JPS6374687A - Thermal transfer material - Google Patents

Abstract

PURPOSE:To prevent sticking phenomenon and the release of a reverse layer to obtain good running properties, by a method wherein a thermal transferring ink layer is provided on a substrate and a layer mainly composed of polyurethane fluorid is formed on the opposite surface to a surface facing the thermal transferring ink layer. CONSTITUTION:On the opposite (reverse) surface to a thermal transferring ink layer forming surface of a substrate, a layer mainly composed of polyurethane fluoride is provided. The polyurethane fluoride has urethane bond, i.e.- NHCOO-in the main chain, and fluorinated hydrocarbon radical wherein fluorine atom is substituted for at least one hydrogen atom, and is allowed to be relatively low in molecular weight if it has coat forming properties. On the other hand, the maximum molecular weight is preferably in such extent that the compound can dissolve in a solvent generally used for solvent coating. A thermal transfer material may be obtained in such a manner as that ; the polyurethane fluoride is coated on a surface of the substrate by solvent coating etc. and dried and, thereafter, the thermal transferring ink layer is formed on the opposite surface thereof by hot melt coating, solvent coating, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal transfer material used in a thermal transfer recording method.

11. In addition to the general characteristics of thermal recording methods, such as the device used is lightweight, compact, noiseless, and has excellent operability and maintainability, the thermal transfer recording method does not require color-forming processed paper; Furthermore, it has the feature of excellent durability of recorded images, and has been widely used recently.

This thermal transfer recording method generally uses a thermal transfer material made by coating a sheet-like support with a thermal transfer ink made of a heat-melting binder and a colorant dispersed therein. The thermal transfer ink layer is superimposed on the recording material so as to be in contact with the recording material, and heat is supplied from the support side of the thermal transfer material by a thermal head to transfer the melted ink layer onto the recording material. A transfer recording image is formed on the material according to the shape of heat supply.

When heat is supplied from the support side of the thermal transfer material in this way,
Since the support reaches a high temperature, the support melts, adheres to the thermal head, and solidifies, resulting in a stick phenomenon in which the thermal transfer material cannot run.

In order to prevent this kind of stick phenomenon, a method of providing a heat-resistant protective film on the support has been studied. ,Epoxy resin,
A heat-sensitive transfer material provided with a heat-resistant protective film selected from the group consisting of melamine resin, phenol resin, fluororesin (fluorinated polyolefin resin), polyimide resin, and cellulose has been proposed.

However, increasing the heat resistance and lubricity of such a conventional heat-resistant protective film reduces its adhesion to the support, making it easier for the protective film to peel off from the support, which can adversely affect the running of the thermal transfer material. There was a tendency to lower the sex.

The main object of the present invention is to provide a thermal transfer material with good runnability that eliminates the above-mentioned drawbacks.

The thermal transfer material of the present invention was developed to achieve the above object, and comprises a layer of thermally transferable ink on a support, and a layer of thermally transferable ink on the surface of the support opposite to the thermally transferable ink layer. It is characterized in that a layer containing fluorinated polyurethane as a main component is provided on the opposite side.

The present invention will be explained in more detail below. In the following description, "1 part" and "%" expressing quantitative ratios are based on weight unless otherwise specified.

The heat-sensitive transfer material of the present invention includes a layer containing fluorinated polyurethane as a main component on the surface (back surface) opposite to the surface on which the heat-transferable ink layer is formed of the support.

In the present invention, "fluorinated polyurethane" refers to a resin having a urethane bond -NHCOO- in the main chain and a fluorinated hydrocarbon group in which at least some hydrogen atoms are replaced with fluorine atoms. .

In the present invention, a fluorinated polyurethane having at least one of the following partial structures (I) or (II) is preferably used.

RF-00CNHR'NHCOO-(I) In the above formula, R
2 represents a fluorinated hydrocarbon group having 1 to 30 carbon atoms (preferably 5 to 20) in which some or all of the hydrogen atoms are substituted with two or elementary atoms, and is a 05 to C25 perfluoroalkyl group. More preferably.

Mata, R is -H1CH*, CH2X, -CHX2
, CXg (X represents F, C1, Brc7).

In the above formula, R' has 2 to 20 carbon atoms (preferably 2
~8) represents a divalent hydrocarbon group, n represents an integer of 0 to 20 (preferably 0 to 10).

The molecular weight of the fluorinated polyurethane used in the present invention is relatively low as long as it has film-forming properties (see Examples below).
On the other hand, the upper limit of this molecular weight is not particularly limited, but (from the viewpoint of facilitating solvent coating) solvents commonly used for solvent coating (
For example, organic solvents such as toluene, ethyl acetate, IPA, etc.)
The molecular weight is preferably such that it can be dissolved in 100 parts of ethyl acetate, and more preferably the molecular weight is such that about 10 to 30 parts can be dissolved in 100 parts of ethyl acetate.

The above-mentioned fluorinated polyurethane is obtained according to a conventional method, for example, by reacting a corresponding diisocyanate with a glycol or an alcohol having a fluorinated hydrocarbon group.

Further, the above-mentioned partial structure of the fluorinated polyurethane used in the present invention has been confirmed by instrumental analysis means such as nuclear magnetic resonance absorption (NMR).

In the present invention, two or more of the above-mentioned fluorinated polyurethanes may be used in combination, if necessary.

In addition, in order to improve coating properties and lubricity, it is preferable to add surfactants, lubricants such as silica, talc, Teflon paratar, and fillers.These surfactants, lubricants,
The amount of additives such as fillers added is preferably 30 parts or less (more preferably 10 parts or less) per 100 parts of fluorinated polyurethane.

The thickness of the back layer containing fluorinated polyurethane as a main component is preferably about 0.2 to 5 mm, more preferably about 0.5 to 2 gts.

The thickness of this fluorinated polyurethane layer is 0, 2 JLa1
If it is less than that, it will be difficult to suppress the stick phenomenon.

When the thickness of one side exceeds 5 pL11, the thermal efficiency of patterned heat application decreases.

On the other hand, as the support, conventionally known films and papers can be used as they are; for example, films made of relatively heat-resistant plastics such as polyester, polycarbonate, triacetylcellulose, polyamide, and polyimide are preferably used. .

The thickness of this support is preferably about 3 to 30 pm.

In the thermal transfer material of the present invention, the structure of the thermal transferable ink layer provided on the support is not particularly limited. It may also be composed of an ink layer.

The ink constituting such a thermally transferable ink layer is made by dispersing a colorant in a heat-melting binder (this does not mean that the colorant is in a dissolved state).

As the heat-melting binder, binders conventionally used in heat transfer inks can be used as they are.

Examples of such heat-melting binders include natural waxes such as spermaceti wax, beeswax, lanolin, carnauba wax, candelilla wax, montan wax, and ceresin wax; petroleum waxes such as paraffin wax and microcrystalline wax; oxidized waxes; Synthetic waxes such as ester wax, low molecular weight polyethylene, Fischer-Tropsch wax; lauric acid.

Higher fatty acids such as myristic acid, palmitic acid, stearic acid, and behenic acid; higher alcohols such as stearyl alcohol and behenyl alcohol; esters such as sucrose fatty acid ester and sorbitan fatty acid ester; amides such as oleylamide; or polyolefins resins, polyamide resins, polyester resins, epoxy resins, polyurethane resins, polyacrylic resins, polyvinyl chloride resins, cellulose resins, polyvinyl alcohol resins, petroleum resins, phenolic resins, polystyrene resins , resins such as vinyl acetate resins; elastomers such as natural rubber, styrene-butadiene rubber, in-prene rubber, and chloroprene rubber; and the like.

The above-mentioned heat-melting binders may be used in combination of two or more types as necessary, and the binder may be mixed with so-called liquid rubber such as polyisobutylene or polybutene, or with a plasticizer, an oil agent, a surfactant, etc. Adding additives to adjust the supercooling property, melt viscosity, adhesive strength, degree of wood-philicity-hydrophobicity, etc. is also known as circling.

As the coloring agent constituting the thermal transfer ink together with the above-mentioned heat-melting binder, all known dyes and pigments used in the printing and recording fields, such as carbon black, can be used.

To obtain the thermal transfer material of the present invention, for example, a solvent coat (forming a thin fluorinated polyurethane layer) of fluorinated polyurethane (to which a surfactant, filler, lubricant, etc. are added as necessary) is applied to one surface of the support. After forming a fluorinated polyurethane layer by coating by a conventional method such as (preferable from the viewpoint of fluorinated polyurethane layer formation) and drying as necessary, coat the surface of the support opposite to the surface on which the fluorinated polyurethane layer is formed by applying a coating method such as HO, TOMELTO COAT, Preferably, the thickness is 1 to 20 p by a conventional method such as solvent coating.
, m of thermal transferable ink layers may be formed.

The thermal transfer material of the present invention can be used in a thermal transfer recording method according to a conventional method without any particular restriction.

As described above, according to the present invention, there is provided a heat-sensitive transfer material in which a fluorinated polyurethane layer is provided on the back surface of a support.

When the thermal transfer material of the present invention is used, the sticking phenomenon and the peeling of the back layer can be effectively suppressed, and good running properties can be obtained when the thermal transfer material is used.

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

Support 1 A 10% ethyl acetate solution of fluorinated polyurethane having the following structure was applied to one side ('! A side) of a polyethylene terephthalate film with a thickness of 6 uLm as a support to a dry thickness of lp.
After forming a fluorinated polyurethane layer by coating it in an amount of □, carbon is added to the surface of the support (the surface opposite to the surface on which the fluorinated polyurethane layer is formed) in a paint made of wax and ethylene-vinyl acetate. A heat transferable ink having black uniformly dispersed therein was applied using a hot melt coater to form a heat transferable ink layer having a thickness of 5 mm.

RC2H400CNH-R'NHCOORF' (In the above formula, R, R,' represent a C8 to C4 fluorinated hydrocarbon group, and R' represents a C6 divalent hydrocarbon group.) The book obtained as above Invented thermal transfer material.

It was attached to a commercially available thermal transfer recording device (Type Star 5, manufactured by Canon), and the energy applied to the thermal transfer material was 35 mJ.
/mm2, transfer speed of thermal transfer material 46 IIm/sea
When thermal printing was carried out, no sticking phenomenon occurred, there was little damage to the support, and good running properties of the thermal transfer material were obtained.

L-Ko 1 A heat-sensitive transfer material was obtained in the same manner as in the example except that the fluorinated polyurethane layer was not formed on the back surface of the support, and when thermal printing was performed using this heat-sensitive transfer material in the same manner as in the example, the support was Her body was severely damaged and she was prone to stick symptoms.

Claims (1)

[Claims] A layer of thermally transferable ink is provided on a support, and a layer containing fluorinated polyurethane as a main component is provided on the surface of the support opposite to the surface facing the thermally transferable ink layer. Thermal transfer material.