Thermoplastic elastomer composition having moderate cure state
View Patent ↗A thermoplastic elastomer composition comprising a dynamically vulcanized blend of (A) a partially cured halogenated isobutylene elastomer and (B) a polyamide, wherein a tensile modulus at 100% elongation of the halogenated isobutylene elastomer dispersed in the polyamide matrix is less than 0.60 MPa.
1. A thermoplastic elastomer (TPE) composition comprising a dynamically vulcanized blend of a partially cured halogenated isobutylene elastomer and a polyamide where the tensile modulus of the elastomer dispersed in the polyamide is less than 0.56 MPa.
2. The TPE composition of claim 1 wherein the elastomer comprises a brominated copolymer of isobutylene and para-alkyl styrene.
3. The TPE composition of claim 1 , wherein the elastomer comprises a copolymer of isobutylene and para-methyl styrene.
4. The TPE of claim 1 , wherein the polyamide comprises one or more of Nylon 6, Nylon 66, Nylon 11, Nylon 69, Nylon 12, Nylon 610, Nylon 612, Nylon 46, Nylon MXD6, Nylon 6/66.
5. The TPE composition of claim 1 , wherein the polyamide has a softening point of from 160 to 230° C.
6. The TPE composition of claim 1 , wherein the polyamide is present at 5 to 75 parts by weight and the elastomer is present at 95 to 25 parts by weight.
7. The TPE composition of claim 1 , wherein the elastomer has a number average molecular weight of at least about 50,000.
8. The TPE composition of claim 1 , wherein the elastomer has an Mw/Mn of less than about 6.
9. The TPE composition of claim 1 , wherein the elastomer has a Mooney viscosity (1+4) at 125° C. as measured by ASTM D 1646-99 of 25 or more.
10. The TPE composition of claim 1 , wherein the elastomer is a brominated copolymers of isobutylene and para-methylstyrene having 5 to 12 weight % para-methylstyrene, 0.3 to 1.8 mol % brominated para-methylstyrene, and a Mooney viscosity of 30 to 65 (1+4) at 125° C. as measured by ASTM D 1646-99.
11. A process for producing cured thermoplastic elastomer (TPE) composition comprising shear mixing a partially cured halogenated isobutylene elastomer and a polyamide and curing the TPE at a temperature less than 185° C.