JPH05246159A - Thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To prevent the blocking of a thermal transfer recording medium wherein a solvent dispersion type ink layer is provided on the hot-melt anchor coat layer provided on a base material without increasing the content of the resin in the anchor coat layer. CONSTITUTION:The surface smoothness of a hot melt anchor coat layer is set to 9,000sec or more. By setting the surface smoothness to 10,000-30,000sec, blocking can be effectively prevented even in a resin content of about 2%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer recording medium, and more particularly to a thermal transfer recording medium having an anchor coat layer interposed between a substrate and an ink layer.

[0002]

2. Description of the Related Art A thermal transfer recording medium is generally formed by coating a base material such as a film with a thermal transferable ink layer mainly composed of a heat-fusible binder and a colorant. However, the transferability of the ink layer is greatly affected by the surface smoothness of the transfer paper, and good printing is performed on the transfer paper with high smoothness, but the print quality is remarkably high on the transfer paper with low smoothness. descend.

Therefore, a plurality of heat-fusible ink layers are provided, the layer in contact with the base material has releasability from the base material, and the layer on the surface side apart from the base material mainly has thermal transferability to transfer paper. The thermal transfer recording medium that has been shared by the role of has come to be used.

On the other hand, the hot-melt type ink layer has hitherto been mainly used as a hot-melt type ink layer, but recently, solvent-based ink layers have been increasing for the purpose of low cost.

However, the hot-melt ink layer (hereinafter referred to as an anchor coat layer), which has a role of facilitating the peeling from the above-mentioned substrate, may not be able to fulfill its function unless it is a hot-melt type. That is, in the case of the solvent type, the wax needs to be dispersed, and the degree of the dispersion has a great effect on the printing quality, and it is difficult to obtain high smoothness.

This hot-melt type anchor coat layer has a problem of binding property to the substrate and causes blocking.

Therefore, there is a method of increasing the resin content as the composition of the anchor coat layer, but the binding force between the base material and the anchor coat layer is the binding force between the ink layer on the surface and the transfer paper during printing. Since it is more excellent, the thermal transfer property is deteriorated. Therefore, there is no choice but to limit increasing the resin content.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a hot-melt type anchor coat layer on a substrate, and a solvent dispersion type ink layer on the anchor coat layer. An object of the present invention is to provide a thermal transfer recording medium capable of preventing blocking without increasing the resin content.

[0009]

In order to achieve the above object, in the thermal transfer recording medium of the present invention, the surface smoothness of the hot-melt type anchor coat layer is set to 9,000 seconds or more.

In particular, the surface smoothness of 10,000 seconds or more is 30,0
Blocking prevention can be made more effective by setting the time to 00 seconds or less.

In order to achieve the above-mentioned surface smoothness, it is preferable to heat the anchor coat layer surface with a heater roll or a heater fan.

Examples of the heat-melting material constituting the hot-melt type anchor coat layer of the present invention include spermaceti wax, beeswax, lanolin, carnauba wax, castor wax, candelilla wax, montan wax, paraffin wax and microcrystalline wax. Natural wax, oxide wax, ester wax, synthetic wax such as low molecular weight polyethylene, lauric acid, myristic acid, palmitic acid, stearic acid, flumenic acid,
Higher fatty acids such as behenic acid, stearyl alcohol,
Higher alcohols such as behenyl alcohol, fatty acid esters of sucrose, esters such as fatty acid esters of sorbitan, amides such as stearamide, oleinamide, etc. are used as the main components, and within the range satisfying the above requirements of the present invention, polyamide-based Resin, polyester resin, epoxy resin, polyurethane resin, acrylic resin, vinyl chloride resin, cellulose resin, polyvinyl alcohol resin, petroleum resin, phenol resin,
Styrene resin, natural rubber, styrene butadiene rubber,
Elastomers such as isoprene rubber and chloroprene rubber or oils such as mineral oil and vegetable oil may be appropriately mixed and used.

As the heat-melting material forming the solvent type ink layer, polyamide resin, polyester resin, epoxy resin, polyurethane resin, acrylic resin, vinyl chloride resin, cellulose resin, polyvinyl alcohol resin , Petroleum-based resin, phenol-based resin, styrene-based resin, natural rubber, styrene-butadiene rubber, isoprene rubber, chloroprene rubber, etc. may be used as a main component, and the above waxes may be mixed if necessary.

As the base material, for example, polyester,
A plastic film having relatively good heat resistance such as polycarbonate, nylon, or polyimide can be preferably used.

Further, a heat-resistant protective layer made of silicone resin, polyimide resin, epoxy resin, nitrocellulose or the like may be provided on the surface of the base material which comes into contact with the thermal head.

To obtain the thermal transfer recording medium of the present invention,
First, the anchor coat layer material is melted and stirred, and then coated on a base material such as a polyester film at about 100 ° C. with a hot melt coater to form an anchor coat layer. Then, the surface of the anchor coat layer is brought into contact with the surface of a heated heater roll or is treated with hot air by a heater fan to obtain an anchor coat layer having a surface smoothness of 9,000 seconds or more according to Beck's smoothness.

Next, a colorant, a binder resin, a solvent and the like are used to prepare a solvent-dispersed ink layer coating solution using a dispersing device such as an attritor, and this is used to prepare the surface of the anchor coat layer surface. A thermal transfer recording medium is obtained by applying to

[0018]

EXAMPLES The present invention will be described in more detail with reference to the following examples. The parts shown below are based on weight.

[Composition of anchor coat layer] Paraffin wax (paraffin wax 155 manufactured by Nippon Seiro Co., Ltd.) 76 parts Castor wax (hardened castor oil A manufactured by Ito Oil Co., Ltd.) 11 parts Dispersant (polyhydric alcohol lanolin fatty acid ester Yoshikawa Oil Co., Ltd. LANOXFPG = 103) 11 parts Resin (alicyclic saturated hydrocarbon resin Alcon P-90 manufactured by Arakawa Chemical Industry Co., Ltd.) 2 parts were melt-stirred at 120 ° C. Next, it was coated on a polyester film with a hot melt coater at an anchor coat temperature of about 100 ° C. The coating amount was 2.8 ± 0.3 g / m ² .

Next, the surface of the anchor coat layer was surface-treated by setting the surface temperature of the heater roll to 7 levels as shown in the left column of Table 1.

[0021]

[Table 1]

The following solvent dispersion type ink layer composition liquid was applied to the surface of each anchor coat layer surface-treated as described above to obtain a thermal transfer recording medium. [Composition of ink liquid] Carbon black (Mitsubishi Carbon Black # 44 manufactured by Mitsubishi Kasei Co., Ltd.) 4 parts Ethylene / ethyl acrylate copolymer (DuPont Mitsui Polychemical Co., Ltd.) 8.5 parts Styrene resin (Haimer manufactured by Sanyo Chemical Co., Ltd.) SB75) 8.5 parts Toluene 79.0 parts

The seven types of thermal transfer recording media obtained above were stored at 50 ° C. for 36 hours and subjected to a blocking test. The results are shown in Table 2.

[0024]

[Table 2] Blocking test: The thermal transfer recording medium manufactured with the above anchor coat layer is stored for 30 hours in a constant temperature bath at 50 ° C., and after the storage is completed, the thermal transfer recording medium is taken out to test whether the ink layer surface is transferred to the back surface. (Particularly, core of product) Blocking rank: Rank 1 having blocking almost all over the product width and rank 5 having no blocking at all.

As is apparent from Table 2, the smoothness of the surface of the anchor coat layer is 9,000 seconds or more as a Beck value, preferably 10,
By setting the range of 000 seconds or more and 30,000 seconds or less, a thermal transfer recording medium having a high blocking rank can be obtained.

[0026]

As described above, according to the present invention, it is possible to obtain a thermal transfer recording medium in which blocking does not occur even when the resin content in the anchor coat layer is set as low as about 2%.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiro Sato 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd.

Claims (3)

[Claims] 1. A thermal transfer recording medium in which a hot melt type anchor coat layer is provided on a substrate and a solvent dispersion type ink layer is provided thereon, and the surface smoothness of the anchor coat layer is 9,000 seconds or more. A thermal transfer recording medium characterized by the above. 2. The surface smoothness of the anchor coat layer is 1
The thermal transfer recording medium according to claim 1, wherein the thermal transfer recording medium is set to 0000 seconds or more and 30,000 seconds or less. 3. The thermal transfer recording medium according to claim 1, wherein the surface of the anchor coat layer is heat-treated by a heating roll or a heating fan.