Elastomer composition and medical container stopper formed by molding same

Abstract

The elastomer composition of the present invention comprises a thermoplastic elastomer composition which contains 20 to 80% by weight of component (A), 1 to 25% by weight of component (B), and 1 to 70% by weight of component (C): Component (A): at least one block copolymer selected from: a block copolymer having a polymer block derived from a vinyl aromatic compound and a polymer block derived from at least one selected from a conjugated diene and isobutylene; and a block copolymer obtained by hydrogenating the block copolymer; Component (B): a polypropylene resin containing component (B1): a modified polypropylene obtained by graft-modifying a polypropylene resin with a diene compound; and Component (C): a softener for hydrocarbon rubbers.

1 . A elastomer composition comprising a thermoplastic elastomer composition comprising 20 to 80% by weight of component (A), 1 to 25% by weight of component (B), and 1 to 70% by weight of component (C) with respect to a total amount of the following component (A), component (B), and component (C):
 Component (A): at least one block copolymer selected from: a block copolymer having a polymer block derived from a vinyl aromatic compound and a polymer block derived from at least one selected from a conjugated diene and isobutylene; and a block copolymer obtained by hydrogenating the block copolymer;   Component (B): a polypropylene resin containing component (B1) below
 Component (B1): a modified polypropylene obtained by graft-modifying a polypropylene resin with a diene compound; and 
   Component (C): a softener for hydrocarbon rubbers.   
     
     
         2 . The elastomer composition according to  claim 1 , wherein the diene compound of the component (B1) is a conjugated diene compound. 
     
     
         3 . The elastomer composition according to  claim 2 , wherein the conjugated diene compound of the component (B1) is isoprene. 
     
     
         4 . The elastomer composition according to  claim 1 , wherein the component (B1) has a melt flow rate (ISO 1133 (230° C., load 2.16 kg)) of 0.1 to 200 g/10 min. 
     
     
         5 . The elastomer composition according to  claim 1 , wherein a weight average molecular weight (Mw) of the component (A) is 100,000 to 500,000. 
     
     
         6 . The elastomer composition according to  claim 1 , wherein the elastomer composition has durometer hardness A (ISO 7619-1) of 10 to 40. 
     
     
         7 . The elastomer composition according to  claim 1 , wherein the elastomer composition is an elastomer composition for a medical container stopper. 
     
     
         8 . A medical container stopper formed from the elastomer composition according to  claim 1 . 
     
     
         9 . The medical container stopper according to  claim 8 , wherein the medical container stopper is a medical rubber stopper.