JPH1044611A - Thermal transfer cover film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of jamming by containing particles in a heat-sensitive bonding agent layer, roughening its surface and lowering the contact area with an image receiving paper or the like. SOLUTION: A thermal transfer cover film 10 is constituted of a transparent resin layer 2 and a heat-sensitive bonding layer 3 formed successively on a base film 1. Various kinds of base films used for a thermal transfer sheet publicly known heretofore can be used as a base film 1. Various kinds of resin of superior resistance to wear, resistance to chemicals, transparent hardness and the like can be used for the transparent resin layer 2. The heat-sensitive bonding agent layer 3 is a transparent layer formed of fine particles in a thermoplastic resin of good heat bonding, and its thickness is approximately 0.1-10μm. As for the fine particles contianed in the heat-sensitive bonding agent layer, an inorganic pigment, resin particles, wax particles or the like are used, and the particle diameters are 0.1-10μm and the content to be contained is 0.1-10 pts.wt. thin of 100 pts.wt. to be used for the heat-sensitive bonding agent layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer cover film in which a cover film is formed by thermal transfer on a transfer receiving member such as an image receiving paper on which an image is formed. In particular, the present invention relates to a thermal transfer cover film that is less likely to cause a transport error in a printer.

[0002]

2. Description of the Related Art At present, a thermal transfer recording method is widely used as a simple printing method. Since the thermal transfer recording method can easily form various images, the number of printed sheets may be relatively small, such as the production of ID cards such as identification cards and business photographs, or personal computer printers and video printers. It's being used. When a full-color gradation image such as a face photograph is preferable as a thermal transfer sheet to be used, an ink layer such as yellow, magenta, and cyan (and further, if necessary) is formed on a continuous base film. And black) are repeatedly provided face-to-face. Such a thermal transfer sheet is roughly classified into a so-called fusion transfer type thermal transfer sheet in which the color material layer is melted and softened by heating and the color material layer itself is transferred to a transfer target. Is a so-called sublimation type thermal transfer sheet in which only the dye is sublimated and only the dye is transferred to the transfer target.

[0003] Using such a thermal transfer sheet, for example,
When creating an ID card such as an identification card, a fusion transfer type can easily form a line drawing image such as a character or a number, but has a drawback that the obtained image has poor durability, particularly abrasion resistance. . On the other hand, the sublimation type is suitable for forming a gradation image such as a face photograph, but the obtained image is inferior in durability such as abrasion resistance because there is no vehicle unlike a normal printing ink. When it comes into contact with a card case, a file sheet, a plastic eraser or the like containing a plasticizer, there is a drawback that the dyes are transferred to these and the chemical resistance such as image bleeding and the solvent resistance are poor. So, wear resistance,
For the purpose of imparting improved durability such as chemical resistance and solvent resistance to the formed image, it has been attempted to further provide a cover film as a protective layer on the formed image by transfer.
For example, by using a heat transfer cover film provided with a heat-sensitive adhesive layer on a transparent resin layer provided releasably on a base film, the transparent resin layer can be formed on the image-formed transfer object by using a heat-sensitive adhesive layer. Is transferred and laminated.

[0004]

However, since the heat-sensitive adhesive layer in the conventional thermal transfer cover film is designed by using only the resin, the coefficient of friction with the transfer object such as an image receiving paper becomes very high. I have. For this reason, in a recent printer mechanism of a compact design, when the thermal transfer cover film and the image receiving paper are conveyed, it is difficult for the thermal transfer cover film and the image receiving paper to come off while in contact with each other, and a jam may occur. That is, in the case of the printer shown in the conceptual diagram of FIG. 6, due to space constraints, the thermal transfer cover film 64 and the image-receiving paper 6 having the image formed thereon are controlled by the platen roller 61 and the roller 63 installed immediately before the thermal head 62.
5 is a mechanism that sandwiches both of them from the front and back and transports and supplies them between the platen roller 61 and the thermal head 62. Then, after the transfer of the thermal transfer cover film is completed, when the thermal transfer cover film and the image receiving paper are respectively conveyed to the standby position for the next transfer, the rollers 63 are separated from each other to be in an open state. The paper is separated from the paper 65 and transported to the respective standby positions. At this time, since the respective transport amounts are not the same (when using a thermal transfer cover film having an ink layer area,
The transfer direction of moving the thermal transfer cover film forward is not the same, although the image receiving paper after image formation is retracted.) If the transport is performed with the separation incomplete, the thermal transfer cover film is usually weaker than the image receiving paper. However, a situation occurs in which the sheet is transported around the image receiving paper. Further, in a large-size printer, wrinkles occur due to the slippage between the thermal transfer cover film and the image receiving paper. In particular, the mounting accuracy of the cassette or the film is poor, and it appears remarkably when the film is fed obliquely.

[0005]

In order to solve the above-mentioned problems, the heat transfer cover film of the present invention has a transparent resin layer provided on a base film so as to be peelable, and a heat-sensitive adhesive layer is further provided on the surface thereof. In the thermal transfer cover film provided, fine particles were contained in the heat-sensitive adhesive layer. These fine particles cause the surface of the heat-sensitive adhesive layer to have irregularities, and even when the surface of the heat-sensitive adhesive layer comes into surface contact with the image receiving paper, the contact area is reduced and the friction coefficient is reduced, so that jamming during conveyance in the printer can be eliminated. Further, by providing the release layer between the base film and the transparent resin layer, the transfer transfer of the transparent resin layer and the heat-sensitive adhesive layer to the transfer object can be stably performed regardless of the material of the base film. Further, if an ultraviolet blocking layer is provided between the transparent resin layer and the heat-sensitive adhesive layer, an image resistant to ultraviolet light can be obtained. For the purpose of simplifying the layer structure, an ultraviolet absorber may be contained in the heat-sensitive adhesive layer. In addition, the cover film region having the transparent resin layer and the like, and the ink layer region having at least one color material layer, a long strip-shaped configuration in which a large number of surface layers are repeatedly provided on the same base film. By forming a thermal transfer cover film, after an image is formed in the ink layer area, a cover film can be formed on the image in the cover film area continuously with one transfer sheet. As the color material layer in the ink layer region, for example, a structure having at least one color or more of a dye layer and a molten black layer in a plane-sequential manner is used. The thermal transfer cover film also has an ink layer region suitable for both the gradation image and the line drawing image by using the heat transfer cover film.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the thermal transfer cover film of the present invention will be described with reference to the drawings. FIG.
FIG. 1 is a cross-sectional view showing one embodiment of the thermal transfer cover film of the present invention. As shown in FIG.
Reference numeral 0 denotes a configuration in which a transparent resin layer 2 and a heat-sensitive adhesive layer 3 are sequentially provided on a base film 1. FIG. 2 is a sectional view showing another embodiment, and the heat transfer cover film 10a shown in FIG.
Is a configuration in which a release layer 4 is provided between the base film 1 and the transparent resin layer 2 in the configuration of FIG. FIG. 3 is a cross-sectional view showing another embodiment. The thermal transfer cover film 10b shown in FIG. 3 is different from the structure shown in FIG.
The configuration is such that an ultraviolet blocking layer 5 is provided between them. FIG. 4 is also a cross-sectional view showing another embodiment. The thermal transfer cover film 10c shown in FIG. 4 is different from the configuration shown in FIG.

As another form of the thermal transfer cover film of the present invention, a cover film region composed of a transparent resin layer or the like used for forming a cover film is provided in the above-described various forms, and a color material layer or the like used for forming an image is formed. A large number of ink layer regions may be alternately and repeatedly provided in a face-sequential manner with the cover film region. FIG. 5 shows an example of a thermal transfer cover film 10d. That is, the thermal transfer cover film 1 illustrated in FIG.
0d indicates that a large number of cover film regions 7 and ink layer regions 8 are alternately arranged in the longitudinal direction.
Has a configuration in which a yellow portion Y, a magenta portion M, a cyan portion C, and a black portion Bk are partitioned in the order used according to the color of the color material layer. The ink layer region 8 is a portion of a thermal transfer sheet for image formation, in which the substrate film 1 is shared with the cover film region 7 as a support, and at least a color material layer is provided on the substrate film 1. It is. Although not shown, a detection mark for mechanically detecting the head of each color or the head of the cover film may be provided in the vicinity of a side portion of the long band-shaped thermal transfer cover film.

In the case of a thermal transfer cover film 10d having a configuration in which ink layer regions 8 and cover film regions 7 are alternately arranged as illustrated in FIG. 5, the layer structure in the cover film region depends on the application as shown in FIG. 4 to 4 are appropriately selected. Similarly, the color material layer for forming an image, which is provided on the base film 1 in the ink layer region 8, or the content of the layer configuration of the ink layer region is determined by various conventionally known thermal transfer recording methods. Color material layer,
A layer configuration is sufficient. For example, the color of the color material layer is only one color of black or another color, or three colors of yellow, magenta, and cyan.
Any color, or four process colors including black in addition to these three colors, or any other color, among others, three color process colors of yellow, magenta, and cyan, or black in addition to these three colors The four process colors can also record a full-color image, and are highly practical. The thermal transfer recording method of the color material layer may be, for example, a sublimation transfer type, a melt transfer type, or the like. When the ink layer region is divided into a plurality of colors, in addition to the configuration in which all of the partitions are of the sublimation transfer type or the melt transfer type, the sublimation transfer type and the melt transfer type are selectively used depending on the color. It is good also as composition which also has a type. One preferred embodiment is, for example, a three-color process of yellow Y, magenta M, and cyan C necessary as a process color in the ink layer region 8 of the thermal transfer cover film 10d illustrated in FIG.
The color material layer of the color is a dye sublimation transfer type, and the black color material layer is a fusion transfer type molten black layer. With such a configuration, the sublimation transfer type portion is used exclusively for forming a color image of gradation expression,
By using the black fusion transfer type part for forming line drawing images, a thermal transfer cover film with an ink layer area suitable for both gradation images with excellent gradation expression and sharp and clear line drawing images can do.

Next, the material of each layer constituting the thermal transfer cover film of the present invention will be described.

First, as the substrate film 1 serving as a support, various types of substrate films used in conventionally known thermal transfer sheets can be used, and other films having desired strength, heat resistance and the like can be used. There is no particular limitation as long as it has physical properties. Preferred examples of the base film 1 include polyester films such as polyethylene terephthalate, polypropylene, polycarbonate, cellophane, cellulose acetate, polyethylene, polyvinyl chloride, and the like.
In addition to plastic films such as polystyrene, polyamide, polyimide, polyvinylidene chloride, and ionomer, thin paper such as glassine paper, capacitor paper, and paraffin paper, or a laminate of two or more of these may be used. The thickness is appropriately selected according to the material to be used so that the strength and heat resistance are appropriate, but the thickness is preferably 3 to 100 μm. If it is too thick, heat will not be easily transmitted when heated from the back side by a heating means such as a thermal head, and if it is too thin, strength, heat resistance, etc. will decrease. Note that, among the above materials, polyethylene terephthalate is one of the preferable materials in terms of strength, heat resistance, and the like.

When the transfer of the cover film is performed by heating using a thermal head, the cover film is temporarily exposed to high heat.
By providing the heat-resistant back layer 6, the heat resistance of the base film used can be supplemented. Further, the back layer may be provided for imparting lubricity for improving transportability, or for imparting both heat resistance and lubricity, imparting antistatic ability, and the like.

Next, as the transparent resin layer 2, wear resistance,
Various resins excellent in chemical resistance, transparency, hardness, etc. can be used, for example, vinyl chloride-vinyl acetate copolymer, polyester resin, polystyrene resin, acrylic resin, polyurethane resin, acrylic urethane resin, or a resin of these resins. Examples include silicone-modified resins, and mixtures thereof. Although these resins are excellent in transparency, they tend to form a relatively tough film, so if the foil is insufficiently cut at the time of transfer, the resin may be silica, alumina, calcium carbonate, plastic pigment, or the like. May be added to the extent that the transparency is not impaired. For the purpose of improving the scratch resistance of the surface after the transfer, a wax may be added in an amount of about 0.1 to 10% by weight based on the total amount of the resin. Examples of the wax used include polyethylene wax, carnauba wax and the like.
In order to form the transparent resin layer 2 on the base film 1, a coating solution or ink containing the above resin is coated with a coating means such as gravure coating, gravure reverse coating, roll coating, or printing such as gravure printing or screen printing. Various known film forming means such as means may be used. In the case where the ink layer area and the cover film area are alternately and sequentially provided in a plane, a coating means capable of partial coating or a printing means such as gravure printing or screen printing is used. In addition, the thickness of the transparent resin layer is preferably about 0.1 to 20 μm. If it is too thin, the function of the protective layer as a cover film cannot be sufficiently obtained, and if it is too thick, the performance becomes excessive.

If the transferability of a layer to be transferred, such as the transparent resin layer 2, which is in contact with the base film 1 is not appropriate,
A release layer 4 may be provided in advance on the base film 1 in order to appropriately adjust the releasability (see FIGS. 2 and 3). Examples of the release layer 4 include various waxes such as silicone wax, silicone resin, fluorine resin, acrylic resin, polyurethane resin, polyvinyl pyrrolidone,
Polyvinyl alcohol and the like. The type of the release layer is appropriately selected from those that transfer to the object to be transferred during transfer, those that remain on the substrate film side, and those that cause cohesive failure. The method for forming the release layer may be the same as the method for forming the transparent resin layer, and the thickness is 0.05 to 5 μm.
A degree is enough. When a matte surface is desired on the transfer-receiving body after the transfer, various particles may be mixed in the release layer or the surface of the release layer may be matted. By leaving the release layer on the substrate film side without transferring and transferring to the transfer receiving body, the unevenness of the interface between the release layer and the transparent resin layer formed thereon is transferred and transferred to the transfer receiving body. The surface of the outermost layer such as a transparent resin layer is matted to obtain a matte surface.

Next, the heat-sensitive adhesive layer 3 is a transparent layer in which fine particles are contained in a resin having good heat adhesion. As a resin having good thermal adhesion, for example, a thermoplastic resin such as an acrylic resin, a polyvinyl chloride resin, a polyvinyl acetate resin, a vinyl chloride-vinyl acetate copolymer, a polyester resin, and a polyamide resin can be used. The thickness of the heat-sensitive adhesive layer is about 0.1 to 10 μm. If it is too thin, the adhesive effect cannot be obtained, and if it is too thick, it is meaningless. The heat-sensitive adhesive layer 3 can be formed by the same coating means and printing means as those for forming the transparent resin layer.

The fine particles to be contained in the heat-sensitive adhesive layer include, in addition to inorganic fillers such as silica, alumina, calcium carbonate and talc, resin particles such as acrylic resin, fluororesin, polyethylene resin and polystyrene resin, or wax. Particles and the like can be used. Even if the surface is roughened by the inclusion of fine particles, if the roughening hinders thermal bonding, the adhesiveness is reduced. Therefore, the particle diameter of these fine particles is preferably 0.1 to 10 μm. When the thickness is less than 0.1 μm, the effect of reducing the coefficient of friction by roughening the surface of the heat-sensitive adhesive layer is small, and even when the thickness exceeds 10 μm, the surface roughness becomes too large in relation to the thickness of the heat-sensitive adhesive layer, The convex portion is not preferable because it becomes an obstacle to thermal bonding. On the other hand, if the content is too large, the fluidity of the heat-sensitive adhesive layer at the time of thermal softening is reduced, which is also an obstacle to thermal bonding, which is not preferable. As the silica, silica obtained by adjusting the porosity (internal surface area or pores) obtained by a wet method is preferable. As such silica, those commercially available from Fuji Silysia Chemical Ltd. under the trade names "Sylysia" and "Sylohobic" can be used. Among these silicas, those having an average particle diameter of about 1 to 10 μm are excellent in the effect of roughening the surface without being contained in a large amount, and as a result, without impairing the heat bonding and lowering the transparency. preferable. Further, in the case of fine particles having a shape close to a sphere, such as resin particles, if the size is larger than the thickness of the heat-sensitive adhesive layer, the convex portion is not preferable because it becomes an obstacle to the heat bonding at the time of transfer. However, it does not matter if it is deformed by heat at the time of transfer like wax particles.

The content of the fine particles should be within a range that does not impair the transparency and the adhesiveness to the object to be transferred, and is preferably 0.1 to 1 part by weight based on 100 parts by weight of the resin used for the heat-sensitive adhesive layer.
0 parts by weight. If the amount is less than 0.1 parts by weight, the effect of roughening the surface by causing irregularities on the surface cannot be sufficiently obtained.
If the amount exceeds 10 parts by weight, the transparency of the cover film is lowered, and the adhesiveness is lowered as described above. Specifically, for example, in the case of silica composed of the secondary aggregated particles, a preferable range is 1 to 3 parts by weight. In addition, when fine particles are contained, wrinkles are particularly likely to occur if there is a skew during transportation due to the relative relationship with the thermal transfer cover film when transferring to a large-sized object such as A4 or A3. As a result, the skew is corrected during conveyance, and the occurrence of wrinkles is suppressed. In addition, when stored in a roll state before using the thermal transfer cover film, an effect that blocking can be prevented can be achieved. In addition, in order to improve the slipperiness during transportation, it is possible to mix silicone wax as a lubricant in the outermost layer, such as the heat-sensitive adhesive layer or the back layer, but the silicone wax is used in the heat-sensitive adhesive layer. Even if it is mixed with the back layer, the back layer comes into contact with the heat-sensitive adhesive layer during storage in a roll state, so even if it is blended in the back layer, the adhesion will also be reduced due to the effect of silicone oil. It requires attention and is not preferred. However, in the present invention, since the improvement in the slipperiness is realized by the fine particles, a decrease in the adhesiveness does not occur. In addition, it is also possible to provide a back layer for imparting slip properties by providing appropriate slip on the heat-sensitive adhesive layer side, and the number of layers does not increase,
There is also an advantage that the number of steps is not increased. Further, it is particularly effective when the surface which needs to be provided with the slipperiness is the heat-sensitive adhesive layer side when transported by the printer.

The thermal transfer cover film of the present invention may be provided with a function of blocking ultraviolet rays in order to protect the transfer object from ultraviolet rays. For this purpose, as shown in FIG. 3, an ultraviolet ray blocking layer 5 for absorbing or blocking ultraviolet rays is newly provided, or one or both of a transparent resin layer and a heat-sensitive adhesive layer are transferred to a transfer layer to be transferred. Preferably, an ultraviolet absorber is contained therein. However, when an ultraviolet absorber is contained in a resin layer such as a transparent resin layer or a heat-sensitive adhesive layer, there is a limit to the content while maintaining the desired transparency, physical properties, etc. Despite this, a large UV blocking effect cannot be expected. Therefore, as a layer dedicated to blocking ultraviolet rays (and also functions as a protective layer), an ultraviolet absorber (hereinafter, referred to as a resin) formed by reacting a reactive ultraviolet absorber with a resin.
By using one or more resin-type ultraviolet absorbers), a large amount of (reactive) ultraviolet absorber can be contained, and a large ultraviolet blocking effect can be obtained. Further, as shown in FIG.
In addition to the layer structure on the side of the base film 1, it may be between the transparent resin layer 2 and the heat-sensitive adhesive layer 3 or between the base film 1 and the release layer 4. is there.

Examples of the reactive ultraviolet absorber include non-reactive ultraviolet absorbers such as salicylate-based, benzophenone-based, benzotriazole-based, substituted acrylonitrile-based, nickel-chelate-based and hindered amine-based ultraviolet absorbers. For the absorbent, for example, those having a reactive group such as an addition polymerizable double bond such as a vinyl group, an acryloyl group, or a methacryloyl group, or an alcoholic hydroxyl group, an amino group, a carboxyl group, an epoxy group, or an isocyanate group are used. I can do it. Further, in order to react and bond the reactive ultraviolet absorber into a resin type ultraviolet absorber, a compound having a reactive group corresponding to the above-mentioned various reactive groups is reacted. For example, when the reactive ultraviolet absorber has an addition-polymerizable double bond, as a compound having an addition-polymerizable double bond, for example, a conventionally known monomer, oligomer, resin such as a reactive polymer, Polymerize with UV absorber. When the reactive ultraviolet absorber has a reactive group such as an alcoholic hydroxyl group, an amino group, a carboxyl group, an epoxy group, and an isocyanate group, a heat having a reactive group capable of reacting with the reactive group. A reactive ultraviolet absorber is fixed to the thermoplastic resin by using a thermoplastic resin and, if necessary, using a catalyst.

The compound having an addition-polymerizable double bond to be copolymerized with a reactive ultraviolet absorber includes:
For example, any of conventionally known monomers, oligomers, prepolymers and the like may be used. For example, as the monomer, methyl (meth) acrylate [(meth) acrylate is,
Represents acrylate or methacrylate. The same applies hereinafter),
Ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, lauryl tridecyl (meth) Acrylate, tridecyl (meth) acrylate, serylstearyl (meth) acrylate, stearyl (meth) acrylate, ethylhexyl (meth) acrylate, octyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, acrylic acid, methacrylic acid , Hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) Acrylate, tert- butyl aminoethyl (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate.

Further, ethylene di (meth) acrylate, diethylene glycol (meth) acrylate, triethylene glycol (meth) acrylate, tetraethylene glycol (meth) acrylate, decaethylene glycol (meth) acrylate, pentadecaethylene (meth) acrylate, pentacon Reactor ethylene glycol (meth) acrylate, butylene di (meth) acrylate, allyl (meth) acrylate, trimethylolpropane tri (meth) acrylate, hexanediol di (meth) acrylate, tripropylene glycol di (meth) acrylate, pentaerythritol tetra (Meth) acrylate, pentaerythritol hexa (meth) acrylate, 1,6-hexanediol (meth) acrylate, Neopentyl glycol penta (meth) acrylate, phosphazene hexa (meth) acrylate.

The above-mentioned various monomers may be used as an oligomer. Further, a polyester acrylate based polymer of a polymer of the above-mentioned various monomers or a derivative thereof,
Acrylic reactive polymers such as epoxy acrylates can also be used. These monomers, oligomers, and acrylic reactive polymers may be used alone or as a mixture. As described above, by copolymerizing a monomer, an oligomer, an acrylic reactive polymer and a reactive ultraviolet absorber, a thermoplastic copolymer resin in which the reactive ultraviolet absorber is fixed by reaction can be obtained. In this copolymer resin,
10 to 90% by weight, preferably 30 to 90% by weight based on the total amount of the resin
It preferably contains 70% by weight of a reactive UV absorber. By using such a resin-type reactive ultraviolet absorber, an extremely large amount of the ultraviolet absorber can be contained in comparison with the case of a non-reactive ultraviolet absorber, and excellent ultraviolet shielding in a cover film to be transferred. An effect can be given. Note that the ultraviolet ray blocking layer may be formed of a resin type ultraviolet ray absorber alone, or may be mixed with another resin as needed. When the resin-type reactive ultraviolet absorber is a copolymer resin, the molecular weight is preferably about 5,000 to 300,000, and more preferably about 9,000 to 250,000. If the molecular weight is less than 5,000, sufficient toughness cannot be obtained due to poor film strength. Also, 300,00
If it exceeds 0, the viscosity increases and the handling becomes complicated.

The UV blocking layer 5 is formed by a known coating means such as a gravure coat, a gravure reverse coat, a roll coat or the like, or a print means, similarly to the formation of the transparent resin layer or the heat-sensitive adhesive layer. Can be. In the case where the ink layer region is provided alternately with the cover film region in a face-sequential manner, the coating is performed by a coating means capable of partial coating or a printing means such as gravure printing or screen printing. Further, the thickness of the ultraviolet blocking layer is about 0.5 to 5 μm, preferably 1 to 2 μm. If the thickness is too small, the effect of the ultraviolet absorbing ability cannot be obtained, and if the thickness is too large, the performance becomes excessive.

If the required performance is allowed, the content of the ultraviolet ray blocking layer is not increased, and there is a limit. Therefore, the effect of the resin type ultraviolet ray absorbent cannot be obtained. May be appropriately contained in the resin. Therefore, in addition to the constitution provided as an independent ultraviolet shielding layer, without providing an independent ultraviolet shielding layer, a salicylate-based, benzophenone-based or benzotriazole-based resin is used in one or both of the transparent resin layer and the heat-sensitive adhesive layer resin. ,
A conventionally known non-reactive ultraviolet absorber such as a substituted acrylonitrile type, a nickel chelate type and a hindered amine type may be contained.

The back layer 6 is a layer provided to provide heat resistance, lubricity, antistatic performance and the like required as required. To impart heat resistance, as a heat-resistant curable resin,
A urethane resin, a melamine resin, an epoxy resin, a silicone resin, or a thermoplastic resin if heat resistance is allowed can be used. For imparting lubricity, conventionally known various lubricants such as a phosphate ester-based surfactant and various conventionally known fillers such as silica, alumina and resin particles are contained. In the case of a thermal transfer cover film having an ink layer region, a back layer may be provided on the back of the base film in the ink layer region.

Next, the ink layer region in a form in which the cover film region and the ink layer region are alternately provided in a plane-sequential manner will be described. As described above, the ink layer region may be any of a sublimation transfer type, a fusion transfer type, and a combination type thereof.

When the coloring material layer in the ink layer region is a dye layer of a sublimation transfer type, the dye layer is formed by dispersing or dissolving a sublimable dye in a binder resin,
It may have a conventionally known configuration in which various additives are contained as necessary. For example, a cellulose resin such as ethyl cellulose, a polyvinyl acetal resin such as polyvinyl acetoacetal, or the like is used as the binder resin. The dye layer has a thickness of about 0.2 to 5 μm and is formed by a conventionally known coating method or printing method capable of partially forming in the longitudinal direction. When the color material layer in the ink layer region is a color material layer of a melt transfer type, the color material layer contains a wax component, a color material, and various additives appropriately added. A known configuration may be used. For example, as the wax component, resins such as carnauba wax, paraffin wax, polyethylene wax and fatty acid ester, and if necessary, a low-melting thermoplastic resin such as an ethylene-vinyl acetate copolymer are used. In this case, the thickness of the color material layer is 1 to 15
It is about μm, and is formed by a conventionally known coating method or printing method capable of partially forming in the longitudinal direction such as a hot melt coat or a gravure coat of an emulsion.

[0027]

EXAMPLES Hereinafter, the thermal transfer cover film of the present invention will be further described with reference to examples. Unless otherwise specified, “parts” means “parts by weight”. The ratio is based on weight.

Example 1 A thermal transfer cover film having the structure shown in FIG. 4 was produced as follows. First, a back layer coating solution having the following composition was coated on the entire surface of one side of a polyethylene terephthalate film (Lumirror, manufactured by Toray Industries, Ltd.) having a thickness of 6 μm as a base film by a gravure coating method. After heating and curing for days,
The same applies hereinafter) to form a back layer of 1.0 g / m ² .

Back layer coating liquid polyvinyl butyral resin 3.6 parts (Sekisui Chemical Co., Ltd., ESLEC BX-1) Polyisocyanate 8.4 parts (Dainippon Chemical Co., Ltd., Burnox D750) Acid ester surfactant 2.8 parts (Paisurf A208S, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) Talc (Microace P-3, manufactured by Nippon Talc Co., Ltd.) 0.6 parts Solvent (methyl ethyl ketone / toluene = 1) / 1) 190 copies

Next, a coating liquid for a release layer having the following composition, a coating liquid for a transparent resin layer,
And a heat-sensitive adhesive layer coating liquid were sequentially applied by a gravure coating method, and a release layer having an application amount of 0.4 g / m ² and an application amount of 2.
A transparent resin layer of 0 g / m ^2, to form a heat-sensitive adhesive layer of the coating amount 1.0 g / m ^2, to obtain a thermal transfer cover film of the present invention as a long strip.

Release Layer Coating Solution Polyvinyl Alcohol Resin 3 parts (Nippon Synthetic Chemical Co., Ltd., Gohsenol C-500) Polyurethane Resin 2 parts (Dainippon Chemical Co., Ltd., Hydran AP-40) Fluorescent brightening (Ciba-Geigy, Ubitex CF) 0.1 part Water 60 parts Ethyl alcohol 30 parts

Transparent resin layer coating liquid Acrylic resin (LP-45M, Soken Chemical Co., Ltd.) 20 parts Polyethylene wax 0.4 parts Fluorescent whitening agent (Ciba Geigy, Ubitex OB) 0.1 parts Methyl ethyl ketone / Toluene = 1/1 80 parts

Heat- sensitive adhesive layer coating liquid Vinyl chloride-vinyl acetate copolymer 20 parts (Denka vinyl 1000ALK, manufactured by Denki Kagaku Kogyo KK) Silica (Fuji Silysia Chemical Ltd., Sylysia 530) 0.6 part ( Average particle diameter 1.9 μm, surface area 500 m ² / g) methyl ethyl ketone / toluene = 1/1 40 parts

Example 2 A thermal transfer cover film was obtained in the same manner as in Example 1 except that the coating composition for the heat-sensitive adhesive layer was changed to the following composition.

Heat- sensitive adhesive layer coating liquid Vinyl chloride-vinyl acetate copolymer 20 parts (Denka vinyl 1000ALK, manufactured by Denki Kagaku Kogyo KK) Silica (Fuji Silysia Chemical Ltd., Sylysia 310) 0.6 part ( Average particle diameter 1.4 μm, surface area 300 m ² / g) methyl ethyl ketone / toluene = 1/1 40 parts

Example 3 A thermal transfer cover film was obtained in the same manner as in Example 1 except that the coating composition for the heat-sensitive adhesive layer had the following composition.

Heat- sensitive adhesive layer coating liquid Vinyl chloride-vinyl acetate copolymer 20 parts (Denka vinyl 1000ALK, manufactured by Denki Kagaku Kogyo Co., Ltd.) Silica (Silohobic 100, manufactured by Fuji Silysia Chemical Ltd.) 0.6 Parts (average particle size 1.4 μm, oil absorption 250) methyl ethyl ketone / toluene = 1/1 40 parts

Example 4 First, in order to obtain a thermal transfer cover film having an ink layer area (three colors of yellow, magenta and cyan, excluding black) as shown in FIG. 5, an ink for sublimation transfer having the following composition was used. It was adjusted.

Ink for forming ink layer (A) Yellow ink 5.5 parts of quinophthalone-based yellow dye 4.5 parts of polyvinyl butyral resin 4.5 parts (manufactured by Sekisui Chemical Co., Ltd., Eslec BX-1) methyl ethyl ketone / toluene = 1/190 Department

(B) Magenta ink The procedure was the same except that CIDisperese Red 60 was used in place of the yellow dye. (C) Cyan ink The same procedure was used except that CISolvent Blue 63 was used in place of the yellow dye.

Next, a dye layer to be a color material layer of each color of yellow, magenta, and cyan was printed on the base film having the back layer used in Example 1 by using each of the above-described inks in a plane-sequential manner. To form an ink layer region, and then, between the ink layer regions, a cover film region composed of a release layer, a transparent resin layer, and a heat-sensitive adhesive layer, as in Example 1, is formed by partial coating. A long-strip thermal transfer cover film with an ink layer having an ink layer region and a cover film region alternately repeated in the longitudinal direction was obtained. The size of each color in the ink layer region and the size of the cover film region are 150 mm in length (longitudinal direction) and 10 mm in width (perpendicular to the longitudinal direction).
0 mm.

Example 5 A thermal transfer cover film was obtained in the same manner as in Example 1 except that the coating composition for the heat-sensitive adhesive layer had the following composition.

Heat- sensitive adhesive layer coating liquid Vinyl chloride-vinyl acetate copolymer 20 parts (Denka vinyl 1000ALK, manufactured by Denki Kagaku Kogyo Co., Ltd.) Silica (Silohobic 100, manufactured by Fuji Silysia Chemical Ltd.) 0.6 Part (average particle diameter: 1.4 μm, oil absorption: 250) Resin-type ultraviolet absorber (UVA-635L, manufactured by BASF Japan Co., Ltd.) 5 parts Methyl ethyl ketone / toluene = 1/1 40 parts

(Example 6) In Example 1, after a release layer was coated and a transparent resin layer was coated, an ultraviolet shielding layer having a coating amount of 1.0 g / cm ² was coated with an ultraviolet shielding layer coating solution having the following composition. A heat transfer cover film was obtained in the same manner as in Example 1 except that the layer was also formed by coating.

UV blocking layer coating solution resin type UV absorber (UVA-635L, manufactured by BASF Japan Ltd.) 20 parts Methyl ethyl ketone / toluene = 1/80 parts

Comparative Example 1 A thermal transfer cover film was obtained in the same manner as in Example 1, except that the coating composition for the heat-sensitive adhesive layer had the following composition.

Heat- sensitive adhesive layer coating liquid Vinyl chloride-vinyl acetate copolymer 20 parts (Denka vinyl 1000ALK, manufactured by Denki Kagaku Kogyo KK) Methyl ethyl ketone / toluene = 1/1 40 parts

Comparative Example 2 A thermal transfer cover film was obtained in the same manner as in Example 1 except that the coating composition for the heat-sensitive adhesive layer had the following composition.

Heat- sensitive adhesive layer coating liquid Vinyl chloride-vinyl acetate copolymer (Denka vinyl 1000ALK, manufactured by Denki Kagaku Kogyo KK) 20 parts Silica (Fuji Silysia Chemical Ltd., Sylysia 530) 4 parts (Average particles) Diameter 1.9 μm, Surface area 500 m ² / g) Methyl ethyl ketone / toluene = 1/1 40 parts

(Preparation of Thermal Transfer Image-Receiving Sheet for Evaluation) A 150 μm thick synthetic paper (Yupo FRG-150, manufactured by Oji Yuka Synthetic Paper Co., Ltd.) was used as a base sheet. Apply the layer coating liquid with a bar coater,
A receptor layer having a coating amount of 4 g / m ² was formed to prepare a thermal transfer image receiving sheet.

Receptive layer coating liquid Vinyl chloride-vinyl acetate copolymer 20 parts (Electrical Chemical Industry Co., Ltd., Electrified Vinyl 1000A) Epoxy-modified silicone oil 1 part (Shin-Etsu Chemical Co., Ltd., X-22) 3000T) Methyl ethyl ketone / toluene = 1/1 80 parts

(Evaluation of Performance) The dye layer surface in the ink layer region of the thermal transfer cover film prepared in Example 4 was superimposed on the receptor layer surface of the thermal transfer image-receiving sheet, and the image data of the face photograph was subjected to color separation to obtain a printer. Thermal energy was applied by a thermal head to first form a full-color image on the thermal transfer image receiving sheet. The coefficient of friction between the receiving layer surface of the thermal transfer image-receiving sheet on which the image has been formed and the heat-sensitive adhesive layer surface of each of the cover film regions of Examples 1 to 5 and Comparative Examples 1 and 2 was measured using a tensile tester (Toyo Seiki Co., Ltd. ), Tensilon). The measuring method is as follows. The image receiving sheet is fixed on a horizontal table with the receiving layer surface facing upward, the heat-sensitive adhesive layer surface of the portion to be the cover film of the 100 mm-wide thermal transfer cover film is faced up, and a load of 200 mm is applied.
The thermal transfer cover film was pulled at 0 g at a pulling speed of 200 mm / min, and the dynamic friction coefficient was measured.

[0053]

[Table 1]

As shown in Evaluation Table 1, in each of the examples in which fine particles were contained in the resin of the heat-sensitive adhesive layer, the coefficient of friction was 0.65 in Comparative Example 1 which is a conventional thermal transfer cover film containing no fine particles. Therefore, both are reduced to 0.25 or less, and transferability and transparency are not impaired.
There was no possibility that the thermal transfer cover film and the image receiving paper were entangled with each other to cause a conveyance jam. However, when the content of the fine particles is too large as 20% as in Comparative Example 2, although the coefficient of friction is reduced, the transferability and transparency of the cover film are reduced, and the basic properties required for the cover film are satisfied. Did not.

[0055]

According to the present invention, fine particles are contained in the heat-sensitive adhesive layer and the surface thereof is roughened, so that the coefficient of friction is reduced due to the decrease in the contact area with the image receiving paper or the like as the transfer object. Therefore, a jam at the time of conveyance by the printer can be eliminated. Conventionally, the size of the transfer target is particularly A3
In the case of large size such as A4 or A4, if the transfer of the thermal transfer cover film or the image receiving paper is slightly skewed in the printer,
The cover film after transfer was easily wrinkled, but in the present invention, since the sliding property is improved, the skew is corrected during conveyance with Puritan and wrinkles are hardly formed, and wrinkles at the time of forming a cover film to a large size are reduced. The occurrence prevention effect is remarkable. Also,
It also has an effect of preventing blocking in a wound state before use.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of the thermal transfer cover film of the present invention.

FIG. 2 is a sectional view showing another embodiment of the thermal transfer cover film of the present invention.

FIG. 3 is a sectional view showing another embodiment of the thermal transfer cover film of the present invention.

FIG. 4 is a sectional view showing another embodiment of the thermal transfer cover film of the present invention.

FIG. 5 shows an example of the thermal transfer cover film of the present invention, in which the ink layer region has yellow, magenta, cyan,
An example of being partitioned into multiple black colors.

FIG. 6 is an explanatory diagram illustrating a conveyance jam in the printer.

[Explanation of symbols]

Reference Signs List 1 base film 2 transparent resin layer 3 heat-sensitive adhesive layer 4 release layer 5 ultraviolet blocking layer 6 back layer 7 cover film area 8 ink layer area 10, 10a to 10c thermal transfer cover film 10d also has an ink layer area for image formation Thermal transfer cover film 61 Platen roller 62 Thermal head 63 Roller 64 Thermal transfer cover film 65 Image receiving paper Y Yellow part of ink layer area M Magenta part of ink layer area C Cyan part of ink layer area Bk Black part of ink layer area

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B41M 5/38 B41M 5/26 101Z

Claims (6)

[Claims] 1. A heat transfer cover film comprising a base film, a transparent resin layer provided releasably, and a heat-sensitive adhesive layer provided on the surface thereof, wherein the heat-sensitive adhesive layer contains fine particles. . 2. The thermal transfer cover film according to claim 1, further comprising a release layer between the base film and the transparent resin layer. 3. The thermal transfer cover film according to claim 1, further comprising an ultraviolet blocking layer between the transparent resin layer and the heat-sensitive adhesive layer. 4. The thermal transfer cover film according to claim 1, wherein the heat-sensitive adhesive layer contains an ultraviolet absorbent. 5. The method according to claim 1, wherein a cover film area having a transparent resin layer and an ink layer area having at least one color material layer are provided on the same base film in a face-to-face order. The thermal transfer cover film according to any one of the preceding claims. 6. The thermal transfer cover film according to claim 5, wherein the color material layer has a dye layer of at least one color or more and a molten black layer in a plane-sequential manner.