JPH0647317B2 - Method for producing heat-sensitive stencil plate - Google Patents

Description

The present invention relates to a method for producing a heat-sensitive stencil original plate,
More specifically, the present invention relates to a method for producing a heat-sensitive stencil original plate capable of obtaining a high-quality printed matter by a simple stencil printing method.

(Prior Art) A heat-sensitive stencil plate having a basic structure in which a thermoplastic film and an ink-permeable support are bonded together with an adhesive is known.
The ink-permeable support (hereinafter referred to as "support") used in these conventional master plates is, for example, Japanese Patent Publication No. 59-
As shown in Japanese Laid-Open Patent Publication No. 23719, Mitsumata, natural fibers such as kohzo, Manila hemp pulp, or synthetic fibers such as rayon, vinylon, tetron, and acrylic, or a mixture thereof (hereinafter referred to as “Washi”)
Or a mesh-like sheet as disclosed in JP-A-59-22796.

Further, for example, Japanese Patent Laid-Open No. 87095/1985 proposes a heat-sensitive copy base paper in which a large number of fibers are bonded to one surface of a film so as to be substantially parallel to each other at a predetermined interval and arranged in only one direction. Therefore, it has been proposed to use a large number of fibers, which are substantially parallel to each other and are spaced a predetermined distance, as a substitute for a support of Japanese paper or a mesh sheet.

Further, Japanese Patent Publication No. 49-5934 discloses that "a thermosensitive film having a heat-resistant resin layer having a closed pattern on a thermoplastic film, which does not substantially soften or melt at the temperature at which the film is perforated. A "printed copy base paper" has been proposed. In this case, the so-called support becomes a heat-resistant resin layer having a substantially closed pattern.

(Problems to be Solved by the Invention) However, the conventionally proposed heat-sensitive stencil plate is a heat-sensitive stencil plate in which a thermoplastic film (hereinafter referred to as “film”) and Japanese paper are attached with an adhesive, although there is a problem in print quality. It is actually used widely. That is, first, the most widely used one is a heat-sensitive stencil plate having a release layer on the film, which is adhered to the film and Japanese paper with an adhesive, and the infrared absorbing original and the film surface of the heat-sensitive stencil plate are pressed and brought into close contact with each other. A heat-sensitive stencil original plate which forms a perforated image corresponding to an original image pattern on the film by melting or shrinking the film by heat generated in the image portion of the infrared absorbing original by irradiating infrared rays from the Japanese paper side in this state As described in JP-A-60-87095, the thickness of the fibers of the Japanese paper, the size and shape of the openings of the Japanese paper are non-uniform, and the portion where the fibers overlap in the thickness direction is irregular. (A) The washi paper, that is, the support itself has a different flow resistance of the ink at each part, and the print image density differs due to the effect of the support itself at each part.

(B) When a perforated image corresponding to a document image pattern is formed by infrared irradiation, the fibers of the washi itself absorb a certain amount of infrared light, so the amount of infrared light that reaches the original image differs depending on each part due to the above characteristics. Perforation varies depending on the site.

(C) For example, JP-A-55-103957 and JP-A-60-97
There is also known a method in which a thermal element such as a thermal head is pressed against a heat-sensitive stencil original plate as illustrated in Japanese Patent No. 891 to punch a desired image. Even in this case, even if a certain amount of heat is generated in the heating element, the Japanese paper existing between the film and the platen roll has the above-mentioned characteristics, and the portion where the fibers are dense has poor heat insulation, and as a result, the film actually rises. The temperature to be heated varies depending on each part, and uniform perforation cannot be performed.

As described above, the heat-sensitive stencil plate using Washi as a support has the effects of (a) and (b) or (c) described above, resulting in a low print image density, a faint area, a high density area, etc.
In addition, there is a problem that the resolution is poor because the holes are not formed uniformly.

On the other hand, when a mesh sheet is used as the support, the above problems can be almost solved, but the price is too high to be used as the support of the heat-sensitive stencil original plate, and it is not used except for special applications. However, in spite of the above problems, almost all Japanese paper is used as the support.

The above-mentioned Japanese Patent Publication No. 49-5934 relating to the applicant of the present invention, which has been proposed for the purpose of solving such a problem, describes "a method of assembling a substantially closed shape assembling method pattern on a thermoplastic resin film". `` Thermal thermal transfer printing base paper having a heat-resistant resin layer that does not substantially soften and melt at the temperature at which the film is perforated '' is superior in that a good printed image can be obtained unlike the one using Washi as a support. However, it still had the following problems.

That is, gravure, offset or flexographic printing as a means for forming a heat-resistant resin layer of a substantially closed shape assembling pattern on a thermoplastic resin film that does not substantially soften or melt at the temperature at which the film is perforated. When the method is used, it is inexpensive, but even if the gravure printing method capable of forming the thickest heat-resistant resin layer is used, only the resin having a thickness of about 50% of the gravure depth can be transferred onto the film. When the solid content of the resin liquid forming the resin layer is low, the heat-resistant resin layer becomes thinner and the support lacks strength and printing durability. Furthermore, the shape regulated by gravure may break during the process of transferring the resin liquid from the gravure onto the film and curing or film formation.In severe cases, a uniform heat-resistant thin film results in a part with poor perforation. However, there was a problem of lacking in quality stability.

On the other hand, the original plate obtained by uniformly coating the film with a resin that crosslinks into three-dimensional by light irradiation and irradiating with light according to a pattern and removing the uncrosslinked resin in the unexposed portion with a solvent has a desired support thickness. The quality of the printed image and printing durability are satisfactory, but Japanese paper should be used due to loss due to the use of solvents, washing out uncrosslinked parts, and washing out the resin that crosslinks into three-dimensional structure by light irradiation. There was also a problem that it was considerably expensive compared to the one used.

(Means and Actions for Solving Problems) The inventors of the present invention have not deteriorated the print image quality as in the conventional heat-sensitive stencil plate using Washi as a support, and have a heat-sensitive stencil plate using a mesh sheet. As described above, the present invention has been completed as a result of earnestly examining the production of a heat-sensitive stencil original plate which is not expensive and has excellent printed image quality.

That is, the present invention leaves a pattern in which a large number of substantially closed shapes are closely and independently arranged on the surface, and a roll or an endless belt (hereinafter referred to as a gravure roll etc.) having a concave portion in which the remaining portion is etched. The radiation-curable resin liquid is applied to the surface, the resin liquid other than the recesses is removed, and the film is brought into close contact with the resin liquid only in the recesses. After the resin is cured, the film and the radiation-curable resin are brought into close contact with each other, and then the film and the radiation-cured resin adhered thereto are separated from the gravure roll or the like.

The substantially closed shape pattern in the present invention is an assembly of portions surrounded by continuous lines that are substantially closed like a mesh, and is a circle, an ellipse, a square, a rhombus, or a polygon. Alternatively, any combination of these may be used, but a circular shape is relatively preferable.

The size of the shape can be arbitrarily selected according to the purpose of use, the characteristics of the printing machine, the characteristics of the ink, and the like. However, for example, in the case of a circular shape, it is generally desirable to be about 20 μφ to 150 μφ. Further, the aggregate density of the shape can be arbitrarily selected according to the desired resolving power, but in general, a higher density is preferable, and when the shape is circular, for example, 50 mesh or more, more preferably 120 mesh or more. .

As a means for forming the concave portion of such an aggregate, a known means for producing a gravure printing plate can be preferably adopted.

The radiation-curable resin liquid used in the present invention means a resin liquid that can be cured by electron beams or ultraviolet rays, and a liquid that can be heated to become liquid even if it is not liquid at room temperature can be preferably used. Such radiation-curable resin liquid is well known to those who handle the radiation-curable resin liquid, and examples thereof include polyester acrylate, epoxy acrylate, urethane acrylate, polyether acrylate, melamine acrylate, alkyd acrylate, and acrylic. Acrylate,
For example, vinylpyrrolidone, 2-ethylhexyl acrylate, 2-hydroxydiethyl acrylate, 2-hydroxyethyl acrylate, 2-
Hydroxypropyl acrylate, 2-hydroxyethyl acryloyl phosphate, carbitol acrylate, phenoxyethyl acrylate, tetrahydrofurfryl acrylate, isobornyl acrylate, dicyclopentanyloxyethyl acrylate, N, N'-
Dimethylaminoethyl acrylate, 2- (N-methylcarbamoyl) acrylate, 1,3 butanediol diacrylate, 1,4 butanediol diacrylate, 1,6-
Hexanediol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, neopentyl glycol diacrylate, hydroxypipalinate neopentyl glycol diacrylate, 1,3-bis ( 3'-acryloxyethoxy-2'-hydroxypropyl) -5,5-dimethylhydantoin, trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate, etc. Add an appropriate amount considering the physical properties of the final cured product, and further, if necessary, a storage stabilizer, dye, pigment, wax, silicones,
An electron beam curable resin liquid containing a viscosity control agent, a surface tension control agent plasticizer, etc., such as acetophenone, 2,2-diethoxyacetophenone, p-dimethylaminoacetophenone, p-dimethylaminopropio Phenone, benzophenone, 2-chlorobenzophenone, p,
p'-dichlorobenzophenone, p, p'-diethylaminobenzophenone, Michler's ketone, ventil, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-
n-propyl ether, benzoin isobutyl ether, benzyl methyl ketal, tetramethyl thiuram monosulfide, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, azobisisobutyronitrile, benzoin peroxide, di-tert-butyl Peroxide, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-one, 1- (4-isopropyl) -2-hydroxy-2-methylpropan-1-one, methylbenzoylphore One or more photopolymerization initiators such as mate are added, and if necessary, amines such as n-butylamine, di-n-butylamine, triethyleneamine, triethylenetetramine, allylthiourea, o-tolylthiourea, etc. Urea series Compound, sodium diethyldithiophosphate, s-benzyl-iso-thiuronium-
Sulfur compounds such as p-toluenesulfinate, general formula (In the formula, R ₁ and R ₂ are selected from a methyl group, an ethyl group, a β-cyanoethyl group or a β-chloroethyl group), an N, N-disubstituted-p-aminobenzonitrile compound, tri -Phosphine compounds such as n-butylphosphine, sodium and diethyldithiophosphate, N-nitrosohydroxylamine derivatives, other nitrogen compounds such as oxazolidine compounds and tetrahydro-1,3-oxazine compounds, chlorine compounds such as carbon tetrachloride and hexachloroethane ,
One or more sensitizers such as toluethanolamine triacrylate may be added to give a resin liquid or the like capable of being cured by ultraviolet rays.

Any method may be used to apply these resin liquids to the gravure roll or the like, but for example, the liquid is put in a pan and the gravure roll or the like is immersed in the liquid, and the liquid is applied from the pan to the gravure roll or the like via a pickup roll or fountain. Alternatively, the liquid may be cast on a gravure roll or the like. At this time, it is also effective to heat the resin solution, gravure roll, etc. to an appropriate temperature in order to appropriately control the viscosity of the resin solution.

When the resin liquid is applied to the gravure roll in this way,
Naturally, the resin liquid is applied to other than the concave portion, but in order to remove the adhered resin other than the concave portion, the metal or resin doctor knife is pressed against the gravure roll to remove the resin liquid other than the concave portion, and only the concave portion is removed. It suffices if the resin liquid is present.

The film used in the present invention may be one that can be melt-shrink-perforated by heat, and for example, a stretched film of a thermoplastic resin such as polyester, polypropylene, polyvinyl chloride, or polyvinylidene chloride is preferably used. To be The thickness of the film is preferably about 1 to 20 μm.

Furthermore, the adhesion between the film and the radiation curable resin is 1.5 g / cm
If it is above, there is no particular problem in practice, but if necessary to improve the adhesion, the surface to be bonded with the radiation curable resin may be corona treated beforehand, or an intermediate layer may be interposed to improve the adhesion. A means for increasing the adhesive strength may be used together.

The material used as the intermediate layer may be appropriately selected depending on the type of radiation curable resin and the type of film used,
For example, imine-based, titanate-based, isocyanate-based anchoring agents and polyvinyl acetate, polyacrylate, polymethacrylate, polyvinyl chloride, vinyl chloride / vinyl acetate copolymer, polyvinylidene chloride, polyacrylonitrile, polyvinyl ether, polycarbonate, thermoplastic polyester,
Polyamide, diene plastic, polyurethane plastic, chlorinated polyethylene, chlorinated polypropylene, polyvinyl butyral, cellulosic plastic, polyvinylpyrrolidone, fumaron indene resin, natural rubber, butadiene rubber, etc. alone or mixed, dissolved in a solvent After that, the emulsion may be applied to the film. Further, additives such as a plasticizer, a dye and a pigment may be added to these. The thickness of the intermediate layer is thin and sufficient, and about 0.01 μm to 2 μm is sufficient.

In addition, as a method of bringing the film into close contact with the resin liquid only in the concave portions, for example, a roll capable of pressing a gravure roll or the like may be used to bring the film into close contact. Further, the portion may be put under reduced pressure so as not to entrap air between the film at the time of press contact.

Thus, by irradiating the film with the film in close contact with the resin liquid only in the recesses and curing and adhering the resin liquid, a bonded body having a single film part corresponding to the pattern of the recess assembly can be reliably formed. Then, the film and the bonded body made of the radiation-cured resin adhered to the film are peeled off from the gravure roll or the like, and a release agent such as a fluorine compound or a silicon compound is applied to the surface of the gravure roll or the like so as to facilitate the peeling. It is also effective to leave it.

As described above, the reason why the resin liquid applied to the gravure roll or the like is limited to the radiation curable resin in the present invention has been variously examined. (A) The film used for the heat-sensitive stencil original plate has the property of being softened or melted and shrunk by heating. When a thermosetting resin liquid is used, when the resin liquid is heated and cured,
Even if the film is not perforated, shrinkage generally starts and it is not possible to make a base paper with good flatness. (B) There are room-temperature curing type and moisture curing type curable resin liquids, but it takes time to cure. As a result, productivity is poor and the cost is high. (C) When a resin solution or emulsion dissolved in a solvent is used as the resin solution, it is necessary to adhere it with a film and perform heat film formation. Not only does it have the same problem as item b), but since the film covers the gravure roll and the like closely, the film partially floats from the gravure roll and the like due to the generation of solvent vapor, and the resin film of the desired shape is formed. There is a problem that the resin cannot be formed, and the use of the radiation-curable resin makes it possible to achieve the object of the present invention without the above problems.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1 FIG. 1 is a schematic view showing an example of the manufacturing method of the present invention.
In FIG. 1, a roll having 160 circular non-recesses of about 80 μφ per 25.4 mm length (hereinafter referred to as “reverse gravure roll”), the depth of the recesses is 39 μ, and the roll surface has Frontier Ceraco B manufactured by Frontier Co., Ltd. was applied in advance to form a strong release film of tetrachloroethylene-ceramic film. The roll is 6
It was warmed to 0 ° C. 2 is an electron beam irradiation device, which has a primary shield. 3 is a pan in which the radiation-curable resin liquid is put, and in this embodiment, the pan is heated to 75 ° C. 4 is a radiation curable resin liquid, and the following composition was used in this example.

Resin liquid composition 5 is a puff-up roll of resin liquid, and in this embodiment, the roll is also heated to 75 ° C. 6 is a doctor knife for removing the resin liquid other than the concave portion applied to the reverse gravure roll 1. Reference numeral 7 denotes a nip roll, which is a roll for bringing the fed film into close contact with the reverse gravure roll 1. Reference numeral 8 is a film feeding roll, and 9 is a composite of a cured resin film and a film in which a resin liquid remaining only in the recess assembly is cured in a state of being adhered to the film and a film integrated with the film. And 10 is a corona treatment machine for improving the adhesion between the film and the radiation curable resin, 11 is a take-up roll for the composite 9, 12 is another nip roll, and 13 is a first for stability. It is a secondary radiation shield.

In this embodiment, the resin liquid having the above composition is used as the radiation curable resin liquid, the resin liquid 4 is applied to the reverse gravure roll 1 by the pickup roll 5, and the resin liquid other than the concave portion is removed by the doctor knife 6 to form the concave portion. Only the resin liquid was present. Next, a polyester film having a thickness of 4 μm is fed from the film feeding roll, the contact surface with the reverse gravure roll 1 is subjected to corona treatment, and the film is brought into close contact with the reverse gravure roll 1 by the nip roll 8 and irradiated with an electron beam in this state to form concave portions. The remaining resin liquid was cured. The composite of the resin film and film cured at the 12th position of the other nip roll was peeled off from the reverse gravure roll 1 and wound up. In this way, a heat-sensitive stencil original plate according to the production method of the present invention was obtained.

As a result of observing the thus obtained heat-sensitive stencil plate under a microscope, it was confirmed that there was 160 parts in which there was only a film of about 80 μφ in a regular arrangement per 25.4 mm length. . The thickness of the composite was approximately 43 μm.

Sodium stearate (0.5 g / m ^{2) was} applied to the film surface of the thus obtained heat-sensitive stencil original plate to impart releasability from the original. The film surface of the heat-sensitive copy original plate thus obtained was overlaid on the original, and the result was printed with a heat-sensitive plate making machine (lithograph FX-7200 manufactured by Riso Kagaku Kogyo Co., Ltd.), resulting in extremely sharp and good resolution, and uneven image density. A high-quality print similar to that of a desk-top offset print was obtained. As a precaution, I tried printing 3000 sheets, but the original did not tear at all, and the print quality was the same as when printing started, and a high-quality printed matter was obtained. For comparison, a commercially available thermosensitive printing original plate with a Japanese paper as a support was used, and as a result of plate making and printing in the same manner as above, density unevenness was particularly remarkable at solid parts and sharpness was considerably inferior to the product of the present invention. there were.

Example 2 A schematic diagram showing an example of the manufacturing method of the present invention shown in FIG. 1 is shown in FIG. 1 except that an ultraviolet irradiation device is used instead of the electron beam irradiation device 2 and the secondary shield is removed. A heat-sensitive stencil original plate according to the production method of the present invention was prepared by the following method using the apparatus shown in the schematic view.

Radiation curable resin liquid used Film used: 2 μm thick polyester film Using the above materials, the reverse gravure roll 1, the pan 3 and the pickup roll 5 shown in FIG. 1 were heated to 40 ° C. and the same as in Example 1. A heat-sensitive stencil original plate was prepared by the method of the invention.

The result of observing the heat-sensitive stencil plate thus obtained with a microscope 2
It was confirmed that the composite was a regular array per 5.4 mm length, in which 160 portions of only a film layer having a size of about 80 μφ existed. The thickness of the composite was about 40μ.

0.4 g / m ² of a surfactant (Emulgen 905 manufactured by Kao Corporation) was applied to the film surface of the heat-sensitive stencil original plate thus obtained,
Printing was performed with a thermal head (Matsushita Electric Central Research Laboratory, long-distance printing device).

As a result of printing on a rotary press using the stencil printing plate thus printed, a high-quality printed matter which was extremely sharp, which was faithful to the dots of the thermal head, and which had no image density unevenness was obtained.

(Effects of the Invention) As described above, according to the method of the present invention, the heat-sensitive stencil original plate having a uniform size, shape, and distribution of the porous openings, that is, the openings each of which can serve as an image element. Can be easily prepared, and by using the heat-sensitive stencil original plate obtained by the method of the present invention, a high-quality printed matter such as a desk-top offset printed matter can be easily obtained by a simple printing means called stencil printing.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an example of the manufacturing method used in Example 1 of the present invention.

Claims (1)

[Claims] 1. A radiation-cured surface of a roll or an endless belt having a recess in which a large number of substantially closed shapes are closely and independently arranged, and the remaining portion is etched. Mold resin liquid is applied to remove the resin liquid other than the concave portion, the thermoplastic resin film is brought into close contact with the resin liquid only in the concave portion, and radiation is irradiated from the thermoplastic film side to cure the radiation curable resin. A method for producing a heat-sensitive stencil original plate, which comprises peeling the thermoplastic film and the radiation-cured resin adhered thereto from a roll or an endless belt after adhering the thermoplastic resin film and the radiation-curable resin.