Low-compression force metal gaskets
View Patent ↗A low-compression force metal gasket includes a coating layer containing a polymer material on at least a sealing surface of the gasket, and the coating layer satisfies the following conditions (1) to (3): (1) the layer comprises a resin, a rubber or a mixture thereof having an oxygen gas permeability coefficient at 25° C. of 10×10 −12 to 0.1×10 −12 (m 2 /s); (2) when the layer is compression deformed, the storage elastic modulus (E′) at 200° C. is in the range of 1.0×10 7 to 1.0×10 2 Pa; and (3) the coating layer has a thickness of 1 to 40 μm. The gasket provides a high seal at a low clamping force.
1. A low-compression force metal gasket including a coating layer containing a fluororubber, a fluororesin or a mixture thereof on at least a sealing surface of the gasket, the coating layer satisfying the following conditions (1) to (3):
(1) the layer comprises a resin, a rubber or a mixture thereof having an oxygen gas permeability coefficient at 25 ° C. of 10×10 −12 to 0.1×10 −12 (m 2 /s);
(2) when the layer is compression deformed, the storage elastic modulus (E′) at 200° C. is in the range of 1.0×10 7 to 1.0×10 2 Pa; and
(3) the coating layer has a thickness of 1 to 40 μm.
2. The gasket according to claim 1 , which is softened such that the sealing surfaces are plastically deformed easily.
3. The gasket according to claim 2 , wherein the resin or rubber comprises main structural units derived from ethylene tetrafluoride and containing a perfluoroalkyl group wherein the alkyl group has 2 to 16 carbon atoms.
4. The gasket according to claim 2 , which is a metal C-ring gasket or a spring-energized metal C-ring gasket.
5. The gasket according to claim 1 , wherein the resin or rubber comprises main structural units derived from ethylene tetrafluoride and containing a perfluoroalkyl group wherein the alkyl group has 2 to 16 carbon atoms.
6. The gasket according to claim 5 , which is a metal C-ring gasket or a spring-energized metal C-ring gasket.
7. The gasket according to claim 1 , which is a metal C-ring gasket or a spring-energized metal C-ring gasket.