A microdense sealing member is provided. The microdense sealing member includes a composition having a foamed silane-crosslinked polyolefin elastomer with a density less than 0.70 g/cm.sup.3. The microdense sealing member can exhibit a compression set of from about 5.0% to about 35.0% measured according to ASTM D 395 (22 hrs @ 70? C.). The foamed silane-crosslinked polyolefin elastomer can be produced from a blend including a first polyolefin having a density less than 0.86 g/cm.sup.3, a second polyolefin having a crystallinity less than 60? C., a silane crosslinker, a grafting initiator, a condensation catalyst, and a microencapsulated foaming agent.

A combined sealing member is provided that includes a composition comprising two or more polyolefin elastomers selected from the group consisting of a dense, a micro-dense and a dynamic silane-crosslinked polyolefin elastomer having a respective density of less than 0.90 g/cm.sup.3, less than 0.70 g/cm.sup.3, and less than 0.60 g/cm.sup.3. The combined sealing member exhibits a compression set of from about 5.0% to about 35.0%, as measured according to ASTM D 395 (22 hrs @ 70? C.).

A sponge sealing member is provided that includes a composition having a silane-crosslinked polyolefin elastomer with a density less than 0.60 g/cm.sup.3. The sponge sealing member can exhibit a compression set of from about 5.0% to about 35.0%, as measured according to ASTM D 395 (22 hrs @ 70? C.). The silane-crosslinked polyolefin elastomer can also include a first polyolefin having a density less than 0.86 g/cm.sup.3, a second polyolefin having a crystallinity less than 40%, a silane crosslinker, a grafting initiator, a condensation catalyst, and a foaming agent.

The invention relates to polyorganosiloxanes with special silicon-containing groups of the general formula (1) as defined herein, a method for preparing said polyorganosiloxanes, and curable compositions comprising at least one said polyorganosiloxane, at least one adhesion promoter, and at least one curing catalyst. The invention also relates to adhesive, sealant, or coating materials comprising the curable composition and the use of the curable composition.

Provided is a rubber composition for sealing material which contains 100 parts by mass of a rubber component, 50 to 140 parts by mass of silica, 1 to 20 parts by mass of a silane coupling agent, and 15 to 35 parts by mass of carbon black. The rubber component is preferably an ethylene-propylene-diene rubber.