JPH11348438A - Laser thermal transfer recording material and method for laser thermal transfer recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser thermal transfer recording material for rapidly recording by preventing a damage of a photothermal conversion layer itself by a laser beam, and preventing a decrease in a printing sensitivity with excellent clarity of a recorded image. SOLUTION: The laser thermal transfer recording material is obtained by sequentially laminating a photothermal conversion layer containing at least a near infrared absorbing material and a binder resin as main bodies and a thermal transfer ink layer in this order on a base material in such a manner that the resin having a glass transition temperature of 100 deg.C or higher is used. Thus, the thermal transfer recording material having a high heat resistance of the conversion layer, no softening even at the time of outputting a high output laser beam and high sensitivity is obtained. Further, when a carbon black of an inorganic particle material is used as the absorbing material, a suitable foil durability and high heat resistance can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording material used for thermal transfer of a heat mode laser system, and more particularly, to a laser thermal transfer recording material which is excellent in clarity of a recorded image, high thermal sensitivity in recording, and the like. It is about.

[0002]

2. Description of the Related Art A thermal head is brought into close contact with a surface of a thermal transfer recording material having a thermal transfer ink layer provided on a substrate, and the thermal energy is transferred to the thermal transfer ink layer by transferring thermal energy to the thermal transfer ink layer. Is widely known, and is applied to facsimile machines, printers, and the like. However, in such a thermal transfer recording method, since the thermal head is brought into close contact with the thermal transfer recording material for scanning, the thermal head may be worn or components of the thermal transfer recording material may adhere to the surface of the thermal head as scum. As a result, a recorded image may not be obtained correctly or the thermal head may be damaged. In addition, the thermal transfer recording method using such a thermal head has limitations in high-speed control of heating / cooling of the heating elements and in increasing the density of the heating elements due to the structural characteristics of the thermal head. There is a drawback that there is a limit in achieving recording, high-density recording, and high-quality recording.

In order to solve the above-mentioned disadvantages of the thermal transfer recording system using a thermal head, a laser beam is used,
It has been proposed to perform high-speed and high-density thermal recording on a thermal transfer recording material in a non-contact manner (see, for example,
No. 23617, JP-A-54-121140, JP-A-57-11090, JP-A-58-56890, JP-A-58-94494, JP-A-58-134791,
JP-A-58-145493, JP-A-59-89192
JP-A-60-205182, JP-A-62-561
No. 95).

[0004]

However, a thermal transfer recording material using a laser beam has a light-to-heat conversion layer provided on a substrate, and a resin material having low heat resistance is used as a binder for the near-infrared absorbing material of the light-to-heat conversion layer. Thus, there is a problem that the photothermal conversion layer itself is destroyed at the time of high output of the laser beam, causing image deterioration. In addition, those using a thermoplastic resin with a low glass transition temperature soften at the time of high output of laser light, so that the adhesiveness to the thermal transfer ink layer increases, and the foil holding time increases, so that the printing sensitivity is lowered. This causes a problem that the recording speed is reduced and it is difficult to increase the recording speed. Therefore, the present invention solves the above-mentioned problems, prevents the destruction of the light-to-heat conversion layer itself by laser light, is excellent in the clarity of the recorded image, and also prevents a decrease in the printing sensitivity, and is capable of high-speed recording. The purpose is to provide the material.

[0005]

In order to achieve the above object, the present invention provides a method of laminating, on a substrate, at least a photothermal conversion layer mainly composed of a near-infrared absorbing material and a binder resin, and a thermal transfer ink layer in this order. In the laser thermal transfer recording material described above, the binder resin has a glass transition temperature of 100 ° C. or higher. Preferably, the near-infrared absorbing material is carbon black. Also,
It is preferable to provide a primer layer between the substrate and the light-to-heat conversion layer. Further, it is preferable to provide a cushion layer between the substrate and the light-to-heat conversion layer. Further, it is preferable to provide a release layer between the heat conversion layer and the thermal transfer ink layer.
Further, it is preferable to provide an adhesive layer on the thermal transfer ink layer. The laser thermal transfer recording method of the present invention is characterized in that the thermal transfer ink layer of the above-mentioned laser thermal transfer recording material is brought into contact with the image receiving layer of an image receiving sheet provided with an image receiving layer on a substrate sheet, and the image receiving layer is irradiated with laser light. Transferring an image onto the layer. Further, in the laser thermal transfer recording method, it is preferable that after the image is transferred onto the image receiving layer, the image is re-transferred to an object to be transferred.

The operation of the present invention is as follows. The laser thermal transfer recording material of the present invention is obtained by laminating at least a near-infrared absorbing material, a light-to-heat conversion layer mainly composed of a binder resin, and a thermal transfer ink layer on a substrate in this order, and the binder resin has a glass transition temperature of 100 ° C. By using the above, a heat transfer recording material having high heat resistance of the light-to-heat conversion layer and not softening even at high output of laser light can be obtained. Furthermore, when carbon black, which is an inorganic particle material, is used as the near-infrared absorbing material, a suitable foil holding and high heat resistance can be achieved.

[0007]

Next, embodiments of the present invention will be described in detail. The laser thermal transfer recording material of the present invention is obtained by laminating at least a near-infrared absorbing material, a light-to-heat conversion layer mainly composed of a binder resin, and a thermal transfer ink layer on a substrate in this order, and the binder resin has a glass transition temperature of 100 ° C.
That is all. By adopting such a configuration, a heat transfer recording material can be obtained in which the heat resistance of the light-to-heat conversion layer is higher than in the past and which does not soften even at the time of high output of laser light.

(Substrate) As the substrate used in the thermal transfer recording material of the present invention, the same substrate as used in the conventional thermal transfer recording material can be used as it is, and other substrates can also be used. Although not particularly limited, when irradiating the laser light from the thermal transfer recording material side, it is preferable to use a substrate having high transparency, and it is particularly preferable that the transmittance of the wavelength of the laser light used is 60% or more. preferable.

Specific examples of preferred substrates include, for example,
Polyester such as polyethylene terephthalate, polypropylene, cellophane, polycarbonate, cellulose acetate, triacetyl cellulose, polyethylene, polyvinyl chloride, polystyrene, nylon, polyimide, polyvinylidene chloride, polyvinyl alcohol, fluororesin, chlorinated rubber, ionomer, etc. Paper with good thermal resistance, such as plastic, condenser paper, paraffin paper, etc.
There are nonwoven fabrics and the like, and a substrate obtained by combining these may be used. The thickness of the substrate can be appropriately changed depending on the material so that its strength and thermal conductivity are appropriate, but the thickness is preferably, for example, 2 to 180 μm.
In the case where an adsorption drum is used as the material holding means, 50 to 125 μm is preferable because a sufficient printing pressure can be obtained.

(Light-to-heat conversion layer) The light-to-heat conversion layer is a layer that is provided on a base material and converts laser light, which is applied to a thermal transfer recording material for recording, into heat. In the present invention, the photothermal conversion layer is mainly composed of a near-infrared absorbing material and a binder resin having a glass transition temperature of 100 ° C. or higher. Near-infrared absorbing material is a substance that absorbs light and efficiently converts it to heat.For example, when a semiconductor laser is used as a light source, specifically, carbon black, graphite, phthalocyanine-based dye, squarium-based dye, nitroso compound, and Metal complex salts, polymethine dyes, thiol nickel salts, triarylmethane dyes, immonium dyes, naphthoquinone dyes, anthracene dyes and the like can be used. Among them, carbon black, which is a particle material, is particularly preferable as the near-infrared absorbing material, since appropriate foil holding and high sensitivity of printing can be achieved.

As the binder resin for the light-to-heat conversion layer, those having a glass transition temperature of 100 ° C. or higher include polyaryl methacrylate, polybenzyl methacrylate, polymethyl methacrylate, polycarbonate, nylon, polyphenylene oxide, and the like. Examples include polyphenylene sulfide, gelatin, polyparabanic acid, polyamide, polyimide, polyvinyl acetal, polyvinyl butyral, polyvinyl formal, polyester, chlorinated polypropylene, and chlorinated polyethylene. Also, copolymers of monomer components such as styrene, vinyl chloride, methyl methacrylate, aryl methacrylate, acrylonitrile, ethylene oxide, benzyl methacrylate, and cyclohexyl methacrylate are preferably used.

By using the binder resin having a glass transition temperature of 100 ° C. or higher, the light-to-heat conversion layer has high heat resistance, does not soften even at a high output of laser light, and has good releasability from the thermal transfer ink layer. A highly sensitive thermal transfer recording material can be obtained. The light-to-heat conversion layer is formed by adding a near-infrared absorbing material as described above, a binder resin having a glass transition temperature of 100 ° C. or higher, and additives as necessary, and further adding water and an organic solvent as necessary. The coating liquid for forming a photothermal conversion layer prepared by mixing and adjusting the solvent components such as the above can be applied and dried by a conventionally known method such as gravure direct coating, gravure reverse coating, knife coating, air coating, and roll coating. The film thickness of the light-to-heat conversion layer is 0.
The content of the near-infrared absorbing material in the light-to-heat conversion layer can be usually determined so that the absorbance at the wavelength of the light source used for image recording is 0.3 to 3.0. Generally, the absorbance should be about 0.4 to 1.5.

(Thermal Transfer Ink Layer) The thermal transfer ink layer is composed mainly of a coloring material and a binder resin, and the adhesive force of the image receiving sheet with the image receiving layer is made smaller than the adhesive force with the thermal transfer recording material side by heating during printing. By becoming stronger, it is transferred to the image receiving layer side. Examples of the coloring material include pigments such as inorganic pigments and organic pigments, and dyes.
As inorganic pigments, titanium dioxide, carbon black,
Examples include zinc oxide, Prussian blue, cadmium sulfide, iron oxide, and chromates of lead, zinc, barium, and calcium. Examples of the organic pigments include azo-based, thioindigo-based, anthraquinone-based, anthranthrone-based, triphenedioxazine-based pigments, vat dye pigments, phthalocyanine pigments (eg, copper phthalocyanine) and derivatives thereof, and quinacridone pigments.

As organic dyes, acid dyes, direct dyes,
Examples include disperse dyes, oil-soluble dyes, metal-containing oil-soluble dyes, and sublimable dyes. As the sublimable dye, a conventionally known sublimable dye can be used. In the present invention, when it refers to a sublimable dye, it means a heat sublimable dye. Examples of the sublimable dye include a cyan dye, a magenta dye, and a yellow dye. The sublimable dye contained in the thermal transfer ink layer may be any one of a yellow dye, a magenta dye and a cyan dye or a mixture thereof as long as the image to be formed is a single color. The above-mentioned coloring materials have good properties as a recording material, for example, have a sufficient coloring density, light,
Those which do not discolor by heat, temperature, etc. are preferred. Also,
According to the required color tone, carbon black, an organic pigment, an inorganic pigment, or an appropriate dye can be selected from various dyes and used. The content of the coloring material in the thermal transfer ink layer is not particularly limited, but is usually in the range of 5 to 70% by weight, preferably 10 to 60% by weight.

The binder of the thermal transfer ink layer is preferably composed mainly of a resin. Specific examples of the resin include a polyester resin, an acrylic resin, an ethylene-vinyl acetate copolymer resin, and a vinyl chloride-vinyl acetate copolymer. Thermoplastic elastomers such as a polymer resin, a styrene-acrylic copolymer resin, a polyolefin resin, a polyamide resin, an ethylene-acrylic acid copolymer resin, styrene-butadiene rubber, and acrylonitrile-butadiene rubber are exemplified. Particularly, those having a relatively low softening point conventionally used as a heat-sensitive adhesive, for example, a softening point of 50 to 150 ° C are preferable.

In addition, if necessary, wax components can be mixed and used to such an extent that heat resistance and the like are not impaired. Examples of the wax include microcrystalline wax, carnauba wax, and paraffin wax. Furthermore, various types such as Fischer-Tropsch wax, various low molecular weight polyethylenes, wood wax, beeswax, spermaceti, Ibota wax, wool wax, shellac wax, candelilla wax, petrolactam, polyester wax, partially modified wax, fatty acid ester, fatty acid amide, etc. Wax. Among them, particularly, the melting point is 50
What is -85 degreeC is preferable. When the temperature is 50 ° C. or less,
A problem arises in storage stability, and if the temperature is higher than 85 ° C., the printing sensitivity becomes insufficient.

The thermal transfer ink layer is formed by adding the above-mentioned coloring material component and binder component, and if necessary, various additives such as a dispersant and an antistatic agent. A coating solution for forming a thermal transfer ink layer prepared by mixing and adjusting a solvent component such as an organic solvent, by a conventionally known method such as hot melt coating, hot lacquer coating, gravure direct coating, gravure reverse coating, knife coating, air coating, and roll coating. , Dry thickness of 0.
It is provided with a thickness of from 0.5 to 5 μm, preferably from 0.2 to 1.5 μm. When the thickness of the dried coating film is less than 0.05 μm, a uniform ink layer cannot be obtained due to the problem of film forming properties, which causes a reduction in the abrasion of printed matter. Also, when the thickness exceeds 5 μm, high energy is required at the time of print transfer,
Insufficient printing sensitivity.

(Primer layer) The laser thermal transfer recording material of the present invention can be used when the adhesiveness between the substrate and the photothermal conversion layer is weak.
By providing a primer layer between the substrate and the light-to-heat conversion layer, the adhesion between the light-to-heat conversion layer and the substrate can be enhanced. As the resin used for the primer layer, for example, an alkyd resin, a polyester resin, a polyvinyl acetate resin, a vinyl chloride-vinyl acetate copolymer resin, an NBR resin, an SBR resin, a polyurethane resin, an acrylic resin, and a polyamide alone or a mixture thereof Used as a denatured product. The modified product is, for example, a product obtained by copolymerizing or grafting a monomer containing a hydroxyl group, a carboxylic acid, or a quaternary ammonium salt to increase the adhesiveness and hydrophilicity.

In order to improve the adhesion of the primer layer and the strength of the coating film, the above resin may be crosslinked with various curing agents, for example, epoxy resin, melamine resin, isocyanate and the like. The method for forming the primer layer can be selected from the same methods as the method for forming the light-to-heat conversion layer described above.
The thickness is preferably 1 to 10 μm.

(Cushion Layer) In the laser thermal transfer recording material of the present invention, a cushion layer can be provided between the base material and the light-to-heat conversion layer. Can be improved. In order to provide this cushioning property, a material having a low elastic modulus or a material having rubber elasticity may be used. Specifically, natural rubber, acrylate rubber, butyl rubber, nitrile rubber, butadiene rubber, isoprene rubber, styrene-butadiene rubber, chloroprene rubber, urethane rubber, silicone rubber, acrylic rubber,
Elastomers such as fluorine rubber, neoprene rubber, chlorosulfonated polyethylene, epichlorohydrin, ethylene propylene diene rubber, urethane elastomer, polyethylene, polypropylene, polybutadiene, polybutene, impact-resistant ABS resin, polyurethane, ABS resin, acetate, cellulose acetate, amide resin,
Polytetrafluoroethylene, nitrocellulose, polystyrene, epoxy resin, phenol-formaldehyde resin, polyester, impact-resistant acrylic resin, styrene-butadiene copolymer, ethylene-vinyl acetate copolymer, acrylonitrile-butadiene copolymer, vinyl chloride -Among the vinyl acetate copolymers, polyvinyl acetate, vinyl chloride resin containing a plasticizer, vinylidene chloride resin, polyvinyl chloride, polyvinylidene chloride and the like, resins having a low elastic modulus are exemplified.

Examples of the shape memory resin usable as the cushion layer include polynorbornene and a styrene-based hybrid polymer in which a polybutadiene unit and a polystyrene unit are combined. Also,
These materials can be applied to the substrate to give the substrate itself cushioning properties. Although the thickness of the cushion layer varies depending on various factors such as the type of the resin or elastomer used, the heat transfer recording material and the suction force when the image receiving sheet is in close contact, and the use of the mat material, it cannot be unconditionally determined, but is usually 5 to 100 μm. Range. As a method of forming the cushion layer, a solution obtained by dissolving the above-described material in a solvent or dispersing it in a latex state, a blade coater, a roll coater,
Coating method of bar coater, curtain coater, gravure coater, etc., extrusion lamination method with hot melt,
A method of laminating a cushion layer film or the like can be applied.

(Release Layer) In the present invention, a release layer is formed between the photothermal conversion layer and the thermal transfer ink layer so that the thermal transfer ink layer can be peeled off from the photothermal conversion layer and easily transferred by laser light irradiation. it can. The release layer can be composed of wax alone, but is preferably composed of wax and / or a binder resin of a thermoplastic resin. Wax has a melting point or softening point of 50 ° C to 100 ° C
Natural waxes such as beeswax, spermaceti, wood wax, rice bran wax, carnauba wax, candelilla wax, montan wax; synthetic waxes such as paraffin wax, microcrystalline wax, oxidized wax, ozokerite, ceresin, ester wax, polyethylene wax; margarine Higher saturated fatty acids such as acids, lauric acid, myristic acid, palmitic acid, stearic acid, freunic acid and behenic acid; higher saturated monohydric alcohols such as stearyl alcohol and behenyl alcohol; higher esters such as fatty acid esters of sorbitan; And higher fatty acid amides such as oleic acid amide.

As the thermoplastic resin in the release layer, for example, an ethylene copolymer such as an ethylene-vinyl acetate resin, a polyamide resin, a polyester resin, a polyurethane resin, a polyolefin resin, an acrylic resin,
Cellulose resin, vinyl chloride resin, rosin resin,
Resins such as petroleum resins, ionomer resins, elastomers such as natural rubber, styrene-butadiene rubber, isoprene rubber, chloroprene rubber, ester gums, rosin maleic acid resins, rosin phenol resins, rosin derivatives such as hydrogenated rosins, phenol resins , Terpene resins, cyclopentadiene resins, aromatic resins and the like can also be used. The release layer can be peeled off at the interface with the thermal transfer ink layer so that the resin used in the release layer of the image receiving sheet described below and the resin cross-linked, the thermosetting resin having a Tg of 65 ° C. or higher and the cured product thereof Such a film can be formed of a resin alone film. Among them, those having a low affinity for the binder resin of the thermal transfer ink layer can have a low peeling adhesive force, and are excellent in sensitivity up.

The release layer is formed by the above wax,
Thermoplastic resins, other waxes such as higher fatty acids, higher alcohols, higher fatty acid esters, amides, higher amines, silicone oils, solid waxes such as polyethylene wax, fluorine-based or phosphate-based surfactants, etc. The coating liquid for forming a release layer to which the release agent is added is dried in a dry state by a conventionally known method such as hot melt coating, hot lacquer coating, gravure direct coating, gravure reverse coating, knife coating, air coating, or roll coating. The thickness is about 0.10 to 4 μm. When the thickness of the dried coating film is less than 0.10 μm, the adhesion between the light-to-heat conversion layer and the thermal transfer ink layer is improved, and a good peeling effect cannot be obtained. When the thickness exceeds 4 μm,
This is not preferable because the transfer sensitivity during printing decreases.

(Adhesive Layer) In the thermal transfer recording material of the present invention, an adhesive layer is formed on the thermal transfer ink layer to improve the adhesiveness between the image receiving sheet and the transferred ink layer.
The adhesive layer prevents blocking when the thermoplastic resin and / or the resulting thermal transfer recording material obtained by softening and exhibiting adhesiveness by heating by laser light irradiation means is rolled up or stacked in a sheet shape. For this purpose, it may contain an anti-blocking agent such as waxes, amides, esters and salts of higher fatty acids, powders of fluororesins and inorganic substances.

As the thermoplastic resin, for example, ethylene-
Vinyl acetate copolymer, ethylene-acrylate copolymer, polyester resin, polyethylene, polystyrene, polypropylene, polybutene, petroleum resin, vinyl chloride resin, vinyl chloride-vinyl acetate copolymer, vinylidene chloride resin, methacrylic resin, polyamide , Polycarbonate, polyvinyl formal, polyvinyl butyral, polyvinyl acetate, polyisobutylene, polyacetal, natural rubber, acrylate rubber, butyl rubber, nitrile rubber, butadiene rubber, isoprene rubber, styrene-butadiene rubber, chloroprene rubber, urethane rubber,
Elastomers such as silicone rubber, acrylic rubber, fluorine rubber, neoprene rubber, chlorosulfonated polyethylene, epichlorohydrin, ethylene-propylene-diene rubber, urethane elastomer, etc., and the like. Particularly, a relatively low softening point conventionally used as a heat-sensitive adhesive. For example, those having a softening point of 50 to 150 ° C are preferable.

The adhesive layer is formed by hot-melt coating of the above-mentioned materials and additives or a coating solution for forming an adhesive layer obtained by dissolving or dispersing in an appropriate organic solvent or water by a conventionally known hot-melt coating or hot-lacquer coating. , A gravure direct coat, a gravure reverse coat, a knife coat, an air coat, a roll coat, etc., to provide a thickness of 0.10 to 5 μm in a dry state. If the thickness of the dried coating film is less than 0.10 μm, the adhesiveness between the image receiving sheet and the thermal transfer ink layer is poor, resulting in poor transfer during printing. On the other hand, if the thickness exceeds 5 μm, the transfer sensitivity at the time of printing decreases, and satisfactory printing quality cannot be obtained.

(Back Layer) In the thermal transfer recording material of the present invention,
If necessary, provide a light-to-heat conversion layer and a thermal transfer ink layer on the substrate.
A back surface layer may be provided on the side opposite to the surface on which the light is applied. Back layer
Is used to improve the mechanical transportability of thermal transfer recording materials and to prevent curl.
As a lubricating layer, and for antistatic purposes, etc.
To be provided as a stop layer and an anti-blocking layer
Can be. Lubricious layer Opposite to the surface of the substrate on which the light-to-heat conversion layer and thermal transfer ink layer are provided.
On the other side, improve the transportability of the laser thermal transfer recording material,
A lubricating layer can be provided for preventing the occurrence of a drag. This
Acrylic resin etc.
Organic fillers such as fluorine resin and polyamide resin
Those added can be used. For example, acrylic
It is preferable to use a polyol or an organic filler. A
Kuryl polyols include ethylene glycol methacrylate
Acrylate, propylene glycol methacrylate
Which polymer is mentioned. In addition, ethylene glycol
Part is trimethylene glycol, butanediol,
Pentanediol, hexanediol, cyclopentanedi
All, cyclohexanediol, glycerin, etc.
Can also be used. These acrylic polyols are
In addition to contributing to the protection, additives such as organic and inorganic fillers are preserved.
It is easy to hold and has good adhesion to the substrate.

As the lubricating layer, an acrylic polyol cured with a curing agent can be used. As the curing agent, generally known curing agents can be used, and among them, isocyanate compounds are preferable. Acrylic polyol reacts with an isocyanate compound to form a urethane bond to be cured and three-dimensionally, thereby improving heat-resistant storage stability and solvent resistance, and further improving adhesion to a substrate. The amount of the curing agent to be added is preferably 1 to 2 with respect to one reactive group equivalent of the resin. Further, it is preferable to add an organic filler to the lubricating layer. By the action of the filler, the transportability of the thermal transfer recording material in a laser printer or the like is improved, and the storage stability of the thermal transfer recording material is also improved, such as by preventing blocking. Examples of the organic filler include an acrylic filler, a polyamide filler, a fluorine filler, and a polyethylene wax.

The lubricating layer is prepared by adding the above-mentioned resin and organic filler arbitrarily and kneading the mixture sufficiently with a solvent, a diluent or the like to produce a coating liquid, and applying the coating liquid to the other surface of the base sheet. In the same manner as the receiving layer forming means, a slip layer is formed by applying and drying by forming means such as a gravure printing method, a screen printing method, and a reverse roll coating method using a gravure plate. The thickness of the lubricating layer is 0.01 to 3.0.
It is about μm.

Antistatic Layer In order to prevent the laser thermal transfer recording material from being contaminated by dust and to ensure the stability of transportation by a printer, an antistatic layer containing the following antistatic agent can be provided on the back surface of the thermal transfer recording material. As the antistatic agent, any of conventionally known cations, anions, zwitterions and nonionics can be used. For example, quaternary ammonium salts,
Examples include cationic antistatic agents such as polyamine derivatives, anionic antistatic agents such as alkyl phosphates, and nonionic antistatic agents such as fatty acid esters. The antistatic layer may be added with the above antistatic agent and a lubricant such as an organic or inorganic filler, and a compounded solution obtained by dissolving or dispersing them in a solvent by a known method, that is, gravure coating, gravure reverse coating. It is formed by applying and drying by a method such as roll coating. The thickness of the antistatic layer is about 0.001 to 0.1 μm.

Anti- blocking layer The anti- blocking layer can be mainly composed of particles and a binder resin. As the particle material, inorganic particles such as silica, calcium carbonate, and clay, MMA, styrene,
Organic particles such as benzoguanamine are used. The particle size is
Usually, it is 1.0 to 50 μm, preferably 5 to 30 μm. The binder resin is preferably a thermoplastic resin having a Tg of 50 ° C. or higher. In particular, polyester resins, urethane resins, acrylic resins, and the like are preferable because they have high adhesiveness to the base material. The amount of the particles to be added is about 0.1 to 30 parts by weight, preferably 1 to 5 parts by weight, based on 100 parts by weight of the binder resin. If the number of particles is smaller than this, the effect of preventing blocking is reduced. On the other hand, if the number of particles is larger, transparency is reduced and heat conversion efficiency is reduced. The thickness of the anti-blocking layer is usually 0.2 to 20 μm, preferably 0.5 to 10 μm.

(Image-Receiving Sheet) The image-receiving sheet used in the present invention forms an image by receiving the thermal transfer ink layer peeled off from the above-mentioned thermal transfer recording material. Usually, an image receiving layer is provided on a base sheet, and the base sheet may be constituted by itself. The base sheet preferably retains the image receiving layer and has a mechanical strength that does not hinder handling even under heating conditions during thermal transfer by laser light irradiation. The material of such a base sheet is not particularly limited. For example, condenser paper, glassine paper, parchment paper, or high-size paper, synthetic paper (polyolefin-based, polystyrene-based), woodfree paper, art paper, coated paper , Cast coated paper, wallpaper, backing paper, synthetic resin or emulsion impregnated paper, synthetic rubber latex impregnated paper, synthetic resin internal paper, paperboard, etc., cellulose fiber paper, or polyester, polyacrylate, polycarbonate, polyurethane, polyimide, polyether Imide, cellulose derivative, polyethylene, ethylene-vinyl acetate copolymer, polypropylene, polystyrene, acrylic, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl butyral, nylon, polyether ketone, polysulfone, polyether Rusarufon, tetrafluoroethylene-perfluoroalkyl vinyl ether, polyvinyl fluoride, tetrafluoroethylene-ethylene, tetrafluoroethylene-hexafluoropropylene, polychlorotrifluoroethylene, films such as polyvinylidene fluoride and the like. The thickness of the above-mentioned substrate sheet may be arbitrary, and is usually about 10 to 300 μm.

Specific examples of the image receiving layer binder of the image receiving sheet include adhesives such as a polyvinyl acetate emulsion adhesive, a chloroprene adhesive, an epoxy resin adhesive, a natural rubber, a chloroprene rubber, a butyl rubber, and a polyacryl. Adhesives such as acid ester, nitrile rubber, polysulfide, silicon rubber, petroleum resin, recycled rubber, vinyl chloride resin, SBR, polybutadiene resin,
Polyisoprene, polyvinyl butyral resin, polyvinyl ether, ionomer resin, SIS, SEBS, acrylic resin, ethylene-vinyl chloride copolymer, ethylene-acryl copolymer, ethylene-vinyl acetate resin (EV
A), PVC-grafted EVA resin, EVA-grafted PVC resin, vinyl chloride resin, various modified olefins, polyvinyl butyral, polyester resin, styrene acrylic resin, urethane resin, etc., and have a relatively low softening point,
For example, those having a softening point of 50 to 150 ° C are preferable. In particular, those having a softening point in the range of 50 to 120 ° C. are preferable in that the image transferred to the image receiving sheet is retransferred to the transfer receiving body.

The image receiving layer preferably contains a mat material. As the mat material, inorganic particles such as silica, calcium carbonate, and clay, and organic particles such as MMA, styrene, and benzoguanamine are used. The particle size is usually 1.0 to 5
It is 0 μm and preferably 5 to 30 μm. The mat material is
It is preferable that the number average particle size is larger by about 1 to 6 μm than the average film thickness of the portion of the image receiving layer where the mat member does not exist. The image receiving layer is composed of a binder and a mat material, and various additives that are added as necessary.The forming method is a coating liquid for forming an image receiving layer dissolved or dispersed in an appropriate organic solvent or water,
Conventionally known methods such as gravure direct coating, gravure reverse coating, knife coating, air coating, and roll coating are used to provide a thickness of about 0.1 to 20 μm in a dry state.

When the image-receiving sheet on which an image has been formed is to be re-transferred to another object to be transferred, the base sheet may be made of a resin film, such as polypropylene or polyethylene terephthalate.
A resin film having excellent heat insulating properties is preferable, and it is also preferable to provide a release layer or a cushion layer between the base sheet and the image receiving layer. The release layer, as a binder, specifically polyester, polyvinyl acetal, polyvinyl formal, polyparabanic acid, polymethyl methacrylate,
Polycarbonate, ethylcellulose, nitrocellulose, methylcellulose, carboxymethylcellulose,
Hydroxypropyl cellulose, polyvinyl alcohol, polyvinyl butyral, polyvinyl pyrrolidone, vinyl acetate resin, polyvinyl chloride, polyvinyl chloride, polystyrene, acrylonitrile styrene, styrene such as styrene acrylic resin, and those resins crosslinked, polyamide, polyimide, Tg of polyetherimide, polysulfone, polyethersulfone, aramid, etc. is 65
Thermosetting resins having a temperature of not less than ℃ and cured products of those resins. As the curing agent, general curing agents such as isocyanate and melamine can be used.

Further, a layer having extremely low adhesion to the image receiving layer upon cooling after heating can be used as the release layer. Specifically, a layer mainly composed of a heat-fusible compound such as a wax or a binder or a thermoplastic resin can be used. Higher fatty acids, higher alcohols, higher fatty acid esters, amides,
Higher amines and the like can be added as needed. The formation of the release layer is the same as the method of forming the image receiving layer, and the thickness thereof is preferably 0.3 to 3.0 μm in a dry state. As the cushion layer used for the image receiving sheet, the same material, thickness and forming method as those of the cushion layer provided between the base material of the laser thermal transfer recording material and the light-to-heat conversion layer can be adopted. In the image receiving sheet, a back surface layer can be formed as necessary on the side opposite to the side on which the image receiving layer of the base sheet is provided.

(Recording Method) The recording method of the present invention comprises the above-described thermal transfer ink layer of the laser thermal transfer recording material,
The image is transferred onto the image receiving layer by bringing the image receiving layer into contact with the image receiving layer and irradiating the laser light. Further, it is possible to bring the thermal transfer ink layer of the laser thermal transfer recording material into contact with the image receiving layer of the image receiving sheet, transfer the image onto the image receiving layer by irradiating a laser beam, and then retransfer the image to the transfer receiving body. it can. The laser beam used in the recording method of the present invention is subjected to scanning exposure with a beam spot obtained by condensing a semiconductor laser beam oscillating near infrared light of 680 to 1100 nm to a diameter of 5 to 100 μm.

For example, as shown in FIGS. 1 and 2, the image receiving sheet 2 is held by suction through the suction holes 4 in a state of being in contact with the material holding means (drum) 5.
The laser heat transfer recording material 1 in which a light-to-heat conversion layer and a thermal transfer ink layer are laminated in this order on a substrate is passed through a pressure roll 3 so that the thermal transfer ink layer is brought into contact with the image receiving layer, and the material holding means 5 sucks the material. When the image receiving sheet 2 and the laser thermal transfer recording material 1 are in close contact with each other by suction from the holes 4, an image is formed by irradiating a laser beam as the optical writing means 6. Here, the laser beam as the optical writing means 6 is scanned in parallel with the axial direction of the drum. Further, as shown in FIG. 3, the image receiving sheet 2 is held by suction through the suction holes 4 in contact with the material holding means (flat plate) 7, and the image receiving layer of the image receiving sheet 2
A laser thermal transfer recording material 1 in which a light-to-heat conversion layer and a thermal transfer ink layer are laminated in this order on a base material is brought into contact with the thermal transfer ink layer. An image is formed by irradiating the laser thermal transfer recording material 1 with a laser beam as the optical writing means 6 in a state of being in close contact with the recording material. Here, the laser light as the optical writing means 6 is X, Y
The image is formed by scanning in the direction. The close contact by suction is preferably performed by bringing the image receiving sheet and the thermal transfer recording material into close contact with each other by a vacuum contact means because of excellent adhesion.

The energy to be applied can be changed by changing the amount of laser light or the irradiation area. The thermal transfer ink layer of the laser thermal transfer recording material and the image receiving layer of the image receiving sheet are brought into contact with each other to apply
When irradiating with a diameter of μm, an image may be formed by irradiating a laser beam from the thermal transfer recording material side, or an image may be formed by irradiating a laser beam from the image receiving sheet side.
For example, when forming an image by irradiating laser light from the thermal transfer recording material side, the laser light is irradiated from the substrate of the thermal transfer recording material to the photothermal conversion layer, but the substrate does not contain a laser light absorbing material Is preferred. When irradiating laser light from the image receiving sheet side to form an image,
The laser light is applied to the thermal transfer ink layer and the light-to-heat conversion layer of the thermal transfer recording material via the base sheet and the image receiving layer of the image receiving sheet, but the image receiving sheet and the thermal transfer ink layer do not contain a laser light absorbing material. Is preferred. This is because laser light irradiation effectively converts laser light into heat in the photothermal conversion layer. After transferring the image on the image receiving layer, the method of re-transferring the image to the transfer receiving body, the image receiving surface of the image receiving sheet on which the image is formed and the transfer receiving body are overlapped,
Pressing with a heat roller, heating with a thermal head, and irradiating infrared rays are mentioned.

[0041]

The present invention will be described more specifically with reference to examples and comparative examples. In the following description, parts are based on the weight of solid content. (Example 1) Polyethylene terephthalate (PET) film having a thickness of 100 µm (manufactured by Toray Industries, Inc., Lumirror T-
60), a coating liquid having the following composition is applied to one surface of the substrate by a reverse roll coater and dried to form a primer layer, a light-to-heat conversion layer, and a thermal transfer ink layer.
The layers were stacked in this order. Incidentally, the coating amount is 1.0 μm for the primer layer, 0.8 μm for the light-to-heat conversion layer and 0.6 μm for the thermal transfer ink layer when dried.

Primer layer coating liquid Polyester resin (Toyobo Co., Ltd., Byron 200) 10 parts Methyl ethyl ketone / toluene (1/1) 90 parts

Light heat conversion layer coating liquid carbon black 1 part Polyvinyl acetal resin 3 parts (manufactured by Sekisui Chemical Co., Ltd., Esrec, Tg: 110 ° C.) methyl ethyl ketone / toluene (1/1) 36 parts

Thermal transfer ink layer coating liquid Magenta pigment 3 parts Styrene-acrylic copolymer 6 parts (Hymer SBM-100: manufactured by Sanyo Chemical Co., Ltd.) Toluene 91 parts

A laser thermal transfer recording material of Example 1 was prepared by forming a back layer having the following composition on the other surface of the base material by roll coating to a coating amount of 1.0 μm when dried. . In addition, in the structure which provided the primer layer and the photothermal conversion layer on the said base material, the transmittance | permeability with respect to laser light with a wavelength of 780 nm was 70%. Back layer coating liquid acrylic resin (manufactured by Mitsubishi Rayon Co., Ltd., BR87) 20 parts Polymethyl methacrylate particles 0.4 part (manufactured by Sekisui Chemical Co., Ltd., MBX-20) Methyl ethyl ketone / toluene (weight ratio 1/1) 80 Department

(Example 2) The laser thermal transfer recording material of Example 2 was prepared in the same manner as in Example 1 except that the photothermal conversion layer was changed to the following composition in the laser thermal transfer recording material of Example 1. did. Light-to-heat conversion layer coating liquid carbon black 1 part Polyamideimide resin (Tg: 255 ° C.) 3 parts Methyl ethyl ketone / toluene (1/1) 36 parts A structure in which a primer layer and a light-to-heat conversion layer are provided on the above-described base material The transmittance for laser light having a wavelength of 780 nm was 70%.

(Comparative Example 1) A laser thermal transfer recording material of Comparative Example 1 was prepared in the same manner as in Example 1 except that the photothermal conversion layer of the laser thermal transfer recording material of Example 1 was changed to the following composition. did. Coating solution for light-to-heat conversion layer Carbon black 1 part Polyester resin 3 parts (manufactured by Toyobo Co., Ltd., Byron, Tg: 45 ° C) 36 parts of methyl ethyl ketone / toluene (1/1) 36 parts And a configuration in which a light-to-heat conversion layer was provided, and the transmittance for laser light having a wavelength of 780 nm was 70%.

Next, a release layer having the following composition was formed by gravure coating on a film having a microvoid inside the film having a thickness of 60 μm, and a coating amount of 1.5 μm was formed when dried. The image receiving layer was formed by gravure coating with a coating amount of 1.5 μm when dried to prepare an image receiving sheet. Release layer coating liquid hydroxypropyl methylcellulose 10 parts (Shin-Etsu Chemical Co., Ltd., Metroose) Water 60 parts Isopropyl alcohol 30 parts

Image receiving layer coating liquid Styrene acrylic resin (manufactured by Sanyo Chemical Co., Ltd., Hymer SBM-100) 10 parts Toluene 90 parts

With respect to the laser thermal transfer recording materials of the above Examples and Comparative Examples, heat resistance and transferability were examined under the following conditions. Heat resistance Each of the laser thermal transfer recording materials of the examples and comparative examples prepared above, and the above-described image receiving sheet, in a state where the thermal transfer ink layer of the laser thermal transfer recording material and the image receiving layer of the image receiving sheet are in contact with each other, As shown in FIG.
The image receiving sheet 2 and the laser thermal transfer recording material 1 were brought into vacuum contact with the suction flat plate 7 of the XY stage by suction from the suction holes 4 of, and the degree of destruction of the photothermal conversion layer when printed under the following conditions was visually examined. . Output: 100 mW Laser focusing diameter: 20 μm Applied pulse: 11.4 μsec

The heat resistance was evaluated according to the following criteria. ：: No destruction of the light-to-heat conversion layer occurs. C: Partial destruction of the light-to-heat conversion layer occurs.

Transferability Printing was performed in the same manner as the printing conditions for the heat resistance evaluation described above, and the transferability of the thermal transfer ink layer to the image receiving sheet was visually examined.
The evaluation was performed according to the following criteria. ：: dots having a diameter of 20 ± 5 μm are formed uniformly. X: Hardly transferred.

(Evaluation Results) The evaluation results are shown in Table 1 below.

[Table 1]

[0054]

As described above, the laser thermal transfer recording material of the present invention comprises at least a near-infrared absorbing material, a photothermal conversion layer mainly composed of a binder resin, and a thermal transfer ink layer laminated on a substrate in this order. By using the binder resin having a glass transition temperature of 100 ° C. or higher, a heat transfer recording material having high heat resistance of the light-to-heat conversion layer and not softening even at high output of laser light can be obtained. Furthermore, when carbon black, which is an inorganic particle material, is used as the near-infrared absorbing material, a suitable foil holding and high heat resistance can be achieved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing that a laser thermal transfer recording material of the present invention is superimposed on an image receiving sheet and wound around a drum of a material holding means.

FIG. 2 is an overall schematic configuration diagram showing a drum of a material holding unit and a periphery of the drum.

FIG. 3 is an overall schematic configuration diagram showing a flat plate and a periphery of the flat plate of the material holding means.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Laser thermal transfer recording material 2 Image receiving sheet 3 Pressure roll 4 Suction hole 5 Material holding means (drum) 6 Optical writing means 7 Material holding means (flat plate)

Claims (8)

[Claims] 1. A laser thermal transfer recording material in which at least a photothermal conversion layer and a thermal transfer ink layer mainly composed of a near-infrared absorbing material and a binder resin are laminated on a substrate in this order, the binder resin has a glass transition temperature of 100. A laser thermal transfer recording material having a temperature of at least ℃. 2. The laser thermal transfer recording material according to claim 1, wherein said near-infrared absorbing material is carbon black. 3. The laser thermal transfer recording material according to claim 1, wherein a primer layer is provided between the substrate and the photothermal conversion layer. 4. The laser thermal transfer recording material according to claim 1, wherein a cushion layer is provided between the substrate and the photothermal conversion layer. 5. The laser thermal transfer recording material according to claim 1, wherein a release layer is provided between the photothermal conversion layer and the thermal transfer ink layer. 6. The laser thermal transfer recording material according to claim 1, wherein an adhesive layer is provided on the thermal transfer ink layer. 7. A laser beam, wherein the thermal transfer ink layer of the laser thermal transfer recording material according to claim 1 is brought into contact with the image receiving layer of an image receiving sheet provided with an image receiving layer on a base sheet. A laser thermal transfer recording method, wherein an image is transferred onto the image receiving layer by irradiating the image. 8. The laser thermal transfer recording method according to claim 7, wherein after the image is transferred onto the image receiving layer, the image is re-transferred to an object to be transferred.