Combined seals, compositions, and methods of making the same
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 3 , less than 0.70 g/cm 3 , and less than 0.60 g/cm 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.).
1. A combined sealing member comprising:
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 3 , less than 0.70 g/cm 3 , and less than 0.60 g/cm 3 ,
wherein 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.).
2. The combined sealing member of claim 1 , wherein the dense silane-crosslinked polyolefin elastomer comprises a first polyolefin having a density less than 0.86 g/cm 3 , a second polyolefin having a percent crystallinity less than 40%, a silane crosslinker, a grafting initiator, and a non-metal condensation catalyst,
wherein the microdense silane-crosslinked polyolefin elastomer comprises a first polyolefin having a density less than 0.86 g/cm 3 , a second polyolefin having a percent crystallinity less than 40%, a silane crosslinker, a grafting initiator, a condensation catalyst and a microencapsulated foaming agent, and
further wherein the dynamic silane-crosslinked polyolefin elastomer comprises a first polyolefin having a density less than 0.86 g/cm 3 , a second polyolefin having a percent crystallinity less than 40%, a silane crosslinker, a grafting initiator, a condensation catalyst and a foaming agent.
3. The combined sealing member of claim 1 , wherein the compression set is from about 15.0% to about 35.0%, as measured according to ASTM D 395 (22 hrs @ 70° C.).
4. The combined sealing member of claim 1 , wherein the density is from about 0.50 g/cm 3 to about 0.89 g/cm 3 .
5. The combined sealing member of claim 1 , wherein the silane-crosslinked polyolefin elastomer exhibits a crystallinity of from about 5% to about 25%.
6. The combined sealing member of claim 1 , wherein the silane-crosslinked polyolefin elastomer exhibits a glass transition temperature of from about −75° C. to about −25° C.
7. The combined sealing member of claim 1 , wherein the composition is a thermoset, but exhibits thermoplastic properties during processing.
8. The combined sealing member of claim 1 , wherein the sealing member exhibits a weathering color difference of from about 0.25 ΔE to about 2.0 ΔE, as measured according to ASTM D2244.
9. The combined sealing member of claim 1 , further comprising:
a coloring agent.
10. A combined sealing member comprising:
a composition comprising a first and a second polyolefin elastomer,
wherein the first elastomer comprises a microdense silane-crosslinked polyolefin elastomer having a density of less than 0.70 g/cm 3 ,
wherein the second elastomer comprises a dense silane-crosslinked polyolefin elastomer having a density of less than 0.90 g/cm 3 or a dynamic silane-crosslinked polyolefin elastomer having a density of less than 0.60 g/cm 3 , and
further wherein 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.).
11. The combined sealing member of claim 10 , wherein the compression set is from about 15.0% to about 35.0%, as measured according to ASTM D 395 (22 hrs @ 70° C.).
12. The combined sealing member of claim 10 , wherein the density is from about 0.50 g/cm 3 to about 0.89 g/cm 3 .
13. The combined sealing member of claim 10 , wherein the silane-crosslinked polyolefin elastomer exhibits a crystallinity of from about 5% to about 25%.
14. The combined sealing member of claim 10 , wherein the silane-crosslinked polyolefin elastomer exhibits a glass transition temperature of from about −75° C. to about −25° C.
15. A combined sealing member comprising:
a composition comprising a first and a second polyolefin elastomer,
wherein the first elastomer comprises a dense silane-crosslinked polyolefin elastomer having a density of less than 0.90 g/cm 3 ,
wherein the second elastomer comprises a dynamic silane-crosslinked polyolefin elastomer having a density of less than 0.60 g/cm 3 , and
further wherein 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.).
16. The combined sealing member of claim 15 , wherein the compression set is from about 15.0% to about 35.0%, as measured according to ASTM D 395 (22 hrs @ 70° C.).
17. The combined sealing member of claim 15 , wherein the density is from about 0.50 g/cm 3 to about 0.89 g/cm 3 .
18. The combined sealing member of claim 15 , wherein the silane-crosslinked polyolefin elastomer exhibits a crystallinity of from about 5% to about 25%.
19. The combined sealing member of claim 15 , wherein the silane-crosslinked polyolefin elastomer exhibits a glass transition temperature of from about −75° C. to about −25° C.
20. The combined sealing member of claim 15 , further comprising:
a coloring agent.