JP2011126071A - Stencil original paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide stencil original paper which can inhibit deterioration of image quality of a print image even when carrying out plate making by a plate making system using a laser beam. <P>SOLUTION: The stencil original paper 1 includes: a resin film 2; a laser beam intercept layer 3 which is arranged on one surface of the resin film 2 and intercepts a laser beam; and a porous resin layer 4 which is arranged on the surface of the laser beam intercept layer 3 opposite to the resin film 2 and consists of a resin which has a plurality of air holes. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a stencil sheet used for stencil printing.

  Conventionally, a stencil sheet used for a stencil printing plate is known in which an ink-permeable support is laminated on a resin film (see, for example, Patent Document 1). In the stencil sheet, the printing (image) portion of the resin film is perforated in the form of dots in the plate making process, and the printed image is formed on the printing medium by passing the ink through the formed holes.

  As a support in the stencil paper, a mesh-like paper composed of a thin fiber paper, a nonwoven fabric, a woven fabric, etc. composed mainly of natural fibers and synthetic fibers, and a wire made of polyester, etc. A screen is used.

  There is also known a stencil sheet which is not provided with the above-described support and is substantially composed of a single film of a resin film.

  In a stencil sheet using a porous fiber membrane as a support, density unevenness and white spots may occur in a printed image due to the influence of fiber density. Further, with a stencil sheet using a screen as a support, screen eyes and moire may occur in the printed image.

  Further, in the case of a stencil sheet made of a single resin film, ink may be transferred more than necessary to the printing medium during printing, and bleeding may occur in the printed image due to printing dot gain.

  As described above, in the stencil sheet as described above, the image quality of the printed image may be deteriorated due to non-uniform transfer of ink.

  Therefore, a stencil sheet in which a porous resin film is laminated on a resin film has been proposed. In this stencil paper, the porous resin film prevents the ink from being transferred to the print medium more than necessary, and by allowing the ink to pass uniformly, the density unevenness of the printed image is reduced and the deterioration of the image quality is suppressed. can do.

JP 2009-28907 A

  As one of plate making methods for producing a plate for stencil printing, there is a method for making a plate by perforating a resin film of a stencil sheet by irradiating a laser beam.

  In this plate making method using laser light, when a plate is made using a stencil sheet in which a porous resin film is laminated on the above-mentioned resin film, a part of the porous resin film is burned and perforated by the laser light. Damage sometimes occurred. In a plate in which the porous resin film is damaged, ink is transferred more than necessary from the damaged portion to the print medium during printing, resulting in density unevenness in the printed image, which may deteriorate the image quality.

  The present invention has been made in view of the above, and an object of the present invention is to provide a stencil sheet that can suppress a decrease in image quality of a printed image even when a plate making method using a laser beam is used.

  In order to achieve the above object, a stencil sheet according to claim 1 is a stencil sheet that can be used in a stencil making method by irradiating a laser beam, and is disposed on one surface of the resin film and the resin film. A laser beam blocking layer that blocks the laser beam, and a porous resin layer that is disposed on a surface opposite to the resin film side of the laser beam blocking layer and is made of a resin having a plurality of pores. It is characterized by.

  The stencil sheet according to claim 2 further comprises a mesh-shaped screen disposed on a surface of the porous resin layer opposite to the laser light blocking layer side in the stencil sheet according to claim 1, The average pore diameter of the pores in the porous resin layer is smaller than the opening of the screen.

  According to the stencil sheet of the present invention, it is possible to suppress deterioration in the image quality of a printed image even when plate making is performed by a plate making method using laser light.

It is sectional drawing which shows schematic structure of the stencil paper which concerns on the 1st Embodiment of this invention. FIG. 2 is a diagram schematically showing a partially enlarged example of a plate obtained by making the stencil sheet shown in FIG. 1. It is a figure which expands partially and shows typically the other example of the plate obtained by making the stencil paper shown in FIG. 1 partially. It is sectional drawing which shows schematic structure of the stencil paper which concerns on the 2nd Embodiment of this invention. It is the elements on larger scale of the screen used for the stencil paper shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description of the drawings, the same or equivalent parts are denoted by the same or equivalent reference numerals. However, it should be noted that the drawings are schematic and different from the actual ones. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(First embodiment)
FIG. 1 is a cross-sectional view showing a schematic configuration of a stencil sheet according to the first embodiment of the present invention. As shown in FIG. 1, a stencil sheet 1 according to the first embodiment includes a resin (plastic) film 2, a laser light blocking layer 3 disposed on one surface of the resin film 2, and a laser light blocking. The porous resin layer 4 arrange | positioned on the surface on the opposite side to the resin film 2 side of the layer 3 is provided. The stencil sheet 1 can be used in a plate making method in which a plate is made by irradiating a laser beam.

  The resin film 2 is not particularly limited, but polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride, polyamide, polyemulsion, polyvinylidene chloride, epoxy, polycarbonate, polyacetal, Teflon (registered trademark) and the like can be preferably used. From the viewpoint of laser processability, the resin film 2 is preferably a thermoplastic resin film.

  The thickness of the resin film 2 is not particularly limited, but is preferably 4 μm or more from the viewpoint of strength and the like, preferably 300 μm or less from the viewpoint of forming holes during plate making, more preferably 12 to 200 μm, More preferably, it is 38-100 micrometers.

  The resin film 2 may contain an additive for increasing the light absorbency according to the wavelength of laser light described later. For example, for visible light, it is preferable to add a colorant such as black to color the resin film.

  In addition, you may provide the peeling layer which consists of well-known materials, such as a silicone type release agent, a fluorine-type release agent, and a phosphoric acid ester type surfactant, on the surface side to overlap with the printing medium of the resin film 2.

  The laser light blocking layer 3 is a layer formed by including a resin and an inorganic pigment, and absorbs and diffuses laser light irradiated from the resin film 2 side during plate making to the porous resin layer 4. Of the laser beam is blocked. A hole is formed in the laser light blocking layer 3 at the same position as the resin film 2 by irradiation of the laser light, and ink is allowed to pass during printing.

  The thickness of the laser light blocking layer 3 is not particularly limited, but is preferably 5 to 30% of the thickness of the resin film 2. For example, it is about 1 to 20 μm. If the thickness of the laser beam blocking layer 3 is less than 5% of the thickness of the resin film 2, the laser beam blocking effect is lowered, and the porous resin layer 4 may be damaged by the laser beam, which is not preferable. On the other hand, if it exceeds 30%, it is difficult to form holes in the laser light blocking layer 3 at the time of plate making, which obstructs the passage of ink at the time of printing and causes a reduction in image quality of the printed image, which is not preferable.

  The resin material used for forming the laser light blocking layer 3 is not particularly limited, and for example, urethane resins such as polyurethane, vinyl resins such as polyvinyl acetate, acrylic resins, and the like can be used. Two or more resins may be used in combination.

  The inorganic pigment contained in the laser light blocking layer 3 is not particularly limited. For example, titanium oxide, calcium carbonate, silica, or the like can be used. Two or more inorganic pigments may be used in combination.

  The porous resin layer 4 is made of a resin having a large number of pores inside and on the surface thereof. From the viewpoint of ink permeability, it is desirable that the pores have a continuous structure in the thickness direction in the porous resin layer 4.

  The average pore diameter of the pores contained in the porous resin layer 4 is not particularly limited, but is preferably 5 to 30 μm. When the average pore diameter is less than 5 μm, the ink passage property is deteriorated, which is not preferable. On the other hand, if the average pore diameter exceeds 30 μm, the effect of suppressing ink transfer by the porous resin layer 4 is reduced, and the ink is excessively transferred to the printing medium during printing, which is not preferable.

  Although the thickness of the porous resin layer 4 is not specifically limited, It is preferable that it is 5-40 micrometers, and 20-25 micrometers is more preferable. If the thickness of the porous resin layer 4 is less than 5 μm, the porous resin layer 4 may be perforated by laser light during plate making, which is not preferable. On the other hand, if it exceeds 40 μm, it is not preferable because it becomes difficult for ink to pass through the porous resin layer 4.

  The resin material used for forming the porous resin layer 4 is not particularly limited, but polyvinyl acetate, polyvinyl butyral, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, styrene- Vinyl resins such as acrylonitrile copolymers; polyamides such as polybutylene and nylon; cellulose derivatives such as acetylcellulose, acetylbutylcellulose, and acetylpropylcellulose; polyphenylene oxide, (meth) acrylic acid ester, polycarbonate, polyurethane, and the like can be used. Two or more resins may be used in combination.

  It is desirable to add an additive such as a filler to the porous resin layer 4 as necessary in order to adjust the strength, the pore diameter, and the like. Here, the filler is a concept including pigments, powders and fibrous substances. Among them, a needle-like filler is particularly preferable.

  Specific examples include mineral-based needle fillers such as magnesium silicate, sepiolite, potassium titanate, wollastonite, zonotlite, gypsum fiber; non-oxide needle whiskers, oxide whiskers, double oxide needles Artificial mineral needle fillers such as whiskers; plate-like fillers such as mica, glass flakes and talc. As the pigment, not only inorganic pigments but also organic pigments, or organic polymer particles such as polyvinyl acetate, polyvinyl chloride, and polymethyl acrylate; zinc oxide, titanium dioxide, calcium carbonate, and silica can be used.

  The additive amount of such an additive is preferably 5 to 200% with respect to the resin. If it is less than 5%, the bending stiffness is not sufficiently improved by adding an additive. On the other hand, if it exceeds 200%, the adhesion to the laser light blocking layer 3 is lowered, which is not preferable.

  In addition, you may add an antistatic agent, a stick | stick inhibitor, surfactant, antiseptic | preservative, an antifoamer, etc. to the porous resin layer 4 suitably.

  The stencil sheet 1 described above is produced, for example, as follows.

  First, a laser light blocking layer forming paste is prepared by kneading the above-described resin for forming a laser light blocking layer such as polyurethane, an inorganic pigment such as titanium oxide, and an organic solvent. The paste is applied onto the resin film 2 with a bar coater or the like to form a coating film, and the coating film is dried to evaporate the organic solvent, thereby forming the laser light blocking layer 3. Drying of the coating film may be natural drying at room temperature or may be dried by heating with a dryer or the like.

  On the other hand, a coating liquid for forming a porous resin layer is prepared. First, the porous resin layer-forming resin such as polyvinyl butyral described above is dissolved in a solvent containing a solvent or an emulsifier while stirring. At this time, the filler described above may be added. A non-solvent or a non-solvent containing an emulsifier is dropped into the resulting solution. Thereby, the coating liquid for porous resin layer formation which consists of W / O type | mold (water-in-oil type) emulsion which contains resin for porous resin layer formation in an oil phase is obtained.

  The above-mentioned solvent and non-solvent have a relationship of being completely separated into two layers when they are mixed, for example, ethyl acetate and water, toluene and water, and the like.

  As the emulsifier, polyoxyethylene and its derivatives, sorbitan derivatives, ether-modified silicone oils and the like can be used. Two or more emulsifiers may be used.

  The coating liquid for forming the porous resin layer obtained as described above is applied onto the laser light blocking layer 3 with an applicator or the like to form a coating film, and this coating film is heated in an oven or the like to be dried. Let Thereby, the porous resin layer 4 in which the water portion of the W / O type emulsion becomes pores in the resin is formed. The stencil sheet 1 is obtained as described above.

  FIG. 2 is a diagram schematically showing an example of a partially made stencil sheet 1 partially enlarged. At the time of plate making, the stencil sheet 1 is irradiated with laser light from the resin film 2 side (the upper side in FIG. 2).

  When the laser beam is irradiated, the printed (image) portions of the resin film 2 and the laser beam blocking layer 3 are melted and perforated into dots. At this time, the laser light blocking layer 3 prevents the laser light from reaching the porous resin layer 4 and suppresses the generated heat from being transmitted to the porous resin layer 4. Damage is prevented.

  As a result, as shown in FIG. 2, the stencil sheet 1 is formed with holes 5 penetrating the resin film 2 and the laser light blocking layer 3, and the porous resin layer 4 is hardly damaged. In addition, the hole 5 becomes a taper shape in which a diameter becomes small toward the inside of the stencil paper 1 from the surface of the resin film 2 (the upper surface in the drawing in FIG. 2).

  The laser source used for the plate making is not particularly limited, and various lasers having arbitrary beam wavelengths such as solid lasers such as ruby laser and YAG laser; gas lasers such as carbon dioxide laser and argon ion laser; excimer lasers and dye lasers. Available.

  A specific laser device is not particularly limited, and a known digital image signal input method, laser beam operation method, and the like can be used.

  The laser oscillation mode is preferably a pulse wave rather than a continuous wave because a fine processing is easy, and a pulse wave oscillation laser is preferably used.

  From the viewpoint of workability, the laser output is preferably 0.1 to 500 W, and more preferably 1 to 200 W.

  In addition, irradiation conditions such as pulse width (irradiation time per pulse), pulse period, number of pulses (shots), and scanning speed may be appropriately set and modulated so that the holes 5 can be formed according to a desired printing pattern. There is no particular limitation.

  The wavelength of the laser light is not particularly limited, but it is determined by the length of the wavelength whether non-thermal processing or thermal processing becomes dominant. That is, a laser beam having a short wavelength, such as an ultraviolet laser, excites each molecule of the resin film 2 at the irradiation site and scatters them (laser ablation or laser sputtering) to form the holes 5. Becomes dominant. According to this non-thermal processing, fine holes 5 can be formed in a desired shape. On the other hand, in the case of an infrared laser having a long wavelength, the thermal element is large and thermal processing becomes dominant.

  In the present embodiment, the wavelength of the laser light can be subjected to thermal processing in addition to the non-thermal processing due to the photochemical effect, that is, 400 nm to 10.6 μm (10600 nm) accompanied by heat generation is preferable. When the wavelength of the laser beam is not less than the visible light region, not only a chemical reaction but also a thermal reaction is caused to the resin film 2. As a result, a part of the resin film 2 is thermally melted, and a raised portion (not shown) can be formed on the periphery of the hole 5. The bulge around the hole 5 formed on the surface of the resin film 2 (the side overlapping with the printing medium) prevents the ink from protruding from the hole 5 during printing, and forms a sharper blur-free pattern. be able to.

  On the other hand, if the thermal effect of the laser beam is too great, the resin film 2 is excessively melted or shrunk and the shape of the holes 5 is disturbed. As a result, depending on the fineness of the printed pattern, the reproducibility may be lowered. is there. Further, excessive melting or shrinkage of the resin film 2 in the laser light irradiation part affects the entire film 2, and as a result, the plate is shrunk and deformed, the flatness of the plate is lowered, and the print pattern reproducibility is reduced. May decrease.

  Considering these points, the laser beam in the visible light region of 400 nm to 830 nm can be used in a balanced manner by taking full advantage of both the fineness of the chemical reaction and the ridge formation caused by the thermal reaction. More preferably, is used.

  The size of the hole 5 can be arbitrarily changed by changing the energy density of the laser beam and / or the number of irradiation pulses. The diameter of the hole 5 on the surface of the resin film 2 is, for example, about 30 to 200 μm.

  When printing is performed, the resin film 2 surface side of the stencil sheet 1 that has been made is overlapped on a printing medium such as paper, and ink is supplied from the surface side of the porous resin layer 4 (the lower side in the drawing in FIG. 2). The supplied ink passes through the porous resin layer 4 and the ink that has passed through the holes 5 is transferred to the print medium, whereby a print image is formed on the print medium.

  At this time, when the ink passes through the porous resin layer 4, the ink is uniformly dispersed and transferred to the printing medium, so that a printed image without density unevenness can be obtained.

  The type of ink used for printing is not particularly limited. In addition to various stencil printing inks (screen inks) such as emulsion, oiliness, and water, printing such as etching resist ink, solder resist ink, plating resist ink, and marking ink. Substrate ink and conductive ink for electronic precision parts can also be used. Their specific composition is not particularly limited.

  The viscosity of the ink is not particularly limited, but is preferably in the range of 0.01 to 100 Pa · s from the viewpoint of holding the ink on the plate and passing through the holes 5, and is 0.1 to 50 Pa · s. The range is more preferable, and the range of 0.5 to 30 Pa · s is more preferable. Here, the viscosity is a value measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.) at a temperature of 23 ° C. and a shear rate of 10 rpm.

  The type of printing medium (printed material or media) is not particularly limited, and any paper, cloth, leather, plastic film, metal product, wood product, rubber product, ceramic product (ceramics, glass, enamel), etc. Can be selected. Further, the shape of the printing medium is not limited, and the stencil sheet 1 has flexibility, so that it can be printed well even on a curved printing medium.

  The apparatus used for printing is not particularly limited, and for example, printing can be performed by winding a plate around a printing drum of a known rotary stencil printing apparatus and supplying ink from the inside of the printing drum.

  As described above, according to the first embodiment, since the laser light blocking layer 3 is provided between the resin film 2 and the porous resin layer 4, the porous resin layer 4 is damaged by the laser light during plate making. Can be prevented. As a result, the ink can be uniformly dispersed and transferred to the printing medium without impairing the function of the porous resin layer 4, thereby suppressing the occurrence of density unevenness in the printed image and suppressing the deterioration of the image quality. it can.

  In the plate making process, as shown in FIG. 3, the groove 6 may be formed in the resin film 2 by half etching, and the hole 5 may be formed in the region of the groove 6. The groove 6 is formed so as to have a shape in which a desired print pattern is projected.

  When printing is performed using a plate as shown in FIG. 3, ink supplied from the surface side of the porous resin layer 4 and passing through the porous resin layer 4 passes through the holes 5 and fills the grooves 6. Then, the ink filled in the groove 6 is transferred to the print medium, and a pattern in which the shape of the groove 6 is projected is printed.

  In the plate as shown in FIG. 2, holes 5 (dots) are formed corresponding to the print pattern, and the series of holes 5 corresponds to the print pattern. However, in the plate as shown in FIG. The shape corresponds to the print pattern.

(Second Embodiment)
FIG. 4 is a cross-sectional view showing a schematic configuration of a stencil sheet according to the second embodiment of the present invention. As shown in FIG. 4, the stencil sheet 1A according to the second embodiment is different from the stencil sheet 1 of the first embodiment shown in FIG. It is the structure which added the screen 7 arrange | positioned on the surface on the opposite side.

  The screen 7 is formed in a mesh shape by woven a wire made of polyester or the like vertically and horizontally, and is adhered to the porous resin layer 4 with an adhesive such as acrylic or polyurethane.

  The opening of the screen 7 is not particularly limited, but the average pore diameter of the pores in the porous resin layer 4 is preferably smaller than the opening of the screen 7. As described above, since the preferable range of the average pore diameter of the porous resin layer 4 is 5 to 30 μm, the opening of the screen 7 is preferably larger than 30 μm.

  Here, the opening of the screen 7 indicates an interval S between adjacent wires 8 in the screen 7 as shown in FIG. If the opening of the screen 7 is less than 30 μm, the ink permeability from the screen 7 to the porous resin layer 4 is deteriorated, and a desired density may not be obtained in the printed image.

  The stencil sheet 1A is made in the same manner as the stencil sheet 1 of the first embodiment. During printing, ink is supplied from the surface side of the screen 7, the supplied ink passes through the screen 7 and the porous resin layer 4, and the ink that has passed through the holes 5 is transferred to the print medium, thereby printing on the print medium. An image is formed.

  As described above, in the stencil sheet 1A of the second embodiment, since the screen 7 is provided, the durability of the plate can be improved. For this reason, the stencil sheet 1A can be suitably used for a screen printing method for printing by pressing a plate with a squeegee.

  Further, by providing the screen 7, the ink film thickness transferred to the print medium can be increased. Furthermore, by changing the type of screen used (diameter of the wire, etc.), the ink film thickness can be changed and the density of the printed image can be changed.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

(1) Production of stencil sheet <Example 1>
Polyurethane, titanium oxide, and cyclohexanone and isophorone as organic solvents were prepared in the ratios shown in Table 1, respectively, and these were kneaded by a Hoovermarler to prepare a paste for forming a laser light blocking layer. In Tables 1 and 2 below, “parts” represents parts by weight.

  Also, polyvinyl acetal resin (Sekisui Chemical Co., Ltd., ESREC KS-1), talc (Nihon Talc Co., Ltd. Microace LG), and sorbitan fatty acid ester (Nikko Chemicals Co., Ltd. SO-15) Then, a modified silicone oil (KF6012 manufactured by Shin-Etsu Chemical Co., Ltd.) and an acrylic polymer O / W emulsion (Joncry-711 manufactured by Johnson Polymer Co., Ltd.) are dissolved in ethyl acetate while stirring with a dissolver. Water (HEC (hydroxyethylcellulose) 1% solution) was dropped therein to prepare a coating solution for forming a porous resin layer. The ratio of each component is as shown in Table 2.

  The above laser light blocking layer forming paste is coated on a resin film made of polyester (Lumirror X30 manufactured by Toray Industries, Inc., biaxially stretched polyethylene terephthalate, film thickness 75 μm) to form a coating film, A laser light blocking layer having a thickness of 10 μm was formed by drying at room temperature for about half a day.

Thereafter, the coating liquid for forming the porous resin layer is applied onto the laser light blocking layer with an applicator or the like to form a coating film, heated in an oven at 60 ° C. for 10 minutes and dried to obtain a thickness. A 20 μm porous resin layer was formed. As a result, a stencil sheet composed of a resin film, a laser beam blocking layer, and a porous resin layer was obtained.

<Comparative Examples 1 and 2>
A coating solution for forming a porous resin layer similar to that of Example 1 is applied onto a resin film (Lumirror manufactured by Toray Industries, Inc.) with an applicator or the like to form a coating film, and heated in an oven at 60 ° C. for 10 minutes. And dried. This obtained the stencil paper of the comparative example 1 which consists of a resin film and a porous resin layer. In Comparative Example 2, the same resin film as that used in Example 1 (Lumilar manufactured by Toray Industries, Inc.) was used as it was as a stencil paper.

<Examples 2 and 3>
A screen was laminated with an adhesive on the porous resin layer of the stencil sheet as in Example 1. In Example 2, Screen # 420 (Monofilament Screen (Tetron) TNo. 420 S type manufactured by Murakami Co., Ltd.) having a mesh number of 420 and an opening of 33 μm was used. In Example 3, a screen having a mesh number of 100 and an opening of 200 μm was used. # 100 (Murakami Monofilament Screen (Tetron) TNo. 100 S type) was used. The number of meshes of the screen is the number of wires contained in one inch.

<Comparative Examples 3 and 4>
On the porous resin layer of the same stencil paper as in Comparative Example 1, the screen # 420 in Comparative Example 3 and the screen # 100 in Comparative Example 4 were laminated.

<Comparative Examples 5 and 6>
On the same resin film as that used in Example 1, the screen # 420 in the comparative example 5 and the screen # 100 in the comparative example 6 were laminated.

(2) Platemaking Laser output 4.2 W, scan using green laser (LP-G050 (Nd: YVO ₄ , λ = 532 nm) manufactured by SUNX Co., Ltd.) for the stencil sheets of each Example and each Comparative Example. A plate for solid printing was prepared by laser processing under conditions of a speed of 50 mm / s, a pulse period of 25 μm, and a number of pulses (shots) of 50 times.

(3) Printing <Example 1, Comparative Examples 1 and 2>
A plate is wound around a printing drum of a rotary stencil printing apparatus (Risograph (registered trademark) RZ970 manufactured by Riso Kagaku Kogyo Co., Ltd.) and an emulsion ink (RISO ink Z type HD manufactured by Riso Kagaku Kogyo Co., Ltd.) is used. The paper was printed on plain paper under appropriate printing conditions.

<Examples 2 and 3, Comparative Examples 3 to 6>
The plate was adhered and fixed to a screen printing frame to obtain a screen plate. Emulsion ink (RISO ink Z type HD manufactured by Riso Kagaku Kogyo Co., Ltd.) was supplied onto the screen of this screen plate, and printed on plain paper by hand printing using a squeegee.

(4) Evaluation of printed matter Density unevenness of images printed in each example and each comparative example was visually evaluated. The case where density unevenness was not recognized was A, the case where density unevenness was conspicuous was E, and evaluation was made in five stages from A to E depending on the degree of density unevenness.

The composition of the stencil sheet and the evaluation results of the printed matter in Examples 1 to 3 and Comparative Examples 1 to 6 are collectively shown in Tables 3 and 4.

  In Comparative Examples 1, 3, and 4 having a porous resin layer, density unevenness was reduced as compared with Comparative Examples 2, 5, and 6 having no porous resin layer. This indicates that the ink transfer is made uniform by the porous resin layer. On the other hand, in Examples 1 to 3 in which a laser light blocking layer was provided between the resin film and the porous resin layer, compared to Comparative Examples 1, 3, and 4 that have a porous resin layer but no laser light blocking layer. Further, density unevenness was reduced.

  This shows the effect of the laser light blocking layer suppressing damage to the porous resin layer during plate making. This function was exhibited, and density unevenness of the printed matter was suppressed.

1,1A Stencil paper 2 Resin film 3 Laser light blocking layer 4 Porous resin layer 7 Screen

Claims (2)

It is a stencil sheet that can be used in a plate making method that makes a plate by irradiating a laser beam,
A resin film;
A laser light blocking layer disposed on one surface of the resin film and blocking laser light;
A stencil sheet comprising: a porous resin layer made of a resin having a plurality of pores disposed on a surface opposite to the resin film side of the laser light blocking layer. Further comprising a mesh-like screen disposed on the surface of the porous resin layer opposite to the laser light blocking layer side;
2. The stencil sheet according to claim 1, wherein an average pore diameter of pores in the porous resin layer is smaller than an opening of the screen.

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