Oriented thermoplastic elastomer film and process for producing the same

Abstract

An oriented thermoplastic elastomer film having reduced permeability and improved fatigue resistance comprising a dynamically vulcanized polymer blend of (A) a halogenated isobutylene elastomer and (B) polyamide, the film is produced by C casting or blowing the above polymer blend under the condition such that a shear rate at a die lip for casting or blowing is regulated to control the molecular arrangement in the film, whereby the planar birefringemence (PBR) of the resultant film becomes greater or equal to 0.002 and a production process of the same.

1 . An oriented thermoplastic elastomer film having reduced permeability and improved fatigue resistance comprising a dynamically vulcanized polymer blend of (A) a halogenated isobutylene elastomer and (B) polyamide, the film is produced by casting or blowing the above polymer blend under the condition such that a shear rate at a die lip for casting or blowing is regulated to control the molecular arrangement in the film, whereby the planar birefringemence (PBR) of the resultant film becomes greater or equal to 0.002.  
   
   
       2 . An oriented thermoplastic elastomer film as claimed in  claim 1 , wherein the amount of the halogenated isobutylene elastomer is 95 to 25 parts by weight and the amount of the polyamide is 5 to 75 parts by weight.  
   
   
       3 . An oriented thermoplastic elastomer film as claimed in  claim 1  wherein the halogenated isobutylene elastomer is brominated poly(isobutylene-co-p-methylstyrene.  
   
   
       4 . An oriented thermoplastic elastomer film as claimed in  claim 1 , wherein the polyamide is at least one member selected from the group consisting of Nylon 6, Nylon 66 Nylon 11, Nylon 69, Nylon 12, Nylon 610, Nylon 612, Nylon 46, Nylon MXD6, Nylon 6/66 and the copolymers thereof, and the blends thereof.