Photo-curable silicone compositions and adhesive silicone compositions

Disclosed is a curable silicone composition comprising: (A) an organopolysiloxane having a silicon-bonded unsaturated aliphatic radical; (B) an organopolysiloxane having a silicon-bonded mercaptoalkyl radical; and (C) a photoreaction-initiating amount of photoreaction initiator. The photoreaction initiator includes arylcarbonyl phosphine oxide compounds, having a radical selected from the group consisting of substituted and unsubstituted aryl radicals, and another two radicals selected from the group consisting of substituted and unsubstituted monovalent hydrocarbon radicals. The above silicone, composition is efficiently cured by visible light radiation and usable for photo-curable adhesives.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a photo-curable silicone composition which 
is hardened by being subjected to visible light radiation, and more 
particularly to a photo-curable silicone composition and an adhesive 
composition having prominent properties such as resistance to heat, cold 
and climatic conditions which are peculiar to silicone rubber, and which 
are set by means of visible light radiation, thereby contributing to the 
improvement of productivity and energy savings at the photo-setting step, 
accordingly. 
2. Description of the Prior Art 
Photo-curable silicone materials, in general, are advantageous in having 
being resistant to heat and humidity, have excellent electrical properties 
in comparison with other organic materials, and can be controlled to form 
various states such as gels, rubbers and resins. Therefore, they are 
widely utilized in a variety of commercial applications, for example, as 
coating and covering materials and adhesives for plastic substrates of low 
heat-resistance and for heat-sensitive electric and electronic parts. For 
this reason, numerous photo-curable silicone compositions and 
photo-curable silicone adhesives are suggested for the purpose of 
improving productivity and saving energy. 
For example, U.S. Pat. No. 3,726,710 by Berger et al. discloses silicone 
compositions comprising a vinyl-radical-containing organopolysiloxane 
compound and various photoreaction initiators, which are set by means of 
high intensity ultraviolet light radiation. These silicone compositions, 
however, can be cured only by ultraviolet light having a wavelength 
shorter than 300 nm, and they cannot be cured, accordingly, by radiation 
having a wavelength longer than 300 nm. Therefore, these silicone 
compositions have a defect in that, in curing, the utilization of light 
energy is low, thus requiring the photo-setting machine to be used at high 
power. 
As another prior art reference, U.S. Pat. No. 3,816,282 by Viventi 
discloses silicone compositions comprising a mercapto-radical-containing 
organopolysiloxane, polymethylvinylsiloxane and various organic peroxides. 
However, these silicone compositions must also be cured by radiation only 
in the ultraviolet range. Consequently, these silicone compositions have 
the same defect as described above. 
In addition to the two U.S. patents above, U.S. Pat. No. 4,364,809 by Satoh 
et al. discloses a silicone composition comprising a 
vinyl-radical-containing organopolysiloxane and an organic peroxide. 
However, this silicone composition also cannot be cured by radiation 
outside the ultraviolet range, and thereby gives rise to the same defect 
found for the silicone compositions described above. 
U.S. Pat. No. 4,908,395 by the applicant of the present invention suggests 
a silicone composition comprising a vinyl-radical-containing 
organopolysiloxane, an aromatic ketone photo-reaction initiator and a 
trialkenyl isocyanurate. However, as was found for the above compositions, 
this silicone composition cannot be cured by any radiation lying outside 
the ultraviolet range, and therefore has the same defect inherent in the 
compositions described above. 
SUMMARY OF THE INVENTION 
It is, therefore, an object of the present invention to provide a silicone 
composition and a silicone adhesive composition which can be cured by 
short-term exposure to visible light radiation. 
In accordance with the present invention, there is provided a curable 
silicone composition comprising: (A) an organopolysiloxane having a 
silicon-bonded unsaturated aliphatic radical; (B) an organopolysiloxane 
having a silicon-bonded mercaptoalkyl radical; and (C) a 
photoreaction-initiating amount of photoreaction initiator. The 
photoreaction initiator includes arylcarbonyl phosphine oxide compounds, 
having a radical selected from the group consisting of substituted and 
unsubstituted aryl radicals, and another two radicals selected from the 
group consisting of substituted and unsubstituted monovalent hydrocarbon 
radicals. 
The photo-curable silicone composition of the present invention can be 
cured easily by visible light radiation, thus resulting in energy savings 
and increased productivity. The photo-curable composition also retains 
prominent properties such as resistance to heat, cold and climatic 
conditions which are peculiar to silicone compounds. Therefore it is 
particularly suitable for coating and covering materials and adhesives for 
electric and electronic parts and the like. 
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The silicone composition of the present invention is based on research by 
the present inventors, in which it was found that a silicone composition 
including an organopolysiloxane having a silicon-bonded unsaturated 
aliphatic radical, an organopolysiloxane having a silicon-bonded 
mercaptoalkyl radical, and an arylcarbonyl phosphine oxide compound can be 
cured by short-term exposure to visible light radiation. In addition, 
after a silicone composition further including a 
hydrolyzable-radical-containing silicon compound was cured it was found to 
exhibit large bond strength and improved shrink-resistance, humidity 
resistance and heat resistance. 
Now, the property and compositional constituents of the photo-curable 
silicone composition according to the present invention will be described. 
First, the photo-curable silicone composition of the present invention 
comprises an organopolysiloxane (A) having a silicon-bonded unsaturated 
aliphatic radical. In the organopolysiloxane compound, the silicon-bonded 
unsaturated aliphatic radical may include a variety of olefinic and 
acetylenic radicals, for instance, vinyl, propenyl, butenyl, hexenyl, 
cyclohexenyl, cyclooctenyl, cyclohexenylethyl, cyclooctenylethyl, ethynyl, 
propynyl, butynyl and hexynyl. Among the specific radicals that may be 
mentioned, there are, for example, alkenyl radicals such as vinyl, allyl, 
3-butenyl, 5-hexenyl and the like; cycloalkenyl radicals such as 
2-cyclohexenyl, 2-cyclooctenyl, 2-(2-cyclohexenyl)ethyl, 
2-(2-cyclooctenyl)ethyl and the like; and alkynyl radicals such as 
ethynyl, 2-propynyl, 3-butynyl, 5-hexynyl and the like. Here, it is to be 
noted that, in the above silicon-bonded unsaturated aliphatic radicals, 
alkenyl radicals having an unsaturated bond at the end of the group are 
preferable, because of the reactivity of the unsaturated bond and the 
like. Moreover, considering the availability of raw materials and the 
preparation ease of the organopolysiloxane (A) by ordinary synthetic 
methods, a vinyl radical is most suitable for the silicon-bonded 
unsaturated aliphatic radicals. The number of unsaturated aliphatic 
radicals bonded to the silicon atoms is preferably within a range of about 
0.01 to about 50% relative to the total number of organic radicals 
included in the organopolysiloxane (A), for reasons of crosslinking 
efficiency in the silicone composition and heat resistance of the obtained 
photo-cured composition. In regard to the other silicon-bonded organic 
radicals in the organopolysiloxane (A), illustrative examples are, for 
example, alkyl radicals such as methyl, ethyl, propyl and the like; aryl 
radicals such as phenyl, o-tolyl, m-tolyl, p-tolyl, 2,4-xylyl and the 
like; aralkyl radicals such as 2-phenylethyl, 2-phenylpropyl and the like; 
and substituted hydrocarbon radicals such as chloromethyl, o-chlorophenyl, 
3,3,3-trifluoropropyl and the like. Here, considering the preparation ease 
of the organopolysiloxane (A) and the heat resistance of the obtained 
photo-cured composition, suitable radicals are methyl and phenyl radicals. 
The above-mentioned organopolysiloxane (A) may have any linear-chain, 
cyclic or branched structure. Of course, it is to be noted that the 
organopolysiloxane (A) can be a simple material or a mixture of two or 
more kinds of organopolysiloxane, such as those described above. Moreover, 
the organopolysiloxane may contain a hydroxyl radical or alkoxy radicals 
such as methoxy, ethoxy and the like. Preferably, an organopolysiloxane 
having a viscosity within a range of about 50 to 500,000 centipoises can 
be used in the present invention. 
Second, the photo-curable silicone composition of the present invention 
comprises an organopolysiloxane (B) having a silicon-bonded mercaptoalkyl 
radical. Among the specific mercaptoalkyl radicals that may be mentioned, 
there are, for example, mercaptomethyl, 2-mercaptoethyl, 3-mercaptopropyl, 
4-mercaptobutyl and the like. In these examples, a 3-mercaptopropyl 
radical is preferred in view of the availability of raw materials and the 
preparation ease of the organopolysiloxane. In regard to the other 
silicon-bonded organic radicals of the organopolysiloxane (B) having a 
mercaptoalkyl radical, illustrative examples are, for example, alkyl 
radicals such as methyl, ethyl, propyl and the like; cycloalkyl radicals 
such as cyclohexyl and the like; aryl radicals such as phenyl, o-tolyl, 
m-tolyl, p-tolyl, 2,4-xylyl and the like; aralkyl radicals such as 
2-phenylethyl, 2-phenylpropyl and the like; and substituted hydrocarbon 
radicals such as chloromethyl, o-chlorophenyl, 3,3,3-trifluoropropyl and 
the like. Here, it is to be noted that a methyl radical and a phenyl 
radical are preferred considering the preparation ease of the 
organopolysiloxane (B) by ordinary synthetic methods and the heat 
resistance of the obtained photo-cured composition. 
The above-mentioned organopolysiloxane (B) may have any linear-chain, 
cyclic or branched structure. Moreover, it is to be noted that the 
organopolysiloxane (B) can be a simple material or a mixture of two or 
more kinds of organopolysiloxane, such as described above. In addition, 
the organopolysiloxane may contain a hydroxyl radical or alkoxy radicals 
such as methoxy, ethoxy and the like. 
In the above organopolysiloxane (B), the number of mercaptoalkyl radicals 
bonded to the silicon atoms is preferably within a range of about 1 to 
about 50% relative to the total number of organic radicals included in the 
organopolysiloxane (B), for reasons of crosslinking efficiency in the 
silicone composition and properties of the obtained photo-cured 
composition product. 
The amount of organopolysiloxane (B) is preferably within a range of about 
1 to about 200 parts by weight relative to 100 parts by weight of 
organopolysiloxane (A). When the amount of organopolysiloxane (B) is less 
than 1 part by weight, the hardenability of the silicone composition is 
rather poor, and if it exceeds 200 parts by weight, the composition's heat 
resistance deteriorates. 
The ingredient (C), one of the characteristic components of the 
photo-curable silicone composition according to the present invention, 
works as a photoreaction initiator and is generally represented by the 
formula: 
##STR1## 
wherein R.sup.1 is selected from the group consisting of substituted and 
unsubstituted aryl radicals, and each R.sup.2 is individually selected 
from the group consisting of substituted and unsubstituted monovalent 
hydrocarbon radicals. The ingredient (C) crosslinks the organopolysiloxane 
(A) and organopolysiloxane (B) efficiently upon exposure to visible light 
radiation. Among more specific substituted and unsubstituted aryl radicals 
(R.sup.1), there are substituted and unsubstituted phenyl radicals such as 
phenyl, o-tolyl, m-tolyl, p-tolyl, 2,4,6-trimethylphenyl, 
4-isopropylphenyl, o-chlorophenyl, m-chlorophenyl, p-chlorophenyl and the 
like. In these radicals, phenyl, o-tolyl, m-tolyl, p-tolyl, 
2,4,6-trimethylphenyl and 4-isopropylphenyl are suitable for the radical 
R.sup.1 in view of the preparation ease of the ingredient (C) by ordinary 
synthetic methods. Moreover, cosidering photo-crosslinking efficiency, an 
ingredient containing a 2,4,6-trimethylphenyl radical for the radical 
R.sup.1 is more suitable. 
The substituted and unsubstituted aryl radicals may also include 
substituted and unsubstituted naphthyl radicals such as naphthyl, 
4-chloro-2-naphthyl and the like. However, these 
naphthyl-radical-containing ingredients (C) are inferior to those having a 
phenyl radical in terms of photo-crosslinking efficiency and preparation 
ease of the ingredient (C). 
Illustrative examples of substituted and unsubstituted monovalent 
hydrocarbon radicals (R.sup.2) are, for example, alkyl radicals such as 
methyl, ethyl, propyl and the like; cycloalkyl radicals such as cyclohexyl 
and the like; aryl radicals such as phenyl, o-tolyl, 2,4-xylyl and the 
like; aralkyl radicals such as 2-phenylethyl, 2-phenylpropyl and the like; 
and substituted hydrocarbon radicals such as chloromethyl, o-chlorophenyl, 
3,3,3-trifluoropropyl and the like. Here, it is to be noted that a phenyl 
radical is suitable considering the preparation ease of the 
organopolysiloxane (B) by ordinary synthetic methods and the 
photo-crosslinking efficiency of the obtained photo-curable silicone 
composition. 
The amount of ingredient (C) is preferably within a range of about 0.05 to 
about 50 parts by weight relative to 100 parts by weight of 
organopolysiloxane (A). When the amount of ingredient (C) is less than 
0.05 part by weight, the photoreaction initiating activity of ingredient 
(C) is insufficient. If the amount of ingredient (C) exceeds 50 parts by 
weight, the photoreaction initiating activity does not improve further 
despite any increase in the amount of the ingredient, and such excessive 
amounts will lead to a deterioriation in heat resistance of the 
photo-curable composition and increased shrinkage during curing. 
In the present invention, it is preferable that the photo-curable 
composition also include another photoreaction initiating agent, in 
addition to ingredient (C), at an amount of about 0.01 to about 50 parts 
by weight relative to 100 parts by weight of organopolysiloxane (A) in 
order to further improve the photo-crosslinking efficiency of the silicone 
composition. Illustrative examples of an additional photoreaction 
initiator are aromatic hydrocarbon compounds, acetophenon and its 
derivatives, xanthone and its derivatives, thioxanthone and its 
derivatives, disulfide compounds, quinone compounds, halogenated 
hydrocarbons, amines, organic peroxides and the like. Among these 
compounds, substituted and unsubstituted benzoyl-radical-containing 
compounds are preferred for the additional initiator of the present 
invention because they are stable compounds that are compatible with 
silicone compounds. Illustrative examples of these preferred initiators 
are, for example, 2-hydroxy-2-methyl-1-phenylpropane-1-on, 
2-hydroxy-2-methyl-1-(4-isopropylphenyl)propane-1-on, 
1,1-diethoxyacetophenone, t-butyl perbenzoate and the like. 
The amount of additional initiator is preferably within a range of about 
0.01 to about 50 parts by weight relative to 100 parts by weight of 
organopolysiloxane (A) for improvement of photo-crosslinking efficiency of 
the silicone composition. When the amount of additional initiator is less 
than 0.01 part by weight, the photoreaction initiating activity of the 
ingredient (C) is poor. On the other hand, when the amount exceeds 50 
parts by weight, the photoreaction initiating activity does not improve 
further despite the increase in the amount of ingredient, and such 
excessive amounts will lead to a deterioration in heat resistance of the 
photo-curable composition and increased shrinkage during curing. 
Furthermore, the photo-curable composition according to the present 
invention may include, in addition, a silicon compound (D) having a 
hydrolyzable radical, which can impart better adherence to the 
photo-curable silicone composition of the present invention. Illustrative 
examples of the hydrolyzable radical of the additional ingredient (D) are, 
for example, alkoxy radicals such as methoxy, ethoxy, propoxy and the 
like; alkenyloxy radicals such as 2-propenyloxy and the like; aryloxy 
radicals such as phenoxy and the like; acyloxy radicals such as acetoxy 
and the like; dialkyl ketoximo radicals such as methyl ethyl ketoximo and 
the like; dialkylamino radicals such as diethylamino and the like; 
acylamino radicals such as acetylamino and the like; dialkylaminoxy 
radicals such as diethylaminoxy and the like; the halogenated and 
cyanogenated radicals which are obtained respectively by halogenation or 
cyanogenation of the above mentioned radicals; halogen atoms such as 
fluoro, chloro, bromo, and iodo; and a hydroxyl radical. The partially 
hydrolyzed radicals introduced from the above-mentioned radicals also can 
be used. 
The silicon compound (D) may have other organic radicals besides the 
above-mentioned hydrolyzable radicals. Illustrative examples of those 
radicals are, for example, alkyl radicals such as methyl, ethyl, propyl 
and the like; cycloalkyl radicals such as cyclohexyl, cyclooctyl and the 
like; alkenyl radicals such as vinyl, allyl, 3-butenyl, 5-hexenyl and the 
like; cycloalkenyl radicals such as 2-cyclohexenyl, 2-cyclooctenyl and the 
like; substituted alkyl radicals such as 3-aminopropyl, 3-chloropropyl, 
3,3,3-trifluoropropyl, 2-cyanoethyl, 3-glycidyloxypropyl, 
3-acryloxypropyl, 3-methacryloxypropyl, mercaptomethyl, 3-mercaptopropyl, 
chloromethyl, N-(2-aminoethyl)-3-aminopropyl and the like; aryl radicals 
such as phenyl, o-tolyl, 2,4-xylyl, o-chlorophenyl and the like; aralkyl 
radicals such as 2-phenylethyl, 2-phenylpropyl and the like; and a 
hydrogen atom. 
Among the above-mentioned hydrolyzable radicals, alkoxy radicals and a 
hydroxyl radical are suitable for stability of the compounds and adherence 
of the silicone composition. In regard to the remaining organic radicals, 
3-aminopropyl radical, 3-mercaptopropyl radical, 3-methacryloxypropyl 
radical and vinyl radical are preferable because of their reliable 
adherence. 
According to the above, illustrative examples of the preferred silicon 
compound (D) having a hydrolyzable radical are, for example, 
(3-aminopropyl)triethoxysilane, (3-aminopropyl)trimethoxysilane, 
(3-mercaptopropyl)trimethoxysilane, (3-mercaptopropyl)triethoxysilane, 
(3-methacryloxypropyl)trimethoxysilane, 
(3-methacryloxypropyl)triethoxysilane, vinyltrimethoxysilane, 
vinyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, 
3-(trimethoxysilyl)propyl diallyl isocyanurate, 3-(triethoxysilyl)propyl 
dially isocyanurate, bis(3-(trimethoxysilyl)propyl) allyl isocyanurate, 
bis(3-(triethoxysilyl)propyl) allyl isocyanurate, 
tris(3-trimethoxysilyl)propyl) isocyanurate, 
tris(3-(triethoxysilyl)propyl) isocyanurate, and their partially 
hydrolyzed compounds. It is obvious that one or more silicon compound (D) 
can be employed in any combination. 
On the other hand, hexamethyldisilazane, 1,1,3,3-tetramethyldisilazane and 
the like are also usable in place of the hydrolyzable-radical-containing 
silicon compound (D), because these disilazane compounds produce effects 
similar to those produced by the above-mentioned silicon compounds. 
The amount of additional ingredient (D) is preferably within a range of 
about 0.1 to about 20 parts by weight relative to 100 parts by weight of 
organopolysiloxane (A). When the amount of additional ingredient (D) is 
less than 0.1 part by weight, the adhesiveness of the silicone composition 
is insufficient. On the other hand, when the amount exceeds 20 parts by 
weight, the hardenability and stability of the silicone composition 
decreases. 
Moreover, the photo-curable composition according to the present invention 
may further include, as is needed, additives such as anti-gelling agents 
(dark reaction inhibitors), heat resistance improvers, fillers, colorants 
such as pigments or dyes, solvents and the like. 
Illustrative examples of the suitable anti-gelling agents (dark reaction 
inhibitors) are, for example, hydroquinone, p-methoxyphenol, 
t-butylcatechol, phenothiazine and the like. 
Preferred examples of heat resistance improvers are phenolic compounds used 
as anti-aging agents. Illustrative examples of phenolic compounds are 
monophenol compounds such as 2,6-di-t-butyl-p-cresol, 
2-t-butyl-4-methoxyphenol, 3-t-butyl-4-methoxyphenol, 
2,6-di-t-butyl-4-ethylphenol and the like; bisphenol compounds such as 
2,2'-methylenebis(4-methyl-6-t-butylphenol), 
4,4'-thiobis(3-methyl-6-t-butylphenol), 
4,4'-butylidenebis(3-methyl-6-t-butylphenol) and the like; and 
high-molecular weight phenolic compounds such as 
1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 
1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydoroxybenzyl)benzene, 
tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate]methane, 
bis[3,3-bis(4-hydroxy-3-t-butylphenyl)butylic acid] glycol ester, 
tocopherol (vitamin E) and the like. Of course, the heat resistance 
improver is not restricted to those specifically named above. 
Fillers are utilized for the purpose of improving the mechanical strength 
of the photo-cured silicone composition and for controlling fluidity of 
the admixture. Among specific fillers which can be suitably blended to the 
silicone composition of the present invention, there are fumed silica, 
precipitated silica, fused silica, quartz fine powder and the like. These 
fillers may be blended to meet any practical use requirements. The 
preferred amount of filler is equal to or less than about 300 parts by 
weight relative to 100 parts by weight of organopolysiloxane (A). If the 
filler amount is over 300 parts by weight, the mechanical strength of the 
cured silicone composition is not further improved, and instead leads to 
difficulty in blending. 
In regard to colorants, the amount of colorant used is preferably equal to 
or less than about 300 parts by weight relative to 100 parts by weight of 
organopolysiloxane (A), in order to retain practical hardenability of the 
silicone composition. 
A solvent may be added to the silicone composition in order to decrease 
viscosity of the admixture. Illustrative examples of preferred solvents 
are, for example, aromatic hydrocarbon solvents such as toluene, xylene 
and the like, and aliphatic hydrocarbon solvents such as hexane, octane 
and the like, both of which are suitable because of their compatibility 
with organopolysiloxane compounds.

EXAMPLES 
Now, a few examples of the photo-curable silicone composition according to 
the present invention and one comparative example will be described. In 
the description of the examples, M, D, D.sup.Vi, D.sup.Ph, T.sup.SH, 
T.sup.Ph, T.sup.Vi and Q represent the following chemical formulae: 
EQU M=(CH.sub.3).sub.3 SiO.sub.1/2 
EQU D=(CH.sub.3).sub.2 SiO.sub.2/2 
EQU D.sup.Vi =CH.sub.3 (CH.sub.2 =CH)SiO.sub.2/2 
EQU D.sup.Ph =(C.sub.6 H.sub.5).sub.2 SiO.sub.2/2 
EQU T.sup.SH =HSCH.sub.2 CH.sub.2 CH.sub.2 SiO.sub.3/2 
EQU T.sup.Ph =C.sub.6 H.sub.5 -SiO.sub.3/2 
EQU T.sup.Vi =CH.sub.2 =CH-SiO.sub.3/2 
EQU Q=SiO.sub.4/2 
EXAMPLE 1 
First, 60 parts by weight of a dimetylvinylsilylterminated 
polymethylphenylsiloxane consisting essentially of 95 mole percent of 
dimethylsiloxy units (D) and 5 mole percent of diphenylsiloxy units 
(D.sup.Ph) and having a viscosity of 1,000 centipoises at 25.degree. C. 
was put into a flask and mixed with 80 parts by weight of a toluene 
solution containing 50 percent by weight of a polymethylvinylsiloxane 
represented by an average rational formula M.sub.6 D.sup.Vi Q.sub.8 and 
having a melting point of 100.degree. C. Next, the mixture was heated at a 
reduced pressure of 20 mmHg until the toluene was completely removed and 
the temperature of the mixture had reached 150.degree. C. Then, 100 parts 
by weight of the residual mixture was added to a mixture previously 
prepared from 40 parts by weight of a mercaptopropyl-radical-containing 
polymethylsiloxane, having an average rational formula represented by 
MT.sup.SH.sub.5 D.sub.60 and a viscosity of 200 centipoises at 25.degree. 
C., 2 parts by weight of 2-hydroxy-2-methyl-1-phenylpropane-1-on and 0.5 
part by weight of 2,4,6-trimethylbezoyl diphenyl phosphine oxide, thereby 
obtaining the silicone composition of Example 1. 
Next, a glass plate having a dimensions of 50 mm.times.50 mm was coated 
with the silicone composition and covered with another glass plate having 
the same dimensions. The glass-coating composition was then exposed to the 
glow light of a 60-watt incandescent electric lamp at a distance of 5 cm 
from the lamp. At this time, the light intensity values were 0.200 
mW/cm.sup.2 at a wavelength of 420 nm and 0.001 mW/cm.sup.2 at a 
wavelength of 365 nm. These light intensity values show that the 
incandescent lamp gave off visible light radiation at a wavelength of over 
300 nm. After exposing the glass-coating composition for two minutes under 
this condition, the glass plates became fixed to one other, thereby 
establishing a silicone composition hardened by visible light radiation at 
a wavelength of over 300 nm. The integrated amount of light measured by an 
integrating photometer at this time as 24 mJ/cm.sup.2 at a wavelength of 
420 nm. 
The above-obtained silicone composition was poured into a cup made of 
polystyrene and having a depth of 3 cm, and it was exposed to the 
above-described light radiation condition. When the integrated amount of 
light measured by an integrating photometer reached a value of 200 
mJ/cm.sup.2, the silicone composition had hardened to a depth of 12 mm. 
In another experiment, the above-obtained silicone composition was poured 
into a mold having a dimensions of 15 cm.times.15 cm and a depth of 1 mm. 
The mold was set on a conveyer belt which moved at a transporting speed of 
2 m/min and passed under a 80 W/cm high-pressure mercury vapour lamp 
radiating at a height of 10 cm from the conveyer belt. In passing through 
the light radiation, the silicone composition in the mold was cured to 
form a sheet having a thickness of 1 mm. This sheet was then measured for 
various properties using a method in accordance with Japan Industrial 
Standard (JIS) No. K6301 and was determined to have a hardness of 40, a 
tensile strength of 12 kgf/cm.sup.2 and an elongation of 100%. 
EXAMPLE 2 
First, 100 parts by weight of a dimetylvinylsilylterminated 
polymethylvinylsiloxane, consisting essentially of 98 mole percent of 
dimethylsiloxy units (D) and 2 mole percent of methylvinylsiloxy units 
(D.sup.Vi) and having a viscosity of 20,000 centipoises at 25.degree. C., 
was placed in a universal kneader and mixed with 20 parts by weight of a 
trimethylsilyl-terminated mercaptopropyl-radical-containing 
polydimethylsiloxane, consisting essentially of 20 mole percent of 
methyl(3-mercaptopropyl)siloxy units with the rest being dimethylsiloxy 
units (D) and having a viscosity of 400 centipoises at 25.degree. C., 1 
part by weight of 2-hydroxy-2-methyl-1-(4-isopropylphenyl)propane-1-on and 
0.15 part by weight of 2,4,6-trimethylbenzoyl diphenyl phosphine oxide. 
Next, 15 parts by weight of fumed silica having a specific surface of 200 
m.sup.2 /g and being surface-treated with a siloxane was added to the 
above-obtained mixture until it became dispersed uniformly by stirring. 
This composition was further milled with a three-roll mill to produce a 
uniform formulation. This formulation had a consistency of 250 with a 1/4 
cone in accordance with ASTM standards. 
The formulation was put in a 50 ml beaker and placed in a bell jar in order 
to deaerate under reduced pressure. After deaeration, the formulation was 
left to stand outdoors in direct sunlight. After 10 minutes of sunlight 
exposure, the formulation had hardened into a rubber-like state to a depth 
of 18 mm. 
In another experiment, the formulation was poured into a mold having 
dimensions of 15 cm.times.15 cm and a depth of 1 mm. The formulation in 
the mold was left to stand outdoors in direct sunlight, and 10 minutes 
later it had cured to form a sheet having a thickness of 1 mm. This sheet 
was then measured for various properties using a method in accordance with 
Japan Industrial Standard No. K6301 and was determined to have a hardness 
of 56, a tensile strength of 19 kgf/cm.sup.2 and an elongation of 90%. 
EXAMPLE 3 
First, 100 parts by weight of a toluene solution containing 50 percent by 
weight of a vinyl-radical-containing polyphenylmethylsiloxane represented 
by an average rational formula T.sup.ph.sub.4 T.sup.Vi D.sub.4 and having 
a melting range of 40.degree. to 60.degree. C., was mixed with 100 parts 
by weight of a toluene solution containing 50 percent by weight of a 
mercaptopropy-radical-containing polyphenylmethylsiloxane, represented by 
an average rational formula T.sup.ph.sub.4 T.sup.SH D.sub.2 and having a 
melting range of 80.degree. to 120.degree. C., and 5 parts by weight of 
2,4,6-trimethylbenzoyl diphenyl phosphine oxide. The obtained silicone 
mixture was a colorless and clear solution having a viscosity of 20 
centipoises at 25.degree. C. 
Next, 2 ml of the above-obtained silicone solution was dropped on a silicon 
wafer having a diameter of 5 inches, after which the wafer was rotated at 
a speed of 500 rpm for 10 seconds, and then at a speed of 2,000 rpm for 2 
minutes by a spinner, thereby coating the wafer with the silicone 
solution. Next, the wafer was heated on a hot plate at a temperature of 
100.degree. C. for one minute to volatilize the solvent completely. At 
this time, the silicone coating was measured to have a thickness of 3 
.mu.m. A half portion of the silicone-coated silicon wafer was shaded with 
an aluminum plate, and the other half was exposed to the glow light of a 
60-watt incandescent electric lamp at a distance of 5 cm from the lamp. At 
this time, the light intensity values were 0.200 mW/cm.sup.2 at a 
wavelength of 420 nm and 0.001 mW/cm.sup.2 at a wavelength of 365 nm. The 
glow light exposure was continued for two minutes, and the integrated 
amount of light measured by an integrating photometer at this time was 24 
mJ/cm.sup.2 at a wavelength of 420 nm. Next, the silicon wafer was steeped 
in toluene for 10 minutes. Then the silicon wafer was removed from the 
toluene, only the half portion of silicone coating that was exposed to the 
glow light remained on the silicon wafer. After drying, the silicone 
coating was subjected to a pencil hardness test, the result of which was a 
2B level. 
EXAMPLE 4 
First, 100 parts by weight of a trimetylsilylterminated 
polymethylvinylsiloxane, consisting essentially of 99.8 mole percent of 
dimethylsiloxy units (D) and 0.2 mole percent of methylvinylsiloxy units 
(D.sup.Vi) and having an average polymerization degree of 6,000, and 4 
parts by weight of a hydroxy-terminated polydimethylsiloxane, having a 
viscosity of 30 centipoises at 25.degree. C., were placed in a dough mixer 
and mixed thoroughly. Then, 55 parts by weight of fumed silica divided 
into several portions, having a specific surface of 200 m.sup.2 /g and 
being surface-treated with a siloxane, was added to the above-obtained 
mixture and dispersed uniformly by stirring. After being heated to a 
temperature of 150.degree. C., the mixture was kneaded for 2 hours, 
thereby obtaining a base formulation. This formulation was applied to 
milling rolls in a mill and was blended with 3 parts by weight of a 
mercaptopropyl-radical-containing polydimethylsiloxane, represented by an 
average rational formula T.sup.SH.sub.5 D.sub.60 and having a viscosity of 
2,000 centipoises at 25.degree. C., 2 parts by weight of 
2-hydroxy-2-methyl-1-phenylpropane-1-on and 0.4 part by weight of 
2,4,6-trimethylbezoyl diphenyl phosphine oxide in order to prepare a 
sample composition. The sample composition had a William's plasticity of 
300 at a temperature of 25.degree. C. With this sample composition, a core 
wire having a diameter of 1 mm was coated to have an outside diameter of 3 
mm, using an extruding machine. The coated wire was left to stand outdoors 
in direct sunlight for 1 hour, and, as a result, the coating composition 
had hardened completely. 
In another experiment, the same sample composition was rolled with a 
calendering roll to prepare a sheet having a thickness of 1 mm. This sheet 
was left to stand outdoors in direct sunlight for 1 hour in conditions 
similar to those mentioned above, resulting in a cured sheet having a 
thickness of 1 mm. This cured sheet was then measured for various 
properties using a method in accordance with Japan Industrial Standard No. 
K6301, and was determined to have a hardness of 60, a tensile strength of 
100 kgf/cm.sup.2, an elongation of 400% and a tear strength (JIS B type) 
of 48 kgf/cm.sup.2. 
EXAMPLE 5 
First, 100 parts by weight of the silicone composition of Example 1 and 50 
parts by weight of acetylene black were placed in a universal kneader and 
stirred until uniformly dispersed. This composition was further milled 
with a three-roll mill to have a uniform formulation. 
This formulation was coated on a aluminum plate having dimensions of 500 
mm.times.150 mm and a thickness of 0.3 mm, using a roll coating applicator 
which is regulated to a coating thickness of 300 .mu.m. Then, the coated 
aluminum plate was left to stand outdoors in direct sunlight for 4 hours 
in conditions similar to those mentioned above in order to have a coating 
cured in a rubbery condition. At this time, the coating had a thickness of 
180 .mu.m, and measurements revealed that this cured coating had a 
specific volume resistance of 30 .OMEGA..cm. 
EXAMPLE 6 
First, 100 parts by weight of a dimethylvinylsilyl-terminated 
polymethylphenylsiloxane, consisting essentially of 95 mole percent of 
dimethylsiloxy units (D) and 5 mole percent of diphenylsiloxy units 
(D.sup.Ph) and having a viscosity of 1,000 centipoises at 25.degree. C., 
was mixed with 12 parts by weight of a mercaptopropyl-radical-containing 
polymethylsiloxane, having an average rational formula represented by 
MT.sup.SH.sub.5 D.sub.60 and a viscosity of 300 centipoises at 25.degree. 
C., and a solution prepared from 0.01 part by weight of p-methoxyphenol 
and 0.5 part by weight of toluene. To this mixture was further added a 
mixed solution of 2.0 parts by weight of 2-hydroxy-2-methylpropiophenone 
and 0.5 part by weight of 2,4,6-trimethylbezoyl diphenyl phosphine oxide. 
After uniform mixing, a base composition was obtained. 
Next, 115 parts by weight of the above base composition was added with 1 
part by weight of (3-methacryloxypropyl)trimethoxysilane for the 
hydrolyzable-radical-containing silicon compound, as shown in Table 1, and 
was mixed uniformly to obtain the composition of sample No. 1 in Table 1. 
In a similarly manner, by substituting the hydrolyzable-radical-containing 
silicon compound with other compounds shown in Table 1, respective 
silicone composition sample Nos. 2 to 5 were prepared. 
On the other hand, composition sample No. 6, which contains no 
hydrolyzable-radical-containing silicon compound, and composition sample 
No. 7, which contains no 2,4,6-trimethylbenzoyl diphenyl phosphine oxide, 
were prepared for comparison in the same manner as shown in Table 1. In 
addition, 100 parts by weight of a trimethylsilyl-terminated 
organopolysiloxane, consisting essentially of 10 mole percent of 
methylvinylsiloxy units (D.sup.vi) with the rest being dimethylsiloxy 
units (D) and having a viscosity of 3,000 centipoises at 25.degree. C., 
was added to 2 parts by weight of 2-hydroxy-2-methylpropiophenone and 0.5 
part by weight of triallyl isocyanurate and uniformly mixed, thereby 
obtaining another comparative composition, composition sample No. 8, which 
is also shown in Table 1. 
Each of the above-obtained composition sample Nos. 1 to 8 was held at a 
composition thickness of 200 .mu.m between a pair of glass plates each 
having dimensions of 25 mm.times.80 mm.times.2 mm in such a way that the 
glass plates overlap with each other over an area of 25 mm.times.20 mm. 
Each of the sample pieces of coupled glass plates with the sample 
compositions was exposed to the glow light of a 60-watt incandescent 
electric lamp at a distance of 5 cm from the lamp. At this time, the light 
intensity values were 0.200 mW/cm.sup.2 at a wavelength of 420 nm and 
0.001 mW/cm.sup.2 at a wavelength of 365 nm. The glow light exposure was 
continued for ten minutes under these conditions, and the integrated 
amount of light measured by an integrating photometer at this time was 120 
mJ/cm.sup.2 at a wavelength of 420 nm. For each of the sample Nos. 1 to 6, 
the coupled glass plates were firmly fixed to each other by the 
composition, thus demonstrating that each of the silicone compositions 
were cured by visible light radiation. For example Nos. 7 and 8, each 
sample piece was exposed to the glow light for another hour under the same 
conditions as the above, but neither of them showed any hardening at all. 
Each of the photo-exposed sample pieces obtained above was subjected to a 
shear adhesion test, the results of which are shown in Table 1. 
Moreover, with respect to sample Nos. 1 to 5, each cured sample piece was 
subjected to a thermal cycle test, wherein the sample piece was cyclically 
cooled to -40.degree. C. for 30 minutes and then heated to 80.degree. C. 
for 30 minutes. This cycle was repeated 100 times. After the thermal cycle 
test, each sample piece was measured with respect to its crack initiation, 
adhesion strength under shear and cohesive failure rate, the results of 
which are shown in Table 2. In this description, a cohesive failure rate 
denotes a rate at which sample pieces are split apart by cohesive failure 
and not by joint failure under enough tensile force. 
In another experiment, each of the photo-cured sample pieces was subjected 
to a humidity resistance test, wherein the sample piece was subjected to a 
temperature of 85.degree. C. and a relative humidity of 95% for 1,000 
hours. Each of the photo-cured sample pieces was also subjected to heat 
tests, in which all the sample pieces were subjected to a temperature of 
150.degree. C. for 24 hours, and 200.degree. C. for 24 hours, 
respectively. The results of the humidity resistance test and the heat 
tests are shown in Table 2. 
For an adhesion test, 0.5 g of the composition of sample No. 1 was applied 
to a glass plate having a dimensions of 50 mm.times.50 mm.times.1 mm, and 
covered with another glass plate having the same dimensions, while making 
sure to avoid trapping any air bubbles in the composition. The glass 
plates, with a spacer, were pressed so that the distance between the glass 
plates was held constant to make the adhesive composition form uniform 
layer having a thickness of 0.1 mm, thereby obtaining a sample piece. This 
sample piece was then exposed to the glow light of a 60-watt incandescent 
electric lamp at a distance of 5 cm from the lamp through a cover glass. 
The glow light exposure was continued until the adhesive composition 
hardened, and at this time the integrated amount of light was measured by 
an integrating photometer to be 50 mJ/cm.sup.2 at a wavelength of 420 nm. 
The above photo-cured sample piece was then subjected to mechanical peeling 
of the glass plates. The cohesive failure rate at this time was 100%. 
Moreover, using Japan Industrial Standard No. K6850, the composition of 
sample No. 1 had been formed into an adhesive composition layer having a 
thickness of 0.1 mm between glass plates having dimensions in accordance 
with Standard No. K6850 and 0.1 mm thick. For hardening, the adhesive 
composition layer was exposed to glow light under the same light radiation 
condition of 190 mJ/cm.sup.2. The obtained photo-cured composition was 
then measured to have a shear adhesion strength of 2.8 kgf/cm.sup.2 and a 
cohesive failure rate of 100%. 
EXAMPLE 7 
First, 60 parts by weight of a dimethylvinylsilyl-terminated 
polymethylvinylsiloxane, consisting essentially of the rest being 
dimethylsiloxy units (D) and having a viscosity of 3,000 centipoises at 
25.degree. C., and 40 parts by weight of polymethylvinylsiloxane 
represented by an average rational formula M.sub.5.5 D.sup.Vi Q.sub.12 and 
having a melting point of 100.degree. C., were placed in a universal 
kneader and dispersed uniformly by stirring while being heated. After 
cooling, 15 parts by weight of fumed silica, having a specific surface of 
200 m.sup.2 /g and being surface-treated with a siloxane, was added to the 
mixture and uniformly dispersed therein. This mixture was kneaded while 
being heated at a temperature of 150.degree. C. at a reduced pressure of 
10 mmHg for 4 hours. The mixture was cooled and then 30 parts by weight of 
a trimethylsilyl-terminated mercaptopropyl-radical-containing 
organopolysiloxane, consisting of 20 mole percent of methyl 
(3-mercaptopropyl)siloxy units with the rest being dimethylsiloxy units 
(D) and having a viscosity of 400 centipoises at 25.degree. C., was added 
and mixed uniformly therein. After that, to the obtained mixture was 
further added a solution which was prepared, in advance, from 2.5 parts by 
weight of 2-hydroxy-2-methyl-1-phenylpropane-1-on for a photo-reaction 
initiator, 0.5 part by weight of 2,4,6-trimethylbezoyl diphenyl phosphine 
oxide, 0.1 part by weight of p-methoxy phenol and 0.05 part by weight of 
p-t-butylpyrocatechol as polymerization inhibitors, and 0.2 part by weight 
of tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane as an 
anti-oxidant, and mixed uniformly. To the above-obtained composition, 1.3 
parts by weight of (3-metacryloxypropyl)trimethoxysilane, 1.3 parts by 
weight of (3-aminopropyl)trimethoxysilane and 0.5 parts by weight of 
tris(3-(trimethoxysilyl)propyl) isocyanurate were added and stirred in 
uniformly. This composition had a consistency of 230 with a 1/4 cone in 
accordance with ASTM standards. 
The above-obtained composition was divided into several portions, and each 
portion was held at a composition thickness of 5 mm between each pair of 
adherends, each adherend having dimensions of 10 mm.times.70 mm and a 
thickness of 2 mm, and being made of a material shown in Table 3, 
respectively. The adherends were placed so as to overlap with each other 
over an area of 10 mm.times.20 mm, thereby preparing a test piece. Each of 
the test pieces was left to stand outdoors for 4 hours, and were exposed 
to direct sunlight by being placed upright on a polytetrafluoroethylene 
sheet. After the exposure, all the compositions had hardened completely. 
Each of the photo-cured test pieces was then measured for adhesion 
strength under shear stress, and the results are shown in Table 3. 
EXAMPLE 8 
First, 100 parts by weight of a dimetylvinylsilyl-terminated 
organopolysiloxane, consisting essentially of 5 mole percent of 
methylvinylsiloxy units (D.sup.vi), 30 mole percent of 
dimethylphenylsiloxy units and dimethylsiloxy units (D) and having a 
viscosity of 1,500 centipoises at 25.degree. C., and 50 parts by weight of 
a toluene solution containing 50 percent by weight of an 
organopolysiloxane, represented by an average rational formula T.sup.SH 
T.sup.Ph.sub.3 D.sup.Ph.sub.2 D.sub.4 and having a melting range of 
40.degree. to 60.degree. C., were placed in a flask and stirred while 
being heated at a reduced pressure of 10 mmHg, in order to thoroughly 
remove the toluene, until the temperature of the mixture finally reached a 
temperature of 160.degree. C. The obtained composition was then mixed with 
1.5 parts by weight of (3-methacryloxypropyl)trimethoxysilane, 1.0 part by 
weight of (3-aminopropyl)trimethoxysilane and 3 parts by weight of 
2,4,6-trimethylbezoyl diphenyl phosphine oxide and heated at a temperature 
of 100.degree. C. for 1 hour, thereby obtaining a clear composition. 
In a similar manner to that in Example 6, the composition was subjected to 
an adhesion test using various base plates made of glass and the like, the 
results of which are shown in Table 4. In this test, a sample piece was 
exposed to visible light radiation through a cover glass. 
EXAMPLE 9 
First, 80 parts by weight of a dimethylvinylsilyl-terminated 
polymethylphenylsiloxane, consisting essentially of 95 mole percent of 
dimethylsiloxy units (D) and 5 mole percent of diphenylsiloxy units 
(D.sup.Ph) and having a viscosity of 3,000 centipoises at 25.degree. C., 
and 40 parts by weight of a toluene solution containing 50 percent by 
weight of polymethylvinylsiloxane, represented by an average rational 
formula M.sub.6 D.sup.Vi Q.sub.8 and having a melting point of 100.degree. 
C., were placed in a flask and stirred while being heated at a reduced 
pressure of 10 mmHg, in order to thoroughly remove the toluene. Next, 100 
parts by weight of this mixture of vinyl-radical-containing polysiloxane 
was placed in a universal kneader and mixed with 10 parts by weight of 
fumed silica surface-treated with a siloxane and dispersed uniformly. 
Next, the mixture was kneaded while being heated at a temperature of 
150.degree. C. at a reduced pressure of 10 mmHg for 2 hours. After 
cooling, the mixture was first mixed with 30 parts by weight of a 
mercaptopropyl-radical-containing polysiloxane, 1.5 parts by weight of 
2-hydroxy-2-methylpropiophenone and 0.5 part by weight of 
2,4,6-trimethylbezoyl diphenyl phosphine oxide, and was then mixed with 2 
parts by weight of (3-methacryloxypropyl)trimethoxysilane, 2 parts by 
weight of (3-aminopropyl)trimethoxysilane and 0.5 part by weight of 
tris(3-(trimethoxysilyl)propyl) isocyanurate until uniformly mixed. The 
resulting composition had a consistency of 260 with a 1/2 cone in 
accordance with ASTM standards. This composition was further dispersed 
with 2 parts by weight of rutile titanium dioxide using a three-roll mill, 
thereby producing a white-colored formulation. 
In a similar manner to that in Example 6, the composition was held between 
glass plates to form a test piece, and was photo-cured. In this example, 
the test piece had a shear adhesion strength of 28 kgf/cm.sup.2 and a 
cohesive failure rate of 100%. 
COMATIVE EXAMPLE 1 
The procedure of Example 1 was repeated except that 2,4,6-trimethylbenzoyl 
diphenyl phosphine oxide was not employed in order to obtain a 
glass-coating composition that could be compared with Example 1. 
In the same manner as in Example 1, the glass-coating composition was 
exposed to glow light for thirty minutes. However, the glass-coating 
composition remained in a liquid state, thereby demonstrating that without 
2,4,6-trimethylbenzoyl diphenylphosphine oxide the glass-coating 
composition would be left uncured by visible light. 
As is clearly shown in the above examples and the comparative example, 
according to the combination of an organopolysiloxane having a 
silicon-bonded unsaturated aliphatic radical, an organopolysiloxane having 
a silicon-bonded mercaptoalkyl radical and an arylcarbonyl compound as a 
photoreaction initiator, the silicone composition of the present invention 
can be easily cured by short-term exposure to visible light radiation, and 
can therefore be utilized efficiently as a photo-cured adhesive 
composition. 
Besides, a silicone composition comprising a vinyl-radical-containing 
organopolysiloxane, a mercapto-radical-containing organopolysiloxane, 
either a hydrolyzable-radical-containing silicon compound or an alkenyl 
isocyanurate or its derivative and a photo-reaction initiator such as a 
benzophenone can be cured by radiation in the ultraviolet range, though it 
is not cured by visible light radiation. 
As many apparently widely different embodiments of the present invention 
may be made without departing from the spirit and scope thereof, it is to 
be understood that the invention is not limited to the specific 
embodiments thereof, except as defined in the appended claims. 
TABLE 1 
__________________________________________________________________________ 
Sample No. 
Ingredients 1 2 3 4 5 6 7 8 
__________________________________________________________________________ 
polymethylphenylvinylsiloxane 
100 
100 
100 
100 
100 
100 
100 100 
mercaptopropyl-radical-containing 
12 
12 
12 
12 
12 
12 
12 -- 
polymethylvinylsiloxane 
(3-methacryloxypropyl)trimethoxysilane 
1 -- 
-- 
-- 
-- 
-- 
-- -- 
(3-aminopropyl)triethoxysilane 
-- 
1 -- 
-- 
-- 
-- 
-- -- 
vinyltrimethoxysilane 
-- 
-- 
1 -- 
-- 
-- 
-- -- 
(3-mercaptopropyl)trimethoxysilane 
-- 
-- 
-- 
1 -- 
-- 
-- -- 
3-(trimethoxysilyl)propyl diallyl 
-- 
-- 
-- 
-- 
1 -- 
-- 0.5 
isocyanurate 
2-hydroxy-2-methylpropiophenone 
2.0 
2.0 
2.0 
2.0 
2.0 
2.0 
2.0 
2.0 
2,4,6-trimethylbenzoyl diphenyl 
0.5 
0.5 
0.5 
0.5 
0.5 
0.5 
-- -- 
phosphine oxide 
Adhesiveness 
Cohesive Failure Rate 
100 
80.sup.2) 
100 
80.sup.2) 
100 
0 not not 
(%) cured 
cured 
Shear Adhesion Strength 
3.0 
2.5 
2.8 
2.9 
2.4 
--.sup.1) 
(kgf/cm.sup.2) 
__________________________________________________________________________ 
Notes 
.sup.1) The sample peeled off when being set on the holder of the tester, 
thus no measurable data could be obtained. 
.sup.2) After one day, both samples were remeasured to have a value of 
100%, respectively. 
TABLE 2 
__________________________________________________________________________ 
Sample No. 
1 2 3 4 5 
__________________________________________________________________________ 
Thermal Cycling 
Cracking no no no no no 
Test Shear Adhesion Strength 
2.6 2.9 3.2 2.7 2.8 
(kgf/cm.sup.2) 
Cohesive Failure Rate 
100 100 100 100 100 
(%) 
Humidity Cracking no no no no no 
Resistance Test 
Shear Adhesion Strength 
2.9 2.6 3.0 3.2 2.9 
(kgf/cm.sup.2) 
Cohesive Failure Rate 
100 100 100 100 100 
(%) 
Heat 
at Cracking no no no no no 
Test 
150.degree. C. 
Shear Adhesion Strength 
3.2 3.4 3.1 3.0 2.6 
for (kgf/cm.sup.2) 
24 hrs 
Cohesive Failure Rate 
100 100 100 100 100 
(%) 
at Cracking no no no no no 
200.degree. C. 
Shear Adhesion Strength 
3.8 3.8 3.0 2.8 3.8 
for (kgf/cm.sup.2) 
24 hrs 
Cohesive Failure Rate 
100 100 100 100 100 
(%) 
__________________________________________________________________________ 
TABLE 3 
______________________________________ 
Adhesiveness 
Shear Adhesion 
Cohesive Failure 
Adherend Materials 
Strength (kgf/cm.sup.2) 
Rate*.sup.) 
______________________________________ 
Glass 18 A 
Aluminum 15 A 
Brass 13 A 
Stainless Steel 
14 A 
(SUS 304 of JIS) 
Cold Rolled Steel 
15 A 
(in JIS G3141) 
Copper 17 A 
ABS Resin 13 B 
Unsaturated 16 A 
Polyester/Glass 
Epoxy Resin/Glass 
20 A 
Phenol Resin 13 A 
Polycarbonate 
14 A 
______________________________________ 
Note: 
*.sup.) Mark A indicates that the cohesive failure rate was 100%. 
Mark B indicates that the cohesive failure rate was between 80% and 100%. 
TABLE 4 
______________________________________ 
Plate Materials 
Adhesiveness 
Adhered to Glass 
Shear Adhesion 
Cohesive Failure 
Plate Strength (kgf/cm.sup.2) 
Rate (%) 
______________________________________ 
Glass 3.2 100 
Aluminum 2.3 100 
Brass 2.1 80 
Stainless Steel 
2.6 100 
(SUS 304 of JIS) 
Copper 3.0 100 
Nickel 2.3 80 
ABS Resin 2.4 80 
Epoxy Resin 3.4 100 
Unsaturated 3.0 100 
Polyester/Glass 
(20% Glass Fiber) 
Phenol Resin 2.7 100 
Polycarbonate 
2.6 100 
PBT resin/Glass 
2.4 100 
(20% Glass Fiber) 
______________________________________