JPS62176899A - Thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To provide a thermal transfer recording medium capable of performing transfer in a low energy level and imparting sharp printing even to rough paper and smooth paper, by forming two adjacent layers from an aqueous disperse composition and setting the thickness of the dry film of the layer near to a support to a specific range. CONSTITUTION:Among two laminated layers having different compositions, a heat- meltable substance is contained in the layer (heat-meltable layer 2) near to a support, and a thermoplastic polymer in the upper layer (thermoplastic layer 3) thereof. As the heat-meltable substance, a substance solid or semisolid at ambient temp. is designated and waxes, higher fatting acid, higher fatty acid ester, a rosin derivative, a synthetic resin, synthetic rubber, etc. having a melting or softening point of 25-120 deg.C are used. The thickness of the heat-meltable layer 2 is 0.5-35mum, pref., 1.7-2.7mum. As the thermoplastic polymer, an acrylic resin is pref. The surface of the constitution layer of a thermal transfer recording medium thus formed is superposed to a recording sheet such as plain paper and energy is applied to both of them in accordance with to image information by a thermal head, a thermal pen or a thermal recording apparatus using laser to transfer a colorant etc. to the recording sheet along with the thermoplastic substance.

Description

[Detailed description of the invention] 【Technical field】

The present invention relates to a thermal transfer recording medium, and more particularly to a thermal transfer recording medium that can be printed with low energy and provides clear printing on both rough paper and smooth paper.

[Background of the Invention 1] It is well known that a layer called an adhesive layer or a release layer is provided between a coloring material layer and a support layer in order to improve the film strength and thermal transferability of a thermal transfer recording medium. . In order to increase the sensitivity of the thermal transfer recording medium (allowing transfer with low energy) and to make it more compact, it is preferable that the film thickness be as small as possible, and research in this aspect has been conducted for a long time. However, when adopting an IVJtM structure with two or more layers, the allowable range of the film thickness of each layer becomes extremely narrow, and it is difficult to put it into practical use with the same design concept as in the case of a one-layer structure. Many attempts have been made to solve this problem, such as those disclosed in JP-A-59-224392 and JP-A-60-187593, using organic melt systems or real melt systems, but these efforts are still not fully satisfactory. However, coating film formation using water-based dispersants is a promising method in the future as it improves the working environment and reduces the cost of manufacturing equipment, but the type, amount, and surface activity of the carbon blank The properties of the film vary slightly due to the type and amount of the agent, the properties of the polymer dispersion, the temperature at which the film is formed, etc., and this is made even more difficult by adding the above-mentioned difficulty of the <2Ff!4 configuration. [Object of the Invention] An object of the present invention is to provide a thermal transfer recording medium that can perform transfer with 1 L energy and provides clear printing on both paper and smooth paper. [Structure of the Invention] As a result of intensive research, the inventors of the present invention found that in a thermal transfer recording medium having a plurality of layers with different compositions on a support, at least one set of adjacent two layers among the plurality of layers with different compositions is dispersed in an aqueous system. It has been found that the object of the present invention can be achieved by setting the dry film thickness of the layer formed from the composition and close to the support to a range of 0.5 μν (:1 to 3.5 μm Ja), and has accomplished the present invention. The present invention will be explained in more detail below.In the present invention, of the two layers with different compositions that are laminated, the layer closer to the support (hereinafter referred to as the heat-melt layer) has a heat-melt layer. It is preferable that the upper layer (hereinafter referred to as a thermoplastic layer) of the substance contains a thermoplastic polymer.The layer structure of the thermal transfer recording medium of the present invention can be shown in FIGS. 1 to 6. .Figures 1 to 6; ν1
1 is a support, 2 is a thermofusible layer, 3 is a thermoplastic layer, 4
indicates stinking prevention M, and 5 indicates adhesion 3!4 alignment. The colorant is preferably contained in the thermoplastic layer as shown in FIGS. 1 and 2, but may also be added in small amounts to the thermofusible layer as shown in PpJ3 and FIG. 4. Further, an adhesion adjusting layer may be provided as shown in FIGS. 5 and 6. The heat-melting substances used in the present invention include substances that are solid or semi-solid at room temperature, and whose melting point (Yanagimoto MI'
It is preferably a solid substance with a softening point (measured by Type J-2) or a softening point (measured by the ring and ball method) of 25 to 120°C, more preferably 40 to 120°C. Specific examples include carnauba wax, wood wax, auricula wax, vegetable wax such as esparto wax, beeswax, insect wax,
In addition to waxes such as animal waxes such as shellac wax and spermaceti wax, petroleum waxes such as paraffin wax, microcrystalline wax, ester wax, and oxidized wax, and mineral waxes such as montan wax, osichelite, and ceresin; Higher fatty acids such as phosphoric acid and behenic acid; palmityl alcohol, stearyl alcohol, behenyl alcohol, marnyl alcohol,
Higher alcohols such as myrinl alcohol and eicosanol; higher fatty acid esters such as cetyl palmitate, myricyl palmitate, cetyl stearate, and myricyl stearate; amides such as acetamine, propionic acid amide, palmitic acid amide, stearic acid amide, and amidowanx ; Etherm, T for ronomaleic acid, rosin phenol! I N, rosin derivatives such as hydrogenated rosin; 7-ethyl resin, terpene-based 4j (fat, xylene-based resin, low molecular weight styrene resin, 11' oil-based tj (II?
? , aromatic hydrocarbon resin, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, styrene-butadiene copolymer, styrene-ethylene-butylene copolymer, iophmer-based resin, polyamide-based Resin, polyester resin, Evokin resin, polyurethane resin, acrylic resin (fat, vinyl chloride resin, cellulose 431 flit, polyvinyl alcohol resin, styrene resin, imprene rubber, chloroprene rubber, natural rubber, etc.) Polymers such as sterylamine, behenylamine, palmitylamine, and other higher amines M are also described in JP-A-54-68253 [thermofusible solid components that are solid at room temperature] ], Japanese Patent Application Publication No. 1973-
105579 may be used. These thermofusible substances can be easily converted into water-based disvergicin and are preferably used. These thermofusible substances can be used alone or in combination of two or more. In the present invention, the composition ratio of the components forming the heat-fusible layer is not limited, but the total solid content of the heat-fusible layer is 100! l1j
It is preferable to use 10 parts by weight or more (more preferably 30 parts by weight or more) of the heat-melting substance based on part i. Further, a coloring material may be added to the heat-fusible layer as necessary. As for the coloring agent, the coloring agent described below can be used. The amount of colorant used is the total solid content of the heat-fusible layer! It is preferable that the amount is 20 parts by weight or less per 1i100 parts by weight. The heat-fusible layer of the present invention may contain the above-mentioned components and various additives. For example, vegetable oils such as castor oil, linseed oil, olive oil, animal oils such as whale oil, and mineral oils may be suitably used. Further, surfactants such as anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants are also preferably used. The heat-fusible layer of the present invention has a thickness of 0.5μ to 35μ, more preferably 1.5 to 3.0μ, even more preferably 1
．． The thickness may be 7 to 2.7 μm. The thermoplastic polymers used in the present invention include ester gum, rosin maleic acid resin, rosin 7enol F3
F fat, rosin derivatives such as hydrogenated rosin, phenolic resin, terpene resin, xylene type 0 (fat, petroleum resin, aromatic hydrocarbon resin, phionomer resin, polyester resin, polyamide resin, polyethylene resin) There are polypropylene resins, etc., which can be easily made into aqueous dispersions by known methods. Acrylic resins are more preferable polymers. 7L of mmJlc carboxylic acid or its ester and at least one copolymerizable monomer
Obtained by chemical polymerization. Examples of carboxylic acid moamers include methyl, ethyl, and acrylic acid or methacrylic acid.
Isopropyl, butyl, isobutyl, amyl, hexyl, octyl, 2-ethylhexyl, decyl, dodecyl,
Examples include hydroxyethyl and hydroxypropyl ester. Monomers that can be copolymerized include vinyl acetate, vinyl chloride, vinylidene chloride, maleic anhydride,
7-Maric anhydride, styrene, 2-methylstyrene, chlorostyrene, acrylonitrile, vinyltoluene, N-7
Examples include tyrolacryl 7mide, N-methylolmethacrylamide, N-butoxymethylacryl 7mide, N-butoxymethacrylamide, vinylpyridine, N-vinylpyrrolidone, etc., and one or more of these may be selected. Also preferred are diene-based fuborimers, such as emulsion polymers of tsene-based monomers such as butanoene, isoprene, imbutylene, chloroprene, and the above copolymerizable monomers, such as butadiene-styrene, butanoene-styrene-vinylpyricne, butadiene-7crylonitrile, Examples include chloroprene-styrene and chloroprene-acrylonitrile. Further, more preferred polymers include ethylene copolymers, such as ethylene-vinyl acetate, ethylene-ethyl acrylate, ethylene-methyl methacrylate, ethylene-isobutyl acrylate, ethylene-acrylic acid, ethylene-vinyl alcohol, and ethylene-chloride. Copolymers such as vinyl and ethylene-acrylic acid metal salts can be mentioned. Other thermoplastic polymers include polyurethane polymers and polyester polymers. In the present invention, the composition ratio of the components forming the thermoplastic layer is not limited, but the coloring agent may be 5 to 40 parts by weight (more preferably 5 to 3 parts by weight) with respect to 100 parts by weight of the total solid content of the thermoplastic layer.
5 parts by weight), and the thermoplastic material is preferably used in an amount of 5 to 95 parts by weight (more preferably 10 to 90 parts by weight). The thermoplastic layer of the present invention may contain various additives in addition to the above components. For example, vegetable oils such as castor oil, linseed oil, and olive oil, animal oils such as whale oil, and mineral oils may be preferably used, and anionic, cationic, nonionic, and amphoteric surfactants are also preferably used. The coloring agent used in the present invention is preferably carbon blank,
Any other inorganic pigment, organic pigment or organic dye may be used. Examples of inorganic pigments include titanium dioxide, zinc oxide, Prussian blue, cadmium ζ1AL, iron oxides and chromates of lead, zinc, barium and calcium. Examples of organic pigments include azo, thioinnovo, 7-thraquinone, anthonthurone, and tri-7-enedioxanone pigments, vat dye pigments, phthalocyanine pigments, such as copper-7 thalocyanine and its derivatives, and quinacridone pigments. Examples of organic dyes include oxidation dyes, direct dyes, disperse dyes, oil-soluble dyes, and metal-containing oil-soluble dyes. There are basically two ways to obtain a coating liquid by dispersing the thermoplastic ink containing the above-mentioned thermoplastic binder and colorant C) in water. For example, the following methods can be adopted. (a) After melting and kneading the thermoplastic binder dyeing colorant for 18 hours,
A method of dispersing in water containing a portion of surfactant, etc., if necessary. (b) Separately separate the thermoplastic binder and colorant into water containing a dispersant such as a surfactant as necessary.
A method of mixing these dispersions. (c) A method in which a thermoplastic binder is dispersed in water containing a dispersant such as a surfactant as required, and a colorant is added to the dispersion and mixed. Among these, method (b) is preferable. In the present invention, in addition to the above-mentioned components, an antifoaming agent, an agent for improving wetting with the heat-fusible layer, etc. may also be added. The support used in the thermal transfer recording medium of the present invention preferably has heat-resistant strength, dimensional stability, and surface smoothness. Examples of the material include punched paper, condenser paper, laminated paper, Paper such as coated paper, resin films such as polyethylene, polyethylene terephthalate, polystyrene, polypropylene, polyimide, etc., paper-resin film composites, metal coatings such as aluminum foil, etc. are all suitably used. The thickness of the support is generally about 60 μm or less, especially 1.5 μm to provide good thermal conductivity.
A shoulder thickness of ~15 μm is preferable. Furthermore, the thermal transfer recording medium of the present invention may optionally have a backing layer such as an anti-sticking layer on the back side of the support. In the thermal transfer recording medium of the present invention, techniques suitable for applying the constituent layers including the heat-fusible layer and the thermoplastic layer to a support such as a polymer film are known in the art.
These known techniques can also be applied to the present invention. h! containing, for example, a thermofusible layer and a thermoplastic layer! Constituent Layer The constituent layer, which is a layer formed by aqueous coating of an aqueous dispersion composition (latex), is applied using a reverse roll coater.
Any technique can be used, such as a method, an extrusion coater method, a gravure coater method, or a wire coater method. The thermoplastic layer of the present invention may have a thickness of 20 μm or less, more preferably 0°5 to 8 μs. The thermal transfer recording medium of the present invention may have other constituent layers such as an undercoat layer (for example, a layer for adjusting film attachment) and an overcoat layer. A method for thermal transfer recording using the thermal transfer recording medium of the present invention will be described below. The constituent layer surface of the thermal transfer recording medium of the present invention and a recording sheet such as ↑↑ are overlapped, and the thermal transfer recording medium 1 ( 1h' (When energy is applied from i and/or the recording sheet side, relatively low energy is applied to the thermoplastic layer, so that the colorant etc. are transferred to the recording sheet together with the thermoplastic substance. (Example) Below Examples are given below, but the embodiments of the present invention are not limited thereto.Eggplant; The term "1 part" used below refers to "parts by weight." Comparative Example 1 Polyethylene with a leakage of 3.5μ A solution with the following composition was applied onto the terephthalate film using a wire bar to a dry film thickness of 2.5 mm.
It was applied to form a μ shoulder to form a heat-fusible layer. Paraffin wax (161), 54℃) 9
Part ethylene-vinyl acetate copolymer (melt index 400 Softening point 88℃ Contains vinyl acetate ff120%> 1 toluene
90 parts Next, 10 parts of the following composition was dissolved and dispersed in 10 parts of toluene (dispersed for 24 hours in an Aspiration ball mill) to prepare a thermoplastic layer coating solution. Ester wax (74-80℃) 11?
IS ethylene-vinyl acetate copolymer (same as above) 2 parts acrylic resin (2-ethylhexyl methacrylate-methyl methacrylate copolymer molecule, i 20000) 16 parts partially disproportionated rono-modified resin 1 part carbon black Apply 3 parts of this coating solution to a dry film/72μ using a wire bar on top of the heat-melting 1
Apply it so that it crumbles, and apply it to the thermal transfer recording W water sample (S-1).
) was obtained. Next, a sample (S-2) was obtained in exactly the same manner except that the dry layer 17 of the heat-fusible layer was set to 3.7 μm. Example 1 A solution with the following composition was applied onto a 3.4μ shoulder polyethylene terephthalate film using a wire bar, and dried.
F11.5/7 g, 2.5# m OJ: C/3.0
/ja A thermofusible layer was formed. Paraffin wax water I/> dispersion (+n1+, 65℃)
80% (solid content equivalent) Ethylene-vinyl acetate copolymer (EV^) latex (
V^Content 2 15% (in terms of solid content) Polyethylene monobehenate moisture at (molecular weight of 1'lEG 4000) 4% (in terms of solid content) Surfactant 1% (in terms of solid content) Furthermore, the following composition Coat each of the above coating samples and dry for 115 minutes! )'J1, 5 μm thermal transfer recording medium samples (^-1), (8-2) and (8-:(
) was obtained. Carbon aqueous dispersion (3Q%) 16% (solid content equivalent)
2-Ethylhexyl acrylate-methyl methacrylate copolymer a body weight 65% (solid content ti-) EVA-based latex (V^ content 2 form 16% (solid content π) Surfactant 3% (solid content Conversion) Example Z A solution having the following composition was applied onto a polyethylene terephthalate film of 3 or 4 μm using a wire bar to form heat-fusible layers with dry film thicknesses of 2.2 μz, 2.5 μm, and 2.9 μm. Paraffin wax-7ionic surfactant (weight ratio 9:
1) Aqueous dispersion 84% (solid content) ethylene
Vinyl acetate copolymer (EV^) Latex Membrane 1
'72.1 μm thermal transfer recording medium sample (8-1), (
Rho 2) and (Rho 3) were obtained. Carbon black aqueous dispersion (30%) 16% (in terms of solid content $T.) 2-Ethylhexyl acrylate-methyl methacrylate-styrene copolymer latex 659/(in terms of solid content) [V-crystalline latex (containing V^) Content Type 2: 16% (in terms of solid content) Spreading agent: 3% (in terms of solid content) Comparative Example 2 The thickness of the heat-fusible layer of Example 2 was changed to 0.4μ and 3.6μ.
Two types of heat-sensitive transfer recording medium samples (S-3) and (S-4) were obtained in exactly the same manner except that they were made from skin. These thermal transfer recording medium samples were printed on a thermal printer (
Thin film serial head with heating element density of 7 dat/zz! The applied energy was 1.
Rough paper (Beck smoothness 10
2 seconds) and smooth paper (Beck smoothness 200 paper).
The results are shown in Table 1. Table 1 Print quality was evaluated visually on a three-level scale. ○・・・Reproduce clear alphabet Δ・・・
・・The reproduction of Alphabey) is a little unclear.
・As is clear from the table, the reproduction of the alphabet is unclear, only the heat-sensitive transfer recording medium sample having a heat-fusible layer in the V thickness range of the present invention gives good print quality on both rough paper and smooth paper. I understand that.

[Brief explanation of drawings]

Figure 1, Figure 2, Figure 3. Figures 14, 5 and 6 are
It is a ceremonial cross-sectional view seen in the thickness direction of the recording medium for explaining the structure of the thermal transfer recording medium according to the present invention. 1. Support 2... 8) Magnetic layer 3... Thermoplastic Layer 4... Sticking prevention 11:, /η5... Adhesion adjustment layer Applicant: Roku Konishi Photo Industry Co., Ltd. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] In a thermal transfer recording medium having a plurality of layers having different compositions on a support, at least one set of adjacent two layers among the plurality of layers having different compositions is formed from an aqueous dispersion composition, and a layer close to the support. 3. Dry film thickness of 0.5 μm or more.
A thermal transfer recording medium characterized in that the thickness is in the range of 5 μm or less.