JPH0453715B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a sublimation type printing method in which an image is formed by subliming and transferring the sublimable dye from a transfer body provided with a transfer layer containing the sublimable dye by heating. This invention relates to a thermal transfer recording receptor.

[Prior Art] The sublimation thermal transfer recording method enables color recording with high gradation reproducibility by sublimating and transferring a plurality of types of dyes having different sublimation temperatures and hues by changing the heating temperature. There is a strong need for multicolor gradation reproduction in hard copies of still images on television screens and images on computer graphics screens.
In contrast, this method is extremely suitable as it has a high transfer speed and a compact and inexpensive device.

This method, which is particularly rich in gradation, will have many applications in the future, and is expected to be widely used not only for industrial purposes but also for home use, as information media and decorative items.

BACKGROUND ART Conventionally, a receptor used for sublimation type thermal transfer recording is constructed by providing a receiving layer on the surface of a base material, the main component of which is a synthetic resin that can be dyed with a sublimable dye. The base material used is plastic film, paper, or paper laminated with plastic film.

However, receptors based on plastic film or paper laminated with plastic film are generally expensive and suffer from problems such as the plastic film shrinking due to heat during transfer, which tends to make the surface of the transferred image uneven. Ta.

In addition, paper-based receptors do not have the risk of thermal shrinkage, but the fiber diameter of the cellulose fibers that make up the paper
The unevenness of the paper fibers, which are relatively large at 10 to 20 μm, is reflected in the sublimable dye-receiving layer, resulting in defective ink transfer and roughened transferred images. When pressed in an attempt to eliminate these irregularities and impart smoothness, there was a problem in that the ink absorption ability decreased and the transferability deteriorated.

As a receptor that solves the above problems, for example, a pigment with a thickness of 30 μm or more and 100 μm or less and a coating amount of 30 g/m ² or more and 80 g/m ^{2 or} less is applied to the surface of a paper base material whose main component is wood pulp. Those that include a coating layer (Japanese Patent Laid-Open No. 183889, 1983), and those that are based on cellulose paper and whose transfer surface is coated with a thermoplastic polymer material (Japanese Patent Laid-Open No. 59-1989)
-165688), on the surface of a base material such as synthetic paper, there is a fixing layer made of a resin layer that has good fixing properties for sublimable dyes, and a transparent film that can be made into a film by making the sublimable dye permeate the surface of this fixing layer and heat press. A combination of membranes (JP-A-Sho)
63-256491), and one in which a recording layer made of a mixture of wax and a resin having a melting point higher than that of wax is provided on the surface of a substrate (Japanese Patent Application Laid-open No. 60-82393).

[Problems to be Solved by the Invention] However, the above-mentioned receptors are called thermoplastic polymer coating layers, fixing layers, recording layers, etc., without particularly improving the surface smoothness of the base material itself. Since a receptive layer is provided, if the base material is made of pulp paper and the receptive layer is thin, it is not possible to reliably prevent white spots and blurring of the transferred image due to the unevenness of the base material. It was hot.

The above receiver has a pigment coated on the surface of the base material of 30 g/m2 or ^more , so the transferred image has excellent sharpness, clarity, and uniformity, but the amount of coating is relatively large and the pigment is coated on pulp paper. Since the pigment layer remains on the surface of the substrate without being absorbed by the substrate, this pigment layer tends to crack or crease when the substrate is bent, resulting in a decrease in the quality of the transferred image formed. There were flaws.

The purpose of the present invention is to provide a high-quality image that has excellent heat resistance, does not shrink due to heat during transfer, does not cause unevenness on the surface of the transferred image, has high whiteness, and also has good ink transfer and no white spots or bleeding in the image. An object of the present invention is to provide a sublimation type thermal transfer recording receptor capable of forming a high-density, high-resolution image.

[Means for Solving the Problem] In order to achieve the above object, a sublimation type thermal transfer is provided in which an image is formed by subliming and transferring the sublimable dye from a transfer body provided with a transfer layer containing the sublimable dye by heating. In recording receptors, chemical pulp 70~
A resin paint is applied to the surface of pulp paper made of 100% by weight cellulose fibers with a fiber diameter of 0.5 to 9 μm at a coating amount of 10 g/m ² or more and less than 30 g/m ² and the roll temperature is 130.
A base material made by pressing at ~180℃ and a pressure of 100~150Kg/ ^cm2 , and the surface of this base material coated with the resin paint and pressed is coated with a sublimation dye-staining resin and the hardening of this resin. A receptor layer is formed by coating a solution containing a crosslinking agent or a crosslinking agent for this resin and a solvent.

This will be explained in detail below.

The base material of the present invention contains 70 to 100% by weight of chemical pulp.
The main component is pulp paper containing Since it is mainly composed of pulp paper, all coloring substances such as lignin, pitch, carbohydrate decomposition products, and substances that absorb ultraviolet rays are removed, resulting in extremely glossy and high whiteness. The cellulose fibers constituting this chemical pulp are selected from ultrafine fibers having a fiber diameter in the range of 0.5 to 9 μm. When the fiber diameter exceeds 9 μm, the drawbacks of conventional paper receptors become apparent. Further, in order to increase the ink absorbing power of this pulp paper and prevent white spots and blurring of images, a resin paint is applied to the surface of the pulp paper in a coating amount of 10 g/m ² or more and less than 30 g/m ² . The resin coating preferably contains synthetic resins such as acrylic acid resin and vinyl chloride resin, and synthetic waxes such as polyethylene wax and paraffin wax, particularly 0.5 to 80% by weight of acrylic acid resin and 0.05 to 50% by weight of acrylic acid resin. % of polyethylene wax is preferred. Coating amount is 10g/
If it is less than m ² , the ink absorption capacity of the pulp paper will not be sufficient, and if it is more than 30 g/m ² , cracking, folding, etc. will occur, so the coating is carried out within the above range.

Furthermore, in order to improve the smoothness of the pulp paper, it is pressed using a calender roll at a roll temperature of 130 to 180°C and a pressure of 100 to 150 kg/cm ² . roll temperature
If the temperature is less than 130℃ and the pressure is less than 100Kg/ ^cm2 , the pulp paper will not have sufficient smoothness, and the roll temperature will be 180℃.
If the temperature exceeds 150 kg/cm 2 and the pressure exceeds 150 kg/cm ² , unevenness will occur, so pressing is performed within the above range.

The pulp paper of the present invention has a thickness of 50 μm or more depending on the application.
Selected from a range of about 500 μm.

The sublimable dye-staining resin contained in the receptor layer provided on the surface of the base material is selected from a resin that has an affinity for sublimable dyes and a softening temperature of 125° C. or higher. Examples of synthetic resins include thermoplastic resins such as vinyl chloride resin, vinylidene chloride resin, fluorine resin,
Vinylidene fluoride resin, vinyl acetate resin, polystyrene resin, methacrylic acid resin, acrylic acid resin, polyethylene resin, ethylene vinyl acetate copolymer, polyamide resin, polyvinyl acetal resin, polycarbonate resin, saturated polyester resin, polyarylate resin, polysulfone resin etc. Examples of thermosetting resins include phenol resins, melamine resins, alkyd resins, unsaturated polyester resins, epoxy resins, and polyurethane resins. The above synthetic resins can be used alone or in combination of two or more.

The curing agent for the sublimation dye-staining resin or the crosslinking agent for this resin is selected from those compatible with the sublimation dye-staining resin, such as polyisocyanate, amino acids, epoxy resins, melamine resins, etc. For resins that are cured by electron beams or electron beams, ultraviolet absorbers and electron beam absorbers can also be used.

The above-mentioned receptor layer is provided by further coating on the resin coating surface of the pulp paper.

[Effects of the Invention] As described above, conventional receptors made of base materials mainly composed of plastic film have the problem of heat shrinkage during transfer, and the smoothness of the base material surface before forming the receptor layer has to be improved. If the receiving layer is made thicker to avoid this, cracks and creases tend to occur, and if the receiving layer is made thinner to avoid this, white spots and bleeding in the transferred image cannot be reliably prevented. Since the base material is mainly pulp paper, there is no heat shrinkage during transfer, and since the pulp paper is coated with resin paint and heat pressed, the amount of resin paint applied is 10g/m ² Even if the amount is relatively small (less than 30 g/m ^{2 )} , the sublimable dye on the transfer material can be transferred to the receiver at high concentration and resolution, reliably preventing the occurrence of white spots and blurring on the transferred image. It has many excellent effects, such as preventing the resin paint from cracking or creases even when bent.

[Example] Next, examples of the present invention will be described.

First, a high-quality pulp paper with a thickness of 130 μm made of 100% by weight chemical pulp made of cellulose fibers with a fiber diameter of 0.5 to 9 μm was selected, and the resin paint shown below was coated on the surface of this pulp paper at a coating amount of 20 g/ ^m2. I worked on it.

●Acrylic acid resin aqueous solution Primer WS-32
(Nippon Acrylic Chemical Co., Ltd.) 50mL ●Polyethylene wax aqueous dispersion Permarin
PN (Sanyo Chemical Co., Ltd.) 20mL ●Water 30m After coating the above resin paint, it was pressed with a calendar roll at a roll temperature of 150°C and a pressure of 120Kg/cm ² to obtain a base material.

Next, a receptive layer coating solution having the composition shown below was further applied onto the surface coated with the resin paint to provide a receptive layer of 10 g/m ² .

●Polyester resin UE-3210 (Unitika Co., Ltd.)
12.0g ●Crosslinking agent polyisocyanate Takenate D-
110N (Takeda Pharmaceutical Co., Ltd.) 0.6g ●Silicone surfactant KF-351 (Shin-Etsu Chemical Co., Ltd.) 0.5g ●Silicone white resin fine powder X-52-590 (Shin-Etsu Chemical Co., Ltd.) 0.5g ●Ultraviolet absorber Sanduvor EPU (Sand Co., Ltd.) 0.4g ●Toluene 50mL ●Methyl ethyl ketone 50mL Further, on one side of a 6 μm thick polyester film, apply a transfer layer ink having the composition shown below.
A transfer body provided with a transfer layer of 1 g/m ² was obtained.

●Sublimable disperse dye 5g ●Ethyl cellulose 8g ●Toluene 10mL After overlapping the obtained transfer body and receptor so that the transfer layer and receptor layer are in contact with each other, they are controlled by electrical signals according to image information. It was loaded onto the dot-like heat-sensitive means of a thermal head that generates heat. The transfer body was heated from the back side with a dotted heat-sensitive means of a thermal head to transfer the sublimable dye in the transfer layer into the receiving layer to form a natural color photographic image.

This transferred image had a whiteness of 95% GE or higher, did not curl, had no unevenness on the surface of the image due to heat shrinkage, and a high-density, high-resolution image was obtained. In addition, the above receptor was left in a high temperature room at 200℃ for 10 hours,
No thermal deformation occurred.

Claims (1)

[Scope of Claims] 1. A sublimation-type thermal transfer recording receptor in which an image is formed by subliming and transferring the sublimable dye from a transfer body provided with a transfer layer containing a sublimable dye by heating, comprising chemical pulp 70~ 10 g /
A base material made by applying a resin paint with a coating weight of ² m2 or more and less than 30 g/ ^m2 and pressing at a roll temperature of 130 to 180°C and a pressure of 100 to 150 Kg/ ^cm2 , and the above of this base material. Consisting of a receptor layer provided by applying a solution containing a sublimable dye-staining resin, a curing agent for this resin, or a crosslinking agent for this resin and a solvent to a surface coated with a resin paint and pressed. A dye-sublimation heat-sensitive transfer recording receptor characterized by: 2. The receptor for sublimation thermal transfer recording according to claim 1, wherein the resin coating contains 0.5 to 80% by weight of acrylic acid resin and 0.05 to 50% by weight of polyethylene wax.