
For the optical recording media obtained in Example E-1 and Comparative 
Example E-1, writing was effected by use of a semiconductor laser of a 
wavelength of 830 mm and an output of 7 mW and evaluated. 
As the result, in the optical recording medium of Example E-1, as shown in 
FIG. 14, writing becomes possible from the vicinity of a pulse width of 24 
.mu.sec. However, in the optical recording medium of Comparative Example 
E-1, no writing of data was possible. 
On the other hand, for the optical recording media of Examples E-2 and E-3, 
when writing was effected from the transparent sheet side with a 
semiconductor laser of a wavelength of 830 mm by use of a lens of N.sub.A 
0.3, substantially the same results as in Example E-1 were obtained. 
EXAMPLE E-4 
An optical recording medium obtained according to the same method as in 
Example E-1 (however, the dimensions of the optical recording portion were 
made 80 mm.times.20 mm) was punched into card dimensions to obtain an 
optical card having a thickness of 0.75 mm and an optical recording 
portion (80 mm.times.20 mm). 
EXAMPLE F-1 
A polycarbonate film (produced by Teijin K.K., Japan, trade name: Panlite, 
thickness: 400 .mu.m) was prepared as a transparent sheet, and a 
composition for formation of surface protective layer with a composition 
shown below was applied on one surface according to the spiral gravure 
reverse coating method to form a surface protective layer with a thickness 
of 2 .mu.m. 
COMPOSITION FOR FORMATION OF SURFACE PROTECTIVE LAYER: SILICONE TYPE 
UV-CURABLE SURFACE CURING AGENT (PRODUCED BY TORAY) 
On the other surface of the transparent sheet, a tracking forming layer 
with a guide groove for tracking, a recording layer and a sensitizing 
layer were successively formed as described below. 
First, 5 parts by weight of a photosensitizer were added to 100 parts by 
weight of an oligoester acrylate (produced by Toa Gosei K.K., Japan, trade 
name M-5700), and the mixture was applied by the roll coating method at a 
ratio of 5 g/m.sup.2, a matrix with the reverse shape of the guide groove 
for tracking was pushed against the coated surface and laminated by use of 
a roll. After cured by irradiation of UV-ray, the matrix was peeled off to 
form a tracking forming layer with a guide groove for tracking. As the 
matrix, a sheet having a tracking guide groove transferred with a UV-ray 
curable resin from a mold was employed. 
On the tracking forming layer, by use of tellurium/copper/lead=80/15/5 
(weight ratio) as the sputtering target, a recording layer of 300 .ANG. 
was formed. Sputtering was effected by use of a high frequency power 
source of 13.56 MHz under the conditions of an output of 100 W and an 
argon gas pressure of 1.times.10.sup.-3 Torr. 
Separately, a polyvinyl chloride resin film (produced by Mitsubishi Jushi 
K.K., thickness 350 .mu.m) was prepared, applied with printing of 
predetermined matters, then coated on the surface to be adhered of this 
film with a hot melt type adhesive of which the base polymer is a vinyl 
resin (produced by Sekisui Kagaku K.K., Japan, trade name: Esdine 8900) 
with a thickness of 10.mu. to form an adhesive layer. With the surface of 
the adhesive layer of the polyvinyl chloride film being superposed on the 
surface of the recording layer of the transparent sheet having the above 
respective layers formed thereon, both were laminated by use of a roll to 
obtain an optical recording medium. 
COMATIVE EXAMPLE F-1 
For comparison, an optical recording medium was obtained in the same manner 
as in Example F-1 except for using a polyurethane type two-component 
adhesive (produced by Alps Kagaku, Japan, trade name: Alpon) as the 
adhesive. 
When writing was effected on the optical recording media obtained in 
Example F-1 and Comparative Example F-1 with a semiconductor laser of a 
wavelength of 830 nm and an output of 20 mW by varying the pulse width and 
evaluated, writing was possible in Example F-1 as shown in FIG. 15 from 
the condition of the pulse width of 2 .mu.sec, but writing was impossible 
in the recording medium of Comparative Example F-1. 
EXAMPLE F-2 
An optical recording medium was obtained in the same manner as in Example 
F-1 except for forming a recording layer of 350 .ANG. according to the 
sputtering method by use of Te simple substance. When writing was effected 
by use of the optical recording medium obtained under the same conditions 
as in Comparative Example F-1, writing was possible from the pulse width 
of 3 .mu.sec. 
EXAMPLE F-3 
An optical recording medium was obtained in the same manner as in Example 
F-1 except for using a polycarbonate sheet formed by the injection molding 
method (thickness 600 .mu.m) as the transparent sheet layer. When writing 
was effected on the optical recording medium by irradiation of a 
semiconductor laser of a wavelength of 830 nm from the transparent sheet 
side with the use of a lens of N.sub.A 0.3, writing could be done 
substantially similarly as in Example F-1. 
EXAMPLE F-4 (PREATION EXAMPLE OF OPTICAL CARD) 
A polycarbonate film (produced by Teijin K.K., Japan, trade name: Panlite, 
thickness: 400 .mu.m) was prepared as a transparent sheet, and a 
composition for formation of surface protective layer with a composition 
shown below was applied on one surface according to the spiral gravure 
reverse coating method to form a surface protective layer with a thickness 
of 2 .mu.m. 
COMPOSITION FOR FORMATION OF SURFACE PROTECTIVE LAYER: SILICONE TYPE 
UV-CURABLE SURFACE CURING AGENT (PRODUCED BY TORAY) 
On the other surface of the transparent sheet, a tracking forming layer 
with a guide groove for tracking, a recording layer and a sensitizing 
layer were successively formed as described below. 
First, 5 parts by weight of a photosensitizer were added to 100 parts by 
weight of an oligoester acrylate (produced by Toa Gosei K.K., Japan, trade 
name M-5700), and the mixture was applied by the roll coating method at a 
ratio of 5 g/m.sup.2 to the dimensions of 80 mm.times.20 mm, a matrix with 
the reverse shape of the guide groove for tracking was pushed against the 
coated surface and laminated by use of a roll. After cured by irradiation 
of UV-ray, the matrix was peeled off to form a tracking forming layer with 
a guide groove for tracking. As the matrix, a sheet having a tracking 
guide groove transferred with a UV-ray curable resin from a mold was 
employed. 
Next, on the tracking forming layer, by use of 
tellurium/copper/lead=80/15/5 (weight ratio) as the sputtering target, a 
recording layer of 300 .ANG. was formed. Sputtering was effected by use of 
a high frequency power source of 13.56 MHz under the conditions of an 
output of 100 W and an argon gas pressure of 1.times.10.sup.-3 Torr. 
Separately, a polyvinyl chloride resin film (produced by Mitsubishi Jushi 
K.K., Japan, thickness 350 .mu.m) was prepared, applied with printing of 
predetermined matters, then coated on the surface to be adhered of this 
film with a hot melt type adhesive of which the base polymer is a 
polyester resin (produced by Diabond Kogyo K.K., Japan, trade name: 
Meltron E801) with a thickness of 10.mu. to form an adhesive layer. With 
the surface of the adhesive layer of the polyvinyl chloride film being 
superposed on the surface of the recording layer of the transparent sheet 
having the above respective layers formed thereon, both were laminated by 
use of a roll to obtain an optical recording medium. The optical recording 
medium obtained was punched into card dimensions to obtain an optical card 
having a thickness of 0.75 mm and an optical recording portion (80 
mm.times.20 mm). 
EXAMPLE G-1 
By use of an acrylic plate (thickness 0.4 mm) provided with fine unevenness 
for tracking as the support, a recording layer (TeO.sub.x) with a 
thickness of 500 .ANG. was provided on the support surface according to 
the reactive sputtering method. As the target in this case, Te of 99.99% 
purity was employed. 
The above reactive sputtering was conducted in an atmosphere of 85% of 
argon, 14% of oxygen and a pressure of 5.times.10.sup.-3 Torr. 
As the next step, subsequently a sensitizing layer (TeO.sub.x) with a 
thickness of 500 .ANG. was provided on the recording layer obtained above 
in an atmosphere of 58% of argon, 42% of oxygen and a pressure of 
5.times.10.sup.-3 Torr. 
In the above respective layers, x=0.7, y=1.8. 
For the optical recording medium obtained, information recording was 
performed. 
High speed, high sensitivity recording of 1 .mu.m or less could be done 
with a laser beam of 830 nm and 5 mW. The information pit formed had a 
good recorded shape, and there was no change observed in sensitivity and 
stability when left to stand for about one month in an atmosphere of 
60.degree. C. and a relative humidity of 90%. 
On the surface of the sensitizing layer of the optical recording medium was 
further bonded and integrated a vinyl chloride substrate with a thickness 
of 0.32 mm through a two-liquid curable urethane type adhesive layer, 
followed by molding into a card size to obtain an optical record which is 
another embodiment of the optical recording medium. 
When information recording was performed on this optical record, high 
speed, high sensitivity recording of 3 .mu.s or less could be done with a 
laser beam of 830 nm and 5 mW. There was no change observed in sensitivity 
and stability, when left to stand for about 3 months in an atmosphere of 
60.degree. C. and a relative humidity of 90%. 
COMATIVE TEST EXAMPLE 
On a support thin films of Te simple substance, a weak oxide of Te 
(TeO.sub.0.5) and a strong oxide of Te (TeO.sub.1.8) were respectively 
formed, and recording sensitivity and weathering resistance (when left to 
stand at 40.degree. C. in 90% relative humidity) were examined to obtain 
the following results. 
______________________________________ 
Recording layer 
Sensitivity 
Weathering resistance 
______________________________________ 
Te Good Reflectance lowered within 100 
hours 
Te weak oxide 
Good No change after 500 hours or 
longer 
Te strong oxide 
Not good the same as above 
______________________________________ 
As described above, the recording layers of Te and Te weak oxide exhibited 
good recording sensitivities. However, in weathering resistance test, Te 
thin film exhibited remarkable lowering in reflectance within about 100 
hours, and thereafter the thin film became completely matte. On the other 
hand, the recording layer comprising the Te strong film had excellent 
weathering resistance, but no writing of information could be effected. 
EXAMPLE G-2 
On a support made of PMMA with a thickness of 0.6 mm, a recording layer and 
a sensitizing layer were formed by the method as described below. 
A vacuum vapor deposition device having a hot electron collision type ion 
gun arranged therein was preliminarily evacuated to a vacuum degree of 
10.sup.-5 Torr, and then the vacuum degree was maintained at 
8.times.10.sup.-5 Torr by introducing oxygen gas into the device. 
Next, vacuum vapor deposition of Te and irradiation of ion beam onto the 
support were effected at the same time. 
The film preparation conditions were as follows: 
Ion gun: 
Acceleration voltage: 500 V 
Oxygen ion current density on substrate: 50 .mu.A/cm.sup.2 
Film forming speed of Te: 10 .ANG./sec. 
Film thickness: 500 .ANG. 
Next, by maintaining the vacuum degree in the device at 1.0.times.10.sup.-4 
Torr by introducing oxygen gas into the device, a sensitizing layer was 
further subsequently formed on the surface of the recording layer formed 
as described above. The film preparation conditions were as follows: 
Ion gun: 
Acceleration voltage: 500 V 
Oxygen ion current density on substrate: 500 .eta.A/cm.sup.2 
Film forming speed of Te: 10 .ANG./sec 
Film thickness: 1000 .ANG. 
The compositions of the respective thin films obtained were TeO.sub.0.5 for 
the recording layer and TeO.sub.1.2 for the sensitizing layer. 
For the optical recording medium of the present invention thus obtained, 
information recording sensitivity and stability were examined according to 
the same method as in the foregoing Example G-1, to obtain substantially 
the same results as in Example G-1. 
EXAMPLE H-1 
A subbing agent (produced by Shinetsu Kagaku Kogyo, Japan, Primer PC-4) was 
applied by gravure coating on a polycarbonate film with a thickness of 400 
.mu.m, then a silicone type surface curing agent (produced by Shinetsu 
Kagaku Kogyo, Japan, X-12-2150) by gravure coating threreon, followed by 
curing at 100.degree. C. for one minute to obtain a surface cured layer. 
On the back surface of the above polycarbonate film, a coating solution 
for formation of a photosensitive material layer was provided partially by 
gravure coating. The amount of the coating solution for formation of 
photosensitive material coated was 3 g/m.sup.2. 
______________________________________ 
Composition of coating solution for formation of 
photosensitive material: 
______________________________________ 
10% methyl ethyl ketone solution of 
20 wt. parts 
vinyl methyl ether/maleic anhydride 
ester copolymer resin (Gentretz 
AN139, produced by G.A.F. Corp.) 
20% methyl ethyl ketone solution 
20 wt. parts 
of polyvinyl acetate resin (Ethnyl 
C-2, produced by Sekisui Kagaku) 
25% methylcellosolve solution of an 
12 wt. parts 
acrylic resin (L-40, produced by 
Soken Kagaku) 
0.1% methylcellosolve solution of 
38 wt. parts 
palladium chloride (PdCl.sub.2 : conc. 
HCl: methylcellosolve = 1:10:1000) 
38 wt. parts 
10% methylcellosolve solution of 4- 
10 wt. parts 
morpholino-2,5-dibutoxybenzene- 
diazoniumborofluoride (DH300 BF.sub.4, 
produced by Daito Kagaku) 
______________________________________ 
Next, on the surface of the photosensitive layer thus formed, the mask 
surface of a photomask subjected to negative patterning with an 
arrangement at a pitch of 20 .mu.m between the rows aligned with a pitch 
of 15 .mu.m of the dots of 15 .mu.m.times.5 .mu.m was closely contacted, 
and exposure was effected from the photomask side by an ultra-high 
pressure mercury lamp (3 kW, distance 1 m) for 10 seconds. 
This photomask pattern used in this case was obtained by the photoetching 
method. It was prepared by coating and drying a photoresist (AZ-1350, 
produced by Sipley) on a thin Cr thin film formed according to the 
sputtering method on a glass plate, then effecting irradiation of He-CD 
laser according to the above arrangement with a narrowed beam diameter of 
2 .mu.m on the X-Y stage on the dried surface controlled in position, 
treating the exposed pattern with a resist developer (produced by Sipley) 
at 130.degree. C. for 25 minutes, followed by etching with a ferric 
chloride solution to make the dot portions transmissive. 
Subsequently, the photosensitive material layer subjected to pattern 
exposure as described above was successively dipped in the treating 
solutions [A], [B] having the following compositions in this order for 60 
seconds, and 80 seconds (treatment temperature 30.degree. C.). 
______________________________________ 
[A] Siba nickel (produced by Okuno Seiyaku, Japan) 
Boron type reducing agent 0.5 g 
Nickel sulfate 3.0 g 
Sodium citrate 1.0 g 
Water 95.5 g 
[B] 1:1 mixture of TMP chemical nickel-A and 
TMP chemical nickel-B 
Nickel sulfate 9.0 g 
Sodium hypophosphite 7.0 g 
Aqueous NH.sub.3 solution (28%) 
6.5 g 
Sodium citrate 10.0 g 
Water 67.5 g 
______________________________________ 
After dipping, the layer was washed with water and dried to obtain a first 
recording layer having a positive pattern comprising a black light 
intercepting portion in the light transmissive portion. 
On the first recording layer subjected to patterning as described above, a 
Te-Cu-Pb alloy (sputtering target composition ratio of 80:15:5 in terms of 
molar ratio) was sputtered to form a second recording layer, thus 
obtaining an optical recording material. In this case, the second layer of 
the thin Te-Cu-Pb film was formed only on the portion where there was the 
first recording layer, and not on the peripheral marginal portion. 
Separately from the above optical recording materials, first a transfer 
film having an acrylic resin (produced by Toyo Morton, Japan, Adcoat 
AD33B4) coated and dried onto a polyester film with a thickness of 25 
.mu.m was prepared. Next, with the coated surface of the transfer film 
being closely contacted with the second recording layer surface of the 
above optical recording material, the composite was passed through the 
heat rolls with a surface temperature of 100.degree. C. at a speed of 1 
cm/sec, and after the polyester film was peeled off to form a sensitizing 
layer by transferring only the above acrylic resin onto the second 
recording layer of the above optical recording material. 
On the other hand, the card substrate was prepared as described below. 
First, on both the surfaces of a white rigid polyvinyl chloride resin 
sheet (thickness: 200 .mu.m), a pattern of letters and figure was provided 
by screen printing, and further separately from this, a magnetic recording 
layer was provided with a width of 6.5 mm on a part of one surface of a 
transparent rigid polyvinyl chloride (thickness: 100 .mu.m), and with the 
above printed white rigid polyvinyl chloride resin sheet superposed on the 
surface on the side where no magnetic recording layer is provided, to be 
sandwiched between the two sheets of stainless steel plates, both were 
fused together by a pressing machine by heating under pressurization at 
140.degree. C. for 30 minutes to obtain a card substrate. 
The optical recording material on the card substrate prepared as described 
above were superposed on the second recording layer of the optical 
recording material and the white rigid polyvinyl chloride resin sheet 
surface of the card substrate through an urethane type resin adhesive 
(produced by Alps Kagaku Sangyo, Japan, Arbon EU-4200: EHU-4200=10:1, 
weight ratio), and pressure adhered by use of rolls, and left to stand for 
24 hours and punched out into the predetermined dimensions by means of a 
punching mold to obtain an optical card. 
EXAMPLE H-2 
Similarly as described in Example H-1, iron-phthalocyanine which is a dye 
was provided on the surface of the second recording layer as the 
sensitizing layer to obtain an optical card. 
EXAMPLE H-3 
Similarly as described in Example H-1, an optical recording material was 
obtained, and a coating solution having 5 parts by weight of carbon black 
mixed and dispersed in 100 parts by weight of an acrylic resin (Dianal LR 
1215, produced by Mitsubishi Rayon K.K., Japan) was provided as the 
sensitizing layer on the second recording layer of the above optical 
recording material to obtain an optical card. 
EXAMPLE I-1 
On a polycarbonate film with a thickness of 400 .mu.m, a subbing treating 
agent (Primer PC-4, produced by Shinetsu Kagaku Kogyo K.K., Japan) was 
gravure coated, and then a silicon type surface curing agent (X-12-2150, 
produced by Shinetsu Kagaku Kogyo) was gravure coated thereon, followed by 
curing at 100.degree. C. for 1 minute to obtain a surface cured layer. On 
the back surface of the above polycarbonate film, a coating solution for 
formation of a light-sensitive layer with a composition shown below was 
partially provided by gravure coating. The amount of the coating solution 
for formation of light-sensitive material was 3 g/m.sup.3 on drying. 
______________________________________ 
Composition of coating solution for formation of light- 
sensitive material 
______________________________________ 
Vinyl methyl ether/maleic anhydride 
20 wt. parts 
ester copolymer resin (produced 
by G.A.F. Corp., Gantrez AN139) 
10% methyl ethyl ketone solution 
Polyvinyl acetate resin (produced by 
20 wt. parts 
Sekisui Kagaku K.K., Japan, 
Ethneel C-2) 20% methyl ethyl 
ketone solution 
Acrylic resin (produced by Soken Kagaku, 
12 wt. parts 
Japan, L-40) 25% methyl cellosolve 
solution 
Palladium chloride 0.1% methyl 
38 wt. parts 
cellosolve solution PdCl.sub.2 : 
conc. hydrochloric acid: 
methyl cellosolve = 1:10:1000) 
4-morpholino-2,5-dibutoxybenzenedi- 
10 wt. parts 
azonium borofluoride (produced 
by Daito Kagaku, Japan, DH300 BF.sub.4) 
10% methyl cellosolve solution 
______________________________________ 
Next, on the surface of the light-sensitive material layer thus formed, the 
mask surface of a photomask subjected to negative patterning with an 
arrangement of the rows of the dots of 15 .mu.m.times.5 .mu.m aligned at a 
pitch of 15 .mu.m with a pitch between the rows of 20 .mu.m was closely 
contacted, and exposed from the photomask side via ultra-high pressure 
mercury lamp (3 kW, distance: 1 m) for 10 seconds. 
The photomask pattern used in this case was obtained by the photoetching 
method, and prepared by coating a photoresist (produced by Sipley AZ-1350) 
on the Cr thin film formed by the sputtering method on a glass plate, 
followed by drying, and narrowing He-Cd laser to a beam diameter of 2 
.mu.m on the X-Y stage controlled in position on that surface, effecting 
patterning according to the above arrangement, treating the resist with a 
resist developer (produced by Sipley), heat treating the developed resist 
at 130.degree. C. for 25 minutes, followed by etching with a ferric 
chloride solution to make the dot portion transmissive. 
Subsequently, the light-sensitive material layer subjected to pattern 
exposure as described above was dipped in the processing solutions [A], 
[B] having the following compositions in this order to be dipped therein 
for 60 seconds and 80 seconds, respectively. (processing temperature 
30.degree. C.) 
______________________________________ 
[A] Siba nickel (produced by Okuno Seiyaku, Japan) 
Boron type reducing agent 0.5 g 
Nickel sulfate 3.0 g 
Sodium citrate 1.0 g 
Water 95.5 g 
[B] 1:1 mixture of TMP chemical nickel-A 
and TMP chemical nickel-B 
Nickel sulfate 9.0 g 
Sodium hypophosphite 7.0 g 
Aqueous NH.sub.3 solution (28%) 
6.5 g 
Sodium citrate 10.0 g 
Water 67.5 g 
______________________________________ 
After dipping, water washing and drying were performed to obtain a first 
recording layer having a positive pattern comprising a black 
light-intercepting portion in the light-transmitting portion was obtained. 
On the first recording layer subjected to patterning as described above, a 
second recording layer was formed by sputtering of a Te-Cu-Pb alloy 
(sputtering target composition ratio was 80:15:5 in terms of molar ratio) 
to obtain an optical recording material. In this case, the second 
recording layer of the Te-Cu-Po thin film was formed only on the portion 
where the first recording layer existed, and not formed at the peripheral 
portion. 
Separately from the above optical recording material, first, a transfer 
film having an acrylic resin (produced by Toyo Morton, Adcoat AD33B4) 
coated and dried on a polyester film with a thickness of 25 .mu.m was 
prepared. Next, with the coated surface of the transfer film being closely 
contacted on the second recording layer surface of the above optical 
recording material, the composite was passed through the heat rolls of 
100.degree. C. at a speed of 1 cm/sec and thereafter the polyester film 
was peeled off, and only the above acrylic resin was transferred onto the 
surface of the second recording layer of the above optical recording 
material to form a sensitizing layer. 
EXAMPLE I-2 
An optical recording material was obtained similarly as in Example I-1, and 
an iron-phthalocyanine which is a dye was provided as the sensitizing 
layer on the surface of the second recording layer to obtain an optical 
recording material. 
EXAMPLE I-3 
Similarly as described in Example I-1, an optical recording material was 
obtained and a coating solution having 5 parts by weight of carbon black 
mixed and dispersed in 100 parts by weight of an acrylic resin (Dianal LR 
1215, produced by Mitsubishi Rayon) provided as the sensitizing layer on 
the surface of the second recording layer of the above optical recording 
material to obtain an optical recording material. 
UTILIZABILITY IN INDUSTRY 
The DRAW type optical recording material of the present invention can be 
applied for articles with various forms and shapes such as flexible disc, 
card, tape, sheet, etc , and can be applied widely for such uses as 
mentioned below. 
(1) Monetary circulation industry cash card, credit card, prepaid card. 
(2) Medical health industry: health certificate, karte, medical card, 
emergency card. 
(3) Leisure industry: software medium, member card, entree ticket, medium 
for controlling play machine, medium for TV game, medium for orchestral 
accompaniment. 
(4) Transporting travel industry traveler's card, certificate, pass, 
passport. 
(5) Publication industry: electronic publication. 
(6) Information processing industry external memory medium for electronic 
machine, filing. 
(7) Education industry: teaching material program, result management card, 
entrance and exit management and book management of library. 
(8) Automobile industry: medium for maintenance recording, maintenance of 
running. 
(9) Fa: program recording medium for MC, NC, robbot, etc. 
(10) Others building control, home control, ID card, medium for automatic 
vending machine, cooking card, etc.