JPS63153190A - Thermal transfer recording method - Google Patents

Abstract

PURPOSE:To enable recording by using a film provided only with a heat-fusible ink layer without using a base film and contrive a reduction in cost, by using a thermal transfer recording medium which comprises an ink contained in a base constituted of a microporous resin structure, the ink comprising a heat- fusible substance being solid at normal temperature and a coloring agent as main constituents. CONSTITUTION:A thermal transfer recording medium, for example, a thermal transfer ribbon 1 is used which comprises an ink contained in a base constituted of a microporous resin structure 4, an ink comprising a heat-fusible substance 3 and a coloring agent 2 as main constituents being contained in said micropores. The ribbon 1 and an image-receiving material, e.g., a recording paper 6 are laid on each other, a heat-resistant film 7 is laid on the opposite side, and heat is applied to the ribbon 1 by a thermal head 5 through the film 7. As a result, the ink contained in the microporous resin structure 4 is melted, and exudes from the pores, whereby an image according to a signal is transferred onto the recording paper.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a thermal transfer recording method for transferring a recorded image by heating a recording medium.

[Conventional technology 1] In recent years, non-impact printing technology has been researched as terminal equipment for OA and A+A, which is rapidly declining.
Among them, the equipment is easy to maintain and operate, and it is also inexpensive.
Thermal transfer recording methods are considered promising because they can be miniaturized.

However, the current thermal transfer recording method uses a thermal transfer sheet, and once this sheet is used, it has to be completely drained even if there are parts that do not print, so the high cost of consumables has always been a problem. There is.

Therefore, thermal rheography is a method that does not use the thermal transfer sheet described above, in which semi-solid ink is heated and melted with a porous thermal head, and the ink is transferred to recording paper through ink passage holes in a heating element to form an image. Although methods have been proposed, they are currently not put into practical use due to problems with image quality and recording speed.

By the way, in conventional thermal transfer sheets, the support film is more expensive than the ink layer, and accounts for half of the [Ii] of the sheet. Therefore, attempts were made to create a thermal transfer sheet that did not have this support, but this sheet was mainly composed of wax and had a small amount of resin, so it had low mechanical strength, and after thermal transfer, holes formed where the ink was transferred. This further weakened the sheet, causing problems such as tearing of the sheet and sticking of the head.

In order to solve the above problem, a sheet with increased resin content was proposed, but although the mechanical strength was improved, the thermal transfer recording sensitivity decreased, and the thermally transferred areas still had holes and stuck to the head. The problem that occurred could not be resolved.

[Purpose] The present invention solves the above-mentioned problems of the prior art and provides a thermal transfer recording method in which a thermal transfer recording medium without a support film can be used multiple times, with the aim of reducing consumable costs in the thermal transfer recording method. This is what we are trying to provide.

[Structure] The structure of the present invention for achieving the above object is that an ink whose main components are a heat-fusible substance that is solid at room temperature and a coloring agent is contained in a substrate made of a microporous resin structure. A thermal transfer recording method in which a thermal transfer recording medium and an image receptor are stacked on top of each other, and the recording medium is heated with a thermal head or the like from the opposite side of the image receptor through a heat-resistant film that is separate from the recording medium. It is.

To explain specifically with reference to the drawings, as shown in FIG. 1, the present invention uses a microporous resin structure 4 as a base material, and contains a heat-fusible substance 3 and a coloring agent 2 as main components in the pores. A thermal transfer recording medium, for example, a thermal transfer ribbon 1 containing an ink having the following properties is used.

This thermal transfer ribbon 1 and an image receptor, for example, a recording paper 6 are placed on top of each other, a heat-resistant film 7 is placed on the opposite side, and the thermal head 5 is used to transfer the thermal transfer ribbon 1 through the heat-resistant film 7.
heat up. In this way, the ink in the microporous resin structure 4 melts and oozes out from the pores, thereby transferring an image corresponding to the signal onto the recording paper.

In order to improve heat conduction from the thermal head 5 to the thermal transfer ribbon 1, it is preferable to adopt the following means.

(1) In order to improve the contact between the heat-resistant film 7 and the thermal transfer ribbon 1, an oil that does not damage these materials is applied to the surface of the heat-resistant film 7. Such oil may include, for example, cottonseed oil. ,rapeseed oil,
These include animal oils such as whale oil, and mineral oils such as motor oil, spindle oil, and dynamo oil.

(2) A material with high thermal conductivity, such as metal powder, alumina, carbon black, etc., is blended into the material of the heat-resistant film 7 or coated on the surface of the heat-resistant film.

(3) In order to increase the printing pressure of the thermal head and to improve the adhesion between the heat-resistant film 7 and the thermal transfer ribbon 1, a thermal head 5 having a convex tip is used.

In addition, in order to use the heat-resistant film 7 multiple times, the heat-resistant film 7 may be formed into a belt shape as shown in FIG. 2, and the belt may be circulated by a pulley 10.

In order to remove stains on the heat-resistant film 7 due to cyclic use,
For example, it is preferable to provide a rubber roller, a sponge roller soaked with a solvent, or a fur brush 9.

The thermal transfer ribbon 1 is also wound onto the reel 11, and when one reel becomes empty, the reel can be used multiple times by reversing the reel.

It is preferable to arrange a platen roller 8 on the back side of the image-receiving paper so that the pressing force from the thermal head 5 can reliably act on the heat-resistant film 7, the thermal transfer ribbon 1, and the recording paper 6.

Further, instead of the thermal head 5, signal heating may be performed using a laser beam.

The manufacturing method and materials for the thermal transfer recording medium of the present invention, that is, the thermal transfer sheet, will be described in detail below.

That is, heat-fusible substances and coloring agents, and oil that serves to form porosity in the resin are mixed and dispersed together with an appropriate organic solvent using a dispersion device such as an attritor or a ball mill. Obtain a dispersion (or a solution). Separately, a solution of a thermoplastic resin dissolved in an organic solvent is obtained, mixed with the ink dispersion, and uniformly dispersed using a mixer such as a ball mill. Next, the obtained dispersion is applied onto a support with a smooth surface (for example, a glass plate) and dried to obtain a hot-melt ink layer with the above-mentioned fine structure, which is peeled off to form a film. is obtained, which becomes the thermal transfer recording medium of the present invention.

A wetting agent, a dispersing agent, etc. may be added to the dispersion liquid in order to improve the dispersion of the heat-fusible material, colorant, and oil.

Also, if necessary, fillers commonly used in resin coatings of this type can be added.

The resins constituting the microporous resin structure include vinyl chloride, vinyl acetate, vinylidene chloride, nitrocellulose, cellulose butyrate, cellulose acetate, acrylic acid, methacrylic acid, acrylic ester and It is preferable to use thermoplastic resins such as single or copolymers of methacrylic acid esters, and thermosetting resins such as phenol, furan, formaldehyde, urea, melamine, alkyds, unsaturated polyesters, and epoxy. .

Further, from the viewpoint of skeleton durability and film formability, the amount of the heat-resistant microporous resin is preferably 50% by weight or more of the entire heat-sensitive transfer sheet.

In addition, after manufacturing the thermal transfer sheet, to prevent background stains,
It is also possible to remove oil and coloring agent adhering to the surface of the sheet by washing with a solvent or the like.

As the heat-melting substance that is solid at room temperature and used as an ink component in this invention, heat-melting binders that constitute heat-melting ink in ordinary heat-sensitive transfer recording media can be used, such as carnauba wax and paraffin wax. , Sasol wax, microcrystalline wax, castor wax, and other waxes; stearic acid, palmitic acid, lauric acid, aluminum stearate, lead stearate, barium stearate,
Higher fat M such as zinc stearate, zinc palmitate, methyl hydroxystearate, glycerol monohydroxystearate or derivatives thereof such as metal salts and esters; polyethylene, polypropylene, polyisobutylene, polyethylene wax, oxidized polyethylene, polytetrafluoride Thermoplastic resins made of olefins such as ethylene, ethylene-acrylic acid copolymers, ethylene-ethyl acrylate copolymers, ethylene-vinyl acetate copolymers, and other olefins alone or copolymers or derivatives thereof are used. These holding materials are used alone or in a mixture of two or more at a ratio of 50 to 200 parts per 100 parts of the thermoplastic resin constituting the thermal transfer layer.

As the pore-forming auxiliary oil, any liquid, semi-solid, or heat-melting solid may be used as long as it is incompatible with the above-mentioned thermoplastic resin and is non-volatile. As liquid retaining materials, for example, animal and vegetable oils such as cottonseed oil, rapeseed oil, and whale oil; or mineral oils such as motor oil, spindle oil, and dynamo oil are used; as semisolid carriers, for example, lanolin, lanolin derivatives, petrolatum, lard, etc. are used. .

This oil is preferably the above-mentioned lanolin derivative oil, more preferably an oil of lanolin fatty acid or lanolin fatty acid ester, and specific examples thereof include Neocoat 0ES-181, 0ES-183,
Examples include LFC-50M and LS-3102MB (all manufactured by Yoshikawa Oil Co., Ltd.).

Although these may be contained in an amount of 20% by weight or more, it is also possible to add a low-viscosity oil having a viscosity of 300 cps or less in consideration of lowering the viscosity.

Specific examples of the coloring agent include the following.

Coloring dyes and color pigments may be used, but dyes can provide images with more preferable gradation.

Specifically, the colored dyes used in this invention include the following direct dyes, acid dyes, basic dyes, mordant dyes, sulfur dyes,
There are vat dyes, azoic dyes, oil dyes, heat sublimable disperse dyes, etc.

1) Direct dyes: Direct Sky Blue, Direct Black W, etc.

2> Acidic dye: Tartrazine, Acid Violet 6
81 Acidophore 3G etc.

3> Basic dyes: safranin, auramine, crystal violet, methylene blue, rhodamine B1 Victoria blue B, etc.

4> Mordant dye: Sunchromine Fast Blue-MB, Elio from Azurol B, Alizarin Yellow B, etc.

5) Sulfur dye: Sulfur Brilliant Green 4G, etc.

6) Vat dyes: indanthremble, etc.

7) Azoic dyes: naphthol As, etc.

8) Oil dye: Nigrosine, Spirit Black EB,
Varifast Orange 3206, Oil Black 215
, Butter Yellow, Sudan Blue ■, Oil Red B
, Rhodamine B et al.

9) Heat-sublimable disperse dye (9-1) Monoazo disperse dye: Daybirds First Yellow 01 Daybirds First Yellow 5G1
Daybird's First Yellow 5R, Daybird's Red R, etc.

(9-2) Anthraquinone disperse dye; Disperse 1-st Violet OR, Disperse Fast Violet B1 Disperse Blue Extra, Disperse First Brilliant Blue B, etc.

(9-3) Nitrodiphenylamine-based disperse dyes: Disbird's Fast Yellow RR, Disbird's Fast Yellow GLW.

These dyes are preferably in a dissolved state.

Examples of colored pigments include colored fine particle pigments and monoazo pigments.

Specific colored fine particle pigments are shown below. All are made by Hoechst, and the color index numbers are shown in parentheses.

Permanent Yellow GG, 2 (Pigment Yellow 17), Permanent Yellow D HG Trans 02
(Pigment Yellow 12), Novo Palm Yellowt (RO3 (Pigment Yellow 83), Hansa Brilliant Yellow 50XO2 (Pigment Yellow 74), Permanent Orange RLOI (Pigment Orange 34), Novo Palm Red HFG (Pigment Orange 38), Novo Palm Red HFT ( Pigment Red 175), Permanent Lake Red LCLLO2 (Pigment Red 53:1), Novopalm Red HF4B (Pigment Red 187),
Permanent Carmine FBBO2 (Pigment Red 146), Permanent Lupine L6B (Pigment Red 57:1), Hostapalm Pink Hytrans (Pigment Red 122), Reflex
Blue R50 (Pigment Blue 61) Examples of monoazo pigments include compounds represented by the following structural formula.

X-N=N-Y however, X didiazonium salt residue Y: coupler residue In particular, specific examples of product names include the following.

(1) 5ico Fast Yellow D 13
55 (made by BASF) (2) 5ico Fast
Yellow D 1250 (made by BASF F) (3)
The structural formula of Lake Red LC (manufactured by Hoechst) is (4) Lake Red C405 (manufactured by Dainichiseika) (
5) Fast Red 1547 (manufactured by Dainichiseika)
The structural formula is: In order to further improve the gradation obtained by the present invention, it is also possible to add a gradation control agent to be described later.

In other words, the gradation control agent has better wetting and compatibility with the resin than low melting point materials such as oil and wax, which are the main components of hot melt ink, and is firmly held in the sponge resin structure, making it porous. It appears to be possible to delicately control the pore size of the tissue to make it smaller. Therefore, even when thermal energy is applied, it is not transferred out, but is retained in the porous structure, and acts as a good gradation control agent by controlling the transfer of colorants and ink existing around it. it is conceivable that. In addition, by adding a gradation control agent, the unevenness of the surface increases, the contact point with the receptor becomes smaller, and the effect of preventing background smearing can be cited.

As the gradation control agent, the following are shown as specific examples.

1) Acicular crystal pigment (Japanese Patent Application No. 60-38868) 2) Azo pigment (Japanese Patent Application No. 60-192098) 3) Phthalocyanine pigment (Japanese Patent Application No. 60-168562) Addition of the above gradation control agent Excellent is 0.5 per part by weight of dye
~10 parts by weight, preferably 1 to 5 parts by weight.

Hereinafter, the present invention will be specifically explained with reference to Examples. Note that the amounts (parts) of each component described in the Examples are parts by weight.

Example 1 Colorant: Neozapon Blue 807 (BA
SF) 10 parts Carnauba wax N0.1 (Noda Wax) 15 parts Lanolin fatty acid oil (OES-183, Furukawa Oil)
10 parts dispersant 0.5 parts liquid paraffin 3 parts 90 parts of the above hot melt ink components
The mixture was thoroughly dispersed in a ball mill for about 48 hours with a mixed solution of 100 parts of methyl ethyl ketone and 130 parts of toluene at .

Then 20% by weight of cellulose acetate butyrate C
A8381-0.5 (Eastman Chemica
llJm, 0.155-165°C) solution (10 parts resin, 20 parts toluene, 20 parts methyl ethyl ketone) 300
The mixture was added to the above ink dispersion and dispersed in a ball mill for about 1 hour to prepare a coating of a heat-sensitive transfer composition.

This paint was coated onto a smooth glass plate using a wire bar, dried at a drying temperature of 100° C. for 1 minute, and peeled off to prepare a thermal transfer sheet with a thickness of about 10 μm.

The transfer film thus obtained was sandwiched between a 6 μm thick heat-resistant polyester film and plain paper as a receiver, and the heating energy was changed from the back side of the heat-resistant film using a printer with a commercially available serial thermal head. When an image was recorded using the same method, a clear cyan-colored printed image could be obtained.

Example 2 Coloring agent: Kayaset Black G (manufactured by Nippon Kayaku) 10 parts Carnauba wax No. 1 (manufactured by Noda Wax) 10 parts Lanolin fatty acid oil (OES-183) 20 parts Powder 0.5 parts Liquid paraffin 3 parts Top When a thermal transfer sheet was prepared using the above heat-melting ink valve in the same manner as in Example 1 and an image was recorded, a clear black printed image could be obtained.

Example 3 Colorant: Neozapon Red 365 (BA
SF) 10 parts Carnauba wax N0.1 (Noda Wax tA) 15 parts Lanolin fatty acid oil (OES-183, Furukawa Oil) 10 parts Powder
0.5 part liquid paraffin
3 parts of the above heat-melting ink component is subjected to quantum dispersion at 90° C. for about 48 hours with a mixed solution of 100 parts of methyl ethyl ketone and 130 parts of toluene in a ball mill.

Then 10% by weight of vinyl chloride vinyl acetate copolymer V Y H)-
1 (manufactured by Union Carbide) solution (10 parts of resin, 30 parts of toluene, 60 parts of methyl ethyl ketone) 500
The mixture was added to the above ink dispersion and dispersed in a ball mill for about 1 hour to prepare a coating of a heat-sensitive transfer composition.

This paint was coated on a smooth glass plate using a wire bar, dried at a drying temperature of 100° C. for 1 minute, and peeled off to prepare a thermal transfer sheet with a thickness of about 12 μm.

The transfer medium thus obtained was sandwiched between a 7.5μ thick heat-resistant polyimide film and plain paper as a receiver, and then heated using a printer with a commercially available serial thermal head from the back side of the heat-resistant film. When we recorded an image by changing the color, we were able to obtain a clear red printed image.

[Effects] As is clear from the above explanation, the heat-sensitive recording method of the present invention aims to reduce the cost (about 172 mm compared to the conventional cost), and uses heat-melting ink without using a support film, which has traditionally been a factor in high costs. It made it possible to record using a layer-only film, and by using this it was possible to obtain printed images almost the same as those of conventional thermal transfer sheets.

In addition, by selecting various colorants, multicolor images can be created in 1n
You can also

[Brief explanation of the drawing]

FIG. 1 is an enlarged schematic cross-sectional view of a transfer section when carrying out the method of the present invention, and FIG. 2 is an explanatory diagram showing one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Thermal transfer ribbon, 2...Colorant, 3...Thermofusible substance, 4...Fine porous resin structure, 5...Thermal head, 6...Recording paper, 7...・Heat-resistant film, 8...Platen roller, 9...Rotating brush, 1
0...Pulley, 11...Reel. Patent applicant Rico Co., Ltd. - Agent Patent attorney Hide Komatsu Agent Patent attorney Hiroshi Asahi Figure 1 Figure 2

Claims (1)

[Claims] A thermal transfer recording medium containing an ink whose main components are a heat-fusible substance and a colorant that are solid at room temperature is placed in a substrate having a microporous resin structure, and an image receptor is layered on the image receptor. is a thermal transfer recording method characterized in that the recording medium is heated from the opposite side with a thermal head or the like through a heat-resistant film that is separate from the recording medium.