JPH08332785A - Thermal stencil printing base sheet and manufacture thereof - Google Patents

Abstract

PURPOSE: To provide a thermal stencil printing base sheet capable of obtaining string stiffness and excellent image quality. CONSTITUTION: A wall-like film (in the case of, for example, a thermoplastic resin film as a floor, an aggregate of cells having many ceilings or an aggregate of honeycomb-like cells having no ceiling) is provided on one surface of a thermoplastic resin film. This wall-like film is used as a support for operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive stencil printing plate precursor and a method for producing the same, and more particularly to a structure of a support provided in contact with a thermoplastic resin film and a method for producing the same. is there.

[0002]

2. Description of the Related Art A porous thin paper as an ink permeable support (hereinafter sometimes simply referred to as "support") is attached to a thermoplastic resin film (hereinafter sometimes simply referred to as "film") with an adhesive. Further, a heat-sensitive stencil printing original plate in which a stick preventing layer for preventing sticking with a thermal head is provided on the film surface is known. In practice, a heat sensitive stencil printing plate is widely used in which a film is attached to a liner fiber or a mixture of linen fiber and synthetic fiber or wood fiber with an adhesive as a porous thin paper and an anti-stick layer is provided on the film surface. Has been.

However, in such a conventional heat-sensitive stencil printing plate, (1) a large amount of adhesive is accumulated in the form of a bird's web at the portion where the overlapping portion of the fiber and the film are in contact, and the portion is perforated by the thermal head. Is less likely to occur, and that part impedes the passage of ink, resulting in uneven printing. (2) The fibers themselves impede the passage of ink, resulting in uneven printing, and (3) expensive fibers. However, the loss due to the laminating process is large, the original plate for heat-sensitive stencil printing becomes expensive, and the problem of environmental protection due to fiber production and disposal cannot be overlooked.

[0004]

Considering these points, several heat-sensitive stencil printing plates have been proposed. For example, JP-A-3-193445 discloses a support using ultrafine fibers having a fineness of 1 denier or less. According to this, the problem of (1) above is solved, but (2) and (3)
The problem of is left. Japanese Patent Application Laid-Open No. 62-198459 discloses a method of forming a heat-resistant resin pattern having a substantially closed shape on a film by using a printing method such as gravure, offset, flexo, and the like. Discloses a heat-sensitive stencil printing plate precursor having a porous layer having a peak pore size of 0.06 to 10 μm as a support. However, when these are used, printing unevenness occurs.

However, Japanese Unexamined Patent Publication (Kokai) No. 54-33117 discloses a printing original plate which is substantially composed of a film without using a support, and according to this, the above (1) and (2) are disclosed.
Although the problem of (3) is solved, it also causes a new problem. One of them is the "stiffness" when the film is 10 μm or less in thickness.
The strength is small and it becomes difficult to carry. As a solution to this problem, in Japanese Examined Patent Publication No. 5-70595, the film is wound around the peripheral wall of the plate cylinder of a printing machine in a long shape without being cut, and the entire film rotates with the rotation of the plate cylinder during printing. Proposed. However, in this method, since the film and the loading / unloading plate unit rotate together with the rotation of the plate cylinder during printing, the rotation moment becomes large,
In addition, the displacement of the center of gravity from the rotation axis is large, and the printer must be heavy and large in order to solve these problems.
The other is that when the film has a thickness of 5 .mu.m or more, its thermal sensitivity becomes small and it becomes difficult to perform perforation by the thermal head. An object of the present invention is to provide a heat-sensitive stencil printing plate precursor and a method for producing the same, which solve these problems.

[0006]

Means for Solving the Problems As a result of studying the heat-sensitive stencil printing plate precursor from various angles,
(A) It is desirable that there is no support as much as possible that prevents the passage of ink and also prevents perforation by the thermal head, but this causes the film stiffness to be small and hinders its transportation. The strength of an object is proportional to the cube of its thickness. (C) While the support desirably has a relatively small contact point with the film,
From the consideration that the constituent elements are in contact with the film at an angle close to 90 degrees, it was confirmed that the heat-sensitive stencil printing plate precursor having a wall-like film on one surface was desirable. The present invention has been made thereby.

The term "wall-like film" as used herein means an aggregate of cells having a large number of ceilings (FIGS. 1 and 2) or an aggregate of honeycomb-like cells without a ceiling when the film is used as a floor on a film. It is meant to form the body (Fig. 3) and the like.

According to the present invention, (1) a heat-sensitive stencil printing plate precursor having a wall-like film on one surface of a thermoplastic resin film, (2) the wall-like film in (1) above (3) The above-mentioned (1) or (2), wherein at least a part of the wall-like film has a softening temperature of 150 ° C. or lower, wherein the heat-sensitive stencil printing plate is bonded to each other. (4) The above-mentioned (1), (2) or (3), wherein at least a part of the wall-shaped film is not film-like due to the influence of the printing ink. , Are provided.

Further, according to the present invention, the above (1) and (2)
(5) As a means for preparing the heat-sensitive stencil printing original plate of (4), (5) a wall-like film formed by foam is provided on a thermoplastic resin film. Production method, (6) A method for producing a heat-sensitive stencil printing original plate, which comprises applying a fluid composition having a foam residue onto a thermoplastic resin film and drying it, and (7) a substance for generating a foam residue. A method for producing a heat-sensitive stencil printing original plate, which comprises applying a fluid composition containing the composition onto a thermoplastic resin film and generating a gas during or after the application, (8) Generating gas by contacting each other To do 2
At least one of the above components is coated on a film, and a fluid composition containing the other component is applied to the coated surface to foam and form a film. (9) A heat-sensitive stencil printing original plate characterized by comprising: applying a fluid composition in which a gas is dissolved under an atmospheric pressure higher than 1 atm to a thermoplastic resin film under normal pressure and foaming the composition. A manufacturing method is provided.

The present invention will be described in more detail below. As described above, the "wall-shaped film" in the present invention is a film formed on a film by comparing a film to a floor to form an aggregate of cells with a large number of ceilings or an aggregate of honeycomb-like cells without a ceiling. However, the thickness (h ₁ in FIG. ₁ and h ₃ in FIG. ₃ ) of one wall-shaped film is generally 0.5 to 10 μm. Moreover, the size of one cell is 5 to 3000 μm in consideration of the passage of stencil ink after plate making and the strength of the body.
It is preferably 100 to 1000 μm.

The cell may be in a closed state or a part of it may be open. The opening can be achieved by, for example, breaking the foam film in the drying process. The broken line in FIG. 1 and the donut-shaped inner side in FIG. 2 represent openings. FIG. 3 shows a state in which all are open. The angle formed by the film and the wall-like coating near the thermoplastic resin film, that is, the rising angle θ of the wall-like coating from the film is preferably 20 degrees or more, more preferably 30 degrees or more, and the upper limit is It is 90 degrees. These wall-like coatings form cell aggregates and the like and serve as a support.

The wall-like coating is preferably softened at a temperature of 150 ° C. or lower in order to make the perforation of the film by the thermal head more effective.

Printing is performed by passing ink through the perforated portion of the film by the thermal head,
Ink cannot pass through when the cells are closed. However, the heat-sensitive stencil printing ink is generally a W / O emulsion, and this problem can be solved by the fact that the wall-like film is substantially destroyed by the plate-making with these components and becomes non-film-like. Therefore, it is desirable that the cell is not in the closed state.

For forming cells, it is possible to use a substance which exhibits the above-mentioned characteristics by being mixed even if it does not exhibit the above-mentioned characteristics by itself. Means for destroying a part of the coating by mechanical or chemical means may be used during or after formation.

In practice, in order to manufacture the heat-sensitive stencil printing plate precursor of the present invention, it is preferable to form a wall-like film formed by bubbles on the thermoplastic resin film.

The plastics as the main component of the wall coating material include polyethylene, polypropylene, polybutene, styrene resin, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetate, polyacrylonitrile, polyacrylic acid plastic, Diene plastics, polyamides, polyesters, polycarbonates, polyacetals, fluororesins, polyurethane plastics, various natural plastics, natural rubber plastics, various thermoplastic elastomers, cellulosic plastics, microbial plastics, copolymers containing these polymers, etc. Can be given. In addition, various fatty acids, various carbohydrates such as wax, and various proteins can also be used.

In order to form a wall-like film, a fluid composition containing foam, a fluid composition containing one of two or more components which generate gas when they come into contact with each other, or 1 A fluid composition in which a gas is dissolved at a pressure higher than the atmospheric pressure is used, and the following components and the like are added to this in addition to the above wall coating material.

Examples of the viscosity improver of the liquid (i) include CMC, polyvinyl alcohol, glycerin, chrycols, sodium alginate and the like. (Ii) As a form of existence, solvent-free system, solvent system (dissolution, dispersion), water system (dissolution, dispersion), emulsion system, etc. (Iii) Powders, pigments, fibrous substances, fluids with low volatility, etc. are included in order to improve the stability of the foam, facilitate the formation of a film, increase the strength, and change the characteristics. You can also As the powders and pigments, various organic and inorganic powders and pigments are used, and as the fibrous substances, animal and plant natural fibers, mineral fibers, glass fibers, metal fibers, synthetic fibers, silica fibers and the like are used. As the fluid having low volatility, fats and oils, oils, plasticizers, activators and the like are used. (Iv) As the surfactant for improving the foaming property,
Anionic, cationic, zwitterionic, and nonionic types are used. Among them, the anionic type is preferable in terms of foaming property. Particularly, higher alcohols such as higher alcohol sulfates are excellent in foaming property and foam stability. In the case of water system, the addition amount to water is 0.001 to 0.1% by weight.
Is. Egg white, saponin, gelatin, etc. also improve the foam stability.

The amount of adhesion of the wall-like film as a support is 0.5.
25 g / m ^2, especially 1 to 7 g / m ² or less. An increase in the adhered amount impedes the passage of ink and deteriorates the image quality.
If it is less than g / m ² , the effect of strengthening the body is small, and conversely,
When it is 25 g / m ² or more, the ink is prevented from passing and the image quality is deteriorated. The thickness of the coating as a support (the aggregate of cells becomes the coating as a support, not a single coating) (H ₁ ,
H ₃ ) is 200 μm or less, preferably 100 μm or less. If the thickness after coating is larger than the target thickness, it can be reduced to the target thickness by means such as pressure bonding with a calendar. The thickness is measured with virtually no load or with a very small load.

The following method is employed to form a wall-like film composed of bubbles. A substance such as a film-forming agent, a surfactant, and the like are added to a liquid such as water, and the mixture is stirred, foamed with an agitator, mixer, etc., applied, and dried. Besides foaming, a chemical reaction can be used as a foaming means. For example, it is applied and dried before bubbles such as a reaction between sodium hydrogen carbonate and an acid such as tartaric acid and a reaction between aluminum sulfate and sodium hydrogen carbonate disappear. The formulation of the coating liquid, stirring conditions, etc. are determined by some experiments. For coating, various types of coaters such as an air doctor, a blade, a truss roll, a rod, a reverse roll, a gravure, a die, a notch bar, and a fountain are used. As the drying conditions, it is necessary that the thermoplastic resin film is not adversely affected, and the drying temperature is preferably 60 ° C. or lower.

For example, wax or polyethylene glycol which exhibits fluidity at about 50 ° C. to 60 ° C. is foamed, and after coating, it is cooled and solidified.

A composition fluid containing a foaming agent that generates a gas such as nitrogen, carbon dioxide, water vapor, oxygen and hydrogen by energy is applied, and a gas is generated by energy such as heat, light, electromagnetic waves, radiation and electricity. , Solidify the foam part. In this case, foaming may be performed after forming the wall-shaped film.
The capsules contained in the fluid may be dissolved or shaken by the action of heat or other energy, and a gas may be generated by a chemical or physical action. You may utilize what the capsule expanded by heat etc. as a bubble. Carbon dioxide gas generated by vaporization of dry ice and nitrogen generated by shining light on the diazo compound can also be used.

It is also possible to process at least one of two or more kinds of components which generate gas upon contact with each other into a film, and apply a liquid containing the remaining components to generate the gas. For example, an aqueous solution containing sodium hydrogen carbonate and a small amount of a substance having a film forming function such as CMC, polyvinyl alcohol, gelatin, and sodium alginate is applied to the film, dried, and then, citric acid, aluminum sulfate, and a film forming material. A liquid containing the above is applied thereon to generate bubbles of carbon dioxide gas, and dried to form a target film.

A gas such as air is dissolved in the liquid under high pressure, and then the film is applied under normal pressure to generate bubbles and dried to form a target film.

In addition, in order for printing to be performed, the ink must pass through the support (wall-like film), but the wall-like film due to the bubble smear covers the film in a hemispherical shape so that the ink can pass through. If there are not enough holes,
Make holes for ink to pass through by rubbing the surface on which the film is formed. This work is performed, for example, on the winding section of the coating machine or on the slitter.

[0026]

EXAMPLES Next, the present invention will be specifically described with reference to Examples and Comparative Examples. Parts herein are by weight.

Examples 1 to 5 Biaxially stretched polyester having a thickness of 2 μm was used as a film. The liquids having the formulations shown in Table 1 were bubbled using a homomixer, and the bubbles were coated on the film using an air knife coater and dried at 50 ° C to 70 ° C (Examples 1 to 4). In Example 5, foaming foam was applied and dried without using a homomixer. The amount of adhesion after drying is ^{2 to} 7 g / m ²
Met. On the opposite side, a mixture of 80 parts of silicone resin and 20 parts of cationic antistatic agent was added to prevent sticking of the heat-melted film on the thermal head and for the purpose of antistatic, and the amount of adhesion after drying was about 0.05
The coating was performed so that it would be g / m ² . The strength of the body was measured by Lorenz Enstef Nestaster. The transportability and the image were tested with Tohoku Ricoh VT-1730 and its ink. The evaluation results are summarized in Table 2.

[0028]

[Table 1]

Comparative Example 1 Stretched by a factor of 1.5 or more in the longitudinal and transverse directions and has a thickness of 20 μm.
m or less thermoplastic resin film (JP-A-54-3311)
Stretched polyethylene, polypropylene, polyvinyl chloride, vinyl chloride-vinylidene chloride copolymer, polystyrene, polyester, nylon, etc., disclosed in No. 7) are used as the original plate for heat-sensitive stencil printing in the same manner as in Example 1. Plate-making printing was provided.

Comparative Example 2 A mixture of natural hemp (abaca) fibers and synthetic fibers was used as a support, and a stretched thermoplastic film having a thickness of 0.5 to 5 μm was attached to this support and used as an original plate for heat-sensitive stencil. ,
It was subjected to plate-making printing in the same manner as in Example 1.

Table 2 summarizes the evaluation results of the heat-sensitive stencil printing plate precursors of these Examples and Comparative Examples.

[0032]

[Table 2]

[0033]

According to the first, second, fifth, sixth, seventh, eighth and ninth aspects of the present invention, there can be obtained a heat-sensitive stencil printing plate precursor having a strong and high quality image. According to the inventions of claims 3 and 4, in addition to the above-mentioned effects, a heat-sensitive stencil printing plate precursor capable of effectively perforating with a thermal head can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an example of a heat-sensitive stencil printing original plate of the present invention.

FIG. 2 is a plan view of a support of another example of the heat-sensitive stencil printing original plate of the present invention.

FIG. 3 is a perspective view of another example of the heat-sensitive stencil printing original plate of the present invention.

[Explanation of symbols]

 1 film 2 bubbles

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Fumiaki Arai Inventor Fumiaki Arai 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. -1 Tohoku Ricoh Co., Ltd.

Claims (9)

[Claims] 1. A stencil printing plate precursor for heat-sensitive stencil printing, comprising a wall-shaped film on one surface of a thermoplastic resin film. 2. The heat-sensitive stencil printing original plate according to claim 1, wherein the wall-like films are bonded to each other. 3. At least a part of the wall-like coating is 150 ° C.
The heat-sensitive stencil printing original plate according to claim 1 or 2, which has the following softening temperature. 4. The heat-sensitive stencil printing plate precursor according to claim 1, wherein at least a part of the wall-shaped film is not film-shaped due to the influence of the printing ink. 5. A method for producing a heat-sensitive stencil printing plate precursor, which comprises forming a wall-like film formed by foaming on a thermoplastic resin film. 6. A method for producing a heat-sensitive stencil printing plate precursor, which comprises applying a fluid composition having a foam residue onto a thermoplastic resin film and drying the composition. 7. A method for producing a heat-sensitive stencil printing original plate, which comprises applying a fluid composition containing a substance capable of generating foam to a thermoplastic resin film and generating a gas during or after the application. Method. 8. A fluid composition containing one component of two or more components that generate gas when they come into contact with each other on a thermoplastic resin film, and the coated surface contains the other component. Is applied to form a heat-sensitive stencil printing plate. 9. A method for producing a heat-sensitive stencil printing original plate, which comprises applying a flowable composition in which a gas is dissolved under an atmospheric pressure higher than 1 atm to a thermoplastic resin film under normal pressure and foaming the composition.