JPH02160586A - New thermosensitive transfer recording medium - Google Patents

Abstract

PURPOSE:To make possible printing on paper to be transferred with less surface smoothness, clearly and at high density by adding styrene-ethylene-propylene- styrene block copolymer and a specific thermally fusible material to a thermally fusible coloring material layer. CONSTITUTION:A thermally fusible coloring material layer is provided on a support directly or through an adhesive layer. This thermally fusible coloring material layer has a polystyrene terminal block, and an intermediate block contains one or two kinds of thermally fusible material selected from among a styrene-ethylene-propylene-styrene block copolymer resin with a crystalline ethylene-propylene rubber block, animal wax, vegetable wax, mineral wax, petroleum wax, compounded hydrocarbon wax and modified wax. In this case, the polystyrene content is within the range of 5 to 60% by weight, and the intermediate block contains a high percentage or 60% by weight of crystalline polyethylene and has an average molecular weight by weight ranging from 2,000 to 200,000.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a novel thermal transfer recording medium that is rich in blocking resistance, toughness, and durability of transferred images. More specifically, it can print with low energy, exhibits good print performance and print retention durability even on uneven paper such as plain paper, and provides clear, high-quality print quality. The present invention relates to a thermal transfer recording medium that can be used.

[Prior Art] As a conventional technology, heat-sensitive transfer recording media intended for multiple use have been disclosed, for example, in Japanese Patent Application Laid-open No. 55-105579, which has a fine porous layer. JP-A-57-160691 discloses a technique for forming a network structure using organic or inorganic fine powder and impregnating it with ink. Are listed.

Furthermore, JP-A-57-185192 describes a technique for impregnating porous paper with ink;
Publication No. 68253 discloses a technique in which a resin and a solid component immiscible therewith are dissolved and dispersed in a volatile solvent, and after the solvent evaporates, a fine porous layer of the resin component is formed on a support. Are listed.

Further, JP-A-61-162395 describes a technology for a thermal transfer recording medium made of polyethylene glycol diester or wax, which is solid at room temperature.

[Intelligence B to be Solved by the Invention] One of the above-mentioned conventional technologies is that they are all devised so that ink seeps out little by little from a porous solid base material. Because the solid base material forming the network structure does not melt or mix with heat-fusible substances when energy is applied, and the solid base material is not substantially transferred, as a result, the dye transfer image There is a problem that the density is low and does not give clear print quality, and in order to obtain high density and clear print, high energy is required, resulting in a significant decrease in resolution. have.

This kind of idea was introduced in Japanese Patent Application Laid-Open No. 35-1989. It can be said that the technique disclosed in Japanese Patent No. 13426 is simply applied to a thermal transfer ribbon, and due to the problem of the transfer principle, the printing sensitivity is extremely poor, which is inconvenient.

On the other hand, as an attempt to solve the first problem, there have been disclosed, for example, JP-A-57-36698 and JP-A-59-969.
In Publication No. 92, the transfer amount of the heat-melting coloring material layer is
As a technique to address this problem, the authors disclose a method of interposing an adhesive layer, but this method results in low dye transfer image density and the need for multiple transfers on transfer paper with low surface smoothness. There are problems such as a severe drop in density when printing.

Further, as an attempt to solve the first and second problems, Example 7f, JP-A-61-162395, discloses a technique for adjusting the amount of transfer of the heat-melting coloring material layer through an adhesive layer. , discloses a technique for using solid polyethylene glycol diester or wax as a thermal transfer recording medium.

However, according to this method, it is stated that it is possible to print with high dye transfer image density on transfer paper with low surface smoothness using low energy and multiple printings. In terms of technology, in view of the printing reliability described below, it is not possible to use anything other than thermal transfer recording media mainly made of carnauba wax.

According to the heat-sensitive transfer recording medium of this method, the dye transfer image lacks adhesion to the receiving paper with low surface smoothness, is hard, and is brittle. The statue may crack and fall off.

Regarding the problem of decreased resolution, carnauba wax is acceptable, but in other cases, including other known technologies, overall, the problem is that the pigment resolution of print durability is significantly decreased, and as a result, after printing A thermal transfer recording medium with high printing durability is desired.

That is, in recent years, thermal transfer recording media mainly made of known carnauba fuchs have been widely used.

In its use, carnauba wax is a natural plant-based wax, and there are problems with its supply amount, amount of resources, price, etc., and it can be replaced by carnauba wax with high printing performance (high quality) and the above-mentioned. There is a strong need for a new thermal transfer recording medium that can solve the reliability problem of dye transfer images.

The present invention enables low-energy printing, is rich in toughness and anti-blocking property, and is capable of producing high-density dye transfer images many times, and is also suitable for receiving paper with low surface smoothness. The object of the present invention is to provide a new thermal transfer recording medium that can be printed clearly and with high density and has extremely good adhesion durability of a dye transfer image.

[Means for Solving the Problems] As a result of intensive research, the present inventors have discovered that a heat-sensitive transfer recording medium having a heat-melting coloring material layer on a support directly or through an adhesive layer. A new styrene-ethylene-propylene-styrene block copolymer resin in which the hot-melt colorant layer has a polystyrene end block and an intermediate block has a crystalline ethylene-propylene rubber block, and the following compound group (hereinafter referred to as wax compound) [Wax compound group] Comprising one or more heat-melting substances selected from animal-based waxes, plant-based waxes, mineral-based waxes, petroleum-based waxes, synthetic hydrocarbon-based waxes, and modified waxes. The inventors have discovered that the above technical problem can be solved, and have arrived at the present invention.

In the thermal transfer recording medium of the present invention, one or more heat-melting coloring material layers are provided on a support directly or via an adhesive layer. In addition, when two or more heat-melting coloring material layers are formed, the upper layer may be provided with a low softening point composition or a low viscosity composition, or the intermediate layer may be provided with a low softening point composition or a low viscosity composition. A layer may be applied.

In the novel thermal transfer recording medium of the present invention, the intermediate block is preferably a novel styrene-ethylene-propylene-styrene block having a polystyrene content in the range of 5 to 60% by weight and consisting of a crystalline ethylene-propylene block. Use of a copolymer resin, more preferably, the intermediate block consists of a crystalline ethylene-propylene block, and the intermediate block contains at least 60% by weight.
The new styrene-ethylene-propylene-styrene block copolymer resin containing crystalline polyethylene can be used at the above high ratio.

More preferably, the novel styrene resin has a weight average molecular weight in the range of 2,000 to 200,000, a polystyrene content in the range of 5 to 60% by weight, and the intermediate block has a crystalline ethylene-propylene block. Ethylene-propylene-styrene block copolymer resins can be used.

Most preferably, the weight average molecular weight is in the range of 5,000 to 200,000, and the polystyrene content is in the range of 5 to 60% by weight.
and a novel styrene-ethylene-propylene-styrene block copolymer resin in which the intermediate block has a crystalline ethylene-propylene block is used in a thermal transfer recording medium at most 30% by weight or less. A thermal transfer recording medium is preferred.

Further, in the novel thermal transfer recording medium of the present invention, the wax compound group is a heat-melting substance selected from animal waxes, vegetable waxes, mineral waxes, petroleum waxes, synthetic hydrocarbon waxes, and modified waxes. One or more of the following are contained in the thermal transfer recording medium at least 70%
It is preferable to use an ethylene-vinyl acetate copolymer resin containing 28% by weight or less of vinyl acetate as an essential component, and a weight average molecular weight in the range of 400 to 30,000. , polyethylene glycol diester, ethyl acrylate is 35% by weight or less,
Styrene-ethylene-butylene consisting of ethylene-ethyl acrylate copolymer resin, aromatic tackifying resin, alicyclic tackifying resin, rosin ester tackifying resin, crystalline polyester resin, and amorphous intermediate block body. - One or more heat-melting resin substances (hereinafter referred to as resin substances) selected from styrene block copolymer resin, ethylene-butadiene-styrene block copolymer resin 111n, and styrene-isoprene-styrene block copolymer resin It is highly preferable for the new thermal transfer recording medium to use 10% by weight or less in combination in the new thermal transfer recording medium.

Furthermore, in the novel thermal transfer recording medium of the present invention, the elongation rate of the molded product of the thermal transfer recording medium alone is at least 10
% or more, and the melt viscosity of the thermal transfer recording medium alone must be in the range of 5 to 20.000 cps at 110'C, and furthermore, the softening point temperature of the thermal recording medium alone by the ring and ball method must be However, it has been found that it is particularly preferable to maintain the temperature within the range of 75°C to 130°C.

The novel styrene-ethylene-propylene-styrene block copolymer resin having a polystyrene terminal block and having a crystalline ethylene-propylene rubber block in the intermediate block used in the present invention is a conventionally known,
Styrene-ethylene-propylene having an amorphous intermediate rubber block, typified by hydrogenated resin of styrene-isopropylene-styrene block copolymer resin, etc.
Styrene block copolymer resins are essentially completely different.

That is, the intermediate ethylene-propylene rubber block chain portion of the resin is controlled and adjusted to have a high ethylene content sufficient to exhibit crystallinity under normal conditions, and the compatibility with the wax compound group is improved. This is an extremely improved new styrene-ethylene-propylene-styrene block copolymer resin.

Furthermore, styrene-ethylene-propylene-styrene block copolymer resin or styrene-ethylene-propylene copolymer resin having an amorphous intermediate block,
Either crystalline low-molecular or medium-molecular polyethylene, or crystalline ethylene-butene copolymer resin containing a high proportion of polyethylene, or crystalline ethylene-propylene copolymer resin containing a high proportion of polyethylene. As a result, the resin is modified and adjusted so that it has a high proportion of ethylene content, which is sufficient to exhibit crystallinity in the normal state, and the compatibility with the wax compound group is improved. Also meant is a novel styrene-ethylene-propylene-styrene block copolymer resin with extremely improved crystalline polyethylene-based chain polymers.

The novel styrene-ethylene-propylene-styrene block copolymer resin described in the present invention, which has the above-mentioned polystyrene end blocks and has a crystalline ethylene-propylene rubber block in the intermediate block, can be produced by, for example, ionic polymerization. After polystyrene polymerization, a high proportion of ethylene and a low proportion of propylene are further controlled and arranged as an intermediate block, and then polystyrene is subsequently polymerized or coupled with a known coupling compound, resulting in As an example of synthesis, a method for obtaining a styrene-ethylene-propylene-styrene block copolymer so that the intermediate rubber block finally exhibits crystallinity is given.

In addition, for example, a styrene-ethylene-propylene-styrene block copolymer having an amorphous intermediate rubber block, such as a conventionally known hydrogenated resin of styrene-isopropylene-styrene block copolymer resin, etc. Polymer resin or styrene-ethylene-propylene block copolymer resin having an amorphous rubber block, respectively, with crystalline low-molecular or medium-molecular polyethylene, or crystalline ethylene-butene with a high proportion of polyethylene. Copolymer resin or crystalline ethylene-propylene copolymer resin with a high proportion of polyethylene may be obtained by graft polymerization, and as a result, crystallinity can be exhibited under normal conditions. The polystyrene terminal block described in the present invention can be modified to obtain a resin obtained by modifying the crystalline polyethylene chain polymer so as to have a sufficiently high ratio of ethylene content. A new styrene-ethylene-
This is mentioned as a preferable synthesis example of a propylene-styrene block copolymer resin.

The crystallinity described in the present invention means that the intermediate rubber block body is
It exhibits behavior similar to the crystalline properties of low-density polyethylene, and exhibits melting heat absorption peaks in a differential scanning calorimeter, especially in the range from room temperature to about 120°C, preferably in the range of 20"C to 70°C. means a property observed as

Another aspect of the present invention can be achieved by using a new styrene-ethylene-propylene-styrene block copolymer resin having the polystyrene terminal block of the present invention and a crystalline ethylene-propylene rubber block in the intermediate block. The miscibility with the above-mentioned wax compound group compounds, which are components, is significantly improved, and as a result, the hardness of thermal transfer recording media in the prior art, which is the technical problem typified by solid wax compounds, is improved. The brittle properties are significantly improved (the effect of improving toughness without compromising rigidity)
.

In addition, when the heat-melting coloring material layer contains an ink pigment such as carbon black, pigment dispersion stability, thermal stability,
Effects such as excellent hue stability and weather resistance, and
Appropriate adhesion can be achieved with various supports such as colorant layers or plastic films, and stable, high-density transfer can be performed multiple times.

Furthermore, even in the case of transfer paper such as plain paper with low surface smoothness, it exhibits the effects of high density and high print quality, that is, excellent print adhesion and durability, sharpening of print resolution and dye The mechanical adhesion durability retention rate of the transferred image is greatly improved.

The wax compound group substance used in the present invention is a wax that is solid at room temperature, preferably a melting point of 40°C to 90°C.
Waxes having a temperature range of 0.degree. C. are preferable, and specifically, the waxes listed below are typical.

That is, the animal wax used in the present invention is
Examples include spermaceti wax, wool wax, insect wax, shellac wax, and beeswax. Examples of vegetable waxes include carnauba wax, wood wax, auricular wax, esparto wax, candelilla wax, and mineral waxes. Examples of the wax include montan wax, osikelite, and ceresin, and examples of the petroleum wax include paraffin wax, microcrystalline wax, ester wax, petrolatum, and polyethylene gelcol diester wax.

Examples of synthetic hydrocarbon waxes include Fischer-Tropsch wax, polyethylene wax, low molecular weight polypropylene wax, low molecular weight polyethylene wax and derivatives thereof, and examples of modified waxes include oxidized wax and montan wax. Examples include derivatives, paraffin, and microcrystalline wax derivatives, and one type or a combination of two or more types may be used.

In the present invention, hydrogenated waxes such as castor wax and opal wax, which do not belong to the above wax compound group, may be used in combination.

The present invention also uses the following resin materials, such as ethylene-vinyl acetate copolymer resin with a vinyl acetate content of 28% by weight or less, polyethylene glycol diester, and ethyl acrylate with a weight average molecular weight in the range of 400 to 30,000. 35% by weight or less of ethylene-ethyl acrylate copolymer resin, (hydrogenated) terpene resin, (hydrogenated) terpene phenol resin, (hydrogenated) C9 petroleum resin, (hydrogenated) C5-C
9 Copolymerized petroleum resins, low-molecular polystyrene resins, styrene-modified petroleum resins, aromatic tackifying resins represented by low-molecular α-methylstyrene resins, (hydrogenated) dicyclopentadiene petroleum resins, etc. A styrene-ethylene-butylene-styrene block consisting of an alicyclic tackifying resin represented by a rosin ester or its derivative, a crystalline polyester resin, and an amorphous intermediate rubber block. One or more selected from copolymer resins, styrene-butadiene-styrene block copolymer resins, styrene-isoprene-styrene block copolymer resins, polyethylene, polypropylene, etc., in a new thermal transfer recording medium, When used within 10% by weight at most, the effects of appropriate adhesive properties, appropriate viscosity modification, adjustment of softening temperature, high resolution of low energy printing, and improvement of the strength of printed transferred images are exhibited. They may be used together for such purposes.

In the present invention, a novel styrene-ethylene-propylene-styrene block copolymer having the above polystyrene terminal block in the heat-melting coloring material layer and a crystalline ethylene-propylene rubber block in the intermediate rubber block is used. There is no particular limitation on the means for incorporating the resin and the above-mentioned wax compounds, and for boat fishing, they may be obtained by melting and mixing.

In cases where some of the wax compounds show immiscibility,
For example, it may be used by vigorously stirring and uniformly dispersed, or it is also possible to use a solvent to form a compatible state and then remove the solvent to form a finely dispersed state.

In the present invention, there are no particular limitations on the method of forming the heat-melting coloring material layer in the form of an ink, and the method includes the above-mentioned polystyrene terminal block and a crystalline ethylene-propylene rubber block as an intermediate block. A method of simultaneously dispersing a novel styrene-ethylene-propylene-styrene block copolymer resin and the above-mentioned wax compound group with a colorant (dye or pigment), optionally containing a resin substance, or the present invention Either one of these components and the coloring agent may be separately dispersed in advance.

That is, in the present invention, the colorant dispersion is a novel styrene-propylene rubber block having the above polystyrene end blocks and a crystalline ethylene-propylene rubber block as an intermediate block.
It may be done before or after dispersing the ethylene-propylene-styrene block copolymer resin.

The colorant used in the heat-melting color material layer of the present invention may be appropriately selected from various pigments, and particularly preferably direct dyes, acid dyes, basic dyes, disperse dyes, and oil-soluble dyes. (including metal oil-soluble dyes), and indoaniline dyes, azomethine dyes, and the like can also be preferably used.

Furthermore, as the pigment used in the color material layer of the present invention, any pigment that can basically be transferred (transferred) as well as a heat-melting substance may be used. It may also be a pigment.

Specific examples of the coloring agent used in the heat-melting coloring material layer of the present invention include the following.

That is, examples of yellow pigments include PS Yellow GO (manufactured by Mitsui Toatsu Chemicals), PS Yellow SK (manufactured by Mitsui Toatsu Chemicals), Kayalon Polyester Light Yellow 5G-3 (manufactured by Mitsui Toatsu Chemicals), and
Examples of red pigments include Oil Yellow 5-7 (white clay), Eisenspiron Yellow GRH Special (Hodogaya), Sumiplast Yellow FG (resident), Eisensubiron Yellow GRH (Hodogaya), etc. P
S Red G (Mitsui Toatsu Chemical Co., Ltd. product), MS Red VP (Mitsui Toatsu Chemical Co., Ltd. product), Diaceritone Fast Red R (
Mitsubishi Kasei), Sumipura Tread FB (resident), Sumipura Tread HFG (resident), Kayalon Polyester Pink RCL-E (Northeast Japan), Eisenspiron Red GHR Special (Hodogaya), etc. can be used.

As the blue pigment, for example, Miketon Polyester Blue FBL Conc (Mitsui Toatsu Chemical Co., Ltd. product), PET Blue #
2,000 (Mitsui Toatsu Chemical Co., Ltd. product), PS Blue BN (
Mitsui Toatsu Chemical Co., Ltd.), Diaceriton Fast Brilliant Blue (Mitsubishi Kasei), Dianic Sprue EB-
E (Mitsubishi Kasei), Kayalon Polyester Flu Northeast), Sumiplast Blue 3R (Resident), Sumiplast Blue G (Resident), etc. can be used.

In addition, as a yellow colored pigment, for example, Hansa Yellow 3
Examples of red coloring pigments include Brilliant Carmine FB-Pure (deuterochrome), Brilliant Carmine 6B (deuterochrome), Alizarin Lake, etc., and examples of blue coloring pigments include, for example, Cerulean Blue Mikabrin. Tocyanin Blue〇N-0
Typical examples of black colored pigments include carbon black and oil black, and carbon black is the most preferred coloring agent in the present invention.

In addition, the colorant used in the heat-melting color material layer of the present invention may be subjected to a treatment using a known method such as microencapsulation to improve weather resistance, wetting characteristics, transferability, dispersibility, etc. of the colorant. It is also preferable to adopt and use it for the purpose of improvement.

Although the composition ratio of the heat-melting coloring material layer of the present invention is not limited,
Based on 100 parts by weight of the solid content of the heat-melting coloring material layer, the heat-melting substance is 5 to 80 parts by weight, preferably 10 to 60 parts by weight, and the coloring material is 5 to 50 parts, preferably 10 to 40 parts. It is preferable to use within this range.

In addition to the above-mentioned components, various additives may be added to the heat-melting coloring material layer of the present invention, such as vegetable oils such as castor oil, linseed oil, and olive oil, animal oils such as whale oil, mineral oils, Liquid polybutene, liquid hydrogenated polyisoprene,
Synthetic oils such as paraffin oil and naphthenic oil, polyalkylene glycol, fluorine oil, silicone oil, etc. 'ft conductive fine powders such as oil, graphite, graphite, and metal fine powders, thermally decomposable blowing agents such as inorganic compounds such as bicarbonates, carbonates, and nitrites, or organic compounds such as sulfonyl hydrazides, thermally expandable fine particles, Polymerization inhibitors, anti-aging agents, ultraviolet stabilizers (sound-light stabilizers), ultraviolet absorbers (sound-light absorbers), dispersion stabilizers, viscosity modifiers (including titanium-containing property improvers), surfactants, high-boiling point solvents It is preferable to use various additives such as these depending on the purpose.

In the heat-sensitive transfer recording medium of the present invention, a suitable technique for applying the heat-melting coloring material layer onto the support may be any known technique, such as true melt coating or coating of the composition. There are coating techniques such as solvent coating using a coating liquid in which silica is dissolved in a solvent, and emulsion coating by dispersing it in water.

That is, as the coating method for forming the heat-melting coloring material layer of the present invention, known techniques such as a reverse roll coater method, an extrusion coater method, a gravure coater method, a wire bar coating method, etc. can be employed.

Further, the thickness of the coating film for forming the heat-melting coloring material layer of the present invention is not limited, and in terms of -m, it is preferably 20 microns or less, preferably 10 microns or less, and more preferably 5 microns or less.

In addition, in the present invention, an adhesive layer may be applied in advance to the surface of the support in order to improve the durability of the thermal ribbon product and to adjust the transfer rate during multiple transfers, such as polyvinyl butyral resin, epoxy Among thermoplastic resins or thermosetting resins represented by resins, polyester resins, ethylene-vinyl acetate resins, ethylene-ethyl acrylate resins, vinyl chloride resins, polyacrylate resins, polyurethane resins, styrene-based bronze copolymer resins, etc. , one type or a combination of two or more types can be used as an adhesive layer,
It is preferable to use the novel thermal transfer recording medium of the present invention, which does not contain a dye component and is adjusted to a relatively high viscosity, as an adhesive layer.

The thickness of the adhesive layer is not particularly limited, but is usually 0.1 to 5 microns, preferably 0.3 to 2 microns.

In the present invention, the hot-melt coloring material layer may be laminated on the support in one or more layers directly or via an adhesive layer, or by applying an intermediate layer, For example, when applying one heat-melting coloring material layer using the coating technique described above, care must be taken not to completely mix the two types of new thermal transfer recording media of the present invention, which have different properties, with each other. With two hot melters and an extrusion composite nozzle, it can be coated twice at the same time, apparently in one layer,
The novel thermal transfer recording medium of the present invention may be obtained by a coating method so as to have substantially two layers, and when two or more layers are coated, the upper layer is substantially the novel thermal transfer recording medium of the present invention and the novel thermal transfer recording medium of the present invention is the lower layer. By making the actual softening point a little lower than that of the medium or by making the melt viscosity a little lower, it is possible to bond the novel thermal transfer recording medium of the present invention, which has a relatively high viscosity, without any problems. One layer or two layers using the novel thermal transfer recording medium of the present invention are used as an agent layer or an intermediate layer.
It is preferable to provide more than one layer of the heat-melting coloring material obtained in the present invention.

As the support for use in the thermal transfer recording medium of the present invention, a support that is rich in thermal rigidity (heat-resistant strength), dimensional stability, and surface smoothness may be selected and used.

Specifically, as heat resistance strength, it has both toughness and dimensional stability that do not soften or plasticize due to the heating temperature of a heat source such as a thermal head, and the surface smoothness is a color containing a heat-fusible substance on the support. It is desirable that the material layer has sufficient smoothness to exhibit a good thermal transfer rate (high print density and high resolution).

Examples of such materials include papers such as plain paper, condenser paper, laminated paper, coated paper, polyethylene, polyethylene terephthalate, polyester, polystyrene, polypropylene, polyamide, polyimide, polyetherketone, polyethersulfone, polycarbonate, nonyl, Metal-paper composites such as resin films such as polyphenylsulfone, resin-resin film composites, metal films such as aluminum foil and stainless steel foil, metal foil-resin film composites such as aluminum, paper-aluminum metal foil, etc. A paper-metal foil-resin film composite, etc. can be suitably used. The thickness of the support is generally 60μ or less, preferably 30μ or less, and particularly preferably 2μ to 20μ in order to obtain good thermal conductivity.

Further, the support used in the thermal transfer recording medium of the present invention is
There are no particular restrictions on the structure of the back side of the support, and it is arbitrary, and any number of supports may be provided with a backing layer such as an anti-blocking layer or an anti-sticking layer. .

[Examples] Examples of the present invention are shown below, but the invention is not particularly limited, and the terms % and parts shown in the examples below mean % by weight and parts by weight, respectively.

Example 1 A wire bar was used to coat a polyethylene terephthalate film support with a thickness of 3.5 μm to a dry film thickness of 1.5 μm.
An adhesive layer was obtained by applying an ethylene-ethyl acrylate resin (NUC6070 manufactured by Nippon Unica Co., Ltd.) solution to a thickness of 0 microns, and after drying, the following colorant layer coating composition was applied using a hot melt coating method. and the film thickness is 10
A sample A of the thermal transfer recording medium of the present invention (a ribbon-shaped test piece with a width of 8 mm) was obtained by directly coating the sample so as to have a width of .mu.m.

Further, the colorant layer alone of thermal transfer recording medium A was found to have appropriate hardness and toughness, and had an elongation property of about 20% or more.

Hydrogenated styrene-ethylene-propylene-styrene block copolymer resin containing about 13% polystyrene (Califlex TR-1107 manufactured by Shell Chemical Co.), which has an amorphous ethylene-propylene rubber block in the intermediate rubber block. 65 parts of hydrogenated resin) and 65 parts of crystalline low molecular weight high-density polyethylene (Mitsui Petrochemicals, Mitsui Hiwax 20 with a molecular weight of 2,000 determined by the viscosity method)
Using a small Ni-Goo, 35 parts of 0P) were melt-kneaded at a melting temperature of 135°C in a nitrogen stream, and 0.6 parts of a peroxide catalyst (dicumyl peroxide) was added to the system in three parts. The novel styrene-ethylene-propylene-styrene block composition of the present invention, in which a crystalline polyethylene block is arranged as a result of graft polymerization modification of a mostly crystalline low-molecular-weight polyethylene resin, is introduced every hour. Polymer resin: 17 parts paraffin wax (melting point 64°C) Nihon Seirosha product HNP-3
: 5 parts oxidized wax (melting point 75°C) Nippon Seirosha product NPS'-
9210: 10 parts Microcrystalline wax (melting point 88°C) Nippon Seirosha product Hi-Mic-3090: 52.8 parts Carbon black (paint grade) Mitsubishi Chemical Industries product MA100 15 parts Penataerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl)propionate] Anti-aging agent
: 0.2 parts This thermal transfer recording medium sample A was coated with an applied energy of 0.7 using a thermal printer (a device with a built-in thermal head with a heating element density of 16 Dot/mm).
mj/Dot, commercially available high-quality paper (Beck smoothness 1)
00sec) and copy paper (Beck smoothness 30sec)
The recording (printing) test was repeated twice on each plain paper.

In addition, using the gi for which printing was completed in Example 1 (the gi printed out in Example 1 and provided with the printed recording transfer image),
Table 1 shows the results of two 360° bending tests and a nail peeling test.

Example 2 In Example 1, a new styrene-ethylene-butylene-styrene block copolymer resin half mold containing crystalline polyethylene was replaced with a rubber block using amorphous ethylene-propylene rubber. styrene-ethylene-propylene block copolymer resin containing 37% polystyrene (Krayton G, a product of Shell Chemical Co.)
-1701
000 Mitsui Hiwax 400P) was obtained by graft polymerization modification in a nitrogen stream using a peroxide catalyst (benzoyl peroxide), most of which was crystalline in the side chains. A thermal transfer recording medium sample of the present invention (
A ribbon-shaped test piece) B with a width of 8 mm was obtained.

The coloring material layer alone of thermal transfer recording medium B was found to have appropriate hardness and toughness, and had an elongation property of about 10% or more.

Using this thermal transfer recording medium sample B, a printing test was conducted using a thermal printer in the same manner as in Example 1, and two 360° printing tests were conducted using the paper on which printing was completed in Example 2.
Table 1 shows the results of the bending test and nail peeling test.
Described in .

Comparative Example 1 In Example 1, instead of the new styrene-ethylene-butylene-styrene block copolymer resin containing crystalline polyethylene, ethylene-vinyl acetate copolymer (Evaflex #410 manufactured by Mitsui Polychemical Co., Ltd.) was used. ), and in the same manner except for that, a comparative thermal transfer recording medium sample (8 mm wide ribbon-shaped specimen) C was obtained, in which the coloring material layer alone had no elongation and was hard and brittle. .

Using this thermal transfer recording medium sample C, a printing test was conducted with a thermal printer in the same manner as in Example 1, and in Comparative Example 1.
Table 1 shows the results of two 360° bending tests and a nail peeling test using the paper on which printing was completed.

Table 1 Aσ bending ◎:: Almost no cracking or peeling was observed in the transferred image (reflection density retention rate of 90% or more).

O: Very slight cracking or peeling of the printed transfer image was observed.
(Reflection density retention rate of 80% or more).

×: Severe cracking and peeling of the printed transfer image were observed. (
reflection density retention rate of 70% or less).

Nail peeling ◎: Hardly any fading was observed on the middle side of the printed transfer image or on the surface of the printed image (Bθmπ Baro) ■Temple rate 90%
(recorded).

○: Extremely biased, cracking, peeling, and fading of the printed transfer image were observed.

(Reflection density retention rate of 80% or more).

×: Severely printed transferred image showed cracking, peeling, and fading.

(Drinking θkebe U Jotōji rate 70% IfF).

As is clear from the results in Table 1 above, sample A of the present invention
, B, not only high-quality paper with a Beck smoothness of 100 seconds, but also copy paper with a Beck smoothness of 30 seconds.
There was only a slight decrease in the resolution density of the printed transfer image from the first to the second time, and high density transfer was possible with low energy printing, but in comparison sample C, the density from the first to the second time was The drop was large, indicating that there was a problem.

In addition, the results of the mechanical durability of the printed transfer images showed that Samples A and B of the present invention had excellent towability and adhesion properties of the transferred print bodies, resulting in high printing durability and reliability. , comparative letter F
In 4C, since the transfer print body was inherently hard and brittle, the reliability of print durability was extremely low.

Example 3 In Example 1, heat-sensitive transfer recording medium samples were obtained by changing the damage resistance of the coloring material layer (applied as a dispersion using Daysilver) as follows.

New styrene-ethylene-propylene-styrene block copolymer resin with crystalline polyethylene shown in Example 1: 10 parts ethylene-ethyl acrylate copolymer (containing 17% ethyl acrylate) (Eva, a product of Mitsui Polychemical Co., Ltd.) Flex-EEA, A-7
07): 5 parts oxidized wax (Hiki Seirosha product NPS9125) 210
Part carnauba wax (melting point 83°C): 10 parts Microcrystalline wax (melting point 84°C) Nippon Seirosha product Hi-
Mtc-1080 = 50 parts Carbon black (paint grade) Mitsubishi Chemical Industries product MA200: IS part Regarding this thermal transfer recording medium sample, recording ( Printing) The test was repeated twice.

Table 2 shows the results of two 360° bending tests and a nail peeling test using the printed paper.

Further, in Example 3 above, ethylene-ethyl acrylate copolymer was used, and in E of Table 2, ethylene-vinyl acetate (Evaflex EVA, manufactured by Mitsui Polychemical Co., Ltd., #410) was used.
), F in Table 2 shows amorphous styrene-ethylene-butylene-styrene block copolymer resin (Asahi Kasei H-
1052) and G in Table 2 uses oxidized wax (Japanese wax).
NPS9125) and H in Table 2 were changed to carnauba wax, respectively, to obtain H from thermal transfer recording medium sample E in the same manner.

Using these thermal transfer recording medium samples E to H, Example 1
In the same manner as above, a recording (printing) test was repeated twice on a copy (Beck smoothness: 30 seconds).

Table 2 shows the results of two 360° bending tests and a nail peeling test using the printed paper.

In addition, each sample was tested for blocking property (a film-like sample with a thickness of 5 μm was stacked with a polyethylene terephthalate film, left under a load of 15 gr/cm 2 at 40°C/95% RH for 1 day, then taken out and peeled off). The results of the blocking resistance test method (blocking resistance test method) are also listed in Table 2.

Table-2 degree retention rate of 85% or more).

○: Very slight cracking or turning of the printed transfer image is observed, f,
:, (Reflection density retention rate 70% or more).

1 ◎: The printed transfer image is cracked or 2 In (I)
, almost no fading was observed (reflection density retention rate of 85% or more).

0: Very slight print transfer (elephant 1 reya kaya! dancing, fading was observed.

(Reflection density retention rate of 70% or more).

[Printing test results] Very good: The printing is extremely clear, and the optical reflection density is 1.
．． 0 or more, and the second concentration decrease is within ±20%.

Good: The print is clear, the optical reflection m<0.9 or more, and the second density decrease is ±30% or more. Even with the test specimen provided with a material layer, its thermal transfer recording properties are high density and can be printed many times, excellent blocking resistance, and the mechanical durability of the printed transferred image after printing is the lowest. However, it can be seen that the concentration retention rate is over 70%, which is particularly excellent.

Also, during testing with a thermal printer, no problems were encountered.

Example 4 A heat-melting coloring material using the same novel thermal transfer recording medium of the present invention as used in Example 1 was placed on an aluminum foil-paper composite support film with a thickness of 3.5 microns. Directly as the first layer, a 4 μm thick film was laminated using the true melt coating method, and then amorphous ethylene was applied to the rubber prongs.
Styrene-ethylene-propylene rubber block, containing 37% polystyrene, weight average molecular weight 30,000,
For 100 parts of propylene block copolymer resin, crystalline low density low molecular weight polyethylene (Mitsui Petrochemicals,
35 parts of Mitsui Hiwax 320P (with a molecular weight of 13,000, determined by the viscosity method) was graft polymerized and modified in a nitrogen stream using a peroxide catalyst (benzoyl peroxide). 20 parts of a new styrene-ethylene-butylene-styrene block copolymer resin in which crystalline polystyrene is arranged in the side chain, and microcrystalline wax (softening point 84°C) Nippon Seirosha product HiMic-
60 parts of 1080 and oxidized wax (freezing point 63”C)
A heat-melting coloring material using the new thermal transfer recording medium of the present invention, consisting of 10 parts of Nippon Seirosha product NPS9125 and 10 parts of carbon blank, was laminated to a film thickness of 8 μm by hot melt coating method as the second layer. (Total 12
A novel thermal transfer recording medium sample (8 mm wide ribbon-shaped test piece) K of the present invention was obtained, which consisted of the obtained two layers.

Using this thermal transfer recording medium sample K, a recording (printing) test was repeated twice on copy paper (Beck smoothness: 30 sec) using the same material as in the example.

As a result, the reflection density was 1.17 at the first time and 0 at the second time.
．． I got 89.

In addition, the printed paper was subjected to two 360° bending tests and a nail peeling test, and the results were good with almost no fading or peeling of the characters.

In addition, a blocking property test (a film sample with a thickness of 12 μm was stacked with an aluminum foil-Gi composite support film,
Under a load of 15gr/cm2, at 40℃/95%RH,
After leaving it for one day, it was taken out and peeled off (blocking resistance test method).

There were no abnormalities in the results, and no similar inconvenient problems occurred during testing with a thermal printer.

From this result, it was found that the novel thermal transfer recording medium of the present invention may be formed by forming two coloring material layers directly on the support.

[Effects of the Invention] According to the present invention, the heat-sensitive coloring material layer has excellent blocking resistance and toughness, and enables low-energy printing, with relatively little decrease in print density even after several uses, and provides clear and sharp printing. Demonstrates high resolution.

In addition, when printing on plain paper with poor surface smoothness, uneven film, etc., in addition to the above performance, the mechanical durability of the transferred printed material is extremely excellent, which was not achieved with conventional products. It is possible to obtain a transfer printed body having toughness and adhesiveness that fully corresponds to the toughness of the transfer paper, which is a film having roughness or irregularities.

Furthermore, it is possible to obtain the effect of reducing color fading, fading over time, and low density of the transferred printed material.

Claims (1)

[Claims] 1. In a heat-sensitive transfer recording medium having a heat-melt coloring material layer directly or via an adhesive layer on a support, the heat-melting coloring material layer has a polystyrene end block. , a new styrene-ethylene-propylene-styrene block copolymer resin having a crystalline ethylene-propylene rubber block in the intermediate block, and one or two selected from the following compound group.
A novel heat-sensitive transfer recording medium characterized by containing more than one heat-melting substance. Compound Group: Animal-based waxes; Plant-based waxes; Mineral-based waxes; Petroleum-based waxes; The novel thermal transfer recording medium according to claim 1, characterized in that a styrene-ethylene-propylene-styrene block copolymer resin is used. 3. The intermediate block consists of a crystalline ethylene-propylene block, and the intermediate block has at least 6
3. The novel thermal transfer recording medium according to claim 2, characterized in that a novel styrene-ethylene-propylene-styrene block copolymer resin having a high proportion of crystalline polyethylene of 0% by weight or more is used. 4. A novel styrene-ethylene-propylene having a weight average molecular weight in the range of 2,000 to 200,000, a polystyrene content in the range of 5 to 60% by weight, and an intermediate block having a crystalline ethylene-propylene block. 4. The novel thermal transfer recording medium according to claim 3, characterized in that a styrene block copolymer resin is used. 5. A novel styrene-ethylene-propylene having a weight average molecular weight in the range of 2,000 to 200,000, a polystyrene content in the range of 5 to 60% by weight, and an intermediate block having a crystalline ethylene-propylene block. At most 30% of the styrene block copolymer resin is added to the thermal transfer recording medium.
5. The novel thermal transfer recording medium according to claim 4, characterized in that the amount thereof is within % by weight. 6. At least one or more heat-melting substances selected from animal waxes, vegetable waxes, mineral waxes, petroleum waxes, synthetic hydrocarbon waxes, and modified waxes are added to the thermal transfer recording medium. Claims 1 to 5 characterized in that the composition contains 70% by weight or more as an essential component.
Any of the novel thermal transfer recording media described above. 7. The novel thermal transfer recording medium according to any one of claims 1 to 6, characterized in that the molded product of the thermal transfer recording medium alone has an elongation rate of at least 10% or more. 8. A novel thermal transfer recording medium according to any one of claims 1 to 7, characterized in that the thermal transfer recording medium alone has a melt viscosity in the range of 5 to 20,000 cps at 110°C. . 9. The novel thermal transfer recording medium according to any one of claims 1 to 8, characterized in that the softening point temperature of the thermal transfer recording medium alone, measured by the ring and ball method, is in the range of 75°C to 130°C. 10. Ethylene-vinyl acetate copolymer resin with a vinyl acetate content of 28% by weight or less, polyethylene glycol diester with a weight average molecular weight in the range of 400 to 30,000, and ethylene-ethyl acrylate copolymer with a ethyl acrylate content of 35% by weight or less resin, aromatic tackifier resin, alicyclic tackifier resin, rosin ester tackifier resin, crystalline polyester resin, styrene-ethylene-butylene-styrene block copolymer resin consisting of an amorphous intermediate block body, Selected from styrene-butadiene-styrene block copolymer resin and styrene-isoprene-styrene block copolymer resin, which has a softening point of 13 when measured by ring and ball method.
Any one of claims 1 to 9, characterized in that the heat-sensitive transfer recording medium contains at most 10% by weight of one or more heat-melting resin substances exhibiting a temperature of 0°C or lower. A new thermal transfer recording medium.