JP2013176902A - Sublimation transfer image receiving sheet and thermal recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sublimation transfer image receiving sheet that can be recorded with small energy by a sublimation transfer recording method using thermal transfer dye, and a thermal recording method that uses the sublimation transfer image receiving sheet and a thermal transfer sheet.SOLUTION: A sublimation transfer image receiving sheet includes a receiving layer formed on a base and a protective layer formed on the receiving layer. The receiving layer includes an organic titanium compound and wax.

Description

  The present invention relates to a sublimation transfer image receiving sheet and a thermal recording method.

  Sublimation transfer in which a dye layer of a thermal transfer sheet in which a thermal transfer dye is applied on a substrate and a dye layer is provided, and a receiving layer is provided on the substrate by applying a thermoplastic resin having a high affinity for the thermal transfer dye. Patent Document 1 discloses a sublimation transfer recording method in which a receiving layer of an image receiving sheet is superposed and heated from the thermal transfer sheet side to transfer and record a thermal transfer dye into the receiving layer.

  Patent Document 2 describes a heat-sensitive recording material in which a transfer layer containing a wax and a pigment is formed on a substrate. The heat-sensitive recording material is a recording material in which the substrate is heated from the surface opposite to the surface on which the transfer layer is formed, and the transfer layer on the back side of the heated portion is transferred to a transfer medium such as paper. Therefore, it is generally called a melt transfer recording method.

  The sublimation transfer recording method is known to be able to record an image with high gradation, but since the energy required for recording is larger than that of the melt transfer recording method, it was desired to enable recording with less energy. . If recording can be performed with less energy, higher speed recording is possible. In recent years, commercial printers occupy a great demand as an application of the sublimation transfer recording method, and further reduction in recording energy is desired.

Japanese Patent Publication No. 5-7194 Japanese Patent Publication No. 5-71396

  In a sublimation transfer recording method using a thermal transfer dye, an object is to obtain a sublimation transfer image receiving sheet capable of recording with less energy. Another object is to obtain a thermal recording method using the sublimation transfer image receiving sheet and the thermal transfer sheet.

  1st invention is equipped with a base | substrate, the receiving layer formed on this base | substrate, and the protective layer formed on this receiving layer, and this receiving layer contains an organic titanium compound and a wax. It is a sublimation transfer image receiving sheet.

  In the second invention, the receiving layer formed between the substrate and the protective layer is formed on the first dye fixing layer formed on the substrate and on the first dye fixing layer. A partition layer, and a second dye fixing layer formed on the partition layer, wherein the first dye fixing layer and the second dye fixing layer include an organic titanium compound and a wax. A sublimation transfer image receiving sheet according to the first invention, which is characterized by the following.

  The third invention is the sublimation according to the second invention, characterized in that the melting temperature of the wax in the first dye fixing layer is lower than the melting temperature of the wax in the second dye fixing layer. It is a transfer image receiving sheet.

  According to a fourth aspect of the present invention, there is provided a dye layer of a thermal transfer sheet comprising a substrate and a dye layer containing a thermal transferable dye and a binder formed on the substrate, and the dye layer of any one of the first to third inventions. Heat-sensitive recording, wherein the substrate is superposed facing the protective layer of the sublimation transfer image-receiving sheet according to the invention, and the substrate is heated by a thermal head from the side opposite to the surface including the dye layer of the thermal transfer sheet. Is the method.

  When printed by heating with a thermal head superimposed on the dye layer of the thermal transfer sheet comprising the dye layer containing the thermal transfer dye and the receiving layer of the sublimation transfer image receiving sheet of the present invention, it is less than the commercially available sublimation transfer image receiving sheet. Equivalent reflection density can be recorded with energy.

It is a schematic cross section of one embodiment of a sublimation transfer image receiving sheet in the present invention. It is a schematic cross section of one embodiment of a sublimation transfer image receiving sheet in the present invention. It is a schematic diagram of a sublimation transfer recording method.

  FIG. 3 is a schematic diagram for explaining the sublimation transfer recording method of the present invention. Provided on a substrate 5 on a protective layer 3 of a sublimation transfer image-receiving sheet 40 comprising a substrate 1, a receiving layer 2 provided on the substrate 1, and a protective layer 3 provided on the receiving layer 2. The obtained dye layer 4 and the dye layer 4 of the thermal transfer sheet 50 including the heat-resistant slip layer 6 provided on the substrate 5 on the surface different from the dye layer are overlapped and sandwiched between the platen roll 21 and the thermal head 22. Now, while moving the sublimation transfer image receiving sheet and the thermal transfer sheet at the same time, by supplying thermal energy based on the image signal from the thermal head, the amount of transfer of the thermal transfer dye to the receiving layer changes depending on the amount of applied thermal energy Thus, an image with gradation can be recorded.

  When the heat transferable dye is introduced into the receiving layer, the material itself forming the receiving layer during recording also has a gentle structure due to thermal motion, and the dye is likely to pass through. Conventional thermal transfer image-receiving sheets are provided with a heat insulating layer so that the amount of heat from the thermal head efficiently heats the resin of the receiving layer and does not wastefully flow toward the substrate. Further, in order to improve the adhesion between the thermal head and the receiving layer, a cushion layer is provided so that heat is efficiently applied to the receiving layer to increase the temperature of the resin of the receiving layer.

  Increasing the temperature of the resin in the receiving layer is to promote activation of the thermal motion of the receiving layer resin, and is not intended to increase the temperature of the receiving layer resin itself. The present invention has arrived at the present invention by paying attention to this point, designing a receiving layer in which thermal motion becomes active with less energy, and introducing a new principle to the dye fixing method.

  The conventional sublimation transfer recording method is also recorded in the same manner as in FIG. 3 except that the conventional sublimation transfer image receiving sheet includes a release layer instead of the protective layer 3. Further, the sublimation transfer image receiving sheet in the conventional sublimation transfer recording method uses a thermoplastic resin having a high affinity for the heat transferable dye as the receiving layer. In the sublimation transfer image receiving sheet of the present invention, the receiving layer containing an organic titanium compound and a wax is used. Is different.

  As shown in FIG. 1, the sublimation transfer image receiving sheet 40 of the present invention has a receiving layer 2 containing an organic titanium compound and wax formed on a substrate 1 and a protective layer 3 formed on the receiving layer 2. is there. The organotitanium compound is considered to react with the functional group contained in the thermal transfer dye to fix the thermal transfer dye in the receiving layer. It is considered that the wax increases the fluidity during image printing and facilitates the transfer of the heat transferable dye from the heat transfer sheet to the receiving layer. The protective layer is considered to prevent fusion between the wax and the thermal transfer sheet.

  FIG. 2 shows a sublimation transfer image receiving sheet 41 according to the second embodiment of the present invention. A first dye fixing layer 11 is formed on the substrate 1, a partition layer 12 is formed on the first dye fixing layer, and a second dye fixing layer 13 is formed on the partition layer 12, The protective layer 3 is formed on the second dye fixing layer 13. The first dye fixing layer 11 and the second dye fixing layer 13 contain an organic titanium compound and a wax. As the receiving layer becomes thicker, the wax tends to flow during printing. Therefore, by providing the partition layer 12 by dividing the receiving layer 2 into two layers, the thickness of each dye fixing layer is reduced to reduce the flow of wax. It is thought to prevent. In order to prevent the wax from flowing during printing, a polymer compound is contained in the receiving layer 2 in FIG. 1, the first dye fixing layer 11 and the second dye fixing layer 13 forming the receiving layer 2 in FIG. It may be added.

  Heat from the thermal head is transmitted from the protective layer 3 to the lower substrate side. It is considered that the temperature increase of the first dye fixing layer 11 is lower than the temperature increase of the second dye fixing layer 13. If the melting temperature of the wax in the first dye fixing layer is lower than the melting temperature of the wax in the second dye fixing layer, the wax of the first dye fixing layer increases the fluidity and protects even at a low temperature. It is considered that the heat transferable dye reaches the first dye fixing layer 11 and is fixed by passing through the layer 3, the second dye fixing layer 13, and the partition wall layer 12.

  The thermal transfer dye in the dye layer formed on the thermal transfer sheet contains a functional group such as a hydroxyl group, a carboxyl group, and an amino group. When the thermal transfer sheet is superposed on the sublimation transfer image receiving sheet having the receiving layer of the present invention and heated and printed from the back side of the thermal transfer sheet, the thermal transfer dye is transferred from the dye layer into the receiving layer, and the functional group of the thermal transfer dye is provided. It is considered that the thermal transfer dye is fixed in the receiving layer by reacting with the organic titanium compound in the receiving layer. This is the thermal recording method of the present invention.

  The substrate is not particularly limited as long as it has a smooth surface and moderate rigidity. The receiving layer formed on the substrate receives the heat transferable dye moving from the heated heat transfer sheet and fixes the heat transferable dye in the receiving layer.

  The gist of the present invention is that the organic titanium compound reacts with a functional group such as a hydroxyl group, a carboxyl group, an epoxy group, or an amino group. Wax is used instead of thermoplastic resin because the organic titanium compound contained in the wax is easier to move even with low printing energy than the organic titanium compound contained in the thermoplastic resin. This is because it is likely to react with the sex dye.

  In order for the heat transferable dye to react with the organotitanium compound, the heat transferable dye must penetrate into the receiving layer. In the present invention, it is considered that the thermal transfer dye can enter when the temperature of the wax increases and the fluidity of the wax increases. The conventional sublimation transfer image receiving sheet uses a thermoplastic resin in the receiving layer, and it is considered that the thermal transfer dye can enter when the temperature of the thermoplastic resin rises and the resin is in intense thermal motion. .

It is believed that much less energy is required to bring the wax into a molten state than the energy required to cause the thermoplastic resin to move violently. Further, it is considered that the heat transferable dye can enter the wax having increased fluidity more easily than the heat transferable dye intrudes into the thermoplastic resin that is in intense thermal motion.
As a result, it is considered that the sublimation transfer image receiving sheet of the present invention can be recorded with less printing energy than the conventional sublimation transfer recording method.

  The preferred amount of organotitanium compound contained in the receiving layer is 0.4 g / square meter to 2.0 g / square meter, and a more preferred amount is 0.8 g / square meter to 1.2 g / square meter.

  The thickness of the receiving layer is preferably 1.5 μm to 6.0 μm, more preferably 2.0 μm to 3.0 μm. The weight ratio of organotitanium compound to wax in the receiving layer is in the range of 2: 1 to 1: 5. More preferably, it is the range of 1: 1 to 1: 2.

  The receiving layer wax may be a mixture of a plurality of types of waxes. By mixing waxes having different melting points, a print density curve (γ curve) with respect to signal input can be changed. In addition, a polymer compound other than wax may be added to the receiving layer. If a polymer compound is present in the wax, the polymer compound is difficult to flow. It can be expected to prevent movement in the receiving layer. The polymer compound may be a thermoplastic resin or a crosslinked resin. In addition, the polymer compound may react with the organic titanium compound. If the thermal transfer dye is fixed to the polymer compound via the organic titanium compound, the stability of the image is considered to be improved. The ratio of the polymer compound to the weight 1 of the wax is preferably 0.5 or less, and more preferably 0.3 or less.

The protective layer prevents the receiving layer from being fused to the thermal transfer sheet. The protective layer needs to have a low affinity for the heat transferable dye and easily pass through the heat transferable dye. The protective layer is required to be as thin as possible, toughness that does not break even when pressed by a thermal head, and heat resistance that does not melt even when heated. As the protective layer, a cellulose-based resin or a crosslinked resin is preferable. Alternatively, a resin obtained by mixing a cellulose resin and a crosslinkable resin may be crosslinked and used.
The thickness of the protective layer is preferably as thin as possible so that the thermal transfer dye can easily pass through.
A thickness in the range of 0.10 μm to 0.30 μm is preferred.
A thickness in the range of 0.15 μm to 0.20 μm is more preferable.

When the receiving layer is thick, it is preferable to divide the receiving layer into a first dye fixing layer and a second dye fixing layer and provide a partition layer between the two dye fixing layers. The partition layer is preferably a resin having low affinity for the heat transferable dye. Further, the partition wall layer needs to be as thin as possible, toughness that does not break even when pressed by a thermal head, and heat resistance that does not melt even when heat is applied.
As the partition layer, a cellulose-based resin or a crosslinked resin is preferable.
The partition layer is preferably as thin as possible so that the thermal transfer dye can easily pass through.
A thickness in the range of 0.05 μm to 0.20 μm is preferred. A thickness in the range of 0.08 μm to 0.12 μm is more preferable.

A preferred amount of the organotitanium compound contained in the first dye fixing layer is 0.2 g / square meter to 1.0 g / square meter, and a more preferred amount is 0.4 g / square meter to 0.8 g / square meter.
The preferred thickness of the first dye fixing layer is 1.0 μm to 3.0 μm, more preferably 1.5 μm to 2.0 μm. A preferred weight ratio of the organotitanium compound to the wax in the receiving layer is in the range of 1 to 0.8 to 1 to 8. More preferably, it is the range of 1: 1 to 1: 5.

A preferred amount of the organotitanium compound contained in the second dye fixing layer is 0.4 g / square meter to 2.0 g / square meter, and a more preferred amount is 0.8 g / square meter to 1.2 g / square meter.
The preferred thickness of the second dye fixing layer is 1.0 μm to 3.0 μm, more preferably 1.5 μm to 2.0 μm. A preferred weight ratio of organotitanium compound to wax in the receiving layer is in the range of 1 to 0.5 to 1 to 3. More preferably, it is the range of 1: 1 to 1: 2.

  The difference between the melting temperature of the wax contained in the first dye fixing layer and the melting temperature of the wax contained in the second dye fixing layer is preferably in the range of 10 ° C to 50 ° C. When the difference in the melt viscosity of the waxes in the two dye fixing layers is too small, the amount of the heat transferable dye that enters the first dye fixing layer is reduced. If the difference between the melting temperatures of the waxes in the two dye fixing layers is too large, the image storage stability may be deteriorated.

The material used for this invention is demonstrated below.
<Substrate>
The material that can be used as the substrate is not particularly limited as long as it can be conveyed by a printer, but generally, pulp paper, coated paper, art paper, cast coat made from natural pulp, synthetic pulp, or a mixture thereof. Paper, ivory, coated ivory, etc., white board paper, high-grade white board paper, etc., or resin-coated paper (RC paper) obtained by extruding a molten resin on the surface of the paper and coating it with resin can be used.

  Alternatively, as a synthetic paper, YUPO (registered trademark) and Super YUPO (registered trademark) manufactured by Yupo Corporation, Peach Coat (registered trademark) manufactured by Nisshinbo Paper Products Co., Ltd., and the like can also be used as a substrate.

  White polyester films in which a white pigment or the like is dispersed in a polyester film are sold by Toray Industries, Inc. and Teijin DuPont Films, Inc., both of which can be used as a substrate. Alternatively, various transparent plastic films and white polyvinyl chloride films can be used as the substrate depending on the application.

<Organic titanium compound>
There are organic titanium compounds that are soluble in organic solvents and organic titanium compounds that are soluble in water-based solvents.
Examples of the organic titanium compound dissolved in the organic solvent include tetra-iso-propoxytitanium, tetra-n-butoxytitanium, tetrakis (2-ethylhexyloxy) titanium, titanium-iso-propoxyoctylene glycolate, di-iso- Propoxy bis (acetylacetonato) titanium, titanium tetraacetylacetate, propanedioxytitanium bis (ethylacetoacetate), tri-n-butoxytitanium monostearate, di-iso-propoxytitanium distearate, titanium stearate, Di-iso-propoxytitanium diisostearate, (2-n-butoxycarbonylbenzoyloxy) tributoxytitanium, and the like can be used.

The following organic titanium compound polymers can also be used.
Polymers of tetra-iso-propoxytitanium

  Tetra-n-butoxytitanium polymer

Examples of organic titanium compounds that are soluble in aqueous solvents include di-n butoxy bis (triethanolaminato) titanium, titanium lactate, polyhydroxytitanium stearate, and titanium diisopropoxybis (triethanolaminate). can give.
An aqueous solvent refers to a solution obtained by adding a hydrophilic solvent such as alcohol or ketone to water.

<Wax>
A wax is an oily substance with a high melting point that refers to an ester of a higher fatty acid and a monohydric or dihydric higher alcohol, or a neutral fat, a higher fatty acid, a hydrocarbon, or the like that exhibits similar properties. And paraffinic waxes, which are waxy hydrocarbons obtained by fractional distillation of crude oil. Furthermore, chemically synthesized synthetic waxes are also included.

  Examples of the wax that can be used in the present invention include waxes such as paraffin wax, microcrystalline wax, polyethylene wax, beeswax, white wax, carnauba wax, montan wax, ceresin wax, and caster wax. Alternatively, stearic acid and its derivatives such as stearic acid, stearamide, and metal stearates, and waxy compounds such as higher fatty acid amides can also be used.

  Synthetic waxes can also be used in the present invention. A synthetic wax can be produced by the reaction of an isocyanate compound and a compound having active hydrogen. A compound having an isocyanate group such as a monoisocyanate compound, a diisocyanate compound, or a triisocyanate compound, a compound having active hydrogen, for example, a compound having an alcohol group, a compound having an amino group, a compound having a thiol group, a compound having a carboxylic acid group A wax synthesized by reaction with can be used. Ester waxes obtained from the reaction of higher fatty acids with higher alcohols can also be used.

Natural wax is not uniform and the melting temperature may vary from lot to lot. In that respect, the synthetic wax is uniform, has no impurities, and the melting temperature can be designed to a predetermined temperature.
As an example, the reaction product of an isocyanate such as monoisocyanate, diisocyanate, triisocyanate and a monohydric alcohol is solid at room temperature, has a clear melting point with a narrow temperature range, and has sufficient strength and various resistances in the solid state. Have

The reaction itself of reacting a compound having an isocyanate group with a compound having these active hydrogens is known, and for example, it reacts as follows.
RNCO + R′NH ₂ → RNHCONHR ′
RNCO + R'OH → RNHCOOR '
RNCO + R'SH → RNCCOSR '
RNCO + R′COOH → RNCCOOR ′ → RNHCOR ′
Moreover, in order to assist these reactions, you may use a catalyst suitably.

  The following compounds can be used as the compound having an isocyanate group that can be used in the above reaction. For example, monoisocyanates such as methyl isocyanate, ethyl isocyanate, n-propyl isocyanate, n-butyl isocyanate, octadecyl isocyanate, polymethylene polyphenyl isocyanate; 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, dianisidine diisocyanate Metaxylylene diisocyanate, 1,5-naphthalene diisocyanate, transvinylene diisocyanate, N, N ′ (4,4′-dimethyl-3,3′-diphenyldiisocyanate) uredion, 2,6-diisocyanate methyl caproate, etc. Diisocyanate; triphenylmethane triisocyanate, tris (4-phenylisocyanate thiophosphate) 4,4'4 "-trimethyl- , 3 ', 3 "- triisocyanate such as triisocyanate 2,4,6 triphenyl cyanurate; it is possible to use various isocyanates such as.

  Or various industrially produced and sold diisocyanates such as ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate, decamethylene diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, m-tolue. Diisocyanates such as diisocyanate, naphthalene-1,5 diisocyanate, di (p-isocyanyl-cyclohexyl) methane diisocyanate, and tri (p-isocyanylphenyl) methane diisocyanate can also be used.

As the compound having active hydrogen that reacts with isocyanate, a compound having an atomic group such as —OH, —NH ₂ , —SH, —COOH, hydrogen peroxide, hydrogen chloride, hydrogen bromide, or the like can be used. For example, alcohols in which —OH is added to an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group; formic acid, acetic acid, butyric acid, valeric acid, caprylic acid, palmitic acid, etc. Carboxylic acids having 1 to 30 carbon atoms; amines having 1 to 30 carbon atoms such as ammonia, ethylamine, propylamine, butylamine, amylamine, and aniline; and ethyl mercaptan, propyl mercaptan, butyl mercaptan, amyl mercaptan, hexyl mercaptan Thiols having 1 to 30 carbon atoms such as heptyl mercaptan, octyl mercaptan, decyl mercaptan are used.

As another example of the synthetic wax other than the above, the general formula CH ₂ ═C (R1) COOR2

[R1 represents H, CH ₃ , C ₂ H ₅ or C ₃ H ₇ , and R 2 represents a long-chain alkyl group having 17 or more carbon atoms]
A homopolymer of a radically polymerizable unsaturated monomer represented by or a copolymer of the above radically polymerizable unsaturated monomers, having a melting point of 50 ° C. or more and less than 100 ° C., and a melting point width of 4 A vinyl polymer having a temperature of 5 ° C. or lower can be used as the synthetic wax.
The vinyl polymer having a melting point of 50 ° C. or higher and lower than 100 ° C. is usually one having a molecular weight of about 1,000 to 100,000 and a melt viscosity of about 10 to 3000 cp.

<Others>
As the polymer compound that can be added to the receiving layer, a polymer compound highly compatible with wax is suitable. When the polymer compound is precipitated in the wax, a portion where the heat transferable dye is difficult to be dyed is formed, and the image quality is deteriorated. If the wax is a synthetic wax having a urethane bond, a polyurethane polymer compound or a polyester polymer compound is suitable as an additive.
An acrylic resin having a low molecular weight is suitable for addition to the synthetic wax of vinyl polymer. Natural wax can be added to the synthetic wax to adjust various performances.
As other compounds added to the receiving layer, an antioxidant, a reducing agent, an ultraviolet absorber, and the like may be added in order to increase the durability of an image made of a thermal transfer dye.

<Heat transfer dye>
Thermal transferable dyes that can be used for sublimation transfer recording have electron-withdrawing groups and electron-donating groups around the dye structure, and the reaction between these functional groups and organotitanium compounds results in the receiving layer. The dye can be fixed.
The organic titanium compound can react with a functional group such as a hydroxyl group, a carboxyl group, an epoxy group, or an amino group to form an —O—Ti—O— bond with the dye and fix the dye. The reactivity with respect to various functional groups of the organic titanium compound is in the order of hydroxyl group> carboxyl group> epoxy group> amino group, and the reactivity to the hydroxyl group is the highest.
When the functional group directly bonded to the chromophore reacts, there is a possibility that the color tone may change. Therefore, a dye having a functional group that is separated from the chromophore is preferable in the thermal recording method of the present invention. Of course, thermal transfer dyes having a functional group directly bonded to the chromophore can also be used.

  As the thermal transfer dye, a dye having a high solvent solubility, a relatively high molar extinction coefficient, and a good hue selected from disperse dyes and oil-soluble dyes is used from the beginning. There are many dyes developed for sublimation transfer recording, and dyes are selected according to the purpose and used in combination.

Examples of disperse dyes and oil-soluble dyes include the following dyes.
C. I. (Color Index) Disperse Yellow 51, 3, 54, 79, 60, 23, 7, 141, 201, 231.
C. I. Disperse Blue 24, 56, 14, 301, 334, 165, 19, 72, 87, 287, 154, 26, 354.
C. I. Disperse thread 135, 146, 59, 1, 73, 60, 167.
C. I. Disperse violet 4, 13, 26, 36, 56, 31.
C. I. Disperse Orange 149
C. I. Solvent Yellow 56, 14, 16, 29.
C. I. Solvent Blue 70, 35, 63, 36, 50, 49, 111, 105, 97, 11.
C. I. Solvent Red 135, 81, 18, 25, 19, 23, 24, 143, 146, 182.
C. I. Solvent violet 13.
C. I. Solvent Black 3.
C. I. Solvent Green 3.

Specific examples of commercially available dyes include, for example, Kayaset Blue 714 (manufactured by Nippon Kayaku Co., Ltd., Solvent Blue 63), Foron Brilliant Blue SR (Sand Corp., Disperse Blue 354). , Waxoline APFW (ICI, Solvent Blue 36), Magenta dye MS-REDG (Mitsui Toatsu Co., DisperThread 60), Macrolex Red Violet R (Bayer, Disperse Violet 26), Yellow dye Foron brilliant yellow S-6GL (manufactured by Sand, Disperse Yellow 231), Macrolex Yellow 6G (manufactured by Bayer, Disperse Yellow 201), and the like.
These dyes are used in ordinary sublimation transfer recording methods, but can also be used in the thermal recording method of the present invention as long as they have a functional group that reacts with an organic titanium compound.

  As thermal transfer dyes developed for use in the sublimation transfer recording method, for example, compound 3, compound 4, and compound 5 represented by the general formula are thermal transfer dyes of cyan, magenta, and yellow, respectively. By introducing a hydroxyl group, a carboxyl group, an epoxy group, an amino group or the like into these structures, a thermal transfer dye used in the thermal recording method of the present invention can be obtained.

<Dye layer binder and dye layer>
In order to apply the dye to the substrate, a binder for the dye layer is required. As the binder for the dye layer, acetal resins such as polyvinyl butyral resin and polyvinyl acetoacetal resin, and cellulose resins such as ethyl cellulose, hydroxyethyl cellulose, nitrocellulose, cellulose acetate butyrate, and cellulose acetate propionate are used.
Cellulosic resins are suitable for the heat-sensitive recording method of the present invention in that the heat transferable dye is easily released and does not have adhesiveness when heated.

The proportion of the dye binder is preferably 0.3 to 2.0 parts by weight with respect to 1 part by weight of the heat transferable dye. More preferably, the dye binder is in a proportion of 0.5 to 1.2 parts by weight with respect to 1 part by weight of the heat transferable dye.
A preferable coating amount of the dye layer is 0.25 g / square meter to 1.5 g / square meter. More preferably, it is 0.35 g / square meter to 1.2 g / square meter.

<Protective layer>
Cellulose-based resins do not have tackiness even when heated and are strong because they are fibrous and can be used as a protective layer for the sublimation transfer image-receiving sheet of the present invention. In addition, since the affinity with the thermal transfer dye is low, it is considered that the thermal transfer dye released from the thermal transfer sheet does not prevent the penetration of the thermal transfer dye to reach the receiving layer. If the protective layer is too thick, it is difficult for the heat transferable dye to permeate, so there is a contrivance to make it as thin as possible without any unpainted holes. For example, if a simultaneous multilayer coating method is used, a thin protective layer can be formed uniformly.

Cross-linked resins can also be used as the protective layer of the present invention. Various cross-linked resins can be used as the protective layer by combining a cross-linkable resin and a cross-linking agent.
A resin obtained by crosslinking a polymer compound having a hydroxyl group with a polyvalent isocyanate or an organic titanium compound can be used. In addition, a resin obtained by crosslinking a melamine resin and a polymer compound having a hydroxyl group can be used.
A polymer compound having a carboxyl group and a polymer compound having a hydroxyl group can also be used by reacting with each other and crosslinking. In addition, a polymer compound having a carboxyl group and a polymer compound having an oxazoline group can react with each other to use a crosslinked resin.
Further, a polymer compound having an active carbonyl group and a polymer compound having an epoxy group can react with each other to use a crosslinked resin.
A crosslinking reaction using a dehydration condensation reaction of siloxane can also be used.
A complex formation reaction between a polymer compound having a ligand and a metal ion can also be used.
If the cross-linked resin is too thick, the thermal transfer dye will be difficult to permeate, so there is a contrivance to make it as thin as possible without any unpainted holes. For example, if a simultaneous multilayer coating method is used, a thin protective layer can be formed uniformly.

<Partition wall layer>
The partition layer provided between the first dye fixing layer and the second dye fixing layer can also use a cellulose-based resin or a crosslinked resin.
Since the cellulose-based resin is fibrous, the strength thereof is strong, and mixing of the first dye fixing layer and the second dye fixing layer can be prevented. In addition, since the affinity with the thermal transfer dye is low, it is considered that the thermal transfer dye released from the thermal transfer sheet does not prevent the penetration of the thermal transfer dye to reach the first dye fixing layer. If the partition wall layer is too thick, the heat transferable dye becomes difficult to permeate. Therefore, there is a contrivance to make it as thin as possible without any unpainted holes. For example, if a simultaneous multilayer coating method is used, a thin barrier rib layer can be formed uniformly.

A crosslinked resin can also be used as the partition layer of the present invention. Various cross-linked resins can be used as the partition layer by combining a cross-linkable resin and a cross-linking agent.
A resin obtained by crosslinking a polymer compound having a hydroxyl group with a polyvalent isocyanate or an organic titanium compound can be used. In addition, a resin obtained by crosslinking a melamine resin and a polymer compound having a hydroxyl group can be used.
A polymer compound having a carboxyl group and a polymer compound having a hydroxyl group can also be used by reacting with each other and crosslinking. In addition, a polymer compound having a carboxyl group and a polymer compound having an oxazoline group can react with each other to use a crosslinked resin.
Further, a polymer compound having an active carbonyl group and a polymer compound having an epoxy group can react with each other to use a crosslinked resin.
A crosslinking reaction using a dehydration condensation reaction of siloxane can also be used.
A complex formation reaction between a polymer compound having a ligand and a metal ion can also be used.
If the cross-linked resin is too thick, the thermal transfer dye will be difficult to permeate, so there is a contrivance to make it as thin as possible without any unpainted holes. For example, if a simultaneous multilayer coating method is used, a thin protective layer can be formed uniformly.

<Other layers>
Other layers may be provided on the sublimation transfer image-receiving sheet of the present invention. For example, a heat insulating layer may be provided between the receiving layer 2 and the substrate 1. The heat insulating layer is a layer that prevents heat supplied from the thermal head from flowing excessively toward the substrate and wasting heat. It can be produced by dispersing hollow particles or the like in the heat insulating layer.
Further, a primer layer may be formed between the substrate 1 and the receiving layer 2 in order to improve the adhesion between the substrate 1 and the receiving layer 2. A thermoplastic resin or the like is suitable as the primer layer.
Further, a slip layer for adjusting the degree of friction may be provided on the surface of the substrate 1 opposite to the surface on which the receiving layer is provided. This slip layer is used to ensure that the frictional force between the transport roll and the thermal transfer image-receiving sheet has an appropriate value during transport in the printer, and to prevent jamming during transport. The frictional force can be adjusted by applying particles such as talc or silica dispersed in a binder.

The sublimation transfer image receiving sheet can be prepared by sequentially applying the ink forming each layer with a wire bar or a film applicator. A film applicator is a device or apparatus that scrapes ink liquid with a blade with a gap between the film and an application surface.
The hot melt ink can be made into a hot melt ink by adding a solution of an organic titanium compound to a wax and stirring while heating to remove the solvent.
The hot melt ink can be applied to a substrate by a roll coating method or the like in a molten state in a heated ink pan.
Alternatively, wax and an organic titanium compound can be dissolved in a solvent to form a receiving layer forming ink, which can be applied to a substrate by gravure coating, gravure reverse coating or the like. Alternatively, the suspension can be used as a suspension, and an organic titanium compound that is soluble in an aqueous solvent can be added to form a suspension ink, which can be applied to the substrate by gravure coating, gravure reverse coating, or the like.

For the protective layer or partition layer, a protective layer forming ink or partition layer forming ink can be prepared and applied to the receiving layer by gravure coating, gravure reverse coating or the like.
The protective layer and the receiving layer can also be applied in multiple layers simultaneously. According to the simultaneous multilayer coating, the first dye fixing layer, the partition wall layer, the second dye fixing layer and the protective layer can be formed by a single coating. The simultaneous multilayer coating method is suitable as a method for forming the protective layer and the partition wall layer thinly and uniformly.

<Thermal transfer sheet>
A 4.5 μm thick polyester film is corona-treated, and the following heat resistant slipping layer forming ink is applied to the corona-treated surface and cured by aging at 60 ° C. for 3 days so that the dry weight becomes 0.5 g / square meter. Thus, a polyester film with a heat-resistant slip layer was obtained.
Ink for forming heat resistant slipping layer:

4.55 parts by weight of polyvinyl butyral resin “SREC (registered trademark) BX-1, manufactured by Sekisui Chemical Co., Ltd.”
Polyisocyanate 21.0 parts by weight “Bernock (registered trademark) D750-45, solid content 45% by mass, manufactured by DIC Corporation”
Phosphate ester surfactant 3.0 parts by weight “Plysurf (registered trademark) A208N, manufactured by Daiichi Pharmaceutical Co., Ltd.”
0.7 parts by weight of talc "Microace (registered trademark) P-3, manufactured by Nippon Talc Industry Co., Ltd."
Methyl ethyl ketone 100 parts by weight Toluene 100 parts by weight

An ink for forming a dye layer having the following composition was obtained. The polyester film with the heat-resistant slipping layer is coated on the opposite surface of the heat-resistant slipping layer so that the dry weight is 1.0 g / square meter, and the thermal transfer sheet A
I gave
Dye layer forming ink:

Dye A 2 parts by weight Dye B 2 parts by weight Ethylcellulose 4.5 parts by weight Toluene 45 parts by weight Methyl ethyl ketone 45 parts by weight

<Sublimation transfer image receiving sheet>
(Substrate)

  An adhesive layer forming ink having the following composition was applied to one surface of a 39 μm-thick microvoided film provided with a fine void layer, and dried to form an adhesive layer. Next, the coated paper (186 g / square meter) and the microvoid film were bonded together so that the adhesive layer overlapped.

Adhesive layer forming ink:

Polyfunctional polyol “Takelac (registered trademark) A-969V” 30.0 parts by weight
(Mitsui Chemicals)
Isocyanate “Takenate (registered trademark) A-5” 10.0 parts by weight
(Mitsui Chemicals)
60.0 parts by weight of ethyl acetate

Subsequently, a primer layer forming ink having the following composition was applied to the surface opposite to the surface provided with the adhesive layer of the microvoid film by wire bar coating so that the dry coating amount was 2.0 g / square meter. The substrate B with a primer layer was formed by drying.

Ink for primer layer formation:
Polyester polyol "Adcoat (registered trademark)" 15.0 parts by weight
(Toyo Morton Co., Ltd.)
Methyl ethyl ketone / toluene (weight ratio 2: 1) 85.0 parts by weight

A wax was synthesized by the following method.
(Synthetic wax 1)
2,6-Toluene diisocyanate and ethyl cellosolve were mixed at a molar ratio of —NCO groups to —OH groups of 1: 1, and dibutyltin laurate was added as a 0.01 wt% catalyst based on the total amount of the above mixture. The mixture was continuously stirred for 5 hours while keeping at 100 ° C. Thereafter, the reaction product was collected by cooling, and when an -NCO group in the vicinity of 2300 Kaiser was checked using an infrared spectrophotometer, no absorption was observed and it was confirmed that no isocyanate group was present. The melting point of the reaction product was 135 to 140 ° C. and showed a sharp melting point.

(Synthetic wax 2)
Hexamethylene diisocyanate and ethyl alcohol were mixed so that -NCO groups and -OH groups were equimolar, and a mixture in which dibutyltin laurate was added as a 0.01 wt% catalyst in the total amount of the above mixture Stir with heating for hours. The obtained product had a melting point of 83 to 86 ° C., and the presence of an isocyanate group was not recognized by measurement with an infrared spectrophotometer.

(Synthetic wax 3)
A mixture in which hexamethylene diisocyanate and n-propyl alcohol were mixed so that -NCO groups and -OH groups were equimolar, and dibutyltin laurate was added as a 0.01 wt% catalyst in the total amount of the mixture, The mixture was stirred at 15 ° C. for 15 hours. The obtained product had a melting point of 96 to 98 ° C., and the presence of isocyanate groups was not observed by infrared spectrophotometry.

(Synthetic wax 4)
The following composition was refluxed for 2 hours to obtain a synthetic wax 4 of vinyl polymer.

Stearyl acrylate 100 parts by weight α, α'-azobisisobutyronitrile 0.2 part by weight Toluene 150 parts by weight

The obtained synthetic wax 4 of vinyl polymer had an average molecular weight of 2000, a melting point of 53 ° C., and a melting point width of 4.0 ° C.

(Synthetic wax 5)
The following composition was refluxed for 2 hours to obtain a synthetic wax 5 of vinyl polymer.

Behenyl acrylate 100 parts by weight α, α'-azobisisobutyronitrile 0.2 part by weight Toluene 100 parts by weight

The obtained synthetic wax 5 of vinyl polymer had an average molecular weight of 3000, a melting point of 60 ° C., and a melting point width of 3.5 ° C.

Example 1
A receiving layer forming ink 1 having the following composition was prepared.
Receptor layer forming ink 1:
20 parts by weight of synthetic wax 1 16 parts by weight of organic titanium compound “Orgatyx (registered trademark) TC-401”
(Matsumoto Fine Chemical Co., Ltd., weight concentration 65%)
Toluene 30 parts by weight Methyl ethyl ketone 30 parts by weight Ethanol 10 parts by weight

A protective layer forming ink 1 having the following composition was obtained.
Protective layer forming ink 1:
Cellulose acetate propionate resin 20 parts by weight
(Manufactured by Eastman Chemical Co., CAP482-0.5)
Toluene 50 parts by weight Methyl ethyl ketone (MEK) 50 parts by weight

On the primer surface of the substrate B with primer, the receiving layer forming ink 1 was applied with a wire bar and dried to form a receiving layer having a thickness of 3.1 μm.
Protective layer forming ink 1 is diluted with the toluene / MEK one-to-one mixed solvent to the above receiving layer, coated with a film applicator so that the film thickness becomes 0.15 μm after drying, and dried to obtain a sublimation transfer image receiving sheet. 1 was obtained.

  The dye surface of the thermal transfer sheet A is superimposed on the sublimation transfer image receiving sheet 1, and a printer for evaluation (resolution 300 dpi, head resistance value 5300Ω, applied voltage: 14.5 V, printing line speed: 2.0 ms / line, pulse duty 85%) When printing was carried out, a reflection density of 2.1 was obtained at the maximum density of the printed matter. This was one third of the amount of energy required to obtain a reflection density of 2.1 with a commercially available sublimation transfer image receiving sheet. Even when the printed matter was stored at 40 ° C. for 3 days, there was no image distortion.

(Example 2)
A receiving layer forming ink 2 having the following composition was heated to 70 ° C. and prepared.
Receptor layer forming ink 2:
20 parts by weight of synthetic wax 2 10 parts by weight of organic titanium compound “Orgatyx (registered trademark) TC-401”
(Matsumoto Fine Chemical Co., Ltd., weight concentration 65%)
Toluene 20 parts by weight Methyl ethyl ketone 20 parts by weight Ethanol 30 parts by weight

A partition wall forming ink 1 having the following composition was obtained.
Hydroxypropyl methylcellulose 5 parts by weight
(Sakai Industry Co., Ltd., PMB-40HS)
85 parts by weight of ion-exchanged water 10 parts by weight of ethanol

On the primer surface of the substrate B with the primer, the receiving layer forming ink 2 was applied with a wire bar and dried to form a first dye fixing layer having a thickness of 2.0 μm.
The partition layer forming ink 1 was applied on the first dye fixing layer with a film applicator so as to have a dry film thickness of 0.15 μm.
A second dye-fixing layer was formed on the partition layer by using a wire bar with the receiving layer forming ink 1 so that the dry film thickness was 2.0 μm.
On the second dye fixing layer, the protective layer forming ink 1 was applied with a film applicator to a dry film thickness of 0.15 μm and dried to obtain a sublimation transfer image receiving sheet 2.

  The dye surface of the thermal transfer sheet A is superimposed on the sublimation transfer image receiving sheet 1, and a printer for evaluation (resolution 300 dpi, head resistance value 5300Ω, applied voltage: 14.5 V, printing line speed: 2.0 ms / line, pulse duty 85%) As a result of printing, a reflection density of 2.2 was obtained at the maximum density of the printed matter. When the cross section of the printed matter was observed with an optical microscope, it was confirmed that the heat transferable dye was put into the first dye fixing layer.

(Example 3)
A receiving layer forming ink 3 having the following composition was heated to 70 ° C. and prepared.
Receptor layer forming ink 3:
Synthetic wax 1 10 parts by weight Synthetic wax 2 10 parts by weight Urethane resin “Crisbon (registered trademark) 4070” 3 parts by weight
(DIC Corporation, solid content 70%)
17 parts by weight of organotitanium compound “Orgatyx (registered trademark) TC-401”
(Matsumoto Fine Chemical Co., Ltd., weight concentration 65%)
40 parts by weight of toluene 40 parts by weight of methyl ethyl ketone

On the primer surface of the substrate B with the primer, the receiving layer forming ink 3 was applied with a wire bar and dried to form a receiving layer having a thickness of 3.5 μm.
Protective layer forming ink 1 is diluted with the toluene / MEK one-to-one mixed solvent to the above receiving layer, coated with a film applicator so that the film thickness becomes 0.15 μm after drying, and dried to obtain a sublimation transfer image receiving sheet. 3 was obtained.
In the same manner as in Example 1, printing was performed with an evaluation printer. The print density and image storability were good.

Example 4
A protective layer forming ink 2 having the following composition was prepared.
Protective layer forming ink 2:
5 parts by weight of polyvinyl alcohol “GOHSENOL (registered trademark) GM-14L”
(Manufactured by Nippon Synthetic Chemical Industry Co., Ltd.)
Hydroxypropyl methylcellulose 15 parts by weight
(Sakai Industry Co., Ltd., PMB-40HS)
10 parts by weight of organotitanium compound “Orgatyx (registered trademark) TC-310”
(Matsumoto Fine Chemical Co., Ltd., weight concentration 44%)
270 parts by weight of ion-exchanged water 15 parts by weight of 2-propanol

On the primer surface of the substrate B with primer, the receiving layer forming ink 1 was applied with a wire bar and dried to form a receiving layer having a thickness of 3.1 μm.
The ink 2 for forming the protective layer was applied to the receiving layer with a film applicator so that the film thickness after drying was 0.15 μm and dried to obtain a sublimation transfer image receiving sheet 4. The organic titanium compound reacted with a hydroxyl group contained in polyvinyl alcohol and hydroxypropyl methylcellulose to form a crosslinked protective layer.
In the same manner as in Example 1, printing was performed with an evaluation printer. The print density and image storability were good.

(Example 5)
A receiving layer forming ink 4 having the following composition was heated to 70 ° C. and prepared.
Receptor layer forming ink 4:
Synthetic wax 3 20 parts by weight Organic titanium compound “Orgatyx (registered trademark) TC-401” 10 parts by weight
(Matsumoto Fine Chemical Co., Ltd., weight concentration 65%)
Toluene 20 parts by weight Methyl ethyl ketone 20 parts by weight Ethanol 30 parts by weight

On the primer surface of the substrate B with the primer, the receiving layer forming ink 3 was applied with a wire bar and dried to form a first dye fixing layer having a thickness of 2.0 μm.
The partition layer forming ink 1 was applied on the first dye fixing layer with a film applicator so as to have a dry film thickness of 0.15 μm.
A second dye-fixing layer was formed on the partition layer by using a wire bar with the receiving layer forming ink 1 so that the dry film thickness was 2.0 μm.
On the second dye fixing layer, the protective layer forming ink 1 was applied with a film applicator to a dry film thickness of 0.15 μm and dried to obtain a sublimation transfer image receiving sheet 5.
In the same manner as in Example 1, printing was performed with an evaluation printer, and good results were obtained.

(Example 6)
A receiving layer forming ink 5 having the following composition was prepared.
Receptor layer forming ink 5:
10 parts by weight of synthetic wax 4 10 parts by weight of ethylene vinyl acetate copolymer “Evaflex (registered trademark) 310”
(Mitsui DuPont Polychemical Co., Ltd., melting point: 66 ° C)
16 parts by weight of organic titanium compound “Orgatyx (registered trademark) TC-401”
(Matsumoto Fine Chemical Co., Ltd., weight concentration 65%)
Toluene 35 parts by weight Methyl ethyl ketone 35 parts by weight Sublimation transfer image-receiving sheet 6 was obtained in the same manner as in Example 1 except that receptor layer-forming ink 5 was used instead of receptor layer-forming ink 1.
In the same manner as in Example 1, printing was performed with an evaluation printer, and it was confirmed that a high recording density was obtained.

(Example 7)
A receiving layer forming ink 6 having the following composition was prepared.
Receptor layer forming ink 6:
10 parts by weight of synthetic wax 5 10 parts by weight of ethylene vinyl acetate copolymer “Evaflex (registered trademark) 310”
(Mitsui DuPont Polychemical Co., Ltd., melting point: 66 ° C)
16 parts by weight of organic titanium compound “Orgatyx (registered trademark) TC-401”
(Matsumoto Fine Chemical Co., Ltd., weight concentration 65%)
Toluene 35 parts by weight Methyl ethyl ketone 35 parts by weight Sublimation transfer image-receiving sheet 6 was obtained in the same manner as Example 1 except that receptor layer forming ink 6 was used instead of receptor layer forming ink 1.
In the same manner as in Example 1, printing was performed with an evaluation printer, and it was confirmed that a high recording density was obtained.

(Example 8)
A partition wall forming ink 2 having the following composition was obtained.
Hydroxypropyl methylcellulose 5 parts by weight
(Sakai Industry Co., Ltd., PMB-40HS)
5 parts by weight of organic titanium compound “Orgachix (registered trademark) TC-310”
(Matsumoto Fine Chemical Co., Ltd., weight concentration 44%)
90 parts by weight of ion exchange water

A sublimation transfer image-receiving sheet 8, which is a cured resin of the partition wall layer, was obtained in the same manner as in Example 2 except that the partition wall layer formation ink 2 was used instead of the partition wall layer formation ink 1 of Example 2.
In the same manner as in Example 1, printing was performed with an evaluation printer, and good results were obtained.

Example 9
The receiving layer forming ink 1 having the following composition was added to an aqueous solution to which an emulsifier warmed to 60 ° C. was added and stirred to prepare an emulsion solution.
Receptor layer forming ink 1:
20 parts by weight of synthetic wax 1 16 parts by weight of organic titanium compound “Orgatyx (registered trademark) TC-401”
(Matsumoto Fine Chemical Co., Ltd., weight concentration 65%)
Toluene 30 parts by weight Methyl ethyl ketone 30 parts by weight Ethanol 10 parts by weight

The aqueous solution of the emulsifier used the following solution.
5 parts by weight of polyvinyl alcohol “GOHSENOL (registered trademark) GM-14L”
(Manufactured by Nippon Synthetic Chemical Industry Co., Ltd.)
Hydroxypropyl methylcellulose 5 parts by weight
(Sakai Industry Co., Ltd., PMB-40HS)
200 parts by weight of ion exchange water

The following crosslinking agent was added to the emulsion solution to obtain a receiving layer forming ink 7.
10 parts by weight of organotitanium compound “Orgatyx (registered trademark) TC-310”
(Matsumoto Fine Chemical Co., Ltd., weight concentration 44%)

Instead of the substrate B with the primer, a substrate having a primer layer coated with a 2% polyvinyl alcohol solution is prepared, and the receiving layer forming ink 7 is coated on the primer surface with a wire bar and dried to a thickness of 3.3 μm. A receptive layer was formed.
Protective layer forming ink 1 is diluted with the toluene / MEK one-to-one mixed solvent to the above receiving layer, coated with a film applicator so that the film thickness becomes 0.15 μm after drying, and dried to obtain a sublimation transfer image receiving sheet. 9 was obtained.
In the same manner as in Example 1, printing was performed with an evaluation printer, and good results were obtained.

1: Substrate (sheet)
2: Receptor layer 3: Protective layer 4: Dye layer 5: Substrate (film)
6: heat-resistant slip layer 11: first dye fixing layer 12: partition wall layer 13: second dye fixing layer 21: platen roll 22: thermal head 40: sublimation transfer image receiving sheet 41: sublimation transfer image receiving sheet 50: thermal transfer sheet

Claims (4)

A substrate;
A receiving layer formed on the substrate;
A protective layer formed on the receiving layer;
A sublimation transfer image receiving sheet, wherein the receiving layer contains an organotitanium compound and a wax. A receiving layer formed between the substrate and the protective layer,
A first dye fixing layer formed on the substrate;
A partition layer formed on the first dye fixing layer;
A second dye fixing layer formed on the partition layer;
2. The sublimation transfer image receiving sheet according to claim 1, wherein the first dye fixing layer and the second dye fixing layer contain an organic titanium compound and a wax.   The sublimation transfer image receiving sheet according to claim 2, wherein the melting temperature of the wax in the first dye fixing layer is lower than the melting temperature of the wax in the second dye fixing layer. A substrate;
A dye layer comprising a thermal transfer dye and a binder formed on a substrate;
A dye layer of a thermal transfer sheet comprising
The sublimation transfer image-receiving sheet according to any one of claims 1 to 3 is superposed facing the protective layer of the sublimation transfer image-receiving sheet,
A thermal recording method comprising printing the substrate by heating the substrate with a thermal head from the side opposite to the surface including the dye layer of the thermal transfer sheet.

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