JPS61273989A - Thermal transfer sheet - Google Patents

Abstract

PURPOSE:To develop background staining preventing effect and the good abrasion resistance of printed matter, by providing a heat-meltable release layer containing wax, a colored layer containing no wax and a heat-meltable adhesive layer containing wax in this order from a support side. CONSTITUTION:A heat-meltable release layer 2 containing at least 90% or more of wax is provided on a support 1 such as polyester or cellophane and a colored layer 3 consisting of a resin binder at least containing no wax and a coloring material is provided on said layer 2 and a heat-meltable adhesive layer 4 containing at least 90% or more of wax is provided on the layer 3. Each of the coating amounts of the layers 2, 3, 4 is properly about 1g/m<2> and the abrasion resistance of a printing surface can be enhanced by the ink colored layer 3 using the resin to make it possible to make the colored layer thin. In order to provide the action for preventing a background staining phenomena and the action for enhancing the close adhesiveness to image receiving paper at the time of heating, the translucent adhesive layer 4 containing a large amount of wax is provided on the colored layer 3.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a thermal transfer sheet capable of printing on a wide range of image-receiving papers, from smooth paper to rough paper.

In recent years, the thermal transfer recording method using a thermal head has become widely used due to its advantages such as being relatively inexpensive, compact, and easy to maintain. However, only paper with high smoothness can be used to form images by thermal melt transfer, resulting in high costs and limited applications.

(Prior art) Conventionally, heat-sensitive transfer type sheets have been produced using a heat-resistant film (51) such as polyester or other heat-resistant film (51) with a thickness of 6 to 10 microns, a colored layer made by mixing pigments with wax or the like to form a hot melt ink, or an organic solvent. or aqueous emulsion colored layer (
6) is produced by printing or coating, and because the binder composition is mainly wax, it has poor affinity for coloring materials such as pigments, and has poor bonding strength to image-receiving paper, making it extremely thick ((5 to 6). Transfer density could not be obtained without 4μ).On the other hand, because the first colored layer was thick and brittle, the abrasion resistance was low (
During printing, the white base of the image receiving paper is likely to be contaminated (background smudge). Another disadvantage is that the printed image is easily removed by friction with fingers or the like.

On the other hand, conventional thermal transfer sheets require smooth paper with very few irregularities (Peck air permeability tester: 400 seconds) as image receiving paper, and rough paper with significant irregularities (Peck: 20 seconds or less).
The transfer density is low (single image reproducibility is also low).

(Problems to be Solved by the Invention) The present invention solves the drawbacks of conventional heat-sensitive transfer sheets consisting of a colored layer mainly made of wax, namely, contamination of the white base of the non-image area of the image-receiving paper during printing. to do.

This is an attempt to solve the problem that the abrasion resistance of printed matter is extremely low, and that the density of printing on rough paper with significant irregularities is low and unclear.

(Means for solving the problem) The present invention has changed the conventional colored layer mainly composed of wax, and forms the colored layer entirely with a resin that does not contain wax.
A release layer, a colored layer that does not contain wax, and an adhesive layer are provided to prevent contamination of the white paste in the non-printed area and to improve the abrasion resistance of the printed area.

The gist of the present invention is to provide, on a support such as a polyester resin, a heat-fusible release layer containing wax, a colored layer containing no wax, and a heat-fusible adhesive layer containing wax in order from the support side. This is a heat-sensitive transfer sheet characterized by:

To explain the present invention in detail according to examples, the thermofusible release layer is made of wax and a binder, and the wax content is 90%
The wax-free colored layer contains dye or pigment and a resin binder as main components, and the binder is a resin such as acrylic, polyamide, or polyester.

It is made into ink by kneading it with a solvent.

The adhesive layer consists of wax and resin binder.

Contains 90% by weight or more of wax. The wax contained in the release layer and adhesive layer is 50°C to 150°C.
It has a melting point of either Also, the degree of decrease in cohesive force between the adhesive layer and @release layer due to the thermal head at the time of printing is set so that the release layer has a greater degree of decrease.

Selection of wax or thickness of both layers and colored layer.

This is used to set the thickness of the support. FIG. 1 is a cross-sectional view of the laminated layers of one embodiment of the heat-sensitive transfer sheet of the present invention, in which a thermofusible release layer (2) containing at least a wax having a coefficient of 90 or more is provided on a support material (11) made of ant, polyester, cellophane, etc. , a colored layer (3) consisting of a small amount (not including wax) of a resin binder and a coloring material is provided on the layer (2);
3) Provide a thermofusible adhesive layer (4) containing wax with a width of at least 90 mm or more on top. The wax in the above structure is selected from those having a melting point in the range of SO'C to 150 DEG C. and is used with a suitable melting point. The present invention is carried out according to the prescription described later. Furthermore, in the present invention,
The adhesive layer that adheres to the receiver paper should be applied to a thickness of 1 to 5 microns.

In addition, in the present invention, as explained in the laminated cross-sectional view of another embodiment in FIG. ) can be implemented in a multi-layer configuration, such as a three-layer structure consisting of three layers.

As the above-mentioned peeling layer (2), various types of 506C to 150C
Contains a wax with a melting point of 90% or higher (carnauba wax, montan wax, campria wax, microcrystalline, rice wax, paraffin wax, etc.), and contains a few ounces of ethylene vinyl acetate etc. to give it fluidity. You can do it.

Next, general pigments, dyes, and oil-soluble dyes can be used as color materials for the ink coloring layer, and thermoplastic resins such as acrylic, polyamide, polyester, and chlorinated rubber can be used as binders to disperse and bind these. . Wax has weak binding strength.

When used in the ink layer, it tends to be low density and thick.

do not use. The ink layer in the present invention is highly concentrated.

This is because it is necessary to make the layer thinner.

Next, the adhesive layer (4) contains 90 or more types of waxes with a melting point of 50°C to 150°C (carnauba wax, montan wax, candelilla wax, microcrystalline, rice wax, paraffin wax, etc.) and has a fluidity. Ethylene vinyl acetate, polyamide, etc. can be used in order to provide the desired properties.

The coating amount for each of the above layers +21 +31 +41 is approximately 1
! j/m is appropriate.1For example, the ink colored layer (3) is α
5 g to t OfJ/m is suitable, but good printing strength can be achieved by setting the coating amount of the adhesive layer (4) to 1 to 4 g/m depending on the increase in surface roughness of the receiver paper used. can get.

(Function of the Invention) The present invention can improve the abrasion resistance of the printed surface by using an ink colored layer (3) containing pigments and dye coloring materials dispersed therein and using acrylic or polyester resin with strong binding power. It would be possible to make the colored N1131 thinner.

On the other hand, a large amount of semi-transparent wax is used to prevent the so-called background smudge phenomenon that contaminates the image-receiving paper space in non-printing areas during printing, and to improve adhesion to the image-receiving paper when heated. an adhesive layer (4) containing the colored layer (3) is provided on the colored layer (3);
This can be achieved.

Furthermore, in the conventional structure in which the colored layer is exposed on the surface after printing, the colored layer may be destroyed by friction caused by fingers or clothing. A release layer (2) containing a large amount of wax is provided between the ink colored layer (3) and the support (1), which has the effect of increasing printing efficiency.

In addition, the present invention has a structure in which the ink colored layer (31 is made thinner),
Adhesive layer (
4) and a release layer (2).

(Effects of the Invention) The present invention can exhibit scumming prevention effects and good abrasion resistance of printed materials, which cannot be obtained with a transfer sheet having only an ink colored layer containing wax as a main component.

<Example 1> Prescription ■ (Peeling varnish) Weight line wax & 1 (manufactured by Noda Wax) 15 Montan wax 6715 (Kato Yoko W) 1s Sumichi) KA-10 (ethylene vinyl acetate) (manufactured by Sumitomo Chemical)
1. Toluene, methyl ethyl ketone (MEK), and methyl imbutyl ketone (MIBK) (mixed solvent) of 69 or more were kneaded for 10 hours while heating to 70° C. in a ball mill to form a varnish.

Prescription ■ (Colored ink) Part by weight Acrylic resin BR-105 (Mitsubishi Rayon) 8 Acrylic resin BR-85 (Mitsubishi Rayon) 5
Sumitate KA-10 (ethylene vinyl acetate) (manufactured by Sumitomo Chemical) 2 Liponox NA (anion activator) (manufactured by Dai-Kogyo Seiyaku) 0.5 Bomb blank (#100) 7 Toluene, methyl ethyl ketone (MEK).

Ethyl acetate (mixed solvent)
77.5 or more was milled in a ball mill for 24 hours and made into ink.

Prescription ■ (Adhesive varnish) Parts by weight Rice Wax Man (manufactured by Kokura Gosei) 15 Carnauba wax (manufactured by Kato Yoko) 10 Sumitate KA-10 (ethylene i [vinyl) (manufactured by Sumitomo Chemical) 1 Toluene, methyl ethyl ketone (MEK), methyl Inbutyl ketone (MIBK) (mixed solvent) 74 or more was heated to 70° C. in a ball mill and kneaded for 10 hours to form a varnish.

Gravure peta plate (20μ depth) with prescription release varnish on 6μ thick polyester stretched film (Lumirror manufactured by Toshi)
5 Next, on top of that, print black colored ink with the formula ■ (solvent mixing ratio, toluene 7 : MEK 2 : ethyl acetate 1) with a gravure solid plate (15 μ depth), and then print the formula ■ (solvent Mixing ratio, toluene 7:MEKl:MI
BK2) adhesive varnish was printed using a gravure plate (25μ depth) to create a transfer sheet with 5Ni.

This was superimposed on a highly smooth image receiving paper (Mitsubishi Paper TTR-T: Peck 460 seconds) and transferred and printed (α5 at 2m sec) using a thermal transfer recording machine (Toshiba - Marchemirator).
(mj/dat conditions) - Good solid printed matter was obtained. When this was set in a Gakushin type friction tester and a dry friction test was performed 10 times (200g load) using cotton cloth 1004 (Kinkin No. 5), the degree of contamination with the cotton cloth was 4 to 4.
It was grade 5, which was very good. Incidentally, conventional products, including commercially available products, exhibit a degree of contamination of 1st to 2nd class.

<Example 2> The release varnish of the above formulation (2) was printed on a 4μ thick polyester film (Mirror manufactured by Toshi) using a gravure plate (20μ depth), and then the above formulation (2) (solvent mixing ratio, toluene) was printed on it. 7 : MgK2 : Ethyl acetate 1) black colored ink was printed with a gravure plate (15 μm depth), and then the above formulation (solvent mixing ratio, toluene 7 : MEKl) was printed on top of it.
:MIBK2) adhesive varnish on gravure peta version (25μ
A transfer sheet was created by overprinting 5 times at different depths for a total of 5 layers. This is coated with rough receiving paper (
Maruzen typewriter paper; bond paper, 2, manufactured by Cermil Co., Ltd., Peck 20 seconds), and transfer printing (2 m5e) using a thermal transfer recording machine (Maruzi Tamemirator, manufactured by Toshiba).
c under the condition of α5mj/dat), a good peta print was obtained.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the laminated layers according to the present invention, FIG. 2 is a cross-sectional view of the laminated layers according to another embodiment of the present invention, and FIG. 3 is a cross-sectional view of the laminated layers of a conventional example.

Claims (1)

[Scope of Claims] 1) On a support such as a polyester resin, in order from the support side, a thermofusible release layer containing wax, a colored layer not containing wax, and a thermofusible release layer containing wax. A heat-sensitive transfer sheet characterized by having an adhesive layer. 2) The heat-sensitive transfer sheet according to claim 1, wherein the release layer is made of wax and a binder and contains 90% by weight or more of wax. 3) The heat-sensitive transfer sheet according to claim 1, wherein the colored layer comprises a binder such as acrylic resin, polyamide resin, or polyester resin, and dye or pigment. 4) The thermal transfer sheet according to claims 1 and 2, wherein the adhesive layer is made of wax and a binder and contains 90% by weight or more of wax. 5) The wax contained in the release layer and adhesive layer is 50℃~1
Claim 1 having a melting point of 50°C;
2. The heat-sensitive transfer sheet described in 4. 6) The heat-sensitive transfer sheet according to claim 1, wherein the adhesive layer has a layer thickness in the range of 1 to 5 μm and has a multilayer structure.