JPS61177278A - Production of paper having excellent property for dry-type transfer color development of cationic dye - Google Patents

Abstract

PURPOSE:To enhance property for dry-type transfer color development of a cationic dye and light fastness, by providing a porous acrylonitrile polymer film comprising a particulate thermosetting resin on the surface of a film or paper. CONSTITUTION:A solution containing fine particles of a thermosetting resin and an acrylonitrile polymer containing acidic groups in an amount of not less than 0.1mol/kg-polymer is applied to the surface of a film or paper, and a wet-type coagulating treatment is conducted by use of a coagulating agent for the polymer, followed by washing with water and drying. Vinyl acetate, methyl acrylate, acrylamide or the like may be used as a comonomer for acrylonitrile, and the acidic groups in the polymer are preferably carboxyl groups or sulfonic acid groups. To provide a sufficient light fastness, it is necessary to use an acrylonitrile polymer containing not less than 30wt% of acrylonitrile.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing opaque paper having excellent cationic dye transfer color development properties for color hard copy.

[Conventional technology]

With the recent rapid spread of office automation, the use of color displays has rapidly increased in the core computers, word processing sensors, office computers, etc., and the demand for practical use of recording methods based on color signals is rapidly increasing.

Color recording methods include a thermal transfer method, an ink-end method, and a wire dot method, but the thermal transfer method is considered to be the most promising.

[Problem that the invention seeks to solve]

However, the current thermal transfer method is a dry transfer coloring technology using sublimable disperse dyes on synthetic fiber paper or synthetic resin film, and there are problems with the lack of dry transfer coloring properties and the clarity of hues caused by the disperse dyes. There is a strong need for improvement.

[Means to solve all problems]

The present invention involves coating the surface of a film or paper with a solution consisting of thermosetting resin fine particles and an acrylonitrile polymer containing at least 9 polymers per acidic group fl 1 mol/, and then using a coagulant for the polymer. Wet coagulation treatment is performed, followed by water washing and drying to form a porous acrylonitrile polymer film containing all thermosetting resin fine particles on the film or paper surface under high temperature, pressure and extremely short time conditions. This invention relates to a method for producing paper with excellent cationic dye dry transfer coloring properties.

[Effect]

The major feature of the opaque paper of the present invention, which has excellent cationic dye dry transfer coloring properties for color hard copies, is that it has excellent cationic dye dry transfer coloring properties and contains thermosetting resin fine particles on the surface of ordinary film or paper. It consists of a porous film laminated with an acrylonitrile polymer that exhibits light fastness.

In order to obtain a paper exhibiting excellent dry transfer coloring properties of cationic dyes, it is first necessary to use all of the water-insoluble acrylonitrile polymer containing at least 0.1 mol/kg of acidic groups. In this case, examples of the second component copolymerized with acrylonitrile include vinyl acetate, methyl acrylate, acrylamide, etc. The acidic group in the polymer is preferably a carboxyl group or a sulfonic acid group, and the enemy group is an acid type or It is necessary to be in the ammonium salt type.

The amount of acidic groups in the polymer is 0. If the total amount of acrylonitrile-based polymer is less than J mol/kg polymer, sufficient transfer coloring properties will not be imparted. Furthermore, sufficient light fastness cannot be imparted to the acrylonitrile-based polymer unless a polymer containing 30 ift% or more of acrylonitrile is used.

On the other hand, the action of thermosetting resin fine particles is that if they are appropriately contained in a porous acrylonitrile polymer film, they act as a buffer against external pressure during high-temperature transfer, and completely suppress deterioration of the porous acrylonitrile polymer film. , which enables dry transfer color development in an extremely short time.

In this case, the thermosetting resin fine particles used can be colorless or nearly colorless and have a particle size smaller than the thickness of the porous acrylonitrile polymer film, such as phenol resin, melamine resin, alkyd resin, etc. Fine particles of epoxy resin or the like are preferably used.

Another reason why these thermosetting resin fine particles are preferably used is that they have a small difference in specific gravity compared to the water-insoluble inorganic fine particles previously clarified by the present inventors, and they have a small difference in specific gravity from the IJ polymer. It has excellent uniform mixing properties.

On the other hand, the amount of thermosetting resin fine particles to be used varies depending on the type of thermosetting resin fine particles, but is usually preferably in the range of 0.2 to 2 parts by weight per 1 part by weight of the acrylonitrile polymer.

On the other hand, the film or paper used in the method of the present invention is not particularly limited to a film or paper to which the porous film of the acrylonitrile polymer described above can be firmly fixed. Plain paper is preferably used. The method of manufacturing the color hard copy paper of the present invention is to dissolve the above acrylonitrile polymer in a solvent, mix the thermosetting resin particles uniformly therein, coat the solution on a film or paper, and then apply a coagulating agent for the polymer. It is obtained by performing a rapid wet coagulation treatment using a solution, followed by washing with water and drying. As the solvent for the acrylonitrile polymer, common solvents for acrylonitrile polymers such as dimethylformamide, dimethylacetamide, dimethyl sulfoxide, etc. can be used. Further, the polymer concentration in the solution is preferably in the range of 10% to 25% by weight.

In addition, as a coating method, general coating methods such as knife coating and roller coating can be used.
Although the coating amount varies depending on the polymer concentration in the solution, a range of 60 μm to 30 μm is preferably used.

In the wet coagulation process, a method is used in which the polymer is immersed in a coagulant solution of an acrylonitrile polymer and rapidly coagulated. Water is preferably used industrially as the coagulating liquid for acrylonitrile polymers, and it is possible to perform coagulation treatment and solvent removal treatment at the same time.

After the wet coagulation treatment, it is thoroughly washed with water and dried at a temperature of 80°C or less. If drying is carried out at a temperature exceeding 80°C, the fine structure of the acrylonitrile polymer film will become denser, making it difficult for the dye to diffuse into the film during dry transfer of cationic dyes, and reducing the color development properties of dry transfer. let A porous acrylonitrile polymer film containing thermosetting resin fine particles is formed on the surface of the film or paper obtained by the above method, and the paper is processed by high temperature, pressure, and very short dry transfer using a heated roller, etc. Shows excellent dry transfer color development and light fastness of cationic dyes.

[Example J The present invention will be explained below with reference to Examples.

The dry transfer printing using cationic dye transfer paper and the measurement of transfer color development described in the text were carried out by the following method.

(1) Cationic dye dry transfer printing Using a thermal calendar roller, place cationic dye transfer paper (contains double cationic dye, blue color, made by Hodogaya Chemical Co., Ltd.) on the silkworm test film or paper, and apply a total pressure of 1 kg.
/cm"G' between thermal calendar rollers at a temperature of 200°C, and dry transfer printing is performed at a speed of 37)z/min.

(2) Measurement of Color Development After measuring Y (ilEffi) using Color Analyzer Model 307 (manufactured by Hitachi, Ltd.), the Y value was substituted into the Kuperka-Munk equation to calculate the /S value, which is shown as color development.

Example 1 Acrylonitrile polymer particles containing 91 parts by weight of acrylonitrile, 4% by weight of vinyl acetate, and 9 polymers per 015 mol of acidic groups were immersed in an aqueous solution containing three layers of ammonium chloride and treated at 98° C. for 30 minutes. After drying, acrylonitrile polymer particles converted to ammonium salt type acidic groups were obtained. This acryloni) I
A total coating solution was prepared by dissolving 2 parts by weight of J-type polymer particles and 5 parts by weight of melamine resin fine particles (average particle size 5 μm) in 10 parts by weight of an organic solvent dimethylformamide. This coating solution was coated to a thickness of 80μ and a basis weight of 65t/
After coating one side of commercially available cellulose woodfree paper with a thickness of 100μ using a knife coater, it was immersed in hot water at 70°C for 30 seconds to perform a rapid wet coagulation treatment.
It was washed with water and dried for 5 minutes using a hot air dryer at 60°C to obtain an opaque paper laminated with a porous acrylonitrile polymer film containing fine melamine resin particles. As a comparative example, an opaque paper laminated with a porous acrylonitrile polymer film was obtained in the same manner as above using a coating solution that did not contain melamine resin fine particles.

The dry transfer coloring properties of the above opaque paper using cationic dyes were measured and the following results were obtained.

The above results show that the paper of the present invention in which an acrylonitrile polymer film containing thermosetting melamine resin fine particles is formed on the cellulose woodfree paper of the present invention forms an acrylonitrile polymer film that does not contain melamine resin fine particles as shown in the comparative example. It can be seen that the dry transfer coloring properties using cationic dyes are more wearable than the paper made with cationic dyes.

Claims (1)

[Claims] After coating the surface of the film or paper with a solution consisting of thermosetting resin fine particles and an acrylonitrile thread polymer containing acidic groups of 0.1 mol/kg or more of the polymer, a wet coagulation treatment is performed using a coagulant for the polymer. , followed by washing with water and drying to form a porous acrylonitrile polymer film containing fine thermosetting resin particles on the surface of the film or paper.