Multicomponent thermoset structures
Composite structures are described that include (a) a first polymer structure (e.g., a film or solid component) made of EPDM adhered to (b) a second polymer structure (film or solid component) that is made of a blend of dynamically vulcanized EPDM dispersed in a matrix of a thermoplastic polyolefin polymer. Either the first polymer structure, or both the first and second polymer structures are blended with an effective amount of a semicrystalline random adhesive copolymer.
1. An elastomeric sealing structure comprising: (a) a first polymer structure made of an thermoset EPDM material blended with from 5 to 50 phr of a semicrystalline random copolymer adhered to (b) a second polymer structure made of a blend of a dynamically vulcanized elastomeric material dispersed in a matrix of a thermoplastic polyolefin polymer, wherein said sealing structure is one of extruded profiles or moldings.
2. The composite structure of claim 1 in which the semicrystalline random copolymer is present in the amount of from 15 to 30 phr, based on the EPDM material.
3. The composite structure of claim 1 in which the semicrystalline random copolymer has a crystallinity of from 2% to 65% of the crystallinity of isotactic polypropylene.
4. The composite structure of claim 1 in which the semicrystalline random copolymer includes 70–88 mole % propylene units and alpha olefin units having 2 carbon atoms or from 4 to 10 carbon atoms.
5. The composite structure of claim 1 in which the second polymer structure is made from a blend of dynamically vulcanized EPDM dispersed in a matrix of a propylene polymer.
6. The composite structure of claim 5 in which composite structure has energy at break of adhesion at least 50% greater than the energy at break of adhesion of a composite structure in which the elastomeric material of the first and second polymer structures include EPDM but do not include semicrystalline random copolymer.
7. The composite structure of claim 1 in which the first polymer structure and the second polymer structure are both non-film structures.
8. The sealing structure of claim 1 wherein said structure is for an automobile and is selected from the group consisting of glass run channels, door seals, belt line seals, insulation, roof seals, trunk seals and hood seals.
9. The composite structure of claim 1 in which the second polymer structure (b) also contains from 5 to 50 weight percent of a semicrystalline random copolymer, based on the weight of the thermoplastic polyolefin polymer in (b).
10. The composite structure of claim 9 in which the semicrystalline random copolymer is present in an amount of from 10 to 20 weight percent.
11. The composite structure of claim 9 in which the semicrystalline random copolymer has a crystallinity of from 2% to 65% of the crystallinity of isotactic polypropylene.
12. The composite structure of claim 9 in which the semicrystalline random copolymer includes 70–88 mole % propylene units and alpha olefin units having 2 carbon atoms or from 4 to 10 carbon atoms.
13. The composite structure of claim 9 in which the second polymer structure is made from a blend of dynamically vulcanized EPDM dispersed in a matrix of a propylene polymer.
14. The composite structure of claim 9 in which the elastomeric materials in the first and second polymer structures comprise EPDM, and the composite structure has energy at break of adhesion at least 50% greater than the energy at break of adhesion of a composite structure in which the elastomeric material of the first and second polymer structures include EPDM but in which the second polymer structure does not include semicrystalline random copolymer.