Source: https://patents.justia.com/patent/5646089
Timestamp: 2019-10-22 05:47:51
Document Index: 612867285

Matched Legal Cases: ['arts\n89', 'arts\n10', 'arts\n60', 'arts\n10', 'arts\n3', 'arts\n4', 'arts\n89']

US Patent for Heat transfer cover films Patent (Patent # 5,646,089 issued July 8, 1997) - Justia Patents Search
Justia Patents Having Plural Interactive LeavesUS Patent for Heat transfer cover films Patent (Patent # 5,646,089)
May 26, 1995 - Dai Nippon Insatsu Kabushiki Kaisha
The fourth aspect of this invention concerns a heat transfer cover film including a substrate film having a transparent resin layer releasably formed thereon, said resin layer being further provided on its surface with a heat-sensitive adhesive layer, characterized in that said heat-sensitive adhesive layer is made of a resin having a glass transition temperature or Tg lying between 40.degree. C. and 75.degree. C.
By constructing from a resin with a Tg of 40.degree.-75.degree. C. a heat-sensitive adhesive layer provided on the surface of a transparent resin layer, the transparent resin layer can be well transferred onto an image through a thermal head while it is kept in good "foil cutting" condition. Thus the transparent resin layer is so easily transferred on the image by the heat of the thermal head that an image representation improved in terms of such properties as durability, esp. rub resistance, chemical resistance and solvent resistance can be obtained expeditiously.
The substrate film 1 may vary in thickness to have proper strength, heat resistance, etc., but should preferably have a thickness ranging generally from 3 .mu.m to 100 .mu.m.
The radically polymerizable monomers, for instance, may include (meth)acrylic ester, (meth)acrylamide, allyl compounds, vinyl ethers, vinyl esters, vinyl cyclic compounds, N-vinyl compounds, styrene, (meth)acrylic acid, crotonic acid and itaconic acid. The polyfunctional monomers, for instance, subsume diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tris-(.beta.-(meth)acryloxyethyl)isocyanurate.
In the 1st aspect of this invention, suitable solvents, non-reactive transparent resins or the like, if required, may be added to the ionizing radiation-curable resin comprising the above-mentioned components to prepare ink whose viscosity, etc. are regulated. This ink is then coated on the substrate film by numerous means such as gravure coating, gravure reverse coating or roll coating. Subsequent drying and curing gives the ionizing radiation-cured resin layer 2, which has preferably a thickness of about 0.5 .mu.m to about 20 .mu.m.
When forming the aforesaid ionizing radiation-cured resin layer, it is desired that a relatively large amount of particles of high transparency be added to said cured resin layer. These particles may embrace such inorganic particles as silica, alumina, calcium carbonate, talc or clay particles or such organic particles such as acrylic, polyester, melamine or epoxy resin particles, all being divided to as fine as submicrons or a few .mu.m. Preferably, such particles of high transparency are used in an amount ranging from 10 to 200 parts by weight per 100 parts by weight of the ionizing radiation-curable resin. In too small amounts insufficient "film cutting" can take place during heat transfer, whereas in too large amounts the protective layer is lacking in transparency. Various images to be covered may be further improved in terms of such properties as slip properties, gloss, light fastness, weather resistance and whiteness by incorporation of other additives, e.g. waxes, slip agents, UV absorbers, antioxidants and/or fluorescent brighteners.
When the heat transfer film used in this invention is particularly made of a polyester film made easily bondable, a water soluble polymer is used as the release layer. As such a water soluble polymer, use is preferably made of polyvinyl alcohol, polyvinyl pyrrolidone, gelatin, carboxymethylcellulose, methylcellulose, polyethylene oxide, gum arabic, water soluble butyral, water soluble polyester, water soluble polyurethane, water soluble polyacrylic and water soluble polyamide, which may be used in combination of two or more to control releasability. The release layer may then have a thickness of about 0.01 .mu.m to about 5 .mu.m.
In order to make these layers more transferable, a heat-sensitive adhesive layer 5 may be additionally provided on the surface of the ionizing radiation-cured resin layer. Such an adhesive layer, for instance, may be formed by coating on that surface resins of improved hot adhesiveness such as acrylic resin, vinyl chloride resin, vinyl chloride/vinyl acetate copolymer resin and polyester resin, followed by drying, and may preferably have a thickness of about 0.5 .mu.m to about 10 .mu.m.
The transparent resin layer 2 may be formed on the substrate film 1 or the release layer 3 which has been formed on it by coating thereon an ink preparation comprising the above-mentioned resin and wax by numerous means such as gravure coating, gravure reverse coating or roll coating, followed by drying. If the transparent resin layer is made of a mixed resin/wax dispersion, then it is preferable to carry out drying at a temperature lower than the melting point of the resin particles, e.g. a relatively low temperature lying in the range of about 50.degree. C. to about 100.degree. C. Because drying at such a temperature gives a coat containing some resin particles, the "film cutting" at the time of heat transfer is improved so significantly that the slip properties of the transfer film can be retained.
Prior to forming the aforesaid transparent resin layer, it is preferred to provide the release layer 3 on the surface of the substrate film. Such a release layer is made of such releasants as waxes, silicone wax, silicone resin, fluorocarbon resin and acrylic resin. The release layer 3 may be formed in similar manners as applied for forming the transparent resin layer, and may have a thickness of about 0.5 .mu.m to about 5 .mu.m. When it is desired to obtain a matted protective layer after transfer, various particles may be incorporated in the release layer. Alternatively, use may be made of a substrate film matted on its surface on which the release layer is to be provided.
When the heat transfer film used in this invention is particularly made of a polyester film rendered easily bondable, a water soluble polymer is used as the release layer. As such a water soluble polymer, use is preferably made of polyvinyl alcohol, polyvinyl pyrrolidone, gelatin, carboxymethylcellulose, methylcellulose, polyethylene oxide, gum arabic, water soluble butyral, water soluble polyester, water soluble polyurethane, water soluble polyacrylic and water soluble polyamide, which may be used in combination of two or more to control releasability. The release layer may then have a thickness of about 0.01 .mu.m to about 5 .mu.m.
In order to make these layers more transferable, a heat-sensitive adhesive layer 5 may be additionally provided on the surface of the transparent resin layer. Such an adhesive layer, for instance, may be formed by coating on that surface resins of improved hot adhesiveness such as acrylic resin, vinyl chloride resin, vinyl chloride/vinyl acetate copolymer resin and polyester resin, followed by drying, and may have a thickness of about 0.5 .mu.m to about 10 .mu.m.
The transparent resin layer 2 may be formed on the substrate film 1 or the release layer 3 which has been formed on it by coating thereon an ink preparation comprising the above-mentioned resin and wax by numerous means such as gravure coating, gravure reverse coating or roll coating, followed by drying. That layer 2 may preferably have a thickness of about 0.1 .mu.m to about 20 .mu.m.
Prior to forming the transparent resin layer, it is preferred to provide the release layer 3 on the surface of the substrate film. Such a release layer is made of a releasant such as waxes, silicone wax, silicone resin, fluorocarbon resin and acrylic resin. The release layer 3 may be formed in similar manners as applied for forming the above-mentioned transparent resin layer, and may have a thickness of about 0.5 .mu.m to about 5 .mu.m. When it is desired to obtain a matted protective layer after transfer, various particles may be incorporated in the release layer. Alternatively, use may be made of a substrate film matted on its surface on which the release layer is to be provided.
In order to make these layers more transferable, a heat-sensitive adhesive layer 5 may be additionally provided on the surface of the transparent resin layer. Such an adhesive layer, for instance, may be formed by coating on that surface resins of improved hot adhesiveness such as acrylic resin, vinyl chloride resin, vinyl chloride/vinyl acetate copolymer resin and polyester resin, followed by drying, and may have a thickness of about 0.1 .mu.m to about 10 .mu.m.
The transparent resin layer 2 may be formed on the substrate film 1 or the release layer 3 which has been formed on it by coating thereon an ink preparation comprising the above-mentioned resin and wax by numerous means inclusive of gravure coating, gravure reverse coating or roll coating, followed by drying. That layer 2 may preferably have a thickness of about 0.1 .mu.m to about 20 .mu.m.
In order to make these layers more transferable, it is additionally provided with the heat-sensitive adhesive layer 5 on the surface of the transparent resin layer. This layer 5 may be formed by the coating and drying of a solution of a thermoplastic resin whose Tg lies in the range of 40.degree.-75.degree. C., preferably 60.degree.-70.degree. C., e.g. a resin having an improved hot adhesiveness such as acrylic resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride/vinyl acetate copolymer resin and polyester resin, and may preferably have a thickness of about 0.1 .mu.m to about 10 .mu.m.
At a Tg lower than 40.degree. C., the aforesaid heat-sensitive adhesive layer is softened when the resulting image is used at a relatively high temperature, so that micro-cracking can occur an the transparent resin layer, resulting in degradation of its chemical resistance, esp. its resistance to plasticizers. At a Tg higher than 75.degree. C., on the other hand, not only is the image to be covered made less adhesive to the transparent resin layer even with the heat emitted from a thermal head, but the "foil cutting" of the transparent resin layer also drops, making it difficult to perform transfer with high resolution.
Similar to those so far known in the art, the heat transfer sheet used in this invention may include a substrate film having a thickness of about 0.5 .mu.m to about 50 .mu.m, preferably about 3 .mu.m to about 10 .mu.m, for instance, a film made of polyethylene terephthalate, polystyrene, polysulfone and cellophane, and a dye layer formed thereon, comprising a sublimable dye, preferably a dye having a molecular weight of about 250 or higher and a binder resin based on, e.g. cellulose, acetal, butyral and polyester. This film is only different from the conventional ones in that said dye layer is permitted to contain a relatively large amount of a releasant. It is noted that a releasant is added to both the dye layer and the dye-receiving layer in the prior art so as to prevent their fusion at the time of heat transfer. In the present disclosure, however, the wording "a relatively large amount" is understood to mean that a substantial portion or 100% by weight to 50% by weight of the releasant added is contained in the dye layer.
The substrate film 11 may be made of a material similar that used for the aforesaid heat transfer sheet. As the transparent resins employed for the aforesaid transparent protective film 1, use may be made of, in addition to such resins as mentioned in connection with the 1st to 4th aspects, acrylic resin, acrylic/vinyl chloride/vinyl acetate copolymer resin, chlorinated rubber, acrylic/chlorinated rubber resin, vinyl chloride/vinyl acetate copolymer resin, ultraviolet ray- or electron beam-curable resin and so on. The substrate film may preferably have a thickness of about 0.5 .mu.m to about 10 .mu.m.
Prior to forming the aforesaid transparent protective layer 12, it is preferable to provide a release layer 13 on the surface of the substrate film 11. Such a release layer 13, for instance, is made of such materials as acrylic resin, acrylic/vinyl chloride/vinyl acetate copolymer resin, chlorinated polypropylene resin and waxes, e.g. carnauba wax. Preferably, that release layer has a thickness of about 0.1 .mu.m to about 2 .mu.m.
In order to make these layers more transferable, a heat-sensitive adhesive layer 14 may be additionally provided on the surface of the transparent resin layer 12. This adhesive layer 14, for instance, may be made of resins having an improved hot adhesiveness such as acrylic resin, vinyl chloride resin, vinyl chloride/vinyl acetate copolymer resin, chlorinated polypropylene resins, polyester resin and polyamide resin, and may have preferably a thickness of about 0.3 .mu.m to about about 5 .mu.m.
Of importance in this case is the thickness of the adhesive layer formed. At too large a thickness the heat sensitivity of the sublimation type of dye layer drops, whereas at too small a thickness such unusual transfer of dye layers as mentioned above takes place. Thus the adhesive layer should have a thickness lying in the range of 0.001 to 1 .mu.m, preferably 0.05 to 0.5 .mu.m.
It is particularly preferred that the adhesive layer formed be of uniform thickness. For instance, this is achieved by forming a few-.mu.m thick adhesive layer before stretching the polyester film and then biaxially stretching that film, whereby the adhesive layer can be made uniform and reduced to as thin as 1 .mu.m or less in thickness.
Such a substrate sheet as aforesaid may have a thickness enough to assure some heat resistance and strength, say, 0.5 to 50 .mu.m, preferably about 3 .mu.m to about 10 .mu.m.
The dye layer formed in this manner may have a thickness of 0.2 to 5.0 .mu.m, preferably about 0.4 to about 2.0 .mu.m, and the sublimable dye may preferably account for 5 to 90% by weight, preferably 10 to 70% by weight of the dye layer.
In order to form the heat meltable ink layer on the substrate sheet, the aforesaid ink materials may be coated thereon by not only hot melt coating but also a number of other coating means as well, inclusive of hot melt coating, hot lacquer coating, gravure coating, gravure reverse coating and roll coating. Required to be determined with harmony between the required density and heat sensitivity in mind, the ink layer formed preferably lies in the range of 0.2 to 3.0 .mu.m. At too small a thickness the reflection density of the transfer image is insufficient, whereas at too large a thickness the "foil cutting" at the time of printing degrades, resulting in a drop of the sharpness of the printed image.
In this invention, the substrate sheet has preferably included a release protective layer on its surface before forming the aforesaid ink layer. This release protective layer serves to improve the releasability of the ink layer and is transferred along with the ink layer, giving a surface protective layer on the transfer image and thereby improving its rub resistance, etc. Such a release protective layer may be made of (meth)acrylic resin, silicone base resin, fluorine base resin, cellulosic resin such as cellulose acetate, epoxy base resin, polyvinyl alcohol and the like, which contain waxes, organic pigments, inorganic pigments and the like, and may preferably have a thickness of 0.2 to 2.5 .mu.m. At too small a thickness it fails to produce sufficient protective effects such as scratch resistance, whereas at too large a thickness the "foil cutting" at the time of printing goes worse.
In this invention, it is preferred that a heat-sensitive adhesive layer be additionally provided on the aforesaid ink layer. This adhesive layer should again be chosen in consideration of its adhesion to the associated image-receiving material. For instance, when the image-receiving material is a card material made of a resin based on vinyl chloride, it is preferable to use such a well-adhesive thermoplastic resin as aforesaid. The adhesive layer formed should preferably have a thickness lying in the range of 0.05 to 1.0 .mu.m. At too small a thickness no desired adhesion is obtained, whereas at too large a thickness the "foil cutting" at the time of printing goes worse.
Energy applicator means so far known in the art may all be used to apply heat energy to carry out heat transfer with such heat transfer sheet and image-receiving material as mentioned above. For instance, the desired images may be obtained by the application of a heat energy of about 5 mJ/mm.sup.2 to about 100 mJ/mm.sup.2 for a time controlled by recording hardware such as a thermal printer (e.g. Video Printer VY-100 made by Hitachi, Ltd.)
Disperse dye (Macrolex Yellow 6G made
5.5     parts
Polyvinyl butyral resin (Eslec BX-1 made
4.5     parts
89.5    parts
Provided as a substrate film was a 6.0-.mu.m thick polyester film Lumirror made by Toray Industries, Ltd.) having on its back surface a heat-resistant slip layer (of 1 .mu.m in thickness) and on its front surface a primer layer (of 0.5 .mu.m in thickness) comprising a polyurethane base resin. Using gravure coating, the aforesaid ink compositions were successively and repeatedly coated on the front surface of the substrate film in the order of yellow, magenta and cyan, at a width of 15 cm and to a coverage of about 3 g/m.sup.2. Subsequent drying gave a sublimation type of heat transfer sheet containing sublimable dye layers of three different colors.
The following wax ink composition, heated at a temperature of 100.degree. C., was coated on the same substrate film as used in Reference Ex. A1 but including no primer layer, to a coverage of about 4 g/m.sup.2 by hot melt roll coating, thereby preparing a wax type of heat transfer sheet.
Ester wax             10 parts
Wax oxide             10 parts
Paraffin wax          60 parts
Carbon black          12 parts
Using gravure coating, the following ink composition was coated on the same substrate film as used in Reference Ex. A2 at a ratio of 1 g/m.sup.2 on dry solid basis. Subsequent drying gave a release layer.
Silicone base resin    10       parts
10       parts
Methyl ethyl ketone    100      parts
Toluene                100      parts
Then, the following ink was coated on the surface of the aforesaid release layer at a ratio of 10 g/m.sup.2 on dry solid basis. Subsequent drying gave an ionizing radiation-curable resin layer.
Polymethyl methacrylate   20     parts
Polyethylene wax          3      parts
Methyl ethyl ketone       250    parts
Toluene                   250    parts
Then, the following ink composition was coated on the surface of the aforesaid resin layer at a ratio of 1 g/m.sup.2 on dry solid basis, followed by drying which gave an adhesive layer. After that, the product was exposed to electron beams of 180 KV at a dose of 5 Mrad in a nitrogen atmosphere of 10.sup.-7 Torr with an electron beam irradiator made by Nisshin High Voltage Co., Ltd. to cure the ionizing radiation-curable resin layer, thereby obtaining a heat transfer cover film according to this invention.
Methyl ethyl ketone       100 parts
Toluene                   100 parts
60      parts
10      parts
Polymethyl methacrylate  30      parts
3       parts
Methyl ethyl ketone      200     parts
Toluene                  200     parts
Methyl ethyl ketone    50 parts
Toluene                50 parts
Cellulose resin (CAB381-0.1)
Methyl ethyl ketone     50 parts
Toluene                 50 parts
Gloss    Pencil Hardness
A.Ex. A1    .circleincircle.
72%      2H
A2    .circleincircle.
81%      2H
C.Ex. A1    --    x          14%      4B
A2    x     .smallcircle.
59%      H
A3    x     .smallcircle.
28%      H
Film Cutting: Determined in terms of the releasability of films after
transfer and by observing the transfer images under a microscope.
.circleincircle.:Releasing is very easy and the ionizing radiationcured
resin layers are sharply cut along the contours of the the images.
x: There is considerable resistance to releasing with the edges of the
resin layers lacking uniformity.
Rub Resistance: Measured by rubbing the surfaces of the images 100 times
with gauze impregnated with isopropyl alcohol.
.circleincircle.: The gauze is not stained at all.
.smallcircle.: The gauze is somewhat stained.
Disperse dye (Macrolex Yellow 6G
89.0    parts
Provided as a substrate film was a 6.0-.mu.m thick polyester film (Lumirror made by Toray Industries, Ltd.) having on its back surface a heat-resistant slip layer (of 1 .mu.m in thickness) and on its front surface a primer layer (of 0.5 .mu.m in thickness) comprising a polyurethane base resin. Using gravure coating, the aforesaid ink compositions were successively and repeatedly coated on the front surface of the substrate film in the order of yellow, magenta and cyan, at a width of 15 cm and to a coverage of about 3 g/m.sup.2. Subsequent drying gave a sublimation type of heat transfer sheet containing sublimable dye layers of three different colors.
The following wax ink composition, heated at a temperature of 100.degree. C., was coated on the same substrate film as used in Reference Ex. B1 but including no primer layer, to a coverage of about 4 g/m.sup.2 by hot melt roll coating, thereby preparing a wax type of heat transfer sheet.
Carbon black            10 parts
Toluene                 35 parts
Methyl ethyl ketone     35 parts
Using gravure coating, the following ink composition was coated on the same substrate film as used in Reference Ex. B2 at a ratio of 1 g/m.sup.2 on dry solid basis. Subsequent drying gave a release layer.
Acrylic resin           20 parts
Methyl ethyl ketone    100 parts
Toluene                100 parts
Then, the following ink was coated on the surface of the aforesaid release layer at a ratio of 3 g/m.sup.2 on dry solid basis. Subsequent drying gave a transparent resin layer.
Acrylic resin            20 parts
Polyethylene wax          1 part
Methyl ethyl ketone      50 parts
Toluene                  50 parts
Then, the following ink composition was coated on the surface of the aforesaid resin layer at a ratio of 1 g/m.sup.2 on dry solid basis, followed by drying which gave an adhesive layer. In this way, a heat transfer cover film according to this invention was prepared.
Acrylic resin           10 parts
Water                    20 parts
Isopropyl alcohol        10 parts
Acrylic resin            21 parts
B.T.  A.T.
A.Ex. B1    .smallcircle.
82%   78%
B2    .circleincircle.
73%   71%
C.Ex. B1    --          x          14%    7%
B2    x           .circleincircle.
81%   43%
.circleincircle.: Releasing is very easy and the transparent resin layers
are sharply cut along the contours of the images.
.smallcircle.: There is some resistance to releasing with the edges of th
transparent resin layers lacking uniformity slightly.
transparent resin layers lacking uniformity.
Gloss: Determined by rubbing the images 100 times with synthetic paper to
measure a change in glossiness (gloss value in %).
The following wax ink composition, heated at a temperature of 100.degree. C., was coated on the same substrate film as used in Reference Ex. C1 but including no primer layer, to a coverage of about 4 g/m.sup.2 by hot melt roll coating, thereby preparing a wax type of heat transfer sheet.
Using gravure coating, the following ink composition was coated on the same substrate film as used in Reference Ex. C2 at a ratio of 1 g/m.sup.2 on dry solid basis. Subsequent drying gave a transparent resin layer.
Microsilica               20 parts
Methyl ethyl ketone       20 parts
Toluene                   20 parts
Then, the following ink was coated on the surface of the aforesaid resin layer at a rate of 0.5 g/m.sup.2 on dry solid basis. Subsequent drying gave an adhesive layer. In this way, a heat transfer cover film according to this invention was obtained.
50     parts
Microsilica               0.4    parts
Modified ethanol          50     parts
Microsilica             0.4     parts
Methyl ethyl ketone     20      parts
Toluene                 20      parts
Acrylic resin (BR-83 made by Mitsubishi
Polyethylene wax          1     part
Methyl ethyl ketone       40    parts
Toluene                   10    parts
(Coated to a coverage of 4 g/m.sup.2).
HS-32G (made by Showa Ink Kogyo K.K.)
Microsilica               2     parts
Ethyl acetate             25    parts
Toluene                   25    parts
(Coated to a coverage of 1 g/m.sup.2).
The cards obtained as aforesaid were estimated. The results are reported in Table 3.
What was Estimated     C1 C2 C1     C2
Vinyl chloride card at 40.degree. C., 90% RH and 200
bad    bad
gf/cm.sup.2 for 10 days
Eraser at 60.degree. C. and 500 gf/cm.sup.2 for 30 min.
Gasoline 2 min.        good
Trichloroethane 2 min. good
Kerosene 2 min.        good
5% saline 24 hrs.      good
Gasoline               good
Trichloroethane        good
Kerosene               good
--     bad
Foil cutting           good
5.5    parts
4.5    parts
89.5   parts
This ink was similar to the yellow ink, provided that a cyan disperse dye (Solvent Blue 63) was used. Provided as a substrate film was a 6.0-.mu.m thick polyester film (Lumirror made by Toray Industries, Ltd.) having on its back surface a heat-resistant slip layer (of 1 .mu.m in thickness) and on its front surface a primer layer (of 0.5 .mu.m in thickness) comprising a polyurethane base resin. Using gravure coating, the aforesaid ink compositions were successively and repeatedly coated on the front surface of the substrate film in the order of yellow, magenta and cyan, at a width of 15 cm and to a coverage of about 3 g/m.sup.2. Subsequent drying gave a sublimation type of heat transfer sheet containing sublimable dye layers of three different colors.
The following wax ink composition, heated at a temperature of 100.degree. C., was coated on the same substrate film as used in Reference Ex. D1 but including no primer layer, to a coverage of about 4 g/m.sup.2 by hot melt roll coating, thereby preparing a wax type of heat transfer sheet.
Carbon black          10 parts
Toluene               35 parts
Methyl ethyl ketone   35 parts
Using gravure coating, the following ink composition was coated on the same substrate film as used in Reference Ex. D2 at a ratio of 1 g/m.sup.2 on dry solid basis. Subsequent drying gave a transparent resin layer.
Methyl ethyl ketone   20 parts
Toluene               20 parts
Then, the following ink was coated on the surface of the aforesaid resin layer at a rate of 0.7 g/m.sup.2 on dry solid basis. Subsequent drying gave an adhesive layer. In this manner, a heat transfer cover film according to this invention was obtained.
30    parts
(VYLF made by UCC; Tg = 68.degree. C. and
Microsilica               0.4   parts
Methyl ethyl ketone       35    parts
Toluene                   35    parts
The procedures of Ex. D1 were followed with the exception that a vinyl chloride/vinyl acetate copolymer (Denka Lac #21ZA made by Denki Kagaku Kogyo K.K.; and with Tg=62.degree. C. and a polymerization degree of 240) was used as the adhesive, thereby obtaining a heat transfer cover film according to this invention.
The procedures of Ex. D1 were followed with the exception that a vinyl chloride/vinyl acetate copolymer (VYHH made by UCC; and with Tg=72.degree. C. and a polymerization degree of 450) was used as the adhesive, thereby obtaining a heat transfer cover film according to this invention.
A cover film was prepared by following the procedures of Example D1 with the proviso that an acrylic resin (BR-102 made by Mitsubishi Rayon Co., Ltd.; and with Tg=20.degree. C. and a polymerization degree of 5,000) was used as the adhesive. With this cover film, a card was obtained by following the procedures of Application Ex. D1.
A cover film was prepared by following the procedures of Example D1 with the proviso that a vinyl chloride/vinyl acetate copolymer (VAGH made by UCC; and with Tg=79.degree. C. and a polymerization degree of 450) was used as the adhesive. With this cover film, a card was obtained by following the procedures of Application Ex. D1.
A cover film was prepared by following the procedures of Example D1 with the proviso that a vinyl chloride/vinyl acetate copolymer (VYNS made by UCC; and with Tg=79.degree. C. and a polymerization degree of 700) was used as the adhesive. With this cover film, a card was obtained by following the procedures of Application Ex. D1.
What was Estimated   D1    D2    D3  D1  D2  D3
Vinyl chloride card at 40.degree. C., 90% RH
and 200 gf/cm.sup.2 for 10 days
Eraser at 60.degree. C. and 500 gf/cm.sup.2 for 30
Foil cutting         .largecircle.
Gasoline 2 min.      .largecircle.
According to the present invention as aforesaid, wherein the heat-sensitive adhesive layer formed on the surface of the transparent resin layer is made of a resin whose Tg lies in the range of 40.degree. to 75.degree. C., the transparent resin layer can be well transferred on an image, while it can be well cut, by means of a thermal head. Thus, since the transparent resin layer is easily transferable onto the image by the heat of the thermal head, it is possible to provide expeditious production of an image representation improved in terms of such properties as durability, esp. rub resistance, chemical resistance and solvent resistance.
By gravure coating, the aforesaid coating solution was coated on one surface of a 6.0-.mu.m thick polyester film having a heat-resistant slip layer on the other surface (S-PET made by Toyobo Co., Ltd.) to a coverage of about 3 g/m.sup.2 on dry solid basis. Subsequent drying gave a heat transfer sheet.
With a Miya bar #20, the aforesaid coating solution was coated on the surface of a white polyethylene terephthalate film (PETE-20 made by Toray Industries, Inc.; and with a thickness of 188 .mu.m) at a rate of 5 g/m.sup.2 on dry solid basis. Subsequent drying gave a heat transfer sheet.
Nought decimal five (0.5) g/m.sup.2 of a release layer (an acrylic resin TP-64 Varnish made by DIC K.K.), 3.0 g/m.sup.2 of a transparent protective layer (an acrylic resin BR-53 made by Mitsubishi Rayon Co., Ltd. and 0.5 g/m.sup.2 of a heat-sensitive adhesive layer (a vinyl chloride/vinyl acetate copolymer Denka 1000A made by Denki Kagaku Kogyo K.K.) were successively coated on the surface of a polyethylene terephthalate film (S-PET made by Toyobo Co., Ltd.; and with a thickness of 9 .mu.m). Subsequent drying gave a heat transfer cover film.
The heat transfer sheet was overlaid on the heat transfer image-receiving sheet while the former's dye layer was in opposition to the latter's dye-receiving layer. With a thermal sublimation type of transfer printer (VY50 made by Hitachi, Ltd.), a printing energy of 90 mJ/mm.sup.2 was then applied to the back side of the heat transfer sheet through the thermal head to make an image. Finally, the transparent protective. film was transferred from the heat transfer cover film onto the image under similar conditions. In consequence, the transparent protective layer could be easily transferred onto the image. They remained so well bonded to each other that they could hardly be separated from each other.
The transfer of the transparent protective layer was performed with a laminators made by Meiko Shokai K.K. As a result, that layer could be easily transferred onto the image. They remained so well bonded to each other that they could hardly be separated from each other.
Fluorine-modified silicone (FL100
60.0   parts
Disperse dye (PTY-52 made by
60.0   parts,
20.0   parts
Amino-modified silicone (KF-343 made by
80.0   parts.
Provided as a substrate film was a 6-.mu.m thick polyethylene terephthalate film having a 0.1-.mu.m thick, easily bondable layer on one surface and a heat-resistant slip layer on the other surface. A toluene solution of an acrylic resin comprising 10 parts of TR-64 Varnish (made by Dainippon Ink & Chemicals, Inc.) and 40 parts of toluene was coated on said one surface of the polyethylene terephthalate film, while leaving three regions of A4 size, to a dry thickness of 0.7 .mu.m, followed by drying which resulted in a releasable protective layer being formed on such regions.
Subsequently, a black ink comprising 10 parts of MSF (made by Toyo Ink Mfg. Co., Ltd.) and 40 parts of toluene was coated on the surface of that layer to a dry thickness of 2 .mu.m, followed by drying which gave a heat-meltable ink layer. Further, a toluene solution of an acrylic resin comprising 10 parts of TR-64 varnish (made by Dainippon Ink & Chemicals, Inc.) and 40 parts of toluene was coated on the surface of that ink layer to a dry thickness of 0.5 .mu.m, followed by drying which gave a heat-sensitive adhesive layer.
Moreover, three ink compositions of different colors forming the dye layer were successively gravure printed between the aforesaid ink layers to a dry thickness of 1.0 g/m.sup.2 in the order of yellow, magenta and cyan. Subsequently drying gave a heat transfer sheet of this invention in the form of a continuous film.
PTY-52 (C.I. Disperse Yellow 141 made by
4.80 parts
Methyl ethyl ketone       55.00 parts
Toluene                   34.70 parts
Releasant                 1.03 parts
MS Red G (C.I. Disperse Red 60 made by
2.60 parts
Macrolex Red Violet R (C.I. Disperse
1.40 parts
Methyl ethyl ketone       43.34 parts
Toluene                   43.34 parts
Releasant                 0.40 parts
Methyl ethyl ketone       22.54 parts
Toluene                   68.18 parts
Releasant                 0.94 parts
A heat transfer sheet was obtained by following the procedures of Example E1 with the exception that the releasable protective layer having a dry thickness of 0.5 .mu.m was made from an acrylic/vinylic resin solution comprising 10 parts of MCS-5065 (made by Dainippon Ink & Chemicals, Inc.) and 40 parts of toluene.
A heat transfer sheet was obtained by following the procedures of Example E1 with the exception that the releasable protective layer having a dry thickness of 0.5 .mu.m was made from a chlorinated polyolefinic resin solution comprising 10 parts of TR-15 varnish (made by Dainippon Ink & Chemicals, Inc.) and 40 parts of toluene.
A heat transfer sheet according to this invention was obtained by following the procedures of Example E1 with the exception that the substrate film used was a polyethylene naphthalate film (6 .mu.m in thickness) including an easily bondable layer (of 0.2 .mu.m in thickness) made of a heat-curable epoxy resin.
Comparative Example F13
With the following components, a white card substrate core (of 0.2 .mu.m in thickness and 30.times.30 cm in size) was prepared.
Plasticizer (DOP)        3      parts
F1              Not found    Good
F2              Not found    Good
F3              Not found    Good
F4              Not found    Good
F1              found        Bad
F2              found        Bad
Ethyl alcohol         49.0 parts
Pure water            49.9 parts
a transparent resin layer releasably provided on the substrate film, said transparent resin layer comprising at least one material selected from the group consisting of a wax, a slip agent, an ultraviolet absorber, an antioxidant and a fluorescent brightener;
a release layer interleaved between said substrate film and said transparent resin layer, said release layer comprising a water soluble polymer selected from the group consisting of polyvinyl alcohol, polyvinyl pyrrolidone, gelatin, carboxymethylcellulose, methylcellulose, polyethylene oxide, gum arabic, water soluble butyral, water soluble polyester, water soluble polyurethane, water soluble polyacrylic, water soluble polyamide, and mixtures thereof;
a heat-sensitive adhesive layer provided on said transparent resin layer, said heat-sensitive adhesive layer comprising a resin having a mean polymerization degree of 50-300 and a glass transition temperature lying in the range of 40.degree. to 75.degree. C., said resin being selected from the group consisting of polyvinyl chloride, polyvinyl acetate, a vinyl chloride/vinyl acetate copolymer and mixtures thereof; and
a dye layer provided on said substrate film.
3957694 May 18, 1976 Bolon et al.
4484204 November 20, 1984 Yamamoto et al.
4522881 June 11, 1985 Kobayashi et al.
5244234 September 14, 1993 Oshima et al.
2524846 October 1983 FRX
58-149049 September 1983 JPX
59-85793 May 1984 JPX
59127798 July 1984 JPX
60-064895 April 1985 JPX
60-115025 June 1985 JPX
60-204397 October 1985 JPX
61-162388 July 1986 JPX
1-155478 July 1986 JPX
62-39298 February 1987 JPX
62-214990 September 1987 JPX
62-251190 October 1987 JPX
63-293099 November 1988 JPX
1-58590 March 1989 JPX
1-202492 August 1989 JPX
Inventors: Katsuyuki Oshima (Tokyo), Jitsuhiko Ando (Tokyo), Masanori Torii (Tokyo)
Law Firm: Parkhurst, Wendel & Burr, LLP
Application Number: 8/451,971
Current U.S. Class: Having Plural Interactive Leaves (503/227); 428/195; 428/4231; 428/4744; 428/4782; Of Polyester (e.g., Alkyd, Etc.) (428/480); 428/484; 428/4884; Of Addition Polymer From Unsaturated Monomers (428/500); Ester, Halide Or Nitrile Of Addition Polymer (428/520); Of Carbohydrate (428/532); Fluroescent, Phosphorescent, Or Luminescent Layer (428/690); Material Designed To Be Responsive To Temperature, Light, Moisture, Etc. (428/913); Transfer Or Decalcomania (428/914)