JP3336480B2 - Dye receiving layer transfer sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dye receiving layer transfer sheet for thermal transfer recording , and more particularly to a dye receiving layer transfer sheet capable of forming a high quality color image by a thermal transfer method.

[0002]

2. Description of the Related Art Conventionally, various thermal transfer recording methods are known. Among them, a thermal transfer sheet in which a dye layer containing a sublimable dye is formed on a support such as a polyester film is used. A sublimation transfer recording method of forming a dye image on a recording material by heating with a heating medium such as a laser is used as information recording means in various fields. According to this method, a large number of color dots of three or four colors can be transferred onto a recording material by heating for a very short time, and a full-color image of a document can be expressed. Because it is clear and excellent in transparency, it has excellent reproducibility and gradation of intermediate colors,
High quality images comparable to full color photographic images can be formed.

However, a recording material on which an image can be formed by a sublimation transfer recording method is a plastic sheet having a dye-dyeing property or a dye-receiving layer having a dye-dyeing property provided on the recording material in advance. However, there is a problem that an image cannot be directly formed on a metal sheet or glass as well as ordinary paper. In order to solve such problems, a receiving layer transfer sheet for forming a dye receiving layer on a recording material has been used. In this method, a dye receiving layer is provided on a base material so that the dye receiving layer can be peeled off. By heating an arbitrary area from the back side of the film with a thermal head or the like, the receiving layer is formed only on a required area on the recording material. Is transferred to
An image can be formed on the recording material having the receiving layer formed thereon by a sublimation transfer method.

In this receiving layer transfer sheet, the receiving layer of the non-heated portion remains on the receiving layer transfer sheet side, and only the receiving layer heated by the thermal head from the back side of the film is transferred onto the recording material. As such, a receiving layer must be formed on the substrate. In order to facilitate the peeling of the receiving layer from the substrate, a receiving layer transfer sheet in which a release resin layer is provided between the substrate and the receiving layer as disclosed in JP-A-4-135793, As in 165553, a receiving layer transfer sheet in which a release agent is further contained in a release layer has been proposed. However, if the release property of the release layer is too high, there is a problem of a tail fin that the receiving layer of the non-heated portion is transferred onto the recording material. However, if the releasability is too low, the receiving layer and the release layer do not peel off, causing jamming due to poor peeling at the time of printing. It is a serious problem.

[0005]

Therefore, when a resin having a glass transition point of 120 ° C. or more and 160 ° C. or less is used as the resin of the release layer, the release layer and the receiving layer are properly adhered to each other in the non-heated portion. Therefore, the receiving layer did not peel off from the release layer. In addition, even when heated, the resin having a glass transition point of 120 ° C. or more and 160 ° C. or less did not significantly increase the adhesion, so that the receiving layer could be easily peeled off from the release layer. The glass transition point is between 120 ° C and 160 ° C
Since the following resins have high crystallinity, their solubility in general-purpose solvents is poor, and solvents such as toluene and methyl ethyl ketone cannot be used as solvents during coating. Therefore, when a solvent having a high boiling point such as dimethylformamide or cyclohexane was used, the resin was dissolved, but a large amount of the solvent remained in the release layer under normal drying conditions, and the receiving layer formed thereon was It was found that it was difficult to peel off during storage.

Accordingly, the present invention solves the above-mentioned problems of the prior art, and can transfer a dye receiving layer only in a desired area without abnormal transfer such as jamming even in continuous printing under a high temperature environment. An object of the present invention is to provide a dye receiving layer transfer sheet for thermal transfer recording .

[0007]

In the present invention, a release layer is formed on one side of a substrate, and a releasable dye-receiving layer is formed on the release layer . In the dye receiving layer transfer sheet, the release layer has a glass transition point of 12
0 ° C or higher and 160 ° C or lower resin and glass transition point of 50 ° C
The above problem is solved by containing a resin having a temperature of at least 120 ° C.

[0008]

The resin having a glass transition point of not less than 120 ° C. and not more than 160 ° C. retains the dye receiving layer at room temperature and does not greatly increase the adhesion even when heated. Area control is easy. Also,
By adding a resin having a glass transition point of 50 ° C. or more and less than 120 ° C., the ratio of the low-boiling solvent in the ink can be increased, and the solvent in the release layer can be easily dried.

Hereinafter, the present invention will be described in detail. (Substrate) The substrate has a role of holding the dye-receiving layer, and since heat is applied at the time of thermal transfer, it is desirable that the substrate has a mechanical strength that does not hinder handling even in a heated state. The material of such a substrate is not particularly limited,
The same substrate as that used in the conventional thermal transfer sheet can be used as it is. For example, condenser paper, glassine paper, tissue paper such as paraffin paper, or polyester, polyacrylate, polycarbonate, polyurethane, polyimide, polyetherimide,
Cellulose derivatives, polyethylene, ethylene-vinyl acetate copolymer, polypropylene, polystyrene, acrylic, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl butyral, nylon, polyetheretherketone, polysulfone, polyethersulfone, tetrafluoroethylene -Perfluoroalkyl vinyl ether, polyvinyl fluoride, tetrafluoroethylene-ethylene, tetrafluoroethylene-hexafluoropropylene, polychlorotrifluoroethylene, polyvinylidene fluoride and the like, and films thereof. A laminate of paper may be used.

The thickness of these substrates can be appropriately changed depending on the material so that the strength, heat resistance and the like are appropriate, but it is preferably about 3 to 100 μm. Further, when the adhesion between the base material and the layer provided thereon is poor, it is preferable to apply a primer treatment or a corona discharge treatment to the surface, and particularly to the back side, to prevent fusion of the thermal head and run. In order to improve the removability, it is preferable to form a releasable heat-resistant lubricating layer in advance. The release heat-resistant lubricating layer can be formed from a release agent such as a curable silicone oil, a curable silicone wax, a silicone resin, a fluororesin, or an acrylic resin.

(Release Layer) The release layer in the present application has a glass transition point of 120 ° C. or higher and 1
A resin having a temperature of 60 ° C. or less and a glass transition point of 50 ° C. or more and 120
It is composed of a resin having a temperature of less than ° C. Glass transition point is 1
Examples of the resin having a temperature of 20 ° C. or more and 160 ° C. or less include polyurethane resins, polysulfone resins such as polyether sulfone, and Udel polysulfone. On the other hand, examples of the resin having a glass transition point of 50 ° C. or higher and lower than 120 ° C. include polyvinyl acetal, polyvinyl butyral, an acrylic resin, a cellulose resin, and polycarbonate.

The above glass transition point is 50 ° C. or more and 120 ° C.
It is necessary to add a resin having a glass transition point of not less than 120 ° C. and not more than 16 so as not to affect the performance of the release layer.
The resin having a glass transition point of 50 ° C. or more and less than 120 ° C. with respect to 100 parts by weight of the resin at 0 ° C. or less may be in the range of 10 to 100 parts by weight. Glass transition point of 50 ° C or higher 12
If the amount of the resin having a temperature of less than 0 ° C. is less than 10 parts by weight, the solvent in the release layer is difficult to dry. When a dye receiving layer is formed thereon, the residual solvent of the release layer has an adverse effect on the dye receiving layer, and the releasability between the release layer and the dye receiving layer is reduced,
Even the dye receiving layer of the portion to be transferred may remain on the transfer sheet side of the dye receiving layer without being transferred. In addition, a resin having a glass transition point of 50 ° C. or more and less than 120 ° C. is 1
If the amount is more than 00 parts by weight, the releasability between the release layer and the dye-receiving layer during heating is reduced, and it becomes difficult to control the transferability.

The release layer is formed by dissolving the above-mentioned resin in a solvent and applying it on a substrate. A resin having a glass transition point of 120 ° C. or more and 160 ° C. or less has high crystallinity. ,
Even if only ordinary solvents such as toluene and methyl ethyl ketone are used, the resin does not dissolve. Therefore, dimethylformamide, dimethylsulfoxide (DM
SO) and cyclohexanone have a glass transition point of 1
A solvent capable of dissolving the resin having a temperature of 20 ° C. or more and 160 ° C. or less is used. These solvents have a very high boiling point of 130 to 150 ° C., and have a drying ability with a normal gravure coater or the like.
In some cases, it cannot be dried sufficiently. In addition to the above-mentioned solvents, ordinary solvents such as toluene and methyl ethyl ketone can be mixed and used within a range in which the resin dissolves. The mixing ratio at this time is such that the glass transition point is 12
The other solvent is 10 to 200 parts by weight based on 100 parts by weight of a solvent capable of dissolving a resin having a temperature of 0 ° C or more and 160 ° C or less.

(Dye-Receiving Layer) A dye-receiving layer provided on the release layer receives a sublimation dye transferred from a thermal transfer sheet after being transferred onto an arbitrary recording material, and forms a formed image. It is for maintaining. As the resin for forming the dye receiving layer, for example, a polyolefin resin such as polypropylene, polyvinyl chloride, a vinyl chloride-vinyl acetate copolymer, a halogenated polymer such as polyvinylidene chloride, polyvinyl acetate,
Ethylene-vinyl acetate copolymer, vinyl polymer such as polyacrylester, polyester resin such as polyethylene terephthalate, polybutylene terephthalate, polystyrene resin, polyamide resin, copolymer of olefin such as ethylene and propylene with other vinyl monomers Polymeric resins, ionomers, cellulose resins such as cellulose diacetate, polycarbonate resins, polyvinyl acetal resins, polyvinyl alcohol resins and the like can be mentioned, and particularly preferred are vinyl resins, and polyester resins. .

It is preferable that a release agent is mixed and used in the dye receiving layer. Examples of the release agent include silicone oil, phosphate ester-based lubricant, and fluorine-based lubricant. Epoxy-modified, amino-modified, alkyl-modified, carboxyl-modified, alcohol-modified, fluorine-modified, alkylaralkyl Modified silicone oils such as polyether-modified, epoxy / polyether-modified, and polyether-modified are preferred. One or more of the above release agents are used, and the amount of the release agent is preferably 0.5 to 30 parts by weight based on 100 parts by weight of the resin for forming the dye receiving layer. If this range is not met,
Problems such as fusion between the thermal transfer sheet and the dye receiving layer or reduction in printing sensitivity may occur. By adding such a releasing agent, the releasing agent bleeds out to the surface of the dye receiving layer after transfer, and the releasing property is provided on the surface of the dye receiving layer.

In order to improve the whiteness of the dye receiving layer and further enhance the sharpness of the transferred image, titanium oxide, zinc oxide,
Pigments and fillers such as kaolin clay, calcium carbonate, and finely divided silica can be added to the dye receiving layer.

The above-mentioned dye-receiving layer is prepared by dissolving a resin obtained by adding necessary additives to a suitable organic solvent, or dispersing a dispersion in an organic solvent or water by, for example, gravure printing or screen printing. And coating and drying by a forming means such as 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 1 to 50 μm.
Also, the dye receiving layer is preferably a continuous coating layer,
A discontinuous coating may be formed using a resin emulsion or a resin dispersion.

(Adhesive Layer) It is preferable to provide an adhesive layer on the surface of the dye receiving layer for improving the transferability of the dye receiving layer. For these adhesive layers, for example, known pressure-sensitive adhesives, heat-sensitive adhesives, or pressure-sensitive adhesives are used. In particular, a heat-sensitive or pressure-sensitive adhesive which has no adhesiveness at normal temperature or normal pressure and exhibits an adhesive force only when heated or pressed is preferable.In this case, when the obtained dye receiving layer transfer sheet is wound in a roll shape Also, blocking between the base material and the adhesive layer hardly occurs. The heat-sensitive or pressure-sensitive adhesive is, for example, a resin having a relatively low melting point such as a polyamide resin, an acrylic resin, a vinyl chloride resin, a vinyl chloride-vinyl acetate copolymer resin, and a polyester resin,
Alternatively, these resins are obtained by mixing a microcapsulated pressure-sensitive adhesive with the resin, and exhibit adhesiveness by heating, or break the microcapsules by applying pressure to exhibit excellent adhesiveness. As the pressure-sensitive adhesive, a known pressure-sensitive adhesive of rubber type, acrylic type, silicone type or the like is used. The thickness of the formed adhesive layer is preferably 0.5 to 1
It is about 0 μm.

(Intermediate Layer) Further, in the present invention, between the dye receiving layer and the adhesive layer,
An intermediate layer can be provided. Examples of the material constituting the intermediate layer include polyurethane resin, acrylic resin, polyethylene resin, butadiene rubber, and epoxy resin. The thickness of the intermediate layer is preferably about 2 to 10 μm, and the formation method may be the same as that of the dye receiving layer.
White pigment, fluorescent whitening agent in the adhesive layer and the intermediate layer,
Alternatively, bubbles (foaming agent) can be contained. These white pigments and fluorescent whitening agents are added to improve the whiteness of the dye receiving layer after transfer, or to obtain a good color image recording by hiding the color of the recording material, In addition, the bubbles (foaming agent) have a function of giving a good cushioning property to the dye receiving layer. As a method of incorporating these additives, the additives may be contained in the coating liquid used when forming each layer.

In the dye-receiving layer transfer sheet for thermal transfer recording of the present invention, a long base film is used as a base material, and the following dye layer is formed on the surface of the long film in the order of the dye receiving layer. It can also be formed. Such a dye layer is a layer in which a sublimable 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, dyes for magenta include MS RedG and Macrolex Red.
Violet R, Ceres Red7B, Sama
ron RedHBSL, Resolin RedF3
BS, etc., and as a yellow dye, Holon Brilliant Yellow 6GL, PTY-52, Macrolex Yellow 6G, etc., and as a cyan 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 of conventionally known binder resins can be used. Preferred examples thereof include ethylcellulose, hydroxyethylcellulose, ethylhydroxycellulose, hydroxypropylcellulose, methylcellulose and acetate. Cellulose resins such as cellulose and cellulose acetate butyrate,
Polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, polyvinyl pyrrolidone, vinyl resins such as polyacrylamide, polyester and the like, among these, cellulose,
Acetal-based butyral-based and polyester-based ones are preferred from the viewpoint of heat resistance, dye transferability, and the like. Further, in the dye layer, various other 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 paint or ink for forming a dye layer. Then, it is formed by applying and drying the above-mentioned substrate film in a face-to-face order. The dye layer thus formed has a thickness of 0.2 to 5.0 μm, preferably about 0.4 to 2.0 μm, and the sublimable dye in the dye layer has a thickness of 5 to 5% of the weight of the dye layer. ~ 90% by weight,
It is preferably present in an amount of 10 to 70% by weight.

In the thermal transfer recording dye-receiving layer transfer sheet of the present invention, a protective layer may be formed in a surface-sequential manner with the dye-receiving layer. The protective layer is made of polyester, polystyrene, acrylic resin, polyurethane, acrylic urethane, or a silicone-modified resin of these resins alone or in a mixture. The dye-receiving layer is transferred to a recording material, After forming an image with the dye in the layer, the image is further transferred thereon to enhance the storage stability of the dye image, such as light resistance and fingerprint resistance. This protective layer forms a release layer on the substrate of the dye receiving layer transfer sheet, and is formed so as to be releasable thereon. As a material of the release layer,
In the present invention, a release layer containing a resin having a glass transition point of 120 ° C. or more and 160 ° C. or less and a resin having a glass transition point of 50 ° C. or more and less than 120 ° C. can be used. The protective layer formed on the release layer of the present invention can be reliably transferred only to a desired area as in the transfer of the dye receiving layer.

A transferable resin layer including a dye receiving layer and a dye layer,
Although the relationship with the protective layer is not particularly limited, for example, a transferable resin layer in which one unit includes a dye receiving layer → Y → M → C → Bk →
The order of the protective layers is generally, but not limited to.
The dye layers of the respective hues are usually provided in the same area. However, the transferable resin layer and the protective layer including the dye receiving layer may be different depending on the type of the recording material and the durability required for the image. In some cases, the transfer is performed more than once, and therefore, a larger area can be formed.

The transfer material on which the dye-receiving layer is transferred as described above is not particularly limited, and may be any material such as plain paper, woodfree paper, tracing paper, plastic film, metal, glass, and the like. In terms of shape,
Any type of card, postcard, passport, stationery, report paper, notebook, catalog, etc. may be used, and it is particularly applicable to plain paper and rough paper with a rough surface.

As a means for applying thermal energy for transferring the dye receiving layer or the protective layer, any conventionally known heating and pressurizing means such as a thermal head, a hot stamper, and a hot roll can be used. The recording time is controlled by a recording device such as a video printer VY-100 manufactured by Hitachi, Ltd.
By applying heat energy of about 100 mJ / mm ² , the intended purpose can be sufficiently achieved.

[0027]

EXAMPLES Examples using the present invention will be described below in detail. (Example 1) A 6 μm-thick polyethylene terephthalate film (Diafoil, Lumirror) transparent substrate sheet was coated with a coating liquid for a release layer composed of the following composition, and then dried to release the release layer. Was formed. Thereafter, the dye receiving layer and the adhesive layer were applied by a roll coating method, and dried at 110 ° C. for 2 minutes. Coating liquid for release layer Polyurethane varnish (Dai Nippon Ink Co., Ltd., Crisbon 9004) Glass transition point 130 ° C 100 parts by weight Polyvinyl acetal (Sekisui Chemical Co., Ltd., Eslek KS-5) Glass transition point 110 ° C 100 parts by weight Methyl ethyl ketone / DMF = 1/1 400 parts by weight Coating liquid for dye receiving layer Vinyl chloride vinyl acetate copolymer (VYHD, manufactured by Union Carbide) 100 parts by weight Amino-modified silicone (manufactured by Shin-Etsu Chemical Co., Ltd.) KS-343) 3 parts by weight Epoxy-modified silicone (KF-393, manufactured by Shin-Etsu Chemical Co., Ltd.) 3 parts by weight Methyl ethyl ketone / toluene = 1/1 400 parts by weight Coating liquid for adhesive layer Ethylene-vinyl acetate resin heat seal (AD-37P295, manufactured by Toyo Morton Co., Ltd.) 100 parts by weight Pure water 300 layers Part

Example 2 Example 2 was performed in the same manner as in Example 1 except that the release layer had the following composition. Coating liquid for release layer polyether sulfone (5003P, manufactured by ICI) Glass transition point 125 ° C, 100 parts by weight Polycarbonate (Mitsubishi Gas Chemical Co., Ltd., Iupilon S-3000R) Glass transition point 55 ° C, 500 parts by weight methyl ethyl ketone / Methylene chloride = 1/1 400 parts by weight

Example 3 Example 3 was performed in the same manner as in Example 1 except that the release layer had the following composition. Coating liquid for release layer Polyurethane varnish Glass transition point 135 ° C 100 parts by weight (Chrisbon 8566 (LV) manufactured by Dainippon Ink and Chemicals, Inc.) Acrylic resin (BR-88 manufactured by Mitsubishi Rayon Co., Ltd.) Glass transition Point 105 ° C 50 parts by weight DMF 400 parts by weight

Comparative Example 1 In Example 1, the following coating liquid for a release layer was used. Coating liquid for release layer polyvinyl acetal (Eslek KS-1 manufactured by Sekisui Chemical Co., Ltd.) Glass transition point 105 ° C 100 parts by weight Methyl ethyl ketone / toluene = 1/1 300 parts by weight

Comparative Example 2 In Example 1, the following coating liquid for a release layer was used. Coating liquid for release layer Polyamide resin (Macromelt 6902, Henkel Hakusui Co., Ltd.) Glass transition point 40 ° C. 50 parts by weight Methyl ethyl ketone / toluene = 1/1 400 parts by weight

(Comparative Example 3) Coating solution for release layer Polyurethane varnish Glass transition point 135 ° C 100 parts by weight (Chrisbon 8566 (LV) manufactured by Dainippon Ink and Chemicals, Inc.) 100 parts by weight of DMF

For thermal transfer recording of the above-mentioned present invention and comparative examples
Of the dye receiving layer transfer sheet is overlaid on a postcard made by the government as a transfer object, and a printer manufactured by Mitsubishi Electric Corporation, CP-11
Was heated from the back surface of the dye-receiving layer transfer sheet with a thermal head, and the dye-receiving layer was transferred onto the transfer object via an adhesive layer. Table 1 shows the evaluation results of the heat fusion and tail fin at that time. The evaluation criteria are as follows. Heat fusion ○ ・ ・ ・ No heat fusion △ ・ ・ ・ Sticking occurs due to poor peeling × ・ ・ ・ Film does not peel due to heat fusion Tail fin ○ ・ ・ ・ Tail fin within 1mm occurs △ ・..Tail fins of 1 mm to 3 mm occur ×… Tail fins of 3 mm or more occur

[0034]

[Table 1]

[0035]

According to the present invention, in a normal state, the dye receiving layer and the release layer have appropriate adhesion,
There is no tail fin in the dye receiving layer due to insufficient adhesion.
Further, when transferring the dye receiving layer from the dye receiving layer transfer sheet for thermal transfer recording , since the dye receiving layer and the release layer do not adhere too much, it is possible to prevent the occurrence of jamming due to insufficient releasability. The dye receiving layer can be transferred only to the desired area. Further, since the amount of the residual solvent in the release layer is small, stable transferability of the dye receiving layer can be always obtained.

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41M 5/38-5/40

Claims (4)

(57) [Claims] 1. A thermal transfer method comprising forming a release layer on one side of a substrate and forming a releasable dye-receiving layer on the release layer.
In the dye receiving layer transfer sheet for recording , the release layer,
A dye-receiving layer transfer sheet comprising a resin having a glass transition point of not less than 120 ° C and not more than 160 ° C, and a resin having a glass transition point of not less than 50 ° C and less than 120 ° C. 2. A glass transition point of 50 ° C. with respect to 100 parts by weight of a resin having a glass transition point of 120 ° C. or more and 160 ° C. or less.
The dye-receiving layer transfer sheet according to claim 1, further comprising 10 to 100 parts by weight of a resin having a temperature of less than 120C. 3. The dye-receiving layer transfer sheet according to claim 1, wherein a urethane resin is used as the resin having a glass transition point of not less than 120 ° C. and not more than 160 ° C. 4. A long film is used as the substrate, and a dye layer containing a sublimable dye and / or a protective layer is provided on the side of the long film on which the dye receiving layer is formed. 2. The dye-receiving layer transfer sheet according to claim 1, wherein the sheet is formed in a face-sequential manner with the receiving layer.