Injection molded body having excellent barrier property

Abstract

The present invention relates to a multilayer injection molded article comprising a layer of a barrier resin composition including (A) 10 to 70% by mass of a polyamide resin including a diamine constitutional unit 70 mol % or more of which is derived from m-xylylenediamine and a dicarboxylic acid constitutional unit 70 mol % or more of which is derived from a dicarboxylic acid containing a C 4 to C 20 α,ω-linear aliphatic dicarboxylic acid and isophthalic acid at a molar ratio of from 30:70 to 100:0, (B) 90 to 30% by mass of a modified polyolefin, and the like; a multilayer injection molded article including a layer of a barrier resin composition including (A) 50 to 90% by mass of the above polyamide resin, (B) 2 to 45% by mass of the modified polyolefin and (D) 2 to 45% by mass of a m-xylylene group-free polyamide; and an injection molded article including (A) 10 to 60% by mass of the polyamide resin and (E) 40 to 90% by mass of a polyolefin wherein at least a part of the polyamide (A) is dispersed in a layered state. These molded articles are excellent in barrier property.

1 . An injection molded article with a multilayer structure comprising at least one layer of a barrier resin composition comprising (A) 10 to 70% by mass of a polyamide resin comprising a diamine unit 70 mol % or more of which is one or more m-xylylenediamine units and a dicarboxylic acid unit 70 mol % or more of which is one or more dicarboxylic acid units containing a C 4  to C 20  α,ω-linear aliphatic dicarboxylic acid and isophthalic acid at a molar ratio of from 30:70 to 100:0; (B) 90 to 30% by mass of a modified polyolefin; and (C) 0 to 50% by mass of a polyolefin. 
     
     
         2 . An injection molded article with a multilayer structure comprising at least one layer of a barrier resin composition comprising (A) 50 to 90% by mass of a polyamide resin comprising a diamine unit 70 mol % or more of which is one or more m-xylylenediamine units and a dicarboxylic acid unit 70 mol % or more of which is one or more a dicarboxylic acid units containing a C 4  to C 20  α,ω-linear aliphatic dicarboxylic acid and isophthalic acid at a molar ratio of from 30:70 to 100:0; (B) 2 to 45% by mass of a modified polyolefin; and (D) 2 to 45% by mass of a m-xylylene group-free polyamide. 
     
     
         3 . An injection molded article comprising (A) 10 to 60% by mass of a polyamide resin comprising a diamine unit 70 mol % or more of which is one or more m-xylylenediamine units and a dicarboxylic acid unit 70 mol % or more of which is one or more dicarboxylic acid units containing a C 4  to C 20  α,ω-linear aliphatic dicarboxylic acid and isophthalic acid at a molar ratio of from 30:70 to 100:0; and (E) 40 to 90% by mass of a mixed polyolefin comprising (C) 40 to 100% by mass of a polyolefin and (B) 0 to 60% by mass of a modified polyolefin, wherein at least a part of the polyamide resin (A) is dispersed in a layered state. 
     
     
         4 . The injection molded article according to  claim 1 , wherein the polyamide (A) has a relative viscosity of 2.5 or more as measured at 25° C. in 96% by mass concentrated sulfuric acid as a solvent with a concentration of 1 g/100 mL. 
     
     
         5 . The injection molded article according to  claim 1 , wherein the modified polyolefin (B) is obtained by graft-modifying the polyolefin (C) with an unsaturated carboxylic acid or an anhydride thereof. 
     
     
         6 . The injection molded article according to  claim 2 , wherein the m-xylylene group-free polyamide (D) is an aliphatic polyamide selected from the group consisting of nylon-6, nylon-66 and nylon-666. 
     
     
         7 . The injection molded article according to  claim 2 , wherein the m-xylylene group-free polyamide (D) is an aliphatic polyamide having a relative viscosity of less than 5 as measured at 25° C. in 96% by mass concentrated sulfuric acid as a solvent with a concentration of 1 g/100 mL. 
     
     
         8 . The injection molded article according to  claim 1 , wherein the article has a multilayer structure in which the layer of the barrier resin composition is sandwiched between thermoplastic resin layers (F) each made of a polyolefin. 
     
     
         9 . The injection molded article according to  claim 1 , wherein the article is in the form of a multilayer stretched injection molded article obtained by subjecting a multilayer injection molded article to biaxial stretch blow molding. 
     
     
         10 . The injection molded article according to  claim 2 , wherein the polyamide (A) has a relative viscosity of 2.5 or more as measured at 25° C. in 96% by mass concentrated sulfuric acid as a solvent with a concentration of 1 g/100 mL. 
     
     
         11 . The injection molded article according to  claim 2 , wherein the modified polyolefin (B) is obtained by graft-modifying a polyolefin (C) with an unsaturated carboxylic acid or an anhydride thereof. 
     
     
         12 . The injection molded article according to  claim 3 , wherein the modified polyolefin (B) is obtained by graft-modifying the polyolefin (C) with an unsaturated carboxylic acid or an anhydride thereof. 
     
     
         13 . The injection molded article according to  claim 2 , wherein the article has a multilayer structure in which the layer of the barrier resin composition is sandwiched between thermoplastic resin layers (F) each made of a polyolefin. 
     
     
         14 . The injection molded article according to  claim 2 , wherein the article is in the form of a multilayer stretched injection molded article obtained by subjecting a multilayer injection molded article to biaxial stretch blow molding.