Sealing material

Patent metadata

Field	Value
Publication number	US-9403957-B2
Application number	US-201013384140-A
Country	US
Kind code	B2
Filing date	Jul 14, 2010
Priority date	Jul 14, 2009
Publication date	Aug 2, 2016
Grant date	Aug 2, 2016

Abstract

A sealing material is provided, which maintains excellent sealing property for a long period of time. The sealing material of the invention is characterized by being prepared by vulcanizing and foaming a mixture containing a rubber component containing a copolymer rubber of ethylene, an α-olefin having 3 or more carbon atoms, and a non-conjugated diene, a vulcanizing agent, and a blowing agent, wherein the mixture contains a thermoplastic resin having a melting point of 80° C. or less.

First claim

The invention claimed is:

1. A sealing material prepared by vulcanizing and foaming a mixture comprising ethylene-propylene-diene copolymer rubber as a rubber component, a vulcanizing agent, a blowing agent, a vulcanization promoting auxiliary, and a dehydrating agent, wherein the mixture comprises a thermoplastic resin having a melting point of 80° C. or less, stearic acid as the vulcanization promoting auxiliary, and calcium oxide as the dehydrating agent, the sealing material having a density in the range of 90 to 150 kg/m 3 measured in accordance with JIS K 7222,
wherein the thermoplastic resin is an ethylene-vinyl acetate copolymer, the ethylene-vinyl acetate copolymer is contained in the range of 5 to 40 parts by weight, based on 100 parts by weight of the rubber component, the ethylene-vinyl acetate copolymer has a melt flow rate in the range of 18 to 2500 g/10 min., and the ethylene-vinyl acetate copolymer has a vinyl acetate content in the range of 25 to 35 wt %,
wherein the vulcanizing agent is contained in the range of 1 to 30 parts by weight, based on 100 parts by weight of the rubber component, and
wherein the sealing material has an expansion ratio in the range of 5 to 30 and a cell number in the range of 50 to 150/25 mm, and the sealing material has a closed cell structure.

2. The sealing material as claimed in claim 1 , wherein the vulcanizing agent consists essentially of sulfur.

3. The sealing material as claimed in claim 1 , wherein the blowing agent is azodicarboxylic amide.

4. The sealing material as claimed in claim 1 , wherein the sealing material has a density in the range of 90 to 110 kg/m 3 measured in accordance with JIS K 7222.

5. The sealing material as claimed in claim 1 , wherein the sealing material comprises a film of ethylene-vinyl acetate copolymer resin (EVA) on the surface thereof.

6. The sealing material as claimed in claim 1 , wherein a melt flow rate of the ethylene-vinyl acetate copolymer is in the range of 18 to 500 g/10 min.

7. The sealing material as claimed in claim 4 , wherein the sealing material has a density in the range of 102 to 110 kg/m 3 .

8. The sealing material as claimed in claim 1 , wherein the sealing material has a water cut-off property that is maintained upon exposure to heat.

9. The sealing material as claimed in claim 1 , wherein the vulcanizing agent consists of sulfur.

Assignees

• Otsuka Masaru
• Seki Katsuya
• Yamamoto Tomohiro
• Takeda Youhei
• Bridgestone Corp

Inventors

• Otsuka Masaru
• Seki Katsuya
• Yamamoto Tomohiro
• Takeda Youhei

Classifications

• C09K2200/0622

  Polyvinylalcohols, polyvinylacetates · CPC title

• C08J2323/16

  Ethene-propene or ethene-propene-diene copolymers · CPC title

• C08J3/24

  Crosslinking, e.g. vulcanising, of macromolecules (mechanical aspects B29C35/00; crosslinking agents C08K) · CPC title

• C08L23/16

  Ethylene-propylene or ethylene-propylene-diene copolymers · CPC title

• C08J9/103 Primary

  Azodicarbonamide · CPC title