JPH0725215B2 - Thermosensitive transfer recording sheet - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heat-sensitive transfer recording sheet, and more specifically, enables printing excellent in heat resistance, abrasion resistance, oil resistance, chemical resistance, print density, and the like. The present invention aims to provide a heat-sensitive transfer recording sheet.

[Conventional Technology and Problems] Recently, the heat-sensitive transfer recording sheet is often used in label printers and bar code printers, but the heat-sensitive transfer layer of the conventional heat-sensitive transfer recording sheet is mainly composed of wax. Because it uses a binder as an ingredient,
There is a problem that the heat resistance, abrasion resistance, oil resistance, chemical resistance, etc. of printing are inferior, and it cannot be used for the above-mentioned applications.

When a resin having good heat resistance is used as the binder, the above-mentioned various printing properties are improved, but the printing thermal sensitivity of the transfer layer is lowered.

[Means for Solving Problems] As a result of earnest research to solve the above problems, the present inventors have found that
By using a specific binder as the binder of the heat-sensitive transfer layer, it is possible to obtain a heat-sensitive transfer recording sheet capable of printing with excellent heat resistance, abrasion resistance, oil resistance, chemical resistance, and printing heat sensitivity. Successful.

The heat-resistant support used in the present invention is, for example, plastic film such as polyester, polycarbonate, triacetyl cellulose, nylon, polyamide, sulfuric acid paper, glassine paper, condenser paper and the like.

The heat-sensitive transfer layer provided on the support is a colorant, a thermoplastic acrylic resin and an epoxy resin, and other additives, lubricants and dispersants, if necessary, in combination with an organic solvent such as toluene or methyl ethyl ketone. Dissolve and add 1 ~ 4μ
It is formed by applying and drying at a ratio of m (dry).

As the colorant to be used, finely powdered inorganic pigments such as carbon black, titanium oxide, iron oxide, aluminum, copper and mica, various organic pigments, fluorescent pigments or dyes are used. If the amount used is too small, the printing density will be low, and if it is too large, the strength of the transfer layer will decrease.

Thermoplastic acrylic resins are various homopolymers and copolymers produced by using acrylic and methacrylic monomers as raw materials, and those having a glass transition point of 50 ° C. or higher and a molecular weight of about 20 to 500 × 10 ³ are suitable. If the amount used is too small, the film strength will be insufficient.

A preferable example of the epoxy resin is a condensation polymer of epichlorohydrin and bisphenol A, which has a melting point of 60 to 15
It is preferably 0 ° C.

The amount of epoxy resin used is in the range of 10-40 parts by weight.
If it is less than part by weight, excellent printing heat sensitivity cannot be expected. or,
If it exceeds 40 parts by weight, heat resistance and wear resistance will be poor.

The additive is at least 1 selected from the group consisting of plasticizers, polyester resins, styrene resins and tackifiers.
Species are preferred, and two or more species can be used together freely.

The composition of the heat-sensitive transfer layer changes to some extent depending on the type of additive.

Examples of the plasticizer as an additive include, for example, adipic acid derivative, azelaic acid derivative, benzoic acid derivative, epoxy derivative, citric acid derivative, glycol derivative, glycerin derivative, fatty acid ester, sulfonic acid derivative, petroleum oil. Derivatives, sebacic acid derivatives, tetrahydrophthalic acid derivatives, trimellitic acid derivatives, biphenyl derivatives, pyromellitic acid derivatives, phthalic acid derivatives, fumaric acid derivatives, paraffin derivatives, polyesters, phosphoric acid derivatives and the like can be used.

The amount of plasticizer used is 1 to 20 parts by weight, preferably 3 to 15
When the amount is less than 1 part by weight, the plasticizing effect can hardly be expected and the printing thermal sensitivity cannot be increased. Further, if it exceeds 20 parts by weight, the thermal sensitivity of printing can be expected to be improved, but problems arise in heat resistance, abrasion resistance, oil resistance and the like.

The polyester resin as an additive has a glass transition point of 30.
A saturated thermoplastic resin having a temperature of ℃ or more and compatible with the thermoplastic acrylic resin is preferable.

The amount of the polyester resin used is in the range of 1 to 30 parts by weight, and if it is less than 1 part by weight, the effect of improving the adhesion of the transfer layer to the support and the printability cannot be expected. On the other hand, if it exceeds 30 parts by weight, the releasability of the transfer layer from the support becomes poor and the heat resistance of printing becomes poor.

Styrene resin as an additive is polystyrene compatible with thermoplastic acrylic resin, styrene copolymer, poly α-methylstyrene, α-methylstyrene copolymer, etc., having a softening point of 60 ° C. or higher. Is desirable.

The amount of styrene resin used is in the range of 10 to 40 parts by weight,
If the amount is less than 10 parts by weight, improvement in printing thermal sensitivity cannot be expected.
If it exceeds 40 parts by weight, heat resistance and wear resistance will be poor.

Examples of the tackifier as an additive include rosin, rosin derivative, terpene resin, natural type such as terpene derivative, petroleum resin, styrene resin, coumarone-indene resin, phenol resin, polybutene, polyisobutylene, etc. A rosin derivative, a terpene resin, a terpene derivative, a petroleum resin, a styrene resin and the like which are compatible with the plastic acrylic resin are preferable.

The amount of tackifier used is in the range of 10 to 40 parts by weight, and if the amount is less than 10 parts by weight, improvement in printing thermal sensitivity cannot be expected. Also 40
If it exceeds the weight part, heat resistance and wear resistance will be poor.

It is preferable to add a lubricant to the above transfer layer up to 20% by weight of the transfer layer. As a lubricant, polyethylene wax, polyethylene oxide, polytetrafluoroethylene, synthetic paraffin, chlorinated hydrocarbon, micro wax, natural paraffin, hydrocarbon paraffin such as fluid paraffin, fatty acid,
There are fatty acid amide type, fatty acid ester type, alcohol type, metal soap type, etc., but considering heat resistance and abrasion resistance, polyethylene wax, oxidized polyethylene wax, polytetrafluoroethylene, fatty acid amide type, metal soap type, etc. Is preferred.

It is not necessary to use these lubricants, but by using them, more excellent abrasion resistance printing can be obtained.

Example 1 Carbon black (MA-10 manufactured by Mitsubishi Kasei) as a coloring agent
0) 15 parts by weight, thermoplastic acrylic resin (manufactured by Mitsubishi Rayon, Dianal BR82) 70 parts by weight, epoxy resin (made by Yuka Shell Epoxy, Epicoat 1001) 20 parts by weight, polyester resin (made by Toyobo, Byron 200) 5 parts by weight Parts and 5 parts by weight of a plasticizer (di-2-ethylhexyl adipate) are dissolved and dispersed in a 1: 1 mixed solvent of toluene and methyl ethyl ketone. This mixed solution was applied to a 5.7 μm polyester film and dried to form a heat-sensitive transfer layer having a coating amount of 1.8 g / m ² .

The resulting heat-sensitive transfer recording sheet was printed on a label for art paper with Bonn label printer BLS-303 at a printing energy of 0.9 mJ / dot, resulting in heat resistance, abrasion resistance, oil resistance and resistance. A high-density image excellent in various physical properties such as chemical properties was obtained.

Example 2 15 parts by weight of a yellow pigment (manufactured by Dainichiseika, Seika First Yellow 2200) as a colorant, 40 parts by weight of a thermoplastic acrylic resin (manufactured by Mitsubishi Rayon, DIANAL BR82), an epoxy resin (manufactured by Yuka Shell Epoxy, Epicoat) 1004) 20 parts by weight, polyester resin (manufactured by Toyobo, Byron 200) 5 parts by weight, plasticizer (di-2-ethylhexyl sebacate) 10
10 parts by weight of a lubricant (MPP-635VP, manufactured by Micro Powder) are dissolved and dispersed in a 1: 1 mixed solvent of toluene and methyl ethyl ketone. This mixed solution was applied to a polyester film of 4.0 μm and dried to form a heat-sensitive transfer layer having a coating amount of 2.3 g / m ² .

Printing was performed in the same manner as in Example 1 using the obtained heat-sensitive transfer recording sheet, and similarly excellent results were obtained.

[Advantages of the Invention] As described above, the present invention provides a heat-sensitive transfer recording sheet capable of printing with excellent heat resistance, abrasion resistance, oil resistance, chemical resistance, printing heat sensitivity and the like.

Claims (1)

[Claims] 1. A heat-sensitive transfer recording sheet characterized by comprising a heat-sensitive transfer layer comprising a colorant, a thermoplastic acrylic resin and an epoxy resin as main components on the surface of a heat-resistant support.