JPS6239290A - Thermal transfer material - Google Patents

Abstract

PURPOSE:To ensure excellent sticking resistance, lubricating properties at the time of running and durability and enable printing with favorable quality to be performed while maintaining efficiency of heat transfer to an ink layer, by providing a layer comprising a heat-resistant lubricant on a side of a base opposite to the side of a thermally transferable ink layer. CONSTITUTION:The thermal transfer material 1 comprises the thermally transferable ink layer 3 on one side of the base consisting of a plastic film, and a lubricative layer 4 having a nonuniform thickness and comprising a heat- resistant lubricant on the back side of the base 2. The lubricative layer 4 can be obtained by nonuniformly applying a material comprising the lubricant and other ingredients, ordinarily in the form of a solution, to the base by gravure coating, screen coating, spray coating or the like, followed by eliminating the solvent. It is preferable that each of the islands of the layer 4 has a diameter of not more than 1mm and a thickness of 0.1-1.5mum, and the total area of the islands is 10-70% based on the surface area of the base, more preferably, 35-60%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a thermal transfer material used in 1.4 thermal transfer recording.

[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 light, continuous, and has no sound.
Operability and maintainability (excellent).Among the four recording papers used in the thermal recording method that have been widely used recently, ordinary thermal recording paper contains a color former and a color developer. Because it is a colored processed paper, it is expensive, records can still be tampered with, the recording paper easily develops color due to heat or organic solvents, and recorded images fade in a relatively short period of time. It has the disadvantage of poor storage stability.

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.

This heat-sensitive transfer recording method generally uses a heat-sensitive transfer material formed by melt-coating a heat-transferable ink layer consisting of island-colored burrs dispersed in a heat-melting binder on a sheet-like support. 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 by a thermal head to transfer the melted ink layer to the recording medium. , a transfer ink image is formed on the recording medium according to the heat supply shape (base turn). According to this method, it is possible to maintain the above-mentioned advantages of the thermal recording method, use plain paper as a recording medium, and eliminate the above-described disadvantages associated with the use of thermal recording paper.

The heat-sensitive transfer material used in this heat-sensitive transfer recording method is generally rolled into a roll and sold commercially. A thin plastic film (base film) is often used so that a large amount can be removed. However, in thermal transfer materials that use such a base film as a support, if the surface temperature of the thermal head exceeds the softening temperature of the base film, the melted or softened base film will adhere to the thermal head, and in severe cases, This causes problems such as the feeding of the thermal transfer material being hindered (the so-called stick phenomenon) and the thermal conductivity from the thermal head to the base film being significantly reduced. Therefore, the surface temperature of the thermal head must be kept below the softening temperature of the base film.

On the other hand, there is a strong demand for faster recording, but in order to achieve this it is necessary to shorten the supply time of thermal energy, which means increasing the temperature of the thermal head or lowering the melting temperature of the thermal transfer ink layer. is required. however,
When the melting temperature of the ink layer is lowered, the ink layer becomes sticky even at relatively low temperatures, resulting in disadvantages such as: 1. Deterioration of the storage stability of the thermal transfer material and staining of non-printing areas of the recording medium.

Conventionally, as a countermeasure to these problems, in order to enable the use of a thermal head at a temperature as high as possible, the surface of the base film of the thermal transfer material that is in contact with the thermal head (i.e., the surface opposite to the surface on which the thermal transfer ink layer is formed) has been used. Is there a vapor deposition film of metal such as aluminum or silicone resin on the side surface)? It has been proposed to provide a layer of heat-resistant resin such as xylene resin, melamine resin, phenol resin, or polyimide resin, or to provide a heat-resistant film filled with an inorganic pigment with high viscosity in the heat-resistant resin. There is. On the other hand, there are also cases in which a highly slippery heat-resistant silicone oil or the like is applied to the surface of the thermal head to prevent melted base films or the like from adhering to the head.

However, even in the former method of providing a heat-resistant film, the surface of the thermal head and the heat-resistant film are in direct contact, so the film is usually exposed to temperatures around 250 to 300°C, and furthermore, under normal printing conditions, it is exposed to heat from the thermal head as well as the heat-resistant film. Since pressure is applied between the thermal head and the recording medium, it is necessary to increase the film thickness in order to form a film that is completely durable against the effects of heat and pressure.

In that case, it is not preferable because it causes a decrease in thermal efficiency.

On the other hand, if the film thickness is made thinner, the durability becomes insufficient, and the broken heat-resistant film mixes with the melted base film and adheres to the surface of the heat head, causing problems such as sticking.

Furthermore, in the method of applying a highly slippery heat-resistant oil or the like to the surface of the thermal head, it is necessary to reapply the oil during recording, which is inconvenient in practice.

[Problems to be solved by the invention]

The present invention solves the conventional problems and 1. The objective was to provide a thermal transfer material that has excellent statesking resistance, lubricity during running, and durability, and that can produce good quality prints without reducing the efficiency of heat conduction to the ink layer. It is something.

[Means and effects for solving the problems] That is, the thermal transfer material provided by the present invention has a thermal transferable ink layer on a support, in which the thermal transferable ink layer of the support is It is characterized in that a layer containing a heat-resistant lubricant is provided on the opposite surface.

In this way, the present invention, in principle, only needs to form a monomolecular film of lubricant on the surface of the thermal head, and even if the lubricant layer is provided unevenly, sufficient stability resistance and stability during running can be achieved. This is based on the knowledge that it provides lubricity and durability.

Furthermore, as conceptually shown in Figure 1, in the case of a uniform lubricant layer (fractured), as the amount (thickness) of the lubricant increases, the lubricity and statesking resistance change in a nearly linear manner. In contrast, in the case of a non-uniform lubricant layer (solid line), it was confirmed that the effect rapidly improved in the region of a small amount of coating.

On the other hand, the thermal efficiency of the ink layer is in the case of a homogeneous system (dotted chain line).
, it attenuates in a shape close to a straight line, but in the case of a non-uniform system (double-dashed line), it does not change linearly as the amount of coating increases,
It was confirmed that the attenuation occurs gradually depending on the contact situation between the heat source and the support.

Therefore, by providing a layer of the old lubricant in an island shape (including dot shape, etc.) as a non-uniform system, it is possible to improve the properties as described above, as well as improve the contradictory property of thermal efficiency to the ink layer. 〇Based on this knowledge, the present invention has been designed to improve the statesking resistance and maintenance by applying a small amount of lubricant as a non-uniform layer such as an island. The contradictory properties of lubricity, durability, and heat transfer to the ink layer can be achieved simultaneously in a well-balanced manner.

[Detailed description and examples of the invention]

Hereinafter, the present invention will be described in further detail with reference to the drawings as necessary. In the following description, "quantity ratio" is used as "
Unless otherwise specified, "%" and "parts" are based on weight.

FIG. 2 is a schematic cross-sectional view in the thickness direction of one configuration example of the most basic thermal transfer material of the present invention, and FIG. 3 is a view taken in the direction of arrow A in FIG.

The thermal transfer material 1 shown in the second image has a thermally transferable 172 layer 3 formed on one side of a support 2 made of plastic or plastic film, and a lubricant containing a low-temperature lubricant having an uneven thickness on the back side. A sexual layer 4 is formed.

Examples of the plastic film constituting the support 2 include polyethylene terephthalate, polycarnate,
Plastic films with relatively good heat resistance such as triacetylcellulose, nylon, and polyimide, cellophane, etc. are suitable for use.

Among these, polyethylene terephthalate (hereinafter referred to as PET) is most preferably used because it is easy to process into a thin film and has an excellent balance of strength, heat resistance, and cost. The thickness of the support is preferably thin in consideration of heat transfer from the thermal head to the thermal transfer ink layer, but from the viewpoint of support strength, it is preferably 1 to 15 μm, particularly preferably 2 to 10 μm. It will be done.

The thermal transfer ink layer 3 is basically formed by dispersing a colorant in a heat-melting binder.

As the heat-melting binder, carnauba wax,
Waxes such as Seraphin wax, Sasol wax, Microcrystalline wax, Castor wax;
Higher fatty acids or their metal salts such as stearic acid, certimic acid, lauric acid, aluminum stearate, lead stearate, barium stearate, zinc stearate, zinc rumitate, methylhydroxystearate, glycerol monohydroxystearate, Derivatives of esters, etc.; polyethylene, polypropylene, polyimbutylene, polyethylene wax, polyethylene oxide, polytetrafluoroethylene, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, etc. Thermoplastic resins made of olefins alone or copolymers or derivatives thereof,
etc. are used. These heat-fusible binders may be used alone or after heating two or more f1.

In addition, the coloring agents include Cargon Pla, Li, Nigrosine Dye, Lamp Black, Sudan Black S to 1, Alkali Blue, First Niro G, Bennoson Niro, Pigment Niro, Indo First Orange, Irgazin Red). ? 1. J Nitroaniline Red, Toluidino Red, J)-Min FB, /+-Manent Bordeaux FRR, Pigment Orange R1 Lysol Red 2G, Lake Red C10-Damine FB, Rhodamine B Lake, Methyl Violet B Lake, Phthalo/Annine Blue, Pigment Blue, Prilliant Green A1 Phthalocyanine Green, Oil Yellow GG, fN First Niro 1000, Kaya.

To Y963, Kayaset'YG, Sumiplast Elo-GG, Deden Fast Orenno RR, Oil Scarlet, Sumiplast Orange G1 Orazole Brown B1 Devon First Scarlet CG, Eizen Spiro/Red, BEI (, Oil Pink OP1 Victoria Blue F4R, First Dan Blue 5007,
All known dyes and dyes such as Sudan Blue and Oil Peacock Blue can be used.

The above-mentioned hot-melt binder and coloring agent are mixed in advance and applied to the support base film 2 by hot-melt coating, or by coating a solvent solution or dispersion of these.
A thermally transferable ink layer 3 of 0.5 to 30 μm, preferably 1 to 20 μm, is provided on top.

The lubricating layer 4 according to the present invention contains a heat-resistant lubricant as an essential component, and may also contain a binder, a surfactant, etc. in consideration of retention on a support.

Heat-resistant lubricants include dimethyl silicone, methylphenyl silicone nato silicone oil, barfluoroalkylsulfonic acid potassium salt, /#-fluoroalkylcargonic acid potassium salt, heptadonated alkyl ester, perfluoroalkyl acrylate, and fluorinated Fluorine compounds such as hydrocarbons, and silicone modified resins such as epoxy resins, polyester resins, acrylic resins, and urethane resins are often used.

The lubricity layer 4 is obtained by applying a solution of the above-described heat-resistant lubricant or other compound non-uniformly onto the support by gravure coating, screen coating, spray coating, etc., and removing the solvent. . The size of the island is 1 mm or less in diameter, 0.1 to 1.5 μm in thickness, and the ratio of the island area to the surface area of the support is 10 to 70%, and even 3 mm.
It is preferable to reduce the amount by 5 to 60%. With such specifications, the coating amount of the lubricating layer is usually 0.01 to 2 y/d dry weight.
m, preferably 0.02 to 197 m.

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

Example Carden black 10 parts Imontan wax 20 parts Low molecular weight polyethylene oxide 10 parts Paraffin wax 6ON The ingredients of the above recipe were heated to 100°C and heated in a sand mill for 3 minutes.
By mixing for 0 minutes) an ink is obtained, which is 4 μm thick.
A heat-sensitive transfer material having a 4 μm ink layer was obtained by hot-melt coating on a PPT film. On the opposite side of the ink layer of this thermal transfer material, apply the following compounded liquid at a dry weight of 0.21/m2.
A back-treated heat-sensitive transfer material of the present invention was obtained by spray coating and heating and drying.

When this was printed using a Canon (Aji) electronic typewriter, Typestar Φ5, the recording was made with smooth running without sticking.

Comparative Example 1 A back-treated heat-sensitive transfer material was obtained in the same manner as in Example, except that the back-treated layer was blade coated to obtain a uniform film (dry coating amount: 0.2 F/m). Printing was performed in the same manner, but sticking occurred and the printing did not run smoothly.

Comparative Example 2 When printing was carried out in the same manner using the heat-sensitive transfer material that was not subjected to the back surface treatment in the example, the material stuck so severely that it became impossible to run it.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram for explaining the relationship between the coating amount of the lubricating layer on the surface of the support and the properties. FIG. 2 is a schematic cross-sectional view in the thickness direction of one example of the structure of the most basic thermal transfer material of the present invention), and FIG. 3 is a view taken along the arrow in FIG. DESCRIPTION OF SYMBOLS 1...Thermal transfer material, 2...Support, 3...Thermal transferable ink layer, 4...Lubricating layer. Agent Patent Attorney Jo Taira Yamashita Figure 2A Figure 3

Claims (4)

[Claims] (1) A heat-sensitive transfer material having a heat-transferable ink layer on a support, characterized in that a layer containing a heat-resistant lubricant is provided on the surface of the support opposite to the heat-transferable ink layer. Thermal transfer material. (2) The thermal transfer material according to claim (1), wherein the island layer is provided over 10 to 70% of the surface area of the support. (3) The thermal transfer material according to claim (2), wherein the island layer is provided over 35 to 60% of the surface area of the support. (4) The thermal transfer material according to any one of claims (1) to (3), wherein the island layer has a thickness of 0.1 to 1.5 μm.