JPH1180398A - Dishcloth gourd fibrous porous material, base paper for thermal stencil printing using dishcloth gourd fibrous porous material and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce the subject porous material, excellent in humidity curling characteristics due to an environmental fluctuation and useful as a base paper for thermal stencil printing by specifying a principal component and forming urethane bonds in a part thereof. SOLUTION: Urethane bonds are formed in a part of a dishcloth gourd fibrous porous material consisting essentially of (A) a polyvinyl acetal resin polymer and (B) a polystyrene acrylic acid copolymer. The objective porous material is preferably produced by dissolving the component A in a solvent, adding and mixing a solvent without dissolving the component A therewith, preparing a resin liquid A in a solubilized state, on the other hand, dissolving the component B in a solvent, adding and mixing a solvent without dissolving the component B therewith, preparing a resin liquid B in a solubilized state, undercoating the top surface of a support with an isocyanate compound, drying the coated isocyanate compound, then coating the top surface thereof with the resin liquid A, drying the coated resin liquid A, subsequently coating the dried surface with the resin liquid B and drying the coated resin liquid or coating the top surface of the support with a mixture liquid of the resin liquid A with the resin liquid B and drying the coated mixture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a specific fibrous porous body, a heat-sensitive stencil sheet using the fibrous porous body,
And their production methods.

[0002]

2. Description of the Related Art A heat-sensitive stencil sheet is composed of an ink-permeable porous support and a thermoplastic resin film perforated by heating. The thinner the thermoplastic resin film, the higher the sensitivity and image quality can be obtained at the time of perforation. However, it has been difficult to reduce the thickness to about 1 μm due to the manufacturing problem of thinning, but this problem has been overcome by the advancement of thin film technology (Japanese Patent Application Laid-Open No. 60-67196).
No., JP-A-62-176296). The physical properties of the thermoplastic resin film are also non-crystalline (Japanese Unexamined Patent Publication No.
No. 282983), having a melting point of 200 ° C. to 250 ° C. and a glass transition temperature of 70 ° C. or higher (Japanese Patent Laid-Open No. 2-307783).
No.) was invented.

[0003] For these reasons, it has become possible to obtain a thermoplastic film in which good perforations can be obtained. With the emergence of such excellent thermoplastic films, it is required that heat energy be transmitted to the thermoplastic film as evenly as possible in the stencil printing of heat-sensitive stencil printing. There is an increasing demand to be able to perforate the thermoplastic film well despite variations in thermal energy of the head.

As a solution, it has been proposed that fibers are arranged in one direction in a support made of natural fibers or synthetic fibers (Japanese Patent Publication No. 52640/1990). However, in this case, it is necessary to use an adhesive for adhesion between the support and the thermoplastic resin film, and the perforation sensitivity is reduced due to the influence of the adhesive, and the image density of printing is not sufficient. Since the surface of the body has a small roughness of 0.06 μm to 10 μm due to the silica contained therein, the heat insulation effect at the time of perforation is not sufficient, and further, only inks having low viscosity must be selected. Problems have been pointed out.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to increase the strength of a gourd fibrous porous membrane and to improve the curling characteristics of the porous membrane caused by atmospheric moisture (humidity). When used as a support layer, it has a heat insulating effect irrespective of the fluctuation of the thermal energy given by the thermal head, and at the time of printing, a liquid such as ink flows by averaging without deviating by a fixed amount at a time. Providing a porous body with high toughness and bending stiffness that can be transmitted without causing clogging, adheres to the thermoplastic resin film without using an adhesive for the thermoplastic resin film,
It is another object of the present invention to provide a heat-sensitive stencil sheet having excellent peeling strength, excellent printing durability, and excellent humidity curl characteristics caused by environmental changes.

[0006]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, have a polyvinyl acetal resin polymer and a polystyrene acrylic acid copolymer as main components, and a part thereof. It has been found that a gourd fibrous porous body having a urethane bond can achieve the above-mentioned object, and in particular, has excellent humidity curl characteristics due to environmental changes.
The present invention has been made based on this.

According to the present invention, first, the gourd fibrous porous body made of a synthetic resin is mainly composed of a polyvinyl acetal resin polymer and a polystyrene acrylic acid copolymer, and the gourd fibrous porous body is Is a gourd fibrous porous body characterized in that a part of it becomes a urethane bond.
Secondly, the pores formed as gourd fibers of the first gourd fibrous porous body have a diameter of 1 μm to 50 μm in terms of a perfect circle.
There is provided a gourd fibrous porous body characterized in the range of μm. Thirdly, there is provided a gourd fibrous porous body characterized in that the first and second gourd fibrous porous bodies contain a surfactant. Fourth, there is provided a gourd fibrous porous material, wherein the third surfactant contains a surfactant having an HLB value of 4 to 18.

Fifth, according to the present invention, a thermosensitive stencil characterized in that any one of the first to fourth layers of the gourd fibrous porous body is provided on one surface of a thermoplastic resin film. A printing base paper is provided. Sixth, the peel strength between the thermoplastic resin film and the gourd fibrous porous material layer is 1 to 5.
Stencil printing sheet is provided, characterized in that from 0 gf / cm ² in the range of 500 gf / cm ^2.

According to the present invention, seventhly, a polyvinyl acetal resin polymer is dissolved in a solvent, and a solvent that does not dissolve the polyvinyl acetal resin polymer is added to and mixed with the solvent to prepare a resin solution A in a solubilized state. On the other hand, a polystyrene acrylic acid copolymer is dissolved in a solvent, and a solvent that does not dissolve the polystyrene acrylic acid copolymer is added thereto and mixed to prepare a resin solution B in a solubilized state. There is provided a method for producing a gourd fibrous porous body, which comprises mixing an isocyanate compound with a resin liquid B, applying the mixture on a support, and drying the mixture.

Eighth, a polyvinyl acetal resin polymer is dissolved in a solvent, and a solvent that does not dissolve the polyvinyl acetal resin polymer is added to and mixed with the solvent to prepare a resin solution A in a solubilized state. The copolymer is dissolved in a solvent, and a solvent that does not dissolve the polystyrene-acrylic acid copolymer is added to and mixed with the solvent to prepare a resin solution B in a solubilized state. A gourd characterized by applying the resin liquid A thereon and drying it and then applying and drying the resin liquid B, or applying and drying a mixed liquid of the resin liquid A and the resin liquid B on a support. A method for producing a fibrous porous body is provided.

Ninth, a polyvinyl acetal resin polymer is dissolved in a solvent, and a solvent that does not dissolve the polyvinyl acetal resin polymer is added thereto and mixed to prepare a resin solution A in a solubilized state. The copolymer is dissolved in a solvent, and a solvent that does not dissolve the polystyrene-acrylic acid copolymer is added to and mixed with the solvent to prepare a resin solution B in a solubilized state. After B ′, the resin liquid A is applied and dried on the support and then the resin liquid B ′ is applied and dried, or the resin liquid B ′ is applied and dried on the support and then the resin liquid A is applied. A method for producing a gourd fibrous porous body characterized by coating and drying is provided.

Tenth, a polyvinyl acetal resin polymer is dissolved in a solvent, and a solvent that does not dissolve the polyvinyl acetal resin polymer is added to and mixed with the solvent to prepare a resin solution A in a solubilized state. An isocyanate compound is added to form a resin solution A '. On the other hand, a polystyrene acrylic acid copolymer is dissolved in a solvent, and a solvent that does not dissolve the polystyrene acrylic acid copolymer is added thereto and mixed. Is prepared, a resin solution A ′ is placed on a support.
Coating and drying, or applying and drying with a resin liquid B, or applying and drying the resin liquid B on a support, and then applying and drying the resin liquid A ', wherein the gourd fibrous porous material is characterized in that A method of making a body is provided.

Eleventh, there is provided a method for producing a gourd fibrous porous body, wherein a surfactant is mixed and dissolved in the seventh to tenth resin liquids A and A '.

Further, according to the present invention, there is provided a method for producing a heat-sensitive stencil printing base paper, wherein a thermoplastic resin film is used as the seventh to eleventh supports.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The shape of the gourd fibrous porous body of the present invention is characterized in that fibers found in a dried gourd are entangled. This porous body is not made by crossing vertical and horizontal fibers such as natural fibers and synthetic fibers into a fibrous form, but has a three-dimensional spread of branched fibers, and voids are formed inside the porous body. The shape of the void is a gourd-like shape and is not a perfect spherical shape (FIGS. 1 and 2). The size of the voids and the ratio of open holes in the gourd fibrous porous body can be appropriately adjusted by the manufacturing method. The aperture ratio is generally between 10% and 85%,
The thickness of the resin fiber is 2 μm to 10 μm. The aperture is present at a thickness of 10 μm to 50 μm with respect to the plane. The determination of the morphology of the porous film is made by measuring the thickness of the resin fiber, the shape of the voids, and the like based on an electron micrograph. The opening ratio is determined by image processing of the hole and the fiber with white and black (1, 0) signals. It is calculated and defined.

The gourd fibrous porous body of the present invention can be used as a separation membrane that allows gas or liquid to permeate. It has extremely high elasticity as a characteristic and can be used as a semipermeable membrane. Further, since it is milky white and has a clean feeling, and has a surface that reflects light appropriately, it can be used as a curtain or other interior. By providing a layer of this porous material on one surface of a thermoplastic film, it can be used as a heat-sensitive stencil printing base paper. When used as a heat-sensitive stencil sheet, the size of the voids in the porous body is an important factor.

When the voids of the porous body are observed on a plane, the pore diameters are distributed between 1 μm and 50 μm in terms of a perfect circle. When the pore diameter is less than 1 μm, the heat insulating effect of the porous body is suppressed, so that the perforation sensitivity of the thermoplastic resin film is remarkably impaired, and the ink permeability is undesirably reduced. In this case, since the ink permeability is not sufficient, if a low-viscosity ink is used, bleeding occurs in the printed image, or the ink oozes out from the side of the printing drum or the rear end of the stencil sheet wound around. Occurs. This hole diameter is 5
When the thickness is 0 μm or more, the passage of the ink becomes too easy, so that the excess ink adheres to the printing portion, and the printed image quality is hindered by elongation and thickening.

The gourd fibrous porous body of the present invention is produced by subjecting a synthetic resin composition having a specific component composition to a specific treatment. The synthetic resin having a specific component composition that forms the gourd fibrous porous body of the present invention is formed of a polystyrene acrylic acid copolymer and a polyvinyl acetal resin polymer. With respect to the gourd fibrous porous membrane of the polyvinyl acetal resin polymer of the present invention, the object of the present invention cannot be achieved by using the polyvinyl acetal resin polymer alone. In addition, with respect to the gourd fibrous porous membrane of the polystyrene acrylic acid copolymer of the present invention, the object of the present invention cannot be achieved by using a resin of the polystyrene acrylic acid resin alone. Therefore, the subject of the present invention is to coexist a gourd fiber porous membrane of a polystyrene acrylate copolymer having a moisture absorption rate and an extremely low moisture absorption rate which are extremely slow as compared with this porous membrane in a gourd fibrous porous membrane of a polyvinyl acetal resin polymer. Is achieved.

Therefore, in the present invention, a structure in which a porous film of a polystyrene acrylic acid copolymer and a porous film of a polyvinyl acetal resin polymer coexist, for example, a porous film of the polystyrene acrylic acid copolymer of the present invention is used in a base layer. Provided,
A configuration in which a porous film of a polyvinyl acetal resin polymer of the present invention is laminated thereon, or a configuration in which a porous film of a polyvinyl acetal resin is provided in a base layer, and a polystyrene acrylic acid copolymer porous film is laminated thereon. Or, add a gourd fibrous porous membrane liquid of polystyreneacrylic acid copolymer to a gourd fibrous porous membrane liquid of a polyvinyl acetal resin polymer, apply it to a predetermined thickness on a support, and dry it. And a porous membrane is formed. The porous membrane formed on the support is separated from the support as necessary.

The molecular weight of the polystyrene acrylic acid copolymer of the present invention is preferably from 3,000 to 15,000,
500 to 8000 is most preferred. Generally, the polystyrene acrylic acid copolymer contains carboxylic acid as a constituent unit and is represented by an acid value. The acid value of the polystyrene acrylic acid copolymer of the present invention is preferably from 250 to 50, and most preferably from 240 to 100. preferable. Outside this range, for example, if it exceeds 250, blocking occurs in the porous membrane, causing a problem. If it is less than 50, it becomes insoluble in a specific organic solvent and the porous membrane of the present invention is not formed.

On the other hand, the specific component composition that forms the gourd fibrous porous body of the polyvinyl acetal resin composition of the present invention comprises a polymer of polyvinyl acetal, polyvinyl alcohol and polyvinyl acetate, and has a polymer terminal group. Has a structure of polyvinyl acetal, polyvinyl alcohol and polyvinyl acetate. The overall structural formula is as follows.

[0022]

Embedded image (Wherein, R is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms,
X is a number from 70 to 85; Y is a number from 10 to 25;
It is a number from 10 to 10. )

A polyvinyl acetal having a specific ratio,
The polyvinyl alcohol and polyvinyl acetate compositions are represented by X, Y, Z (wt.) Representing the amount of each composition shown in the above structural formula.
%). X is 70-85, preferably 75-83, Y is 10-25, preferably 11-2.
2, Z is a value in the range of 0.5 to 10, preferably 0.5 to 7. It is effective when the ratio of X to Y is in a specific range. That is, when the ratio of X to Y is 7: 1, it can be dissolved in the solvent used, and when it is 5: 1 to 4: 1, it can be further dissolved in the solvent.

A resin having a softening point in the range of 70.degree. C. to 85.degree. C. gives good results, and a glass transition point of 50.degree. C. to 90.degree.
A range of gives good results. Further, the molecular weight (weight average) affects the size of the fibrous pores of the gourd-shaped porous membrane. If the composition ratio of polyvinyl acetal, polyvinyl alcohol and polyvinyl acetate is constant, it depends on the molecular weight, and if the molecular weight increases, the pore size between fibers becomes smaller. For the above reasons, the molecular weight is selected from the range of 30,000 to 300,000. If the molecular weight is less than 30,000, the pore size becomes too large, which is not suitable. When the molecular weight exceeds 300,000, it becomes insoluble. Table 1 shows a specific composition.

[0025]

[Table 1]

The urethane of the gourd fibrous porous membrane of the present invention, in which a part of the gourd fibrous porous membrane is composed of urethane bonds, can be urethanized with a generally used isocyanate compound. Specifically, aromatic isocyanates, for example, as toluylene diisocyanate, 2,4-toluylene diisocyanate, 2,6-toluylene diisocyanate,
Dimer of 2,4 toluylene diisocyanate, naphthylene-1,5-diisocyanate, o-toluylene diisocyanate, diphenylmethane diisocyanate, triphenylmethane triisocyanate, tris- (ρ-isocyanatophenyl) polymethylene, polyphenyl isocyanate, And aromatic polyisocyanates. As the aliphatic isocyanates, for example,
Hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, block polyisocyanate, and the like. These may be used in combination of two or more. It is also possible to use a commercially available polyisocyanate compound other than those described above.
2, D103, D103H, D104, D202, D2
04, D215, D217, D212M6, D110
N, D120N, D140N, D160N, D165N
CX, D170, D181N (all manufactured by Takeda Pharmaceutical Co., Ltd.), Coronate L (manufactured by Nippon Polyurethane Industry Co., Ltd.) and the like.

Next, these isocyanate compounds are mixed and dissolved or mixed and dispersed in the polyvinyl acetal resin composition, and this is applied. Here, there is no problem even if the highly reactive aromatic isocyanate compound is laminated as a separate layer after the undercoating. In this way, by mixing the isocyanate compound with the gourd fibrous porous membrane of the present invention, a part of the specific polyvinyl acetal resin composition of the present invention or a polyvinyl acetal is obtained using a dry heat source used for evaporating the solvent. The urethanation reaction proceeds with a part of the solution comprising the resin composition. The drying reaction temperature is preferably from room temperature to about 80 ° C. Above that, thermal shrinkage to the heat-sensitive stencil printing base paper occurs, causing a change in volume and causing trouble. The degree of progress of partial urethane formation of the gourd fibrous porous membrane of the present invention was measured by a commercially available infrared spectrophotometer using urethane bond absorption (-R-
O-CO-N-) νC = 0 from 1740 cm ⁻¹ to 169
Judgment is possible at a peak of 0 cm ^-1 . The urethane bond absorption is described in an identification method based on the spectrum of organic chemicals, 3rd edition author: Shun Araki, translated by Mashiko Ichiro, "Infrared Spectroscopy" published by Tokyo Kagaku Dojin.

The gourd fibrous porous body of the present invention and the heat-sensitive stencil sheet using the same are prepared in a state in which the resin is precipitated and dissolved in a plurality of solvents having different solubilities, that is, in a solubilized state. Optimum properties can be obtained by manufacturing. Specifically, the above-mentioned polystyrene acrylic acid copolymer is dissolved in a ketone solvent. Next, an organic solvent such as an alcohol is added, and the mixture is temporarily stopped at a resin concentration at which the solution becomes cloudy, and an inorganic and / or organic pigment is added and mixed with a ball mill disperser. On the other hand, the polyvinyl acetal resin polymer of the present invention is dissolved in a solvent. Next, a solvent that does not dissolve the polyvinyl acetal resin polymer is added to the solution composed of the polyvinyl acetal resin polymer, and mixed with a ball mill disperser. Through the above steps, a gourd fibrous porous membrane resin solution is obtained.

Next, among the above-mentioned isocyanate compounds (in some cases, dissolved in a solution of ethyl acetate, toluene, alcohol, etc.), those having mild reactivity include polyvinyl acetal resin solution and / or polystyrene acryl. It can be added to the acid copolymer resin solution and applied to the surface of the thermoplastic resin film used for the heat-sensitive stencil printing base paper. The effect of the present invention can also be expected by applying a highly reactive material to the surface of the thermoplastic resin film used for the heat-sensitive stencil printing paper in advance and then applying the above-mentioned resin liquid in a laminated manner.

The method for forming the gourd fibrous porous membrane of the present invention comprises:
A specific polyvinyl acetal resin polymer is mixed with a plurality of solvents having different solubilities to prepare a resin solution A in a solubilized (micelle-generated) state, and a specific polystyrene acrylic acid copolymer is mixed with a plurality of solvents having different solubilities. After mixing to prepare a resin solution B in a solubilized (micelle-generated) state, a mixture of the resin solution A and the resin solution B is applied on a support at a constant thickness, and then solid-liquid under a specific drying condition. Separation proceeds (gelation) to produce a gourd fibrous porous membrane. In this case, a method of applying and drying the resin liquid A and then applying and drying the resin liquid B, and a method of applying and drying the resin liquid B and then applying and drying the resin liquid A can be adopted. When only the gourd fibrous porous membrane of the present invention is required, it is easy to pre-coat a commercially available silicone oil, a fluorine compound, or the like on a film or sheet of 40 μm or more, and peel off the porous membrane generated in the above-described process. Can be obtained.

This will be described more specifically below. First, the solvent for dissolving the polystyrene-acrylic acid copolymer is one that can uniformly dissolve the resin composition and can be evaporated when a drying treatment is performed in a state of being applied to a thermoplastic resin film. is there. As these solvents, ketones, ethers, ketone esters, ketone alcohols, ketone ethers and the like can be used.
Examples of ketones include acetone, diethyl ketone, dipropyl ketone, diisobutyl ketone, amyl ketone, and acetonylacetone. Examples of ethers include ethyl ether, isopropyl ether, butyl ether, dititer carbitol, diethyl cellosolve and the like. Examples of ketone esters include ethyl acetoacetate and ethyl pyruvate. Ketone alcohols include isopropyl cellosolve, cavitol bricidol, cellosolve, benzyl cellosolve, butyl carbitol, butyl cellosolve, methyl carbitol, methyl cellosolve,
Triethylene glycol monoether ether and the like can be mentioned.

The polystyrene acrylic acid resin composition is dissolved in these solvents, and the concentration is 3 to 30% by weight.
Preferably, it is 5 to 20% by weight. Solvents that do not dissolve the resin composition in the polystyrene acrylic acid copolymer solution are alcohols, water, hydrocarbons, and chlorinated hydrocarbons. Examples of the hydrocarbon include n-hexane, cyclohexane, chloroform, and carbon tetrachloride.
The addition amount of this solvent is 10 to 40% by weight. Addition is
Stop immediately after cloudiness occurs. When a solvent that does not dissolve the polystyrene acrylate resin composition is added, the solution of the polystyrene acrylate resin composition becomes a solubilized state. After sufficiently stirring the solution, the isocyanate compound is mixed and stirred at a ratio of 0.1% to 1% with respect to the total weight, and applied to the surface of the thermoplastic resin film. This thickness is generally between 3 μm and 15 μm. This coating solution is heated and dried with hot air at 50 ° C to 80 ° C. Heating time is 3
It is about 0 to 120 seconds. The gourd fibrous porous film produced in the above steps becomes a layer with a thickness of about three times, and a porous film having a thickness of 10 μm to 50 μm can be obtained.
In addition, when the polyvinyl acetal porous film is already formed on the thermoplastic resin film, the coating liquid is applied on the porous film.

Next, the gourd fibrous porous membrane formed of the polyvinyl acetal resin polymer is laminated on the gourd fibrous porous membrane formed of the above-mentioned polystyrene acrylic acid copolymer.
First, the polyvinyl acetal resin polymer is dissolved under reflux, and the concentration is 3 to 30% by weight, preferably 5 to 20% by weight.
And Solvents that do not dissolve the polyacetal resin polymer added to the solution of the polyvinyl acetal resin polymer are water, hydrocarbons, and chlorinated hydrocarbons. Examples of the hydrocarbon include n-hexane, cyclohexane, chloroform, and carbon tetrachloride. The addition amount of this solvent is 10 to 40% by weight. The addition stops shortly after cloudiness occurs. When this solvent is added, the solution of the polyvinyl acetal resin polymer becomes a solubilized state. After sufficiently stirring the solution, the solution is applied on the surface of a thermoplastic resin film or on a polystyrene acrylate porous film. This thickness is generally between 3 μm and 15 μm. Apply this coating solution to 50
Heat and dry with hot air at a temperature of from 80C to 80C. The heating time is about 30 seconds to 120 seconds. The gourd fibrous porous membrane produced in the above steps becomes a layer with a thickness of about three times, and a porous membrane having an overall thickness of 20 μm to 70 μm can be obtained. In addition, an isocyanate compound can be added to the polyvinyl acetal resin liquid at a ratio of 0.1 to 1% by weight.

When the gourd fibrous porous membrane on the surface of the thermoplastic resin film thus formed was peeled off and the absorption of urethane bonds was measured with a commercially available infrared spectrophotometer, a strong absorption at 1720 cm ^-1 was observed. The peel strength of the resin film from the surface is measured by AUTOGROPHAGS- manufactured by Shimadzu Corporation.
500g from 10gf / cm ² by measuring at 50A
A heat-sensitive stencil sheet having a peel strength of f / cm ² can be obtained. In addition, inorganic pigments (talc, alumina, various clay components, silica), natural fibers, and the like may be added and dispersed in the above resin solution for the purpose of further enhancing the strength of the porous body.
In some cases, melamine or epoxidation can be performed with methylol urea or the like.

For the purpose of averaging the pore size of the gourd fibrous porous body of the present invention, a general surfactant can be used.
Particularly effective surfactants are those having an HLB of 4 to 20, and more preferably those having an HLB of 6 to 18. As the surfactant, any of anions, cations, and nonions can be applied without being affected by ionicity. The surfactant used in the present invention can be expected to exert its effect by being mixed and dissolved in the resin solution of the porous membrane, and has an effect on the dispersibility of the organic / inorganic pigment used for the purpose of increasing the physical strength of the porous membrane. Can be expected.

Since the surfactant is used to control the solubilized (micelle formation) state by mixing the above-mentioned specific polyvinyl acetate resin composition in a plurality of solvents having different solubilities, the gourd fiber of the present invention is used. Affects the pore size and air permeability of the porous membrane. Therefore, when the HLB exceeds the applicable range, the effect of averaging the hole diameter is lost, and the hole diameter becomes coarse. On the other hand, if the HLB is 4 or less, it is not preferable because it becomes insoluble in a mixed solvent that dissolves the resin solvent. More specifically, it is also related to the polarity of the solvent of the porous membrane resin liquid,
After dissolving in a solution in which a plurality of solvents having different solubilities with respect to a certain fixed amount of the resin composition are mixed, dissolving at a liquid temperature about 10 ° C. higher than room temperature, and then cooling to room temperature, the liquid becomes cloudy. At this time, the surfactant of the present invention is used in an amount of 0.01% to 0.1%.
It is added at a concentration of 1% by weight. Regarding the liquid properties of the porous resin liquid, the liquid stability (liquid separation state) is better than that of the porous resin liquid, and when the pore diameter of the porous body after application is observed, it is uniform. Since the porous body of the present invention is configured to be laminated with a gourd fibrous porous membrane, the physical properties of the membrane are excellent in gas permeability, high in elasticity, and there are applications as a porous body alone.

The surfactant used in the present invention includes:
Alkyl carboxylic acid type, higher alkyl sulfate type,
Alkyl sulfonic acid type, alkyl allyl sulfonic acid type,
Alkyl amide sulfonic acid type, alkyl phosphoric acid type, polyoxyalkyl fatty acid, polyethylene glycol type, polyethylene glycol ester type, polyoxyalkyl fatty acid ester type, alkylphenol ethylene oxide type, ethylene oxide adduct of higher alcohol, polyoxyalkyl phenyl ether type, Polyoxyethylene polybenzyl phenyl ether type, amino ether type, fatty acid alkanolamide type, pluronic type,
High molecular alkyl oxide block type, higher alkyl amine type, higher alkyl quaternary ammonia type and the like can be used, but other surfactants can also be used, and two or more types can be used in combination.

The materials constituting the thermoplastic film of the heat-sensitive stencil printing paper of the present invention include polyester, nylon, polyolefin, polystyrene, polyvinyl chloride, polyacrylate, and ethylene-vinyl alcohol. Polymers, polycarbonate copolymers and the like can be mentioned. Of these, polyester is most preferred. Polyester is a substantially amorphous polyester film. The acid component of the polyester is selected from phthalic acid, aliphatic dicarboxylic acid, or three types having a hydrocarbon group of the carboxylic acid. The alcohol component of the polyester is selected from alkylene glycols, aliphatic saturated cyclic glycols, and aromatic diols.

Specific examples of the polyester include terephthalic acid or a mixed diol containing 15 mol or less of isophthalic acid and / or terephthalic acid containing phthalic acid as an acid component and ethylene glycol and cyclohexanedimethanol as main components. This is a film made of polyester condensed as an alcohol component. Particularly, when the alcohol component composition is 60 to 80 mol% of ethylene glycol, 1,4-
This is a polyester film in which cyclohexanedimethanol is 40 to 20 mol%. Thermoplastic resin film is
It is manufactured by an extrusion method or a casting method using these materials.

The thickness of the thermoplastic resin film is from 1 μm to
It is 15 μm, preferably 1 μm to 4 μm. The thermoplastic resin film has a heat shrinkage stress at 100 ° C. of 75 to 5
50 g / mm ² preferably 300~550g / mm ^2, the crystallinity is a resin film of less than 5%.

In the base paper for heat-sensitive stencil printing of the present invention,
By providing a heat fusion preventing layer on the thermoplastic resin film, it is possible to prevent sticking of scum due to heat fusion of the film or adhesive to the thermal head. For example, surfactants, silicone-based release agents, lubricants and the like are suitable for the heat-sealing prevention layer for the above-mentioned purpose, and more generally, in a heat-sensitive stencil sheet wound in a roll, the porous layer is used. Preferably, a material capable of maintaining the releasability for a long period of time without transferring to a material is preferably used. It is also possible to add an antistatic agent to the heat-fusion preventing layer.
It is preferable to set it to 1.0 μm.

The present invention does not use thin paper such as Japanese paper, non-woven fabric, and manila hemp as a conventionally used ink-permeable base, so that no adhesive is required, and there are problems with perforation sensitivity and thermal curl. Disappears.

[0043]

EXAMPLES Next, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

Example 1 As a polystyrene acrylic acid copolymer resin, a commercially available product of Johnson Polymer Co., Ltd., Joncri 680 (weight average molecular weight: 4900, oxidation: 215, softening point: 127 ° C.) was used. Dissolve. This resin solution is heated to 40 ° C. The resin liquid reprecipitated is dissolved while stirring while dropping 15 g of methanol to 100 g of the resin liquid. The liquid at this time becomes slightly cloudy. Next, a commercially available Coronate L 3% by weight manufactured by Nippon Polyurethane Industry Co., Ltd. is added to the resin solution. This is applied to a commercially available PET film by selecting a doctor so as to have a thickness of 10 μm. Subsequently, the solvent is volatilized in a drying box at 60 ° C. On the other hand, the polyvinyl butyral resin described in the text (vinyl acetate component 2 wt%, poval component 21 wt%,
Resin A with a butyral component of 77 wt% and an average molecular weight of 30,000
Dissolve in ethanol at 20% solids concentration using
This resin liquid is kept at 40 ° C. Next, 50 g of this resin liquid
Then, while dropping 5 g of n-hexane, the precipitated resin liquid is stirred and dissolved. The liquid at this time becomes slightly cloudy. A doctor is selected to apply this solution to the above-mentioned porous membrane so as to have a thickness of 10 μm, and the solution is laminated and applied. This coating solution is dried by evaporating the solvent in a drying box at 60 ° C., and cooled to room temperature.
If the porous film is peeled off from the T film and wound up, the gourd fibrous porous body of the present invention can be obtained. During this operation, the drying atmosphere minimizes the incorporation of moisture. The gourd fibrous porous body was analyzed for urethane binding with an infrared spectrophotometer A-202 of JASCO Corporation. The measurement was performed by the KBr method.
At this time, as a result of simultaneously measuring the infrared spectroscopic characteristics of the gourd fibrous porous body without the addition of Coronate L of Nippon Polyurethane Industry Co., Ltd., urethane bonds were observed at 1720 cm ^-1 . FIG. 3 is an infrared spectral characteristic diagram of the PVB gourd fibrous porous material, and FIG. 4 is an infrared spectral characteristic diagram of a part of the PVB gourd fibrous porous material being urethanized.

Example 2 Polyvinyl acetal resin described in the text (vinyl acetate component 2 wt.
% Poval component 19wt%, Butyral component 79wt%
%, A 15% by weight solution of resin B in a mixed solvent of acetone 10%, toluene 5% and ethyl acetate 10% at a liquid temperature of 20 ° C. using resin B) having an average molecular weight of 70,000.
Next, a commercially available surfactant (Noniball 4 manufactured by Sanyo Chemical Co., Ltd.)
0, polyoxyethylene alkyl ether type) with stirring at a ratio of 0.1 wt% with respect to the resin solution concentration.
-Hexane was added dropwise at 5 wt% to the resin solution, and the precipitated resin solution was stirred and dissolved. Next, Johnson Polymer 680 (weight average molecular weight 4900, oxidation 2
15. Softening point: 127 ° C., polystyrene-acrylic acid copolymer resin), dissolved in acetone at a solid concentration of 20%. This resin solution is heated to 40 ° C. This resin liquid is stirred and mixed with the polyvinyl butyral resin liquid in an equivalent amount. Subsequently, the state of resin deposition of the resin liquid is observed while dropping ethanol. With an addition amount of 15 wt% to 10 wt%, the liquid becomes slightly turbid. This resin liquid is laminated on a pre-layer (anchor layer) described below. The pre-layer is a commercially available Coronate L3 wt% manufactured by Nippon Polyurethane Industry Co., Ltd.
Was dissolved in ethyl acetate. For commercial PET film,
It was prepared so as to have a dry weight of 0.30 g / m ² , and a Coronate L solution was applied and dried. In the application of the above-mentioned resin liquid, a doctor was selected so that the dry weight was 7.0 g / m ² , and the coating was performed in a laminated manner. The drying and peeling steps from the PET film were performed in the same manner as in Example 1. Through the above steps, the gourd fibrous porous body of the present invention was obtained. This gourd fibrous porous membrane was analyzed for urethane binding in the same manner as in Example 1, and as a result, 17
Urethane bonds were observed at 00 cm ^-1 .

The shapes of the gourd fibrous porous bodies of Examples 1 and 2 were measured with an electron microscope (SEM-S-2, manufactured by Hitachi, Ltd.).
400), and the pore size distribution of the porous body was measured by image processing. As a result, the gourd fibrous porous body of Example 1 was 3 μm to 5 μm.
A pore size distribution of 0 μm is provided for 80% of the whole. Example 2
In the gourd fibrous porous body, a distribution of pore diameters of 85% or more was observed in the range of 10 to 20 μm. In addition, these gourd fibrous porous bodies were manufactured using AUTOG manufactured by Shimadzu Corporation.
As a result of measuring the breaking strength by ROPH AGS-50A, it was 120 gf in Example 1 and 300 gf in Example 2.

Example 3 A 10% crystallinity of 1.0% was used as a thermoplastic resin film.
Heat shrinkage stress at 0 ° C. is 480 to 500 gf / mm
^{2. Using a} 2.0 μm-thick copolymerized polyester film showing a melting temperature of 180 ° C., apply the resin solution of the porous membrane of Example 1 so that the dry adhesion amount becomes 7 g / m ² , and apply the coating at 60 ° C. for 1 minute After drying, a base film for heat-sensitive stencil printing of a porous film was prepared. As a result of observing the porous state of the prepared heat-sensitive stencil sheet with a SEM (S-2400) manufactured by Hitachi, Ltd., it was found that the fiber gap holes in the thermoplastic resin film were 5 to 30 μm in terms of a perfect circle.
It was confirmed that a heat-sensitive stencil sheet having a gourd fibrous porous membrane having a thickness of m was obtained.

Example 4 Using the thermoplastic resin film used in Example 3, a resin solution 1 having the following composition was stirred in a warm water atmosphere at 40 ° C. for 30 minutes to confirm dissolution, and then a dry adhesion amount of 8.5 g / m 2 was obtained. ^The mixture was applied with a doctor so as to obtain a composition of No. 2, and dried in an atmosphere at 60 ° C. for 1 minute to form a gourd fibrous porous film of a polystyrene acryl copolymer resin. (Resin solution 1) Polystyrene acrylic acid copolymer resin solution (manufactured by Johnson Polymer, JONCRYL 586, oxidation 108, MW 4600) 20% by weight Methyl ethyl ketone 60% by weight Methanol 19% by weight Next, a resin solution having the following composition (Table 1) Resin B) to 4
The mixture was stirred for 30 minutes in a warm water atmosphere of 0 ° C., and after confirming dissolution, was laminated and coated on the porous film of the polystyrene acrylic copolymer with a doctor so that the dry adhesion amount was 8.5 g / m ² . Dried under an atmosphere of 60 ° C. for 3 minutes to form a gourd fibrous porous body of a polyvinyl acetal resin polymer,
A heat-sensitive stencil sheet of the present invention was prepared. (Resin solution B) Polyvinyl acetal resin solution B (produced by Sekisui Chemical Co., Ltd., X79% by weight, Y19% by weight, Z2% by weight, MW7 × 10 ⁴ ) 20% by weight Ethanol 60% by weight n-hexane 19% by weight 2, 4-Toluylene diisocyanate (manufactured by Aldrich) 1.0% by weight The prepared stencil sheet for heat-sensitive stencils was observed with an electron microscope (SEM-S-2400) manufactured by Hitachi, Ltd. in the same manner as in Example 3. It was recognized that a heat-sensitive stencil sheet having a form in which a gourd fibrous porous body having a fibrous hole diameter of 15 μm in terms of a perfect circle supported a thermoplastic resin film on a resin film was obtained. This gourd fibrous porous membrane was prepared in Example 1.
Similarly, as a result of analyzing urethane binding, 1720
Urethane bonds were observed at cm ^-1 .

Example 5 Using the thermoplastic resin film used in Example 4, a resin solution 2 having the following composition was stirred in a warm water atmosphere at 40 ° C. for 30 minutes, and after confirming dissolution, 8.5 g of dry adhesion was observed. / M ^2, and dried in an atmosphere at 60 ° C. for 1 minute to form a gourd fibrous porous body of a polystyrene acrylic copolymer resin. (Resin solution 2) Polystyrene acrylic copolymer resin liquid (manufactured by Johnson Polymer Co., JONCRYL 683, oxidation 160, MW 8000) 20% by weight Methyl ethyl ketone 60% by weight Methanol 19% by weight Next, a resin solution having the following composition (Table 1) Resin C) to 4
After stirring for 30 minutes in a warm water atmosphere at 0 ° C., and confirming dissolution, on the porous material of the polystyrene acrylic copolymer resin,
The layer is coated with a doctor so that the dry adhesion amount becomes 8.5 g / m ^2, and dried under an atmosphere of 60 ° C. for 3 minutes to form a gourd fibrous porous body of a polyvinyl acetal resin polymer. A heat sensitive stencil sheet was prepared. (Resin solution C) Polyvinyl acetal resin solution (prototype manufactured by Sekisui Chemical Co., Ltd., (X79 wt%, Y19 wt%, Z2 wt%, MW9 × 10 ⁴ 20 wt%, ethanol 60 wt%, methyl ethyl ketone 19 wt%, 2,4-toluy) Range isocyanate (manufactured by Aldrich) 1.0% by weight Nonipol 60 (HLB10.6) (manufactured by Sanyo Chemical) 0.1% by weight The prepared heat-sensitive stencil sheet was subjected to an electron microscope manufactured by Hitachi, Ltd. in the same manner as in Example 4. As a result of observation by (SEM-S-2400), the number of pores between fibers was 2 in terms of a perfect circle on the thermoplastic film.
It was recognized that a heat-sensitive stencil sheet in a form in which a 5 μm gourd fibrous porous body supported a thermoplastic film was obtained. This gourd fibrous porous membrane was analyzed for urethane bonds in the same manner as in Example 1, and as a result, urethane bonds were observed at 1720 cm ^-1 .

Example 6 Using the thermoplastic resin film used in Example 4, a resin solution 3 having the following composition was stirred in a warm water atmosphere at 40 ° C. for 30 minutes, and after confirming dissolution, 8.5 g of dry adhesion was observed. / M ^2, and dried in an atmosphere of 60 ° C. for 1 minute to form a gourd fibrous porous body of a polystyreneacrylic acid copolymer resin. (Resin solution 3) Polystyrene acrylic acid copolymer resin liquid (manufactured by Johnson Polymer, JONCRYL 678, oxidation 215, MW 8500) 20% by weight Methyl ethyl ketone 50% by weight Methanol 19% by weight Ethanol 10% by weight Next, a resin having the following composition Add the solution (resin D in Table 1) to 4
The mixture was stirred in a warm water atmosphere of 0 ° C. for 30 minutes, and after confirming dissolution, the mixture was coated on the porous material of the polystyrene acrylic acid copolymer resin with a doctor so that the dry adhesion amount was 8.5 g / m ^2. And dried under an atmosphere of 60 ° C. for 3 minutes to form a gourd fibrous porous body of a polyvinyl acetal resin polymer to prepare a heat-sensitive stencil printing base paper. (Resin solution D) Polyvinyl acetal resin liquid C (produced by Sekisui Chemical Co., Ltd., X79% by weight, Y19% by weight, Z2% by weight, MW7 × 10 ⁴ ) 20% by weight Ethanol 60% by weight Methyl ethyl ketone 19% by weight 2,4- Toluylene diisocyanate (manufactured by Aldrich) 1.0% by weight Sorbon S-60 (HLB4.7) (manufactured by Toho Chemical Co., Ltd.) 0.1% by weight As a result of observation with an electron microscope (SEM-S-2400), the inter-fiber pores on the thermoplastic film were 2 in terms of a perfect circle.
It was recognized that a heat-sensitive stencil sheet in a form in which a 5 μm gourd fibrous porous body supported a thermoplastic film was obtained. This gourd fibrous porous membrane was prepared in the same manner as in Example 1,
As a result of urethane bond analysis, urethane bond was observed at 1720 cm ^-1 .

Comparative Example 1 Commercially available polyvinyl butyral 3000-1 (a resin having an average molecular weight of 60,000, manufactured by Denki Kagaku Kogyo Co., Ltd.) was dissolved in ethanol to a solid concentration of 20%. 5 g of water was added dropwise to 40 g of this solution with stirring, and dissolved while heating to 40 ° C. as in Example 1. As a result, the solution became cloudy. This resin liquid was applied to a commercially available PET film by selecting a doctor so as to have a thickness of 10 μm. Subsequently, the solvent was volatilized in a drying box at about 60 ° C. for one minute, and peeled off from the PET film. In this case, mixing of moisture in a dry atmosphere was prevented as much as possible. The porous body obtained by the above-described processing was evaluated for the breaking strength of the porous membrane in the same manner as in Example 1 by using AUTO, manufactured by Shimadzu Corporation.
As a result of measuring with GROPH AGS-50A, 3.0 g
f. Next, an electron microscope SEM- manufactured by Hitachi, Ltd.
As a result of observing the pore size distribution in S-2400, a gourd fibrous porous membrane similar to that of Example 1 was obtained.

Comparative Example 2 Commercially available VYHH (vinyl chloride 8 manufactured by Union Carbide Co., Ltd.)
3% by weight, 17% by weight of vinyl acetate, and a resin having an average molecular weight of 40,000) were dissolved in acetone to a solid concentration of 20%. To 25 g of this solution, 5 g of ethanol was added dropwise while stirring, and dissolved while heating to 40 ° C. as in Example 1. As a result, the solution became cloudy. This resin solution is commercially available P
A doctor was selected and applied to the ET film so as to have a thickness of 20 μm. Subsequently, the solvent was volatilized in a drying box at about 60 ° C. and peeled off from the PET film. in this case,
Mixing of moisture into the dry atmosphere was prevented as much as possible. A porous body was obtained by the above processing. However, as a result of observing this with an electron microscope SEMS-2400 manufactured by Hitachi, Ltd., it was found that the shape was a circular porous body of 80 μm to 50 μm generated by bubbles in a resin planar shape (FIG. 5).

Comparative Example 3 As a thermoplastic resin film, 100% crystallinity was 10%.
A 3.5 μm thick copolyester film having a heat shrinkage stress at 150 ° C. of 150 to 300 g / mm ² and a melting temperature of 180 ° C. was used. Instead of the resin solution 1 in the production method of Example 4, it was applied using the resin I of Table 1 and treated in the same manner to prepare a heat-sensitive stencil sheet. As a result of observing this sample with an electron microscope (SEM-S-2400 manufactured by Hitachi, Ltd.), the fibrous porous body of the present invention was not observed on the thermoplastic resin film.

Comparative Example 4 The resin solution B of Example 4 was separated twice, and the coating and drying were repeated. A laminated film was formed on a thermoplastic resin film in the same manner as in Example 4 to obtain a heat-sensitive stencil sheet. Created. This sample was taken with an electron microscope (SEM-S-, manufactured by Hitachi, Ltd.).
2400), a porous film was formed on the thermoplastic resin film, but the fibrous porous film of the present invention was not observed.

Comparative Example 5 A heat-sensitive stencil sheet was prepared in the same manner as in Example 1, except that the following resin solution E was used in place of the resin solution A in the method for preparing a heat-sensitive stencil sheet. (Resin solution E) Vinyl acetate polymer (Daicel Chemical: Sebian A-700) 20 parts by weight Ethanol 40 parts by weight 20 parts by weight isopropyl alcohol 20 parts by weight Toluene 20 parts by weight An electron microscope (Hitachi) As a result of observation with SEM-S-2400 manufactured by Seisakusho Co., Ltd., the pore shape different from the gourd-like fibrous porous film intended for the present invention was irregular on the thermoplastic resin film, and the pore density was low. A resin film was observed.

Comparative Example 6 The same procedure was followed as in Example 1 except that the following resin solution F was used in place of the resin A, except that the following resin solution F was used instead of the resin A. (Resin solution F) Vinyl chloride-vinyl acetate copolymer (manufactured by Union Carbide Co .: VYHH) 19 parts by weight Ethanol 40 parts by weight Isopropyl alcohol 20 parts by weight Toluene 20 parts by weight Coronate L (manufactured by Nippon Polyurethane Industry) 1.0 As a result of observing the porous pattern of the prepared heat-sensitive stencil sheet with an electron microscope (SEM-S-2400, manufactured by Hitachi, Ltd.), a circular hole was formed on the thermoplastic resin film, and the hole pattern was the same as in Comparative Example 1. A resin film having a low density was observed.

The overcoat solution consisting of a mixture of silicone and a cationic surfactant was added to the heat-sensitive stencil base paper of Examples 3 to 6 and Comparative Examples 3 to 6 in a dry adhesion amount of 0.1%.
It was prepared so as to have a concentration of 1 to 0.05 g / m ² , and was applied and dried. Using the heat-sensitive stencil sheet obtained as described above,
Table 2 shows the test results obtained by the following method.

(1) Perforation Sensitivity (Substitution Characteristic for Evaluating White Holes) For a given heat-sensitive stencil sheet, using a line-type thermal head in the plate-making section of Ricoh's Preport VT-3500, the applied energy was adjusted. Pierced underneath,
The optical density of the solid black portion (stable portion printed and printed in the standard condition in the character mode) is measured by a densitometer RD-914 manufactured by Macbeth Co., and the value when the standard black sample is blank is defined as the perforation sensitivity. When the value is 1.11 or more, ◎, 1.00 or more, 、, 0.99 to 0.88, Δ;
88 or less was evaluated as x. (2) Image distortion rate Using a line-type thermal head of the plate making part of Ricoh's Preport VT-3500, piercing was performed under the applied energy prepared, and the initial print image and the 3,000 print images were examined with an optical microscope. The elongation and fatness of the shape were evaluated, and the change rate of the predetermined shape was displayed as a percentage. (3) Flexural rigidity A heat-sensitive stencil sheet is made to a predetermined size, and a commercially available flexural rigidity meter (LORENTZEN WETRE STIFF) is used.
ESS TESTER). (4) Curl Characteristics The heat-sensitive stencil sheet was made to have a predetermined size, and the curl characteristics from a low humidity to a high humidity environment were measured by a change amount. (5) Peel strength The heat-sensitive stencil sheet was made to have a predetermined size, and the adhesiveness between the gourd fibrous porous body and the thermoplastic resin film was measured using Shimadzu Corporation (AUTOGROPH AGS-50A).

[0059]

[Table 2]

Comparing the evaluation results of the examples with those of the comparative examples in Table 2, the curl characteristics, perforation sensitivity and image density, bending stiffness, and peel strength of the comparative examples are clearly inferior to those of the examples. . In Examples 5 and 6, the effect of the surfactant was observed, and the inter-fiber pores were uniformed.
It can be seen that the ink passed well and the effect on print density and white spots was clear. In the peel strength and bending stiffness characteristics of the heat-sensitive stencil base paper, the example has a large effect,
A 10-fold increase in the peel strength of the heat-sensitive stencil base paper, or a 10 mmN increase in the bending stiffness appears. Next, the image distortion caused by stretching and tearing of the stencil sheet with printing resistance was also improved to 0.01% due to the increase in the physical strength of the gourd fibrous porous body. All of the above proved to be excellent.

[0061]

According to the present invention, the porous gourd fibrous body of the present invention comprises a polyvinyl acetal resin polymer and a polystyrene acrylic acid copolymer as main components, and a part of the gourd fibrous porous body is formed by a urethane bond. Is attached to one side of the thermoplastic resin film to provide a heat-sensitive stencil printing plate excellent in curl characteristics that are resistant to humidity changes in the environment, and with a porous film that is strong and print-resistant and stretches. In addition, by including a surfactant having an HLB of 4 to 18 in the gourd fibrous porous body, the pore size of the porous body is equalized, and the heat-sensitive stencil sheet having excellent image quality and high cost advantage is obtained. can get.

[Brief description of the drawings]

FIG. 1 is a view of the gourd fibrous porous body of the present invention observed with an electron microscope.

FIG. 2 is a view of the gourd fibrous porous body of the present invention observed with an electron microscope.

FIG. 3 is a diagram showing infrared spectral characteristics of a PVB gourd fibrous porous body.

FIG. 4 is a diagram showing infrared spectroscopic characteristics of PVB gourd fibrous porous material partially urethanized.

FIG. 5 is a view of a porous body in which air bubbles are generated on a resin plane in a conventional example, observed with an electron microscope.

Claims (12)

[Claims] 1. A gourd fibrous porous body made of a synthetic resin is mainly composed of a polyvinyl acetal resin polymer and a polystyrene acrylic acid copolymer, and a part of the gourd fibrous porous body becomes a urethane bond. A gourd fibrous porous body, characterized in that: 2. The pores formed as gourd fibers of the gourd fibrous porous body according to claim 1 have a diameter of 1 μm in terms of a perfect circle.
A gourd fibrous porous body having a range of m to 50 μm. 3. A gourd fibrous porous body characterized in that the gourd fibrous porous body according to any one of claims 1 and 2 contains a surfactant. 4. The gourd fibrous porous body, wherein the surfactant according to claim 3 contains a surfactant having an HLB value of 4 to 18. 5. A stencil sheet for heat-sensitive stencil printing, characterized in that a layer of the gourd fibrous porous body according to any one of claims 1 to 4 is provided on one surface of a thermoplastic resin film. 6. The peel strength between the thermoplastic resin film according to claim 5 and a gourd fibrous porous material layer is 10 gf / cm.
^A printing stencil for heat-sensitive stencils, characterized in that the thickness is in the range of ² to 500 gf / cm ² . 7. A polyvinyl acetal resin polymer is dissolved in a solvent, and a solvent that does not dissolve the polyvinyl acetal resin polymer is added to and mixed with the solvent to prepare a resin solution A in a solubilized state. The union is dissolved in a solvent, and a solvent that does not dissolve the polystyrene-acrylic acid copolymer is added thereto and mixed to prepare a resin solution B in a solubilized state. Then, an isocyanate compound is mixed with the resin solution A and the resin solution B. A method for producing a gourd fibrous porous body, wherein the porous body is coated on a support and dried. 8. A polyvinyl acetal resin polymer is dissolved in a solvent, and a solvent that does not dissolve the polyvinyl acetal resin polymer is added to and mixed with the solvent to prepare a resin solution A in a solubilized state. The union is dissolved in a solvent, and a solvent that does not dissolve the polystyrene-acrylic acid copolymer is added to and mixed with the solvent to prepare a resin solution B in a solubilized state.
After drying, the resin liquid A is applied and dried, and then the resin liquid B is applied and dried, or a mixed liquid of the resin liquid A and the resin liquid B is applied and dried on a support. A method for producing a gourd fibrous porous body. 9. A polyvinyl acetal resin polymer is dissolved in a solvent, and a solvent that does not dissolve the polyvinyl acetal resin polymer is added to and mixed with the solvent to prepare a resin solution A in a solubilized state. The union is dissolved in a solvent, and a solvent that does not dissolve the polystyrene-acrylic acid copolymer is added to and mixed with the solvent to prepare a resin solution B in a solubilized state. And then apply and dry the resin liquid A on the support and then apply and dry the resin liquid B ', or apply the resin liquid B' on the support and dry and apply the resin liquid A. A method for producing a gourd fibrous porous body, characterized by drying. 10. A polyvinyl acetal resin polymer is dissolved in a solvent, and a solvent that does not dissolve the polyvinyl acetal resin polymer is added to and mixed with the solvent to prepare a resin solution A in a solubilized state. To prepare a resin solution A ′, while dissolving the polystyrene acrylic acid copolymer in a solvent, and adding a solvent that does not dissolve the polystyrene acrylic acid copolymer thereto to prepare a resin solution B in a solubilized state. And then apply and dry the resin liquid A 'on the support and then apply and dry the resin liquid B, or apply and dry the resin liquid B on the support and then apply the resin liquid A'
A method for producing a gourd fibrous porous body, characterized by coating and drying. 11. A method for producing a gourd fibrous porous body, wherein a surfactant is mixed and dissolved in any one of the resin liquid A and the resin liquid A 'according to claim 7. 12. A method for producing a heat-sensitive stencil printing base paper, comprising using a thermoplastic resin film as the support according to any one of claims 7 to 11.