JPH01299084A - Thermal transfer recording material - Google Patents

Abstract

PURPOSE:To form a good transfer image even to plain paper low in surface smoothness without lowering resolving power, by forming a release layer having protruding parts formed thereto at the places corresponding to fine particles and a heat-meltable colorant layer applied to said release layer so as not only to become thicker than the protruding parts but also to form a flat surface. CONSTITUTION:A release layer 3 is constituted of a film 3a consisting of a surfactant and a film forming material covering the surface of a base material and fine particles 3b dispersed in a state covered with said film 3a and protruding parts are formed to said layer 3 at the places corresponding to the fine particles. A more pref. average particle size of the fine particles is within a range of 2-5mum. When the surfactant being one component is below a lower limit value, there is possibility such that the release function of the film to a heat-meltable colorant layer is lowered and, when said surfactant exceeds an upper limit value, the mechanical strength of the film is lowered and the fine particles coated with the film are detached. The more pref. composition ratio of the surfactant and the film forming material is within a range of 10:90-60:40. The heat-meltable colorant layer 4 consists of an org. substance melting at predetermined temp. and a colorant and is applied to the release layer so as to be thicker than the protruding parts of the release layer and to form a flat surface.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a thermal transfer recording material.

(Prior art) In order to transfer a thermal transfer recording material to a transfer material, the thermal transfer recording material and the transfer material are brought into close contact with each other on a thermal head under a certain pressure, and a pressure is applied from the thermal head. A method is employed in which the ink layer (heat-melting color material layer) of the heat-sensitive transfer recording material is melted by thermal energy and transferred onto the transfer material. At this time, if the thermal transfer recording material and the material to be transferred are not in sufficient contact with each other, transfer will not be performed at the portions with poor adhesion. For this reason, in order to sufficiently improve adhesion, it is necessary to use a smooth material with few irregularities as the transfer material.

However, since the paper generally used as the transfer material is made of vegetable fibers, it has severe irregularities and is difficult to smooth by itself.

For this reason, the paper used as the transfer material is specially treated to improve its smoothness. However, this specially treated paper has problems such as a unique gloss on the surface and a poor texture. For this reason, the paper used in daily life (
There is a demand for a thermal transfer recording material that can perform good transfer even to bond paper (plain paper) and bond paper with a Bekk smoothness of about several seconds to several tens of seconds.

In response to the above-mentioned demands, conventional heat-sensitive transfer recording materials capable of recording on plain paper include (1) a material containing a thermally decomposable foaming agent in the ink layer disclosed in JP-A-59-201893; JP-A No. 59-201894, in which the ink layer contains a particulate filler containing an easily volatile organic liquid;
4, the ink layer is separated into upper and lower layers, and the lower layer contains a high boiling point solvent; Attempts have been made to improve the transfer efficiency by using inks containing expandable substances, etc., in which the ink layer changes to correspond to the unevenness of the paper due to thermal energy during transfer.

However, these thermal transfer recording materials have a complicated film forming process and are difficult to manufacture, and also have problems with stability such as solvent volatilization.

On the other hand, a structure in which a release layer is provided on a sheet-like base material and a coloring material layer is provided on the release layer (for example, Japanese Patent Laid-Open No. 80-234889
The structure disclosed in the above publication (in which a layer of heat-melting material containing a surfactant is provided on a layer of heat-melting color material) enables good transfer from paper with high smoothness to paper with low smoothness. A heat-sensitive recording material has been proposed. However, in such heat-sensitive transfer recording materials, since the heat-melting coloring material layer contains a large amount of low-molecular-weight wax components, when a high-melting point heat-melting substance is coated on top of the heat-melting coloring material layer, the lower coloring material layer causes re-melting or re-melting, making it difficult to stably produce heat-sensitive transfer recording materials.

Furthermore, JP-A-59-171891 discloses an invention relating to a pressure-sensitive and heat-sensitive carbon copying paper in which a hot-melt carbon layer is provided on a base material via a hot-melt type peeling layer made of a surfactant and waxes. has been done. but,
Since such copying paper contains 30 to 50% by weight of wax in the release layer, there is a problem in that the carbon layer containing wax gets mixed into the release layer during the production of the recording material.

(Problems to be Solved by the Invention) The present invention has been made in order to solve the above-mentioned conventional problems. The object of the present invention is to provide a heat-sensitive transfer recording material capable of forming.

[Structure of the Invention] (Means for Solving the Problems) The thermal transfer recording material of the present invention includes (a) a sheet-like base material, and (b) provided on the base material and covering the surface of the base material. (C) a release layer composed of a coating made of a surfactant and a film-forming material and flat fine particles dispersed while being covered by the coating, and in which convex portions are formed at locations corresponding to the fine particles; A heat-melting coloring material layer made of an organic substance and a coloring agent that melts at a predetermined temperature and is coated on the release layer so as to be thicker than the convex portion of the release layer and have a flat surface. This is a characteristic feature.

The basic structure of the thermal transfer recording material according to the present invention will be explained below with reference to the conceptual diagram shown in FIG.

1 in the figure is a sheet-like base material, and the back surface of this base material 1 is coated with a back coat layer 2 for imparting heat-resistant slipperiness. The surface of the base material 1 is coated with a release layer 3. This peeling layer 3 consists of a coating 3a made of a surfactant and a film-forming material that covers the surface of the base material 1, and fine particles 3b having an average particle size of 1 to 6 μm dispersed while being covered with the coating 3a.
It has a structure in which a convex portion is formed at a location corresponding to the fine particle powder 3b. Further, the peeling layer 3 is coated with a heat-melting coloring material layer 4 made of an organic substance and a coloring agent that melts at a predetermined temperature and is thicker than the convex portions of the peeling layer 3 so that its surface is flat. The convex portions of the peeling layer 3 are buried in the heat-melting coloring material layer 4 due to the coating with the heat-melting coloring material layer 4 .

Next, (a) a sheet-like base material, (b) a peeling layer, and (c) a heat-melting coloring material layer that constitute the thermal transfer recording material of the present invention will be explained in detail.

(a) Sheet-like base material Examples of this base material include various plastic sheets,
Examples include plastic laminate sheets.

(b) Release layer The release layer consists of a film made of a surfactant and a film-forming material that covers the surface of the base material, and fine particles (preferably with an average particle size of 1 to 8 μm) that are dispersed while being covered with this film. It has a structure in which convex portions are formed at locations corresponding to the fine particles.

The fine particles may be either organic or inorganic. As the organic substance, for example, a thermosetting resin or a thermoplastic resin can be used, and when forming fine particles with a thermoplastic resin, it is desirable to select one having a glass transition temperature or heat distortion temperature of 80° C. or higher. Specific examples of such organic substances include silicone resin fine particles, acrylic esters such as isopropyl acrylate and isobutyl acrylate, methacrylic esters such as methyl methacrylate and isobutyl methacrylate, and at least one monomer such as styrene and its derivatives. Resin beads obtained by suspension polymerization of seeds, or resin beads obtained by suspension polymerization by adding divinylbenzene or the like to these monomers for three-dimensional crosslinking are suitable. Examples of inorganic materials include silica, alumina, talc, graphite, iron oxide, triiron tetroxide, and shirasu balloon.

The reason why the average particle size of the fine particles is limited is that if the average particle size is less than 1 μm, the height of the convex portions formed by the fine particles on the release layer will be reduced, and if the exfoliated particle size exceeds 6 μm, heat will be generated. The anchoring effect of the protrusions on the meltable coloring material layer becomes too large, impairing transferability, and the heat-melting coloring material layer corresponding to the protrusions to be transferred becomes thinner, resulting in poor transfer by the coloring material layer. This is because the continuity of More preferably, the average particle size of the fine particles is in the range of 2 to 5 μm. Further, it is desirable to use fine particles having a narrow particle size distribution with few coarse particles within the above particle size range.

If the above-mentioned fine particles are present in the peeled M layer in close packing, not only will the anchoring effect of the convex portions formed by the fine particles on the heat-fusible coloring material layer be impaired, but also the thermal energy applied by a heat generating element such as a thermal head will be lost. is not sufficiently transferred to the heat-fusible coloring material layer, which causes a decrease in transfer sensitivity. For this reason,
From the viewpoint of uniformly existing the convex portions in the release layer, the fine particles for forming the convex portions in the release layer are applied individually or as mutually independent particles or particle groups of 20 per 10,000 μm2 on the sheet-like substrate. It is desirable that the number of these particles be present at a ratio of ~2,000 pieces. As a means for dispersing such fine particles onto a base material, for example, a surfactant and a film forming material, which is a coating material containing fine particles, are placed on a sheet-like base material such that the fine particles are contained in the release layer in an amount of 10 to 60% by volume. A method may be adopted in which the coating is applied to a thickness of 0.19/m2 to 29/m2.

The surfactant that is one of the components of the coating is preferably one that is uniformly dispersed in the coating and enhances releasability to the heat-melting coloring material layer. Among such surfactants, examples of surfactants that are highly soluble in water include alkyl sulfates, alkylbenzene sulfonates, fatty acid salts, alkylnaphthalene sulfonates, dialkyl sulfosuccinates, alkyl phosphate ester salts, and naphthalene sulfonate formalin. Examples include condensates, polyoxyethylene alkyl sulfate salts, alkylamine salts, and quaternary ammonium salts. Examples of surfactants soluble in organic solvents include polyoxyethylene alkyl ether, polyoxyethylene alkylphenol ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylamine, and glycerin. fatty acid ester,
Examples include oxyethylene oxypropylene block polymers.

The film-forming material, which is the other component of the above-mentioned film, may be of any type as long as it has excellent film-forming properties. Among such film-forming materials, examples of water-soluble film-forming materials include polyvinyl alcohol, polyvinylpyrrolidone, gelatin,
Casein, gum arabic, carboxymethyl cellulose (CMC), etc. are suitable. Examples of film-forming materials soluble in organic solvents include acrylic esters such as methyl acrylate and isobutyl acrylate; methacrylic acids such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, and isobutyl methacrylate. Ester; Vinyl esters such as vinyl acetate and vinyl propionate; Vinyl chlorides such as vinyl chloride, vinyl fluoride, vinylidene chloride, vinylidene fluoride, and vinylidene bromide; Homopolymers made of monomers such as styrene and its derivatives , copolymers consisting of these monomers, or thermoplastic resins and epoxy compounds obtained by condensation polymerization of polycarbonate, polyester carbonate, polyamide, polyester, etc.
Thermosetting resins such as imide compounds, phenol resins, and melamine resins are suitable. Note that it is preferable that these film-forming materials do not melt and peel off from the sheet-like base material due to thermal energy during transfer.

The composition ratio of the surfactant and the film forming material constituting the film is preferably in the range of 1:100 to 80-220. The reason for this is that if the content of the surfactant, which is one of the components, is less than the lower limit value, there is a risk that the peeling function of the film for the heat-melting coloring material layer will be reduced, whereas if it exceeds the upper limit value, This is because the mechanical strength of the film decreases and the fine particles covered with the film come off, which may impede the production of a release layer or a heat-melting coloring material layer composed of the fine particles and the film. A more preferable composition ratio of surfactant and film forming material is in the range of 10:90 to 60:40.

(C) Heat-melt coloring material layer This heat-melting coloring material layer is made of an organic substance and a colorant that melt at a predetermined temperature, and is placed on the release layer to a thickness greater than the convex portion of the release layer (and whose surface is It is coated so that it is flat.

The above-mentioned heat-melting coloring material layer needs to have a flat surface in order to increase the number of contact points and achieve good transfer to a transfer material with a low surface smoothness such as plain paper. . Specifically, in a state in which a heat-fusible coloring material layer is coated on a release layer on which convex portions are formed, it is made thicker than the convex portions, and the center line average roughness of the surface is 0.1 to 0.5 μm. It is desirable to do so.

In this case, the convex portion of the release layer is buried in the heat-melting coloring material layer.

The organic substance that is one of the components constituting the heat-melting coloring material layer is not particularly limited as long as it is a wax that has been used in conventional heat-sensitive transfer recording materials. Examples of such organic substances include paraffin wax, carnauba wax, beeswax, polyethylene wax, microcrystalline wax, amide wax, ester wax, oxidized polyethylene wax, rhodinamethylolated amide,
Examples include higher fatty acids and higher alcohols.

Furthermore, the flexibility of the heat-melting color material layer can be increased by adding low-molecular-weight petroleum resins, ethylene-vinyl acetate copolymers, ethylene-acrylic acid ester copolymers, etc. to these organic substances. good.

Examples of the coloring agent, which is the other component constituting the heat-melting coloring material layer, include carbon black, pigments and dyes used in conventional heat-sensitive transfer recording materials, and the like.

(Function) According to the heat-sensitive transfer recording material of the present invention, a release layer in which convex portions are formed is provided on a sheet-like base material, and a heat-melting coloring material layer is further applied on the release layer to form a convex portion on the release layer. By coating the peeling layer so that it is thicker and has a flat surface, when thermal energy is applied from a heating element such as a thermal head, the surface of the peeling layer is thermally melted by the action of the surfactant contained in the peeling layer. This makes it easier to transfer from a coloring material layer to a transfer material with a high surface roughness, and the improved releasability eliminates peeling caused by mechanical dragging of the heat-melting coloring layer around the transfer dots. It is possible to form an excellent transferred image on the transfer material by balancing the mutually contradictory properties of preventing dots by the anchoring effect of fine particle powder of a predetermined particle size dispersed in the layer and ensuring good dot sharpness. □ That is, by incorporating a surfactant into the film constituting the release layer, when thermal energy is applied by a heating element, the heat-melting coloring material layer coated on the release layer can be transferred to the transfer material. Good transferability can be achieved. However, improving the transferability of the heat-melting coloring material layer also improves the releasability of the coloring material layer surrounding the dots, which leads to deterioration of the sharpness of the dots due to mechanical dragging of the coloring material layer. For this reason, in the present invention, the release layer is composed of a coating made of a surfactant and a film-forming material that covers the surface of the base material, and fine particles of a predetermined particle size that are dispersed while being covered with this coating, By forming a structure in which convex portions are formed at locations corresponding to the fine particles, the heat-melting coloring material layer can be held on the release layer by the anchoring effect of the convex portions.

As a result, when the heat-melting coloring material layer is heated by the heating element to melt the transfer dot portions, the anchoring effect of the convex portions of the release layer is lost, and only the release effect acts. On the other hand,
The heat-melting coloring material layer surrounding the transfer dot is mechanically held in a solid state by the anchoring effect of the convex portion of the release layer, so when the transfer dot is transferred onto the transfer material and peeled off, the surrounding area is not dragged. It is possible to suppress the dots from peeling off and to achieve so-called sharpness of the dots. Therefore, it is possible to achieve both the improvement in transferability due to the release layer and the sharpness of the dots, so that an excellent transferred image can be formed on the transfer material.

(Example) Examples of the present invention will be described in detail below.

Example 1 First, the back side was back-coated with a heat-resistant slipping layer with a thickness of 6 μm.
Release composition A having the following composition is applied to the surface of the polyester sheet of
was pumped with a tube pump while stirring to prevent precipitation of the silicone resin particles therein, and then coated with a bar coater (4cm).
) and dried to form a release layer with a thickness of 0.69/m2. When this release layer was observed using a scanning electron microscope, it was found that fine particles were present either singly or in groups of 5 to 10 particles dispersed in the release layer, and convex portions were formed at locations corresponding to the fine particles. It was confirmed that Further, when observed with the naked eye, convex portions formed by fine particles were uniformly present on a macroscopic level.

[Removal composition A] Silicone resin fine particles with an average particle size of 2 μm (trade name: X C99-501, manufactured by Toshi Silicone Co., Ltd.) 2 parts by weight urethane resin emulsion (trade name, manufactured by Sanyo Chemical Co., Ltd.; Permarin U A 200)
5 parts by weight Sodium lauryl sulfate
0.8 parts by weight water 7
2 parts by weight isopropyl alcohol 2
0 weight 11 parts Next, the following hot-melt coloring material composition A was mixed and dispersed under heating to form an ink coating material A for forming a hot-melting coloring material layer.
was prepared. Subsequently, this ink paint A was applied to the release layer on the polyester sheet using a bar coater (N1112) and dried to produce a heat-sensitive transfer recording material. The surface roughness of this thermal transfer recording material was in the range of 0.3 to 0.5 μm in terms of center line average roughness.

[Thermofusible coloring material composition A] Carbon black (trade name manufactured by Degussa; Pr1ntex35)
20 parts by weight ethylene-vinyl acetate copolymer (trade name manufactured by Mitsui Polychemical Co., Ltd.; Evaf'fexV
577) 10 parts by weight Carnapax No. 1
20 parts by weight paraffin wax (melting point = 88
~70”C) 50!1ffi parts toluene
i50 weight part implementation f! 42 First, the back side was coated with a heat-resistant slipping layer with a thickness of 6 μm.
Release composition B having the following composition is applied to the surface of the polyester sheet of
was pumped with a tube pump while stirring to prevent precipitation of the silicone resin particles therein, and then coated with a bar coater (4cm).
) and dried to form a release layer with a thickness of OJ9/m2. When this release layer was observed using a scanning electron microscope, it was found that the fine particles were dispersed in the release layer either singly or in groups of two or three particles, and convex portions were formed at locations corresponding to the fine particles. It was confirmed that Further, when observed with the naked eye, convex portions due to fine particles were uniformly present on a macroscopic level.

[Removal composition B] Silicone resin fine particles with an average particle size of 5 μm (trade name, X C99-301, manufactured by Toshi Silicone Co., Ltd.) 2 parts by weight Polyvinyl alcohol 2 parts by weight Sodium dodecylbenzenesulfonate 1 part by weight Water 75 parts by weight Isopropyl alcohol Next, 20 parts by weight of the same ink paint A as in Example 1 was applied to the release layer on the polyester sheet using a bar coater 1t12) and dried to produce a heat-sensitive transfer recording material.

Example 3 First, the back side was back-coated with a heat-resistant slipping layer with a thickness of 6 μm.
A release composition C having the following composition is applied to the surface of the polyester sheet of
was pumped with a tube pump while stirring to prevent precipitation of the acrylic resin fine particles therein, and then coated with a bar coater (Nl1
4) and dried to form a release layer with a film thickness of 0.79/m2. When this release layer was observed using a scanning electron microscope and with the naked eye, it was found that the fine particles were dispersed in the release layer either individually or as a group of 2 to 3 particles, and there were convex portions at the locations corresponding to the fine particles. It was confirmed that the protrusions were formed and that the protrusions were macroscopically uniform.

[Peeling composition C] Acrylic resin fine particles with an average particle size of 5 μm (trade name: 5P-30, manufactured by Soken Kagaku Co., Ltd.) 2
Part by weight Urethane resin emulsion (Product name: Permarin U A 150, manufactured by Sanyo Kasei Co., Ltd.)
5 parts by weight Sodium lauryl sulfate
0.6 parts by weight water
72 parts by weight isopropyl alcohol
2OIiffi Part Next, the same ink paint A as in Example 1 was applied to the release layer on the polyester sheet using a bar coater (Nu 12) and dried to produce a heat-sensitive transfer recording material.

Example 4 First, the back side was back-coated with a heat-resistant slipping layer with a thickness of 6 μm.
A release composition having the following composition was applied to the surface of a polyester sheet using a tube pump while stirring to prevent the silicone resin fine particles therein from settling.
) and dried to form a release layer with a thickness of 0.79/m2. When this release layer was observed using a scanning electron microscope and with the naked eye, it was found that the fine particles were dispersed in the release layer either individually or as a group of 2 to 3 particles, and there were convex portions at the locations corresponding to the fine particles. It was confirmed that the protrusions were formed and that the protrusions were macroscopically uniform.

[Removal composition C] Silicone resin fine particles with an average particle size of 2 μm (trade name, manufactured by Toshi Silicone Co., Ltd., X C99-501) 2 parts by weight' Elvacite 201O (trade name, manufactured by DuPont) 2 parts by weight Polyoxyethylene sorbitan monomer Stearate: 1 part by weight Toluene: 95 parts by weight Next, the same ink paint A as in Example 1 was applied to the release layer on the polyester sheet using a bar coater (N[112) and dried to produce a heat-sensitive transfer recording material. .

Comparative Example 1 First, the back side was back-coated with a heat-resistant slipping layer with a thickness of 6 μm.
Release composition E having the following composition is applied to the surface of the polyester sheet of
The release composition A (from which fine particles were removed) was pumped using a tube pump, coated using a bar coater (N114), and dried to form a release layer with a thickness of 0.39/m''.

[Removal composition E] Urethane resin emulsion (trade name: Vermarine UA2QO, manufactured by Sanyo Chemical Co., Ltd.) 5
Part by weight Sodium lauryl sulfate 0.
6 parts by weight water
721i parts isopropyl alcohol
Next, 20 parts by weight of the same ink paint A as in Example 1 was applied to the release layer on the polyester sheet using a bar coater (
NQ12) was applied and dried to produce a heat-sensitive transfer recording material.

Comparative Example 2 First, the back side was back coated with a heat-resistant slipping layer with a thickness of 6 μm.
A release composition F having the following composition is applied to the surface of the polyester sheet of
The release composition B (excluding fine particles) was pumped using a tube pump, coated using a bar coater (N[14), and dried to form a release layer with a thickness of 0.49/m2.

[Release Composition F] Polyvinyl alcohol 2 parts by weight Sodium dodecylbenzenesulfonate 1 part by weight Water 75 parts by weight Isopropyl alcohol 20 parts by weight Next, ink paint A similar to Example 1 was applied to the release layer on the polyester sheet using a bar coater ( A heat-sensitive transfer recording material was produced by coating and drying using Nci12).

Comparative Example 3 First, the back side was back coated with a heat-resistant slipping layer with a thickness of 6 μm.
A release composition G having the following composition is applied to the surface of the polyester sheet of
(The above-mentioned stripping composition C excluding fine particles) is pumped with a tube pump and coated using a bar coater (part 4),
It was dried to form a release layer with a thickness of 0.3 g/m''.

[Peeling composition G] Urethane resin emulsion (trade name, manufactured by Sanyo Chemical Co., Ltd.; Permarin UA150) 5
Part by weight Sodium lauryl sulfate 0.
6 parts by weight water
72 parts by weight isopropyl alcohol
2C1ffl m parts Next, the same ink paint A as in Example 1 was applied to the release layer on the polyester sheet using a bar coater (NQ12) and dried to produce a heat-sensitive transfer recording material.

Comparative Example 4 First, the back side was back coated with a heat-resistant slipping layer with a thickness of 6 μm.
A release composition H having the following composition was applied to the surface of the polyester sheet.
(The above-mentioned release composition excluding fine particles) is pumped using a tube pump, coated using a bar coater (N13), and dried to form a release layer with a film thickness of 0.3°'57''〉m2. did.

[Removal composition H] Elvacite 2010 (trade name manufactured by DuPont)
2 parts by weight Polyoxyethylene sorbitan monostearate 1 part by weight Toluene 95 parts by weight Next, the same ink coating A as in Example 1 was applied to the release layer on the polyester sheet using Vernier-9 (N111).
2) was applied and dried to produce a heat-sensitive transfer recording material.

Comparative Example 5 The same ink paint A as in Example 1 was applied to the surface of a 6 μm thick polyester sheet whose back surface was back coated with a heat-resistant slipping layer.
was directly coated using a bar coater (Nl112) and dried to produce a heat-sensitive transfer recording material.

The thermal transfer recording materials of Examples 1 to 4 and Comparative Examples 1 to 5 were transferred onto electrophotographic plain paper with a Beck smoothness of 30 seconds by a test printer incorporating an 8 dot/M thermal head. did. At this time, three points were evaluated: void ratio (ratio of transferred ink area to original image area) and transfer dot breakage.

The results are shown in Table 1 below.

Table 1 As is clear from Table 1 above, the thermal transfer recording materials of Examples 1 to 4 have extremely good transferability to plain paper.

Example 5 A release layer made of the release composition A and having a thickness of 0.69/m2 was formed on the surface of an 8 μm thick polyester sheet whose back surface was back coated with a heat-resistant slipping layer. Subsequently, the following heat-melting color material composition B was mixed and dispersed under heating to prepare an ink paint B for forming a heat-melt color material layer, and then this ink paint B was applied to the release layer on the polyester sheet. The mixture was coated using a bar coater (m12) and dried to produce a heat-sensitive transfer recording material. The surface roughness of this thermal transfer recording material was in the range of 0.3 to 0.5 μm in terms of center line average roughness.

[Thermofusible coloring material composition B] SOT Blue 1 15 parts by weight Ethylene-vinyl acetate copolymer (trade name manufactured by Mitsui Polychemical Co., Ltd.; Evaff'exV
31G) 15 parts by weight Hoechst wax (trade name manufactured by Hoechst) 20 parts by weight Paraffin wax (melting point =
68-70°C) 50 parts by weight Example 6 A release layer with a thickness of 0.89/m2 made of the release composition B was formed on the surface of a 6 μm thick polyester sheet whose back surface was back coated with a heat-resistant slipping layer. . Subsequently, the same ink paint B as in Example 5 was applied to the release layer on the polyester sheet using a bar coater (Ka 12) and dried to produce a heat-sensitive transfer recording material.

Example 7 A release layer made of the release composition C and having a thickness of 0.79/m2 was formed on the surface of a 6 μm thick polyester sheet whose back surface was back coated with a heat-resistant slipping layer. Subsequently, the same ink paint B as in Example 5 was applied to the release layer on the polyester sheet using a bar coater (NQ 12) and dried to produce a heat-sensitive transfer recording material.

Example 8 A release layer with a thickness of 0.89/m 2 made of the above-mentioned release composition was formed on the surface of a 6 μm thick polyester sheet whose back surface was back coated with a heat-resistant slipping layer. Subsequently, the same ink paint B as in Example 5 was applied to the release layer on the polyester sheet using a bar coater (N[112) and dried to produce a heat-sensitive transfer recording material.

Comparative Example 6 A release layer made of the release composition E and having a thickness of OJ9/m2 was formed on the surface of a 6 μm thick polyester sheet whose back surface was back coated with a heat-resistant slipping layer. Next, Example 5
An ink paint B similar to the above was applied to the release layer on the polyester sheet using a bar coater (Nfl12) and dried to produce a heat-sensitive transfer recording material.

Comparative Example 7 A release layer made of the release composition F and having a thickness of 0.4 g/m2 was formed on the surface of a 6 μm thick polyester sheet whose back surface was back coated with a heat-resistant slipping layer. Subsequently, the same ink paint B as in Example 5 was applied to the release layer on the polyester sheet using a bar coater (Nn12) and dried to produce a heat-sensitive transfer recording material.

Comparative Example 8 A release layer made of the release composition G and having a thickness of OJ9/m2 was formed on the surface of a 6 μm thick polyester sheet whose back surface was back coated with a heat-resistant slipping layer. Next, Example 5
Ink paint B similar to the above was applied to the release layer on the polyester sheet using a bar coater (m12) and dried to produce a heat-sensitive transfer recording material.

Comparative Example 9 A release layer made of the release composition H and having a thickness of OJ9/m2 was formed on the surface of a 6 μm thick polyester sheet whose back surface was back coated with a heat-resistant slipping layer. Next, Example 5
An ink paint B similar to the above was applied to the release layer on the polyester sheet using a bar coater (Nl112) and dried to produce a heat-sensitive transfer recording material.

Comparative Example 10 Ink paint B similar to Example 5 was applied to the surface of a 6 μm thick polyester sheet whose back surface was back coated with a heat-resistant slipping layer.
was directly coated using a bar coater (Nn12) and dried to produce a heat-sensitive transfer recording material.

As in Example 1, the thermal transfer recording materials of Examples 5 to 8 and Comparative Examples 6 to 10 were 8 dots/m2.
The image was transferred onto electrophotographic plain paper with a Beck smoothness of 30 seconds using a test printer equipped with a thermal head. At this time, three points were evaluated: void rate and transfer dot breakage. The results are shown in Table 2 below.

Table 2 As is clear from Table 2 above, the thermal transfer recording materials of Examples 5 to 8 have extremely good transferability to plain paper.

[Effects of the Invention] As detailed above, the thermal transfer recording material of the present invention provides various effects listed below.

(2) The release layer is composed of a film made of a surfactant and a film-forming material coated on a sheet-like base material, and fine particles of a predetermined particle size dispersed and covered in this film, and By forming a structure in which convex portions are formed at corresponding locations, the releasability of the heat-melting coloring material layer on the release layer can be improved and transfer to a transfer material such as plain paper with low smoothness can be facilitated. At the same time, the anchoring effect of the protrusions prevents the mechanical dragging of the heat-melting coloring material layer around the transferred dots due to improved releasability, ensuring good dot sharpness, resulting in faithful to the recorded image. Excellent images can be transferred to materials with low surface smoothness.

■The heat-melting coloring material layer has excellent releasability, allowing thermal transfer with lower energy compared to conventional thermal transfer recording materials, improving transfer sensitivity and achieving high-speed recording. .

(2) Thermal transfer recording materials utilize the peeling effect of the surfactant in the film that constitutes the release layer, so the film forming material, which is another component of the film, has a high glass transition temperature or high softening temperature. Thermoplastic resins and thermosetting resins can be used. Therefore, good releasability can be achieved without mixing a release agent with a low melting point (for example, a wax with a low melting point) into the release layer as in the past. As a result, even if a heat-melting coloring material layer with a high melting point is applied on the release layer, the release layer serving as the base can be prevented from melting, so that a stable heat-sensitive transfer recording material can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the basic structure of the thermal transfer recording material of the present invention. DESCRIPTION OF SYMBOLS 1... Sheet-like base material, 2... Back coat layer, 3...
... Peeling layer, 3a... Coating, 3b... Fine particles, 4.
...Thermofusible coloring material layer. Applicant's agent Patent attorney Takehiko Suzue Figure 1

Claims (1)

[Scope of Claims] (a) a sheet-like base material; (b) a coating provided on the base material and comprising a surfactant and a film-forming material; and fine particles dispersed while being covered by the coating. and (c) a coating on the release layer that is thicker than the protrusions of the release layer and has a flat surface. A heat-sensitive transfer recording material comprising: a heat-melting coloring material layer;