JP2015016701A - Thermal transfer recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal transfer recording medium which has high transfer sensitivity during high-speed printing, in other words, can reduce a dye used for a dye layer, and prevents abnormal transfer in printing even after stored under high temperature and high humidity.SOLUTION: There is provided a thermal transfer recording medium in which a heat-resistant slippery layer 40 is provided on one surface of a substrate 10 and an undercoat layer 20 and a dye layer 30 are sequentially formed on the other surface of the substrate, where the undercoat layer 20 is composed mainly of at least one of an alkoxide, a hydrolyzed product thereof and tin chloride, and a vinylpyrrolidone-vinylimidazole copolymer, a water-soluble polymer and a water-dispersible polyester.

Description

  The present invention relates to a thermal transfer recording medium used in a thermal transfer type printer, and is provided with a heat-resistant slipping layer on one surface of a substrate, and an undercoat layer and a dye layer on the other surface of the substrate. Are sequentially formed. More specifically, the transfer sensitivity is high during high-speed printing, that is, the amount of dye used in the dye layer can be reduced, and abnormal transfer in printing can be prevented even after storage under high temperature and high humidity. Image quality that occurs at the edges, that is, the hue of the transfer layer is fused to the heat-sensitive transfer recording medium, resulting in partial matting of the surface of the printed material. The present invention relates to a thermal transfer recording medium capable of reducing the phenomenon.

  In general, a thermal transfer recording medium is an ink ribbon called a thermal ribbon, which is used in a thermal transfer type printer, and has a thermal transfer layer on one side of the substrate and heat resistance on the other side of the substrate. A slipping layer (back coat layer) is provided.

  The heat-sensitive transfer layer is an ink layer that is sublimated (sublimation transfer method) or melted (melt transfer method) by heat generated in the thermal head of the printer, and transferred to the transfer target side. .

  Currently, among the thermal transfer systems, the sublimation transfer system can easily form full-color images with various functions of the printer, so digital camera self-prints, cards such as identification cards, amusement output, etc. Widely used. Along with the diversification of such applications, there is a growing demand for smaller size, higher speed, lower cost, and durability for the printed material obtained. In recent years, durability has been given to the printed material on the same side of the base sheet. 2. Description of the Related Art Thermal transfer recording media having a plurality of thermal transfer layers provided so as not to overlap protective layers and the like that have been widely used have become quite popular.

  As the image receiving sheet on the transfer target side, a solvent-based image receiving sheet having a solvent-based dye receiving layer and a water-based image receiving sheet having an aqueous dye-receiving layer are known. The solvent-based image-receiving sheet is superior to the water-based image-receiving sheet in terms of releasability between the dye layer and the dye-receiving layer, but the glossiness is low. Furthermore, solvent-based image-receiving sheets have a strong irritating odor, which causes health damage when sucked into the human body, and tends to be avoided from use due to problems such as environmental impact due to treatment of waste liquids and the like.

  In recent years, along with the diversification and widespread use of applications, there has been a problem that sufficient print density cannot be obtained with conventional thermal transfer recording media as the printing speed of printers increases. In order to increase the transfer sensitivity, attempts have been made to improve the transfer sensitivity in printing by reducing the thickness of the thermal transfer recording medium. However, wrinkles are caused by heat, pressure, etc. during the manufacture of the thermal transfer recording medium or during printing. It occurs and sometimes has a problem that breakage occurs.

  In addition, attempts have been made to increase the printing density and transfer sensitivity in printing by increasing the dye / resin (Dye / Binder) ratio in the dye layer of the thermal transfer recording medium. It will be up. Not only that, part of the dye migrates to the heat-resistant slipping layer of the thermal transfer recording medium during the winding state in the manufacturing process (so-called setback), and when the rewinding, the migrated dye has other colors. When retransferred to the dye layer or the protective layer (so-called back-inversion) and thermally transferring the contaminated layer to the transfer material, a hue different from the designated color or a so-called background stain occurs.

  In addition, attempts have been made to increase the energy at the time of image formation on the printer side, not on the thermal transfer recording medium side, but the power consumption increases. In addition to that, the life of the thermal head of the printer is shortened, and the dye layer and the transfer target are fused, so that so-called abnormal transfer is likely to occur. On the other hand, when a large amount of a release agent is added to the dye layer or the transfer target in order to prevent abnormal transfer, blurring of the image or background staining may occur.

  Furthermore, when an image is formed by combining a heat-sensitive transfer recording medium and an image-receiving sheet having an aqueous dye-receiving layer (hereinafter sometimes referred to as a receiving layer), the water-based receiving layer and the thermal transfer sheet are thermally fused. As a result, so-called “shine” occurs in which the surface of the printed material is partially matted.

  In order to solve such a demand, several methods have been proposed.

  For example, Patent Document 1 proposes a thermal transfer sheet having an adhesive layer containing a polyvinyl pyrrolidone resin and a modified polyvinyl pyrrolidone resin between a base material and a dye layer.

  Further, for example, Patent Document 2 proposes a thermal transfer sheet having an adhesive layer composed of a polyvinyl pyrrolidone resin or polyvinyl alcohol resin thermoplastic resin and colloidal inorganic pigment ultrafine particles between a base material and a dye layer. Has been.

JP-A-2005-231354 JP 2006-150956 A

  However, when the thermal transfer recording medium proposed in Patent Document 1 was printed with a recent high-speed printer using the sublimation transfer method, abnormal transfer was confirmed, including those stored under high temperature and high humidity. Although it was not done, the transfer sensitivity in printing was low, it did not reach a sufficient level, and shine could not be suppressed sufficiently.

  In addition, when the image was printed on the thermal transfer recording medium proposed in Patent Document 2, the transfer sensitivity in the print was high and reached a sufficient level, but it was abnormal when stored at high temperature and high humidity. Transcription was confirmed, and shine was also confirmed.

  As described above, in the conventional technology, there is a thermal transfer recording medium that has high transfer sensitivity in printing, does not generate abnormal transfer even when stored at high temperature and high humidity, and can be used for a high-speed printer that sufficiently improves the phenomenon of shine. The situation is not found.

  Therefore, in view of the above problems, the present invention has high transfer sensitivity at the time of high-speed printing, that is, it can reduce the dye used for the dye layer, and also has abnormalities in printing even after storage under high temperature and high humidity. Transfer can be prevented, and image quality defects occurring in high density areas, i.e., hue variation occurs when the receiving layer of the transfer target is fused to the thermal transfer recording medium, resulting in partial printing surface It is an object of the present invention to provide a heat-sensitive transfer recording medium that can reduce the phenomenon of so-called “shininess” that causes matting.

  The present invention employs the following configuration in order to solve the above problems.

  The heat-sensitive transfer recording medium according to the present invention comprises a substrate made of a synthetic resin film, a heat-resistant slip layer, an undercoat layer, and a dye layer, and the heat-resistant slip layer is provided on one surface of the substrate. An undercoat layer is formed on the other side of the substrate, a dye layer is formed on the undercoat layer, and the undercoat layer is selected from the group consisting of an alkoxide, a hydrolyzate thereof, and tin chloride. The main component is at least one selected from the group consisting of vinylpyrrolidone-vinylimidazole copolymer, water-soluble polymer, and water-dispersible polyester.

  In addition, the thermal transfer recording medium according to the present invention provides an image by thermal transfer on a thermal transfer image-receiving sheet in which a receiving layer formed by an aqueous coating liquid is formed on a substrate through a hollow particle layer formed by an aqueous coating liquid. The heat-sensitive transfer recording medium comprises a base material made of a synthetic resin film, a heat-resistant slipping layer, an undercoat layer, and a dye layer. One side of the base material is heat-resistant. A slipping layer is formed, an undercoat layer is formed on the other side of the substrate, a dye layer is formed on the undercoat layer, and the undercoat layer is formed from an alkoxide, a hydrolyzate thereof, and tin chloride. The main component is at least one selected from the group consisting of: a vinylpyrrolidone-vinylimidazole copolymer, a water-soluble polymer, and a water-dispersible polyester.

  According to the present invention, the undercoat layer contains, as main components, at least one of an alkoxide, a hydrolyzate thereof, and tin chloride, a vinylpyrrolidone-vinylimidazole copolymer, a water-soluble polymer, and a water-dispersible polyester. As a result, the transfer sensitivity during high-speed printing is high, the amount of dye used in the dye layer can be reduced, and abnormal transfer in printing can be prevented even after storage under high temperature and high humidity. It is possible to obtain a sufficiently satisfactory print with little phenomenon.

  In addition, the polyester of the undercoat layer has excellent adhesion to the base material and the dye layer, and the compatibility with the water-soluble polymer is improved by introducing an ester-forming alkali metal sulfonate compound and diethylene glycol, Moreover, the tolerance with respect to organic solvents, such as MEK, toluene, xylene, is acquired.

  In addition, the vinyl pyrrolidone-vinyl imidazole copolymer in the undercoat layer has good adhesion between the base material and the dye layer after storage at high temperature and high humidity, and reduces the shine of the high density part during high-speed printing. The function can be demonstrated.

  In addition, the alkoxide of the undercoat layer and / or its hydrolyzate or tin chloride is an inorganic component having a high reactivity, and itself undergoes a polycondensation reaction to form a chain or three-dimensional structure while being dried from an aqueous solution. In addition to forming a polymer, it is considered that a water-soluble polymer forms a complex at the molecular level. Therefore, the alkoxide in the undercoat layer and / or the hydrolyzate thereof or the polycondensate of tin chloride is considered to bring about an improvement in transfer sensitivity at the time of high-speed printing, which is insufficient with a water-soluble polymer alone. The composite of water-soluble polyester, alkoxide and / or its hydrolyzate or tin chloride and water-soluble polymer, vinylpyrrolidone-vinylimidazole copolymer is inferior to water-soluble polymer alone after storage at high temperature and high humidity. It is thought to bring about improvements in abnormal transcription and shine.

Furthermore, water-soluble polymer is polyvinyl alcohol, water-dispersible polyester is an ester-forming sulfonic acid alkali metal salt compound as dicarboxylic acid component, diethylene glycol is copolymerized as diglycol component, and alkoxide is tetraethoxysilane. Alternatively, triisopropoxyaluminum or a mixture thereof is used, and the coating amount after drying the undercoat layer is within the range of 0.10 g / m ² or more and 0.30 g / m ² or less, so that the transfer sensitivity at the time of high-speed printing. Therefore, it is possible to obtain a print having a higher density and a higher density, and having no abnormal transfer in the print even after being stored at high temperature and high humidity, so that a sufficiently satisfactory print can be obtained.

1 is a side sectional view of a thermal transfer recording medium according to an embodiment of the present invention.

  Hereinafter, a thermal transfer recording medium according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side sectional view of a thermal transfer recording medium according to an embodiment of the present invention.

  As shown in FIG. 1, the thermal transfer recording medium according to one embodiment of the present invention is provided with a heat resistant slipping layer 40 on one surface of a base material 10 and an undercoat layer 20 on the other surface of the base material 10. A thermal transfer recording medium in which the dye layer 30 is sequentially formed.

  More specifically, the thermal transfer recording medium according to one embodiment of the present invention is provided with a heat-resistant slip layer 40 that imparts slidability with a thermal head on one surface of the substrate 10, and the other of the substrate 10. A coating solution containing at least one of an alkoxide, a hydrolyzate thereof, and tin chloride, a vinylpyrrolidone-vinylimidazole copolymer, a water-soluble polymer, and a water-dispersible polyester as main components is applied to the surface, and dried. The undercoat layer 20 and the dye layer 30 formed in this manner are sequentially formed.

  First, the undercoat layer 20 contains, as main components, at least one of an alkoxide, a hydrolyzate thereof, and tin chloride, a vinylpyrrolidone-vinylimidazole copolymer, a water-soluble polymer, and a water-dispersible polyester. .

  Here, the main component is at least one of an alkoxide, a hydrolyzate thereof, and tin chloride, a water-soluble polymer, a vinylpyrrolidone-vinylimidazole copolymer, and a water dispersibility, as long as this effect is not impaired. It represents that other components may be added in addition to the polyester.

  As the water-soluble polymer, the total of at least one of alkoxide, a hydrolyzate thereof, and tin chloride, a vinylpyrrolidone-vinylimidazole copolymer, and a water-dispersible polyester, Although it means that it is contained in an amount exceeding 50% by mass from the whole, it is preferably 80% by mass or more.

  Since the base material 10 is required to have heat resistance and strength not to be softened and deformed by heat pressure in thermal transfer, for example, polyethylene terephthalate, polyethylene naphthalate, polypropylene, cellophane, acetate, polycarbonate, polysulfone, polyimide, polyvinyl alcohol, A synthetic resin film such as aromatic polyamide, aramid, and polystyrene, and paper such as condenser paper and paraffin paper can be used alone or in combination. Among these, a polyethylene terephthalate film is preferable in view of physical properties, workability, cost, and the like. In addition, the thickness is in the range of 2 to 50 μm in consideration of operability and workability, but in consideration of handling properties such as transfer suitability and workability, the thickness is about 2 to 9 μm. preferable.

  Further, in the base material 10, it is possible to perform an adhesion treatment on the surface on which the heat resistant slipping layer 40 and / or the undercoat layer 20 is formed. As the adhesion treatment, known techniques such as corona treatment, flame treatment, ozone treatment, ultraviolet treatment, radiation treatment, surface roughening treatment, plasma treatment, primer treatment, etc. can be applied, and two or more of these treatments can be applied. It can also be used together. In this embodiment, it is effective to improve the adhesiveness between the base material 10 and the undercoat layer 20, and a primer-treated polyethylene terephthalate film is preferable from the viewpoint of cost.

Next, the heat-resistant slipping layer 40 can be handled by a conventionally known layer. For example, a resin serving as a binder, a functional additive that imparts releasability and slipperiness, a filler, a curing agent, a solvent, and the like are blended. And can be formed by coating and drying. The coating amount after drying of the heat resistant slipping layer 40 is suitably about 0.1 to 2.0 g / m ² . Here, the coating amount after drying of the heat resistant slipping layer 40 is:
This refers to the amount of solid content remaining after the coating solution for forming the heat resistant slipping layer is applied and dried, and the coating amount after drying of the undercoat layer 20 and the coating amount after drying of the dye layer 30 described later are similarly applied. The solid content remaining after the coating liquid is applied and dried.

  The above functional additives are not particularly limited, but include natural waxes such as animal waxes and plant waxes, synthetic hydrocarbon waxes, aliphatic alcohols and acid waxes, fatty acid esters and glycerite waxes. Synthetic wax such as wax, synthetic ketone wax, amine and amide wax, chlorinated hydrocarbon wax, alpha-olefin wax, higher fatty acid ester such as butyl stearate and ethyl oleate, sodium stearate, zinc stearate, Higher fatty acid metal salts such as calcium stearate, potassium stearate, magnesium stearate, long chain alkyl phosphate ester, polyoxyalkylene alkyl aryl ether phosphate ester or polyoxyalkylene alkyl ether phosphate ester It may be mentioned a surfactant such as phosphoric acid esters, such as ether or the like.

  The filler is not particularly limited, but talc, silica, magnesium oxide, zinc oxide, calcium carbonate, magnesium carbonate, kaolin, clay, silicone particles, polyethylene resin particles, polypropylene resin particles, polystyrene resin particles. , Polymethyl methacrylate resin particles, polyurethane resin particles, and the like.

  In addition, the curing agent is not particularly limited, and examples thereof include isocyanates such as tolylene diisocyanate, triphenylmethane triisocyanate, tetramethylxylene diisocyanate, and derivatives thereof.

  In addition, the curing agent is not particularly limited, and examples thereof include isocyanates such as tolylene diisocyanate, triphenylmethane triisocyanate, tetramethylxylene diisocyanate, and derivatives thereof.

  Here, as an example of the heat resistant slipping layer 40, the binder resin may be polyvinyl butyral resin, polyvinyl acetoacetal resin, polyester resin, vinyl chloride-vinyl acetate copolymer, polyether resin, polybutadiene resin, acrylic polyol. , Polyurethane acrylate, polyester acrylate, polyether acrylate, epoxy acrylate, nitrocellulose resin, cellulose acetate resin, polyamide resin, polyimide resin, polyamideimide resin, polycarbonate resin and the like.

  Next, the undercoat layer 20 includes, as essential components, at least one of an alkoxide, a hydrolyzate thereof, and tin chloride, a vinylpyrrolidone-vinylimidazole copolymer, a water-soluble polymer, a water-dispersible polyester, As the main component.

  Examples of the water-soluble polymer include polyvinyl alcohol, polyvinyl pyrrolidone, starch, gelatin, methyl cellulose, ethyl cellulose, carboxymethyl cellulose, and sodium alginate. Among these, polyvinyl alcohol and polyvinyl pyrrolidone are preferable, and polyvinyl alcohol is more preferable.

  The polyvinyl alcohol here is not particularly limited, but is generally obtained by saponifying polyvinyl acetate, and so-called partially saponified polyvinyl alcohol in which several tens of percent of acetate groups remain. To so-called completely saponified polyvinyl alcohol in which only a few percent of acetate groups remain.

  Moreover, the said vinyl pyrrolidone-vinyl imidazole copolymer here is a copolymer of the N-vinyl pyrrolidone type monomer and vinyl imidazole which is a vinyl polymerizable monomer. Examples of the copolymer form include, but are not limited to, random copolymerization, block copolymerization, and graft copolymerization. The N-vinylpyrrolidone-based monomer is not particularly limited, but refers to N-vinylpyrrolidone (N-vinyl-2-pyrrolidone, N-vinyl-4-pyrrolidone, etc.) and derivatives thereof. The derivatives include pyrrolidone rings such as N-vinyl-3-methylpyrrolidone, N-vinyl-5-methylpyrrolidone, N-vinyl-3-benzylpyrrolidone, and N-vinyl-3,3,5-trimethylpyrrolidone. The thing which has a substituent can be mentioned.

  An example of the water-dispersible polyester of the undercoat layer 20 will be described. The dicarboxylic acid component as a copolymerization component in the water-dispersible polyester has an ester-forming alkali metal salt compound as an essential component, phthalic acid, Aromatic dicarboxylic acids such as terephthalic acid, dimethyl terephthalate, isophthalic acid, dimethyl isophthalate, 2,5-dimethylterephthalic acid, 2,6-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, orthophthalic acid, succinic acid, adipic acid, azelain Examples thereof include aliphatic dicarboxylic acids such as acid, sebacic acid and dodecanedicarboxylic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid.

  Further, the water-dispersible polyester is produced by a known polycondensation method by subjecting dicarboxylic acid and diglycol to esterification or transesterification followed by polycondensation reaction, but the production method is not limited at all. is not.

  In addition, as a diglycol component, diethylene glycol, a C2-C8 aliphatic, or a C6-C12 alicyclic glycol etc. are mentioned. Specific examples of the aliphatic having 2 to 8 carbon atoms or the alicyclic glycol having 6 to 12 carbon atoms include, for example, ethylene glycol, 1,3-propanediol, 1,2-propylene glycol. , Neopentyl glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, 1,6- Examples include hexanediol, p-xylylene glycol, and triethylene glycol. One or more of these may be used in combination. In addition, it is preferable to contain 20-80 mol% of diethylene glycol in all glycol components. Even if diethylene glycol is outside this range, the solvent resistance to alcohol can be obtained, but the solvent resistance is insufficient with respect to aromatic solvents such as toluene and xylene.

  In addition, the ester-forming sulfonic acid alkali metal salt compound in the undercoat layer 20 is not particularly limited, but sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfoisophthalic acid, and 4-sulfonaphthalene acid. Examples include alkali metal salts (alkali metal salts of sulfonic acid) such as -2,7-dicarboxylic acid and ester-forming derivatives thereof, and sodium salt of 5-sulfoisophthalic acid and ester-forming derivatives thereof are preferably used. It is done.

  Furthermore, it is preferable to contain 6 to 20 mol% of the ester-forming alkali metal sulfonate compound in the total acid component. More preferably, it is 10-18 mol%. When the ester-forming sulfonic acid alkali metal salt compound is less than 6 mol%, the dispersion time of the resin in water becomes long, and the solvent resistance is not sufficient. Conversely, if it exceeds 20 mol%, the water resistance tends to decrease.

  In addition, the dicarboxylic acid component other than the ester-forming sulfonic acid alkali metal salt compound is preferably an aromatic dicarboxylic acid, and the aromatic nucleus of the aromatic dicarboxylic acid has high affinity with a hydrophobic plastic, thereby improving adhesion. There is an advantage that it is excellent in hydrolysis resistance. In particular, terephthalic acid and isophthalic acid are preferable.

Examples of the alkoxide in the undercoat layer 20 include tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ], triisopropoxyaluminum [Al (O—C ₃ H ₇ ) ₃ ] (—C ₃ H ₇ can be represented by the following general formula such as isopropylalkyl group). Among these, tetraethoxysilane or triisopropoxyaluminum is preferable because it is relatively stable even in an aqueous solvent.

General formula: M (OR) n (1)
(In Formula 1, M represents a metal element such as Si, Ti, Al, or Zr, R represents an alkyl group such as CH ₃ or C ₂ H ₅ , and n represents the oxidation number of the metal element)

Note that tin chloride may be stannous chloride (SnCl ₂ ), stannic chloride (SnCl ₃ ), or a mixture thereof, and may be used in the form of an anhydride or a hydrate.

The coating amount of the undercoat layer 20 after drying is not limited in general, but is preferably in the range of 0.10 g / m ² or more and 0.30 g / m ² or less. If it is less than 0.10 g / m ² , the transfer sensitivity at the time of high-speed printing is insufficient due to deterioration during the lamination of the dye layer 30, and there is a concern that the adhesion to the substrate 10 or the dye layer 30 has a problem. On the other hand, if it exceeds 0.30 g / m ² , the sensitivity of the thermal transfer recording medium itself is affected, and there is a concern that the transfer sensitivity at the time of high-speed printing is insufficient.

The dye layer 30 may be a conventionally known one. For example, the dye layer 30 is formed by preparing a coating solution for forming a dye layer by blending a heat transferable dye, a binder, a solvent, and the like, and applying and drying. A value of about 0 g / m ² is appropriate. The dye layer 30 can be formed of a single layer of one color, or a plurality of dye layers 30 containing dyes having different hues can be repeatedly formed on the same surface of the same base material in the surface order.

  The heat transferable dye of the dye layer 30 is not particularly limited as long as it is a dye that melts, diffuses, or sublimates and transfers due to heat. For example, as yellow components, solvent yellow 56, 16, 30, 93, 33, disperse yellow 201, 231, 33, and the like. Examples of the magenta component include C.I. I. Disperse thread 60, C.I. I. Disperse violet 26, C.I. I. Solvent Red 27, or C.I. I. Solvent Red 19 etc. can be mentioned. As the cyan component, C.I. I. Disperse Blue 354, C.I. I. Solvent Blue 63, C.I. I. Solvent Blue 36, or C.I. I. Disperse Blue 24 and the like. As the ink dye, it is common to perform color matching by combining the above dyes.

  Furthermore, any conventionally known resin binder can be used as the binder of the dye layer 30, and it is not particularly limited, but cellulosic systems such as ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxy cellulose, hydroxypropyl cellulose, methyl cellulose, and cellulose acetate. Examples thereof include vinyl resins such as resins, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, polyvinyl pyrrolidone, and polyacrylamide, polyester resins, styrene-acrylonitrile copolymer resins, and phenoxy resins.

  Here, the ratio of the dye and the binder in the dye layer 30 is preferably dye / binder = 10/100 to 300/100. This is because when the ratio of the dye / binder is less than 10/100, the amount of the dye is too small and the color development sensitivity becomes insufficient, and a good thermal transfer image cannot be obtained, and when this ratio exceeds 300/100, This is because the solubility of the dye is extremely lowered, so that when it becomes a thermal transfer recording medium, the storage stability is deteriorated and the dye is likely to be precipitated. In addition, in the dye layer 30 or the dye layer 30 forming coating solution, it is possible to use known additives such as isocyanate compounds, silane coupling agents, dispersants, viscosity modifiers, stabilizers and the like as long as the performance is not impaired. it can. The heat resistant slipping layer 40, the undercoat layer 20, and the dye layer 30 can be formed by applying and drying by a conventionally known application method. An example of the application method is a gravure coating method. , Screen printing, spray coating, and reverse roll coating.

  Next, an image-receiving sheet on the transfer target side, specifically, an aqueous thermal transfer image-receiving sheet is formed on the substrate 10 with an aqueous hollow particle layer containing at least an aqueous binder and hollow particles, an aqueous binder and a release agent. A water-based receptive layer containing as a main component is laminated.

  The substrate used in the aqueous thermal transfer image-receiving sheet is not particularly limited, but various materials, layer configurations and sizes can be appropriately selected and used according to the purpose of use. Examples thereof include various papers such as paper, coated paper, and synthetic paper (polypropylene, polystyrene, or a composite material obtained by bonding them with paper).

(Hollow particle layer)
In the hollow particle layer, it is preferable to form a hollow particle layer containing hollow particles and an adhesive component on the image receiving paper substrate. Thermal transfer printing is performed by heating from a thermal head, and requires good adhesion between the thermal head and the image receiving paper substrate. Since the image receiving paper base material having the hollow particle layer has cushioning properties, the adhesiveness with the thermal head is improved, and a more uniform image can be obtained at the time of printing.

  As a material for forming the walls of the hollow particles, acrylonitrile, vinylidene chloride, a polymer of styrene acrylate, or the like is preferably used. Examples of the method for producing the hollow particles include a method in which a foaming agent such as butane gas is encapsulated in the resin particles and foamed by heating, an emulsion polymerization method, and the like. As a method of heating and foaming, when using pre-foamed hollow particles obtained by pre-foaming hollow particles by preheat treatment, and after forming a layer containing unfoamed particles by coating or the like, by heat treatment such as a drying step A hollow structure may be formed. From the viewpoint of easily controlling the hollow ratio and particle diameter of the hollow particles, it is generally preferable to use the already-expanded particles.

(Receptive layer)
As the dyeable resin used in the aqueous receiving layer, a thermoplastic resin having high affinity for dyes and good dye dyeability can be used.

  Examples of the resin include vinyl chloride resin, urethane resin, polyester resin, polycarbonate resin, polyvinyl acetal resin, polyvinyl butyral resin, polystyrene resin, polyacrylate resin, acrylic resin, cellulose resin, and polyamide resin. , A thermoplastic resin such as a copolymer resin of a vinyl compound monomer and a monomer having a benzotriazole skeleton and / or a benzophenone skeleton, and these thermoplastic resins may be used alone or in combination of two or more. You may use together.

  Of these, acrylic resins, copolymer resins of vinyl compound monomers and monomers having a benzotriazole skeleton and / or a benzophenone skeleton, and urethane resins are preferable because of excellent light resistance of printed images. This is because the urethane-based resin has a crystalline region in the molecule, and thus abnormal transfer hardly occurs.

  The dyeing resin is more preferably a water-soluble or water-dispersed so-called aqueous system from the viewpoint of environmental load.

  In thermal transfer printing, the receiving layer on the image receiving paper substrate and the dye layer of the ink ribbon are superposed and heated with a thermal head, and then the ink ribbon is peeled off from the receiving layer. Release properties from the ribbon are also required. For this reason, it is preferable to add a release agent to the receiving layer for the purpose of preventing fusion with the ink ribbon and improving printing runnability. Examples of the release agent to be added include silicone oil, polysiloxane graft acrylic resin, waxes, and fluorine compounds.

  In addition, it is preferable to add a crosslinking agent to the receiving layer to improve heat resistance.

  Here, as a crosslinking agent, a carbodiimide compound, an isocyanate compound, an oxazoline compound, and an organic titanium chelate compound are preferable. Among these cross-linking agents, carbodiimide-based cross-linking agents are preferable because they are highly effective in improving heat resistance, are less likely to cause running problems such as ribbon fusion during printing, and are stable in aqueous paints. .

  In addition, it is preferable that the addition amount of the said carbodiimide type crosslinking agent makes it 1-30 parts of carbodiimide type crosslinking agents with respect to 100 parts of resin contained in a receiving layer, and 3-25 parts is more preferable. If it is less than 1 part, sufficient crosslinking effect cannot be obtained, and printing running failure may occur. If it exceeds 30 parts, the curing property of the resin may inhibit the density of the printed image.

Further, the coating amount of the receptor layer is preferably from 0.5 to 5 g / m ^2, more preferably 0.5-4 g / m ^2. If it is less than 0.5 g / m ² , the light resistance of the image may be inferior. If it exceeds 5 g / m ² , the dye may diffuse in the receiving layer, and image bleeding may occur.

(Coating method)
Various auxiliary agents such as wetting agents, dispersants, thickeners, antifoaming agents, colorants, antistatic agents, preservatives and the like used in the production of general coated papers are appropriately added to the above coating layers. . Each coating layer uses a known coater such as a bar coater, gravure coater, comma coater, blade coater, air knife coater, gate roll coater, die coater, curtain coater, and slide bead coater, and a predetermined coating solution. Can be formed by coating and drying each layer or two or more layers simultaneously. Drying is performed by a drying furnace or the like attached to the coater. Examples of the drying method generally include hot air drying and heat drying. The drying temperature can be appropriately selected within the range of 70 to 130 ° C., but is not particularly limited as long as the solvent contained in the coating solution evaporates after coating.

  EXAMPLES Hereinafter, although this invention is further demonstrated based on an Example and a comparative example, this invention is not restrict | limited by the following example. In the following, “part” is based on mass unless otherwise specified.

<Preparation of substrate with heat-resistant slip layer>
As a base material, use a polyethylene terephthalate film with 4.5 μm single-sided easy-adhesive treatment, and apply a heat-resistant slipping layer coating solution having the composition shown below to the non-adhesive-adhesive treated surface by gravure coating method. After coating and drying so as to be 1.0 g / m ² , the substrate with the heat-resistant slipping layer 40 was obtained by aging in a 40 ° C. environment for 1 week.

<Heat resistant slipping layer coating solution>
Acrylic polyol resin 12.5 parts Polyoxyalkylene alkyl ether / phosphate ester 2.5 parts Talc 6.0 parts 2,6-tolylene diisocyanate prepolymer 4.0 parts Toluene 50.0 parts Methyl ethyl ketone 20.0 parts Ethyl acetate 5.0 parts

Example 1
In Example 1, the undercoat layer coating solution-1 having the composition shown below is applied to the easy-adhesion treated surface of the base material with the heat-resistant slip layer 40 obtained by the above-described production method by a gravure coating method. The undercoat layer 20 was formed by applying the coating amount after drying to 0.2 g / m ² and drying at 100 ° C. for 2 minutes. Subsequently, a dye layer coating solution having the composition shown below was applied onto the undercoat layer 20 by a gravure coating method so that the coating amount after drying would be 0.7 g / m ^2. The dye layer 30 was formed by drying for minutes, and the thermal transfer recording medium of Example 1 was obtained.

<Undercoat layer coating solution-1>
Tetraethoxysilane 2.8 parts vinylpyrrolidone-vinylimidazole copolymer 2.8 parts polyvinyl alcohol 2.8 parts water-dispersed polyester 2.1 parts 0.1N hydrochloric acid 53.8 parts pure water 31.8 parts isopropyl alcohol 9 copies

<Dye layer coating solution>
C. I. Solvent Blue 63 6.0 parts Polyvinyl acetal resin 4.0 parts Toluene 45.0 parts Methyl ethyl ketone 45.0 parts

(Example 2)
Example 2 was the same as Example 1 except that the undercoat layer 20 was changed to the undercoat layer coating solution-2 of the composition shown below in the thermal transfer recording medium produced in Example 1 described above. Thus, a thermal recording transfer medium of Example 2 was obtained.

<Undercoat layer coating solution-2>
Stannous chloride 2.8 parts vinylpyrrolidone-vinylimidazole copolymer 2.8 parts polyvinyl alcohol 2.8 parts water-dispersed polyester 2.1 parts 0.1 N hydrochloric acid 53.8 parts pure water 31.8 parts isopropyl alcohol 3 .9 parts

Example 3
In Example 3, in the thermal transfer recording medium produced in Example 1 described above, except that the undercoat layer 20 was applied and dried so that the coating amount after drying was 0.05 g / m ^2. In the same manner as in Example 1, a thermal recording transfer medium of Example 3 was obtained.

Example 4
In Example 4, the thermal transfer recording medium produced in Example 1 was used except that the undercoat layer 20 was applied and dried so that the coating amount after drying was 0.35 g / m ^2. In the same manner as in Example 1, the thermal recording transfer medium of Example 4 was obtained.

(Comparative Example 1)
In Comparative Example 1, the same dye layer coating as in Example 1 was applied on the easy adhesion treatment surface without forming the undercoat layer 20 on the easy adhesion treatment surface of the substrate with the heat resistant slipping layer 40. The liquid was applied and dried by a gravure coating method so that the applied amount after drying was 0.7 g / m ² , thereby forming the dye layer 30, and the thermal transfer recording medium of Comparative Example 1 was obtained.

(Comparative Example 2)
In Comparative Example 2, the coating amount of the undercoat layer coating liquid-3 having the composition shown below was applied to the surface of the easy-adhesion-treated surface of the base material with the heat-resistant slip layer 40 by a gravure coating method so that the coating amount after drying was 0.00. The undercoat layer 20 was formed by applying and drying so as to be ² g / m ² . Subsequently, on the undercoat layer, the same dye layer coating solution as in Example 1 was applied and dried by the gravure coating method so that the coating amount after drying was 0.7 g / m ² . The dye layer 30 was formed, and the thermal transfer recording medium of Comparative Example 2 was obtained.

<Undercoat layer coating solution-3>
Polyvinyl alcohol 4.2 parts Water-dispersed polyester 4.2 parts 0.1N hydrochloric acid 53.8 parts Pure water 33.9 parts Isopropyl alcohol 3.9 parts

(Comparative Example 3)
In Comparative Example 3, the coating amount of the undercoat layer coating liquid-4 having the composition shown below was applied to the surface of the easy-adhesion treated surface of the substrate with the heat resistant slipping layer 40 by a gravure coating method to give a coating amount of 0. The undercoat layer 20 was formed by applying and drying so as to be ² g / m ² . Subsequently, on the undercoat layer 20, the same dye layer coating solution as in Example 1 was applied and dried by the gravure coating method so that the coating amount after drying was 0.7 g / m ^2. The dye layer 30 was formed, and the thermal transfer recording medium of Comparative Example 3 was obtained.

<Undercoat layer coating solution-4>
Tetraethoxysilane 4.2 parts Polyvinyl alcohol 4.2 parts 0.1N hydrochloric acid 53.8 parts Pure water 33.9 parts Isopropyl alcohol 3.9 parts

(Comparative Example 4)
In Comparative Example 4, the coating amount of the undercoat layer coating liquid-5 having the composition shown below was applied to the surface of the easy-adhesion-treated surface of the substrate with the heat resistant slipping layer 40 by a gravure coating method to give a coating amount of 0. The undercoat layer 20 was formed by applying and drying so as to be ² g / m ² . Subsequently, on the undercoat layer 20, the same dye layer coating solution as in Example 1 was applied and dried by the gravure coating method so that the coating amount after drying was 0.7 g / m ^2. The dye layer 30 was formed, and the thermal transfer recording medium of Comparative Example 4 was obtained.

<Undercoat layer coating solution-5>
Tetraethoxysilane 4.2 parts Vinylpyrrolidone-vinylimidazole copolymer 4.2 parts 0.1N hydrochloric acid 53.8 parts Pure water 33.9 parts Isopropyl alcohol 3.9 parts

(Comparative Example 5)
In Comparative Example 5, the coating amount of the undercoat layer coating solution-6 having the composition shown below was applied to the surface of the easy-adhesion treated surface of the substrate with the heat-resistant slip layer 40 by a gravure coating method to give a coating amount of 0. The undercoat layer 20 was formed by applying and drying so as to be ² g / m ² . Subsequently, on the undercoat layer 20, the same dye layer 30 coating solution as in Example 1 is applied and dried by the gravure coating method so that the coating amount after drying is 0.7 g / m ^2. Then, the dye layer 30 was formed, and the thermal transfer recording medium of Comparative Example 5 was obtained.

<Undercoat layer coating solution-6>
Tetraethoxysilane 4.2 parts Polyvinyl alcohol 4.2 parts Water-dispersed polyester 2.1 parts 0.1N hydrochloric acid 53.8 parts Pure water 33.9 parts Isopropyl alcohol 3.9 parts

(Comparative Example 6)
In Comparative Example 6, the coating amount of the undercoat layer coating solution 7 having the composition shown below was applied to the surface of the easy-adhesion-treated surface of the base material with the heat-resistant slip layer 40 by a gravure coating method, and the coating amount after drying was 0. The undercoat layer 20 was formed by applying and drying so as to be ² g / m ² . Subsequently, on the undercoat layer 20, the same dye layer coating solution as in Example 1 was applied and dried by the gravure coating method so that the coating amount after drying was 0.7 g / m ^2. The dye layer 30 was formed, and the thermal transfer recording medium of Comparative Example 6 was obtained.

<Undercoat layer coating solution-7>
Tetraethoxysilane 3.5 parts Polyvinyl alcohol 3.5 parts Vinylpyrrolidone-vinylimidazole copolymer 3.5 parts 0.1N hydrochloric acid 53.8 parts Pure water 33.9 parts Isopropyl alcohol 3.9 parts

  Next, an image receiving paper was prepared. The manufacturing method is as follows.

<Preparation of image receiving paper substrate>
Art paper having a thickness of 180 g / m ² was used as the image receiving paper substrate.

<Formation of hollow particle layer>
On the image receiving paper substrate, a hollow particle layer coating solution having the composition shown below is applied and dried by a gravure coating method so that the coating amount after drying is 10 g / m ^2. The image receiving paper with a hollow particle layer was obtained by aging for 1 week.

<Hollow particle layer coating solution>
45 parts of pre-expanded hollow particles made of a copolymer mainly composed of acrylonitrile and methacrylonitrile (average particle size 3.2 μm, volumetric hollowness 85%)
10 parts of polyvinyl alcohol 45 parts of vinyl chloride vinyl acetate copolymer resin dispersion (vinyl chloride / vinyl acetate = 70/30, glass transition temperature (Tg) = 64 ° C.)
200 parts of water

<Formation of receiving layer>
On the heat insulating layer, a receiving layer coating solution having the composition shown below is applied by a gravure coating method so that the coating amount after drying is 4 g / m ² , dried, and then aged in a 40 ° C. environment for one week. Thus, a receiving layer was obtained.

<Receptive layer coating solution>
97 parts of urethane resin (Glass transition temperature (Tg) = -20 ° C)
Associative urethane thickener 1 part Sulfonic acid surfactant 2 parts Water 200 parts

<Evaluation of adhesion of dye layer at room temperature>
Regarding the thermal transfer recording media of Examples 1 to 4 and Comparative Examples 1 to 6, a cellophane tape having a width of 18 mm and a length of 150 mm was applied on the dye layer 30 of the thermal transfer recording medium stored at room temperature, and immediately thereafter. Table 1 shows the results of evaluation by examining the presence or absence of adhesion of the dye layer 30 to the cellophane tape when peeled off.

The evaluation was performed according to the following criteria.
○: Adhesion of the dye layer is not recognized Δ: Adhesion of the dye layer is recognized very slightly ×: Adhesion of the dye layer is observed on the entire surface

<Evaluation of adhesion of dye layer after storage at high temperature and high humidity>
With respect to the thermal transfer recording media of Examples 1 to 4 and Comparative Examples 1 to 6, the dye layer 30 of the thermal transfer recording media stored for 72 hours at 40 ° C. and 90% RH and then further stored for 24 hours at room temperature. A cellophane tape having a width of 18 mm and a length of 150 mm was applied on top of the film, and then evaluated by examining whether or not the dye layer 30 adhered to the cellophane tape when it was peeled off immediately thereafter. The results are shown in Table 1. The evaluation was performed according to the same standard as the above evaluation at normal temperature.

<Print evaluation>
Regarding the thermal transfer recording media of Examples 1 to 4 and Comparative Examples 1 to 6, the thermal transfer recording media stored at room temperature, and after being stored in a 40 ° C. 90% RH environment for 72 hours, further 24 at normal temperature. Table 1 shows the results of evaluating the maximum reflection density, the presence / absence of abnormal transfer, and the shine by performing solid printing with a thermal simulator using a heat-sensitive transfer recording medium and a transfer medium that have been stored for a long time. Note that the maximum reflection density is a value obtained by measuring a printed portion where no shine is confirmed with X-Rite 528.

<Printing conditions>
Printing environment: 23 ° C, 50% RH
Applied voltage: 29V
Line cycle: 0.7msec
Print density: main scanning 300 dpi sub-scanning 300 dpi

<Abnormal transcription evaluation>
Also, abnormal transcription was evaluated according to the following criteria.
○: Abnormal transfer to the transfer object is not observed Δ: Abnormal transfer to the transfer object is very slight ×: Abnormal transfer to the transfer object is observed on the entire surface

<Electricity evaluation>
Moreover, the evaluation of shine was performed according to the following criteria.
○: shine is not recognized △: shine is partially recognized ×: shine is clearly recognized

  As can be seen from the results shown in Table 1, the thermal transfer recording medium provided with the undercoat layer 20 clearly has a higher speed printing than the thermal transfer recording medium of Comparative Example 1 provided with no undercoat layer 20. It was found that the transfer sensitivity at that time was high.

  Moreover, when water-dispersed polyester is not included from Example 1 and Comparative Examples 3, 5, and 6, adhesion of the dye layer 30 during high-temperature and high-humidity storage and abnormal transfer during printing have also occurred. It has been found that there is a problem with the adhesion of the dye layer 30 during storage.

  Further, in Comparative Examples 2, 3, and 5 containing no vinylpyrrolidone-vinylimidazole copolymer, shine was generated.

  Further, Comparative Example 4 which contains vinylpyrrolidone-vinylimidazole copolymer but does not contain water-soluble polymer shows that there is a problem in the maximum reflection density and abnormal transfer, although shine is at a level that is practically no problem. I understood.

  On the other hand, in Examples 1 and 2 mainly comprising at least one of an alkoxide, a hydrolyzate thereof, and tin chloride, a vinylpyrrolidone-vinylimidazole copolymer, polyvinyl alcohol, and a water-dispersible polyester, It has been found that the adhesion of the dye layer 30 during storage and storage at high temperature and high humidity, abnormal transfer in printing, and shine generated at high density portions are not problematic in practice.

In addition, although the thermal transfer recording medium of Example 3 has good transfer sensitivity, the coating amount of the undercoat layer 20 is less than 0.10 g / m ² , so that the adhesiveness after storage at a somewhat high temperature and high humidity is somewhat. Further, it was found that the thermal transfer recording medium of Example 4 had a reduced transfer sensitivity effect because the coating amount of the undercoat layer 20 exceeded 0.30 g / m ² .

  The thermal transfer recording medium obtained according to the present invention is an ink ribbon used in a sublimation transfer type printer, and in addition to the high speed and high functionality of the printer, various images can be easily formed in full color. It is widely used for self-prints, cards such as identification cards, and amusement output.

10: Base material 20: Undercoat layer 30: Dye layer 40: Heat-resistant slip layer

Claims (13)

A thermal transfer recording medium,
A base material made of a synthetic resin film;
A heat resistant slipping layer;
An undercoat layer,
A dye layer,
The heat resistant slipping layer is formed on one surface of the base material,
The undercoat layer is formed on the other surface of the substrate,
A dye layer is formed on the undercoat layer,
The undercoat layer is mainly composed of at least one selected from the group consisting of an alkoxide, a hydrolyzate thereof, and tin chloride, a vinylpyrrolidone-vinylimidazole copolymer, a water-soluble polymer, and a water-dispersible polyester. A thermal transfer recording medium, characterized in that   The thermal transfer recording medium according to claim 1, wherein the base material made of the synthetic resin film has a thickness of 2 to 50 μm.   The substrate made of the synthetic resin film is any one of polyethylene terephthalate, polyethylene naphthalate, polypropylene, cellophane, acetate, polycarbonate, polysulfone, polyimide, polyvinyl alcohol, aromatic polyamide, aramid, and polystyrene. The thermal transfer recording medium according to claim 1. ^{2. The} thermal transfer recording medium according to claim 1, wherein the coating amount of the heat-resistant slipping layer after drying is 0.1 to 2.0 g / m < ² >.   The heat resistant slipping layer binder resin is polyvinyl butyral resin, polyvinyl acetoacetal resin, polyester resin, vinyl chloride-vinyl acetate copolymer, polyether resin, polybutadiene resin, acrylic polyol, polyurethane acrylate, polyester acrylate, polyether acrylate. 2. The thermal transfer recording medium according to claim 1, wherein the thermal transfer recording medium is any one of epoxy acrylate, nitrocellulose resin, cellulose acetate resin, polyamide resin, polyimide resin, polyamideimide resin, and polycarbonate resin.   2. The thermal transfer recording medium according to claim 1, wherein the water-soluble polymer of the undercoat layer is any one of polyvinyl alcohol, polyvinyl pyrrolidone, starch, gelatin, methyl cellulose, ethyl cellulose, carboxymethyl cellulose, and sodium alginate. . The thermal transfer recording medium according to claim 1, wherein the coating amount of the dye layer after drying is 1.0 g / m ² .   The binder resin of the dye layer is ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxy cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, polyvinyl pyrrolidone, polyacrylamide, polyester resin, styrene- 2. The thermal transfer recording medium according to claim 1, wherein the thermal transfer recording medium is one of an acrylonitrile copolymer resin and a phenoxy resin.   2. The thermal transfer recording medium according to claim 1, wherein the blending ratio of the dye and the binder resin in the dye layer is dye / binder = 10/100 to 300/100.   A thermal transfer recording medium for forming an image by thermal transfer on a thermal transfer image-receiving sheet on which a receiving layer formed by an aqueous coating liquid is formed via a hollow particle layer formed by an aqueous coating liquid on a substrate, The thermal transfer recording medium comprises a base material made of a synthetic resin film, a heat resistant slipping layer, an undercoat layer, and a dye layer, and the heat resistant slipping layer is formed on one surface of the base material. The undercoat layer is formed on the other surface of the base material, and a dye layer is formed on the undercoat layer. The undercoat layer is a group consisting of an alkoxide, a hydrolyzate thereof, and tin chloride. A thermal transfer recording medium, comprising at least one selected from vinyl pyrrolidone-vinylimidazole copolymer, a water-soluble polymer, and a water-dispersible polyester as main components.   The thermal transfer image-receiving sheet base material is any one of synthetic paper made of polypropylene or polystyrene, synthetic paper made of a composite material obtained by bonding polypropylene or polystyrene to paper, paper, or coated paper. recoding media.   A heat-sensitive transfer recording medium, wherein the hollow particles of the hollow particle layer of the thermal transfer image-receiving sheet are any one of acrylonitrile, vinylidene chloride and styrene acrylate polymer.   The receiving layer of the thermal transfer image receiving sheet is a vinyl chloride resin, urethane resin, polyester resin, polycarbonate resin, polyvinyl acetal resin, polyvinyl butyral resin, polystyrene resin, polyacrylate resin, acrylic resin, cellulose resin, A thermal transfer recording medium, characterized in that it is any one of a polyamide resin, a copolymer resin of a vinyl compound monomer and a monomer having a benzotriazole skeleton and / or a benzophenone skeleton.

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