JPS60166485A - Coating liquid for producing thermal transfer material - Google Patents

Abstract

PURPOSE:To obtain a coating liquid for producing a thermal transfer material which can be delt with safely and easily and can form a homogeneous thermally transferrable ink layer, by a method wherein a heat-fusible ink comprising a heat-fusible binder and a coloring agent is dispersed in water. CONSTITUTION:The weight ratio of the heat-fusible ink to water is generally in the range of 5/95-80/20, preferably, 15/85-60/40. In dispersing the ink in water, it is preferable to heat water to a temperature of not lower than 70 deg.C so as to facilitate dispersion, to use a surface active agent in an amount of 1-20 parts per 100 parts of the heat-fusible binder, and to set the particle side of the ink to be not larger than 10mum.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is safe and easy to handle, and can be coated on a support.
The present invention relates to a coating liquid for forming a heat-sensitive transfer material that can form a homogeneous heat-transferable ink layer by applying the following steps.

In recent years, with the rapid development of the information industry, various information processing systems have been developed, and recording methods and devices suitable for each information processing system have also been developed and adopted. As one of such recording methods, the thermal recording method has recently been widely used because it uses a light and compact device, is noiseless, and has excellent operability and maintainability.

However, among the recording papers used in thermal recording methods, ordinary thermal recording paper is a color-forming processed paper containing a color former and a color developer, so it is expensive, and records can be tampered with. The paper has disadvantages in that it has poor storage stability, such as the paper easily developing color due to heat or organic solvents, and the recorded image fading in a relatively short period of time.

In recent years, a thermal transfer recording method has been attracting particular attention as a method that maintains the advantages of the above-mentioned thermal recording method and compensates for the drawbacks associated with the use of thermal recording paper.

In this thermal transfer recording method, generally a sheet-like support 1
- using a heat-sensitive transfer material formed by forming a layer of heat-transferable ink made by dispersing a colorant in heat-melting paint,
This thermal transfer material is superimposed on a recording medium so that its thermal transferable ink layer is in contact with the recording medium, and heat is supplied from the support side of the thermal transfer material to the recording medium to transfer the melted ink layer onto the recording medium. By doing so, a transfer ink image is formed on the recording medium in accordance with the shape of heat supply. According to this method, it is possible to maintain the advantages of the thermal recording method described in ``-'' and to use paper as a recording medium, and also eliminate the disadvantages associated with the use of thermal recording paper described in ``1-''. .

In order to form a heat-transferable ink layer on the support, a method is generally used to melt-coat the heat-melt ink, which is made by dispersing a colorant in a heat-melt binder, onto the support. ing. However, in the case of Hot Melt Cold Resistant 71J, the temperature dependence of the coating liquid viscosity due to hot melt + 1 ink melting is generally high, and strict temperature control is required at high temperatures, and the heat transferable ink layer formed on the support. There is a problem in that it is difficult to control the layer thickness, especially the layer thickness when the layer is thin, and it is difficult to form a uniform thin layer of the thermal transferable ink layer. On the other hand, the viscosity of the coating liquid was lowered by dissolving or dissolving the heat-melting ink in an organic solvent to coat 1 g L, and then by evaporating the solvent, the heat-melt coating was Attempts have also been made to eliminate the inconvenience. However, in this case, there are problems such as the danger of fire due to the organic solvent used, interference with the occupational safety of workers, and environmental pollution.

In view of the above circumstances, an object of the present invention is to provide a coating liquid for forming a thermal transfer material that is safe and easy to handle and capable of forming a homogeneous thermal transferable ink layer.

According to the research of the inventor, it is extremely effective to form a coating liquid in which a heat-melting ink composition is dispersed in water in order to achieve the above-mentioned purpose. was confirmed. In other words, such water-dispersed coating liquids have low viscosity and can be applied virtually at room temperature, which not only eliminates the need for temperature control at high temperatures that is required for hot-melt coating. By removing moisture after coating tIi, a thin layer of the thermally transferable ink layer can also be formed with high precision. In addition, since no organic solvent is used to reduce the viscosity, problems such as fire danger, deterioration of the working environment, and exhaust pollution caused by organic solvents do not occur.

The coating liquid for forming a thermal transfer material of the present invention is based on two series of findings.More specifically, it is a coating liquid for forming a thermal transfer ink layer by coating on a support. It is characterized by being made by dispersing a heat-melt ink consisting of a heat-melt binder and a colorant in water.

The present invention will be explained in more detail below. In the following description, "%" and "parts" representing weight ratios are important criteria unless otherwise specified in 4.).

The heat-melting ink that provides the coating liquid for forming a heat-sensitive transfer material of the present invention is basically the same as that constituting the heat-transferable ink layer in a conventional heat-sensitive transfer material. The main components are a heat-melting binder and a coloring agent.

Heat-melting binders include waxes such as carnaupa wax, paraffin wax, satur wax, microcrystalline wax, and castor wax; stearic acid, palmitic acid, lauric acid, aluminum stearate, lead stearate, and stearic acid. Derivatives such as higher fatty acids such as helium, zinc stearate, zinc palmitate, methyl hydroxystearate, glycerol monohydroxystearate or their metal salts and esters; polyethylene, polypropylene, polyisobutylene, polyethylene wax, polyethylene oxide,
Thermoplastic resins made of olefins alone or copolymers, or derivatives thereof, such as polytetrafluoroethylene, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, etc. , etc. are used. These heat-melting pinters may be used alone or in a mixture of two or more.

Colorants include carbon black, nigrosine dye,
Lamp black, Sudan black SM, alkali blue, first yellow G, benzidine yellow, pigment
Yellow, India First Orange, Dolphin Red, Paranitroaniline Red, Toluidine Red, Carmine FB, Permanent Bordeaux FRR, Pigmen 1...Orange R, Lysol Lend 20, Lake Red C, Rhodamine FB, Rhodamine B rake,
Methyl Biolev 1- B Lake, Phthalocyanine Blue, Pigment Blue, Brilliant Green B
, Phthalocyanine Green, Oil Ixa-GG, f Bon and First Yellow CGG, Kayaset Y963, Kayase, l-Y G, Sumiplast and Yellow GG, Zapon Fast Orange RR, Oil Scarlent, Sumiplast Orange G, Orasol Brown B , Pomelo First Scarlet L-CG, Eisenspiron Lent, BEH, Oil Pink OF, Victoria Blue F4R177-Sigemple-5007, Sugun Blue, Oil Peacock Blue, etc. All known dyes and pigments can be used. can.

Coating 1 (i
The method for obtaining the liquid is basically arbitrary, and for example, the following methods can be employed.

(a) After melt-kneading the hot-melt binder and colorant,
A method of dispersing in water containing a dispersant such as a surfactant as necessary; (b) A method of dispersing the heat-melting binder and colorant separately in water containing a dispersant such as a surfactant as necessary. (c) A method of dispersing a hot-melt binder in water containing a dispersant such as a surfactant as necessary, and adding a colorant to the dispersion and mixing. .

During dispersion, it is preferable to heat the water to 70°C or higher to facilitate the dispersion of the hot-melt ink, and add about 1 to 20 parts of a surfactant per 100 parts of the hot-melt paint. It is preferable that the particle size of the heat-melting ink to be dispersed is 10p or less. As the surfactant, any of anionic, cationic, amphoteric, and nonionic surfactants can be used. In addition, when explaining the reason, for example, a propeller,
Usual dispersing machines such as stirring blades such as turbine blades, homogenizers, colloid mills, attritors, and ultrasonic mixers are used. The ratio of heat-fusible ink to water is usually from 5/95 to 80/20, preferably from 15/85 to 60/40.

In addition to the components listed in L, an antifoaming agent, an agent for improving wetting with the support, etc. can also be added to the coating solution of the present invention.

The coating solution of the present invention thus obtained is coated on a support and dried at 105°C for 10 minutes to a thickness of 0.5 to 30-1, preferably 1. A heat-sensitive transfer material is obtained by forming a heat-transferable ink layer in steps 1 to 20.

As the support, conventionally known films and papers can be used as they are, such as relatively heat-resistant plastic films made of polyester, polycarbonate, triacetyl cellulose, nylon, polyimide, etc.
Cellophane or parchment paper can be suitably used. The thickness of the support is preferably about 2 to 15 microns when considering a thermal head as a heat source for thermal transfer, or a heat source such as a laser beam that can selectively heat the thermal transferable ink layer is used. There are no particular restrictions when doing so. In addition, when using a thermal head, a heat-resistant protective layer made of silicone resin, fluororesin, polyimide resin, epoxy resin, phenol resin, melamine resin, nitrocellulose, etc. should be provided on the surface of the support that comes into contact with the thermal head. This makes it possible to improve the heat resistance of the support, or to use a support material that could not be used conventionally.

The method for coating the coating liquid of the present invention on a support is as follows:
Methods such as plate coating, spray coach ink, roll coach ink, rod coat ink, and gravure coating may be used as appropriate.

As explained in detail above, according to the present invention, a thermofusible ink consisting of a thermofusible binder and a colorant,
By dispersing it in water, it is safe and easy to handle.
A coating liquid for forming a heat-sensitive transfer material that can form a homogeneous thin heat-transferable ink layer is provided.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

[Kneaded cocarbon blank of thermal transferable ink composition] 15 parts Paraffin (m260-65°C) 50 /1 Carnaupa wax 20 // Ethylene-vinyl acetate copolymer 15 // (Ethylene/
Vinyl acetate = 90/10)'' Each component was heated and dispersed using 7 triters to obtain a kneaded product.

[V-formation of thermal transfer ink composition dispersion and thermal transfer material] 90 parts of the kneaded material obtained above and polyoxyethylene (7 parts)
After melt-mixing 10 parts of stearyl ether (mol) at 90°C, add 3 parts of hot water at 90°C while stirring with a homomixer.
00 parts were added gradually. After the addition was completed, the mixture was kept at 90°C, stirred for an additional 15 minutes using a homomixer, and cooled to room temperature to obtain a water-dispersed @ dilute solution. Tokukai Sho GO-IG6485
(4) Apply this coating solution to a hexagonal polyethylene terephthalate film using a wire parser so that the dry coating thickness is 0 degrees, and heat it for 10 minutes in a hot air dryer at 105°C. A thermally transferable ink layer was formed by drying.

When a printing test was carried out using the heat-sensitive transfer material thus obtained using a thermal transfer printing device of a Japanese word processor (Kano Word 45), clear printing was obtained.

Aqueous dispersion-8 was obtained in the same manner as in Example 1, except that the composition mentioned in [Kneading of thermal transfer ink composition] in Example 1 was as follows. .

Paraffin (m260-65°C) 60 parts Carnauba wax 25 l/Ethylene-vinyl acetate copolymer 15//(ethylene/
(Vinyl acetate = 90/10) 20 parts of carbon black, 6 moles of polyoxyethylene, and 8911 nonylphenyl ether water were mixed and dispersed in a Zantomir to obtain an aqueous dispersion-B.

80 parts of the aqueous dispersion-A and 20 parts of the aqueous dispersion-B are uniformly mixed, and the resulting coating liquid is applied to polyethylene terephthalate 1: of thickness 6 in the same manner as in Example 1, A thermal transfer material having a thermal transfer layer with a thickness of 10 μm was obtained.

Regarding this thermal transfer material, the same printing test I as in Example 1 was carried out.
When I did this, I was able to get an explanatory printout.

Claims (1)

[Claims] Heat melt+! 1. A coating liquid for forming a thermally transferable ink layer by coating on a support, the coating liquid being formed by dispersing a heat-melting ink consisting of a binder and a colorant in water.