JPH07101170A - Thermal transfer image receiving sheet - Google Patents

Abstract

PURPOSE:To absorb ink whole holding smoothness of a surface layer of an image receiving sheet when a melt type thermal printing is conducted and to record via density gradation by coating a base material with a coating solution containing binder resin and plastic pigment as main ingredients, drying it and providing an image receiving layer. CONSTITUTION:An image receiving layer formed by coating a base material with a coating solution containing one type or more of binder resin selected from a group consisting of polyester resin, vinyl chloride resin, vinyl acetate resin, acrylic resin, polyethylene resin, polyurethane resin, and vinylidene chloride resin, and spherical plastic pigment having a particle size of 0.4-5mum as main ingredients in such a manner that a composition ratio of the pigment/the resin is by weight 1.5/1-8/1 is provided on the base material. A void volume of the pigment is set to 10% or less. That is, since it has a microporous layer which is smooth and contributes to ink absorption properties, it can perform a density gradation and is optimum for full-color thermal transfer printing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer image receiving paper useful for printing electronic images of video, television, color graphics and the like in full color.

[0002]

2. Description of the Related Art Recently, needs for color copying machines, color printers and the like have increased, and attention has been paid to fusion type thermal transfer printers, sublimation type thermal transfer printers and the like.

In melt-type thermal transfer printing, heat supplied from a thermal head in response to an electric signal of an image causes
Since the ink is transferred in a liquid state, when performing multi-gradation recording, the image receiving paper has an ink absorption layer while maintaining the smoothness, thereby enabling density gradation.

Further, in full-color printing, various colors are expressed by superposing a single color of ink, and therefore, if the image receiving layer is not absorptive, a transfer failure may occur in the second and subsequent colors.

In the case of a general smooth image receiving paper which does not absorb ink, multi-gradation recording is performed by controlling the ink adhering area, but sufficient multi-gradation characteristics are still obtained. Absent.

In order to obtain a smooth surface and absorbability of ink, there is a method of using a polymer blend or a special coagulation method to obtain a porous layer at the time of coating, but since it is a special production method, Low productivity, unable to coat on paper,
It has drawbacks such as high cost.

[0007]

SUMMARY OF THE INVENTION Therefore, the present invention provides a fusion type resin by combining a binder resin and spherical plastic pigments to provide an image receiving layer having a microporous layer for absorbing ink while maintaining the surface smoothness. An object of the present invention is to provide an image receiving paper capable of multi-gradation recording by expressing density of ink in thermal transfer printing.

[0008]

The present invention will be described in detail below.

Examples of the substrate used in the present invention include plain paper, coated paper, plastic film, synthetic paper and the like.

The plastic film may have voids inside or may be made opaque by adding a filler. The film or synthetic paper may be attached to the paper.

In order to improve the adhesion and the wettability, those subjected to corona treatment or easy adhesion treatment may be used.

When plain paper or coated paper is used as the base material of the image-receiving paper of the present invention, chlorinated polypropylene, for example, is used as a filling layer under the image-receiving layer in order to prevent waviness due to permeation of the aqueous coating liquid. It is preferable to coat the coating with 1 to 2 μm.

Examples of the binder resin for the image receiving paper of the present invention include polyester resin, vinyl chloride resin, vinyl acetate resin, acrylic resin, polyethylene resin, polyurethane resin and vinylidene chloride resin. Is a vinyl chloride homopolymer or a copolymer containing 50% or more of vinyl chloride. Examples of the copolymer include vinyl chloride-vinyl acetate resin and vinyl chloride-acrylic resin.

The vinyl acetate resin is a vinyl acetate homopolymer or a copolymer containing 50% or more of vinyl acetate. Examples of the copolymer include vinyl acetate-ethylene resin and vinyl acetate-ethylene-vinyl chloride. Resin etc.

A combination of these resins and a plastic pigment forms a microporous layer that absorbs ink.

When the adhesiveness between the base material and the image receiving layer is insufficient, an undercoat layer can be provided on the base material in advance.

The resin of the undercoat layer is not limited, and examples thereof include polyester resins, polyamide resins,
Examples thereof include acrylic resin, styrene resin, vinyl resin, olefin resin, polycarbonate resin, phenol resin, urea resin, urethane resin and melamine resin.

The plastic pigment of the image-receiving layer of the present invention is a spherical water-dispersion type, and for example, acrylic-styrene copolymer resin, styrene resin, benzoguanamine resin, melamine resin and the like are preferable.

The shape of the particles is preferably a spherical shape having a narrow particle size distribution in order to make the surface rough and make a uniform porous structure.

The resin type of the water-dispersed plastic pigment is not limited, and the conditions of average particle size and particle size distribution are such that the average particle size is 0.5-5 μm, preferably 0.7-2.
The particle size distribution is 90% or more in 1 μm before and after the average particle size, and the particle size distribution is sharp.

If it is smaller than 0.5 μm, a microporous layer sufficient for ink penetration cannot be formed, and if it is larger than 5 μm, the smoothness of the coating layer is deteriorated, and the gap between the plastic pigment particles is too large. Resulting in excessive absorption and loss of image gloss.

If a plastic pigment having a porosity in the pigment sphere of more than 10% is used, it tends to be crushed,
When the particle size is large, and when the porosity is large, the effect is remarkable.

In other words, due to calendering or other pressure, or due to the pressure of the thermal head during thermal transfer printing, the formed microporous layer loses its uniformity, impairs the ink absorbability, or becomes nonuniform. As a result, the image quality deteriorates.

The weight ratio of spherical plastic pigment / binder resin solid content must be 1.5 to 1 to 8/1.

It is important that when the plastic pigment is filled in the layer, a gap is formed between the particles, and the amount of the binder may fill the gap, or the binder may not cover the surface layer to form a film. is necessary.

When the amount of the binder is more than 1.5 / 1, the gap for absorbing the ink is filled, and when the amount of the binder is less than 8/1, the adhesion may be deteriorated or the surface layer may be fragile.

Further, in order to improve the coating suitability, other components such as a thickener, a wetting agent, a defoaming agent and a small amount of filler may be added to the coating liquid.

It is sufficient that the dry thickness of the image receiving layer is 1 μm or more, but in consideration of the sharpness of the image and the economical efficiency, it is 5
-30 μm is preferable.

As the coating method, various methods such as reverse roll coating, air knife coating and gravure coating can be used.

[0030]

【Example】

[0031]

[Example 1] Continuous amount (weight of paper, forty-six size paper 1
Represents the weight of 000 sheets. ) 110 kg of cast-coated paper was coated with 2 μm of chlorinated polypropylene (which is a sealing layer and also functions as an undercoat layer).

A coating liquid having the following composition-1 was applied to this with a wire bar and dried to form an image receiving layer having a thickness of 15 μm. Parts are parts by weight (hereinafter the same).

Composition-1 Vinyl acetate resin (Movinyl 114, manufactured by Hoechst Synthetic Co., Ltd.) 100 parts Spherical plastic pigment (SX-866G02, particle size 0.97 μm, polystyrene resin manufactured by Japan Synthetic Rubber Co., Ltd.) 240 parts

[0034]

Comparative Example 1 A cast coated paper having a continuous amount of 110 kg was coated with chlorinated polypropylene in a thickness of 2 μm.

A coating solution having the following composition-2 was applied to this with a wire bar and dried to form an image receiving layer having a thickness of 15 μm.

Composition-2 Carboxylated styrene-butadiene resin (L-1518, manufactured by Asahi Kasei Corporation) 100 parts Spherical plastic pigment (SX-866G02, particle size 0.97 μm, manufactured by Japan Synthetic Rubber Co., Ltd.) 240 parts

[0037]

Example 2 A 75 μm thick foamed polyester film that had been subjected to an easy-adhesion treatment was coated with a coating liquid having the following composition-3 using a wire bar and dried to form an image receiving layer having a thickness of 10 μm.

Composition-3 Acrylic resin (Movinyl 908, manufactured by Hoechst Synthetic Co., Ltd.) 100 parts Hollow spherical plastic pigment (Rhopaque HP-91, particle size 1.0 μm, styrene-acrylic resin manufactured by Hoechst Synthetic Co., Ltd.) 300 parts

[0039]

Comparative Example 2 A 75 μm thick foamed polyester film which had been subjected to an easy-adhesion treatment was coated with a coating liquid of the following composition-4 using a wire bar and dried to form an image receiving layer having a thickness of 10 μm.

Composition-4 Styrene-Butadiene resin (Nipol LX407K, manufactured by Nippon Zeon Co., Ltd.) 100 parts Hollow spherical plastic pigment (Lowpake HP-91, particle size 1.0 μm, manufactured by Hoechst Synthetic Co., Ltd.) 300 parts

[0041]

Example 3 A cast coated paper having a continuous weight of 110 kg was coated with chlorinated polypropylene in a thickness of 2 μm.

A coating solution having the following composition-5 was applied to this with a wire bar and dried to form an image receiving layer having a thickness of 5 μm.

Composition-5 Polyethylene resin (Sixen L, manufactured by Sumitomo Seika) 100 parts Spherical plastic pigment (SX-866G02, particle size 0.97 μm, manufactured by Japan Synthetic Rubber Co., Ltd.) 480 parts

[0044]

Example 4 A cast coated paper having a continuous weight of 110 kg was coated with 2 μm of chlorinated polypropylene.

A coating solution having the following composition-6 was applied to this with a wire bar and dried to form an image receiving layer having a thickness of 10 μm.

Composition-6 Polyester resin (Peth Resin A-210, manufactured by Takamatsu Yushi Co., Ltd.) 100 parts Spherical plastic pigment (SX-866G01, particle size 0.72 μm, manufactured by Japan Synthetic Rubber Co., Ltd.) 600 parts

[0047]

Example 5 A cast coated paper having a continuous amount of 110 kg was coated with 2 μm of chlorinated polypropylene.

A coating solution having the following composition-7 was applied to this with a wire bar and dried to form an image receiving layer having a thickness of 10 μm.

Composition-7 Polyurethane resin (Hydran AP-40, manufactured by Dainippon Ink and Chemicals, Inc.) 100 parts Spherical plastic pigment (SX-866G02, particle size 0.97 μm, manufactured by Japan Synthetic Rubber Co., Ltd.) 800 parts

[0050]

Example 6 A 75 μm-thick white polyester film that had been subjected to an easy-adhesion treatment was coated with a coating solution having the following composition-8 using a wire bar and dried to form an image-receiving layer having a thickness of 20 μm.

Composition-8 vinyl chloride-vinyl acetate resin (Vinibrand 240, manufactured by Nisshin Chemical Industry Co., Ltd.) 100 parts Spherical plastic pigment (SX-866G01, particle size 0.72 μm, manufactured by Japan Synthetic Rubber Co., Ltd.) 260 parts

[0052]

Comparative Example 3 A 75 μm-thick white polyester film that had been subjected to an easy-adhesion treatment was coated with a coating liquid having the following composition-9 using a wire bar and dried to form an image-receiving layer having a thickness of 20 μm.

Composition-9 Styrene-acrylic resin (Movinyl 728, Hoechst Synthetic Co., Ltd.) 100 parts Spherical plastic pigment (SX-866G01, particle size 0.72 μm, Japan Synthetic Rubber Co., Ltd.) 260 parts

[0054]

Example 7 A 100 μm-thick synthetic paper over laminated with polypropylene films on both sides was coated with 2 μm of chlorinated polypropylene.

A coating solution having the following composition-10 was applied to this with a wire bar and dried to form an image receiving layer having a thickness of 10 μm.

Composition-10 Vinyl Chloride-Acrylic Resin (Vinibrand 270, Nisshin Chemical Industry Co., Ltd.) 100 parts Spherical plastic pigment (SX-866G02, particle size 0.97 μm, Japan Synthetic Rubber Co., Ltd.) 300 parts

[0057]

Example 8 A cast coated paper having a continuous amount of 110 kg was coated with 2 μm of chlorinated polypropylene.

A coating solution having the following composition-11 was applied to this with a wire bar and dried to form an image receiving layer having a thickness of 15 μm.

Composition-11 Vinyl acetate-ethylene-vinyl chloride resin (Sumikaflex 850, Sumitomo Chemical Co., Ltd.) 100 parts Spherical plastic pigment (SX-866G02, particle size 0.97 μm, Japan Synthetic Rubber Co., Ltd.) 240 parts

[0060]

Example 9 A cast coated paper having a continuous amount of 110 kg was coated with 2 μm of chlorinated polypropylene.

A coating liquid having the following composition-12 was applied to this with a wire bar and dried to form an image receiving layer having a thickness of 15 μm.

Composition-12 Vinylidene chloride resin (Diophan YJ2076D, manufactured by Mitsubishi Petrochemical Badishe) 100 parts Spherical plastic pigment (SX-866G02, particle size 0.97 μm, manufactured by Japan Synthetic Rubber Co., Ltd.) 240 parts

[0063]

Example 10 A cast coated paper having a continuous amount of 110 kg was coated with 2 μm of chlorinated polypropylene.

A coating liquid having the following composition-13 was applied to this product with a wire bar and dried to form an image receiving layer having a thickness of 7 μm.

Composition-13 Acrylic resin (Primal AC-382, manufactured by Japan Acrylic Co., Ltd.) 100 parts Spherical plastic pigment (SX-866G02, particle size 0.97 μm, manufactured by Japan Synthetic Rubber Co., Ltd.) 150 parts

[0066]

Comparative Example 4 A cast coated paper having a continuous amount of 110 kg was coated with 2 μm of chlorinated polypropylene.

A coating solution having the following composition-14 was applied to this with a wire bar and dried to form an image receiving layer having a thickness of 7 μm.

Composition-14 Acrylic resin (Primal AC-382, manufactured by Japan Acrylic Co., Ltd.) 100 parts Spherical plastic pigment (SX-866G02, particle size 0.97 μm, manufactured by Japan Synthetic Rubber Co., Ltd.) 100 parts

[0069]

Example 11 A cast coated paper having a continuous amount of 110 kg was coated with 2 μm of chlorinated polypropylene.

A coating liquid having the following composition-15 was applied to this product with a wire bar and dried to form an image receiving layer having a thickness of 15 μm.

Composition-15 Acrylic resin (Primal AC-382, manufactured by Nippon Acrylic Co., Ltd.) 100 parts Hollow spherical plastic pigment (Rhopaque OP-84J, particle size 0.55 μm, manufactured by Rohm and Haas) 260 parts

[0072]

Comparative Example 5 A cast coated paper having a continuous amount of 110 kg was coated with 2 μm of chlorinated polypropylene.

A coating solution having the following composition-16 was applied to this with a wire bar and dried to form an image receiving layer having a thickness of 15 μm.

Composition-16 Acrylic resin (Primal AC-382, manufactured by Nippon Acrylic Co., Ltd.) 100 parts Spherical plastic pigment (Grandall PP1000, particle size 0.4 μm, styrene-acrylic resin manufactured by Dainippon Ink and Chemicals, Inc.) 260 parts

[0075]

Example 12 A 75 μm thick white polyester film that had been subjected to an easy-adhesion treatment was coated with an undercoat liquid of acrylonitrile-styrene resin: toluene = 1: 4 with a wire bar.
It was dried to form a 2 μm undercoat layer.

Further, the coating solution of composition-8 of Example 6 was applied with a wire bar and dried to form an image receiving layer of 20 μm.

The above-mentioned thermal transfer image-receiving papers of Examples and Comparative Examples of the present invention were printed by a fusion type full color printer (HC-3600, manufactured by JRC) using an ink sheet having a coating amount of 2.0 g / m ^2. , Compare the images obtained,
The results in the table were obtained.

[0078]

[Table 1]

The evaluation method of the examples was performed as follows. (1) Ink absorbency Solid printing was performed with a single color, and the gloss of the ink after transfer was visually observed. ⊚: Absorbs ink and has a high matte property (low gloss). ◯: Absorbs ink slightly and has a low matte property. X: No ink is absorbed and no matte is formed.

(2) Image quality Full-color printing is performed, density gradation of ink dots,
And the omission of the overlapping portion of the dots was visually confirmed. ⊚: The density gradation is very good and there is no omission. ◯: The density gradation is good and there is almost no omission. X: Poor density gradation causes omission.

[0081]

The thermal transfer image-receiving paper of the present invention has a fine porous layer which is smooth and contributes to the ink absorbability due to the combination of the binder resin of the image-receiving layer and the plastic pigment. Most suitable for thermal transfer printing.

Claims (2)

[Claims] 1. One or more binder resins selected from the group consisting of polyester resin, vinyl chloride resin, vinyl acetate resin, acrylic resin, polyethylene resin, polyurethane resin and vinylidene chloride resin on a substrate. And a spherical plastic pigment having a particle size of 0.4 to 5 μm as a main component, and a coating liquid having a spherical plastic pigment / binder resin composition ratio of 1.5 / 1 to 8/1 by weight is applied. A thermal transfer image-receiving paper characterized in that an image-receiving layer is provided. 2. The thermal transfer image receiving paper according to claim 1, wherein the spherical plastic pigment has a porosity of 10% or less.