Stencil sheet

• US 6,357,347 B1
• Filed: 06/23/2000
• Issued: 03/19/2002
• Est. Priority Date: 06/25/1999
• Status: Expired due to Term

• Current Assignee: Risco Kagaku Corporation
• Original Assignee: RISO Kagaku Corporation
• Inventors: Yoshida, Kenji
• Primary Examiner(s): Funk, Stephen R.
• Application Number:
  US09/599,744
• Time in Patent Office: 634 Days
• Field of Search: 101/128.21, 101/128.4, 428/195
• US Class Current: 101/128.21
• CPC Class Codes: B41N 1/24 Stencils; Stencil materials; Carriers therefor stencilling apparatus for office or other commercial use B41L13/00
• CPC Class Codes: B41N 1/245 characterised by the thermo-perforable polymeric film heat absorbing means or release coating therefor
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]

Abstract

Stencil sheets which are inhibited from extension when printing of a large number of copies and from getting creases so that originals can be faithfully reproduced and sharp prints can be obtained are described. A stencil sheet can include a laminate of a thermoplastic resin film and a porous support mainly compose of synthetic fibers, and have a wet tensile strength in the longitudinal direction of 200 gf/cm or more, preferably 300 gf/cm or more and a breaking strength under shear in the longitudinal direction of 400 gf/cm² or more, preferably 600 gf/cm² or more. The thermoplastic resin film can have a thickness of 0.1-10 μm.

Claims

1. A stencil sheet comprising a laminate of a thermoplastic resin film and a porous support composed of synthetic fibers, wherein said stencil sheet has a wet tensile strength in the longitudinal direction of 200 gf/cm or more and a breaking strength under shear in the longitudinal of 400 gf/cm² or more.

2. A stencil sheet according to claim 1, in which said thermoplastic resin film has a thickness of 0.1-10 μ

m.

3. A stencil sheet according to claim 1, in which said thermoplastic resin film has a thickness of 0.1-5 μ

m.

4. A stencil sheet according to claim 1, in which said thermoplastic resin film has a thickness of 0.1-3 μ

m.

5. A stencil sheet according to claim 1, in which said wet tensile strength is 300 gf/cm or more.

6. A stencil sheet according to claim 1, in which said breaking strength under shear is 600 gf/cm² or more.

7. A stencil sheet according to claim 1, in which said porous support comprises a nonwoven fabric and the nonwoven fabric is heat-bonded to said thermoplastic resin film.

8. A stencil sheet comprising a thermoplastic resin film and a porous support consisting essentially of synthetic fibers, wherein said stencil sheet has a wet tensile strength in the longitudinal direction of at least 300 cf/cm and a breaking strength under shear in the longitudinal direction of at least 600 cf/cm².

9. A stencil sheet according to claim 8, in which said thermoplastic resin film has a thickness of 0.1-10 μ

m.

10. A stencil sheet according to claim 8, in which said thermoplastic resin film has a thickness of 0.1-5 μ

m.

11. A stencil sheet according to claim 8, in which said thermoplastic resin film has a thickness of 0.1-3 μ

m.

12. A stencil sheet according to claim 8, wherein the synthetic fibers in said porous support have an average fiber diameter of 2-15 μ

m.

13. A stencil sheet according to claim 8, wherein said synthetic fibers in said porous support have a basis weight of 2 to 30 g/m².

14. A stencil sheet according to claim 8, wherein said synthetic fibers in said porous support have a basis weight of 5 to 15 g/m².

15. A stencil sheet according to claim 8, wherein said thermoplastic resin film comprises a polyester film.

16. A stencil sheet according to claim 15, wherein said porous support and said thermoplastic resin film are integrally co-stretched while being heat bonded.

17. A stencil sheet according to claim 8, wherein said porous support comprises a non-woven fabric, which non-woven fabric is heat-bonded to said thermoplastic resin film.

18. A stencil sheet comprising a laminate of a thermoplastic resin film and a porous support of fibers, wherein said stencil sheet has a wet tensile strength in the longitudinal direction of 200 gf/cm or more and a breaking strength under shear in the longitudinal of 400 gf/cm² or more.

19. A stencil sheet according to claim 18, wherein said stencil sheet is obtained by preparing an unstretched thermoplastic resin film, placing said porous support on one side of said unstretched thermoplastic resin film, heat-contact bonding them together, and co-stretching the heat-contact-bonded thermoplastic resin film and porous support.

20. A stencil sheet according to claim 18, wherein said stencil sheet is obtained by preparing a biaxially stretched thermoplastic resin film, and using another resin to adhere one side of said biaxially stretched thermoplastic resin film to said porous support.