JP2000198279A - Heat-sensitive stencil base sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To print an image to be desired to be printed as an assembly of fine halftone dots by providing a second layer having holes of halftone dots on one surface of the first layer made of thermoplastic resin film, and setting a halftone dot areal rate of holes of the second layer to a specific ratio or below. SOLUTION: A second layer 1 having holes of halftone dots is formed on one surface of a first layer made of a thermoplastic resin film 2, and a porous support 4 is laminated on the other surface of the film 2. Here, a halftone dot areal rate of holes of the layer 1 is set to 50% or below. Liquid droplets of a photothermal conversion material-containing liquid 6 are discharged from a liquid discharger 5 onto the layer 1. Then, when a light beam 10 from a light source 8 is emitted to the layer 1, a photothermal conversion material 7 is heated. Then, the film 2 absorbs a heat at a site covered with the layer 1 by the layer 1, it is not melted, but the site of the hole of the layer 1 is melt perforated by the heat generated from the layer 7 and engraved.

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 sheet, and more particularly, to a heat-sensitive stencil sheet capable of stencil printing an image as an aggregate of a large number of independent fine dots.

[0002]

2. Description of the Related Art Conventionally, as a method for making a heat-sensitive stencil sheet, for example, (1) an original in which characters or the like are handwritten with a writing instrument containing carbon such as a pencil, or a toner image original copied by an electrophotographic method, and A method of superimposing a stencil sheet, heating a character portion or an image portion of the original with light of a flash lamp, an infrared lamp, or the like, and melting and perforating a thermoplastic resin film of the thermosensitive stencil sheet in contact with the stencil sheet, (2) Using a thermal head that generates dot-like heat so as to reproduce an image such as a character according to image information obtained by converting the image into an electric signal, the thermal head is brought into contact with a heat-sensitive stencil sheet, and the thermoplastic resin of the stencil sheet is used. A method for melt-perforating a film is known.

However, in the plate making method of the above (1),
Poor adhesion between the thermoplastic resin film of the heat-sensitive stencil paper and the toner image portion of the original or copy that generates heat may cause perforation failure, or dust on the surface of the original or toner in the non-image portion may generate heat, and However, there is a problem that a portion other than the perforated portion is perforated, that is, a so-called pinhole.

Further, in the plate making method of the above (2), there are problems such as poor perforation due to uneven pressing pressure of the heat-sensitive stencil paper against the thermal head, wrinkling of the heat-sensitive stencil paper, and poor conveyance. was there. further,
In order to efficiently and quickly make and print heat-sensitive stencil paper by the stencil printing method of (2), make the stencil paper with the side opposite to the side where the thermal head comes into contact with the stencil printing ink beforehand. In this case, it is proposed that the ink contacting the heat-sensitive stencil paper increases the non-uniformity of the pressing pressure of the thermal head or that the heat of the thermal head transfers to the ink contacting the heat-sensitive stencil paper. The heat-sensitive stencil paper cannot be provided with a sufficient amount of heat to perforate the heat-sensitive stencil paper, resulting in poor perforation.

In order to improve such a drawback, a heat-sensitive stencil sheet having a liquid absorbing layer and a light reflecting layer is used to reproduce a desired image on a stencil sheet from a liquid discharger by using a liquid containing a photothermal conversion material. To be transferred in the form of dots
A method of irradiating the stencil sheet with visible light or infrared light and selectively perforating a portion to which the liquid has transferred in a non-contact step to make a stencil sheet (Japanese Patent Application Laid-Open No. 9-99664) has been proposed. However, satisfactory results have not yet been obtained in the independence of the perforated dots, and the sharpness of the printed image has also been insufficient.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a heat-sensitive stencil sheet capable of printing an image to be printed as an aggregate of fine halftone dots. It is in.

[0007]

According to the present invention, the above object is attained by providing a first layer made of a thermoplastic resin film and a second layer having a dot-like perforation provided on at least one surface thereof. The heat-sensitive stencil sheet is characterized in that the stencil sheet has a halftone dot area ratio of not more than 50%.

That is, the present invention is characterized in that a thermoplastic resin film of a heat-sensitive stencil sheet is used as a first layer, and a second layer having dot-like perforations is provided on the surface thereof. Therefore, the heat-sensitive stencil sheet of the present invention is advantageous in that the heat capacity is different between the overlapping portion of the first layer and the second layer and the perforated portion of the second layer. That is, since the perforated portion of the second layer has a smaller heat capacity than the overlapping portion,
At the time of plate making, even if heat is applied to a region extending between the two, the first layer is preferentially melt-punched at the portion of the perforated portion of the second layer, while melting overlap is hindered at the overlapping portion. Is done. Therefore, it is possible to selectively generate the molten perforation of the first layer made of the thermoplastic resin film at the portion of the perforated portion of the second layer. As a result, the perforated portion of the stencil sheet is formed by independent dot-shaped perforation. Can be formed as an aggregate. Thus, at the time of printing, the printing ink is transferred not only to the perforated portion of the thermoplastic resin film but also to the printing medium through the dot-shaped perforations of the second layer, so that the printed image is a set of fine dots. Obtained as a body.

As described above, the second layer has a function as a perforation inhibition layer of the first layer. In other words, in the heat-sensitive stencil sheet of the present invention, at the time of stencil making, the first layer made of the thermoplastic resin film is formed by the heat of the light-to-heat conversion material attached to the stencil sheet or the heat of the thermal head. At the location of the perforated part, while being raised to the melting temperature and perforated,
At the overlap with the second layer, no perforation occurs so that the second layer absorbs part of the heat and keeps the temperature of the first layer below the melting temperature.

[0010] In order to selectively cause melt perforation of the thermoplastic resin film at the perforated portion of the second layer, the second layer of the present invention desirably has a large specific heat. , 1.0 J / g · K or more, more preferably 1.5 J / g · K or more. If the specific heat of the second layer is smaller than the specific heat of the thermoplastic resin film, the temperature of the thermoplastic resin film rises due to the heat generated from the photothermal conversion material or the thermal head, and as a result, the thermoplastic resin film May be melted and perforated at locations other than the perforated portion of the second layer.

The second layer is made of an inorganic compound (specific heat 0.5 to 1 J / g).
K), an organic compound (specific heat 1.0 to 3 J / gK), or an organic polymer compound (specific heat 1 to 2.5 J / gK), which can be used alone or You may mix and use. A material having a higher specific heat is preferable because the thickness of the second layer can be reduced. Further, the second layer is preferably made of a material having low light absorption and high light reflectivity with respect to visible light or infrared light in order to prevent heat generation due to irradiated light.

The material used for the second layer is, for example, an inorganic material such as talc, clay, calcium carbonate, magnesium carbonate, titanium oxide, aluminum oxide, silicon oxide, zinc oxide, barium sulfate, lead sulfate, and kaolin. Compound fine particles, and polyvinylpyrrolidone, ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer, polyvinyl acetal, polyacrylamide, polystyrene, polyvinyl acetate, acrylic resin, polyamide And organic polymer compounds such as polyester, polycarbonate, polyurethane, chlorinated rubber, and chlorinated polyolefin. Furthermore, if necessary, a dye, a pigment, a curing agent, and the like can be contained.

For the second layer, for example, the above materials are mixed in a liquid, and the mixture is applied onto the first layer made of a thermoplastic resin film by a coating means such as a gravure coater or a roll coater, and dried. Can be formed. Also,
A film previously perforated by a perforation device such as a maxima laser device may be laminated as a second layer on the first layer. The second layer may be provided on one or both surfaces of the first layer, and may be heated from either surface during plate making.

In the present invention, it is necessary that the second layer formed on the first layer made of the thermoplastic resin film has a dot-like perforation, that is, a large number of mutually independent openings. is there. The shape of the perforations may be, for example, rectangular, circular, rhombic, or the like. The halftone dot area ratio of the perforation is 50%
It is necessary to make the following, preferably 50 to 5%
It is. Here, the dot area ratio refers to the ratio of the area of the perforations of the second layer per unit area of the first layer. If the halftone dot area ratio is larger than 50%, the adjacent perforations merge with each other, so that an image composed of a large number of independent fine dots cannot be obtained. On the other hand, if the dot area ratio is less than 5%, the ink permeability may be poor, and a good image may not be obtained. The distribution of perforations in the second layer is as large as possible per unit area, and a clear print can be obtained if the perforations are arranged regularly. In the present invention, it is preferable that the perforations of the second layer are regularly arranged at 50 or more per inch, preferably 100 or more per inch.

The thermoplastic resin film used in the present invention includes, for example, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyethylene terephthalate, polybutylene terephthalate, polynaphthalene terephthalate, polysulfone sulfide, polystyrene, polyurethane, polycarbonate, polycarbonate and the like. Vinyl acetate, acrylic resin, silicone resin and the like are used. These resin components may be used alone or as a mixture, or may be used as a copolymer thermoplastic resin film.
Further, the thermoplastic resin film may be white.

The thickness of the thermoplastic resin film is preferably in the range of 0.5 to 50 μm, particularly preferably in the range of 1 to 20 μm. If the thickness of the film is less than 0.5 μm, the handleability and strength are poor, and if it exceeds 50 μm, a large amount of heat energy is required at the time of perforation, which is not economical.

The heat-sensitive stencil sheet of the present invention may be provided with a porous support on either side. Examples of such a porous support include natural fibers such as manila hemp, pulp, mitsumata, mulberry, Japanese paper, polyester, nylon, vinylon,
Thin paper, nonwoven fabric, screen gauze, and the like using synthetic fibers such as acetate, metal fibers, glass fibers, or the like, alone or in combination. The basis weight of these porous supports is 1-2.
Range of 0 g / m ^2, more preferably from 5 to 15 g / m ^2. If it is less than 1 g / m ² , the strength as a base paper will be weak, and if it exceeds 20 g / m ² , the ink permeability during printing may be poor. Also, the thickness of the porous support is 5-100 μm
Is more preferable, and more preferably 10 to 50 μm. If the thickness is less than 5 μm, the strength as a base paper is still weak, and if it exceeds 100 μm, the ink permeability during printing may be poor.

The heat-sensitive stencil sheet of the present invention can be made by any known plate-making method.
As described in -99664 or the like, a liquid containing a light-to-heat conversion material is discharged from a liquid discharger onto a heat-sensitive stencil sheet and transferred to the heat-sensitive stencil sheet, and then the heat-sensitive stencil sheet is irradiated with visible light or infrared light. Thus, it is suitable for making a plate by a plate making method in which a portion of the heat-sensitive stencil sheet to which the light-to-heat conversion material is transferred is selectively perforated to make a plate. In this stencil making method, the liquid containing the light-to-heat conversion material is discharged in an image form from the liquid discharge device. Therefore, when the liquid is transferred onto the heat-sensitive stencil sheet, the transferred liquid is prevented from bleeding and spreading, further preventing repulsion and providing a desired image. In addition, a liquid absorbing layer may be provided on the surface of the heat-sensitive stencil paper in order to faithfully form the ink and to promote absorption and drying of the liquid. It is necessary that the liquid absorbing layer is perforated by heat similarly to the thermoplastic resin film.

The liquid absorbing layer is adjusted such that the contact angle between the absorbing layer and the liquid containing the light-to-heat conversion material is transferred in the range of 20 to 150 degrees, preferably in the range of 30 to 130 degrees. Is done. If the contact angle is less than 20 degrees, the transferred liquid will bleed or spread on the absorbing layer, and if the contact angle is greater than 150 degrees, the liquid will be repelled on the absorbing layer, a so-called repelling phenomenon. Become. Therefore, a polymer compound having a high affinity for a solvent used as a liquid containing a light-to-heat conversion material is used for the absorption layer, and a water-repellent compound may be appropriately added thereto.

As the polymer compound used in the absorbing layer, when the main component of the solvent of the liquid containing the photothermal conversion material is aqueous, for example, polyvinyl alcohol, methyl cellulose, polyvinyl alcohol, ethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose,
Polyvinyl pyrrolidone, ethylene-vinyl alcohol copolymer, polyethylene oxide, polyvinyl ether, polyvinyl acetal, polyacrylamide and the like are used. These resin components may be used alone or as a mixture or as a copolymer.

If the main component of the solvent of the liquid containing the photothermal conversion material is an organic solvent, the polymer may be, for example, polyethylene, polypropylene, polyisobutylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, or polyvinyl fluoride. , Polyvinyl acetate, acrylic resin, polyamide, polyimide, polyester, polycarbonate, polyurethane and the like. These resin components may be used alone or as a mixture or as a copolymer.

Examples of the water-repellent compound include compounds such as fluorine compounds, silane compounds, waxes, higher fatty acids, higher fatty acid amides, and polyolefins. Resin, ethylene tetrafluoride-hexafluoropropylene copolymer, ethylene tetrafluoride-perfluoroalkyl vinyl ether copolymer, silicone resin, dimethyl silicone oil, methylphenyl silicone oil, cyclic dimethyl siloxane, modified silicone oil, carnauba wax , Microcrystalline wax, polyethylene wax, montan wax, paraffin wax, candelilla wax, shellac wax, oxidized wax, ester wax, beeswax, wood wax, spermaceti, stearic acid, lauric acid, behenic acid, Prong acid, palmitic acid, stearic acid amide, lauric acid amide, behenic acid amide, caproic acid amide, palmitic acid amide, polyethylene,
Polypropylene and the like. The water-repellent compound may be either a solid powder or a liquid, and is used in a dissolved or dispersed state in the liquid absorbing layer.

Further, the liquid absorbing layer may contain organic and inorganic fine particles in order to promote absorption and drying of the liquid containing the photothermal conversion material on the liquid absorbing layer. For example, polyurethane, polyester, polyethylene, polystyrene, polysiloxane, phenolic resin,
Organic fine particles of high molecular compounds such as acrylic resin and benzoguanamine resin, talc, clay, calcium carbonate,
Examples include fine particles of an inorganic compound such as titanium oxide, aluminum oxide, silicon oxide, and kaolin.

The liquid absorption layer is formed by mixing a liquid obtained by mixing the above-mentioned polymer compound and, if necessary, a water-repellent compound and / or fine particles.
It can be obtained by applying to a heat-sensitive stencil base paper with a coating means such as a gravure coater or a wire bar coater and drying it. Further, the liquid absorbing layer may be provided by sequentially laminating a second layer and a liquid absorbing layer on a thermoplastic resin film constituting the first layer, or conversely, a liquid absorbing layer and a second layer. May be sequentially laminated.

The liquid containing a light-to-heat conversion material used in the above-described plate making contains a light-to-heat conversion material for converting light energy into heat energy and a solvent as main components. The light-to-heat conversion material is preferably a material that efficiently converts light energy to heat energy. For example, carbon black, lamp black,
Silicon carbide, carbon nitride, metal powder, metal oxide, inorganic pigment,
Organic pigments, organic dyes and the like can be mentioned. Among these,
It is preferable to use a dye that has a large absorption in a specific wavelength range, such as a phthalocyanine dye, a cyanine dye, a squarylium dye, and a polymethine dye.

The solvent used for the photothermal conversion material-containing liquid is
Aliphatic hydrocarbons, aromatic hydrocarbons, alcohols,
Solvents such as ketone-based, ester-based, ether-based, aldehyde-based, carboxylic-based, amine-based, low-molecular-weight heterocyclic compounds, oxides, and water are exemplified. Specifically, hexane, heptane, octane, benzene, toluene, xylene, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, butyl alcohol, ethylene glycol, diethylene glycol, propylene glycol, ethylene glycol monomethyl ether, diethylene glycol diethyl Ether, glycerin, acetone, methyl ethyl ketone, ethyl acetate,
Propyl acetate, ethyl ether, tetrahydrofuran,
Examples thereof include 1,4-dioxane, formic acid, acetic acid, propionic acid, formaldehyde, acetaldehyde, methylamine, ethylenediamine, dimethylformamide, pyridine, 2-pyrrolidone, and N-methyl-2-pyrrolidone. These can be used alone or in combination. If necessary, dyes, pigments, fillers, binders, curing agents, preservatives, wetting agents, surfactants, pH adjusters, and the like can be contained.

As the liquid discharger used in the plate making method described above, for example, 10 to 2000 (10 to 2000 d
pi) Connect a nozzle, slit, porous material, porous film, etc. having an opening to a piezoelectric element, a heating element, a liquid feed pump, etc., and intermittently or continuously liquid according to an electric signal of a character image. That is, there is an apparatus that discharges in the form of dots or lines.

As a device for irradiating visible light or infrared light used in the plate making method, a xenon lamp, a flash lamp, a halogen lamp, an infrared heater, and the like can be used.

The heat-sensitive stencil sheet of the present invention can be used for general stencil printing after plate making. For example, the ink is placed on one surface of the stencil sheet made, and the printing paper is overlaid on the other surface, and the ink is pressed, depressurized, passed through the perforated portion by means of a squeegee, etc., and the ink is applied to the printing paper. The printed matter can be obtained by transfer.

The stencil printing ink includes oil-based ink, water-based ink, water-in-oil droplet (W /
O) emulsion ink, oil-in-water (O / W) emulsion ink, hot melt ink, and the like are used.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to these embodiments.

FIG. 1 is a schematic sectional view showing a specific example of the heat-sensitive stencil sheet of the present invention and a plate making mechanism thereof. FIG.
The heat-sensitive stencil sheet of the present invention has a second layer 1 having a dot-like perforation on one surface of a first layer made of a thermoplastic resin film 2.
And a porous support 4 is laminated on the other surface of the thermoplastic resin film 2. As shown in FIG. 1A, when a droplet of the photothermal conversion material-containing liquid 6 is ejected from the liquid ejection device 5 onto the second layer 1, as shown in FIG. The conversion material 7 may transfer over the upper surface of the second layer 1 and the perforations. Here, as shown in FIG. 1C, when a light beam 10 is applied to the second layer 1 from a light source 8 having a light reflecting plate 9, the photothermal conversion material 7 generates heat.
At that time, as shown in FIG. 1 (d), the thermoplastic resin film 2 does not melt because the heat is absorbed by the second layer 1 at the portion covered by the second layer 1, The perforated portion of the second layer 1 is melt-perforated by the heat generated by the light-to-heat conversion material 7 and plate making is performed. As described above, the heat-sensitive stencil sheet of the present invention can be used as shown in FIG. 3 (a) even if the photothermal conversion material 7 is transferred to a solid image.
As shown in (b), since the thermoplastic resin film 2 is selectively perforated only at the perforated portion of the second layer 1, the stencil making section 11 of the stencil sheet always has a set of independent dot-shaped perforations. Obtained as a body.

FIG. 2 is a schematic sectional view showing another embodiment of the heat-sensitive stencil sheet of the present invention and a plate making mechanism thereof. The heat-sensitive stencil sheet of FIG. 2 has a second layer 1 having a dot-like perforation formed on one surface of a first layer made of a thermoplastic resin film 2, and the other surface of the thermoplastic resin film 2. A liquid absorbing layer 3 is formed on the porous support 4
Are laminated. As shown in FIG. 2A, when a droplet of the photothermal conversion material-containing liquid 6 is ejected from the liquid ejection device 5 onto the liquid absorbing layer 3, the photothermal conversion is performed as shown in FIG. 2B. The material 7 is transferred to the liquid absorbing layer 3. Here, as shown in FIG. 2C, the light source 8 with the light reflecting plate 9 is provided.
When the light absorption layer 3 is irradiated with the light beam 10 from the above, the photothermal conversion material 7 generates heat. At that time, as shown in FIG.
Although the thermoplastic resin film 2 does not melt at the portion overlapping with the second layer 1 because heat is absorbed by the second layer 1, it does not melt at the portion where the second layer 1 is perforated.
Is perforated by the heat generated by the heat treatment and plate making is performed. Therefore, as shown in FIG. 3, even if the photothermal conversion material 7 is transferred to the liquid absorbing layer 3 in a solid image shape, as in the stencil sheet of FIG. Is selectively perforated only at the perforated portion, so that the stencil making section 11 of the stencil sheet is always obtained as an aggregate of independent dot-shaped perforations.

[0034]

EXAMPLE 1 A polyester film having a thickness of 4 μm was used as a first layer, and 5 parts by weight of an acrylic resin, 5 parts by weight of a urethane resin, 5 parts by weight of calcium carbonate, 25 parts by weight of isopropyl alcohol, and 40 parts by weight of toluene Of a mixed solution consisting of 20 parts by weight of ethyl acetate and 300 parts / inch of a gravure coater having a regular halftone dot area ratio of 60%, and dried to form a second layer having a thickness of 3 μm. The second layer was provided with dot-like perforations having an area ratio of 40%, and the specific heat was 2.4 J / g · K. Next, a 200-mesh polyester fabric was stuck on the side of the film opposite to the second layer to produce a heat-sensitive stencil sheet.

Next, a light-to-heat conversion material comprising 3 parts by weight of carbon black, 27 parts by weight of propylene glycol, 20 parts by weight of 2-pyrrolidone, and 50 parts by weight of water was formed on the second layer of the obtained heat-sensitive stencil sheet. When the liquid is transferred in an image form from a liquid ejection device having a nozzle of 600 dpi resolution, and the solvent of the liquid is evaporated, an image mainly composed of carbon black is formed as a continuous image portion on the heat-sensitive stencil paper. Was. When the image portion is irradiated with light from Xenon Flash SP275 (manufactured by Riso Kagaku Corporation), the heat generated from the image portion causes the thermoplastic resin film of the heat-sensitive stencil paper to
The heat-sensitive stencil sheet having a stencil making unit composed of an aggregate of independent perforations corresponding to a dot image of 300 dpi was obtained by performing melt perforation only at the perforated portion of the second layer in the image portion.

A high-mesh ink (trade name: Riso Kagaku Kogyo Co., Ltd.) is placed on the polyester fabric side of the perforated heat-sensitive stencil paper, and a simple stencil printing machine, Print Gokko (registered trademark: Riso Kagaku Kogyo Co., Ltd.) ), A clear image was obtained.

Example 2 2 parts by weight of carboxymethyl cellulose and 1 part by weight of an aqueous silicone oil were added to a 4 μm-thick polyester film.
A mixture of 1 part by weight of silicon oxide, 70 parts by weight of water and 26 parts by weight of isopropyl alcohol was applied by a roll coater and dried.
A 5 μm liquid absorbing layer was provided. The film provided with the liquid absorbing layer is used as the first layer, and the thickness provided with the dot-shaped perforations having an area ratio of 40% on the liquid absorbing layer in the same manner as in Example 1.
A 3 μm second layer was formed. A thermosensitive stencil sheet was prepared by laminating Japanese paper having a basis weight of 10 g / m ² as a porous support on the side opposite to the second layer of the film.

Next, the liquid containing the light-to-heat conversion material is transferred from the liquid discharger to the image on the second layer of the obtained heat-sensitive stencil sheet in the same manner as in Example 1, and is transferred to the image area. When irradiated with xenon flash, the heat generated from the image area causes the thermoplastic resin film of the heat-sensitive stencil paper to melt and perforate only the perforated portion of the second layer in the image area,
A heat-sensitive stencil sheet having a stencil making unit consisting of an aggregate of independent perforations corresponding to a dot image of 0 dpi was obtained.

The prepressed heat-sensitive stencil sheet is wound around a drum of a rotary stencil printing machine lithograph (registered trademark) GR375 (manufactured by Riso Kagaku Kogyo Co., Ltd.) to which ink has been supplied in advance, and the drum is rotated. When the printing paper was conveyed while being pressed, a desired clear printed image was obtained.

Example 3 A polyester film having a thickness of 4 μm was used as the first layer, and 10 parts by weight of vinyl chloride-vinyl acetate copolymer, 5 parts by weight of polyamide, 5 parts by weight of titanium oxide, and 20 parts by weight of isopropyl alcohol A mixture of 40 parts by weight of toluene and 20 parts by weight of ethyl acetate is coated and dried with a gravure coater having a regular dot area ratio of 400 / inch and a halftone area ratio of 70% to form a second layer having a thickness of 4 μm. did. The second layer obtained here is the area ratio
It had 30% halftone dot perforations and a specific heat of 2.2 J / g · K. Next, a liquid absorbing layer similar to that of Example 2 was provided on the side of the film opposite to the second layer. Next, Japanese paper having a basis weight of 10 g / m ² was adhered to the second layer side of this film as a porous support to prepare a heat-sensitive stencil sheet.

Next, the liquid containing the light-to-heat conversion material was transferred from the liquid discharger to the liquid absorbing layer of the obtained heat-sensitive stencil sheet in the same manner as in Example 1, and the xenon flash was applied to the image area. When irradiated, the heat generated from the image area causes the thermoplastic resin film of the heat-sensitive stencil paper to melt and perforate only the perforated portion of the second layer in the image area,
A thermosensitive stencil sheet having a stencil made of an aggregate of independent perforations corresponding to the dot image of pi was obtained.

The thus-prepared heat-sensitive stencil sheet is wound around a drum of a rotary stencil printing machine RISOGRAPH (registered trademark) GR375 (manufactured by Riso Kagaku Kogyo Co., Ltd.) to which ink has been supplied in advance, and the drum is rotated. When the printing paper was conveyed while being pressed, a desired clear printed image was obtained.

[0043]

As described above, according to the present invention, a thermosensitive stencil sheet is formed by forming a thermoplastic resin film as a first layer and forming a second layer having dot-like perforations thereon. Therefore, at the time of heating plate-making, the thermoplastic resin film is perforated only at the perforated portion of the second layer, so that a plate-making portion comprising a group of a large number of independent perforations corresponding to the image is obtained,
It can provide clear printed matter.

[Brief description of the drawings]

FIG. 1A is a schematic cross-sectional view showing a specific example of a heat-sensitive stencil sheet of the present invention in a state in which a liquid containing a light-to-heat conversion material is discharged from a liquid discharge device, and FIG. Is a diagram similar to (a), showing a state in which the light-to-heat conversion material is transferred,
(c) shows the heat-sensitive stencil sheet of (b) exposed to light
It is a figure similar to (a), and (d) is a figure similar to (a) which shows the state in which the heat-sensitive stencil paper was made.

FIG. 2 shows another specific example of the heat-sensitive stencil sheet of the present invention.
FIG.

3A is a schematic plan view of the heat-sensitive stencil sheet of FIGS. 1 and 2 in the state of FIG. 3B, and FIG. 3B is a plan view of FIG.
FIG. 3 is a schematic plan view of the heat-sensitive stencil sheet of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Second layer 2 Thermoplastic resin film 3 Liquid absorption layer 4 Porous support 5 Liquid ejection device 6 Liquid containing light-heat conversion material 7 Light-heat conversion material 8 Light source 9 Light reflection plate 10 Light beam 11 Plate-making part

 ──────────────────────────────────────────────────の Continued on the front page F term (reference) 2H114 AB09 BA02 BA06 DA28 DA51 DA56 DA57 DA60 DA61 EA02 EA04 FA07 FA11 4F100 AA08H AA37H AK01A AK25 AK41 AK51 AR00B AR00C AR00D AR00E BA03 BA04 BA05 BA07 BA10 DCB DCB DC11 DC GB90 JA01B JA01E JB16A JD15D YY00B YY00E

Claims (6)

[Claims] A first layer comprising a thermoplastic resin film, and a second layer provided on at least one surface thereof and having a dot-like perforation, wherein perforation of the second layer is provided. Wherein the halftone dot area ratio is 50% or less. 2. The heat-sensitive stencil sheet according to claim 1, wherein the specific heat of the second layer is 1.0 J / g · K or more. 3. The heat-sensitive stencil sheet according to claim 1, wherein the dot-like perforations of the second layer are present in an amount of 50 or more per inch and are regularly arranged. 4. The heat-sensitive stencil sheet according to claim 1, further comprising a porous support on one side of the base sheet. 5. The heat-sensitive stencil sheet according to claim 1, wherein the first layer has a liquid absorbing layer on a surface of the thermoplastic resin film. 6. The heat-sensitive stencil sheet according to claim 5, wherein the second layer is provided on a liquid absorbing layer.