Resin composition and medical drug container using same

Abstract

Provided is a resin composition comprising 50 to 80 wt % of a norbornene-based polymer, and 20 to 50 wt % of a hydrogenated styrene-based thermoplastic elastomer, a content of a low-molecular-weight component having a molecular weight of 1000 or less in the resin composition being 3 wt % or less, in which the hydrogenated styrene-based thermoplastic elastomer is an aromatic vinyl-conjugated diene block copolymer having a styrene content of 40 wt % or more, or a block copolymer that includes an aromatic vinyl compound-based polymer block and an isobutylene-based polymer block having a styrene content of 15 wt % or more. Also, a medical drug container that shows very low protein adsorption with the passage of time is produced using such a resin composition.

1 . A resin composition comprising 50 to 80 wt % of a norbornene-based polymer, and 20 to 50 wt % of a hydrogenated styrene-based thermoplastic elastomer, a content of a low-molecular-weight component having a molecular weight of 1000 or less in the resin composition being 3 wt % or less, wherein
 the hydrogenated styrene-based thermoplastic elastomer is an aromatic vinyl-conjugated diene block copolymer having a styrene content of 40 wt % or more, or a block copolymer that includes an aromatic vinyl compound-based polymer block and an isobutylene-based polymer block having a styrene content of 15 wt % or more.   
     
     
         2 . The resin composition according to  claim 1 , wherein the norbornene-based polymer is a hydrogenated norbornene-based ring-opening polymer. 
     
     
         3 . The resin composition according to  claim 1 , wherein the aromatic vinyl-conjugated diene block copolymer having a styrene content of 40 wt % or more is the hydrogenated styrene-based thermoplastic elastomer of at least one hydrogenated styrene-based thermoplastic elastomer selected from a group consisting of a styrene-ethylene/butylene-styrene block copolymer, a styrene-ethylene/propylene-styrene block copolymer, a partially hydrogenated styrene-ethylene/butylene-styrene block copolymer, and a styrene-(ethylene-ethylene/propylene)-styrene block copolymer. 
     
     
         4 . The resin composition according to  claim 3 , wherein the aromatic vinyl-conjugated diene block copolymer having a styrene content of 40 wt % or more is a styrene-ethylene/butylene-styrene block copolymer. 
     
     
         5 . The resin composition according to  claim 1 , wherein the content of a low-molecular-weight component having a molecular weight of 1000 or less in the resin composition has been adjusted to 3 wt % or less using one method, or a plurality of methods, among (I) evaporative removal of a low-molecular-weight component from the norbornene-based polymer, (II) reprecipitation of the norbornene-based polymer using a good solvent and a poor solvent, and (III) preliminary drying of the resin composition before forming. 
     
     
         6 . A medicine container obtained using the resin composition according to  claim 1 . 
     
     
         7 . The medicine container according to  claim 6 , the medicine container being used for a medicine that includes a protein.