JP2008296485A - Thermal transfer receptive sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal transfer recipient sheet which excels in the peeling property between an ink sheet and a recipient layer at the time of high-speed print and in which the light stability of images is excellent. <P>SOLUTION: The thermal transfer recipient sheet comprises laminating an image recipient layer and a mold release layer one by one on at least one surface of a support sheet, and is characterized in that the image recipient layer is formed using an aqueous coating liquid making a dyeing property thermoplastic resin as a principal component, and the mold release layer is formed using an aqueous coating liquid which at least contains a release agent and an ultraviolet absorption agent. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a receiving sheet that is excellent in peelability between a dye thermal transfer sheet and a thermal transfer receiving sheet (hereinafter also simply referred to as a receiving sheet) and has good light fastness for images even during high-speed printing.

  The dye thermal transfer system includes a dye thermal transfer sheet (hereinafter simply referred to as an ink ribbon) having a dye layer containing a dye that sublimes and migrates by heat, and an image receiving layer (hereinafter simply referred to as an ink ribbon). The receiving sheet having a receiving layer) is superposed, the dye layer and the receiving layer are overlapped, and the dye at a required portion of the dye layer is transferred onto the receiving layer by a predetermined concentration by heat supplied from a thermal head or the like. To form an image.

  As dye dyeing resins used for the receiving layer, highly oleophilic thermoplastic resins such as vinyl chloride resins, polyester resins, polyvinyl butyral resins, acrylic resins, and cellulose resins have been proposed (for example, , See Patent Documents 1-3). In general, the receptor layer is prepared by preparing a receptor layer coating solution obtained by dissolving the above thermoplastic resin in an organic solvent such as toluene, methyl ethyl ketone, etc., and applying this onto a sheet-like support, followed by drying and volatilizing the organic solvent. Forming a layer. However, as a manufacturing apparatus, an explosion-proof drying apparatus or a large-scale apparatus for recovering the organic solvent is required, which contributes to an increase in manufacturing cost. In recent years, the environmental burden due to the use of organic solvents has become a social problem, and removal of organic solvents is also desired in the production of receiving sheets.

  For making the receiving layer coating liquid aqueous, it has been proposed to use a hydrophilic thermoplastic resin such as an aqueous dispersion of a polyester resin (see, for example, Patent Document 4). As compared with the case where a thermoplastic resin is used, there is a defect that the dyeing property of the receiving layer is inferior. To compensate for this drawback, the composition of the thermoplastic resin in the receiving layer is changed to lower the glass transition point, a thermoplastic resin having a low glass transition point is used in combination, or a plasticizer is added to the receiving layer. However, in this case, the releasability of the ink ribbon and the receiving layer deteriorates, and when an image is formed with a recent high-speed printer, the ink ribbon and the receiving layer are fused to cause poor printing. May occur.

  In order to improve the releasability between the ink ribbon and the receiving layer, a method of providing a releasing layer on the surface of the receiving layer is effective. For example, a method of applying a lipophilic release agent as a release agent (see, for example, Patent Document 5 or 6), a method of applying a lipophilic thermoplastic resin containing a release agent on a hydrophilic receiving layer ( For example, refer to Patent Document 7), and a method of applying a hydrophilic thermoplastic resin in which a release agent is blended on a lipophilic receiving layer (for example, refer to Patent Document 8) has been proposed. The density is low and no consideration is given to the light stability of the image.

  In order to improve the light stability, for example, a method of adding a benzotriazole-based UV absorber or a hindered amine-based light stabilizer to the receiving layer has been proposed (for example, Patent Document 9 or 10). However, in order to obtain a sufficient effect, a large amount of addition is necessary, which increases the manufacturing cost of the receiving sheet and requires improvement.

  Furthermore, a receiving sheet is disclosed in which an overlayer containing a silicon resin and a polymer type ultraviolet absorber is provided on the receiving layer (see, for example, Patent Document 11). However, in order to obtain a sufficient effect, it is necessary to increase the thickness of the over layer, which causes a decrease in print density. In addition, due to the remaining organic solvent such as methyl ethyl ketone, toluene, or isopropyl alcohol used at the time of forming the receiving layer or the over layer, the ink ribbon is fused at the time of high-speed printing, etc. Further, there is a problem that a sufficient light resistance improvement effect cannot be obtained due to reverse transfer of the ultraviolet absorber onto the ribbon.

JP-A-2-38092 (first page) JP-A-63-7971 (first page) Japanese Patent Laid-Open No. 7-117371 (2nd page) JP-A-6-24156 (page 2) Japanese Patent Laid-Open No. 3-146395 (first page) JP-A-1-159289 (first page) JP-A-5-58061 (2nd page) JP-A-5-58060 (2nd page) JP-A-8-267936 (2nd page) JP 2000-309170 A (second page) Japanese Patent Laid-Open No. 11-48626 (page 2)

  An object of the present invention is to improve the above-mentioned drawbacks of the prior art, and to provide a receiving sheet that is excellent in peelability between an ink sheet and a receiving layer even during high-speed printing and has good light fastness of images.

(1) In a thermal transfer receiving sheet in which an image receiving layer and a release layer are sequentially laminated on at least one surface on a sheet-like support, the image receiving layer is an aqueous coating solution mainly composed of a dyeable thermoplastic resin. A thermal transfer receiving sheet, wherein the release layer is formed using an aqueous coating solution containing at least a release agent and an ultraviolet absorber.
(2) The thermal transfer receiving sheet according to item (1), wherein a porous layer is further formed between the sheet-like support and the image receiving layer.
(3) In the item (1) or (2), the sheet-like support is a sheet-like support in which a thermoplastic resin layer is formed on at least one surface of a paper base material mainly composed of cellulose pulp. The thermal transfer receiving sheet described.
(4) The thermal transfer receiving sheet according to any one of (1) to (3), which contains a polyester resin as the dyeable thermoplastic resin component.
(5) The thermal transfer receiving sheet according to any one of (1) to (4), wherein the release agent is a silicone graft acrylic copolymer.
(6) The ultraviolet absorber is a (meth) acrylic copolymer having a benzotriazole skeleton in the side chain and / or a (meth) acrylic copolymer having a benzophenone skeleton in the side chain. The thermal transfer receiving sheet according to any one of (5).
(7) The thermal transfer receiving sheet according to any one of items (1) to (6), wherein the ultraviolet absorber is an emulsion having a structure in which an ultraviolet absorber is coated with a resin.

  The receiving sheet of the present invention is a receiving sheet having excellent peelability between the ink sheet and the receiving layer even during high-speed printing, high printing density, and good light fastness of the image, and thermal transfer including a sublimation thermal transfer system. This is useful for full-color printers.

The present invention relates to a thermal transfer receiving sheet in which an image receiving layer and a release layer are sequentially laminated on at least one surface of a sheet-like support, and the receiving layer uses an aqueous coating liquid mainly composed of a dyeable thermoplastic resin. The release layer is formed using an aqueous coating solution containing a release agent and an ultraviolet absorber.
The present invention is described in detail below.

(Sheet support)
As the base material for sheet-like support in the present invention, papers mainly composed of cellulose pulp, synthetic resin films and the like are used. For example, paper such as high-quality paper (acidic paper, neutral paper), medium-quality paper, coated paper, art paper, glassine paper, or synthetic resins such as polyolefin such as polyethylene and polypropylene, polyester such as polyethylene terephthalate, etc. Examples of the component include films and sheets, porous single-layer stretched films, and porous multilayer stretched films (for example, synthetic paper).

  As the sheet-like support, these substrates may be used alone, or a laminate in which these films or these films and other films and / or papers are appropriately laminated and pasted. Used. Moreover, the laminated body which provided the coating layer containing adhesive resin in the said base material as needed can also be used preferably.

  In the present invention, among the above-mentioned base materials, papers mainly composed of cellulose pulp are advantageous in terms of cost, and are preferably used because the texture of the obtained receiving sheet is close to photographic paper.

  Further, as the sheet-like support, it is also possible to use a paper base material in which a thermoplastic resin layer is formed at least on the side where the receiving layer is formed. By providing a thermoplastic resin layer on the paper substrate, the flatness of the surface on which the porous layer is formed is improved, and it is possible to prevent the coating liquid for forming the porous layer from penetrating into the paper substrate. A uniform porous layer can be obtained.

  Although it does not specifically limit as resin used for a thermoplastic resin layer, Specifically, Polyolefin resin, such as polyethylene and a polypropylene, a polyester resin, (meth) acrylic acid ester resin, a polystyrene-type resin, a polyurethane resin, a polycarbonate resin , Polyvinyl chloride resins, vinyl chloride-vinyl acetate copolymer resins, polyvinyl acetal resins, polyvinyl butyral resins, cellulose derivative resins such as cellulose acetate butyrate, polyamide resins, and the like. Among these resins, polyolefin resins such as polyethylene and polypropylene are preferably used.

  Moreover, about the formation method of a thermoplastic resin layer, for example, (1) The method of coating and drying and forming the coating liquid containing a thermoplastic resin on a base material, or (2) Containing a thermoplastic resin Although the method of melt-extruding and laminating the molten resin composition to form on a base material is mentioned, it is not specifically limited. In addition, when using polyolefin-type resin as a thermoplastic resin, it is preferable that a thermoplastic resin layer is formed by a melt-extrusion lamination system.

When using a paper base material or a paper base material on which a thermoplastic resin layer is formed as the sheet-like support of the present application, it is preferable to provide a porous layer on the paper base material or thermoplastic resin layer. . Although the formation method of a porous layer is not specifically limited, For example, the following porous layers are mentioned by the formation method.
(1) A porous layer in which air bubbles are fixed by foaming a paint containing an adhesive resin by mechanical stirring and coating and drying a coating liquid containing air bubbles in the paint on a sheet-like support.
(2) A coating liquid in which an adhesive resin and a foaming agent (for example, a chemical decomposition type or a thermal decomposition type) are mixed is applied onto a sheet-like support, dried or dried, and further heated strongly to foam the foaming agent. Porous layer.
(3) The adhesive resin is less likely to evaporate than an organic solvent (for example, a hydrophilic solvent such as methyl ethyl ketone or alcohol) and the organic solvent, and is compatible with the organic solvent. Is a porous layer in which a mixed solution with a non-solvent having no solubility (for example, water) is coated on a sheet-like support and dried to form a micro-aggregated layer.
(4) A porous layer formed by coating and drying on a sheet-like support a coating liquid in which primary particles and / or secondary aggregated particles of an inorganic white pigment are dispersed in an adhesive resin.
(5) A porous layer formed by applying a coating liquid containing an adhesive resin and organic and / or inorganic hollow particles onto a sheet-like support and drying (further heating and foaming as necessary). .

  Among these porous layer formation methods, the hollow particles of (5) are selected from the viewpoints of surface flatness of the porous layer, reproducibility in the production of the porous layer, sensitivity of the obtained receiving sheet and image uniformity. The containing porous layer is preferably formed. By providing a porous layer containing hollow particles on a sheet-like support mainly composed of a paper substrate, the receiving sheet is provided with heat insulation and cushioning properties, so that the density of the receiving sheet is increased and image uniformity is increased. Is improved, and is a particularly preferable form as a receiving sheet.

  The material and manufacturing method of the hollow particles used in the porous layer are not particularly limited. Specifically, the materials for forming the walls of the hollow particles include acrylonitrile, methacrylonitrile, vinylidene chloride, styrene, (meth ) Homopolymers such as acrylic esters, copolymers thereof, and mixtures of these homopolymers. Examples of a method for producing these hollow particles include a method in which a polymer in which butane gas is encapsulated in resin particles is heated and foamed, a method in which the polymer is produced by an emulsion polymerization method, and the like.

(Receptive layer)
As the resin for forming the receiving layer, a thermoplastic resin having high affinity for the dye transferred from the ink ribbon and having good dye dyeing property (also called dyeing thermoplastic resin) is generally used. Examples of such a dyeable thermoplastic resin include polyester resin, polyurethane resin, polycarbonate resin, polyvinyl chloride resin, vinyl chloride-vinyl acetate copolymer resin, polyvinyl acetal resin, polyvinyl butyral resin, polystyrene resin, and polyacrylic acid. Examples thereof include, but are not limited to, ester derivatives, cellulose derivative resins such as cellulose acetate butyrate, and thermoplastic resins such as polyamide resins. Among these, polyester resins, polyurethane resins, polyacrylate resins, and vinyl chloride-vinyl acetate copolymers that are excellent in dyeing properties are preferably used, and polyester resins are particularly preferably used. These dyeable thermoplastic resins may be used alone or in combination of two or more.

  In the present invention, the receiving layer coating solution is characterized by being aqueous, but the dyeable thermoplastic resin may exist in a state dissolved in water or in a state dispersed in water. May be. A known technique can be used for water-solubilizing the dyeable thermoplastic resin. For example, a carboxyl group, a phosphate group, a sulfone group, an amino group, an imino group, a first group, Generally, a method of introducing a triamine group, a hydroxyl group, an ether group, an amide group, etc., neutralizing with a counter ion, forming a hydrophilic soap or ionic group, and dissolving it in water is of course used. It is not limited. In the case of water dispersion, a known technique such as an emulsion polymerization method can be used. As the dyeable thermoplastic resin, it is possible to use a water-soluble thermoplastic resin alone, a water-dispersible thermoplastic resin alone, or a combination of the two.

  The dyeable thermoplastic resin preferably has a reactive functional group (for example, a functional group such as a hydroxyl group, an amino group, a carboxyl group, or an epoxy group). In addition, a crosslinking agent such as a polyisocyanate compound, an epoxy compound, an oxazoline compound, a carbodiimide compound, or an organometallic compound is blended in the coating solution for the receiving layer, and reacted with the functional group of the above-described dyeable thermoplastic resin for dyeing. It is also possible to three-dimensionally crosslink the thermoplastic resin. The crosslinking agent is preferably blended so that the functional group number of the crosslinking agent is about 0.1 to 1,000 with respect to the functional group number 1 of the dyeable thermoplastic resin.

  In addition, for the purpose of controlling dyeability, a plasticizer can be used alone or in combination. As the plasticizer, known phthalates, aliphatic dibasic esters, trimellitic esters, phosphate esters, epoxies, polyesters, and the like can be used. As a compounding quantity of a plasticizer, about 1-50 mass parts is preferable with respect to 100 mass parts of the dyeable thermoplastic resin of a receiving layer, and 1-30 mass parts is more preferably used from balance with bleed-out. It is done.

  In order to further improve the light resistance, an ultraviolet absorber (hereinafter referred to as UVA), a hindered amine light stabilizer (hereinafter referred to as HALS), and an antioxidant are also incorporated in the receiving layer in addition to the release layer. The agents can be used alone or in combination. As a compounding quantity, 1-70 mass parts is mix | blended with respect to 100 mass parts of dyeable thermoplastic resins of a receiving layer, and the compounding of 1-40 mass parts is used preferably.

The solid coating amount of the receiving layer is preferably about 1 to 12 g / m ² , more preferably ² to 10 g / m ² . Incidentally, if the solid content coating amount of the receiving layer is less than 1 g / m ² , the receiving layer cannot completely cover the support surface, resulting in deterioration of the image quality, or heating of the thermal head and the receiving layer and the ink. There may be a fusing problem that the ribbon adheres. On the other hand, if the solid coating amount of the receiving layer exceeds 12 g / m ² , not only is the effect saturated and uneconomical, but also the strength of the receiving layer is insufficient or the thickness of the receiving layer increases and the support is increased. The heat insulation effect is not sufficiently exhibited, and the image density may be lowered.

(Release layer)
Further, the present invention provides a release layer formed using an aqueous coating solution containing at least a release agent and an ultraviolet absorber on the receiving layer for the purpose of improving the peelability from the ink ribbon and improving the light resistance of the image. It is a feature. The water-based coating solution has a very small coating amount and is not adversely affected by the residual organic solvent, etc., and even during high-speed printing, the ink ribbon and the receiving sheet are prevented from being fused, and the running property is good. In addition, reverse transfer of the UV absorber to the ink ribbon is prevented, and a sufficient light resistance improvement effect is obtained.

  The release agent that can be used in the present invention is not particularly limited. Specifically, epoxy-modified silicone oil, epoxy-polyether-modified silicone oil, alcohol-modified silicone oil, polyether-modified silicone oil, amino Modified silicone oil such as modified silicone oil, carboxyl modified silicone oil, methacrylic acid modified silicone oil, unmodified silicone oil such as dimethyl silicone oil, silicone graft copolymer resin, paraffin wax, polyethylene such as fluorocarbon, stearin Examples of the releasing agent include fatty acids such as acids, aliphatic amides, esters, alcohols, metal soaps, and natural waxes.

  In addition, in order to make these release substances water-soluble, the release agent skeleton or the functional group of the side chain is neutralized with a counter ion to form a hydrophilic soap or ionic group and dissolve in water. It is possible to use a known technique such as a water dispersion technique such as a liquefaction technique, a mechanical emulsification method, or an emulsion polymerization method, but of course not limited thereto.

  Of these release agents, silicone graft copolymer resins that exhibit good water solubility, excellent release performance with the ribbon, and excellent adhesion with the receiving layer are preferably used. Examples of the silicone graft copolymer resin include those obtained by graft polymerization of silicone on an acrylic resin, a urethane resin, a polyester resin, a polyamide resin, and the like, and a silicone graft acrylic copolymer resin is particularly preferably used. When a conventionally known silicone oil is used as a release agent, the adhesion between the receiving layer and the substrate may be lowered.

  In the silicone graft acrylic resin, the main chain acrylic polymer maintains adhesion to the substrate, and the side chain polysiloxane imparts releasability. As a method for synthesizing a silicone graft acrylic resin, there are (1) a method of reacting an acrylic polymer with polysiloxane, and (2) a method of reacting polysiloxane simultaneously with a polymerization reaction of an acrylic monomer.

  As a specific example of the synthesis method, a hydroxyl group-containing polysiloxane, a polymerizable silane compound, an unsaturated organic acid, and a polymerizable acrylic monomer are polymerized in an organic solvent, and the resulting polymer solution is basic. A silicone-grafted acrylic resin can be obtained by adding a compound, but it is not limited to this. Examples of the hydroxyl group-containing polysiloxane include dimethylpolysiloxane, methylethylpolysiloxane, methylphenylpolysiloxane, and diphenylpolysiloxane.

  Examples of the polymerizable silane compound include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, allyltriethoxysilane, and vinyltris (β-methoxyethoxy) silane. Examples of the unsaturated organic acid include acrylic acid, methacrylic acid, maleic acid, vinyl sulfonic acid, and 2-acrylamido-2-methylpropane sulfonic acid. Polymerizable acrylic monomers include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, (meth) Examples include 2-hydroxypropyl acrylate.

  Examples of the basic compound include sodium hydroxide, ammonia, trimethylamine, triethylamine, monomethyloldimethylamine and the like. In addition to acrylic monomers, monomers such as styrene, acrylonitrile, acrylamide, ethylene, propylene, vinyl acetate, and vinyl chloride can be added as appropriate. Moreover, radical polymerization initiators such as azobisisobutyronitrile and benzoyl peroxide can be used as the polymerization initiator. By adjusting the amount of the unsaturated organic acid in the composition, it can be finished into a water-dispersible resin or a water-soluble resin.

  Although it does not specifically limit as an ultraviolet absorber used in the mold release layer of this invention, The ultraviolet absorbers, such as a benzotriazole type, a triazine type, an oxalic acid anilide type, a benzophenone type, are used preferably. In particular, benzotriazole has a broad absorption wavelength range compared to other ultraviolet absorbers, has a maximum absorption peak on the high wavelength side, and has a large absorbance, so that particularly excellent effects can be obtained when used in combination with HALS. Therefore, it is preferably used. Generally known lipophilic UV absorbers can also be used, but since the UV absorber is easy to separate in the water-based release layer coating and it is difficult to obtain a uniform coating film, an emulsifier or the like is used in advance with the aqueous dispersion. It is preferable to use what was done.

  As another form of the ultraviolet absorber, the ultraviolet absorber may be a benzotriazole skeleton acting as an ultraviolet absorber, or an aqueous (meth) acrylic copolymer having a benzophenone skeleton in the side chain. The aqueous (meth) acrylic resin is composed of an ultraviolet-absorbing monomer such as a polymerizable vinyl compound to which a 2-hydroxybenzophenone residue or 2-hydroxybenzotriazole residue is bonded, and a (meth) acrylic acid ester copolymerizable with this monomer. And a vinyl compound monomer such as tolylamine and a crosslinkable monomer such as tolylamine. It is preferably used because the molecular weight is higher than that of using an aqueous dispersion of an ultraviolet absorber, and therefore there is little bleeding out and the ultraviolet absorber is difficult to reversely transfer to the ribbon during printing.

  Moreover, the core shell type emulsion which has the structure which coat | covered the said ultraviolet absorber with the acrylic resin etc. may be sufficient. The core-shell emulsion is synthesized by neutralizing a water-soluble resin obtained by various synthesis methods with amine or ammonia, and dropping a hydrophobic monomer solution in which an ultraviolet absorber is dissolved in a solution dispersed in water. The At this time, the hydrophobic monomer containing the UV absorber gradually enters and polymerizes in the shell polymer dispersed in water, so that the UV absorber is stably fixed in the emulsion and there is no bleed out. In addition, an ultraviolet absorber is preferably used because it is difficult to reverse transfer.

  Also, the release layer of the present invention can be blended with a crosslinking agent such as a polyisocyanate compound, epoxy, oxazoline, carbodiimide, or organometallic compound, or a water-soluble thermoplastic resin or a water-dispersed thermoplastic resin can be used in combination. It is.

The mixing ratio of the release agent and the ultraviolet absorber in the release layer of the present invention is not particularly limited, but the release agent is 20 to 80% by mass with respect to the total solid mass of the release layer. It is preferable to mix within the range. When the blending ratio of the release agent is less than 20% by mass, the releasability with the ink ribbon is not sufficient, whereas when the blending ratio of the release agent exceeds 80% by mass, the ultraviolet absorption effect cannot be sufficiently obtained. The coating amount of the release layer is preferably from 1-10 mg / ^{m 2,} more preferably 2-5 mg / ^{m 2.} If the coating amount of the release layer is less than 1 mg / m ² , the effect of improving the peelability from the ink ribbon may be insufficient. On the other hand, if it exceeds 10 mg / m ² , the release layer is formed on the receiving layer. At the time of formation, the receiving layer dissolves and a uniform release layer cannot be obtained, the printing density is lowered, or a problem occurs in the transfer property of the protective layer of the ink ribbon.

(Barrier layer)
A barrier layer is preferably provided between the porous layer having hollow particles and the receiving layer. The barrier layer is effective as a barrier for preventing the phenomenon that the dye dyed on the receiving layer diffuses and migrates to the porous layer over time, so-called image blurring, back-through, and the like.

  As the resin used for the barrier layer, a resin having excellent film forming ability, elasticity and flexibility is used. Specifically, starch, modified starch, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, gelatin, casein, gum arabic, fully saponified polyvinyl alcohol, partially saponified polyvinyl alcohol, carboxy modified polyvinyl alcohol, acetoacetyl group modified polyvinyl alcohol, isobutylene -Maleic anhydride copolymer salt, styrene-maleic anhydride copolymer salt, styrene-acrylic acid copolymer salt, ethylene-acrylic acid copolymer salt, urea resin, urethane resin, melamine resin, amide resin, etc. A water-soluble resin is used.

  Also, water-dispersible resins such as styrene-butadiene copolymer latex, acrylic ester resin latex, methacrylic ester copolymer latex, ethylene-vinyl acetate copolymer latex, polyester polyurethane ionomer, polyether polyurethane ionomer, etc. Can also be used. Among the above resins, water-soluble resins are preferably used. Moreover, said resin may be used independently or may use 2 or more types together.

  Furthermore, the barrier layer may contain various pigments, preferably a swellable inorganic layered compound is used, which is excellent not only in preventing penetration of the coating solvent but also in preventing blurring of the thermal transfer dyed image. An effect is obtained. Examples of the swellable inorganic layered compound include synthetic mica such as fluorine phlogopite, potassium tetrasilicon mica, sodium tetrasilicon mica, sodium teniolite, lithium teniolite, or sodium hectorite, lithium hectorite, saponite, etc. Smectite is more preferably used. Among these, sodium tetrasilicon mica is particularly preferable, and a desired particle size, aspect ratio, and crystallinity can be obtained by a fusion synthesis method.

(Back layer)
In the receiving sheet of the present invention, on the surface (back surface) of the sheet-like support on which the receiving layer is not provided, the running property is improved, the static electricity is prevented, the receiving layer is prevented from being damaged by rubbing between the receiving sheets, When the printed receiving sheet is placed on top of each other, a back layer may be formed for the purpose of preventing dye transfer from the receiving layer to the back surface of the receiving sheet adjacent to the receiving layer. A resin as an adhesive component and various conductive agents can be added to the back layer for antistatic treatment. As the conductive agent, it is preferable to use a cationic polymer. As the cationic polymer, polyethyleneimine, an acrylic polymer containing a cationic monomer, a cation-modified acrylamide polymer, a cationic starch, or the like can be generally used.

  In the present invention, in particular, when using a sheet-like support provided with a porous layer containing hollow particles, the receiving sheet may be subjected to a calendering treatment to reduce and smooth the unevenness of the receiving layer surface. Things are also possible. For example, when paper is used as the sheet-like support, the calendar treatment may be performed at any stage after the porous layer, the barrier layer, or the receiving layer is applied. There are no particular limitations on the calendar device used for the calendar process, the nip pressure, the number of nips, the surface temperature of the metal roll, etc., but the pressure condition when performing the calendar process is preferably 0.5 to 50 MPa. More preferably, it is 1-30 MPa. As for temperature conditions, 20-150 degreeC is preferable, More preferably, it is 30-130 degreeC. As the calendar device, for example, a calendar device generally used in the paper manufacturing industry such as a super calendar, a soft calendar, a gloss calendar, a clearance calendar, and the like can be appropriately used.

  The receiving layer, release layer, and other coating layers of the receiving sheet of the present invention include a bar coater, a gravure coater, a comma coater, a blade coater, an air knife coater, a gate roll coater, a die coater, a curtain coater, and a slide bead. Using a known coater such as a coater, a predetermined coating solution can be applied and dried.

  The present invention will be described in more detail with reference to the following examples, but the present invention is of course not limited thereto. Unless otherwise specified, “parts” and “%” in the examples all represent “parts by mass” and “% by mass”, and are solid amounts except for those relating to solvents.

Example 1
A multilayer structure film (trade name: YUPO FPG50, manufactured by YUPO Corporation) having a main component of biaxially stretched polypropylene is laminated on both surfaces of a high-quality paper having a thickness of 100 μm by a dry lamination method, and a sheet-like support did. Further, on the sheet-like support, a receiving layer coating solution-A having the following composition was applied and dried so that the solid content coating amount was 5 g / m ² to form a receiving layer. Further, a release layer coating liquid-1 having the following composition is applied on the receiving layer of the sheet-like support so that the solid content coating amount is 3 mg / m ² and dried to form a release layer. Then, a receiving sheet was created.

<Coating liquid for receiving layer-A>
Water-soluble polyester resin (trade name: PMD-1200, manufactured by Toyobo) 80 parts urethane resin (trade name: Neo Sticker 1200, manufactured by Nikka Chemical) 20 parts polyisocyanate (trade name: NK Assist IS-70S, manufactured by Nikka Chemical) ) 2 parts water 50 parts <Coating liquid for release layer-1>
Alcohol-modified silicone (trade name: SF8427,
50 parts water-dispersed benzotriazole UV absorber (trade name: Shineguard BZ-24, manufactured by Senka) 50 parts 50 parts water

Example 2
As a sheet-like support, art paper (trade name: OK Kanto N, 174.4 g / m ² , manufactured by Oji Paper Co., Ltd.) having a thickness of 150 μm is used, and a porous layer coating liquid-1 having the following composition is provided on one side thereof. Was coated and dried so that the film thickness after drying was 51 μm to form a porous layer. Furthermore, the barrier layer coating liquid-1 having the following composition was coated on the porous layer so that the solid content coating amount was 2 g / m ² and dried to form a barrier layer. The receiving layer coating solution-A (adjusted in Example 1) was applied and dried so that the solid content coating amount was 5 g / m ² to form a receiving layer. Further, the release layer coating solution-1 (adjusted in Example 1) was applied onto the receiving layer and dried so that the solid content coating amount was 3 mg / m ^2. To form a receiving sheet.

<Porous layer coating liquid-1>
Pre-foamed hollow particles (average particle diameter 3.2 μm, volume hollow ratio 76%) made of a copolymer mainly composed of acrylonitrile and methacrylonitrile 50 parts polyvinyl alcohol (trade name: PVA205, manufactured by Kuraray Co., Ltd.) 10 parts styrene Butadiene latex (trade name: PT1004, Nippon Zeon 40 parts water 250 parts <barrier layer coating liquid-1>
Swellable inorganic layered compound (sodium 4 silicon mica, particle average major axis 6.3 μm,
Aspect ratio 2700) 30 parts polyvinyl alcohol (trade name: PVA105, manufactured by Kuraray) 50 parts styrene-butadiene latex (trade name: L-1537, manufactured by Asahi Kasei) 20 parts water 1100 parts

Example 3
As a sheet-like support, high-quality paper with a thickness of 150 μm is used, low-density polyethylene resin (product name: Novatec LC520, made by Nippon Polyethylene) is 20 μm on one side, and high-density polyethylene resin (product name: Novatec) is on the other side HF560 (manufactured by Nippon Polyethylene) was melt extruded and laminated to a thickness of 30 μm to form a sheet-like support, and a porous layer was formed on a low-density polyethylene resin. Created a sheet.

Example 4
A receiving sheet was prepared in the same manner as in Example 3 except that the release layer coating solution-2 having the following composition was used instead of the release layer coating solution-1.
<Release layer coating solution-2>
Silicone graft acrylic resin (trade name: Cymac US-450,
50 parts water-dispersed benzotriazole UV absorber (trade name: Shineguard BZ-24, manufactured by Senka) 50 parts water 50 parts

Example 5
A receiving sheet was prepared in the same manner as in Example 3 except that the release layer coating solution-3 having the following composition was used instead of the release layer coating solution-1.
<Release layer coating solution-3>
Silicone graft acrylic resin (trade name: Cymac US-450,
50 parts of benzotriazole UV absorber graft type acrylic resin (trade name: ULS1700, manufactured by Yushi Co., Ltd.) 50 parts Water 50 parts

Example 6
A receiving sheet was prepared in the same manner as in Example 3 except that the release layer coating solution-4 having the following composition was used instead of the release layer coating solution-1.
<Coating liquid for release layer-4>
Silicone graft acrylic resin (trade name: Cymac US-450,
50 parts by benzotriazole type UV absorber-encapsulated core cell type acrylic emulsion (trade name: SE2538, manufactured by Taisei Fine Chemical) 50 parts by water 50 parts

Comparative Example 1
A receiving sheet was prepared in the same manner as in Example 3 except that the receiving layer coating solution-B having the following composition was used in place of the receiving layer coating solution-A and no release layer was provided.
<Coating liquid for receiving layer-B>
Water-soluble polyester resin (trade name: PMD-1200, manufactured by Toyobo) 78 parts urethane resin (trade name: Neo sticker 1200, manufactured by Nikka Chemical) 20 parts alcohol-modified silicone oil (trade name: SF8427,
Toray Dow Corning) 2 parts polyisocyanate (trade name: NK Assist IS-70S, Nikka Chemical) 2 parts water 50 parts

Comparative Example 2
Instead of the receiving layer coating liquid-A, the receiving layer coating liquid-C having the following composition, the release layer coating liquid-5 instead of the releasing layer coating liquid-1, the solid coating amount A receiving sheet was prepared in the same manner as in Example 3 except that a release layer was formed by coating and drying so that the weight was 1 g / m ² .
<Coating liquid for receiving layer-C>
Polyester resin (trade name: Byron 200, manufactured by Toyobo) 98 parts polyisocyanate (trade name: Takenate D110N,
Mitsui Chemicals Polyurethane) 2 parts 50 parts water <Release layer coating solution-5>
Water-soluble polyester resin (trade name: PMD-1200, manufactured by Toyobo Co., Ltd.) 85 parts carboxy-modified silicone microemulsion (trade name: X-51-789, manufactured by Shin-Etsu Silicone) 6 parts polyfunctional aziridine derivative compound (trade name: Chemite) P-33,
Nippon Shokubai Chemical) 9 parts water 85 parts

Comparative Example 3
Except that the release layer coating liquid-6 was applied in place of the release layer coating liquid-1 so that the solid content coating amount was 1 g / m ² and dried to form a release layer. A receiving sheet was prepared in the same manner as in Example 3.
<Coating liquid for release layer-6>
Polyester resin (trade name: Byron 200, manufactured by Toyobo) 20 parts amino-modified silicone oil (trade name: KF-393, manufactured by Shin-Etsu Chemical) 2 parts polyisocyanate (trade name: Takenate D110N,
Mitsui Chemicals Polyurethane) 2 parts 100% methyl ethyl ketone

Comparative Example 4
A receiving sheet was prepared in the same manner as in Example 4 except that the release layer coating solution-7 having the following composition was used instead of the release layer coating solution-2.
<Release layer coating solution-7>
Silicone graft acrylic resin (trade name: Cymac US-450,
100 parts water 50 parts

Comparative Example 5
In place of the receiving layer coating liquid-A, a receiving layer coating liquid-C having the following composition was used. Instead of the releasing layer coating liquid-2, the release layer coating liquid-7 (comparison) A receiving sheet was prepared in the same manner as in Example 4 except that the adjustment in Example 4 was used.
<Coating liquid for receiving layer-C>
Aqueous polyester resin (trade name: PMD-1200, manufactured by Toyobo Co., Ltd.) 68 parts urethane resin (trade name: Neo Sticker 1200, manufactured by Nikka Chemical Co., Ltd.) 10 parts Water-dispersible UV absorber (trade name: Shineguard BZ-24, 20 parts polyisocyanate (trade name: NK Assist IS-70S, manufactured by Nikka Chemical) 2 parts water 50 parts

Evaluation The following tests were conducted on the receiving sheets obtained in the above Examples and Comparative Examples. The obtained results are shown in Table 1.

(Print density)
Using the commercially available thermal transfer video printer (trade name: UP-50, manufactured by Sony Corporation) equipped with a sublimation type thermal transfer ink ribbon (trade name: UP-540, manufactured by Sony Corporation) A recording image of 16 gradations according to applied energy was printed. The reflection density was measured using a Macbeth reflection densitometer (trade name: RD-914, manufactured by Kollmorgen). The reflection density of the high gradation portion corresponding to the 15th step from the lowest applied energy is displayed in Table 1 as the print density. If the print density is 2.0 or more, it is sufficiently suitable for practical use.

[Ink ribbon peelability test]
Using the commercially available thermal transfer video printer (trade name: UP-50, manufactured by Sony Corporation) equipped with a sublimation type thermal transfer ink ribbon (trade name: UP-540, manufactured by Sony Corporation) on the obtained receiving sheet, 50 ° C. Under the environment, the head temperature at the start of printing was adjusted to 50 ° C., and 10 black solid images were printed continuously. At that time, the fusing state between the receiving sheet surface and the ink ribbon as the printability, the discharge property of the receiving sheet from the printer, and the like were evaluated according to the following criteria, and the ribbon peelability is shown in Table 1.
A: There is no fusion between the receiving sheet surface and the ink ribbon, and 10 sheets are normally discharged continuously, and there is no problem in practical use.
Δ: Some noise is caused by light fusion between the receiving sheet surface and the ink ribbon, but all 10 sheets are discharged and are practical.
X: The receiving sheet surface and the ink ribbon are fused, and there are some which are not normally discharged, which is not suitable for practical use.

(Light resistance test)
The black solid image print obtained above was processed with an Xe fade meter until the accumulated illuminance reached 10,000 kJ / m ² . The color tone before and after the light resistance test of the image was measured using a color difference meter (Gretag) in accordance with JIS Z 8721. The measured values were recorded in the L * a * b * color system based on JIS Z 8729, and the color difference (ΔE *) before and after processing was calculated by the method based on JIS Z 8730. If the color difference is 13 or less, it is a level with no practical problem.

  The receiving sheet of the present invention has excellent peelability between the ink ribbon and the receiving layer, and further has excellent light resistance of the image, and is useful for various color transfer printers such as sublimation thermal transfer systems. The place that contributes to

Claims (7)

  In a thermal transfer receiving sheet in which an image receiving layer and a release layer are sequentially laminated on at least one surface of a sheet-like support, the image receiving layer uses an aqueous coating liquid mainly composed of a dyeable thermoplastic resin. A thermal transfer receiving sheet, wherein the release layer is formed using an aqueous coating solution containing at least a release agent and an ultraviolet absorber.   The thermal transfer receiving sheet according to claim 1, wherein a porous layer is further formed between the sheet-like support and the image receiving layer.   The thermal transfer receiving sheet according to claim 1 or 2, wherein the sheet-like support is a sheet-like support in which a thermoplastic resin layer is formed on at least one surface of a paper base material mainly composed of cellulose pulp.   The thermal transfer receiving sheet according to any one of claims 1 to 3, comprising a polyester resin as the dyeable thermoplastic resin component.   The thermal transfer receiving sheet according to any one of claims 1 to 4, wherein the release agent is a silicone graft acrylic copolymer.   The ultraviolet absorber is a (meth) acrylic copolymer having a benzotriazole skeleton in the side chain and / or a (meth) acrylic copolymer having a benzophenone skeleton in the side chain. The thermal transfer receiving sheet according to 1.   The thermal transfer receiving sheet according to claim 1, wherein the ultraviolet absorber is an emulsion having a structure in which an ultraviolet absorber is coated with a resin.