JP2590847B2 - Thermal transfer recording sheet - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a thermal transfer recording sheet. More specifically, the present invention relates to a thermal transfer recording sheet suitable for a sublimation type thermal transfer recording system.

[Conventional technology]

Facsimile, printer,
Various methods such as electrophotography, ink jet, and thermal transfer recording have been studied for color recording of OA terminals such as copiers and color recording of television images.The thermal transfer recording method requires maintenance and operation of equipment. This is advantageous over other methods in terms of simplicity and the small size and low cost of the device.

In this thermal transfer recording method, an image receiving body is superimposed on the ink-coated surface of a thermal transfer recording sheet in which ink containing a coloring material is applied on a base film, and the back surface of the thermal transfer recording sheet is heated with a thermal head. Recording is performed by transferring the color material in the sheet to the image receiving body.

Such a thermal transfer recording system includes a thermal transfer recording system using a thermal transfer recording sheet coated with a hot-melt ink, and a sublimation thermal transfer recording system using a thermal transfer recording sheet coated with an ink containing a sublimable dye. However, the sublimation type thermal transfer recording system can easily control the sublimation transfer amount of the dye by adjusting the energy applied to the thermal head, so that gradation expression is easy and it is particularly advantageous for full color recording.

As the base film of the thermal transfer recording sheet used in the sublimation type thermal transfer recording method, heat resistance, mechanical strength,
A biaxially stretched polyethylene terephthalate film is particularly advantageously used because it has good dimensional stability and is economically advantageous. Polyethylene naphthalate film also has excellent heat resistance, mechanical strength, and dimensional stability, and has excellent performance as a base film.

The color material layer of the thermal transfer recording sheet is formed by applying an ink containing a sublimable dye and a binder resin onto a base film and drying the binder film. Must be heat-resistant so that it does not fuse or fuse with the receiving paper
Further, when preparing an ink, since it is necessary to have good solubility in a solvent, ethyl cellulose, cellulose resins such as acetyl cellulose, polyvinyl butyral resin, polysulfone resin, polyamide resin, polyester resin, polycarbonate resin, etc. Although acetyl cellulose, polysulfone resin and polycarbonate resin are particularly suitable.

However, when a colorant layer is formed on the polyester base film using a polycarbonate resin, a polysulfone resin, acetylcellulose, or the like as a binder resin, the adhesiveness of the colorant layer to the base film is not sufficient, so that the transfer material is used for transfer recording. At the time of sheet production, processing, or transfer recording, the coloring material layer is peeled off, and a thermal transfer recording sheet that can record with high reliability cannot be obtained.

[Problems to be solved by the invention]

An object of the present invention is to provide a sublimation type thermal transfer recording sheet having improved adhesion between a base film and a colorant layer.

[Means for solving the problem]

That is, the present invention relates to a sublimation type thermal transfer recording sheet having a color material layer comprising a sublimable dye and a binder resin on a polyester base film, wherein a polyester-based thermoplastic resin and / or polyurethane is provided between the polyester base film and the color material layer. The present invention provides a thermal transfer recording sheet on which an adhesive layer made of a thermoplastic resin is formed.

The polyester-based thermoplastic resin for forming the adhesive layer used in the present invention can be obtained by condensing a dicarboxylic acid component and a glycol component, and as the dicarboxylic acid component, terephthalic acid, isophthalic acid, 2,5- Aromatic dicarboxylic acids such as naphthalenedicarboxylic acid or ester-forming derivatives of the aromatic dicarboxylic acids, aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, and succinic acid, and ester-forming derivatives of aliphatic dicarboxylic acids Can be given.

Glycol components include ethylene glycol, 1,4
-Aliphatic, alicyclic and aromatic diols such as butanediol, neopentyl glycol, diethylene glycol, triethylene glycol, 1,4-cyclohexanedimethanol, p-xylene diol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc. Can be given. Further, the polyester-based thermoplastic resin used in the present invention can be obtained from an oxymonocarboxylic acid such as oxybenzoic acid or an ester-forming derivative of the oxymonocarboxylic acid in addition to the dicarboxylic acid component and the glycol component. it can.

Further, the polyester-based thermoplastic resin is obtained by copolymerizing a compound having an ester-forming sulfonate group or copolymerizing an ester-forming aliphatic unsaturated compound, and then removing the unsaturated group with sodium sulfite or metabisulfite. By sulfonating with a sulfonating agent such as sodium, it is possible to obtain a water-soluble or water-dispersible polyester-based thermoplastic resin, which can be used in the form of an aqueous liquid for this purpose. .

No particular limitation is imposed on the molecular weight of these polyester-based thermoplastic resins, and those having a glass transition temperature of preferably 5,000 or more and those having a glass transition temperature of 0 to 80 ° C., and those which dissolve or disperse in a coating solution solvent described below are used. Is done.

The polyurethane-based thermoplastic resin for forming the adhesive layer used in the present invention is obtained by reacting an organic diisocyanate component with a hydroxyl group-containing compound.
As organic diisocyanate components, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate,
4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate,
Examples thereof include 1,5-naphthalenediisocyanate, isophorone diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate. Further, as the hydroxyl group-containing compound, various compounds can be used as long as the compound generates a urethane bond with an organic diisocyanate, but preferably,
It is a long-chain diol having a molecular weight of 500 to 5,000 and a chain extender having a molecular weight of less than 500. Examples of these long-chain diols include polyester glycols and ε-caprolactone obtained by a dehydration condensation reaction of low molecular weight glycols such as ethylene glycol and 1,4-butanediol with dibasic acids such as adipic acid and phthalic acid. Lactones such as lactone glycols obtained by ring-opening polymerization of lactones in the presence of the aforementioned low-molecular-weight glycols, etc., polyether glycols such as polyethylene glycols, polypropylene glycols, and polyoxytetramethylene glycols obtained by ring-opening polymerization of ethylene oxide, propylene oxide, and tetrahydrofuran And polycarbonate diols obtained by the reaction of low molecular weight glycols such as 1,6-hexane glycol and diethyl carbonate. In addition, as a chain extender having a molecular weight of less than 500,
Ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexamethylene glycol, neopentyl glycol, cyclohexanedimethanol, 3-methyl-
Low molecular weight glycols such as 1,5-pentanediol and bisphenol A are exemplified. Further, diols having a carboxyl group obtained by adding ethylene oxide, propylene oxide, caprolactone, or the like to dimethylolpropionic acid, dimethylolpropionic acid, or low-molecular-weight polyols such as trimethylolpropane and pentaerythrole can also be used. In some cases, diamines such as ethylenediamine, isophoronediamine, 1,4-butylenediamine and hydrazine may be used as a part of the chain extender.

The molecular weight of these polyurethane-based thermoplastic resins is not particularly limited, but is preferably 5,000 or more.
The glass transition temperature is preferably -30 to 50C.

As a method for forming an adhesive layer using the above-mentioned polyester-based and polyurethane-based thermoplastic resins, a coating solution is prepared by dissolving or dispersing a polyester-based and / or polyurethane-based thermoplastic resin in an appropriate solvent. May be applied on a base film and dried.

Solvents for preparing the coating solution include aromatic solvents such as toluene and xylene, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, ester solvents such as ethyl acetate and butyl acetate, isopropanol, butanol, and methyl cellosolve. Alcohol solvents such as methylene chloride, trichloroethylene and chlorobenzene, ether solvents such as dioxane and tetrahydrofuran, amino solvents such as dimethylformamide and N-methylpyrrolidone, and water.

The amount of the polyester-based or polyurethane-based thermoplastic resin in the coating solution is 1 to 30% by weight, preferably 3 to 20% by weight.
Is appropriate.

If necessary, a dispersing agent, an antistatic agent, an antiblocking agent, an antifoaming agent, a viscosity adjusting agent, and the like can be added to the above coating solution.

As a method of applying the adhesive layer liquid to the polyester base film, for example, a reverse roll coater, a gravure coater, a rod coater, an air doctor coater or the like can be used [Yuji Harazaki “Coating method” (1979) Maki Shoten However, a wire bar or the like can also be used.

As the thickness of the adhesive layer liquid obtained by applying the adhesive layer liquid,
After drying, the thickness is desirably in the range of 0.01 to 2 μm.

Further, in order to form the color material layer of the thermal transfer recording sheet,
An ink is prepared by dissolving or dispersing a sublimable dye and a binder resin having good heat resistance in a suitable solvent, and then applying the ink on the above-mentioned adhesive layer and drying it.

Examples of sublimable dyes include nonionic azo, anthraquinone, azomethine, methine, indoaniline, naphthoquinone, quinophthalone, and nitro dyes.Binder resins include polycarbonate resin and polysulfone. Resin, polyvinyl butyral resin, polyarylate resin, polyamide resin, polyaramid resin, polyimide resin, polyetherimide resin, and cellulose-based resins such as acetylcellulose, methylcellulose, ethylcellulose, etc., among which polycarbonate resin, polysulfone Resins and acetylcellulose are particularly suitable because they have good heat resistance and good solubility in solvents.

As the solvent, aromatic solvents such as toluene and xylene; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ester solvents such as ethyl acetate and butyl acetate; alcohol solvents such as isopropanol, butanol and methyl cellosolve; Halogen solvents such as methylene chloride, trichloroethylene and chlorobenzene, ether solvents such as dioxane and tetrahydrofuran, and amide solvents such as dimethylformamide and N-methylpyrrolidone are used.

In the above-mentioned ink, in addition to the above-mentioned components, if necessary, organic and inorganic non-sublimable fine particles, a dispersant, an antistatic agent, an antiblocking agent, an antifoaming agent, an antioxidant, a viscosity adjusting agent, etc. Can be added.

The ink can be applied by the same method as described for the application of the adhesive layer liquid, and the appropriate coating thickness is 0.1 to 5 μm in dry film thickness.

Also, as a base film of a thermal transfer recording sheet,
Polyethylene terephthalate film has mechanical strength,
Although it is particularly advantageous in terms of dimensional stability, heat resistance, economy, etc., polyethylene naphthalate film is also suitable because it has similar physical properties. The thickness of these base films is suitably from 1 to 30 μm, but preferably from 2 to 15 μm.

When the above-mentioned base film is used, the so-called stinging development may occur in which the base film is fused to the thermal head during transfer recording, and the transfer of the transfer recording sheet becomes difficult. It is desirable to form a heat-resistant lubricating layer on the opposite side.

As a method for forming the heat-resistant active layer, a heat-resistant resin, heat-resistant particles, a surfactant, and the like are dissolved or dispersed in an appropriate solvent to prepare a coating solution, and the coating solution is used as a base film on the opposite side of the colorant layer. It is carried out by coating on top and drying. One form of these methods is disclosed in Japanese Patent Application No. 61-195031.

[Action and effect]

The heat transfer recording sheet of the present invention has good image quality without peeling off the color material layer during the production of the transfer recording sheet, during processing or transfer recording because the adhesion of the color material layer to the base film is good. Records can be obtained with high reliability.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to examples, but the examples do not limit the present invention.

Example 1 (a) Preparation of thermal transfer recording sheet Using the resin solutions shown in Table 1 on one surface of a biaxially stretched polyethylene terephthalate film (thickness: 6 μm), coating was performed with a wire bar to a wet film thickness of about 6 μm. After completion of the drying, drying was performed at 80 ° C. for about 20 seconds to form an adhesive layer.

A solution having the following composition was applied on the adhesive layer of each film, on which the adhesive layer was formed by the above method, with a wet thickness of about 6 μm using a wire bar, followed by drying at 80 ° C. for about 20 seconds. A color material layer was formed.

Colorant layer coating solution composition 5 parts by weight of the following structural formula: 10 parts by weight of polycarbonate resin shown below 85 parts by weight of toluene Reduced viscosity 0.55 Glass transition temperature 192 ° C After applying a liquid of the following composition to the opposite side of the color material layer of each of the above films in a wet film thickness of about 24 μm,
For about 20 seconds to form a heat-resistant lubricating layer to prepare a thermal transfer recording sheet.

Amine catalyst 0.05 parts by weight (trade name: NY-3: manufactured by Nippon Polyurethane Industry Co., Ltd.) Phosphate ester of polyoxyethylene alkyl ether 2.0 parts by weight (trade name: Plysurf A208B; manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight of benzoguanamine resin particles (trade name: Eposter: manufactured by Nippon Shokubai Chemical Co., Ltd.) 84.2 parts by weight of methyl ethyl ketone (b) Adhesion test Adhesive tape (3M) is applied to the color material layer surface of each thermal transfer recording sheet prepared by the above method. Company: Mending Tape 81
After bonding 0), the adhesive tape was peeled off, and the contact property of the color material layer was tested. The color material layer showed good contact without peeling off from the base film.

(C) Transfer Recording Test Each of the thermal transfer recording sheets prepared by the method (a) was subjected to image reception having an image receiving layer made of a polyester resin containing a small amount of amino-modified silicone on the surface of a 150 μm-thick polypropylene synthetic paper. Superimposed on paper, 8 dots / m
Recording was performed under the following conditions using a thin-film type line thermal head having a heating resistor element having a density of m.

Recording line density 8 lines / mm Thermal head applied power 0.4 W / dot Thermal head applied pulse width 1 to 10 ms Each pulse width is varied while changing the applied pulse width from 1 ms to 10 ms every 1 ms. The recording was performed with a width of 5 cm and a length of 1 cm, but the binder resin of the thermal transfer recording sheet did not transfer to the image receiving paper, and a magenta-colored recorded matter having good gradation was obtained.

Comparative Example 1 A thermal transfer recording sheet was produced in the same manner as in Example 1 except that a color material layer was formed directly on the base film without forming an adhesive layer in the production of the thermal transfer recording sheet. As a result of performing the adhesion test and the transfer recording test in the same manner as in the above, the color material layer was easily peeled off in the adhesion test, and the high-energy portion was used in the transfer recording test. Was partially transferred onto the image receiving paper, and the gradation of recording was disturbed.

Example 2 A thermal transfer recording sheet was prepared in the same manner as in Example 1 except that a polysulfone resin (Udel P-1700 manufactured by Union Carbide Co., Ltd.) was used as a binder resin of a coating material for a colorant layer, and chlorobenzene was used as a solvent. The thermal transfer recording sheets were prepared and subjected to adhesiveness and transfer recording tests in the same manner as in Example 1. As a result, the color material layer exhibited good contact properties with each thermal transfer recording sheet and good gradation. A record was obtained.

Comparative Example 2 A thermal transfer recording sheet was produced in the same manner as in Example 2 except that a color material layer was formed directly on the base film without forming an adhesive layer in the production of the thermal transfer recording sheet. As a result of performing an adhesion test and a transfer recording test on each thermal transfer recording sheet in the same manner, the color material layer was easily peeled off in the adhesion test, and the high-energy area was transferred in the transfer recording test. As a result, part of the binder resin of the thermal transfer recording sheet was transferred onto the image receiving paper, and the gradation of the recording was disturbed.

Example 3 Thermal transfer was performed in the same manner as in Example 1 except that an acetylcellulose resin (manufactured by Daicel Chemical Industries, Ltd., L-30) was used as the binder resin of the colorant layer coating solution and methyl ethyl ketone was used as the solvent in the preparation of the thermal transfer recording sheet. A recording sheet was prepared, and the adhesion and the transfer recording test were performed on each thermal transfer recording sheet in the same manner as in Example 1. As a result, the color material layer showed good adhesiveness with each thermal transfer recording sheet, A record of tonality could be obtained.

Comparative Example 3 A thermal transfer recording sheet was prepared in the same manner as in Example 3 except that a color material layer was formed directly on the base film without forming an adhesive layer in the production of the thermal transfer recording sheet. As a result of performing an adhesion test and a transfer recording test on each thermal transfer recording sheet in the same manner, the color material layer was easily peeled off in the adhesion test, and the high-energy area was transferred in the transfer recording test. As a result, part of the binder resin of the thermal transfer recording sheet was transferred onto the image receiving paper, and the gradation of the recording was disturbed.

Example 4 In the production of a thermal transfer recording sheet, a biaxially stretched polyethylene naphthalate film (thickness: 6 μm) was used as a base film in the same manner as in Example 1.
A thermal transfer recording sheet was prepared, and the adhesiveness and the transfer recording test were performed on each thermal transfer recording sheet in the same manner as in Example 1. As a result, the color material layer showed good adhesiveness with each thermal transfer recording sheet, Gradation recording could be obtained.

Comparative Example 4 A thermal transfer recording sheet was produced in the same manner as in Example 4 except that a color material layer was formed directly on the base film without forming an adhesive layer in the production of the thermal transfer recording sheet. As a result of performing an adhesion test and a transfer recording test on each thermal transfer recording sheet in the same manner, the color material layer was easily peeled off in the adhesion test, and the high-energy area was transferred in the transfer recording test. As a result, part of the binder resin of the thermal transfer recording sheet was transferred onto the image receiving paper, and the gradation of the recording was disturbed.

 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Takao Hirota 1000 Kamosida-cho, Midori-ku, Yokohama-shi, Mitsubishi Chemical Industry Co., Ltd. (56) References JP-A-60-240495 (JP, A) JP-A-61 JP-A-61090 (JP, A) JP-A-63-45089 (JP, A) JP-A-60-38199 (JP, A) JP-A-61-41598 (JP, A) JP-A-59-199295 (JP, A) )

Claims (1)

(57) [Claims] 1. A thermal transfer recording sheet having a color material layer composed of a sublimable dye and a binder resin on a polyester base film, wherein the binder resin of the color material layer is selected from the group consisting of a polycarbonate resin, a polysulfone resin, and acetyl cellulose. A thermal transfer recording sheet comprising at least one selected resin, and having an adhesive layer made of at least one of a polyester-based thermoplastic resin or a polyurethane-based thermoplastic resin between the polyester base film and the colorant layer. .