Microporous stencil sheet and application thereof

• US 20030150340A1
• Filed: 02/25/2003
• Published: 08/14/2003
• Est. Priority Date: 06/22/2000
• Status: Active Grant

• Current Assignee: RISO Kagaku Corporation
• Original Assignee: RISO Kagaku Corporation
• Inventors: Yamamoto, Yasuo, Kinoshita, Hideyuki
• Granted Patent: US 6,675,705 B2
• Time in Patent Office: Days
• US Class Current: 101/127
• CPC Class Codes: B41C 1/14 for stencil-printing or silk-screen printing
• CPC Class Codes: B41C 1/147 by imagewise deposition of a liquid, e.g. from an ink jet; Chemical perforation by the hardening or solubilizing of the ink impervious coating or sheet
• CPC Class Codes: B41N 1/24 Stencils; Stencil materials; Carriers therefor stencilling apparatus for office or other commercial use B41L13/00
• CPC Class Codes: Y10T 428/249979 Specified thickness of void-containing component [absolute or relative] or numerical cell dimension
• CPC Class Codes: Y10T 428/249987 With nonvoid component of specified composition

Abstract

A microporous stencil sheet for use in stencil printing and methods for making stencil master using this microporous stencil sheet are disclosed herein. The microporous stencil sheet is for use in stencil printing using a low-viscosity ink with a viscosity ranging from 0.001 to 1 Pa•s, comprises an inelastic resin film and has an air permeability ranging from 1 to 600 seconds and a thickness ranging from 1 to 100 μm. The methods for making stencil master using this microporous stencil sheet comprise the step of closing the micropores of the stencil sheet in a non-printing portion of a desired printed image.

Claims

1. A microporous stencil sheet composed of an inelastic resin film for use in stencil printing, wherein the microporous stencil sheet has an air permeability ranging from 1 to 600 seconds and a thickness ranging from 1 to 100 μ

m and is for use in stencil printing using a low-viscosity ink with a viscosity ranging from 0.001 to 1 Pa•

s.

2. A microporous stencil sheet according to claim 1, wherein the inelastic resin film is a thermoplastic resin film.

3. A microporous stencil sheet according to claim 2, wherein the inelastic resin film is a polyolefin film.

4. A microporous stencil sheet according to claim 1, wherein the micropores of the microporous stencil sheet have a mean pore size ranging from 0.01 to 10 μ

m.

5. A microporous stencil sheet according to claim 1, wherein the microporous stencil sheet has micropores formed by stretching out the inelastic resin film in at least one axial direction.

6. A microporous stencil sheet according to claim 1, wherein the microporous stencil sheet has a photo-thermal conversion substance on the surface or inside of the microporous stencil sheet.

7. A microporous stencil sheet according to claim 1, wherein the microporous stencil sheet has an antistatic agent on the surface or inside of the microporous stencil sheet.

8. A microporous stencil sheet according to claim 1, wherein the microporous stencil sheet has a releasing layer on its surface, the releasing layer comprising a release agent selected from the group consisting of silicone-based release agents, fluorine-based release agents, wax-based release agents, and surfactant-based release agents.

9. A microporous stencil sheet according to claim 8, wherein the releasing layer comprises a release agent containing a silicone phosphate ester as a principal component.

10. A method for making a stencil master using a microporous stencil sheet, the microporous stencil sheet comprising a thermoplastic resin film and having an air permeability ranging from 1 to 600 seconds and a thickness ranging from 1 to 100 μ

m, the method comprising the step of closing, by heat fusion, the micropores of the microporous stencil sheet in a non-printing portion of a desired printed image to form an ink-impermeable portion.

11. A method according to claim 10, wherein the heat fusion is performed by heat generated from a thermal head.

12. A method according to claim 10, wherein the microporous stencil sheet has a photo-thermal conversion substance on the surface or inside of the microporous stencil sheet, and wherein the heat fusion is performed by irradiation with electromagnetic waves.

15. A stencil master obtained by the method for making a stencil master according to claim 10.

13. A method for making a stencil master using a microporous stencil sheet, the microporous stencil sheet having an air permeability ranging from 1 to 600 seconds and a thickness ranging from 1 to 100 μ

m, the method comprising the step of closing the micropores of the microporous stencil sheet in a non-printing portion of a desired printed image by deposition of a resin, wax or both to form an ink-impermeable portion.

14. A method according to claim 13, wherein the resin, wax or both are deposited from a thermal transfer sheet by fusion transfer.

16. A stencil master obtained by the method for making a stencil master according to claim 13.