Gasket

Patent metadata

Field	Value
Publication number	US-10088050-B2
Application number	US-201514790229-A
Country	US
Kind code	B2
Filing date	Jul 2, 2015
Priority date	Jul 31, 2014
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

Abstract

The present invention provides a gasket excellent in properties such as sliding properties and resistance to liquid leakage. The present invention relates to a gasket whose sliding surface includes annular projections, the gasket having polymer chains immobilized on at least part of its surface, the annular projections including a first projection that is nearest to a top face, and a bottom side projection that is farthest from the top face, the first projection and/or the bottom side projection having an annular flat portion with a width of 0.1 mm or more.

First claim

The invention claimed is:

1. A gasket whose sliding surface comprises annular projections, the gasket having polymer chains immobilized on at least part of its surface,
the annular projections including a first projection that is nearest to a top face, and a bottom side projection that is farthest from the top face,
at least one of the first projection or the bottom side projection having an annular flat portion with a width of 0.1 mm or more,
wherein a curved surface portion is provided on top and bottom sides of the first projection, and
wherein the curved surface portion on the bottom side has a greater curvature than the curved surface portion on the top side.

2. The gasket according to claim 1 ,
wherein the bottom side projection has an annular flat portion which is wider than that of the first projection.

3. The gasket according to claim 1 ,
wherein the bottom side projection has an annular flat portion with a width of 0.4 mm or more.

4. The gasket according to claim 1 ,
wherein the gasket comprises three or more annular projections,
the annular projections include an intermediate projection between the first projection and the bottom side projection, and
the intermediate projection has a smaller outer diameter than the first projection and the bottom side projection.

5. The gasket according to claim 4 ,
wherein the outer diameter of the intermediate projection is 96 to 99.5% of the outer diameter of the first projection.

6. The gasket according to claim 1 ,
wherein the curved surface portion on the bottom side has a curvature of 0.4 to 2.0.

7. The gasket according to claim 1 ,
wherein the polymer chains are immobilized by a surface modification method comprising:
step 1 of forming polymerization initiation points A on a surface of a gasket base material; and
step 2 of radically polymerizing a monomer, starting from the polymerization initiation points A, to grow polymer chains.

8. The gasket according to claim 7 ,
wherein the surface modification method comprises
step 3 of further extending the polymer chains grown in the step 2, or immobilizing different polymer chains onto the polymer chains grown in the step 2.

9. The gasket according to claim 7 ,
wherein the step 1 comprises adsorbing a photopolymerization initiator A onto a surface of a gasket base material, optionally followed by irradiation with LED light having a wavelength of 300 to 450 nm, to form polymerization initiation points A from the photopolymerization initiator A on the surface.

10. The gasket according to claim 7 ,
wherein the step 2 comprises radically polymerizing a monomer, starting from the polymerization initiation points A, by irradiation with LED light having a wavelength of 300 to 450 nm to grow polymer chains.

11. The gasket according to claim 1 ,
wherein the polymer chains are immobilized by a surface modification method comprising
step I of radically polymerizing a monomer in the presence of a photopolymerization initiator A on a surface of a gasket base material to grow polymer chains.

12. The gasket according to claim 11 ,
wherein the surface modification method comprises
step II of further extending the polymer chains grown in the step I, or immobilizing different polymer chains onto the polymer chains grown in the step I.

13. The gasket according to claim 11 ,
wherein the step I comprises radically polymerizing a monomer by irradiation with LED light having a wavelength of 300 to 450 nm to grow polymer chains.

14. The gasket according to claim 1 ,
wherein a length of the polymer chain is 10 to 50000 nm.

Assignees

• Sumitomo Rubber Ind

Inventors

• Minagawa Yasuhisa

Classifications

• F16J15/108

  Special methods for making a non-metallic packing · CPC title

• F16J1/003

  with integral sealing lips · CPC title

• F16J15/102 Primary

  characterised by material · CPC title

• A61M5/31513 Primary

  Piston constructions to improve sealing or sliding · CPC title

• F16J15/104

  characterised by structure · CPC title