JPS6094388A - Thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To obtain highly sensitive, high-density color transferred pictures many times by providing a colorant holding layer containing a fine porous substance, a colorant, and a thermoplastic fatty acid amide in solid state at ordinary temperature on a supporter. CONSTITUTION:A coating composition, consisting of a fine porous substance, a colorant, and a thermoplastic fatty acid amide, is prepared, in which 0.5-10pts. wt. fine porous substance and 0.1-10pts.wt. colorant are preferably used on the basis of 1pt.wt. thermoplastic fatty acid amide. The coating composition is hot- melted and coated on a base material, e.g., papers, resin films, metal sheets, etc., to form a colorant holding layer of a thickness of 20mum or less in order to obtain a thermal transfer recording medium. The fine porous substance used includes vinyl resins, acrylic resins, etc., and the colorant used may be properly selected from the well-known colorants.

Description

[Detailed description of the invention] [Technical field] The present invention relates to thermal transfer recording media that can be used multiple times.

Specifically, the present invention relates to a thermal transfer recording medium that exhibits a small decrease in density with the number of uses, can be printed with low energy, has high sensitivity, and has high density and excellent resolution.

[Prior Art] As a thermal transfer recording medium intended for multiple use, there is, for example, an invention described in Japanese Patent Application Laid-Open No. 54-68253. This invention is a technology in which a microporous layer is formed using a resin and the pores are impregnated with heat-sensitive ink, but the density of the dye transfer image is low, and in order to obtain a high density dye transfer image, it is necessary to Energy is required, and even if a high-density dye transfer image is obtained by applying high energy,
The edges of the printed image lack sharpness. Japanese Patent Publication No. 55-105
579 and Japanese Unexamined Patent Publication No. 57-36698.
A similar technology to Biped has been disclosed, but exhibits the same drawbacks.

In addition to the above, heat-sensitive transfer recording media that can be used many times using various techniques are being considered. For example, JP-A-57-1
As shown in Japanese Patent No. 85195, a method of crafting carbon black with monomer monomer, No. 55-5
A method of roughening the ink layer side of a support as shown in Publication No. 5887, No. 57-138984, No. 58-1
As shown in Japanese Patent No. 16193, there are known ones in which an intermediate layer for adhesion is provided between the base material and the ink layer.

These prevent all of the colorant from being transferred at once when heated with a thermal head, and although each of them is effective to some extent, it is still insufficient.

[Objective of the Invention] The object of the present invention is to enable low-energy printing, to have high sensitivity, and to reduce the decrease in density with respect to the number of times of use.
An object of the present invention is to provide a heat-sensitive transfer recording medium on which high-density dye transfer images can be printed many times.

Other objects of the invention will become apparent from the following description of the specification.

[Summary of the Invention] As a result of intensive research, the present inventor has developed a heat-sensitive transfer recording medium having a colorant-retaining layer containing a microporous substance, a colorant, and a solid component that is solid at room temperature on a support. , by being a solid component or a thermofusible fatty acid amide.
The inventors have discovered that two and one objectives can be achieved, leading to the present invention.

[93, Ming composition The present invention will be explained in more detail below.

The thermal transfer recording medium of the present invention has at least one colorant-retaining layer on a support, and the colorant-retaining layer contains at least one each of a microporous substance, a colorant, and a solid component. do.

The solid component used in the present invention is a fatty acid amide.

Examples of the fatty acid amide include thermofusible fatty acid amides such as lauric acid amide, myristic butyamide, palmitic butyamide, stearic acid amide, and oleic acid amide. These may be used alone or in combination of two or more. Furthermore, other conventionally known solid components that are solid at room temperature, such as paraffin wax, microcrystalline wax, carna/hewax, ester wax, stearic acid, stearic acid monoglyceride, pentaerythritol stearate, stearyl alcohol, etc. (It may also be used for Jl.

In this case, the fatty acid amide of the present invention accounts for 5% of the total solid components.
It is preferable that the content is less than 0% (weight %).

As the microporous material in the present invention, the above-mentioned Japanese Patent Application Publication No. 5
Conventionally known microporous materials described in Publications No. 4-68253, No. 55-105579, etc. can be used without any particular limitations. The coloring material retaining layer of the present invention can be made into a layer made of a microporous material by using the resins described in the publication, etc., and by the method described in the publication. The resins preferably used as the microporous material of the present invention include vinyl resins (e.g., polyvinyl chloride, polyvinyl acetate, polyvinyl fluoride, polyvinyl butyral, polyvinylidene chloride, polyvinyl alcohol, vinyl chloride-acetic acid). (vinyl copolymer, vinyl chloride-vinylidene chloride copolymer, polystyrene, polyethylene, etc.), acrylic resin (e.g., polyacrylic ester, polymethacrylic acid ester, etc.), cellulose resin (e.g., ethyl cellulose, cellulose acetate, etc.) ), and may also be polyamide, gelatin, gum arabic, etc. A method of making a microporous material using these resins is also disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 55-105579, etc.
These methods can also be applied to the present invention.

As the coloring agent in the present invention, the above-mentioned JP-A-54-68
Conventionally known colorants described in JP-A No. 253, JP-A No. 55-105579, etc. can be used without any particular limitation. That is, the coloring agent of the present invention may be appropriately selected from conventionally known dyes, such as direct dyes, acid dyes, basic dyes, disperse dyes, and oil-soluble dyes. The coloring matter used in the coloring material layer of the present invention may be any pigment that can be transferred (transferred) together with a heat-fusible substance, so it may be a pigment in addition to the above. In addition, specifically, the following can be mentioned. That is, the yellow pigments include Kayalon Polyester Light Yellow 5G-3 (Nippon Kayaku) and Oil Yellow 5-3.
7 (white clay), Eisensviron GRH Special (Hodogaya), Sumiplast Yellow FG (Sumitomo), Eisenspiron Yellow GRH (Hodogaya), etc. are preferably used.

As a red pigment, Taiaceridone Fast Red R (
Mitsubishi Kasei), Dianex Brilliant Red BS-
E (Mitsubishi Kasei), Sumiplus Trend FB (Sumitomo),
Sumiplast Tread HFG (Sumitomo), Chill Pink RCL-E (Nippon Kayaku) for Kayalon Polye, Eisen Spiron Red GEH Special (Hodogaya), etc. are preferably used. As blue pigments, Diaceriton Fast Brilliant Blue R (Mitsubishi Kasei), Guianinx Blue EB-E (Mitsubishi Kasei), Kayalon Polyester Blue B-5F Conch (8 Mokuyaku), Sumiplast Blue 3
R (Sumitomo), Sumiplast Blue G (Sumitomo), etc. are preferably used. In addition, as a yellow pigment, Hansa Yellow 3
G, Taldrazine Lake, etc. are used, and the red pigment is Brilliant Carmine FB-Pure (Sanyo Color).
, Brilliant Carmine 6B (Sanyo Dyes), Alizarin Lake, etc. are used, and as blue pigments, Cerulean Blue, Sumitocyanine Blue GN-〇 (Sumitomo), Phthalocyanine Blue, etc. are used, and as black pigments, carbon Black, oil black, etc. are used. In addition, metal particles or metal oxides may also be used.

The composition ratio of the coloring material retaining layer of the present invention is not limited, but for 1 part (parts by weight, the same applies hereinafter) of the fatty acid amide of the present invention,
Microporous material Q 0.5-10 parts, colorant 0.1-+o
It is preferable to use the range of 61i.

In the heat-sensitive transfer recording medium of the present invention, techniques suitable for applying the colorant-retaining layer to a support such as a polymer film are described in the above-mentioned Japanese Patent Laid-Open No. 54-68253, Publication No. 55-105579, etc. These techniques are known in the industry and can be used in the present invention. For example, the coloring material retaining layer is a layer formed by solvent coating a coating solution prepared by dissolving or dispersing the composition in an appropriate solvent. As a coating method for the colorant retaining layer of the present invention, any known technique can be employed, such as a reverse roll coater method, an extrusion coater method, a gravure coater method, and a wire/stick coating method. The colorant retaining layer of the present invention may have a thickness of 20 liters or less, preferably 5 to 15 liters.

Note that the support used as a base material for the thermal transfer recording medium of the present invention is preferably a support that has heat-resistant strength, high dimensional stability, and high surface smoothness.

Materials include, for example, papers such as plain paper, capacitor paper, laminated paper, and Co-I paper, resin films such as polyethylene, polyethylene terephthalate, polystyrene, polypropylene, and polyimide, paper-resin film composites, and aluminum foil. Metal sheets such as the following are preferably used. The thickness of the support is preferably about 807 mm or less, particularly 3 to 20 mm, to provide good thermal conductivity. Moreover, the thermal transfer recording medium of the present invention is
The structure of the back side of the support is arbitrary.

The thermal transfer recording medium of the present invention may have other constituent layers such as an undercoat layer (for example, a layer for improving film adhesion).

[Effects of the Invention] According to the present invention, in a thermal transfer recording medium having a colorant-retaining layer containing a microporous substance, a colorant, and a solid component that is solid at room temperature on a support, the solid component is Since the composition is made of a fusible fatty acid amide, it is possible to achieve the objective of the present invention.

[Examples] Examples are given below, but the embodiments of the present invention are not limited thereto. In addition, "department" used below means "
Parts by weight.

Example 1 20 parts of vinyl chloride-vinyl acetate copolymer, 50 parts of ethyl acetate, and 10 parts of toluene were heated at 50°C in a ball mill.
The mixture was stirred for 2 hours to obtain a uniform resin solution (2).

Meanwhile, 5 parts of carbon blank, 5 parts of carnauba wax, and 110 parts of amyl stearate were heated to 80°C, and 1
The mixture was stirred for 2 hours to obtain a colorant component. Next, this colorant component was added to the resin solution (2) and stirred for 6 hours to obtain a dispersion coating liquid (2). Apply this coating solution (1) onto the polyethylene terephthalate film support for No. 8 using a wire parser.
jL,, was heated to 80°C and dried. The coating film thickness after drying was 12 colors.

Thermal printer (9: thermal element density 8 dots/m
A prototype machine equipped with a line thermal held for removing mold.

) was used to record (print) on plain paper by applying energy with an applied force of 0.6 W per heating element and an applied time of 1 millisecond. This was repeated 1 to 4 times. As the plain paper, commercially available "Bog/m'" paper was used.

Comparative Example 1 A thermal transfer recording medium sample (2) was obtained in exactly the same manner as in Example 1 except that stearic acid was used instead of stearic acid amide.

Comparative Example 2 A thermal transfer recording medium sample (2) was obtained in exactly the same manner as in Example 1 except that sorbitan fatty acid ester was used instead of stearic acid amide.

For each of the obtained samples (C and ■), printing was repeated many times in the same manner as in Example 1. As a result, as shown in FIG. On the other hand, the decrease in the density of the dye transfer image with respect to the number of printings was suppressed in sample (2) of the present invention.

Comparative Example 3 According to Example 1 of JP-A-54-68253, 10 parts of vinyl chloride/vinyl acetate copolymer, 7 parts of carnauba wax, 11 parts of castor wax, 4 parts of carbon black
A coating solution consisting of 51 parts of ethyl acetate, and 17 parts of toluene was solvent coated onto a carbon base paper and treated as described in the publication to obtain a thermal transfer recording medium sample (2). Further, according to the examples of JP-A-55-105579, 20 parts of vinyl chloride/vinyl acetate copolymer, 40 parts of common salt, 2 parts of p,p'-oxy-bis(benzenesulfonyl hydrazide), 760 parts of methyl ethyl keto, A coating solution consisting of 40 parts of heptane was solvent coated onto a 12 g thick polyester film and then treated as described in the example to obtain sample (2) of a thermal transfer recording medium having a microporous ink layer. Ta.

For these test samples 1■ and <φ, repeated printing was attempted on plain paper in the same manner as in Example 1 above. However, in both samples, only a dye transfer image with a density too low to be practical was obtained from the first print. Also, both samples ■, (5)
In order to obtain a transfer density comparable to that obtained with the dye transfer image obtained using sample tJ) of the present invention, approximately 2.4 times as much applied power was required. Moreover, the sharpness of the edges of the dye transfer images obtained from Samples [Co.] and (2) was several orders of magnitude inferior to that of Sample (2) of the present invention.

[Brief explanation of drawings]

FIG. 1 is a graph showing the relationship between the number of times of printing and the density of the dye transfer image for thermal transfer recording medium samples. Patent applicant Konishiroku Photo Industry Co., Ltd. Agent Patent attorney Nobuaki Sakaguchi (and 1 other person) Secret stock 0 (-

Claims (1)

[Claims] A heat-sensitive transfer recording medium having a colorant-retaining layer containing a microporous substance, a colorant, and a solid component that is solid at room temperature on a support, characterized in that the solid component is a thermofusible fatty acid amide. A thermal transfer recording medium.