JP2002234267A - Thermal transfer recording sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal transfer recording sheet excellent in dyeing properties and moldability for making it into a card, without impairing the outward appearance of a substrate by heat drying on the occasion of applying a dye receiving layer. SOLUTION: The thermal transfer recording sheet has the sheetlike substrate containing a copolyester resin which contains a cyclohexanedimethanol in a poly-condensing glycol component and a cured resin layer formed by applying a coating composition containing a radiation-curable compound on one surface of the substrate at least and by subjecting it to radiation cure. The radiation- curable compound contains a urethane-unsaturated organooligomer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer recording sheet for a printer which can easily form a sheet, transfers dye or ink by heat, and can form a dyed image.

[0002]

2. Description of the Related Art In recent years, a thermal printer, particularly a thermal transfer printer capable of printing a clear full-color image, has attracted attention. A sublimation transfer printer uses a sublimation transfer dye sheet having a dye layer containing a dye that migrates by sublimation or melt diffusion by heat, and an image receiving sheet having a receptor layer for receiving the dye of the thermal transfer sheet on one surface of a film support. In this method, the dye layer and the receptor layer are superposed, and the dye at a predetermined portion of the dye layer is transferred onto the receptor layer by a predetermined concentration by heat supplied from a thermal head or the like to form an image. It has the feature that it is particularly advantageous for forming a photographic full-color image with high gradation.

A fusion heat transfer printer includes a transfer film (ink sheet) coated with ink that is melted by heat,
The ink receiving medium is pressed against a platen roll, heated from the back of the ink sheet to melt the ink (instantly), and transferred and recorded as an image. Since it is not heat diffusion, a sharp and high-density image with an effective edge can be obtained, and since a robust pigment type ink is used as the ink, the image has excellent light resistance and chemical resistance. This is particularly preferable for printing character information. Among cards represented by a magnetic card, an IC card, and the like, it is preferable that image information such as a photograph of a face be printed for an ID card such as a membership card or an employee card. As a method for forming an image having such photographic properties, the above-described sublimation transfer method is particularly excellent in terms of photographic gradation, operability of printing equipment, and high reliability. Therefore, for the above-mentioned applications, a face photograph or the like is printed in full color by a sublimation transfer method, and characters are printed clearly by a fusion heat transfer method. Sublimation and fusion heat transfer combined printers that enable this are already known, in which sublimable yellow, magenta, and cyan dyes are formed on a film,
And a surface coated with a dye-dyeable resin of a thermal transfer recording sheet is superimposed on a dye-coated surface of an ink sheet coated with a hot-melt transferable ink (especially, a black protective layer). With the heat supplied from the thermal head in response to the electric signals corresponding to the desired image and characters, dyes and inks are
An image is formed by transferring and dyeing a required density from a required location.

[0004] Cards currently mainly used in commercially available sublimation / fusion type card printers include cards molded and manufactured using polyvinyl chloride (hereinafter abbreviated as PVC) as a main resin, and laminating the surface with a PVC sheet. It is a polyethylene terephthalate (hereinafter abbreviated as PET) card. In recent years, there has been an increasing demand for non-chlorine-based cards due to the possibility of dioxins being generated due to the disposal and incineration of chlorine-containing resins. However, as a substitute for PVC cards, reports of non-chlorine-based resins with equivalent performance have been reported. There is no. For example, when a card molded from a sheet containing PET as a main resin is used, the dyeing property of the sublimation dye is poor, the transfer density of the molten heat transfer ink is low, and the softening point of the PET resin is high, so that molding and bonding are performed. It is difficult to process without using an adhesive (layer), and it is not possible to laminate or form a card by overlapping. For example, a magnetic stripe or a hologram can be formed on the back side using a direct thermocompression method which is a simple means. I can't even attach it. If it is necessary to attach the card, it is necessary to provide another layer that can be attached.However, if several cards are stacked, the layer structure of the card becomes asymmetric with respect to the center of the thickness and the contraction of each substrate Curling is likely to occur due to differences in ratio and orientation, and control is extremely difficult.

[0005]

As a result of investigations by the present inventors, a copolyester resin containing a 1,4-cyclohexanedimethanol structure in a glycol structure, particularly terephthalic acid, is suggested as an alternative to PVC having good moldability. When a sheet containing an acid-ethylene glycol-cyclohexane dimethanol copolymer as a main component is used, the moldability for carding is good, and the physical properties such as heat sealability and repeated bending are as close to PVC as possible. I knew I could do it. However, in our investigation, PVC
As in the case of the card, when sublimation / melt thermal transfer printing was performed directly on these copolyester resin films, the transfer density of the ink was low (Comparative Example 1 described later).

[0006] In addition, a method is known in which a dye-receiving layer having a dye-dyeing resin as a main component is provided on the surface of a sheet having a low dye-receiving property in order to impart dyeing properties. In order to obtain high-quality images, thermal transfer recording sheets having a dye-receiving layer having good dye-dyeing properties have been studied. As such dye-dyeing resins, various polyester resins and PVC resins have been proposed. Have been. For example, JP-A-57-107885
In Japanese Patent Application Laid-Open No. 61-3796, a saturated polyester resin is used.
Discloses a technique relating to a thermal transfer recording sheet using a sulfonated phthalic acid-modified polyester resin. JP-A-63-7971 discloses a thermal transfer recording sheet using a polyester resin comprising a polyol having a phenyl group and a dicarboxylic acid. Further, JP-A-59-223425, JP-A-63-51181
And JP-A-2-67194 propose a PVC resin.

However, according to the results of studies by the present inventors, this type of dye-dyeable resin or the like is usually dispersed and / or dissolved using a solvent such as toluene, alcohols, and water to form a base. The material sheet is applied and dried. However, since a large amount of paint is usually applied at a low solid content, it is necessary to rapidly dry at a high temperature in the drying step. For this reason, the substrate is required to have heat resistance, but the copolyester resin film containing the 1,4-cyclohexanedimethanol structure in the glycol structure that is easy to mold as described above has a low softening point and is inferior in heat resistance. The heat drying process impairs the appearance of the sheet and requires improvement.

Further, as a resin for the dye receiving layer, a technique using a radiation-curable resin or a radiation-curable organic compound which does not require a heat drying and heat curing step is disclosed. Japanese Patent Application Laid-Open Nos. 58-212994 and 62-2379 disclose such techniques.
0, JP-A-63-74691,
185746 and the like. However, none of them have sufficient dye-dyeing properties (Comparative Example 2 described later), and no thermal transfer printing of both sublimation and melting can be realized at a practical transfer density has been found so far. .

[0009]

According to the present invention, there is provided a dye-receiving layer which has excellent dye-dyeing properties without impairing the appearance of a support by heating and drying when coating the dye-receiving layer, and has a molding process for carding. A thermal transfer recording sheet having good properties is provided. The present invention can be easily processed without curling or the like after heat molding of a sheet, and can not only form a dyed image by diffusing and transferring a dye by heating, but also add an ink which softens and melts. Provided is a thermal transfer recording sheet capable of performing thermal transfer to clearly print characters and the like at a high density. The present invention is a sublimation heat transfer recording sheet useful for printing a full-color image excellent in transfer density and fusion resistance, and a heat transfer recording sheet capable of clearly transferring a high-density melt-heat transfer without a fusible ink. In particular, there is a need for cards such as a magnetic card utilizing magnetic properties used as an information recording medium and a card represented by an IC card having a built-in IC chip which is a large-capacity variable recording medium. This is a thermal transfer recording sheet capable of printing and printing both image and character information with high image quality. This thermal transfer recording sheet is characterized in that various processing as a card is easy.

[0010] The present invention includes the following embodiments. [1] A sheet-like support containing a copolyester resin containing cyclohexanedimethanol in a glycol component to be polycondensed, and a coating composition containing a radiation-curable compound is applied on at least one surface of the support and radiation-cured. A thermal transfer recording sheet having a formed cured resin layer, wherein the radiation-curable compound contains a urethane / unsaturated organo oligomer represented by the following general formula (1).

Embedded image (Wherein dehydrogenation residue of a polymer diol of -OR ¹ O-is the number average molecular weight 200 to 2000, -R ² - organic diisocyanate residue, -OR ³ O-is, dehydration of the hydroxyl groups of the dihydroxyl compound And CH ₂ ＣC (R
⁵ ) COOR ⁴ O— is a dehydrogenated residue of a hydroxyl group-containing (meth) acrylate ester having one or more double bonds, R ⁵ is a hydrogen atom or a methyl group, and R ⁴ is a dihydric alcohol residue. Groups are shown below. N represents an integer of 1 to 100. )

[2] In the sheet-like support, the elongation onset temperature (hereinafter, also referred to as “softening point”) obtained from a temperature rise test using a thermomechanical property tester (hereinafter, also referred to as “TMA”) is 50 ° C. Not less than 140 ° C. [1]
The thermal transfer recording sheet according to the above. [3] The thermal transfer recording sheet according to [1] or [2], wherein the copolyester resin contains 5 mol% or more of 1,4-cyclohexanedimethanol in 100 mol% of a glycol component.

[4] The thermal transfer recording sheet according to [1], wherein the copolyester resin is obtained by polycondensing a monomer containing terephthalic acid, ethylene glycol and 1,4-cyclohexanedimethanol. [5] The thermal transfer recording sheet according to any one of [1] to [4], which contains 10% by weight or more of the urethane / unsaturated organo oligomer based on 100% by weight of the total weight of the curable resin layer.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION One kind of radiation-curable compound used in the present invention is a urethane / unsaturated organo oligomer represented by the general formula (1). Further, the sheet-like support used in the present invention is composed mainly of a copolyester resin containing a 1,4-cyclohexanedimethanol structure in a glycol structure, preferably at least 5 mol%. -OR ¹ O-dehydrogenation residue of a polymer diol having a number average molecular weight of 200 to 2000 of the general formula (1) used in the present invention, -R ² - is an organic diisocyanate residue, -OR ³ O-
Is a dehydrogenation residue of a hydroxyl group of a dihydroxyl compound; CH ₂ ＣC (R ⁵ ) COOR ⁴ O— is a dehydrogenation residue of a hydroxyl group-containing (meth) acrylate ester having one or more double bonds. , N represents an integer of 1 to 100.

There is no particular limitation on the polymer diol that is the raw material of —OR ¹ O—. For example, at least one polyether diol selected from polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like, at least one polyester diol selected from esters of polyhydric alcohol and polybasic acid, hexamethylene carbonate, and At least one kind of polycarbonate diol selected from pentamethylene carbonate and at least one kind of polylactone diol selected from polycaprolactone diol and polybutyrolactone diol are preferable. These polyether diols, polyester diols,
Examples thereof include polycarbonate diols and polylactone diols. One of them can be selected or a plurality of them can be combined.

[0015] Of these, the use of a polymer diol having an aromatic ring introduced therein is particularly effective because high dye-dyeing properties can be imparted. As one of the polymer diols having an aromatic ring structure, a polyester diol comprising an ester of a polyhydric alcohol and a polybasic acid can be exemplified. The aromatic ring structure has only to be introduced into at least one of the polyhydric alcohol and the polybasic acid which are the raw materials of the polyester diol, and both may be introduced. In particular, when an aromatic ring structure is introduced into a polybasic acid, it is more effective, and specific examples include terephthalic acid, isophthalic acid, and naphthoic acid. Further, as another polymer diol having an aromatic ring structure, bisphenol A
Type diols. The number average molecular weight of the polymer diol is from 200 to 2,000, more preferably from 300 to 1500.

The organic diisocyanate compound used as a raw material for --R ^2- is 2,4-tolylene diisocyanate,
6-tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, xylylene diisocyanate,
Isophorone diisocyanate, methylene bis (4-cyclohexyl isocyanate), tetramethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexane
One or more selected from 1,3-dimethylene diisocyanate, cyclohexane-1,4-dimethylene diisocyanate, norbornane diisocyanate, 1,5-naphthalenediisocyanate and the like can be combined.

The dihydroxyl compound is -OR ³ O-raw material is preferably at least one selected from glycol having 2 to 10 carbon atoms. Accordingly, the general formula (1) in the -R ³ - means a hydrocarbon having 2 to 10 carbon atoms. More preferably, it has 2 to 6 carbon atoms.
Ethylene glycol, 1,3-propanediol, 1,
4-butanediol, neopentyl glycol, 1,5
-Pentanediol, methylpentanediol, 1,6
-Hexanediol, 3-methyl-1,5-pentanediol and the like.

-(OR ¹ OOCNHR ² NHCOOR ³ O
[OCNHR ² NHCO) _n -The number in parentheses is a repeating unit in the urethane / unsaturated organo oligomer, and n is an integer of 1 to 100, preferably 1 to 20, and more preferably 1 to 10. (Meth) acrylic acid ester structure containing at least one double bond constituting both ends of urethane / unsaturated organo oligomer CH ₂ ＝ C
The raw material of (R ⁵ ) COOR ⁴ O— is a hydroxy group-containing (meth) acrylate, specifically, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy -3-phenoxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, a caprolactone or alkylene oxide adduct of each of the above acrylates, glycerin mono (meth) acrylate, glycerin di (meth) acrylate, glycidyl methacrylate-acrylic acid adduct, Trimethylolpropane mono (meth) acrylate, trimethylol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, ditrimethylolpropane tri ( Data) acrylate, trimethylolpropane - alkylene oxide adducts - can at least one is applicable are selected from di (meth) acrylate. R ⁵
-Means a methyl group or a hydrogen atom.

The urethane / non-urethane represented by the general formula (1)
To obtain a saturated organo oligomer, first, a number average molecular
A polymer diol in an amount of 200 to 2000
Silyl group compound and organic isocyanate compound
An addition reaction is performed to obtain a polymer having isocyanate groups at both ends.
A ethane oligomer is obtained. Next, this terminal isocyanate
(Meth) acrylic acid containing hydroxyl group in nate group
It is synthesized by addition condensation of ter. like this
Urethane / unsaturated organo oligomer obtained by
Is one or more types of radiation selected from electron beams and ultraviolet rays
Double bonds forming both ends by irradiation
(Meth) acrylate structure containing at least one
H₂= C (R ⁵) COOR⁴O- is polymerized and is related to the present invention.
Forming a radiation-curable resin coating layer for the purpose.

When curing and polymerizing by irradiation with ultraviolet light,
It is preferable to use a compound called a photoreaction initiator that generates a radical species, a cation species, an anion species and the like by light irradiation. As described above, the use of the radiation-curable compound according to the present invention eliminates the need for heating when the resin is dried and / or cured, so that the sheet-shaped support is not thermally deformed and further has an external shape. There is no loss.

Next, the general formula (1) in the coating composition
The other components will be described. The coating composition may contain other components for controlling dye-dyeing properties, friction properties, whiteness, coating fluidity, curing speed, and the like. However, the content of the substance represented by the general formula (1) is preferably 10% by weight or more, more preferably 20% by weight or more, based on the weight of the cured resin coating layer. Here, the weight of the cured resin layer means the weight after drying of water / solvent and / or the completion of the curing reaction and removal of volatile components.

The other components include a radiation curable compound, an organic solvent, a pigment and the like. Furthermore, antioxidants, antistatic agents, stabilizers, lubricants such as silicone oil or friction coefficient reducing agents, furthermore,
Various additives such as a light resistance improver can be appropriately added. Examples of the organic solvent used for lowering the viscosity of the paint and facilitating the coating include 2-butanone, acetone, and toluene. A high temperature and a long time are required, which may cause thermal deformation of the sheet-like support.

In order to lower the viscosity of the paint and / or control the curability, a radiation-curable organic compound can be further used. As the radiation-curable organic compound, monomers, oligomers and polymers conventionally known for radiation-curable thermal transfer recording receptors can be used.

Specific examples thereof include, as monofunctional compounds, methyl acrylate, ethyl acrylate, lauryl acrylate, stearyl acrylate, N-vinylpyrrolidone, acryloylmorpholine, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, and 2-hydroxyethyl acrylate. Ethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate,
2-hydroxybutyl methacrylate, tetrahydrofurfuryl acrylate, tetrahydrofurfuryl methacrylate, caprolactone-modified tetrahydrofurfuryl acrylate, cyclohexyl acrylate, cyclohexyl methacrylate, dicyclohexyl acrylate, isobornyl acrylate, isobornyl methacrylate, benzyl acrylate, benzyl methacrylate, ethoxydiethylene glycol Acrylate, methoxytriethylene glycol acrylate, methoxypropylene glycol acrylate, phenoxy polyethylene glycol acrylate, phenoxy polypropylene glycol acrylate, nonylphenoxy polyethylene glycol acrylate, ethylene oxide-modified phenoxy acrylate Nonylphenoxy polypropylene glycol acrylate, N, N-dimethylaminoethyl acrylate, N, N-dimethylaminoethyl methacrylate, 2-ethylhexyl carbitol acrylate, ω-carboxypolycaprolactone monoacrylate, monohydroxyethyl phthalate, acrylic acid dimer , 2-hydroxy-3-phenoxypropyl acrylate, 9,10-epoxidized oleyl acrylate, 9,10-epoxidized oleyl methacrylate, ethylene glycol monoacrylate maleate, dicyclopentenyl acrylate, dicyclopentanyl acrylate , Dicyclopentenyloxyethylene acrylate, acrylate of caprolactone adduct of 4,4-dimethyl-1,3-dioxolane And acrylates of caprolactone adducts of 3-methyl-5,5-dimethyl-1,3-dioxolane, polybutadiene acrylates, and ethylene oxide-modified phenoxylated phosphoric acid acrylates.

Also, ethanediol diacrylate, ethanediol dimethacrylate,
1,3-propanediol diacrylate, 1,3-propanediol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate,
1,6-hexanediol dimethacrylate, 1,9-
Nonanediol diacrylate, 1,9-nonanediol dimethacrylate, 1,14-tetradecanediol diacrylate, 1,15-pentadecanediol diacrylate, diethylene glycol diacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, polypropylene glycol diacrylate , Polypropylene glycol dimethacrylate, neopentyl glycol diacrylate, 2-
Butyl-2-ethylpropanediol diacrylate,
Ethylene oxide modified bisphenol A diacrylate, polyethylene oxide modified bisphenol A diacrylate, polyethylene oxide modified hydrogenated bisphenol A diacrylate, propyl oxide modified bisphenol A diacrylate, polypropylene oxide modified bisphenol A diacrylate, hydroxypivalic acid ester neopentyl glycol ester diacrylate Acrylate, hydroxypivalic acid ester neopentyl glycol ester caprolactone adduct diacrylate,
Ethylene oxide-modified isocyanuric acid diacrylate,
Pentaerythritol diacrylate monostearate, 1,6-hexanediol diglycidyl ether acrylic acid adduct, polyoxyethylene epichlorohydrin-modified bisphenol A diacrylate, tricyclodecane dimethanol diacrylate, trimethylolpropane triacrylate, ethylene oxide Modified trimethylolpropane triacrylate, polyethylene oxide-modified trimethylolpropane triacrylate, propylene oxide-modified trimethylolpropane triacrylate, polypropylene oxide-modified trimethylolpropane triacrylate, pentaerythritol triacrylate, ethylene oxide-modified isocyanuric acid triacrylate, ethylene oxide-modified glycerol triacrylate Acrylate, poly Tylene oxide-modified glycerol triacrylate, propylene oxide-modified glycerol triacrylate, polypropylene oxide-modified glycerol triacrylate, pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, Examples include caprolactone-modified dipentaerythritol hexaacrylate and polycaprolactone-modified dipentaerythritol hexaacrylate. However, it is not limited to these.

Of these, the use of the following radiation-curable compounds makes it possible to lower the viscosity of the coating without reducing the effect of the substance of the general formula (1). Ethylene glycol diacrylate,
1,2-propanediol diacrylate, 1,3-propanediol diacrylate, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, neopentyl glycol diacrylate, 1,5
-Pentanediol diacrylate, methylpentanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate,
2-ethyl, 2-butyl-propanediol diacrylate and the like.

When a pigment is incorporated into the coating composition, the pigment is added in an amount of 8 parts by weight based on 100 parts by weight of the total cured resin layer after drying.
It is preferably 0 parts by weight or less. More preferably 6
0 parts by weight or less. When the amount exceeds 80 parts by weight, not only does the effect of the present invention decrease, but also the viscosity of the resin coating before curing becomes excessively high, which may result in poor fluidity. Examples of the pigment include clay, kaolin, talc, silica, magnesium hydroxide, aluminum hydroxide, heavy calcium carbonate, light calcium carbonate, titanium dioxide (anatase type and rutile type), zinc white, and barium sulfate. Organic pigments such as polystyrene, known as plastic pigments, can be used. These pigments are usually white,
The surface may be used without any treatment, but may be used after surface treatment with siloxane, alumina, alcohol, silane coupling agent or the like. The pigment may be composed of a single type, or may be used as a mixture of two or more types. Further, the radiation curable resin composition containing such a pigment is a dispersant, a release agent, an antifoaming agent, a coloring agent,
Known auxiliaries, such as dyes and preservatives, may be added as necessary.

To disperse the white pigment in the composition containing the radiation-curable compound, a three-roll mill (three-roll mill), a two-roll mill (two-roll mill), a Cowles dissolver, a homomixer, a sand grinder, A planetary mixer, an ultrasonic disperser, or the like can be used. As a method for producing the thermal transfer recording sheet according to the present invention, a radiation curable compound composition may be applied on the surface of a sheet-like support to form a coating liquid layer, and then cured by irradiation with radiation. When the coating liquid contains an organic solvent such as toluene, acetone, or 2-butanone, a drying step may be preferably provided before the radiation curing step.
The drying device used is not particularly limited, and an electric or gas infrared dryer using radiant heat, a roll heater using electromagnetic induction, an oil heater using an oil medium, and a drying device using these hot airs And the like.

Furthermore, in order to impart gloss, a casting method can be used. As a casting method, (1) a radiation-curable compound composition is applied on the surface of a sheet-like support to form a coating liquid layer, and the radiation is applied in a state where the coating liquid layer is brought into contact with the surface of the molded substrate. A method of peeling the molded substrate after curing, (2) a state in which a radiation curable compound composition is applied to the surface of the molded substrate to form a coating liquid layer, and a sheet-like support is stuck to the coating liquid layer And a method of separating the sheet containing the cured resin layer from the surface of the molded substrate, and the like, or any of these methods or other methods. PET film,
A metal drum having a smooth surface such as a metal drum having a mirror surface can be exemplified.

Examples of the method of applying the radiation-curable compound composition to a support include a bar coating method, an air doctor coating method, a blade coating method, a squeeze coating method, an air knife coating method, a roll coating method, and a gravure coating method. , Transfer coating method, comma coating method, smoothing coating method, microgravure coating method, reverse roll coating method, multi-roll coating method, dip coating method, rod coating method, kiss coating method, gate roll coating method, falling curtain coating method, Slide coating method,
A fountain coating method, a slit die coating method, or the like can be used. In particular, when a metal cylindrical rotating body is used as a molding base by a casting method, a roll coating method using a coating rubber roll or an offset gravure coating is used to prevent the surface of the metal cylindrical rotating body from being damaged. It is preferable to use a non-contact type fountain coater, a slit die coater or the like.

As the molding substrate used in the casting method, a metal cylindrical rotating body can be used, but the material and shape are not limited. For example, stainless steel, copper,
What is formed from chrome or the like and has a mirror-finished smooth peripheral surface is used. Further, in order to facilitate the separation between the cured resin coating layer and the surface of the substrate, a release aid such as silicone oil or wax can be supplied to the surface of the metal cylindrical rotary member.

The sheet-like material for molding used as the molding substrate is not particularly limited as long as it is smooth and flexible.
Specifically, a plastic film such as a polyester film, a metal sheet, a resin-coated paper, a metal-deposited film, a metal-deposited paper, or the like is preferable. On the surface of the sheet material for molding, the cured resin coating layer is easily peeled off. For this purpose, a release aid such as silicone or wax may be supplied. Further, the surface of the sheet-shaped material may be subjected to an appropriate treatment in advance, for example, a treatment such as a silicone treatment, to facilitate the peeling of the cured resin coating layer. The sheet-like material used as the molding base may be processed into an endless belt shape. The sheet-like material used as the molding base can be used repeatedly, but the repeated irradiation will deteriorate the sheet-like material, and thus the number of times of repeated use is limited.

The sheet-like support used in a preferred embodiment is a non-PVC-based copolyester resin containing cyclohexanedimethanol, preferably 1,4-cyclohexanedimethanol in 100 mol% of a glycol component, preferably 5 mol% or more. A resin film (or sheet) having a softening point of preferably 50 to 140 ° C. Glycol structure 1
The content of cyclohexanedimethanol in 00 mol% is preferably 5 mol% or more, more preferably 5 to 70 mol%.
And more preferably 10 to 60 mol%, and most preferably 25 to 55 mol%. Examples of the glycol component include ethylene glycol and cyclohexane dimethanol. Such a resin is obtained by polycondensation of terephthalic acid and a glycol component, but can also be obtained by polycondensing terephthalic acid with a terephthalic acid ester such as dimethyl terephthalate or its chloride and a glycol component. Can be done. For the polycondensation, a known method is employed.

In the present invention, the softening point is defined as a thermomechanical property tester TMA / SS6 manufactured by Seiko Instruments Inc.
100 was measured in the load control mode (assembly F control mode). That is, the displacement of the resin film was measured under the measurement conditions of a load of 100 g and a temperature rising rate of 5 ° C./min, and the straight line portion of the displacement-temperature curve, which was observed on the lower temperature side than the resin film began to soften, was extended on the higher temperature side. The intersection of the tangent of the portion where the displacement is maximum and the extension line to the low temperature side is defined as the softening point (4 mm width, 100 μm thickness).
temperature range with the distance between chucks being 1 cm for a sample of m
The displacement of the sample was measured at 20-200 ° C. ). In particular, P
Glycol-modified copolyester resin in which part of the ethylene glycol structure in ET has been replaced with 1,4-cyclohexanedimethanol structure must have heat-sealability and physical properties close to PVC without limit depending on the copolymerization ratio. Can be
As a PVC substitute material, there is an advantage that a card processing machine used for PVC can be used as it is.

The softening point of the copolyester resin film support used in the present invention is preferably in the range of 50 to 140 ° C. From the viewpoint of heat resistance, more preferably,
60-120 ° C. When the temperature is lower than 50 ° C., the moldability is good, but the heat resistance is poor and the film may be elongated, and the mechanical properties are also poor, which is not preferable. On the other hand, if the temperature is higher than 140 ° C., heat resistance and mechanical properties are excellent, but the molding processability is lacking, and there is a difficulty in carding, which is not practically preferable. If the softening point is within the range of the present invention, it is practically preferable because heat resistance sufficient to withstand heating and drying of the solvent contained in the coating resin liquid can be maintained while maintaining suitability for molding.

The softening point may be adjusted by one or more of a copolyester resin copolymerization ratio, a plasticizer, and / or mixing with another resin, a stretching ratio, and the like, as long as the effects of the present invention are not lost. It can be controlled by known factors. When a plurality of resins are used, resins having good miscibility with generally known polyester resins such as other polyester resins and polycarbonate resins are preferable. Among them, the bisphenol A type polycarbonate resin has very good miscibility with the polyester resin, and not only can easily adjust the softening point, but also can effectively impart heat resistance and improve mechanical properties. Therefore, it is particularly preferable. In order to facilitate the mixing of the resin, known additives such as a compatibilizer may be used as long as the effects of the present invention are not lost. In the resin of the support, the specific copolyester resin is 5 to 100% by weight, preferably 10 to 90% by weight,
Most preferably, the content is 15 to 80% by weight.

The support resin film according to the present invention has good moldability, does not contain chlorine, emits no harmful exhaust gas during combustion, has excellent heat-sealing properties, and has high adhesion as compared with PVC. High strength and high performance in durability such as repeated bending. A support having the above-mentioned performance is provided by I
When used as a card base material of a C card or the like, it has a feature that a magnetic stripe, a hologram, a sign panel, and the like can be thermocompression-bonded without curling in a bonding step. In the thermal transfer recording sheet of the present invention, the coating amount of the radiation-curable resin layer is 1 to after curing.
It is preferably 60 g / m ² , more preferably ² g / m 2.
４０40 g / m ² . If the coating amount is less than 1 g / m ² , the resulting coated body will have insufficient smoothness, fail to provide aesthetics, and may have reduced gloss. If it exceeds 60 g / m ² , the effect may be saturated and the cost may increase. Further, the transfer density of the sublimable dye may decrease, which is not preferable.

For the purpose of averaging the unevenness of the support of the present invention and improving the whiteness and opacity, a precoat layer may be used, and the same purpose and / or the smoothness of the surface is further enhanced. For the purpose, two layers of radiation-cured resin
A stacked structure of more than two layers may be used. As a material constituting the precoat layer, an inorganic coat layer such as clay, talc, kaolin, ansilex, and polyethylene (high-density polyethylene, low-density polyethylene, medium-density polyethylene,
Linear low-density polyethylene), thermoplastic resin homopolymers such as polypropylene, polybutene, polypentene or copolymers of two or more olefins such as ethylene / propylene copolymers, (meth) acrylic resins, vinyl resins Organic materials such as cellulose resins, urethane resins, polyester resins, and copolymer resins thereof can be used, and these resins can be used alone or in combination. These resins may contain a white pigment for improving whiteness and opacity. Further, hollow particles may be contained for the purpose of improving the adhesion to the ink sheet and the heat insulating property of the image receiving layer. These inorganic and / or organic materials are applied by being dissolved or dispersed in a solvent-based or aqueous medium.

In the present invention, the surface of the support may be subjected to a surface treatment such as corona treatment or sub-coating in order to improve the adhesiveness and wettability between the support and the radiation-curable resin coating layer. On the back surface of the thermal transfer recording sheet of the present invention, a resin coating layer is formed by a method of applying a polyolefin resin by a melt extrusion method, or by applying a radiation-curable compound coating solution to form a film by irradiation with radiation, A back coat layer can be provided for preventing curling, preventing static charge, and providing writability. An antistatic agent for the back coat layer,
A hydrophilic binder, a latex, a hardener, a pigment, a surfactant and the like can be appropriately combined and contained.

The radiation for curing the radiation-curable compound coating liquid according to the present invention may be, for example, at least one high-energy ray selected from electron beams, ultraviolet rays and the like. As the electron beam irradiation device used for electron beam irradiation,
Although there is no particular limitation on the method, for example, an electron beam irradiation apparatus such as a handicraft scanning method, a double scanning method, a broad beam method, and a curtain beam method can be used. Among them, the curtain beam method, which is relatively inexpensive and provides a large output, is effectively used in the present invention. The acceleration voltage during electron beam irradiation is
It is preferably 100 to 1000 kV from the viewpoint of curing power, and more preferably, an electron beam accelerator of 100 to 300 kV is used, and the absorbed dose in one pass is preferably 0.1 to 20 Mrad. Furthermore, 0.5 to 10 Mrad
Is particularly preferred. If the accelerating voltage or the amount of electron beam irradiation is lower than this range, the penetrating power of the electron beam is too low to sufficiently cure the inside of the support, and if it is higher than this range, not only does energy efficiency deteriorate. In addition, unfavorable effects on quality such as a decrease in strength of the support and decomposition of the resin and additives may occur. In electron beam irradiation, when the oxygen concentration is high, the curing of the electron beam-curable compound is hindered. Therefore, replacement with an inert gas such as nitrogen, helium, or carbon dioxide is performed to reduce the oxygen concentration to 1000 ppm or less, preferably 500 ppm or less. Irradiation is preferably performed in an atmosphere in which the temperature is suppressed.

In the case of ultraviolet rays, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, or the like can be used as an ultraviolet irradiation device. Further, an ozone-less type that generates less ozone may be used. It is desirable to use a lamp having an energy of 80 W / cm or more for the irradiation. In addition, a photoreaction initiator can be used in the radiation curable compound coating liquid. Examples of the photoinitiator include acetophenones such as di- and trichloroacetophenone, benzophenone, Michler's ketone, benzyl, benzoin, benzoin alkyl ether, benzyldimethyl ketal, tetramethylthiuram monosulfide, thioxanthones, and azo compounds.

[0042]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. Example 1 A thermal transfer recording sheet was prepared by the following operation and evaluated. Composition (1) Ingredient 80 % by weight of urethane / unsaturated organo oligomer (trademark: UF502LN, manufactured by Kyoeisha Chemical Co., Ltd., with the substituents and n shown in Table 1), neopentyl glycol diacrylate (manufactured by Kyoeisha Chemical Co., Ltd.) 20 parts by weight, 0.3 parts by weight of silicone oil (Shin-Etsu Chemical Co., Ltd.).

In the composition (1), the urethane / unsaturated organo oligomer according to the present invention is described in Table 1.
This was synthesized according to the method described in JP-A-11-35657. That is, a hydroxyl group-containing (meth) acrylic acid ester was addition-polymerized to a urethane oligomer having isocyanate groups at both terminals obtained by polyaddition reaction of a polymer polyol, a dihydroxyl compound, and an organic diisocyanate compound. Preparation of Thermal Transfer Recording Sheet The above composition (1) was used as a sheet-like support in a thickness of 100
μm white PETG copolyester film (trademark:
Table 2 shows the glycol components of the base film of Trepaloy GW, manufactured by Toray Synthetic Film Co., Ltd. ), A coating liquid was coated on a wire bar of # 10 such that the coating amount after drying and curing was 10 g / m ^2, and dried at 80 ° C. for 30 seconds. The accelerating voltage is 175k from the coated surface.
The composition (1) was cured by irradiating an electron beam under the conditions of V, an absorbed dose of 7 Mrad, and an oxygen concentration of 500 ppm or less to obtain a thermal transfer recording sheet of the present invention.

Test and Evaluation Method (1) Softening Point The softening point of the sheet-shaped support was measured in a load control mode (assembly F control mode) using a thermomechanical property tester (TMA / SS6100, manufactured by Seiko Instruments Inc.). did. That is, the displacement of a resin film sample at a load of 100 g and a temperature rise rate of 5 ° C./min was measured, and a straight line portion observed at a lower temperature side than the film began to soften / elongate in a displacement-temperature curve was extended to a higher temperature side. Then, the intersection of the tangent line of the portion where the displacement becomes maximum and the extension line to the low temperature side was defined as the softening point. The sample width was 4 mm, the thickness was 100 μm, the distance between the chucks was 1 cm, and the measurement temperature range was −20 to 200 ° C. The evaluation results are shown in Tables 2 and 3. (2) Evaluation of Dye Transfer Density As for the dye transfer density, black density step printing was performed using a commercially available color video printer for cards (manufactured by Nozaki Printing Co., Ltd.).
The maximum dyeing concentration was evaluated using a Macbeth densitometer (RD-914, manufactured by Sakata Inx, using an A filter). Table 3 shows the evaluation results. The transfer density is preferably higher than 1.6, and if it is lower, it is judged to be impractical.

(3) Evaluation of Deformation of Thermal Transfer Recording Sheet The state of deformation, wrinkles and warpage of the produced thermal transfer recording sheet was visually determined. ：: Level determined to have no deformation, wrinkles or warpage at all. ：: A level at which slight deformation, wrinkles, and warpage are observed, but are judged to be practically acceptable. C: Deterioration, wrinkles, and warpage were severe, and the results of levels determined to be unsuitable for practical use are shown in Table 3.

(4) Evaluation of Suitability for Forming A hot-melt adhesive was sandwiched between the produced thermal transfer recording sheet and the same kind of sheet-like support used for the same, and was heated at 125 ° C. and 5 kg with a hot press. Both sheets were pressed together at a pressure of / cm ² . Thereafter, a card capable of full-color printing was obtained by a card punching machine. The adhesiveness of the card and the ease of punching were determined. ◎: A level at which no warpage cracks occur in the card when punched, and no peeling of the adhesive occurs. ×: Two sheets are easily peeled off and / or
When punched out, warping and cracking occur, making it unpractical. Table 3 shows the evaluation results.

Example 2 The same operation as in Example 1 was performed. However, the following composition (2) was prepared in place of the composition (1), and a 100-μm-thick white polyester alloy film (trade name: Trepalloy HW; Toray Synthetic Film Co., Ltd., glycol component of polyester resin in the base film,
Table 2 shows the resins to be mixed with the polyester resin. )
It was used. Composition (2) Component Compounding amount 35 parts by weight of urethane / unsaturated organo oligomer (trade name: UF503BPE, manufactured by Kyoeisha Chemical Co., Ltd.) 15 parts by weight of neopentyl glycol diacrylate (Kyoeisha Chemical Co., Ltd.), 50 parts by weight of 2-butanone 0.3 parts by weight of silicone oil (Shin-Etsu Chemical Co., Ltd.). The urethane / unsaturated organo oligomer according to the present invention in the composition (2) is described in Table 1. This was synthesized according to the method described in JP-A-11-35657. Table 3 shows the evaluation results.

Example 3 A thermal transfer recording sheet was produced by the following operation. However,
The following composition (3) was prepared and used in place of composition (1). Composition (3) Component Compounding amount 20 parts by weight of urethane / unsaturated organo oligomer (trade name: UF503BPE, manufactured by Kyoeisha Chemical Co., Ltd.), 80 parts by weight of imide-modified acrylate monomer (trade name: ZP-90, manufactured by Zeon Corporation) The urethane / unsaturated organo oligomer according to the present invention in the composition (3) is described in Table 1. This was synthesized according to the method described in JP-A-11-35657. Preparation of Thermal Transfer Recording Sheet The composition (3) was used as a sheet-like support in a thickness of 100
Using a μm white PETG copolyester film (trademark: Diaflex PG-WHI, manufactured by Mitsubishi Plastics, Ltd., details of the glycol component of the base film are described in Table 2), a coating solution is coated on one side with # 10 wire bars were coated so that the coating amount after drying and curing was 10 g / m ² . A 75 μm silicone-coated polyester film (trade name: SP-PET-O) to be used as a molding substrate thereon
5-75B, manufactured by Tocelo Co., Ltd.), an acceleration voltage of 175 kV, an absorbed dose of 7 Mrad, an oxygen concentration of 50
The composition (3) is irradiated with an electron beam under the condition of 0 ppm or less.
Was cured. Thereafter, the silicone-coated polyester film was peeled off from the resin coating layer, and a thermal transfer recording sheet of the present invention having a radiation-cured resin coating layer was obtained and evaluated. Table 3 shows the evaluation results.

Comparative Example 1 As a thermal transfer recording sheet, a white PETG copolyester film (trade name: Trepaloy GW, manufactured by Toray Synthetic Film Co., Ltd., details of the base film are described in Table 2) was used and evaluated. Table 3 shows the evaluation results.

Comparative Example 2 According to the example described in JP-A-5-185746,
The following composition (4) was prepared in place of the composition (1),
A thermal transfer recording sheet was prepared in the same manner as in Example 3, and evaluated in the same manner as in Example 1. Composition (4) Component Incorporation amount 60 parts by weight of isobornyl acrylate (manufactured by Kyoeisha Chemical Co., Ltd.) and 40 parts by weight of trimethylolpropane triacrylate (manufactured by Toa Gosei Chemical Industry Co., Ltd.) Table 2 shows the evaluation results.

Comparative Example 3 The following composition (5) was prepared in place of composition (1) with reference to the examples described in JP-A-57-107885. Composition (5) Component Compounding amount 100 parts by weight of polyester resin (manufactured by Toyobo: RV200) 5 parts by weight of silicone oil (manufactured by Toray Dow Corning: SH3746), mixed solvent of toluene / 2-butanone = 1/1 595 Parts by weight. Preparation of Thermal Transfer Recording Sheet The above composition (5) was prepared by adding 100 μm thick white PETG.
Using a copolyester film (trademark: Trepaloy GW, manufactured by Toray Synthetic Film Co., Ltd., details of the glycol component of the base film are described in Table 2), the coating solution is dried on one side of the coating film with a # 10 wire bar.・ Coating amount after curing is 10
g / m ² and dried at 100 ° C. for 1 minute. The accelerating voltage is 175kV and the absorbed dose is 7M from the coated surface.
The composition (5) was cured by irradiating an electron beam under the conditions of rad and an oxygen concentration of 500 ppm or less to obtain a thermal transfer recording sheet of the present invention, which was evaluated in the same manner as in Example 1. Table 3 shows the evaluation results.

Comparative Example 4 The same operation as in Example 1 was performed. However, the composition (2) was prepared in place of the composition (1), and a 100-μm thick white PET film (trade name: Tetron U2, manufactured by Teijin Dupont Film Co., Ltd., base film) The details of the glycol component are described in Table 2.)
It was used. Table 3 shows the evaluation results.

[0053]

[Table 1]

[0054]

[Table 2] The acid component of the polyester resin support in Table 2 is terephthalic acid.

[0055]

[Table 3]

As clearly shown in Table 3, the thermal transfer recording sheet according to the present invention does not impair the appearance of the support due to drying by heating, has good dye-dyeing properties, and has a card-forming property. Molding processability was good (Examples 1 to 3). A radiation-curable compound coating liquid according to the present invention which is essentially liquid (that is, an embodiment containing no solvent)
By using, heat drying after coating is not required, and the appearance of the sheet-shaped support is not impaired (Example 1).
And 3). Furthermore, even if the radiation-curable compound coating liquid according to the present invention contains a small amount of organic solvent in the coating liquid and the paint needs to be heated and dried, the radiation-curable compound coating liquid according to the present invention uses a solvent. Since the amount can be suppressed, the appearance of the thermal transfer recording sheet is not impaired as long as it is within the softening point of the on-sheet support according to the present invention (Example 2).

Even when the casting method was used (Example 3), the effect of the thermal transfer recording sheet according to the present invention was not changed, and was sufficiently practical. However, even if only the sheet-like support according to the present invention is made into a card, the dye lineability is not sufficient and it cannot be put to practical use (Comparative Example 1). In addition, it is clear that the thermal transfer recording sheet prepared by the prior art and produced by radiation curing is inferior in dye-dyeing properties (Comparative Example 2). On the other hand, when a known dye-receiving layer having good dye-dyeability is applied, the appearance of the sheet is impaired by heating and drying (Comparative Example 3). To prevent this, cyclohexane is added to the glycol structure other than the present invention. When a sheet (PET film) made of polyester containing no dimethanol structure was used, the molding processability was unsuitable, and it was not practically usable (Comparative Example 4).

[0058]

According to the present invention, a sheet-like support mainly composed of a copolyester resin having a 1,4-cyclohexanedimethanol structure in a glycol component to be polycondensed, and a radiation-curable compound is formed on at least one surface of the support. In a thermal transfer recording sheet having a cured resin layer formed by applying a coating composition containing as a main component and radiation curing the composition,
By containing the urethane / unsaturated organo-oligomer as a radiation-curable compound in the coating composition preferably in an amount of at least 10% by weight based on the total weight of the cured resin layer of 100% by weight, the appearance is impaired in the drying process after coating. Also, it is excellent in moldability for carding, and it is possible to form a dyed image by diffusing and transferring a dye by heating. In addition, the present invention is a thermal transfer recording sheet capable of transferring a softening-melting ink under heat to clearly print characters and the like at a high density. Furthermore, images and characters such as photographs required for cards such as a magnetic card utilizing magnetic characteristics used as an information recording medium and an IC card having a built-in IC chip which is a large-capacity variable information recording medium are required. An object of the present invention is to provide a thermal transfer recording sheet capable of printing and printing both information with high image quality.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H111 CA03 CA25 CA30 4F006 AA35 AB42 BA01 CA01 4J027 AC02 AC06 AG03 AG04 AG09 AG13 AG14 AG23 AG24 AG27 AG33 AJ01 AJ02 BA06 BA07 BA08 BA10 BA11 BA12 BA13 BA15 BA16 BA19 BA20 BA21 BA23 BA24 BA26 BA27 BA28 CC06 CD10

Claims (5)

[Claims] 1. A radiation-curable composition comprising a sheet-like support containing a copolyester resin containing cyclohexanedimethanol in a glycol component to be polycondensed, and a coating composition containing a radiation-curable compound applied on at least one surface thereof. A thermal transfer recording sheet having a cured resin layer formed by the above method, wherein the radiation-curable compound is represented by the following general formula (1):
A thermal transfer recording sheet containing a urethane / unsaturated organo oligomer represented by the formula: Embedded image (Wherein dehydrogenation residue of a polymer diol of -OR ¹ O-is the number average molecular weight 200 to 2000, -R ² - organic diisocyanate residue, -OR ³ O-is, dehydration of the hydroxyl groups of the dihydroxyl compound And CH ₂ ＣC (R
⁵ ) COOR ⁴ O— is a dehydrogenated residue of a hydroxyl group-containing (meth) acrylate ester having one or more double bonds, R ⁵ is a hydrogen atom or a methyl group, and R ⁴ is a dihydric alcohol residue. Groups are shown below. N represents an integer of 1 to 100. ) 2. The thermal transfer recording sheet according to claim 1, wherein the elongation onset temperature (softening point) of the sheet-like support is 50 ° C. or more and 140 ° C. or less determined by a temperature rise test using a thermomechanical property tester. 3. In the copolyester resin,
3. The thermal transfer recording sheet according to claim 1, wherein 1,4-cyclohexanedimethanol is contained in an amount of 5 mol% or more in 100 mol% of the glycol component. 4. The thermal transfer recording sheet according to claim 1, wherein the copolyester resin is obtained by polycondensing a monomer containing terephthalic acid, ethylene glycol and 1,4-cyclohexanedimethanol. 5. The thermal transfer recording sheet according to claim 1, wherein the urethane / unsaturated organo oligomer is contained in an amount of 10% by weight or more based on 100% by weight of the total weight of the curable resin layer.