JPS6239292A - Thermal transfer material - Google Patents

Abstract

PURPOSE:To enable an efficient energy-saving thermal transfer recording and enable to cope with high-speed printing, by constituting a base of an aromatic polyamide film comprising a fine heat-conductive powder, in a thermal transfer material having a thermally transferable ink layer on a base. CONSTITUTION:The base is constituted of an aromatic polyamide film comprising a fine heat-conductive powder. The thickness of the film is preferably 0.5-20mum, more preferably, 1-6mum. The fine heat-conductive powder is preferably a fine carbon powder having favorable thermal conductivity, such as carbon black, lamp black, graphite, acetylene black and Ketjen black, or a fine powder of a highly heat-conductive metal such as aluminum, nickel, copper, tin, titanium and Fe. By using a highly heat-resistant base, it is possible to enhance applied thermal energy even where the base is thin. In addition, because the fine heat- conductive powder is incorporated in the base, heat-transmitting efficiency is favorable, while favorable transfer can be achieved, and high-speed printing can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a thermal transfer material that is capable of efficient and energy-saving thermal transfer recording, and is dust-free and compatible with high-speed printing.

[Conventional technology]

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. One such recording method is the thermal recording method.
The equipment used is lightweight, noiseless, and has excellent operability and maintainability, and has recently been widely used.

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 being easily colored by heat or organic solvents, and the recorded image fading in a relatively short period of time.

Thermal transfer recording method has recently been attracting particular attention as a method that maintains the advantages of the above-mentioned thermal recording method and compensates for the flaw in the use of thermal recording paper.

This heat-sensitive transfer recording method generally uses a heat-sensitive transfer material in which a heat-transferable ink layer consisting of a heat-melting binder and a colorant dispersed thereon is coated on a sheet-like support. The thermal transfer material is superimposed on the 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 to the recording medium. By transferring, a transferred ink image is formed on the recording medium in accordance with the heat supply shape (cutane) K. According to this method, the above-mentioned advantages of the thermal recording method are maintained, and the ink image can be printed on plain paper. can be used as a recording medium.1
), it is possible to eliminate the disadvantages of using the above-mentioned heat-sensitive recording paper.

Conventional thermal transfer materials are made by coating a polyethylene terephthalate film (hereinafter abbreviated as PET film) with heat-melting ink. In addition, attempts have been made to make PET film thinner in order to save energy during transfer. In addition, in order to perform high-speed printing, attempts have been made to shorten the application/4 pulse period and increase the thermal energy applied per unit time so that heat is applied in a short period of time to melt the hot-melt ink.

However, conventionally used PET film has a heat deformation temperature of 240°C and a continuous heat resistance temperature of 150°C. If the thickness of the material is reduced to, for example, 6 μm or less, and the surface temperature is increased by increasing the heating energy applied per unit time, the PET film will melt and holes will be formed, and the thermal head and the PET film will melt. This had the disadvantage of causing poor running performance.

[Problems to be solved by the invention]

The present invention has been made to provide a thermal transfer material that solves the conventional problems, further improves the efficiency of heat transfer to the ink layer, and enables high-speed printing.

[Means for solving problems]

That is, the thermal transfer material provided by the present invention has a thermal transferable ink layer on a support, and is characterized in that the support is made of an aromatic polyamide film containing thermally conductive fine powder. It is something to do.

[Detailed description and examples of the invention]

The present invention will be explained in more detail below. In the following, "parts" or "chi" are based on weight unless otherwise specified.

The aromatic polyamide film used in the present invention basically has a basic skeleton of the general formula % (where Ar and Ar' each represent an arylene group such as an optionally substituted phenylene group).・The main component is a structural unit represented by ), where n represents the degree of polymerization. It can be obtained from a combination of cyamine, diisocyanate and nocaldic acid by interfacial polycondensation method, low temperature solution polymerization method, etc.

Specific examples of the structural unit of the general formula include the following.

X Y (However, X and Y each represent a hydrogen atom, a -rodane atom, an alkyl group having 1 to 20 carbon atoms, a nitro group, or a phenyl group.) In addition, the aromatic polyamide film used in the present invention includes: In addition to one or more of the above basic skeletons, it may contain a sulfone bond or an ether bond. Further, in addition to the amide bond found in the basic skeleton, it may contain a urea bond or an imide bond.

The thickness of the aromatic polyamide film used in the present invention is 0.
．． It is preferably 5 to 20 μm, more preferably 1 to 6 μm.

The thermally conductive fine powders used in the present invention include carbon fine powders such as carbine black, lamp black, graphite acetylene black, and Ketjen black, which have good thermal conductivity, and aluminum, dichloride, and copper which have high thermal conductivity. , tin, titanium, Fe, and other metal fine powders are preferably used. Furthermore, fine powder of gold octoxide, carbide, nitride, etc., which has high thermal conductivity, is used. The average particle size is 5.
The thickness is preferably .mu.m or less, more preferably 0.5 .mu.m or less, and even more preferably 100 milli.mu.m or less.

The content of the thermally conductive fine powder is preferably in the range of 5% to 50% of the film, and less than 5% is expected to have a weak effect.
If it exceeds this value, the breaking strength of the base material will be too weak for practical use.

In order to produce an aromatic polyamide film containing a thermally conductive fine powder, an interfacial polycondensation method is used, for example, from acid halide and cyamine, which is obtained by mixing a conductive fine powder into a film coating solution. The obtained aromatic polyamide is dissolved in an amide solvent such as dimethylformamide or N-methylpyrrolidone, and thermally conductive fine powder is mixed therein.
It can be obtained after casting and stretching.

' The heat-fusible ink layer provided on the aromatic polyamide film containing thermally conductive fine powder mainly contains a heat-fusible binder and a colorant, and examples of the heat-fusible binder include carnauba wax, paraffin wax, sasolwa,
Waxes such as wax, microcrystalline wax, castor wax, nistearic acid, palmitic acid, lauric acid, aluminum stearate, lead stearate,
Higher fatty acids such as barium stearate, zinc stearate, zinc palmitate, methyl hydroxystearate, glycerol monohydroxystearate or their metal salts, derivatives such as esters, polyamide resins, polyester resins, extremely high molecular weight epoxy resins Vinyl resin rings, including polyurethane resins, polyacrylic resins (e.g. polymethyl methacrylate, polyacrylamide), polyvinylpyrrolidone, etc., polychlorinated resins? vinyl-based resins (e.g., vinyl chloride-vinylidene chloride copolymer, chloride-vinyl acetate copolymer, etc.) 2cellulose, methylcellulose, ethylcellulose, carboxymethylcellulose, etc.) #polyvinyl alcohol-based resin (e.g., polyvinyl alcohol,
partially saponified polyvinyl alcohol, etc.).

Petroleum resin, rosin derivative, coumaron-indene resin,
Terpene resin, novolak type phenolic resin, polystyrene resin, 4? Lyolefin resins (e.g. polyethylene, polypropylene).

polypuden, ethylene-vinyl acetate copolymer, etc.).

Examples include polyvinyl ether resins, polyethylene non-glycol resins, elastomers, natural rubber, styrene-butadiene rubber, isogrene rubber, and the like. Further, these components are appropriately mixed and used in such a manner that the softening temperature of the heat-melting binder falls within the range of 40°C to 150°C, preferably iso°C to 140°C. In addition to the above-mentioned waxes and resins, additives such as surfactants and plasticizers may also be used. The softening temperature referred to herein is determined as the outflow starting temperature when measured using a Flow Tester CFT 500 manufactured by Takashuma Seisakusho under the conditions of a load of 10 kg and a temperature increase rate of 2° C./min.

As the colorant, all of the various dyes and pigments used in the fields of printing and recording can be used. These colorants are usually preferably used in a proportion of 3 to 300 parts by weight per 100 parts by weight of the heat-melting binder.

In order to obtain the heat-sensitive transfer material of the present invention, the above-described heat-melting binder, colorant, and additives are melt-kneaded using a dispersion device such as an attritor, or kneaded with an appropriate solvent, and heated. Is it possible to obtain meltable, solution or dispersion inks, and to prepare these inks with aromatic inks containing thermally conductive fine powder?
It may be formed by coating it on a Lyamide film and drying it if necessary.

The planar shape of the thermal transfer material of the present invention is not particularly limited, but it is generally used in the form of a tie-bright printer or a wide tape used in line printers. Further, for color recording, a heat-sensitive transfer material can be used in which heat-melting ink of several different tones is applied in a striped or striped pattern. A more detailed example will be explained below using Examples.

Example 1 <Formulation 1> Ink 1 was prepared by dispersing each component of the above formulation by heating it to 130° C. and mixing it in a Sunto Mill for 30 minutes to disperse Shi, Carginira, and Ri.

After dehydrochlorinating and neutralizing the aromatic polyamide obtained from P-phenylenediamine and isophthalic acid chloride in N-methylpyrrolidone, 15% N
- Make a methylpyrrolidone solution and add car? Aromatic polyamide 100
After thoroughly dispersing the mixture, it was cast onto a stainless steel drum and concentrated.

The concentrated film was peeled off from the drum, continuously introduced into a water bath, extracted inorganic salts and removed water, and then stretched at a stretching ratio of 1.2 times until the solid content concentration reached 50%.
Drying and heat fixing were performed at 0° C. to obtain an aromatic polyamide film with a thickness of 4.0 ttrn. On this film support, Ink 1' was hot-melt coated using a Maya parser to obtain a thermal transfer material (I) having an ink layer thickness of 4 to 5 μm.

Comparative Example A thermal transfer material ant was obtained in exactly the same manner as in Example 1, except that the base material in Example 1 was changed to a 4 μPET film.

As described above, thermal transfer recording was performed on the special thermal transfer material (I), ω) under the following conditions.

Head: 24-dot configuration thin film type, dot applied energy/I/A'-〇, 55 w/)Ft and 0.6
5 w/ l'y) Printing speed 20 CPS and 60 CPS (CPS is the number of prints per second) Recording paper Recording results on paper with Beck smoothness of 12 seconds or less (visual inspection of print density and clarity) Table 1
Expressed in

Table 1 Note: ◎ means that it is excellent in practical use, ○ means that it is excellent in practical use, and × means that it is not suitable for practical use.

〔Effect of the invention〕

As described above, in the example of the present invention, heat application energy can be increased even if the base material is thin by using a base material with high heat resistance, and heat transfer efficiency is improved because thermally conductive fine powder is mixed in the base material. Good transfer is obtained with good transfer, and high-speed printing becomes possible.

Claims (1)

[Claims] A thermal transfer material having a thermally transferable ink layer on a support, characterized in that the support is made of an aromatic polyamide film containing thermally conductive fine powder.