JPH10204352A - Method for producing ink composition and thermal transfer sheet and thermal transfer sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sublimation type heat transfer sheet having a dye layer formed on a base sheet, a primer layer provided between the base sheet and the dye layer, or on the other side of the base sheet. In the ink composition of the primer layer provided between the back layer and the base sheet to be formed, high solubility even in a high molecular weight resin as a binder, without using a harmful solvent having flammability, Provided are a thermal transfer sheet having excellent adhesiveness as a primer layer, a method for producing the same, and an ink composition for a primer layer. SOLUTION: In a sublimation type thermal transfer sheet having a dye layer formed on a base sheet, an ink composition for forming a primer layer provided between the base sheet and the dye layer is provided.
It is characterized by comprising a binder resin and a solvent, and using a carbonate compound represented by the following formula I as the solvent. Embedded image

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sublimation type heat transfer sheet in which a primer layer and a dye layer are sequentially provided on a base sheet, or a primer layer and a back layer are sequentially provided on a base sheet. The present invention relates to a production method and an ink composition for forming a primer layer of the thermal transfer sheet.

[0002]

2. Description of the Related Art Conventionally, as a thermal transfer sheet, there has been known a sublimation type thermal transfer sheet in which a dye layer comprising a sublimable dye and a binder resin is provided on a support such as a polyester film. In the meantime, a primer layer can be formed to improve their adhesiveness. The primer layer is generally a coating liquid comprising a high molecular weight polyester resin having a large number of polar functional groups and a solvent such as dioxane that dissolves the resin, that is, a high adhesiveness formed from the ink composition. is there.

[0003]

The ink composition for forming the primer layer having the composition described above uses dioxane as a solvent, but the dioxane has flammability and is harmful. There's a problem. Therefore, public opinion toward the elimination of the use of dioxane as one of the environmental problems is increasing. Further, a polyester resin or an acrylic resin which is optimal as a primer layer has a high molecular weight and does not dissolve in a normal solvent such as methyl ethyl ketone or toluene. Therefore, a solvent having high solubility in place of dioxane has been required. However, a dioxane alternative has not yet been found.

The present invention solves the above-mentioned problems, and in a sublimation-type thermal transfer sheet having a dye layer formed on a substrate sheet, a primer layer provided between the substrate sheet and the dye layer, or In the ink composition of the primer layer provided between the back layer formed on the other side and the base sheet, a harmful solvent having high solubility in a high molecular weight resin as a binder and having flammability, etc. An object of the present invention is to provide a thermal transfer sheet having excellent adhesiveness as a primer layer, a method for producing the same, and an ink composition for the primer layer, without using the same.

[0005]

Means for Solving the Problems To achieve the above object, the present invention relates to a sublimation type heat transfer sheet having a dye layer formed on a substrate sheet, a primer provided between the substrate sheet and the dye layer. In the ink composition forming a layer,
It is characterized by comprising a binder resin and a solvent, and using a carbonate compound represented by the following formula I as the solvent.

Wherein, in Formula I, a and b each represent an integer of 1 to 6, x and y are each 0 or 1, and at least one is 1, and R ₁ and R ₂ each have a carbon number of 1 to 30,
And a group selected from linear or branched alkyl, cycloalkyl, alkenyl, alkylphenyl, benzyl or alkylbenzyl groups in which the total number of carbon atoms of R ₁ and R ₂ is 50 or less, and arbitrary hydrogen is fluorine And R ₁ and R ₂ may be the same. )

Further, in a sublimation type thermal transfer sheet having a dye layer formed on a base sheet, an ink for forming a primer layer provided between the back layer formed on the other side of the base sheet and the base sheet. The composition is characterized by comprising a binder resin and a solvent, and using a carbonate compound represented by the following formula I as the solvent.

Wherein, in Formula I, a and b each represent an integer of 1 to 6, x and y are each 0 or 1, and at least one is 1, and R ₁ and R ₂ each have a carbon number of 1 to 30,
And a group selected from linear or branched alkyl, cycloalkyl, alkenyl, alkylphenyl, benzyl or alkylbenzyl groups in which the total number of carbon atoms of R ₁ and R ₂ is 50 or less, and arbitrary hydrogen is fluorine And R ₁ and R ₂ may be the same. In addition, it is preferable that the above-mentioned carbonate compound is dimethyl carbonate. Further, the proportion of the carbonate compound represented by the above formula I in the solvent of the ink composition is preferably 50% by weight to 100% by weight.

According to the present invention, there is provided a method for producing a sublimation type thermal transfer sheet in which a primer layer and a dye layer are sequentially provided on a base sheet, wherein a carbonic acid represented by the above formula I is used as a solvent in the ink composition of the primer layer. Using an ester compound, the ink composition is coated on a base sheet, dried,
It is characterized in that a dye layer coating solution is applied on the primer layer and dried. Also, a primer layer on the base sheet,
In the method for producing a sublimation type thermal transfer sheet provided with a back layer sequentially, the ink composition of the primer layer is used as a solvent with the carbonic acid ester compound represented by the above formula I to form a base sheet. It is characterized in that it is coated on top and dried, and a back layer coating solution is coated on the primer layer and dried. The present invention provides a sublimation type thermal transfer sheet in which a primer layer and a dye layer are sequentially provided on a base sheet, wherein the solvent of the ink composition of the primer layer is a carbonate compound represented by the above formula I. Features. Also,
In a sublimation-type thermal transfer sheet in which a primer layer and a back layer are sequentially provided on a base sheet, the solvent of the ink composition of the primer layer is a carbonate compound represented by the above formula I.

The function of the present invention is to provide a sublimation type heat transfer sheet in which a primer layer and a dye layer are sequentially provided on a base sheet, or a primer layer and a back layer are sequentially provided on a base sheet. The binder resin of the primer layer is a high molecular weight resin having a large number of polar functional groups, and the resin does not dissolve in a general-purpose solvent, but in the ink composition of the primer layer, comprises a binder resin and a solvent, By using the carbonate compound represented by the formula I as the solvent, the solubility in the high molecular weight resin is very high. Further, it is possible to provide an ink composition having excellent adhesiveness as a primer layer without using a harmful solvent having flammability or the like.

[0009]

Next, embodiments of the present invention will be described. (Ink Composition, Primer Layer) The ink composition of the present invention is characterized by using a carbonate compound represented by the following formula I as a solvent.

Embedded image

(In the formula I, a and b each represent an integer of 1 to 6, x and y each represent 0 or 1, R ₁ and R ₂
Is selected from linear or branched alkyl, cycloalkyl, alkenyl, alkylphenyl, benzyl or alkylbenzyl groups each having from 1 to 30 carbon atoms and the total number of carbon atoms of R ₁ and R ₂ is 50 or less. And any hydrogen may be substituted by fluorine; R ₁ and R
₂ may be the same. )

The carbonate compound represented by the general formula I according to the present invention is represented by the formula I-1 consisting of only a simple carbonic diester structure (x and y are both 0) as shown below. And a compound represented by the formula I-2 (where at least one of x or y is 1) having an oxyalkyl group added thereto.

Embedded image

Embedded image

For the compound of the formula I-1, R ₁
Or R ₂ has 1 to 30 carbon atoms and R ₁ and R ₂
Represents a group selected from linear or branched alkyl, cycloalkyl, alkenyl, alkylphenyl, benzyl or alkylbenzyl having a total of 50 or less carbon atoms, and R ₁ and R ₂ may be the same. The preferable total number of carbon atoms of R ₁ and R ₂ is from ₂ to 36, and particularly preferably R 2
Each of ₁ or R ₂ has 1 to 10 carbon atoms. Incidentally, the most preferred group is an alkyl group. When the carbon number of R ₁ or R ₂ exceeds 30, or when the total number of carbon atoms of R ₁ and R ₂ exceeds 50, the solubility is poor and the boiling point is high.
It is difficult to recover and reuse the used solution by distillation, which is not suitable.

For example, when R ₁ or R ₂ is an alkyl group, the smaller the carbon number, the more water-soluble and the greater the solvent effect, but the lower the flash point. However, as the number of carbon atoms gradually increases, the viscosity increases, the boiling point increases, and oil solubility becomes available instead of water solubility. Note that R ₁ and R ₂
Are more asymmetric, the greater the surfactant effect. Also, R ₁
And any hydrogen of R ₂ may be replaced by fluorine, and it is preferable that half or more of the hydrogens are replaced by fluorine. Having a fluorine atom enhances the dissolving power, raises the flash point, and improves the handleability and safety. The compound, which is a solvent according to the present invention, has a fluorine atom but does not have a chlorine atom and has no volatility, so there is no fear of destroying the ozone layer.

In the formula I-1, depending on the purpose and application, R
_{If 1} and R ₂ are appropriately selected, a desired solvent can be obtained. For example, when the carbon number of the formula I-1 is small, the dissolving effect on rosin and liquid crystal is excellent, and when the carbon number is large, the dissolving effect on fats and oils is excellent. That is, for example, diethyl carbonate and dimethyl carbonate are:
Wax, rosin, liquid crystal, has a better dissolving effect on resin, diisopropyl carbonate, dinormal butyl carbonate, diisobutyl carbonate shows excellent solubility in both rosin, liquid crystal, and oils and fats, furthermore the carbon number When it is larger, the dissolving action on fats and oils is better. Further, R ₁ and R ₂ are asymmetric, for example, methyl heptyl carbonate, methyl octyl carbonate, methyl dodecyl carbonate is
Surface activity is very large.

Next, as shown by the formula I-2, the carbonate compound having an alkyl ether with R ₁ or R ₂ obtained by further adding an oxyalkyl group to the above compound has retained its properties. As it is, hydrophilicity and solubility in resin are further improved, and the flash point is further increased. Therefore, it is extremely excellent as a solvent, its application range is expanded, and safety and handling properties are improved. The oxyalkyl group to be added has 1 to 6 carbon atoms. 6 carbon atoms
If the ratio exceeds the above, the production process becomes complicated and difficulties occur, which is not practical. Preferably, the carbon number is 5 or less,
More preferably, it is 2-4. Further, those having ethers on both sides in the chemical structure have a slightly higher surface activity than those having only one side.

As described above, the carbonate compound represented by the general formula I, which is a component of the ink composition of the primer layer of the present invention, is a safe compound having extremely low toxicity.
In addition, since there is no volatility and the flash point can be raised, the worker can work hygienically and safely. For reference, the toxicity data of dimethyl carbonate are shown below. It turns out that toxicity is very slight. Oral rat LD _50: 13.50mL / kg dermal rat LD _50: 2,500mg / kg inhalation rat LC _50: 140mg / 1t · 4 hours

In the present invention, dimethyl carbonate (DMC) is particularly preferred among the above carbonate compounds. This is because DMC has a boiling point of about 80 ° C. and the same boiling point range as general-purpose solvents such as methyl ethyl ketone and toluene, so that current printing machines and printing conditions can be used as they are. As the solvent that is a component of the ink composition of the present invention, one of the above-mentioned carbonate compounds may be used alone, or two or more thereof may be used in combination. By mixing two or more,
For example, when there are a plurality of binders as constituent components of the ink composition, a suitable solvent can be selected for each type of binder to further enhance the solubility of the binder.

The solvent for the ink composition of the present invention may be any of the conventionally used solvents such as methyl ethyl ketone, toluene and methyl isobutyl ketone in addition to the above-mentioned carbonate compound (including a mixture of two or more). General-purpose solvents may be used. These general-purpose solvents can be used in a range of 100 parts by weight or less based on 100 parts by weight of the carbonate compound. If it is used in an amount of 100 parts by weight or more, the solubility of the binder resin decreases, which is not preferable. By mixing and using these general-purpose solvents, the volatility of the ink is increased, and drying after ink application is quickened.
Further, by using solvents having different boiling points, the surface quality of the ink-coated surface can be improved. Further, the cost of the ink can be reduced.

The primer layer of the sublimation-type thermal transfer sheet of the present invention comprises polyester resin, polyacrylate resin, polyvinyl acetate resin, polyurethane resin, styrene acrylate resin, polyacrylamide resin, polyamide as a binder resin. Resin, polyether resin, polystyrene resin, polyethylene resin,
Examples include polypropylene resins, vinyl resins such as polyvinyl chloride resins and polyvinyl alcohol resins, and polyvinyl acetal resins such as polyvinyl acetoacetal and polyvinyl butyral. A thermoplastic, linear, or random polyester copolymer composed of at least three different components as described in JP-B-6-84117, as a binder resin of a primer layer of a sublimation-type thermal transfer sheet used in the present invention, Because of good adhesion, it can be particularly preferably used. The above components are a) at least selected from the group consisting of terephthalic acid, isophthalic acid, azelaic acid, p-phenylenebis-β-acrylic acid, sebacic acid and 3,5-dicarboxy-1-benzenesulfonic acid. One dibasic acid and b) 2,2-dimethyl-1,3-propanediol, 2,2'-oxydiethanol, 1,4-butanediol, ethylene glycol, 1,6-hexanediol, 1,4 At least one aliphatic diol selected from the group consisting of -cyclohexanedimethanol and 1,4-di (β-hydroxyethoxy) -cyclohexane. In addition, the above linear copolyester is a resin that is hardly soluble in ordinary solvents. However, if the above-mentioned carbonate compound is used, it is easily dissolved to obtain an ink composition as a primer layer coating liquid. be able to.

The coating of the primer layer of the sublimation type thermal transfer sheet of the present invention is performed by a general method such as roll coating, bar coating, gravure coating, gravure reverse coating, and the like. And the coating amount is 0.1 to 2.0 g / m
² (in terms of solid content, hereinafter, the coating amount of the present invention is a numerical value in terms of solid content, unless otherwise specified). Thus, the primer layer coating liquid is applied on the base sheet and dried to form a primer layer.

(Base Sheet) The above ink composition is applied onto a base sheet, and any base sheet having a certain degree of heat resistance and strength conventionally known can be used. May be used, for example, 0.5 to 50 μm
m, preferably paper having a thickness of about 3 to 10 μm, various processed papers, polyester film, polystyrene film, polypropylene film, polysulfone film, aramid film, polycarbonate film, polyvinyl alcohol film, cellophane, etc., and particularly preferred are It is a polyester film.

(Dye layer) The dye layer of the present invention is prepared by substituting a primer layer and a dye layer on a base sheet in this order in a method for producing a sublimation type thermal transfer sheet. Using a carbonate compound represented by the above, the ink composition is coated on a base sheet, dried, and coated with a dye layer coating solution on the primer layer,
It can be formed by drying. The dye layer is
In an appropriate solvent, a dye, a binder resin, and an additive such as an organic filler are added, and each component is dissolved or dispersed,
Prepare a dye layer coating solution, and, as described above, on the primer layer of the substrate sheet, for example, gravure printing method,
A dye layer can be formed by coating by a forming means such as a screen printing method or a reverse roll coating method using a gravure plate, followed by drying.

The dye to be used is not particularly limited, and any dyes used in conventionally known thermal transfer sheets can be effectively used. For example, some preferred dyes include red dyes such as MS Red G, Macrol.
ex Red ViaretR, Ceres Red
7B, Samaron Red HBSL, Resol
in Red F3BS, etc., and as a yellow dye, holon brilliant yellow 6GL, PTY
-52, Macrolex Yellow 6G, and the like,
As blue dyes, Kayaset Blue 714, Waxolin Blue AP-FW, Holon Brilliant Blue S
-R, MS Blue 100 and the like.

As the binder resin for supporting the heat transferable dye as described above, any of conventionally known binder resins can be used. Preferred examples thereof include ethylcellulose, hydroxyethylcellulose, ethylhydroxycellulose, hydroxypropylcellulose, and the like. Methyl cellulose, cellulose acetate, cellulose resins such as cellulose acetate butyrate, polyvinyl alcohol, polyvinyl acetate,
Examples include vinyl resins such as polyvinyl butyral, polyvinyl acetal, polyvinyl pyrrolidone, and polyacrylamide, and polyesters. The coating amount of the dye layer is
0.2g / m ² ~3g / m ² is preferable in the dry state.

(Back Layer) In the thermal transfer sheet of the present invention, a back layer can be provided on the back surface of the base sheet in order to prevent adverse effects such as sticking and printing wrinkles due to the heat of the thermal head. As the resin forming the back layer,
Any conventionally known ones may be used, for example, polyvinyl butyral resin, polyvinyl acetoacetal resin, polyester resin, vinyl chloride / vinyl acetate copolymer, polyether resin, polybutadiene resin, styrene / butadiene copolymer, acrylic polyol, polyurethane Acrylate, polyester acrylate, polyether acrylate, epoxy acrylate, urethane or epoxy prepolymer, nitrocellulose resin, cellulose nitrate resin, cellulose acetopropionate resin, cellulose acetate butyrate resin, cellulose acetate hydrodiene phthalate resin, cellulose acetate Resins, aromatic polyamide resins, polyimide resins, polycarbonate resins, chlorinated polyolefin resins, and the like.

[0026] Examples of the lubricity-imparting agent to be added or overcoated on the back layer made of these resins include phosphate esters,
Silicone oils, graphite powders, silicone-based graft polymers, fluorine-based graft polymers, acrylic silicone graft polymers, acrylic siloxanes, silicone polymers such as aryl siloxanes, and the like, preferably polyols, for example, polyalcohol polymer compounds and polyalcohols This is a layer composed of an isocyanate compound and a phosphate compound, and it is more preferable to add a filler.

The back layer according to the present invention is represented by Formula I as a solvent in the ink composition of the primer layer in the method for producing a sublimation type thermal transfer sheet in which a primer layer and a back layer are sequentially provided on a base sheet. Using a carbonic acid ester compound, the ink composition is coated on a base sheet, dried,
It can be formed by applying a back layer coating solution on the primer layer and drying. The back layer is prepared by dissolving or dispersing the resin, the slipperiness imparting agent, and the filler described above with a suitable solvent to prepare a back layer coating liquid, and forming the base layer as described above. On the primer layer of the sheet,
For example, the back layer can be formed by applying a coating method such as a gravure printing method, a screen printing method, or a reverse roll coating method using a gravure plate, followed by drying. The coating amount of the back layer is 0.1 g / m ² to
3.0 g / m ² is preferred.

As described above, the ink composition of the primer layer of the present invention is used as a primer layer on the front and back of a base sheet of a thermal transfer sheet. It is preferable that the primer layers on both front and back sides are formed from the above-described ink composition, but it may be on either side of the base sheet. In that case, one side may be provided with a primer layer composed of another ink composition, Or may be processed. When the ink composition is used as the primer layer on the dye layer side, the adhesiveness between the base sheet and the dye layer is improved, and the dye layer is abnormal on the image receiving sheet during thermal transfer by a heating means such as a thermal head. Transfer can be prevented. When used as a primer layer on the back side, the adhesion between the substrate sheet and the back layer is improved, and the back layer is not peeled off by friction with the thermal head.

A primer layer using a random linear copolyester derived from one or more aromatic dibasic acids and one or more aliphatic diols, as described in JP-B-6-84117, can be used as a primer layer. In particular, the heat resistance and the scratch resistance are greatly improved as compared with the primer layer using the above resin. The image-receiving sheet used to form an image using the above-mentioned thermal transfer sheet may be any as long as its image-receiving surface has a dye-accepting property for the dye. As a means for applying thermal energy when performing thermal transfer using the thermal transfer sheet and the image receiving sheet, any conventionally known applying means can be used. For example, a thermal transfer printer (for example, a video printer VY-1 manufactured by Hitachi, Ltd.) can be used.
00), a desired image is formed by applying a thermal energy of about 5 to 100 mj / mm ² by controlling the recording time.

[0030]

EXAMPLES The present invention will be specifically described with reference to Examples and Comparative Examples. In the following description, parts or% are based on weight unless otherwise specified. (Example) Lumirror 12F65K as a base sheet
Using Toray Industries, Ltd., ink composition 1 having the following composition was applied on one surface by gravure printing and dried to form a primer layer having a solid content of 0.3 g / m ² . . Ink Composition 1 polyester resin 10 parts (Morton Chemical Co., Mor-Ester 49000) DMC (dimethyl carbonate) 45 parts Methyl ethyl ketone 45 parts

On the primer layer of the above base sheet,
The back layer of the following composition is coated and dried by gravure printing,
The back layer formed a solid content of 0.3 g / m ² . Back layer coating liquid polyvinyl butyral resin 3.6 parts (Esrec BX-1 manufactured by Sekisui Chemical Co., Ltd.) 8.6 parts polyisocyanate (Bernock D750 manufactured by Dainippon Ink Co., Ltd.) Phosphate ester surfactant 2.8 Part (Plysurf A208S manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) Talc (Micro Ace P-3 manufactured by Nippon Talc) 0.7 part Methyl ethyl ketone 32.0 parts Toluene 32.0 parts

Next, the ink composition 1 described above is coated on the other surface of the base sheet by gravure printing.
After drying, the primer layer was formed to have a solid content of 0.3 g / m ^2, and a magenta dye layer coating solution having the following composition was coated on the primer layer by gravure printing, and was then heated at 100 ° C. for 3 minutes. After drying, a magenta dye layer was formed at a solid content of 1.0 g / m ² to prepare a thermal transfer sheet of Example. Magenta dye layer coating liquid Magenta dye (MS RedG) 2.0 parts Polyvinyl acetoacetal 4.0 parts (KS-5 manufactured by Sekisui Chemical Co., Ltd.) Methyl ethyl ketone / toluene = 1/1 93.0 parts

(Comparative Example 1) A primer layer coating solution for a thermal transfer sheet was prepared by using an ink composition 2 having the following composition.
A thermal transfer sheet of Comparative Example 1 was produced in the same manner as in the example. Ink composition 2 polyester resin 4 parts (Morton Chemical Co., Mor-Ester 49000) methyl ethyl ketone / toluene = 1/96 parts

(Comparative Example 2) A primer layer coating solution for a thermal transfer sheet was prepared by using an ink composition 3 having the following composition.
In the same manner as in the example, a thermal transfer sheet of Comparative Example 2 was produced. Ink composition 3 polyester resin (Byron 200, manufactured by Toyobo Co., Ltd.) 20.0 parts Methyl ethyl ketone / toluene = 1/1 80.0 parts

(Evaluation of Ink Composition) Ink Compositions 1 to
Prepare 3 inks, put each ink in a beaker and add 1
After standing for a day, the bottom of the beaker was visually observed for the presence of a precipitate. In the ink composition 1 (Example) and the ink composition 3 (Comparative Example 2), no precipitate was observed. For it,
In the ink composition 2 (Comparative Example 1), a precipitate was confirmed, and the binder resin did not dissolve but only swollen.

(Evaluation of Thermal Transfer Sheet) The thermal transfer sheets of Examples and Comparative Examples were rubbed with a Sumitomo 3M mending tape once with a thumb from the dye layer side and the back layer side with a thumb, and adhered by hand 10 seconds later. A 90 ° peel test was performed to visually check whether a layer had been formed on the mending tape. In the thermal transfer sheet of the example, neither the dye layer nor the back layer was peeled off at all. In the thermal transfer sheet of Comparative Example 1, both the dye layer and the back layer were mottled. In the thermal transfer sheet of Comparative Example 2, both the dye layer and the back layer were completely peeled.

[0037]

As described above, according to the present invention, a sublimation type thermal transfer sheet in which a primer layer and a dye layer are sequentially provided on a base sheet, or a primer layer and a back layer are sequentially provided on a base sheet. In the ink composition of the primer layer, a high molecular weight which is hardly soluble in a general-purpose solvent as a binder, comprising a binder resin and a solvent, and using a carbonate compound represented by the formula I as the solvent. Highly soluble in resins, low risk of flammability, etc., and biodegradable, so primer layer ink composition with excellent safety and handling properties and thermal transfer with excellent adhesion as primer layer You can get a sheet. Further, in a method for producing a sublimation-type thermal transfer sheet in which a primer layer and a dye layer are sequentially provided on a substrate sheet, a carbonate compound represented by Formula I is used as a solvent in the ink composition of the primer layer. By applying and drying the ink composition on a base sheet and applying and drying a dye layer coating solution on the primer layer, or a primer layer and a back layer on the base sheet. In the method for producing a sublimation type thermal transfer sheet, the ink composition of the primer layer is coated on a substrate sheet using a carbonate compound represented by Formula I as a solvent. Coating, drying and coating a back layer coating solution on the primer layer,
By drying, the ink composition of the primer layer has high solubility even in a high molecular weight resin as a binder, does not use harmful solvents having flammability, etc., and has excellent adhesion as a primer layer. A method for manufacturing a thermal transfer sheet can be obtained.

Claims (8)

[Claims] In a sublimation type thermal transfer sheet having a dye layer formed on a base sheet, an ink composition for forming a primer layer provided between the base sheet and the dye layer is provided.
An ink composition comprising a binder resin and a solvent, wherein a carbonate compound represented by the following formula I is used as the solvent. Embedded image (In Formula I, a and b each represent an integer of 1 to 6, x and y are each 0 or 1, and at least one is 1.
R ₁ and R ₂ each have 1 to 30 carbon atoms, and the total number of carbon atoms of R ₁ and R ₂ is 50 or less, linear or branched alkyl, cycloalkyl, alkenyl, alkylphenyl, benzyl or alkyl. Represents a group selected from a benzyl group, any hydrogen may be substituted by fluorine, and R ₁ and R ₂ may be the same. ) 2. An ink for forming a primer layer provided between a back layer formed on the other side of a base sheet and a base sheet in a sublimation-type thermal transfer sheet having a dye layer formed on the base sheet. An ink composition comprising a binder resin and a solvent in the composition, wherein a carbonate compound represented by the following formula I is used as the solvent. Wherein, in Formula I, a and b each represent an integer of 1 to 6, x and y are each 0 or 1, and at least one is 1, and R ₁ and R ₂ each have a carbon number of 1 to 30,
And a group selected from linear or branched alkyl, cycloalkyl, alkenyl, alkylphenyl, benzyl or alkylbenzyl groups in which the total number of carbon atoms of R ₁ and R ₂ is 50 or less, and arbitrary hydrogen is fluorine And R ₁ and R ₂ may be the same. ) 3. The method according to claim 1, wherein the carbonate compound is dimethyl carbonate.
3. The ink composition according to 2. 4. The ratio of the carbonate compound represented by the formula I in the solvent of the ink composition is 50.
The ink composition according to any one of claims 1 to 2, wherein the content is from 100% by weight to 100% by weight. 5. A method for producing a sublimation-type thermal transfer sheet in which a primer layer and a dye layer are sequentially provided on a base sheet,
As a solvent in the ink composition of the primer layer, the above-mentioned formula I
Using a carbonate compound represented by the formula, the ink composition is coated on a base sheet, dried, and coated with a dye layer coating solution on the primer layer, and dried. Of producing a thermal transfer sheet. 6. A method for producing a sublimation-type thermal transfer sheet in which a primer layer and a back layer are sequentially provided on a base sheet,
As a solvent in the ink composition of the primer layer, the above-mentioned formula I
Using a carbonate compound represented by the formula, the ink composition is coated on a base sheet, dried, and coated with a back layer coating solution on the primer layer, and dried. Of producing a thermal transfer sheet. 7. In a sublimation type thermal transfer sheet having a primer layer and a dye layer sequentially provided on a base sheet, the solvent of the ink composition of the primer layer is a carbonate compound represented by the above formula I. A thermal transfer sheet characterized by the following. 8. In a sublimation type thermal transfer sheet in which a primer layer and a back layer are sequentially provided on a substrate sheet, the solvent of the ink composition of the primer layer is a carbonate compound represented by the above formula I. A thermal transfer sheet characterized by the following.