JPH04286688A - Image receiving sheet for thermal transfer recording and protective sheet for thermal transfer recording - Google Patents

Abstract

PURPOSE:To hold a clear image by preventing a blur of dyestuff from occurrence for a long time by a method wherein a support having many fine holes opened in a direction actually vertical to an image receiving surface, and a thermally diffusive dyestuff acceptive material with which the fine holes are filled, are provided. CONSTITUTION:A thermal transfer recording image receiving sheet thermally diffuses sublimate dyestuff coming by diffusion with heat only in a direction actually normal to a plane in the image receiving sheet, and does not diffuse it in a plane direction in the image receiving sheet. As an example of a support of the thermal transfer recording image receiving sheet, the support 1 is of a simple layer 1a. Many fine holes 2 are opened in the direction actually normal to said image receiving surface, and those fine holes 2 are filled with the thermally diffusive dyestuff acceptive material 3. A thermal transfer recording protective sheet is also as same in a mode as the thermal transfer recording image receiving sheet excepting that the thermally diffusive dyestuff acceptive material 3 is taken as an adhesive material 6.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to an image-receiving sheet for thermal transfer recording and a protective sheet for thermal transfer recording. The present invention relates to an image receiving sheet for thermal transfer recording and a protective sheet for thermal transfer recording.

0002

BACKGROUND OF THE INVENTION Conventionally, color recording techniques such as inkjet, electrophotography, and thermal transfer recording have been studied as methods for obtaining color hard copies. Among these, the thermal transfer recording method in particular has advantages such as easy operation and maintenance, miniaturization of the device, and low cost.

[0003] There are two types of this thermal transfer recording system as follows. Specifically, there is a method in which a transfer sheet having a meltable ink layer on a support is imagewise heated with a laser or a thermal head to melt and transfer the meltable ink layer onto an image-receiving sheet for thermal transfer recording; Thermal diffusion transfer method uses an ink sheet for thermal transfer recording having an ink layer containing a thermal diffusible dye (sublimable dye) to diffusely transfer the thermal diffusible dye to an image receiving sheet for thermal transfer recording. It is.

Among these, the thermal diffusion transfer method can control the gradation of the image by changing the amount of dye transferred according to changes in the thermal energy of the thermal head, so it is possible to In recent years, it has been attracting attention as a method for obtaining color images with continuous changes in color shading by performing overlapping recording.

However, the conventional thermal diffusion transfer method has various problems.

For example, the main problem is that conventional image-receiving sheets for thermal transfer recording do not have a good ability to prevent the image formed on the image-receiving layer from bleeding.

That is, when an image-receiving sheet for thermal transfer recording with an image formed on the image-receiving layer is stored for a long period of time, the heat-diffusible dye may diffuse and bleed from the outline of the image. It was difficult to maintain clarity over the entire period. Further, in order to protect images formed with heat-diffusible dyes and improve durability, it is often necessary to provide a protective film.

[0008] In particular, for image recording materials having gradation images such as color images formed by a sublimation type thermal transfer method, in order to prevent the sublimable dye forming the image from bleeding and discoloration due to ultraviolet rays, etc. It is necessary to take some kind of protective measures.

Furthermore, among image recording media, especially in the case of ID cards such as automobile licenses, there is a technology that not only provides high durability but also provides a protective film that is effective in preventing forgery and alteration. It is strongly requested.

[0010] Therefore, as a method of protecting the image on the card, lamination processing has been generally employed.

[0011] That is, an attempt is made to protect the image by laminating a transparent film or the like via a flat adhesive layer on the surface of an image recording medium on which a color image such as a face photograph or an image with text information is formed. be.

[0012] However, with cards on which such a protective layer is formed, the heat-diffusible dye may diffuse into the adhesive layer during storage or immediately after lamination, causing bleeding in the image. In this case, too, it was difficult to keep the image clear for a long period of time.

The present invention has been made to improve the above situation.

That is, an object of the present invention is to provide an image-receiving sheet for thermal transfer recording and a protective sheet for thermal transfer recording, which can prevent the occurrence of dye bleeding over a long period of time and can maintain clear images. Our goal is to provide the following.

[0015]

[Means for Solving the Problems] The present invention as set forth in claim 1 to achieve the above object provides a support having a large number of fine holes opened in a direction substantially perpendicular to an image receiving plane. and a heat-diffusible dye-receiving material filled in the fine pores, the invention according to claim 2 is an image-receiving sheet for thermal transfer recording, characterized in that it has In the image-receiving sheet for thermal transfer recording, the support is a single-layer sheet, and the invention according to claim 3 provides the image-receiving sheet for thermal transfer recording according to claim 1, wherein the support has no micropores. A heat-diffusible dye-receptive material comprising a support layer and a large number of micropores opened in a direction substantially perpendicular to the image-receiving plane, and the micropores are filled with a heat-diffusible dye-receptive material. The invention according to claim 4 has a layer, and the invention according to claim 4 provides the image-receiving sheet for thermal transfer recording according to claim 1, wherein the support is opened in a direction substantially perpendicular to a plane. 2. The photosensitive material according to claim 1, further comprising: a support layer having micropores and having the micropores filled with a heat-diffusible dye-receptive material; and a heat-diffusible dye-non-receptive material layer having no micropores. It is an image receiving sheet for thermal transfer recording, and the invention according to claim 5 provides a support having a large number of micropores opened in a direction substantially perpendicular to the surface, and an adhesive filling the micropores. A protective sheet for thermal transfer recording, characterized in that it has a substance, claim 6.
The invention according to claim 5 is the protective sheet for thermal transfer recording according to claim 5, wherein the support is a single layer sheet,
The invention according to claim 7 is the protective sheet for thermal transfer recording according to claim 5 or 6, wherein the support is formed of a heat-diffusible dye non-receiving material, and the protective sheet according to claim 8 The present invention provides a protective sheet for thermal transfer recording according to claim 5, wherein the support has a support layer without micropores and a large number of micropores opened in a direction substantially perpendicular to the surface. and a heat-diffusible dye non-receiving material layer formed by filling the fine pores with an adhesive substance. A support layer in which the support has micropores opened in a direction substantially perpendicular to the surface of the support, and the micropores are filled with an adhesive substance;
and a layer of a thermodiffusible dye non-receiving material without micropores.

The present invention will be explained in detail below.

A. Image-receiving sheet for thermal transfer recording The image-receiving sheet for thermal transfer recording of the present invention is produced by thermally diffusing the sublimable dye, which is diffused by heat, only in a direction substantially perpendicular to the plane of the image-receiving sheet. The principle is to prevent diffusion in the plane direction.

1. Support The support for the image-receiving sheet for thermal transfer recording of the present invention includes:
The following three aspects can be mentioned.

1. For example, as shown in FIG.
is a single layer 1a, a large number of micropores 2 are opened in a direction substantially perpendicular to the image-receiving surface, and the micropores 2 are filled with a thermally diffusible dye-receiving material 3.

2. For example, as shown in FIG.
a support layer 1b without micropores, and a heat-diffusible dye-receptive material layer 4 formed by filling micropores 2 formed substantially perpendicularly to the image-receiving surface with a heat-diffusible dye-receptive material 3. This is a case consisting of.

3. For example, as shown in FIG.
A support layer 1 is formed by filling micropores 2 substantially perpendicular to the image-receiving surface with a heat-diffusible dye-receiving material 3.
c, and a thermodiffusible dye non-receptive material layer 4 having no micropores.
This is a case consisting of a.

1. Regarding the case of: As the material for the single layer, various materials can be used without particular restrictions as long as they are resins that are difficult to dye with heat-diffusible dyes. Here, the difficulty in dyeing with a heat-diffusible dye means that dyeing with a heat-diffusible dye is difficult using a sublimation heat-sensitive transfer recording method using an image-receiving sheet for heat-sensitive transfer recording in which a heat-diffusible dye-receiving material is laminated on a resin sheet as a sample. After forming an image with a sublimable dye using the method, the image-receiving sheet for thermal transfer recording with the image was left at 100°C for 24 hours, sliced into 3 μm thick pieces, and the cross section was observed with a microtome to determine the dyeing on the resin sheet. The degree of dyeing was evaluated, and if no dyeing was observed, it was determined that dyeing was difficult.

Examples of such materials include polyarylate, polyacetal, polyethersulfone, polyethernitrile, polyetheretherketone, modified polyphenylene oxide, polyoxybenzylene,
polyimide, polyetherimide, polyamideimide,
Examples include heat-resistant polymers such as polyphenylene sulfide, polyparabanic acid resin, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, methacrylic resin, styrene resin, and polycarbonate.

In the single layer, white pigments such as titanium white, magnesium carbonate, zinc oxide, barium sulfate, silica, talc, clay, and calcium carbonate are added to improve the type of image required or the sharpness of the image. etc. may be added.

The thickness of the single layer is usually 20 to 1000 μm, preferably 20 to 800 μm, and is appropriately selected from within this range.

A large number of fine holes are formed in the single layer in a direction substantially perpendicular to the image receiving surface. The shape of the micropores is
Although there are no particular restrictions in the present invention, circular, elliptical, and rectangular shapes (quadrilaterals, triangles, polygons, etc.) are generally preferred.

It is preferable that the size of the micropores is sufficiently smaller than the dot diameter of the thermal head and the laser condensing diameter, which will be described later. Furthermore, the size of the micropores in terms of area in the single layer surface layer is usually in the range of 10-7 to 10-2 mm2, preferably in the range of 10-6 to 10-3 mm2. If the size of the micropores is less than 10-7 mm2, it may be difficult to fill with the heat-diffusible dye-receiving material, and if the size of the micropores exceeds 10-2 mm2, it may be difficult to visually inspect the material. In this case, the diffusion of the dye may be discernible, which is not preferable.

In the embodiment shown in FIG. 1, the depth of the micropores is usually 3 to 100 μm, preferably around 20 μm, although it depends on the thickness of the single layer.

In order to form a large number of fine holes in a single layer in a direction substantially perpendicular to the image receiving surface, known fine hole forming techniques such as the technique described in JP-A-2-121878 can be applied. . Among these, a method using laser light is preferable from the viewpoint of efficiency, reliability, and the like. When using this method, C
O2 gas lasers and YAG lasers can be used, but a heat-affected zone may be formed around the micropores, and burrs may occur when the melted resin hardens, so it is better to use an excimer laser, which is less likely to cause these problems. preferable.

As the heat-diffusible dye-receiving material to be filled in the micropores, a resin that is evaluated as having no difficulty in dyeing according to the above-mentioned evaluation of difficulty in dyeing can be used. As such a heat-diffusible dye-receiving material, a material conventionally known as an image-receiving layer forming material of an image-receiving sheet for thermal transfer recording can be used. That is, the following binders can be used as this known material, and in some cases, this binder and various additives can be used in combination.

Examples of the binder include polyvinyl chloride resins, copolymer resins of vinyl chloride and other monomers (eg, isobutyl vinyl ether, vinyl propionate, etc.), polyester resins, acrylic esters,
Polyvinylpyrrolidone, polycarbonate, cellulose triacetate, polystyrene, copolymers of styrene and other monomers (e.g. acrylic ester, acrylonitrile, chlorinated ethylene, etc.), vinyltoluene acrylate resin, polyurethane resin, polyamide resin, urea resin, epoxy Examples include resins, phenoxy resins, polycaprolactone resins, and polyacrylonitrile resins.

The above various resins may be newly synthesized and used, but commercially available products may also be used.

In any case, from the viewpoint of physical properties, the binder has a glass transition point (Tg) of -80 to
Resins in the range of 150°C, particularly resins in the range of -20 to 120°C, are preferred, and from the viewpoint of molecular weight,
Resins with Mw in the range of 500 to 100,000 are preferred.

[0034] When filling the micropores, the above-mentioned various resins utilize their reactive active sites (if there are no reactive active sites, they are added to the resin), and radiation, heat, moisture, It may be crosslinked or cured using a catalyst or the like.

In that case, a radiation active monomer such as epoxy or acrylic or a crosslinking agent such as isocyanate can be used.

Next, as additives that can be used in combination with the binder, release agents, antioxidants, UV absorbers, light stabilizers, fillers (inorganic fine particles, organic resin particles), pigments, plasticizers (sensitizers), etc. ), thermal solvents (sensitizers), etc.

The release agent can improve the releasability between the ink sheet for thermal transfer recording and the image-receiving sheet for thermal transfer recording. Such release agents include silicone oil (including what is called silicone resin); solid waxes such as polyethylene wax, amide wax, and Teflon powder; fluorine-based and phosphoric acid ester-based surfactants, etc. Among them, silicone oil is preferred. There are two types of silicone oil: a type in which it is simply added (simple addition type) and a type in which it is cured or reacted (curing reaction type).

In the case of a simple addition type, it is preferable to use a modified silicone oil (eg, polyester modified silicone resin, urethane modified silicone resin, acrylic modified silicone resin, etc.) in order to improve the compatibility with the binder. The amount of these simple addition type silicone oils can vary depending on the type, so it cannot be determined uniformly, but generally speaking,
Usually, it is 0.1 to 50% by weight based on the binder,
Preferably it is 0.5 to 20% by weight.

[0039] As curing reaction type silicone oil,
Reaction curing type (for example, reaction curing of amino-modified silicone oil and epoxy-modified silicone oil)
, photocuring type, catalyst curing type, etc. The amount of these curable silicone oils added is 0.5 to 30% of the binder.
Weight percent is preferred.

[0040] After dissolving or dispersing the above-mentioned release agent in a suitable solvent and applying it to a part of the surface of the support 1,
A release agent layer can also be provided by drying or the like.

[0041] As the antioxidant, JP-A-59-1
No. 82785, No. 60-130735, JP-A-1-1
Antioxidants described in publications such as No. 27387, and compounds known to improve image durability in photographs and other image recording materials can be mentioned. The UV
As absorbers and light stabilizers, JP-A-59-1582
No. 87, No. 63-74686, No. 63-145089
No. 59-19692, No. 62-229594,
Examples include compounds described in publications such as JP-A No. 63-122596, JP-A No. 61-283595, and JP-A-1-204788, as well as compounds known to improve image durability in photographs and other image recording materials. .

[0042] Examples of the filler include inorganic fine particles and organic resin particles.

Examples of the inorganic fine particles include silica gel, calcium carbonate, titanium oxide, acid clay, activated clay, alumina, etc., and examples of the organic fine particles include fluororesin particles, guanamine resin particles, acrylic resin particles, silicone resin particles, etc. The following resin particles can be mentioned. These inorganic/organic resin particles vary depending on the specific gravity, but are between 0 and 2.
Addition of 0% by weight is preferred.

Typical examples of the pigment include titanium white, calcium carbonate, zinc oxide, barium sulfate, silica, talc, clay, kaolin, activated clay, and acid clay.

[0045] As the plasticizer, phthalate esters,
Examples include trimellitic acid esters, adipic acid esters, other monobasic or polybasic acid esters, phosphoric acid esters, glycol esters, and the like.

In the present invention, the total amount of additives added is usually in the range of 0.1 to 50% by weight based on the binder.

Next, there is a method of filling the fine pores with a heat-diffusible dye-receiving material, and for example, the following method is practically preferred.

That is, the resin film without micropores was
After stacking more than one film and taking steps to prevent air from entering between each film (such as passing it through a calendar roll),
A large number of micropores are created in each film using an excimer laser. Next, while fixing the films so that they do not shift relative to each other, a solution in which a heat-diffusible dye-receiving material is dispersed or dissolved in a solvent is applied to the surface of the film and permeated into the fine pores to fill it. Further, if necessary, ultrasonic vibrations are applied, and then the solvent is gradually evaporated, and when the film surface becomes semi-dry, the film is slowly peeled off one by one from the surface layer. At this time, the surface film is not used because the heat-diffusible dye-receiving material will adhere to areas other than the micropores. The peeled film is dried one by one to completely dry the heat-diffusible dye-receiving material in the micropores.

As described above, the image-receiving sheet for thermal transfer recording of the present invention can be obtained.

Typical examples of the above-mentioned solvents include water, alcohol, methyl ethyl ketone, toluene, dioxane, cyclohexanone, and other known solvents for coating that have been conventionally used in forming the image-receiving layer. For the coating, conventionally known coating methods using a gravure roll, extrusion coating method, wire bar coating method, roll coating method, etc. can be employed.

This first aspect 1. In the case, support 1
The surface where the micropore openings are located becomes the image receiving surface. In addition, the surface with the opening of the micropore becomes the image receiving surface.
Second aspect 2. and third aspect 3. The same applies to

2. Regarding the case of: As the material for forming the support layer without micropores, the same material as that for the single layer can be used. The thickness of the support layer is usually 25 to 1000 μm, preferably 50 to 800 μm.

As the material for forming the heat-diffusible dye non-receiving material layer, any material that is evaluated to have no dyeability at all according to the dyeing difficulty evaluation method described above can be used as appropriate, such as polyester. arylate, polyether sulfone,
Polyacetal, polyethernitrile, polyetheretherketone, modified polyphenylene oxide, polyoxybenzylene, polyetherimide, polyamideimide, polyphenylene sulfide, polyparabanic acid resin, polysulfone, polycarbonate, polyimide, polyethylene terephthalate, polybutylene terephthalate, polyethylene terenaphthalate , heat-resistant resins such as polyacrylic acid resin, polymethacrylic acid resin, polystyrene, styrene resin, polyphenylene oxide,
Examples include polyvinyl chloride, polyvinylidene chloride, fluorinated resins, etc. Among these, polyarylate, polysulfone, polycarbonate, polyimide, polyethylene terephthalate, polybutylene terephthalate, styrene resins such as polystyrene, polyvinyl chloride,
Polyvinylidene chloride and the like can be suitably used. The thickness of the heat diffusible dye non-receiving material layer 4 is usually 3 to 25 mm.
0 μm, preferably 6 to 150 μm.

For details of the fine pores formed in the heat-diffusible dye-receiving material layer and the heat-diffusible dye-receiving material filled therein, see 1. This is the same as described in section.

Further, the surface where the micropores are opened becomes the image-receiving layer contact surface that comes into contact with the image-receiving surface.

2. In this case, in order to obtain the image-receiving sheet for thermal transfer recording of the present invention, a support layer forming material is applied to one side of the heat-diffusible dye-non-receptive material layer whose fine pores are filled with the heat-diffusible dye-receptive material. Either by melt-extruding and laminating, or by melt-extruding and laminating a material for forming a heat-diffusible dye non-accepting material layer on one side of the support layer, or by dispersing or dissolving the forming material in a solvent to form a coating solution. A heat-diffusible dye non-receptive material layer is formed by coating and drying this on one side of a support, micropores are opened in this layer by applying the above-mentioned micropore opening technique, and heat is applied to this layer. It may be filled with a diffusible dye-receiving material.

3. Regarding the case of Embodiment 1. The material for forming the support layer 1c is as follows. It may be the same as the support 1a in . The details of the micropores opened substantially perpendicularly to the support 1c and the heat-diffusible dye-receiving material are also described in Embodiment 1. The details of the heat-diffusible dye non-receiving material layer a are the same as those described in Embodiment 2. This is the same as the thermally diffusible dye non-accepting material layer described in .

This aspect 3. In this case, in order to produce the image-receiving sheet 1 for thermal transfer recording of the present invention, for example, a coating liquid is prepared by dispersing or dissolving the material for forming the heat-diffusible dye non-receptive material layer 4a in a solvent, is coated and dried on one side of the support 1c whose fine pores 2 are filled with a heat-diffusible dye-receptive material, or a material for forming the heat-diffusible dye-non-receptive material layer 4a is coated on one side of the support 1c. All you have to do is melt extrude and laminate. In addition, first, a laminate of the heat-diffusible dye non-receptive material layer 4a and the support 1c without micropores is manufactured, and later micropores are opened in the support 1c using the above-mentioned micropore opening technique, and then the layer is heated. It may also be filled with a diffusible dye-receiving material.

The above-mentioned solvents include ketone type (for example, methyl ethyl ketone, cyclohexanone, etc.), ether type (for example, dibutyl ether, tetrahydrofuran, dioxane, etc.), aromatic type (for example, toluene, xylene, etc.), and halogen type (for example, methylene chloride, etc.). (trichloroethylene, chlorobenzene, etc.), ester-based (e.g., butyl acetate, etc.), alcohol-based (e.g., isopropanol, ethyl cellosolve, etc.), hydrocarbon-based (e.g., octane, etc.)
etc. can be mentioned.

Further, as the coating method, conventionally known coating methods using a gravure roll, extrusion coating method, wire bar coating method, roll coating method, etc. can be employed.

2. Other Layers In FIGS. 1 to 3, a writing layer can be provided on the lower surface (on the side opposite to the image receiving surface) of the single layer 1a, the support layer 16, and the heat-diffusible dye non-receiving layer 4a.

[0062] When the image-receiving sheet for thermal transfer recording having an image is to be used as an ID card such as a car license, it is particularly preferable to provide a writing layer. After forming the writing layer,
This is because it is convenient because various information can be written on the ID card.

The explanation regarding the writing layer in the present invention is replaced by the explanation regarding the "writing layer" described in JP-A-1-205155 from line 14 in the upper right column on page 4 to line 2 in the lower right column on page 4. , a detailed explanation thereof will be omitted.

A backing layer may also be provided on the lower surface for the purpose of preventing static electricity and curling.

B. Protective sheet for thermal transfer recording The above A except that the heat-diffusible dye-receiving material is the adhesive substance 6.
The contents are the same as those described in the section on heat-receiving sheets.

That is, this protective sheet for thermal transfer recording can also take three forms as shown in FIGS. 4, 5, and 6. Note that in these figures, the same reference numerals as in FIGS. 1 to 3 indicate the same names.

The materials for forming the single layer, the support layer and the support 1c are as described above for the image-receiving sheet for thermal transfer recording, but in this protective sheet for thermal transfer recording, a substantially transparent material is used. Preferably, materials such as polyethylene terephthalate, polyarylate, polystyrene, methacrylate resins, etc. are used. The adhesive substance 6 may include a heat-melting substance and/or a low softening point thermoplastic resin. Moreover, a tackifier can be used in combination with these.

The heat-melting substances include vegetable waxes such as carnauba wax, wood wax, auriculie wax, and espar wax; animal waxes such as beeswax, insect wax, shellac wax, and spermaceti wax; paraffin wax, microcrystal wax, and polyethylene wax. , petroleum waxes such as ester waxes and acid waxes; and mineral waxes such as montan wax, ozokerite, and ceresin; and in addition to these waxes, palmitic acid, stearic acid, margaric acid, etc. and higher fatty acids such as behenic acid; higher alcohols such as palmityl alcohol, stearyl alcohol, behenyl alcohol, marganyl alcohol, myricyl alcohol and eicosanol; cetyl palmitate, myricyl palmitate, cetyl stearate and myricyl stearate; Examples include higher fatty acid esters; amides such as acetamide, propionic acid amide, palmitic acid amide, stearic acid amide and amide wax; and higher amines such as stearylamine, behenylamine and palmitylamine.

Examples of the thermoplastic resin having a low softening point include ethylene copolymers such as ethylene-vinyl acetate copolymer and ethylene-ethyl acrylate copolymer, polyamide resins such as nylon and dimer acid, and styrene-vinyl acetate copolymer. Polystyrene resins such as butadiene copolymers, styrene-isoprene copolymers, styrene-ethylene-butylene copolymers, polyester resins, polyolefin resins,
Examples include polyvinyl ether resins, polymethyl methacrylate resins, ionomer resins, cellulose resins, polyurethane resins, acrylic resins, epoxy resins, melamine resins, and vinyl chloride resins.

Examples of the tackifier include unmodified or modified rosin tackifiers, water-added rosin tackifiers, maleic acid tackifiers, polymerized rosin tackifiers, rosin phenol tackifiers, etc. Examples include rosin-based tackifiers, terpene-based tackifiers, petroleum resin-based tackifiers, and modified tackifiers thereof.

[0071] These tackifiers can be used singly or in combination of two or more.

The protective sheets for thermal transfer recording of the three embodiments described above can be used as they are, but a support member is preferably provided on the surface opposite to the surface on which the micropores are opened, preferably with a release layer interposed therebetween. By doing so, it can also be used as a protective sheet for thermal transfer recording with a supporting member.

[0073] In either the protective sheet for thermal transfer recording or the protective sheet for thermal transfer recording with a supporting member,
Its size is arbitrary. When the image-receiving sheet for thermal transfer recording is card-sized, the protective sheet for thermal transfer recording or the protective sheet for thermal transfer recording with a support member may also be card-sized, or may be a wide original fabric. When the protective sheet for thermal transfer recording or the protective sheet for thermal transfer recording with a support member is a wide original, the protective sheet for thermal transfer recording or the protective sheet for thermal transfer recording with a support member is added to the card-sized protective sheet for thermal transfer recording. When transferring the protective sheet for thermal transfer recording from the protective sheet, perforations or cuts are provided in the protective sheet for thermal transfer recording to divide a predetermined area, and the required area of the protective sheet for thermal transfer recording can be transferred. It is convenient to do so.

C. Production of image recording material Using the image-receiving sheet for thermal transfer recording of the present invention or the protective sheet for thermal transfer recording and using an ink sheet for thermal transfer recording, or the image-receiving sheet for thermal transfer recording and a general image-receiving sheet for thermal transfer recording. An image recording body can be manufactured by using the ink sheet for printing and the protective sheet for thermal transfer recording of the present invention.

(1) Ink sheet for thermal transfer recording The ink sheet for thermal transfer recording can basically be composed of a support and an ink layer formed thereon.

-Ink layer- The ink layer contains a heat-diffusible dye and a binder as essential components.

1. Heat-diffusible dyes Examples of heat-diffusible dyes include cyan dyes, magenta dyes, and yellow dyes.

[0078] As the cyan dye, JP-A-59-7
No. 8896, No. 59-227948, No. 60-249
No. 66, No. 60-53563, No. 60-130735
No. 60-131292, No. 60-239289, No. 61-19396, No. 61-22993, No. 6
No. 1-31292, No. 61-31467, No. 61-3
No. 5994, No. 61-49893, No. 61-1482
No. 69, No. 62-191191, No. 63-91288
Examples include naphthoquinone dyes, anthraquinone dyes, and azomethine dyes described in publications such as No. 63-91287 and No. 63-290793.

[0079] As the magenta dye, JP-A-59-
No. 78896, JP-A-60-30392, JP-A-60
-30394, JP 60-253595, JP 61-262190, JP 63-5992, JP 63-205288, JP 64-159, JP 64-63194 Examples include anthraquinone dyes, azo dyes, azomethine dyes, etc., which are described in various publications such as No.

[0080] As the yellow dye, JP-A-59-
No. 78896, JP-A-60-27594, JP-A-60
-31560, JP-A-60-53565, JP-A-6
Examples include methine dyes, azo dyes, quinophthalone dyes, and anthrisothiazole dyes described in publications such as No. 1-12394 and JP-A-63-122594.

Particularly preferred as the heat-diffusible dye is a compound having an open-chain or closed-chain active methylene group, and an oxidized product of a p-phenylenediamine derivative or a p-phenylenediamine derivative.
Azomethine dye obtained by a coupling reaction with an oxidized product of an aminophenol derivative and indoaniline obtained by a coupling reaction with an oxidized product of a phenol or naphthol derivative or a p-phenylenediamine derivative or an oxidized product of a p-aminophenol derivative. It is a pigment.

The heat-diffusible dye contained in the ink layer may be any of a yellow dye, a magenta dye, and a cyan dye, as long as the image to be formed is monochromatic. Furthermore, depending on the color tone of the image to be formed, it may contain two or more of the three types of dyes or other heat-diffusible dyes.

[0083] The amount of the heat diffusible dye used is usually 0.1 to 20 g, preferably 0.2 to 20 g per m2 of support.
It is 5g.

2. Binders for the ink layer include cellulose resins (for example, nitrocellulose, ethyl cellulose, etc.), vinyl resins such as polyvinyl alcohol, polyvinyl formal, polyvinyl acetoacetal, polyvinyl butyral, styrene resins, acrylic resins, methacrylic resins, Examples include rubber resins, ionomer resins, olefin resins, and the like. Among these resins, preferred are polyvinyl formal, polyvinyl butyral, polyvinyl acetoacetal, or cellulose resins, which have excellent dye retention ability. The above-mentioned various binders can be used alone or in combination of two or more.

The weight ratio of the binder to the heat-diffusible dye is preferably from 1:10 to 10:1, particularly preferably from 2:8 to 8:2.

3. Other Optional Components Furthermore, various additives may be added to the ink layer as long as they do not impede the object of the present invention.

The additives include fillers such as fine metal powder, silica gel, metal oxide, carbon black, and fine resin powder, mold release agents such as silicone resin and fluororesin, and curing agents that can react with the binder component ( Examples include radiation active compounds such as isocyanates, acrylics, and epoxies. Furthermore, heat-melting substances such as wax and higher fatty acid esters may be used as additives to promote transfer.
Compounds described in Japanese Patent No. 06997 can be mentioned.

-Support- Any support for the ink sheet for thermal transfer recording may be used as long as it has good dimensional stability and can withstand the heat during recording with a thermal head, including condenser paper and glassine paper. Heat-resistant plastic films such as tissue paper, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyamide, polycarbonate, polysulfone, polyvinyl alcohol, cellophane, polystyrene, polyimide can be used.

The thickness of the support is preferably 2 to 10 μm, and the support has a subbing layer for the purpose of improving adhesion with the binder and preventing transfer and dyeing of the dye to the support. You can leave it there. Furthermore, a backing layer may be provided on the back surface of the support (the side opposite to the ink layer) for purposes such as running stability, heat resistance, and antistatic properties.

[0090] The thickness of this subbing layer and backing layer is usually 0.1 to 1 μm.

[0091] There are no particular restrictions on the shape of the support;
For example, it can be of any shape, such as wide sheets or films, or narrow tapes or cards.

The thickness of the ink layer thus formed is usually 0.2 to 10 μm, preferably 0.3 to 3 μm.
It is μm.

[0093] The ink sheet for thermal transfer recording includes:
Convenience in use can be achieved by forming perforations or providing detection marks for detecting the positions of areas with different hues.

Furthermore, the ink sheet for thermal transfer recording is
The structure is not limited to the support and the heat-sensitive layer formed thereon, and other layers may be formed on the surface of the ink layer.

For example, an overcoat layer may be provided for the purpose of preventing set-off (blocking) of the heat-diffusible dye.

(2) Formation of an image (thermal transfer recording) To form an image, the ink layer of the ink sheet for thermal transfer recording and the image receiving surface of the image receiving sheet for thermal transfer recording of the present invention are superimposed, and the resulting laminated layer is Gives heat energy to things.

In this way, the heat-diffusible dye in the ink layer vaporizes or sublimates in an amount corresponding to the applied thermal energy, and diffuses into the fine pores of the image-receiving sheet for thermal transfer recording. As a result, an image is formed on the image receiving layer.

In the present invention, since the heat-diffusible dye-receptive material is filled in a large number of micropores opened perpendicularly to the image-receiving surface, the heat-diffusible dye travels vertically within the receptor material. It migrates along the direction, but not laterally.

[0099] Therefore, the obtained image will not be blurred and will have extremely high definition (sharpness).

[0100] The heat source for providing the thermal energy is as follows:
A thermal head is generally used, but other known devices such as a laser beam, an infrared flash, and a thermal pen can also be used.

When a thermal head is used as a heat source for applying thermal energy, the applied thermal energy can be varied continuously or in multiple stages by modulating the voltage or pulse width applied to the thermal head.

[0102] When using laser light as a heat source for providing thermal energy, the heat energy provided can be changed by changing the amount of laser light and the irradiation area.

In this case, in order to easily absorb laser light, a laser light absorbing material (for example, in the case of a semiconductor laser, carbon black or an infrared absorbing substance) is placed in or near the ink layer, or a thermally diffusive dye. It may be present within a receptive material.

When using a laser beam, it is preferable to bring the ink sheet for thermal transfer recording and the image-receiving sheet for thermal transfer recording into close contact with each other.

[0105] If a dot generator incorporating an acousto-optic element is used, thermal energy can be applied depending on the size of halftone dots.

[0106] When an infrared flash lamp is used as a heat source for providing thermal energy, heating is preferably performed through a colored layer such as black, as in the case of using laser light.

[0107] Alternatively, heating may be performed through a pattern or halftone dot pattern that continuously expresses the shading of an image, such as black, or a colored layer such as black on one side and a negative of the above pattern. Heating may be performed in combination with negative patterns. Thermal energy may be applied from the ink sheet side for thermal transfer recording, from the image receiving sheet side for thermal transfer recording, or from both sides, but if priority is given to effective use of thermal energy, It is desirable to perform this from the ink sheet side for thermal transfer recording.

[0108] By the above thermal transfer recording, a one-color image can be recorded on the image-receiving layer of an image-receiving sheet for thermal transfer recording, but according to the method described below, it is possible to obtain a color photo-like color image consisting of a combination of each color. You can also do it.

For example, by sequentially replacing yellow, magenta, cyan, and, if necessary, black thermal transfer recording sheets and performing thermal transfer according to each color, a photographic color image consisting of a combination of each color is obtained. You can also do that.

[0110] In addition, the following method is also effective. That is, instead of using ink sheets for heat-sensitive transfer recording of each color as described above, an ink sheet for heat-sensitive transfer recording is used that has areas pre-painted in each color.

[0111] First, the yellow area is used to thermally transfer the yellow color separation image, and then the magenta area is used to thermally transfer the magenta color separation image. , and, if necessary, a method of thermally transferring the black color image in this order.

[0112] Although it is possible to obtain a color photographic-like color image with this method, a further advantage of this method is that there is no need to replace the heat-sensitive sheet for heat-sensitive transfer recording as described above. There is.

Furthermore, in the present invention, after forming an image,
For the purpose of improving image storage stability, the image-receiving sheet for thermal transfer recording may be heat-treated by the method described above. For example, heat treatment may be performed over the entire image forming surface using a thermal head using a portion of the ink sheet where no ink layer is provided, or additional heat treatment using a heat roll or the like may be performed. Further, when an infrared absorbing agent is contained, the image forming surface may be exposed using an infrared flash lamp.

[0114] In either case, the heating means does not matter;
Since the purpose is to further diffuse the dye into the image-receiving layer, it is effective and preferable to heat from the support side of the image-receiving layer.

(2) Formation of protective layer of image-bearing image-receiving sheet for thermal transfer recording The image-receiving sheet for thermal transfer recording having the image obtained in the above step is coated with a protective layer to increase durability and prevent forgery, falsification, etc. Further, it is preferable to form a protective layer on the image receiving surface. In addition to the image-receiving sheet for thermal transfer recording of the present invention, other general image-receiving sheets for thermal transfer recording, which are formed by providing an image-receiving layer without micropores on a support, may also be formed using a sublimable dye. It is preferable to form a protective layer on the image-receiving surface having an image. In any of the image-receiving sheets for thermal transfer recording, the protective sheet for thermal transfer recording explained in section B above is as follows:
used to achieve this purpose.

That is, when the support surface of the protective sheet for thermal transfer recording is superimposed on the image receiving surface of the image receiving sheet for thermal transfer recording having the above-mentioned image and bonded under heat, the adhesive filling the fine pores of the protective sheet for thermal transfer recording is bonded. Both sheets are bonded together by a substance.

In this case, both sheets are bonded with sufficient adhesive strength and cannot be separated.

[0118] Furthermore, the adhesive layer-forming materials that have been used in the past have a high dye diffusivity, and the dye diffuses during thermocompression bonding or during storage, resulting in blurring of the image. However, in the image-receiving sheet for thermal transfer recording with a protective layer obtained according to the present invention, the protective layer, that is, the support, has a large number of fine pores vertically opened in the layer, which are filled with an adhesive substance. Therefore, not only during thermocompression bonding but also even when stored for a long period of time, the heat-diffusible dye forming the image migrates in the adhesive material along the longitudinal direction and does not migrate in the lateral direction. Therefore, in this case as well, the image does not blur, and its clarity can be maintained for a long period of time.

[0119]

[Examples] Next, the present invention will be explained in more detail based on Examples and Comparative Examples. In addition, in the following, "part" means "part by weight".

(Example 1) - Manufacture of image-receiving sheet for thermal transfer recording - Three sheets of white polyethylene terephthalate film containing an inorganic filler (manufactured by Diafoil Co., Ltd.) each having a thickness of 125 μm were stacked and After passing the film through a calendar roll to prevent air from entering between the films, a large number of fine holes were created in each film in a direction perpendicular to the film surface using an excimer laser.

[0121] The excimer laser uses an ArF laser, the spot diameter is narrowed to a rectangle of 400 μm in length x 800 μm in width, and as a masking material, 10 circular holes with a diameter of 20 μm are made in an aluminum material with a thickness of 20 μm with an interval of 20 μm. We installed 4,000 pieces lined up horizontally. The laser pulse was set to 100 Hz, and 10 pulses were used to completely perforate the first and second sheets of the above stacked white polyethylene terephthalate films, and to make holes to an average depth of 20 μm in the third sheet. After irradiating the film with 10 pulses of laser,
Move 800 μm horizontally every 0.1 seconds and move 400 μm vertically.
A microporous zone was formed in an area of μm×160,000 μm in width. Next, the film was moved 400 μm in the vertical direction and the same operation as above was repeated. By repeating such operations, a white polyethylene terephthalate film having micropores provided in a 16 cm wide area was produced.

Next, while fixing each film so as not to shift from each other, the following heat-diffusible dye-receiving material coating solution was applied to the surface of the film and allowed to penetrate and fill into the micropores.

[0123] Coating liquid for thermally diffusible dye-receiving material;
PVC··················
4.0 parts [manufactured by Shin-Etsu Chemical Co., Ltd., TK-3
00] Vinyl chloride resin...
・・・・・・・・・5.5 parts [BASF, Laroflex MP25] Polyester modified silicone resin ・・・・・・・・・0.5 parts
[Manufactured by Shin-Etsu Silicone Co., Ltd., X-24-
8300] Methyl ethyl ketone...
・・・・・・・・・40 parts dioxane・
・・・・・・・・・・・・・・・40 copies
Cyclohexanone・・・・・・・・・・・・・・・
・10 copies.

[0124] Thereafter, the solvent was gradually evaporated, and when the film surface became half-dry, the films on the surface layer were slowly peeled off one by one. At this time, the two surface films were removed, the third film was dried, and the heat-diffusible dye-receiving material in the micropores was completely dried.

As described above, an image receiving sheet for thermal transfer recording having a structure as shown in FIG. 1 was obtained.

- Manufacture of ink sheet for thermal transfer recording - On the corona-treated surface of a 6 μm thick polyethylene terephthalate film [manufactured by Toray Industries, Inc.] as a support,
A coating liquid for forming an ink layer with the following composition is applied by wire bar coating method to a thickness of 1 μm after drying, and a silicone resin [manufactured by Dainichiseika Co., Ltd.] is coated on the back surface that has not been corona-treated. , SP-2105]
A droplet or two of a nitrocellulose solution containing the following was applied with a dropper and spread over the entire surface, and a backside treatment coating was performed to obtain an ink sheet for thermal transfer recording.

[0127] Coating liquid for forming an ink layer;
Thermodiffusible dye・・・・・・・・・・・・・・・・・・
...4.0 parts [Nippon Kayaku Co., Ltd., Kayaset Blue 714] Polyvinyl butyral...
・・・・・・・・・・・・・・・5.0 parts [Sekisui Chemical Co., Ltd., S-LEC BX-1] Methyl ethyl ketone・・・・・・・・・・・・81 parts Cyclohexanone・・・・・・・・・・・・
...10 copies.

-Image Formation- The ink sheet for thermal transfer recording and the image-receiving sheet for thermal transfer recording are overlapped so that the ink layer surface of the former is in contact with the image-receiving surface of the latter, and the ink sheet for thermal transfer recording is Output 0.4W using a thermal head from the support side
Image recording was performed by heating under the following conditions: /dot, pulse width of 0.3 to 10 msec, and dot density of 6 dots/mm.

-Evaluation- The image-receiving sheet for thermal transfer recording on which an image was formed in this manner was evaluated according to the following criteria. The results are shown in Table 1.

Fusion: A: The image receiving sheet for thermal transfer recording is smoothly peeled off from the ink sheet for thermal transfer recording. x: The image-receiving layer of the image-receiving sheet for thermal transfer recording is fused to the ink sheet for thermal transfer recording and does not peel off.

Prevention of dye bleeding: The image-receiving sheet for thermal transfer recording on which an image was recorded was left at 60° C. for one week, and then the degree of bleeding was visually judged. ○: Almost no bleeding is observed. ×: Bleeding was observed.

Sharpness: The density gradient at the edge of the printed area that gives a transfer OD of 2.0 during printing was measured using a microdensitometer, and evaluated based on the width required to change the density from 0 to 2.0. ○...Less than 10 μm×...10 μm or more.

(Example 2) A polystyrene film was prepared in the same manner as in Example 1, except that 30 sheets of polystyrene film with a thickness of 25 μm were used instead of the three sheets of white polyethylene terephthalate film stacked in Example 1. A large number of micropores were opened perpendicularly to the film surface. At this time, the micropores were completely formed up to the 30th sheet. Furthermore, the same heat-diffusible dye-receiving material as in Example 1 was filled into the micropores, and the solvent was gradually evaporated. When the film surface became half-dry, the surface film was slowly removed one by one. The film was peeled off and dried one by one. In this way, a film was obtained in which the through holes were filled with a heat-diffusible dye-receiving material.

[0134] Next, on one side of this film, a polyethylene terephthalate resin composition to which titanium oxide had been added was melted and extruded into a film form from an extruder (temperature 280°C), and then biaxially stretched to form a film with a thickness of 100 μm. A support was formed, and this support and the above-mentioned film filled with a heat-diffusible dye-receiving material in the through holes were thermally fused and laminated.

As described above, an image receiving sheet for thermal transfer recording having the structure shown in FIG. 2 was obtained. Thereafter, an ink sheet for thermal transfer recording was produced in the same manner as in Example 1, and an image was formed using this and the above image-receiving sheet for thermal transfer recording, and evaluation was performed. The results are shown in Table 1.

(Example 3) Micropores were formed in the same film as in Example 2 except that a 25 μm thick polyethylene terephthalate film was used in place of the polystyrene film in Example 2. Filled with heat-diffusible dye-receptive material.

[0137] Next, polyvinyl chloride containing titanium oxide was melted and extruded from an extruder (temperature: 190°C) into a film on one side of the film to a thickness of 50°C.
A 0 μm layer of thermally diffusible dye non-accepting material was laminated.

As described above, an image receiving sheet for thermal transfer recording having the structure shown in FIG. 3 was obtained. Thereafter, an ink sheet for thermal transfer recording was prepared in the same manner as in Example 1, and an image was formed using this and the above image-receiving sheet for thermal transfer recording, and evaluation was performed. The results are shown in Table 1.

(Example 4) An image receiving sheet for thermal transfer recording was manufactured in the same manner as in Example 1, and an image receiving sheet for thermal transfer recording was manufactured in the same manner as in Example 1 except that the ink layer forming coating liquid was changed to the following formulation. An ink sheet was manufactured. Next, the ink sheet for heat-sensitive transfer recording and the image-receiving sheet for heat-sensitive transfer recording are superimposed so that the surface of the ink layer of the former is in contact with the surface of the image-receiving layer of the latter, and the semiconductor is applied from the support side of the ink sheet for heat-sensitive transfer recording. Laser LT090MD/MF [wavelength 830nm
, a maximum light output of 100 mW, manufactured by Sharp Corporation] was condensed and a beam of approximately 80 μm in diameter was irradiated to form an image, and the resulting image was evaluated. The results are shown in Table 1.

[0140] Coating liquid for forming an ink layer;
Thermodiffusible dye・・・・・・・・・・・・・・・・・・
...4.0 parts [Nippon Kayaku Co., Ltd., Kayaset Blue 714] Polyvinyl butyral...
・・・・・・・・・・・・・・・4.7 parts [Sekisui Chemical Co., Ltd., S-LEC BX-1] Near-infrared absorber・・・・・・・・・・・・・・・・・・・・0.
3 parts [manufactured by Mitsui Toatsu Dye Co., Ltd., PA-1006
] Methyl ethyl ketone・・・・・・・・・・・・
... Part 81 Cyclohexanone ...
・・・・・・・・・・・・10 parts.

(Comparative Example 1) A conventionally known image-receiving sheet for thermal transfer recording was manufactured. That is, a paint for forming an image-receiving layer having the composition shown below was coated on the surface of a 125 μm thick white polyethylene terephthalate film (without micropores), similar to that used in Example 1 as a support, and dried. An image-receiving sheet for thermal transfer recording was obtained by forming an image-receiving layer.

[0142] Coating liquid for forming an image-receiving layer;
PVC···············
...5.0 parts [Manufactured by Shin-Etsu Chemical Co., Ltd., TK
-600] Vinyl chloride resin...
・・・・・・・・・・・・4.5 parts [BASF
[Manufactured by Shin-Etsu Silicone Co., Ltd., Laroflex MP25] Polyester modified silicone resin 0.5 part [Manufactured by Shin-Etsu Silicone Co., Ltd., X-24-
8300] Methyl ethyl ketone...
・・・・・・・・・・・・80 parts Cyclohexanone・・・・・・・・・・・・・10 parts.

Thereafter, an ink sheet for thermal transfer recording was produced in the same manner as in Example 1, and an image was formed using this and the image receiving sheet for thermal transfer recording, and the results were evaluated. The results are shown in Table 1.

(Example 5) A paint for forming an image-receiving layer having the following composition was prepared.

Coating liquid for forming image-receiving layer;
PVC···············
...5.0 parts [Manufactured by Shin-Etsu Chemical Co., Ltd., TK
-600] Vinyl chloride resin...
・・・・・・・・・・・・4.5 parts [BA
Laroflex MP25 manufactured by SF Corporation] Polyester modified silicone resin 0.
5 parts [manufactured by Shin-Etsu Silicone Co., Ltd., X-2]
4-8300] Methyl ethyl ketone...
・・・・・・・・・・・・・・・80 parts Cyclohexanone・・・・・・・・・・・・・・・10 parts.

[0146] The above coating solution for forming an image-receiving layer was applied onto a white polyethylene terephthalate film having a thickness of 125 μm and dried to form an image-receiving layer having a thickness of 20 μm, thereby obtaining an image-receiving sheet for thermal transfer recording.

- Manufacture of ink sheet for thermal transfer recording - On the corona-treated surface of a 6 μm thick polyethylene terephthalate film [manufactured by Toray Industries, Inc.] as a support,
A coating liquid for forming an ink layer with the following composition is applied by wire bar coating method to a thickness of 1 μm after drying, and a silicone resin [manufactured by Dainichiseika Co., Ltd.] is coated on the back surface that has not been corona-treated. , SP-2105]
A droplet or two of a nitrocellulose solution containing the following was applied with a dropper and spread over the entire surface, and a backside treatment coating was performed to obtain an ink sheet for thermal transfer recording.

[0148] Coating liquid for forming an ink layer;
Thermodiffusible dye・・・・・・・・・・・・・・・・・・
...4.0 parts [Nippon Kayaku Co., Ltd., Kayaset Blue 714] Polyvinyl butyral...
・・・・・・・・・・・・・・・5.0 parts [Sekisui Chemical Co., Ltd., S-LEC BX-1] Methyl ethyl ketone・・・・・・・・・・・・81 parts Cyclohexanone・・・・・・・・・・・・
...10 copies.

-Image Formation- The ink sheet for thermal transfer recording and the image-receiving sheet for thermal transfer recording are overlapped so that the surface of the ink layer of the former is in contact with the surface of the image-receiving layer of the latter, and the ink sheet for thermal transfer recording is formed. Output 0. using a thermal head from the support side.
Image recording was performed by heating under the conditions of 4 W/dot, pulse width of 0.3 to 10 msec, and dot density of 6 dots/mm.

- Manufacture of protective sheet for thermal transfer recording - In the same manner as in Example 1, nine sheets of polyethylene terephthalate film with a thickness of 50 μm were stacked and passed through a calendar roll to prevent air from entering between each film. A large number of micropores were created in each film in a direction perpendicular to the film surface using an excimer laser. The first to eighth sheets of the polyethylene terephthalate film were completely perforated, and the ninth sheet was perforated to an average depth of 20 μm.

Next, an image-receiving sheet for thermal transfer recording was prepared in the same manner as in Example 1, except that the following adhesive substance coating liquid was used in place of the heat-diffusible dye-receiving material coating liquid of Example 1. was produced, and the sheet was used as a protective sheet for thermal transfer recording.

As described above, a protective sheet for thermal transfer recording having a structure as shown in FIG. 4 was obtained.

[0153] Adhesive substance coating liquid;
Polyester resin・・・・・・・・・・・・・・・・・・
・20 copies [manufactured by Toyobo Co., Ltd., Byron 20]
0] Methyl ethyl ketone...
70 parts Cyclohexanone 10 parts.

- Formation of protective layer - The image-receiving sheet for thermal transfer recording having the image obtained in the image forming step and the protective sheet for thermal transfer recording are separated by an image-receiving surface of the former and a surface having micropores of the latter. They were stacked so that they were in contact with each other, and laminated at 130°C using a thermocompression roll.

Images on the obtained image-receiving sheet for thermal transfer recording with a protective layer were visually evaluated for bleeding immediately after lamination and after storage (1 week at 60°C), and the density gradient at the edge was determined by microdensity. It was measured with a tomometer. The results are shown in Table 2.

Preventing dye bleeding: Immediately after lamination and after being left at 60°C for one week, the degree of bleeding was visually judged, and the density gradient at the edge of the printed area giving a transfer OD of 2.0 was measured using a microdensitometer. It was measured and evaluated based on the width from density 0 to density 2.0. ◎・・・Blood is not observed. The measured value with a microdensitometer is less than 10 μm. ○: Almost no bleeding is observed. The measured value with a microdensitometer is 10 μm or more and less than 20 μm. △... Slight bleeding was observed. The measured value with a microdensitometer is 20 μm or more and less than 50 μm. ×... Bleeding was observed. The measured value with a microdensitometer is 50 μm or more.

(Example 6) The following adhesive coating solution was used in place of the heat-diffusible dye-receiving material coating solution of Example 2, and it was bonded by thermocompression to a 25 μm thick polyethylene terephthalate film. An image-receiving sheet for thermal transfer recording was produced in the same manner as in Example 2, except for the following, and the sheet was used as a protective sheet for thermal transfer recording. As described above, a protective sheet for thermal transfer recording having a structure as shown in FIG. 5 was obtained.

[0158] Adhesive substance coating liquid;
Ethylene-vinyl acetate copolymer・・・・・・・・・・・・
・20 parts [Mitsui DuPont Polychemicals (
Evaflex EV45X, manufactured by Co., Ltd.] Methyl ethyl ketone 35 parts Toluene 35 parts
・・・・・・35 parts cyclohexanone・
・・・・・・・・・・・・・・・・・・10 parts.

Thereafter, an image was formed on the image-receiving sheet for thermal transfer recording using the same image-receiving sheet for thermal transfer recording and the ink sheet for thermal transfer recording as in Example 5, and the image-receiving sheet for thermal transfer recording having this image and the above-mentioned image-receiving sheet for thermal transfer recording were formed. A protective layer was formed on an image-bearing image-receiving sheet for thermal transfer recording in the same manner as in Example 5 using the protective sheet for thermal transfer recording, and the bleeding of the image was evaluated. The results are shown in Table 2.

(Example 7) Using the following adhesive coating solution in place of the heat-diffusible dye-receiving material coating solution of Example 3, a 50 μm thick polymethacrylate resin was extruded into a film and heated. An image-receiving sheet for thermal transfer recording was produced in the same manner as in Example 3 except that a layer of a diffusible dye non-receiving material was laminated, and this sheet was used as a protective sheet for thermal transfer recording. As described above, a protective sheet for thermal transfer recording having a structure as shown in FIG. 6 was obtained.

[0161] Adhesive substance coating liquid;
Urethane resin・・・・・・・・・・・・・・・・・・
・Part 10 [Sumitomo Bayern Urethane (
Co., Ltd., Desmocol D400] Methyl ethyl ketone 40 parts Toluene 40 parts
・・・・・・40 parts cyclohexanone・
・・・・・・・・・・・・・・・・・・10 parts.
Thereafter, an image was formed on the image-receiving sheet for thermal transfer recording using the same image-receiving sheet for thermal transfer recording and the ink sheet for thermal transfer recording as in Example 5, and the image-receiving sheet for thermal transfer recording having this image and the above-mentioned thermal transfer recording were formed. A protective layer was formed on an image-bearing image-receiving sheet for thermal transfer recording in the same manner as in Example 5 using a protective sheet, and the bleeding of the image was evaluated. The results are shown in Table 2.

(Example 8) Thermal transfer recording was carried out in the same manner as in Example 7 except that the following adhesive substance coating liquid was used in place of the heat-diffusible dye-receiving material coating liquid in Example 7. A protective sheet was manufactured. As described above, a protective sheet for thermal transfer recording having a structure as shown in FIG. 6 was obtained.

[0163] Adhesive substance coating liquid;
Ethylene-vinyl acetate copolymer・・・・・・・・・・・・
・・Part 4 [Mitsui Dupont Polychemicals (
Co., Ltd., Evaflex EV210] Rosin ester ・・・・・・・・・・・・・・・・・・
・5 parts [Manufactured by Arakawa Chemical Industry Co., Ltd., Ester Gum 105] Polyethylene wax...
・・・・・・・・・・・・・・・1 part [Mitsui Hiwax 100P, manufactured by Mitsui Petrochemicals Co., Ltd.]
Methyl ethyl ketone・・・・・・・・・・・・
...30 parts Toluene...
・・・・・・・・・・・・・・・60 parts Cyclohexanone・・・・・・・・・・・・・・・1
0 copies.

Thereafter, an image was formed on the image-receiving sheet for thermal transfer recording using the same image-receiving sheet for thermal transfer recording and the ink sheet for thermal transfer recording as in Example 5, and the image-receiving sheet for thermal transfer recording having this image and the above-mentioned image-receiving sheet for thermal transfer recording were formed. A protective layer was formed on an image-bearing image-receiving sheet for thermal transfer recording in the same manner as in Example 5 using the protective sheet for thermal transfer recording, and the bleeding of the image was evaluated. The results are shown in Table 2.

(Example 9) A protective sheet for thermal transfer recording was produced in the same manner as in Example 5 except that a polyimide film was used in place of the polyethylene terephthalate film in Example 5. An image is formed using an image receiving sheet for thermal transfer recording and an ink sheet for thermal transfer recording, and an image is produced in the same manner as in Example 5 using the image receiving sheet for thermal transfer recording having this image and the above protection sheet for thermal transfer recording. A protective layer was formed on an image-receiving sheet for thermal transfer recording, and the bleeding of the image was evaluated. The results are shown in Table 2.

(Comparative Example 2) The adhesive coating solution of Example 5 was applied onto the same 50 μm thick polyethylene terephthalate film (without micropores) used in Example 5 and dried to form a 10 μm thick film. forming an adhesive layer of
A protective sheet for thermal transfer recording was obtained.

Thereafter, an image was formed using the same image-receiving sheet for thermal transfer recording and ink sheet for thermal transfer recording as in Example 5, and the image-receiving sheet for thermal transfer recording having this image and the above-mentioned protective sheet for thermal transfer recording were combined. A protective layer was formed on an image-bearing image-receiving sheet for thermal transfer recording using the same method as in Example 5, and the bleeding of the image was evaluated. The results are shown in Table 2.

(Comparative Example 3) The adhesive coating solution of Example 8 was applied onto the same 50 μm thick polyethylene terephthalate film (without micropores) used in Example 5 and dried to form a 10 μm thick film. forming an adhesive layer of
A protective sheet for thermal transfer recording was obtained.

Thereafter, an image was formed using the same image-receiving sheet for thermal transfer recording and ink sheet for thermal transfer recording as in Example 5, and the image-receiving sheet for thermal transfer recording having this image and the above protective sheet for thermal transfer recording were combined. A protective layer was formed on an image-bearing image-receiving sheet for thermal transfer recording using the same method as in Example 5, and the bleeding of the image was evaluated. The results are shown in Table 2.

(Example 10) An image was formed on the image receiving sheet for thermal transfer recording on which the image was formed in Example 1 in the same manner as in Example 5 using the protective sheet for thermal transfer recording manufactured in Example 5. A protective layer was formed on an image-receiving sheet for thermal transfer recording, and the bleeding of the image was evaluated. The results are shown in Table 2.

(Example 11) An image was formed on the image receiving sheet for thermal transfer recording on which the image was formed in Example 2 in the same manner as in Example 5 using the protective sheet for thermal transfer recording manufactured in Example 6. A protective layer was formed on an image-receiving sheet for thermal transfer recording, and the bleeding of the image was evaluated. The results are shown in Table 2.

(Example 13) An image was formed on the image receiving sheet for thermal transfer recording on which the image was formed in Example 3 in the same manner as in Example 5 using the protective sheet for thermal transfer recording manufactured in Example 7. A protective layer was formed on an image-receiving sheet for thermal transfer recording, and the bleeding of the image was evaluated. The results are shown in Table 2.

[0173]

[Table 1]

[0174]

[Table 2]

[0175]

[Effect of the invention] The image-receiving sheet for thermal transfer recording of the present invention is
Since the support has a large number of micropores that are perpendicular to the image-receiving plane and a heat-diffusible dye-receiving material filled in the micropores, the image can be stored even after being formed. The image does not smudge and retains its clarity over a long period of time. Further, the protective sheet for thermal transfer recording of the present invention includes a support for a protective sheet having a large number of micropores opened in a direction perpendicular to the surface of the support, and an adhesive substance filled in the micropores. Since we have
When bonded to an image-receiving sheet for thermal transfer recording with an image via an adhesive material, the image does not smear, maintains its clarity over a long period of time, is highly durable, and is not susceptible to forgery or alteration. An image receiving sheet for thermal transfer recording with a protective layer can be provided.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the structure of an image-receiving sheet for thermal transfer recording showing one embodiment of the present invention.

FIG. 2 is an explanatory diagram of the structure of an image-receiving sheet for thermal transfer recording showing another embodiment of the present invention.

FIG. 3 is an explanatory diagram of the structure of an image-receiving sheet for thermal transfer recording showing still another embodiment of the present invention.

FIG. 4 is an explanatory diagram of a structure of a protective sheet for thermal transfer recording showing one embodiment of the present invention.

FIG. 5 is an explanatory diagram of the structure of a protective sheet for thermal transfer recording showing another embodiment of the present invention.

FIG. 6 is an explanatory diagram of the structure of a protective sheet for thermal transfer recording showing still another embodiment of the present invention.

[Explanation of sign]

1 Support 1a Single layer 1b Support layer (no micropores) 1c Support layer (with micropores) 2. Micropores 3. Thermodiffusible dye-receiving material 4 Heat diffusible dye non-receptive material layer 4a Heat diffusible dye non-receptive material layer 5 Support for protective sheet 6 Adhesive substance

Claims (9)

[Claims] Claim 1: A support having a large number of micropores opened in a direction substantially perpendicular to an image-receiving plane, and a heat-diffusible dye-receiving material filled in the micropores. An image receiving sheet for thermal transfer recording. 2. The image-receiving sheet for thermal transfer recording according to claim 1, wherein the support is a single layer sheet. 3. The support has a support layer without micropores, a large number of micropores opened in a direction substantially perpendicular to the image-receiving plane, and a thermodiffusible dye-receiving property in the micropores. 2. The image-receiving sheet for thermal transfer recording according to claim 1, further comprising a heat-diffusible dye non-receiving material layer filled with a material. 4. A support layer in which the support has micropores opened in a direction substantially perpendicular to a plane, and the micropores are filled with a heat-diffusible dye-receiving material;
2. The image-receiving sheet for thermal transfer recording according to claim 1, further comprising a heat-diffusible dye non-receiving material layer without micropores. 5. A thermal transfer recording comprising: a support having a large number of micropores opened in a direction substantially perpendicular to the surface; and an adhesive substance filled in the micropores. protective sheet. 6. The protective sheet for thermal transfer recording according to claim 5, wherein the support is a single layer sheet. 7. The protective sheet for thermal transfer recording according to claim 5 or 6, wherein the support is formed of a heat-diffusible dye non-receiving material. 8. A thermally diffusive material in which the support has a support layer without micropores, a large number of micropores opened in a direction perpendicular to the surface, and the micropores are filled with an adhesive substance. 6. The protective sheet for thermal transfer recording according to claim 5, further comprising a dye non-receptive material layer. 9. A support layer in which the support has micropores opened in a direction perpendicular to the surface of the support and the micropores are filled with an adhesive substance; 7. The protective sheet for thermal transfer recording according to claim 6, further comprising a dye non-receiving material layer.