Patent EA-000642-B1 (EA)
Title: Propylene polymer compositions having improved impact strength
Inventor: WANG HSIEN-CHANG
IPC: C08L23/28
Filed: 1996-06-28
Abstract: 1. A solid, impact-resistant thermoplastic polymer composition having good clarity comprising a melt-mixed blend of: a) a crystalline propylene polymer; b) a copolymer of a C4-C7 isomonoolefin containing from 0.5 to 20 mole% of copolymerized para-alkcylstyrene, said copolymer present in said composition at a level of from about 1 to 35 wt%, based on the polymer content of said composition. 2. The composition of Claim 1 wherein said propylene polymer is selected from the group consisting of polypropylene and copolymers of propylene with up to 20 wt% of a C2 or C4-C8 alpha-monoolefin. 3. The composition of Claim 1 wherein said isomonoolefin is isobutylene and said para-alkylstyrene is para-methylstyrene. 4. The composition of Claim 1 wherein said copolymer is present in said composition at a level of from 5 to 30 wt%. 5. The composition of Claim 1 wherein said copolymer comprises a polymer of isobutylene containing the following aromatic monomer units:   wherein R and R' are independently hydrogen or C1-C4 alkyl and X is a functional group. 6. The composition of Claim 5 wherein the X-containing monomer units comprise from 0.5 to 60 mole % of the total content of said aromatic monomer units present in said copolymer. 7. The composition of Claim 5 wherein X is halogen. 8. The composition of Claim 7 wherein R and R' are each hydrogen and X is bromine present in said copolymer at a level of less than 2.5 wt%. 9. The composition of Claim 8 wherein bromine is present in said copolymer at a level of from 0.05 to 0.75 wt%. 10. The composition of Claim 7 which further contains from 0.5 to 15 wt% of an additive polymer comprising the amide reaction product of: (i) a modified crystalline propylene polymer containing a grafted unsaturated organic compound, said unsaturated organic compound selected from the group consisting of an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride and mixtures thereof; and (ii) a polyfunctional primary amine having one primary amine group and at least one hydroxyl, secondary amine or tertiary amine group. 11. The composition of Claim 10 wherein said propylene polymer is polypropylene. 12. The composition of Claim 10 wherein said unsaturated. organic compound is maleic anhydride. 13. The composition of Claim 10 wherein said primary ammo is selected from the group consisting of 2-(2-amino-ethylamino) ethanol and 1-(2-aminoethyl) piperazine. 14. The composition of Claim 1 wherein said copolymer is present in said composition at a level of from 10 to 25 wt%. 16. The composition of Claim 1 wherein said icopolymer is present in said composition at a level of from 1 to 20 wt%. 16. The composition of Claim 1 wherein said copolymer is present in said composition at a level of from 10 to 20 wt%. 17. A process for preparing a thermoplastic polymer blend comprising: (a) forming a mixture comprising a crystalline propylene polymer and from 1 to 35 wt% of a copolymer of a 04 to C7 isomonoolefin containing 0.6 to 20 mole% of copolymerized para-alkylstyrene; and (b) melt mixing said mixture at a temperature in the range of 150 to 250 degree  C until a uniform blend is obtained. 18. The process of Claim 17 wherein said copolymer comprises a brominated polymer of isobutylene and para-methylstyrene containing bromine at a level of from 0.05 to 0.75 wt%, 19. The process of Claim 18 wherein said mixture further contains from 0.5 to 15 wt% of an additive polymer comprising the amide reaction product of: (i) a modified crystalline propylene polymer containing an unsaturated organic compound grafted along the polymer chain, said unsaturated compound selected from the group consisting of an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride and mixtures thereof; and (ii) a polyfunctional primary amine having one primary amine group and at least one hydroxy, secondary amine or tertiary amine group. 20. A shaped article prepared by melt mixing the composition of Claim 1, and forming and cooling the molten mixture into the shape of the article.