JPS61228993A - Thermal fusion transfer recording medium - Google Patents

Abstract

PURPOSE:To enable clear images to be obtained without generating troubles such as voids, by a system wherein a thermal fusion transfer ink layer comprises a coloring agent mixed in a vehicle comprising a wax and a thermoplastic resin having a melt index in a specified range, and the viscosity of the transfer layer at a specified temperature is controlled to a value within a specified range. CONSTITUTION:The thermal fusion transfer ink layer comprises a coloring agent mixed in a vehicle comprising a wax and a thermoplastic resin having a melt index of 1.5-500, and the viscosity of the transfer layer at 90 deg.C is controlled to within the range of 2-100 poise. With this arrangement, it is possible to adhere an ink to recessed parts of a rugged pattern in the condition where fibers are not exposed. If the viscosity is lower than 2 poise or the melt index is more than 500, voids are generated in the images transferred to a recording paper, and density is lowered, whereas if the viscosity is higher than 100 poise or the melt index is less than 1.5, cutting property of the ink layer is poor.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a heat-melt transfer recording medium used to form a printed image of heat-melt transfer ink on recording paper by controlling the heating of a thermal head.

[Prior Art and Problems to be Solved by the Invention] Conventionally, when using this type of heat-melting transfer recording medium, the surface of the recording paper (image forming surface) should be as smooth as possible to produce clear prints. It was said that it could form images.

This is because when an image is formed on plain paper, bond paper, or the like with a surface smoothness of about 50 seconds (Beck smoothness, hereinafter the same) or the like, the image becomes white.

The primary cause of this white spot is that the ink is not transferred to the rough uneven valleys of the recording paper, but in order to eliminate this, the printing energy of the thermal head is increased and the ink is transferred. When the fluidity was increased, the ink penetrated into the recording paper and the fibers of the recording paper were exposed, resulting in white spots.

[Means for solving the problems] In order to solve these problems, as a result of various studies, we found that the hot-melt transfer ink layer is made of wax and a thermoplastic resin with a melt index of 1.5 to 500. By adopting a configuration in which a coloring agent is mixed in a vehicle, and the viscosity of the transfer layer at 90°C is adjusted to 2 to 100 poise, it is possible to prevent ink from adhering to the valleys of unevenness. This can now be done without exposing the fibers.

If the viscosity is less than 2 poise or the melt index of the thermoplastic resin exceeds 500, white spots will appear in the printed image transferred to the recording paper and the density will decrease; If the melt index of the thermoplastic resin exceeds 1.5 or the melt index of the thermoplastic resin is less than 1.5, the ink layer will not cut easily, and for example, when printing the character 0, the ink will be transferred to the inside and cause black dots. There are drawbacks.

[Example] The waxes include paraffin wax, microcrystalline wax, carnauba wax, ceresin wax, oxidized wax, ester wax, polyethylene wax, other natural waxes, and synthetic waxes alone or in combination of two or more. Can be used appropriately.

As the coloring agent, carbon black, organic pigments, inorganic pigments, dyes, etc. can be suitably used alone or in combination of two or more.

As the thermoplastic resin, melt index (AS
THD-1238) is 1.5~SOO, especially 2~
40G is used, for example, vinyl chloride-vinyl acetate copolymer, rosin, polyterpene resin, monoolefin polymer such as ethylene polymer, diolefin polymer, ethylene-acrylate copolymer, cyclo Pentadiene resin, alicyclic hydrocarbon resin, aromatic hydrocarbon resin, phenol resin, styrene resin, coumaron-indene resin, polyamide resin, styrene-vinyl acetate copolymer, etc. alone or in combination of two or more and can be used appropriately.

Furthermore, plasticity may be added if necessary. Examples of the plasticizer include chlorinated paraffin, diethylene glycol dibenzoate, dioctyl phthalate, hydrogenated terphenyl, toethylenetoluenesulfonamide, butyl phthalyl butyl glycolate, cresyl diphenyl phosphate, butyl benzyl phthalate, etc. alone or in combination. More than one species can be mixed and used appropriately.

The mixing ratio of each of these components is 1 to 20 parts by weight of the coloring agent to 20 parts by weight of the wax, and 4 parts by weight of the coloring agent.
-12 parts by weight, thermoplastic resin 1-20 parts by weight, especially 4-12 parts by weight. When adding the plasticizer, add 2 parts by weight to 20 parts by weight of the wax.
A suitable amount is 13 parts by weight, more preferably 2 to 10 parts by weight.

These components are mixed and dispersed using a chill roll or other dispersion mixing device, and the viscosity of the ink at 90°C (
It is preferable to adjust the value measured by a rotational viscometer (Rodovisco) to 2 to 100 poise, particularly 4 to 80 poise.

The thus prepared ink is hot melt coated or solvent coated on one side of the base material to form a heat melt transfer ink layer.

The base material may be polyester film, polyamide film, polyimide film, polypropylene film, polycarbonate film, cellulose triacetate film, cellophane, condenser paper, glassine paper, India paper, etc. with a thickness of 1 to 2 (h+n). Can be used for

The thickness of the ink layer is preferably 1 to 20 o/ffl, particularly 4 to 10 c+/m.

Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 The following components were mixed and dispersed using a chilled roll to obtain an ink having a viscosity of 10 voices at 90°C. Next, the above ink was hot-melt coated onto 6 thick polyester films to form an ink layer with a coating amount of 6 g/end.

The heat-melting transfer recording medium obtained in this way was formed into a ribbon shape, and a thermal transfer printer (Typestar 5) manufactured by Canon was used, and the voltage applied to the thermal head was set to 8.
When an image was formed on bank bond paper with a Bekk smoothness of 10 seconds or less, the ink layer cut well and a clear image with no white spots was obtained.

Ink composition Paraffin wax 5 parts by weight ethylene
Vinyl acetate copolymer (melt index 400) 2 parts by weight Carbon black 1 part by weight Example 2 The following components were mixed and dispersed in a chilled roll to obtain an ink having a viscosity of 2 poise at 90°C. Next, a 6-thick polyester film was hot-melt coated with the ink to form an ink layer with a coating amount of 6 a/d.

Using the heat-melting transfer recording medium thus obtained, a printing test was conducted in the same manner as in Example 1.
As in Example 1, a clear image was obtained on the bank bond paper.

Ink composition Paraffin wax 5 parts by weight Elvaloy 741 (trade name of ethylene polymer manufactured by DuPont Mitsui Polychemicals, melt index 35) 1! Part by weight Carbon black 1 part by weight Example 3 The following components were mixed and dispersed using a chilled roll to obtain an ink having a viscosity of 5 voices at 90°C. Next, the ink was hot-melt coated onto a polyester film having a thickness of 6 Jl to form an ink layer having a coating amount of 6 a/m.

Using the heat-melting transfer recording medium thus obtained, a printing test was conducted in the same manner as in Example 1.
As in Example 1, a clear image was obtained on the bank bond paper.

Ink composition Carnauba wax 5 parts by weight ethylene
Ethyl acrylate copolymer (melt index 30
) 3 parts by weight Carbon black 2 parts by weight Example 4 The following components were mixed and dispersed using a chill roll to obtain an ink having a viscosity of 3 poise at 90°C. Next, the ink was hot-melt coated onto a polyester film having a thickness of 6ts to form an ink layer having a coating amount of 6a/-tri.

Using the heat-melting transfer recording medium thus obtained, a printing test was conducted in the same manner as in Example 1.
As in Example 1, the bank bond paper gave a clearer impression.

Ink composition Carnauba wax 4 parts by weight Vinyl chloride-vinyl acetate copolymer (melt index 30) 3 parts by weight Carbon black 2 parts by weight Chlorinated paraffin 1 part by weight When applied to printing, a clear printed image was obtained in the same way as above.

[Effects of the Invention] When the heat-melting transfer recording medium of the present invention is used, a clear printed image can be obtained on recording paper with low smoothness without causing problems such as white handling.

Claims (1)

[Claims] 1. In a hot-melt transfer recording medium in which a hot-melt transfer ink layer is provided on one side of a base material, the hot-melt transfer ink layer is formed in a vehicle consisting of wax and a thermoplastic resin having a melt index of 1.5 to 500. A coloring agent is mixed therein, and the viscosity at 90°C of the transfer layer is 2.
A heat-melting transfer recording medium characterized by being adjusted to ~100 poise.