JPS6356492A - Transfer-type thermal recording material - Google Patents

Abstract

PURPOSE:To obtain favorable intermediate gradations with high sensitivity, by using a resin having a melt viscosity of not more than a predetermined value which is obtained by modifying at least one of specified resins as a resin A, in a thermal recording material provided with a coloring material layer comprising a coloring material and the resin A on a base by coating. CONSTITUTION:A coloring material layer 4 comprising a resin A2 and a coloring material 3 is provided on one side of a base 1. The base 1 may be a polyester film, a polyimide film, a cellulose film or the like, with or without a heat- resistant lubricating layer on one side of the film. The resin A2 may be a styrene resin, an acrylic resin, a styrene-acryl copolymer resin, an unsaturated acid amide resin, an unsaturated carboxylic acid resin, an unsaturated carboxylic acid ester resin or the like which is modified to have a melt viscosity at 100 deg.C of not more than 300cP. By this, favorable intermediate gradations can be obtained with high sensitivity.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a heat-sensitive recording material used for heat-sensitive recording, and more particularly to a transfer-type heat-sensitive recording material whose viscosity decreases in response to a thermal signal and provides good halftones. .

2. Description of the Related Art Conventionally, transfer-type heat-sensitive recording materials in this field include an ink material containing an alicyclic saturated hydrocarbon resin and a coloring material, and this ink, as described in Japanese Patent Application No. 59-246649. A thermal transfer layer has been proposed in which ink transfer auxiliary particles having a particle size larger than the thickness of the layer made of the material are mixed into the ink layer.

Problems to be Solved by the Invention Conventional transfer type thermal recording materials that provide good halftones have had the problem of low sensitivity.

An object of the present invention is to provide a transfer type heat-sensitive recording material that has high sensitivity and provides good halftones.

Means for Solving the Problems A thermosensitive recording material is provided, in which a coloring material layer containing a coloring material and a resin is coated on a base material, in which the resin A is a styrene resin, an acrylic resin, or a styrene-acrylic copolymer.

Unsaturated acid amide resin, unsaturated carboxylic acid resin.

At least one type of unsaturated carboxylic acid ester resin is modified to have a melt viscosity of 300 at 100°C.
Use a resin with a centipoise or less.

Although the details of the action are unknown, it is thought that the melt viscosity at 100°C contributes to the sensitivity and tackiness.

Embodiment FIG. 1 is a sectional view illustrating, as a model, an embodiment of the transfer type heat-sensitive recording material of the present invention. Resin A on one side of base material 1
In this embodiment, a coloring material layer 4 including a coloring material 2 and a coloring material 3 is provided.

The base material 1 may be a polyester film, a polyimide film, a polycarbonate film, a polyamide film, a cellulose film, or a film in which a stone-thermolubricious layer is provided on one side of these films.

Examples of the resin A2 include styrene resin, acrylic resin, styrene-acrylic copolymer, unsaturated acid amide resin, unsaturated carboxylic acid resin, unsaturated carboxylic acid ester resin, etc. A resin having a melt viscosity of 300 centipoise or less at °C is provided.

Modification here refers to fatty acid amide, 2゜2-bis(4'-oxyphenyl)propane or bis(
It refers to reacting bisphenol derivatives such as 4'-oxydiphenyl)methane with the above resin. Resin A2
The lower the melt viscosity at 100° C., the higher the sensitivity of the transfer type heat-sensitive recording material.

High sensitivity here refers to the amount of energy applied to the heat source when performing thermal transfer recording. The lower the energy, the higher the sensitivity.

The third color may be a dye, an inorganic pigment, or an organic pigment.

The coloring material layer 4 is applied onto the base material 1 by, for example, a hot melt coating method or a solvent coating method.

FIG. 2 shows a cross-sectional view for explaining another embodiment of the transfer type heat-sensitive recording material of the present invention in a model manner, and shows a color containing resin A2, coloring material 3, and resin B5 on one side of the base material 1. This is a form in which a material layer 6 is provided.

The resin 135 is a resin having a higher melt viscosity at 100°C than resin A, such as vinyl chloride/vinyl acetate copolymer, low molecular weight polystyrene, phenol resin, xylene resin, ethylene/vinyl acetate copolymer, acrylonitrile/styrene. Copolymers, butyral resins, acrylic resins, styrene/acrylic resins, etc. are provided.

Resin B5 has the effect of softening the thermal viscosity characteristics of the coloring material layer 6, and the relationship between pulse width and recording density (density characteristics) from the pulse width at the rise to the pulse width at the highest density (
Expand the range of tone reproduction.

The coloring material layer 4 or 6 may contain wax. Examples of this wax include bleached honey anchor, candelilla wax, carnauba wax, and paraffin wax.

The wax has the effect of sharpening the thermal viscosity characteristics of the coloring material layer 4 or 6, and makes the density characteristics higher in sensitivity than in the case of only resin A2.

Further, the coloring material layer 4 or 6 may contain particles. These particles have the effect of making the coloring material layer 4 or 6 easier to tear. Further, when the particles have a particle size larger than the thickness of the coloring material layer 4 or 6, in addition to the above-mentioned effect, the particles also act as transfer auxiliary particles that primarily transfer.

Examples of the material for the particles include aluminum oxide.

Examples include titanium oxide, calcium carbonate, silicon dioxide, polycarbonate, nylon, guanamine resin, polypropylene, and the like.

The particle size of the particles is preferably within 20 μm. If it is larger than 20 μm, the particle heat container becomes too large, resulting in low sensitivity.

Examples will be specifically described below.

Example-1 A coating liquid was prepared with the composition described below.

Resin A: styrene-acrylic copolymer fatty acid amide modified resin Perfecta 603 0-1 (manufactured by Hitachi Chemical Co., Ltd., hereinafter the same) 20 parts by weight Coloring material: Carbon black... 9 parts by weight Solvent: toluene 100 parts by weight or more of the composition was dispersed in a ball mill for 200 hours to prepare a coating liquid.

This coating liquid was applied onto a 9 μm thick polyester film.
It was coated with a percoater, and the solvent was dried to a thickness of 2 μm to obtain Recording Body-1.

Example-2 Resin A: Perfecta 6030-1 20 parts by weight Resin B: Butyral resin-containing Slets (manufactured by @1 Suikagaku Kogyo Co., Ltd.) 5 parts by weight Coloring material : Phthalocyanine cyan pigment...1 part by weight Solvent: Toluene...100 parts by weight or more of the composition was dispersed in a ball mill for 15 hours to prepare a coating liquid.

This coating liquid was applied onto a 9 μm thick polyester film.
It was coated with a percoater and the solvent was dried to a thickness of 10 μm to obtain a recording medium-2.

Example-3 A coating liquid was prepared with the composition described below.

Resin A: Perfecta 6030-1 20 parts by weight Wax: Paraffin wax HAD5080 (manufactured by Nippon Seiro Co., Ltd.) 2 parts by weight Coloring material: Disazo yellow pigment 20 parts by weight 5 parts by weight Solvent: toluene 100 parts by weight or more of the composition was dispersed in a ball mill for 15 hours to prepare a coating liquid.

This coating liquid was applied onto a 9 μm thick polyester film.
It was coated with a percoater and the solvent was dried to a thickness of 5 μm to obtain a recording material-3.

Example-4 A coating liquid was prepared with the composition described below.

Resin A: Perfecta 603 0-2, a fatty acid amide modified resin of styrene-acrylic copolymer (manufactured by Hitachi Chemical Co., Ltd.) 20 parts by weight Coloring material: Quinacridone magenta pigment... ...15 heavy all particle aluminum dioxide fused white alumina w
l+4000 (manufactured by Fujimi Abrasives Industry Co., Ltd.)...
・10 parts by weight Solvent: toluene After dispersing 100 parts by weight or more of the composition other than the inner particles in a ball mill for 15 hours,
Particles were added to this dispersion liquid and dispersed in a ball mill for 1 hour to obtain a coating liquid.

This coating liquid was applied onto a 9 μm thick polyester film.
It was coated with a percoater and the solvent was dried to a thickness of 5 μm to obtain a recording material-4.

Example-5 Resin A: 50 parts by weight of 2 moles of ethylene oxide adduct of 2.2-bis(4'-oxydiphenyl)propane, 15.5 parts by weight of maleic anhydride, and 30 parts by weight of toluene were heated at 100°C. The mixture was stirred and kept warm for 4 hours to obtain an intermediate.

Next, 44 parts by weight of this intermediate, 50 m2 parts of styrene, 10 parts by weight of methyl methacrylate, 30 parts by weight of toluene, and 2 parts by weight of benzoyl peroxide were heated to 100°C.
The mixture was kept warm for 6 hours to obtain a polymer solution. Subsequently, this polymer solution was desolventized under reduced pressure to obtain Resin-1.

Resin-1...20 parts by weight Coloring material: Carbon black...Type 5 plate Solvent: Toluene...
... 100 parts by weight or more of the composition in a ball mill
It was dispersed for a period of time to form a coating liquid.

This coating liquid was applied onto a 9 μm thick polyester film.
It was coated with a percoater and the solvent was dried to a thickness of 15 .mu.m to obtain a recording material-5.

Comparative example-1 A coating liquid was prepared with the composition described below.

Alicyclic saturated hydrocarbon resin: Alcon P-70 (manufactured by Arayo Kagaku Kogyo Co., Ltd.) 20 parts by weight Colorant: Phthalocyanine cyan M material 8 parts by weight Solvent: Xylene ...... 100 parts by weight or more of the composition was dispersed in a ball mill for 15 hours to prepare a coating liquid.

This coating liquid was applied onto a 9 μm thick polyester film.
It was coated with a bar coater, and the solvent was dried to a thickness of 3 μm to form a recording medium-1'.

Using the above recording bodies 1 to 5 and 1', low molecular weight polystyrene: Hymer 5T was printed on polypropylene synthetic paper.
-95 (manufactured by Sanyo Chemical Industries, Ltd.) was coated with a thickness of 2 μm, and recording was performed under the following recording conditions.

<Recording conditions> Thermal head: 4 dots/mm (thin film flat line head) Recording cycle: 16.7 ms/line applied power: 5 mW/mm2 Applied pulse width: 0 to 4 m5 (recorded by pulse width modulation in 16 steps) The results are shown in Table 1.

Table 1 (However, sensitivity indicates the step at which the recording density rises in recording density characteristics) As is clear from Table 1, the recording medium of the present invention (recording body 1
-5) have higher sensitivity than the comparative example (recording body 1').

Recording body 2 had a wider tone reproduction range than recording body 1 because butyral resin was mixed into recording body 1.

Recording body 3 had higher sensitivity than recording body 1 because wax was mixed into recording body 1.

Furthermore, the recording medium of the present invention provided good intermediate tones that rose smoothly from the density on the paper surface.

Similar results were also obtained with modified styrene resin, modified acrylic resin, modified unsaturated acid amide resin, modified unsaturated carboxylic acid resin, and modified unsaturated carboxylic acid ester.

Effect of the invention The transfer type heat-sensitive recording material of the present invention is made of styrene resin.

At least one type of the group consisting of acrylic resin, styrene/acrylic copolymer, unsaturated acid amide resin, unsaturated carboxylic acid resin, and unsaturated carboxylic acid ester is modified to have a melt viscosity of 300 centipoise or less at 100°C. Since this resin is used, it has the effect of providing high sensitivity and good halftones.

[Brief explanation of the drawing]

FIG. 1 is a sectional view illustrating one embodiment of the present invention in a model manner, and FIG. 2 is a sectional view illustrating another embodiment of the present invention in a model manner. 1...Base material, 2...Resin A, 3...Coloring material,
4.6...Coloring material layer, 5...Resin B.

Claims (4)

[Claims] (1) A heat-sensitive recording material in which a coloring material layer containing a coloring material and a resin A is coated on a base material, wherein the resin A is a styrene resin, an acrylic resin, a styrene-acrylic copolymer, or an unsaturated acid amide. A transfer type thermal recording characterized in that the resin is modified with at least one member selected from the group consisting of a resin, an unsaturated carboxylic acid resin, and an unsaturated carboxylic ester to have a melt viscosity of 300 centipoise or less at 100°C. body. (2) The colorant layer has a melt viscosity of resin A at 100°C.
The transfer type heat-sensitive recording material according to claim 1, characterized in that it contains a higher content of resin B. (3) The transfer type heat-sensitive recording material according to claim 1 or 2, wherein the coloring material layer contains wax. (4) The transfer type heat-sensitive recording material according to any one of claims 1 to 3, wherein the coloring material layer contains particles.