JP3033843B2 - Composite thermal transfer sheet - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a composite thermal transfer sheet, and more particularly, to a composite thermal transfer sheet capable of forming a high-quality color image by a thermal transfer method.

(Prior art and its problems) Conventionally, various thermal transfer methods are known. Among them, a sublimable dye is used as a recording agent, and this is carried on a base film such as paper or plastic film, and a thermal transfer sheet is formed. A method of forming various full-color images on an image receiving sheet such as paper or a plastic film provided with a dye receiving layer has been proposed. In this case, a thermal head of a printer is used as a heating means, and a large number of color dots of three or four colors are transferred to the image receiving sheet by heating for a very short time, and a full-color image of an original is formed by the multicolored dots. That is to reproduce.

The image-receiving sheet on which an image can be formed by the above method is limited to a dye-dyeing plastic sheet or a paper provided with a dye-receiving layer in advance, and an image cannot be directly formed on ordinary plain paper. There is. As a method for solving such a problem, when an image is to be formed on a ready-made image receiving sheet such as plain paper, as a method of easily forming a dye receiving layer only on a necessary portion, a receiving layer transfer sheet is used. It is known (see, for example, JP-A-62-264994). As a method for further simplifying the operation, yellow, cyan, magenta and, if necessary, black dye layers are sequentially formed on the surface of the long base film, and a transfer receiving layer is further formed on the same base film surface. There has also been proposed a composite thermal transfer sheet in which a receiving layer is first transferred to an image receiving sheet, and then a dye of each color is transferred to the receiving layer to form a full-color image. In this case, a release agent is added in the receiving layer in order to prevent adhesion between the receiving layer and the dye layer when an image is formed after transferring the receiving layer.

However, as a result of the release agent being added to the receiving layer, the adhesiveness to the material to be transferred and the foil cutting properties may be insufficient during the transfer of the receiving layer.

In some cases, it is required to provide a protective layer on the image surface after forming an image on the transfer receiving layer. In this case, however, it is said that the adhesion of the protective layer is insufficient and good image protection cannot be performed. There's a problem.

Therefore, an object of the present invention is to solve the above conventional problems, transferability of the receiving layer, foil cutting properties, peelability at the time of image formation,
An object of the present invention is to provide a composite thermal transfer sheet which is excellent in the adhesion of a protective layer and can form a high quality color image.

(Means for Solving the Problems) The above object is achieved by the present invention described below. That is,
According to the present invention, (1) one or a plurality of peelable dye-receiving layers, one or more color dye layers, and a transferable protective layer are provided on one surface of a long base film in a sequential manner. Wherein the dye layer contains a release agent component in the layer and the receptor layer contains substantially no release agent component.

(Function) By allowing the dye layer to contain the release agent component and substantially not containing the release layer component in the receiving layer, the transferability of the receiving layer, the cutting property of the foil, the releasability at the time of image formation, and the protective layer Provided is a composite thermal transfer sheet having excellent adhesion and the like and capable of forming a high-quality color image.

Preferred Embodiment Next, the present invention will be described in more detail with reference to preferred embodiments.

The composite thermal transfer sheet of the present invention has a dye layer 2 of one or more colors, for example, yellow (Y), on one surface of a long base film 1, as schematically shown in FIG. A magenta (M), cyan (C) and, if necessary, a black (not shown) dye layer, one or a plurality of peelable dye-receiving layers 3 and a transferable protective layer 4 are provided in a plane sequence. I have.

As the substrate film used in the present invention, the same substrate film as used in the conventional thermal transfer sheet can be used as it is, and other materials can be used without any particular limitation.

Specific examples of the preferred base film include, for example, thin paper such as glassine paper, condenser paper, and paraffin paper, polyester, polypropylene, cellophane, polycarbonate, cellulose acetate, polyethylene, polyvinyl chloride, polystyrene, nylon, polyimide, and polyvinylidene chloride. And a base film in which these are combined with a plastic such as an ionomer or the above-mentioned paper.

The thickness of the base film can be appropriately changed depending on the material so that the strength and heat resistance are appropriate, but the thickness is preferably 3 to 100 μm.

The dye layer formed on the surface of the base film as described above,
This is a layer in which a dye is supported by an arbitrary binder resin. As the dye to be used, any dye conventionally used in a thermal transfer sheet can be effectively used in the present invention, and is not particularly limited. For example, some preferred dyes include MS Red G, Macrolex Red Viole as red dyes.
t R, Ceres Red7B, Samaron Red HBSL, Resolin Red F3
BS, etc., and as the yellow dye, Holon Brilliant Yellow 6GL, PTY-52, Macrolex Yellow 6G, etc., and as the blue dye, Kayaset Blue 714, Waxolin Blue AP-FW , Holon Brilliant Blue SR, MS Blue 100 and the like.

As the binder resin for supporting the dye as described above, any conventionally known binder resin can be used, and preferred examples thereof include ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxycellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, and vinegar. Cellulose resins such as cellulose butyrate, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, polyvinyl pyrrolidone, vinyl resins such as polyacrylamide, polyester and the like, among these, cellulose, acetal, Butyral type and polyester type are heat resistant,
It is preferable from the viewpoint of dye transferability and the like.

Further, in the dye layer, various conventionally known additives may be included as necessary.

Such a dye layer is preferably prepared by adding the above-mentioned sublimable dye, a binder resin and other optional components in an appropriate solvent and dissolving or dispersing each component to prepare a dye layer forming paint or ink. Is formed on the above-mentioned base film by applying and drying it in a plane-sequential manner.

The dye layer thus formed has a thickness of about 0.2 to 5.0 μm, preferably about 0.4 to 2.0 μm, and the sublimable dye in the dye layer accounts for 5 to 90% by weight of the weight of the dye layer, preferably Is
Suitably it is present in an amount of from 10 to 70% by weight.

In one embodiment of the present invention, a release agent is added to the ink for forming the dye layer when forming the dye layer. In another example, a release agent layer may be formed on the surface after forming the dye layer. Examples of these release agents include silicone oil, phosphate ester surfactants, fluorine surfactants, and the like.
Silicone oil is preferred. As the silicone oil, a modified silicone oil such as epoxy-modified, alkyl-modified, amino-modified, carboxyl-modified, alcohol-modified, fluorine-modified, alkylaralkyl-polyether-modified, epoxy / polyether-modified, or polyether-modified is preferred.

One or more release agents are used.
When the release agent is added to the dye layer, the amount is preferably 0.5 to 30 parts by weight based on 100 parts by weight of the resin for forming the dye layer.
If the addition amount is not satisfied, problems such as fusion of the thermal transfer sheet and the dye receiving layer or reduction in printing sensitivity may occur. By adding such a release agent to the dye layer, the release agent bleeds out on the surface of the dye layer to form a release layer.

Instead of using the above-mentioned release agent, a binder modified with a release segment such as a silicone compound, a fluorine compound or a long-chain aliphatic compound can be used as a resin used for forming the dye layer.

The dye receiving layer formed on the surface of the base film is for receiving the sublimable dye transferred from the thermal transfer sheet after transferring to an arbitrary image receiving sheet and maintaining the formed image.

The dye receiving layer is provided on the dye layer in a plane-sequential manner. Although the relationship with the dye layer is not particularly limited, for example, the receptor layer YMCBk
The order of the MCBk receiving layer receiving layer, the order of the receiving layer Y receiving layer M receiving layer C receiving layer Bk receiving layer and the like can be mentioned.

Prior to the formation of the receiving layer, a release layer is preferably formed on the surface of the base film. Such a release layer is formed from a release agent such as a silicone resin, a fluorine resin, an acrylic resin, a water-soluble resin, polyamide, polyester, or polyurethane. The method of formation may be the same as the method of forming the receiving layer described below,
A thickness of about 0.01 to 5 μm is sufficient. If a matte receiving layer is desired after transfer, the release layer can be made into a matte surface by incorporating various particles in the release layer or using a base film having a release layer side surface matted. . Needless to say, when the base film has an appropriate peeling property, the release layer need not be formed.

Examples of the resin for forming the dye receiving layer include polyolefin resins such as polypropylene, halogenated polymers such as polyvinyl chloride and polyvinylidene chloride, vinyl polymers such as polyvinyl acetate and polyacrylester, polyethylene terephthalate, and poly (ethylene terephthalate). Polyester resins such as butylene terephthalate, polystyrene resins, polyamide resins, copolymer resins of olefins such as ethylene and propylene with other vinyl monomers, ionomers, cellulose resins such as cellulose diacetate, and polycarbonate. Particularly preferred are vinyl resins and polyester resins.

The receiving layer, on one side of the base film, a resin obtained by adding the necessary additives to the resin as described above, dissolved in an appropriate organic solvent, or dispersed in an organic solvent or water, For example, it is formed by applying and drying by a forming means such as a gravure printing method, a screen printing method, and a reverse roll coating method using a gravure plate.

The dye-receiving layer formed as described above may have any thickness, but generally has a thickness of 0.5 to 10 μm. Further, such a dye receiving layer is preferably a continuous coating, but may be formed as a discontinuous coating using a resin emulsion or a resin dispersion.

Further, a heat-sensitive adhesive layer can be provided on the surface of the receiving layer in order to improve the transferability of these layers.
These heat-sensitive adhesive layers are coated, for example, with a solution of a resin having good adhesiveness when heated, such as an acrylic resin, a polyvinyl chloride resin, a polyvinyl acetate resin, a vinyl chloride-vinyl acetate copolymer resin, and a polyester resin. By drying, it is preferably formed to a thickness of about 0.1 to 10 μm.
In addition, this layer may include a cushioning agent such as a foaming agent for imparting cushioning properties to the transferred receiving layer, and an additive such as titanium oxide or calcium carbonate for improving hiding properties and whiteness. You can also.

Further, in the embodiment of the present invention, the protective layer 4 is provided in a face-sequential manner after the dye layer. The protective layer 4 is made of various resins excellent in friction resistance, chemical resistance, transparency, hardness, etc., for example, polyester resin, polystyrene resin, acrylic resin, polyurethane resin, acrylic urethane resin, silicone-modified resin of these resins, A mixture of each of these resins is exemplified. Further, for the purpose of preventing the surface from being damaged, additives such as a filler, a wax and the like, an ultraviolet absorber, an infrared absorber, a fluorescent whitening agent and the like can be added to the protective layer. The thickness of the protective layer 4 is preferably about 0.1 to 20 μm.

Further, on the surface of the protective layer, a heat-sensitive adhesive layer similar to that described above can be provided to improve the transferability of these layers.

The image receiving sheet on which the receiving layer is transferred by using the receiving layer transfer sheet as described above is not particularly limited, and may be any sheet such as plain paper, high quality paper, tracing paper, plastic film, and the like. Typically, cards, postcards, passports, stationery, report paper, notes,
Any material such as a catalog may be used, and it is particularly applicable to plain paper and rough paper having a coarse surface.

The transfer method of the receiving layer or the protective layer may be a general printer equipped with a thermal head for thermal transfer, a hot stamper for a transfer foil, a heat roll, or the like, which can be heated to a temperature at which the receiving layer or the adhesive layer is activated. May be used.

As a method for forming an image, any of conventionally known means can be used. For example, a thermal printer (for example,
Hitachi, Ltd., manufactured by the video printer VY-100) a recording device such as by controlling the recording time, fully achieve the intended object by applying heat energy of about 5 to 100 mJ / mm ² You can do it.

(Examples) Next, the present invention will be described more specifically with reference to examples and comparative examples. In the following description, parts and% are based on weight unless otherwise specified.

Example 1 A coating solution for a receiving layer having the following composition at a width of 30 cm and an interval of 120 cm on a surface of a 4.5 μm-thick polyethylene terephthalate film (manufactured by Toray Industries, Inc.) having a heat-resistant lubricating layer formed on the back surface. Was applied by a bar coater at a rate of 3.0 g / m ² when dried, temporarily dried with a drier, and dried in an oven at 100 ° C. for 30 minutes to form a coating.

Composition of coating solution for receptor layer Vinyl chloride / vinyl acetate copolymer resin (# 1000A, manufactured by Denki Kagaku Co., Ltd.) 100 parts Methyl ethyl ketone / toluene (1/1 by weight) 500 parts Subsequently, an ink for dye layer having the following composition was prepared. It was prepared and applied by a gravure coater such that the dry coating amount was 30 g / m ² and the dry coating amount was 1.0 g / m ² on the surface of the base film where the receiving layer was not formed.

Ink composition for dye layer: Disperse dye (Kayaset Blue 714, Nippon Kayaku Co., Ltd.)
5.5 parts Polyvinyl butyral resin (S-REC BX-1, manufactured by Sekisui Chemical Co., Ltd.) 4.5 parts Release agent (KF-96, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.5 parts Methyl ethyl ketone / toluene (weight ratio 1/1) 89.0 parts In the same manner, the yellow thermal transfer sheet was treated with a yellow disperse dye (Macrolex Yellow 6G, manufactured by Bayer AG, CIDisp).
erese Yellow 201) and a magenta thermal transfer sheet was formed using a magenta disperse dye (CIDisperese Red 60).

Subsequently, the following coating liquid was applied at a solid content of 3.0 / m ^{2 to} a width of 30 cm and dried to form a transferable protective layer, thereby obtaining a composite thermal transfer sheet of the present invention.

Ink composition for protective layer Acrylic resin (BR-83, manufactured by Mitsubishi Rayon Co., Ltd.) 20 parts Polyethylene wax 1 part Methyl ethyl ketone / toluene (weight ratio 1/1) 80 parts The receiving layer surface of the composite thermal transfer sheet and plain paper Using a thermal head, the receiving layer was transferred over the entire surface under the conditions of an output of 1 W / dot, a pulse width of 0.3 to 0.45 msec., And a dot density of 3 dots / mm. Was subjected to color separation to print a yellow signal, and a yellow dye layer was superposed to form a yellow image. Further, a magenta dye and a cyan dye were similarly transferred to the image area obtained above by a magenta signal and a similar cyan signal to form a full-color image, and a protective layer was further transferred to the surface thereof.

Examples 2 to 5 Images were formed in the same manner as in Example 1 except that the release agents in Table 1 were used instead of the release agents in Example 1.

Comparative Example 1 An image was formed in the same manner as in Example 1 except that no releasing agent was added to the dye layer in Example 1 and the following releasing agent was added to the ink for the receiving layer.

Epoxy-modified silicone (KF-393, Shin-Etsu Chemical Co., Ltd.) 3 parts Amino-modified silicone (X-22-343, Shin-Etsu Chemical Co., Ltd.) 3 parts Comparative Example 2 Ink for dye layer in Example 1 An image was formed in the same manner as in Example 1 except that no release agent was added.

The results shown in Table 2 below were obtained from the results obtained in the above Examples and Comparative Examples.

(Effects) According to the present invention as described above, the dye layer contains a release agent component, and the receptor layer does not substantially contain a release agent component. The present invention provides a composite thermal transfer sheet which is excellent in peeling property at the time, adhesion of a protective layer, etc., and can form a high quality color image.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating a cross section of the composite thermal transfer sheet of the present invention. 1: Base film, 2: Dye layer, 3: Dye receiving layer, 4: Transferable protective layer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-17089 (JP, A) JP-A-63-170091 (JP, A) JP-A-1-200990 (JP, A) JP-A-2- 141289 (JP, A) JP-A-59-127798 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41M 5/38-5/40

Claims (4)

(57) [Claims] An elongate base film is provided on one side thereof with one or more peelable dye-receiving layers, one or more color dye layers and a transferable protective layer in a face-sequential manner. In the composite thermal transfer sheet, the dye layer has a release agent component, and the receiving layer contains substantially no release agent component. 2. The composite thermal transfer sheet according to claim 1, wherein a release agent component is contained in the dye layer. 3. The composite thermal transfer sheet according to claim 1, wherein the binder of the dye layer has a releasable segment. 4. The composite thermal transfer sheet according to claim 1, wherein the dye layer comprises at least three colors of yellow, magenta and cyan.