Patent ID: 7954528

Claim:
A thermoplastic elastomer composition comprising (A) at least one halogenated isobutylene-containing elastomer; and (B) at least one nylon resin having a melting point of about 170° C. to about 230° C.; wherein: (1) said at least one halogenated isobutylene-containing elastomer is present as a dispersed phase of small vulcanized or partially vulcanized particles in a continuous phase of said nylon; (2) said halogenated isobutylene-containing elastomer particles have been formed by dynamic vulcanization; and (3) said halogenated isobutylene-containing elastomer particles comprising greater than about 60 volume % of the volume of said elastomer and said resin being obtained by a process comprising the steps of: (1) mixing halogenated elastomer-containing composition (A′) comprising a first fraction of the total amount of halogenated elastomer in said thermoplastic elastomer composition and further comprising a cure system for said first elastomer fraction; and thermoplastic nylon resin (B) under suitable dynamic vulcanization conditions of time, temperature and shear to form composition (C); (2) mixing composition (C) and halogenated elastomer-containing composition (D), said composition (D) comprising a second fraction of the total amount of halogenated elastomer in said thermoplastic elastomer composition and further comprising a cure system for said second elastomer fraction; under suitable dynamic vulcanization conditions of time, temperature and shear to form composition (E); (3) if the sum of said first and second fractions of halogenated elastomer is less than the total amount of halogenated elastomer in said thermoplastic elastomer composition, mixing composition (E) and halogenated elastomer-containing composition (F), said composition (F) comprising a third fraction of the total amount of halogenated elastomer in said thermoplastic elastomer composition and further comprising a cure system for said third elastomer fraction; under suitable dynamic vulcanization conditions of time, temperature and shear to form composition (G); wherein the step of dynamically vulcanizing a fractional additional amount of halogenated elastomer in the presence of the dynamically vulcanized composition of the preceding step is repeated as many times as necessary in order to obtain the total amount of halogenated elastomer in said thermoplastic elastomer composition; and wherein each said dynamic vulcanization conditions at each step are sufficient to effect a cure state in said elastomer particles of at least about 50% of the maximum cure state for said elastomer and cure system and wherein said dynamic vulcanization time period is equal to or less than about the characteristic residence time of said mixer.