JPS59165690A - Thermal transfer medium - Google Patents

Abstract

PURPOSE:To provide a thermal transfer medium capable of being stably used for thermal transfer multiple times while preventing a recording layer from being exfoliated, wherein an adhesive layer consisting of nitrocellulose, acetylcellulose or the like is provided between a base and a heat-fusible ink layer. CONSTITUTION:First, an adhesive consisting of nitrocellulose, acetylcellulose, cellulose acetate butylate and/or cellulose propionate is applied onto a base (e.g., a condenser paper) to provide an adhesive layer in a thickness of preferably 0.05-8mum, and then a heat-fusible ink layer is provided thereon to obtain the objective medium. The heat-fusible ink may be, e.g., a material comprising a heat-fusible solid component such as carnauba wax and a coloring component such as carbon black in a resin such as PVC.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a thermal transfer medium for use in printers, plotters, and the like.

Conventional heat-sensitive recording methods have been widely put into practical use due to their ease of handling, low cost, and storage stability. However, once the heat-sensitive transfer medium is used, the ink composition applied on the base material is transferred to the recording sheet. There was a drawback that it moved completely upwards.

Therefore, recording media equipped with a recording layer that can be thermally copied many times have been developed, but either no adhesive layer is used between the base material and the recording layer, or resins such as acrylic, which are well-known as adhesives, are used. If the recording layer is used, the recording layer may peel off during the first transfer, making it impossible to perform the second and subsequent transfers.

Purpose The present invention aims to prevent peeling of the recording layer and to stably perform thermal transfer many times, which is the original purpose.

Structure The present invention provides a heat-sensitive transfer medium in which an adhesive layer is provided on a base material and a heat-melt ink layer is provided on the adhesive layer, in which the adhesive layer is made of one of nitrocellulose, acetylcellulose, cellulose acetate butyrate, and cellulose propionate. species or two
The gist of the present invention is a heat-sensitive transfer medium comprising at least one species.

In other words, as a result of repeated research on many resin-based adhesives, we found that nitrocellulose, acetylcellulose, cellulose acetate-1 to butyrate-1-, and cellulose propionate are optimal as adhesives for thermal transfer media for multiple transfers. The present invention was made based on this discovery.

The above resins may be used alone or in combination, and the thickness of the adhesive layer is 0.
．． A range of 0.05 to 8 μm is suitable.

These resins have strong adhesive strength, so the recording layer does not peel off even after multiple transfers, and since the adhesive layer can be formed thin, thermal transfer can be carried out efficiently without significantly reducing thermal conductivity. can.

The heat-melting ink layer may be one containing a heat-melting solid component and a coloring agent component in a microporous resin layer, or one containing a solvent dye, a low melting point compound, and a fine powder such as carbon black.

In the former example, the resin includes polyvinyl chloride, polyvinyl acetate, polyvinyl fluoride, polyvinyl butyral, polyvinylidene chloride, polyvinyl alcohol,
Vinyl chloride/vinyl acetate copolymer, vinyl chloride/vinyl acetate copolymer
Vinyl resins such as vinylidene chloride copolymers, acrylic resins such as polyacrylic esters and polymethacrylic esters, ethyl cellulose, cellulose acetate, etc.
1i-based resin, polystyrene, polyethylene,
Polyethylene/vinyl acetate copolymer, polyamide, A
Examples include BS resin, gelatin, gum arabic, and the like. Further, heat-melting solid components or low-melting point compounds include paraffin wax, microcrystalline wax, ceresin wax, carnauba wax, ceresin wax, polyethylene wax, oxidized polyethylene wax, castor wax, tallow hydrogenated oil, Carbowax, wood wax, lanolin, stearic acid monoglyceride, sorbitan monostearate, sorbitol hexastearate, pentaerythritol stearate, polyoxyethylene monostearate, stearyl alcohol, other synthetic oxidized waxes, synthetic and natural ester waxes, There are hydrogenated waxes, etc.

Examples of the coloring agent include carbon black, lake red, alkali blue, and crystal violet lactone. Examples of solvent dyes include anthraquinone dyes and azo dyes.

As the base material, 11 papers such as capacitor paper and glassine paper, polymer films such as polyamide film, polyimide film, and polyester filmate film can be used.

Next, examples and comparative examples will be described.

Example 1 Acetyl cellulose (trade name L-70, manufactured by Daicel Chemical Industries, Ltd.) was dissolved in acetone, and the thickness after drying was 1 μm.
It was coated on a support made of 15 μm capacitor paper so that

Example 2 Cellulose acetate butyrate (reagent manufactured by Kanto Kagaku ■) was dissolved in aretone and coated on a support made of 15 μm capacitor paper so that the thickness after drying was 1 μm.

Comparative Example 1 Only a support made of capacitor paper with a thickness of 15 μm was used.

Comparative Example 2 Acrylic resin (trade name: Dianal LR-396, manufactured by Mitsubishi Rayon ■) was dissolved in toluene and coated on a support made of 15 μm capacitor paper so that the thickness after drying was 1 μm.

Separately, an ink liquid was prepared as follows.

0 Carnauba wax 7 Castor wax 11 Carbon black
4 Ethyl acetate 51 Toluene
17 First, carbon black, carnauba wax, and -0- castor wax are mixed at 85°C and thoroughly kneaded using a three-roll mill to prepare an ink component.

On the other hand, vinyl chloride/vinyl acetate copolymer, ethyl acetate, and toluene were placed in a ball mill and stirred at 50°C for 1 hour to completely dissolve the vinyl chloride/vinyl acetate copolymer. Next, the above-mentioned ink components were added thereto and stirred for 2 hours to obtain a smooth and uniformly dispersed ink solution, thereby preparing an ink solution.

This ink liquid was applied to the above Examples and Comparative Examples, and ethyl acetate and toluene were evaporated to form a heat-melting ink layer to obtain a heat-sensitive transfer medium.

Using the four types of samples obtained above, use the Rifax 3300
(■ manufactured by Ricoh) was used for thermal transfer. A two-fold test was also conducted on these samples. In this case, in the two-fold test, the sample was folded in half with the ink layer inside, and the adhesion between the ink layer and the support at the folded line was visually judged, and if it did not peel off, it was judged as good, and if it peeled off, it was judged as poor. . The results of these tests are shown in the table.

Table No. Transfer test 1-2 fold test 1~ Example 1 Can be transferred 10 times Good example 2
Possible to transfer 10 times Good comparative example 11 times transfer causes solid area to peel off 2 times transfer causes solid area torn transfer Poor comparative example 21 times transfer causes solid area to peel off 2 times transfer causes solid area torn transfer Good effect Recording layer peels off during transfer Since this does not occur, multiple transfers are possible, and since the adhesive layer can be made thinner, a clear transferred image can be obtained without greatly reducing thermal conductivity.

Patent applicant: Ricoh Co., Ltd. Agent: Patent attorney Hidetake Komatsu

Claims (1)

[Claims] (1) In a thermal transfer medium in which an adhesive layer is provided on a base material and a heat-melt ink layer is provided on the adhesive layer, the adhesive layer is made of one of nitrocellulose, acetylcellulose, cellulose acetate butyrate, cellulose propionate, or 2
A heat-sensitive transfer medium characterized by comprising more than one species.