JPS60212389A - Thermal transfer material - Google Patents

Abstract

PURPOSE:To provide a thermal transfer material capable of providing recorded images having excellent thermal and mechanical durability, wherein a thermally transferrable ink layer comprising a heat-fusible binder, a coloring agent and a heat-crosslinkable resin compound is provided on a base. CONSTITUTION:An ink obtained by mixing a heat-fusible binder (e.g., carnauba wax), a heat-crosslinkable resin compound (e.g., a combination of an aminoplast resin and a potential acid catalyst) and a coloring agent (e.g., carbon black) by an appropriate method is applied to a base (e.g., a plastic film), and is dried to provide a heat-fusible ink layer, thereby obtaining the objective thermal transfer material. EFFECT:Excellent in preservability and capable of producing transfer-recorded images havine excellent fretting resistance and high-temperature preservability on a recording medium.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal transfer material that provides recording with excellent durability.

11. 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, compact, 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 easily developing color due to heat or organic solvents, and the recorded image fading in a relatively short period of time. Maintaining the advantages of the above-mentioned thermal recording method,
A thermal transfer recording method has recently attracted particular attention as a method to compensate 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 consisting of a colorant dispersed in a heat-meltable binder onto 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 onto the recording medium. , a transfer ink image is formed on a recording medium according to the shape of heat supply. 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.

However, even the thermal transfer recording method having such excellent characteristics is not without drawbacks.

In other words, as mentioned above, the heat-transferable ink layer of conventional heat-sensitive transfer materials has a colorant dispersed in a heat-melt binder, but this heat-melt binder is a reversible heat-transferable ink layer. Since it has melting properties and is relatively brittle, the recorded image after thermal transfer also tends to become brittle, and it may soften or remelt at high temperatures. Therefore, if the surface of the recording section is rubbed, it is likely to become smudged or peeled off, and if the recording medium is stored at high temperatures, the recorded image may smear, and if stacked one on top of another, it may cause set-off. Phenomena such as these are occurring. Therefore, in reality, thermal transfer recording methods are not used for applications such as certificates, display boards, labels, commuter passes, etc., which require durability of recorded images.

The main object of the present invention is to provide a thermal transfer material that eliminates the drawbacks of the conventional thermal transfer materials mentioned above and provides a recorded image with excellent thermal and mechanical durability.

Lord”Lnu1! According to the research conducted by the present inventors, it has been found that it is extremely effective to include a thermally crosslinkable resin compound in the thermally transferable ink layer in order to achieve the above-mentioned object. That is, using the heat-sensitive transfer material obtained in this way,
When thermal transfer recording is performed, crosslinking of the compound progresses due to the heat and melt mixing effect during recording, or due to subsequent heating, heat, etc., and the resulting three-dimensional structure reduces the durability of the recording ink image at high temperatures. It has been found that there is a significant improvement in both scratch resistance and abrasion resistance.

The thermal transfer material of the present invention is based on the above-mentioned findings, and more specifically, the thermal transfer ink layer is formed on a support, and the thermal transfer ink layer includes a heat-melting binder, a heat-melting binder,
It is characterized by containing a heat-crosslinkable resin compound in addition to a coloring agent.

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

The basic layer structure of the thermal transfer material of the present invention is not particularly different from that of conventional thermal transfer materials, and consists of a thermal transferable ink layer formed on a support.

As the support, conventionally known films and papers can be used as they are, such as relatively heat-resistant plastic films such as polyester, polycarbonate, triacetyl cellulose, nylon, and polyimide;
Top/X-type paper 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 during thermal transfer, but for example, 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. 'Also, 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. The heat resistance of the support can be improved by
Alternatively, support materials that could not be used conventionally can also be used.

The transferable ink layer contains a heat-melting binder, a colorant, and a heat-crosslinkable resin compound as main components.

Heat-melting binders include waxes such as carnauba wax, paraffin wax, Sasol wax, microcrystalline wax, and castor wax; stearic acid, palmitic acid, lauric acid, aluminum stearate, lead stearate, barium stearate, Higher fatty acids such as zinc stearate, zinc palmitate, methyl hydroxystearate, glycerol monohydroxystearate or their metal salts, derivatives such as esters; polyethylene, polypropylene, polyisobutylene, polytetrafluoroethylene, engineered tyrene-acrylic acid Thermoplastic resins made of olefins alone or copolymers, such as ester copolymers, ethylene-vinyl acetate copolymers, or derivatives thereof, are used. As a heat-melting binder, the melting point or softening point is usually 60 to 1 by mixing one or more of the above components.
The temperature range is 20°C.

In addition, as for the heat-crosslinkable resin compound used in combination with the heat-melt binder, the reaction does not proceed below the melting point of the heat-melt binder, and the reaction starts during heat transfer, or at the latest, the crosslinking reaction starts after transfer. , after that, the reaction proceeds even at room temperature and becomes three-dimensional. In addition, in a combination of compounds that are inherently reactive even at room temperature and become three-dimensional, one component can be microencapsulated to create a stable mixed system, and the walls of the microcapsules can be destroyed by heating to mix. If the crosslinking reaction proceeds before thermal transfer, which may be a reaction/three-dimensional system, the softening temperature or melt viscosity of the thermal transferable ink layer will increase significantly, resulting in a decrease in thermal transferability.

The heat-crosslinkable resin compound may be a single substance or a combination of two or more substances, and specifically, for example, the following compounds are used. That is, a combination of an aminoplast resin derived from urea, melamine, etc. and a latent acid catalyst,
A combination of a polyisocyanate blocked with a blocking agent such as acetylacetonate or phenol and a polyvalent active hydrogen-containing compound such as a polyester polyol, a combination of a microencapsulated amine curing agent and an epoxy resin, and a latent curing acceleration. agents (such as cobalt naphthenate powder coated with acrylic resin); combinations of peroxides (such as ketone peroxides) and unsaturated polyesters.

The amount of these heat-crosslinkable resin compounds to be added may be such that the abrasion resistance and high-temperature storage stability of the recording medium after heat transfer, which are the objectives of the present invention, can be achieved, and the heat-melt binder is usually 100% added.
A range of 2 to 50 parts per part is preferably used. If the amount is less than 2 parts, the desired effect will not be sufficiently obtained, and if it is less than 50 parts, the melt viscosity of the thermal transfer ink layer will increase, resulting in poor thermal transfer properties, or the thermal transfer ink layer will become sticky and non-stick. This is inconvenient as it may stain the printed area.

Coloring agents include carbon black, nigrosine dye, lamp black, Sudan black SM, alkali blue, First Yellow G1 benzidine yellow, pigment yellow, India first orange, irgazine red, varanitroaniline Φ red, toluidine yellow.
Red, Carmine FB, Permanent Bordeaux FRR
, Pigment Orange R1 Lysol Red 20, Lake Red C, Rhodamine FB, Rhodamine B Lake, Methyl-Violet B Lake, Phthalocyanine Blue, Pigment Blue, Prilliant Green B, Phthalocyanine Green, Oil Yellow GG, Zaponya Fast Yellow CGG, Kayaset Y963, Kayaset YG, Sumiplast Yellow G, Zapon First Orange RR, Oilbetsu Scarlet, Sumiplast Orange G, Orazole Brown B, Pomelo First Scarlet CG, Eye Ink Piron Red, BE
All of the various dyes and pigments used in the fields of printing and recording can be used, such as H, Oil Pink OP, Victoria Blue F4R, First Gen Blue 5007, Sudan Blue, and Oil Peacock Blue. These colorants can usually be used in a ratio of 3 to 300 parts, for example, based on 100 parts of the total amount of the heat-melting binder and heat-crosslinkable resin compound.

The heat-sensitive transfer material of the present invention can be prepared by dispersing and mixing the heat-melting binder and colorant in advance using an attritor, sand mill, etc., and then mixing the heat-crosslinkable resin compound, or by mixing the colorant, heat-meltable binder, heat-crosslinking, etc. The ink obtained by mixing the resin compound by an appropriate method such as dispersion mixing at the same time is coated on a support, and thermal transfer is performed to a dry thickness of 0.5 to 30 IL, preferably 1 to 20 JL. This can be obtained by forming a transparent ink layer.

The thermal transfer recording method using the thermal transfer material of the present invention thus obtained is not particularly different from a conventional method. After the media are laminated and heat is supplied in a pattern according to the desired recording pattern, preferably from the support side of the thermal transfer material using a thermal head or laser beam, the thermal transfer material and the recording medium may be dispersed. .

As described above, according to the present invention, by forming a heat-transferable ink layer containing a heat-crosslinkable resin compound in combination with a heat-melting binder, it has excellent storage stability, and also provides scratch resistance on the recording medium. Provided is a heat-sensitive transfer material that provides a transferred recorded image with excellent durability and high-temperature storage stability.

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

Support 1 Carbon black...IIΦ, 10 parts polyethylene wax (softening point approx. 95℃) Fist...20 parts paraffin wax (softening point approx. 70℃), No. 11...60 parts Karna Ubawax: Sha, Yu, 10 parts Dispersed by heating with the above attritor on each side, and the obtained carbon black dispersion is about 10 parts.

While heating to 0C, 400 parts of a toluene/xylene mixed solvent (mixing ratio 50150) was added thereto, stirred vigorously, and then cooled to room temperature to obtain a fine dispersion of wax.

Next, 10 parts of hexamethoxymethylolmelamine and 1 part of ammonium p-toluenesulfonate were added and mixed to 100 parts of the above dispersion to obtain a coating liquid for forming an ink layer.

The above coating solution was applied onto a polyethylene terephthalate film with a thickness of 6IL using a knife coater, and
It was dried at C to form an ink layer with a thickness of 5 ml to obtain a thermal transfer material.

This transfer material is transferred to high-quality paper (120g/nIt) using a thermal head.
), a printing test was conducted and clear printing was obtained. When the printed portion of the obtained transfer record was rubbed, there were no problems such as staining or peeling. In addition, the above transfer recording sheets were stacked at 40°C and 0.5 kg/n? Although it was left for 1 hour under a load of 1, no transfer to the upper layer of the printed area or bleeding was observed.

A thermal transfer material was obtained in the same manner as in the example except that hexamethoxymethylolmelamine and ammonium P-toluenesulfonate were not added to the ink layer forming coating solution of the 10-mouth example, and this thermal transfer material was used. When we conducted a printing test, clear printing was obtained.

However, when the printed area of the resulting transfer record was rubbed, stains were found in the non-printed area. Further, when the transfer recording sheets were stacked together in the same manner as in the example, transfer to the upper layer of the printed portion and bleeding were observed.

Claims (1)

[Claims] A heat-sensitive transfer material comprising a heat-transferable ink layer formed on a support, the heat-transferable ink layer containing a heat-crosslinkable resin compound in addition to a heat-melting binder and a colorant.