Resin composition and multilayer structure using same

Abstract

A resin composition, comprising: apolyolefin (A); a saponified ethylene-vinyl acetate copolymer (EVOH) (B) having an ethylene content of 20 to 65 mol % and having a degree of saponification of vinyl acetate units of 96% or more; a higher fatty acid metal salt (C) having 8 to 22 carbon atoms; a conjugated polyene compound (D) having a boiling point of 20° C. or higher; an ethylene-vinyl acetate copolymer (E); and a saponified ethylene-vinyl acetate copolymer (F) having an ethylene content of 68 to 98 mol % and having a degree of saponification of vinyl acetate units of 200 or more, wherein the mass ratio (A:B) of the polyolefin (A) and the EVOH (B) is 60:40 to 99.9:0.1, the amount of the higher fatty acid metal salts (C) is in the range of 0.0001 to 10 parts by mass per 100 parts by mass of the total of the polyolefin (A) and the EVOH (B), the amount of conjugated polyene compound (D) is in the range of 0.000001 to 1 part by mass, and the total amount of the ethylene-vinyl acetate copolymer (E) and the saponified ethylene-vinyl acetate copolymer (F) is 0.3 part by mass or more. This enables improvement of poor appearance of a molded article caused by insufficient dispersion of the EVOH (B) at the time of melt molding a resin composition comprising the polyolefin (A) and the EVOH (B).

1 . A resin composition, comprising:
 a polyolefin (A);   a saponified ethylene-vinyl acetate copolymer (B) having an ethylene content of 20 to 65 mol % and a degree of saponification of vinyl acetate units of 96% or more;   a higher fatty acid metal salt (C) having 8 to 22 carbon atoms;   a conjugated polyene compound (D) having a boiling point of 20° C. or higher;   an ethylene-vinyl acetate copolymer (E); and   a saponified ethylene-vinyl acetate copolymer (F) having an ethylene content of 68 to 98 mol % and having a degree of saponification of vinyl acetate units of 20% or more;   wherein:   a mass ratio (A:B) of the polyolefin (A) to the saponified ethylene-vinyl acetate copolymer (B) is from 60:40 to 99.9:0.1;   an amount of the higher fatty acid metal salt (C) is from 0.0001 to 10 parts by mass per 100 parts by mass of a total of the polyolefin (A) and the saponified ethylene-vinyl acetate copolymer (B);   an amount of the conjugated polyene compound (D) is from 0.000001 to 1 part by mass per 100 parts by mass of the total of the polyolefin (A) and the saponified ethylene-vinyl acetate copolymer (B); and   a total amount of the ethylene-vinyl acetate copolymer (E) and the saponified ethylene-vinyl acetate copolymer (F) is at least 0.3 parts by mass per 100 parts by mass of the total of the polyolefin (A) and the saponified ethylene-vinyl acetate copolymer (B).   
     
     
         2 . The resin composition according to  claim 1 , wherein a mass ratio (E:F) of the ethylene-vinyl acetate copolymer (E) to the saponified ethylene-vinyl acetate copolymer (F) is from 99.9:0.1 to 70.0:30.0. 
     
     
         3 . The resin composition according to  claim 1 , wherein the composition is prepared by:
 preparing a master batch by melt-blending the higher fatty acid metal salt (C), the ethylene-vinyl acetate copolymer (E), and the saponified ethylene-vinyl acetate copolymer (F); and   melt-blending the master batch, the polyolefin (A), the saponified ethylene-vinyl acetate copolymer (B), and the conjugated polyene compound (D).   
     
     
         4 . The resin composition according to  claim 1 , wherein the composition is prepared by:
 preparing a master batch by melt-blending the polyolefin (A), the higher fatty acid metal salt (C), the ethylene-vinyl acetate copolymer (E), and the saponified ethylene-vinyl acetate copolymer (F); and   melt-blending the master batch, the polyolefin (A), the saponified ethylene-vinyl acetate copolymer (B), and the conjugated polyene compound (D).   
     
     
         5 . The resin composition according to  claim 3 , wherein:
 analysis of the master batch by nuclear magnetic resonance spectroscopy ( 1 H-NMR) shows a signal strength ratio (Ja:Jb) of from 99.5:0.5 to 70.0:30.0;   Ja is a signal derived from hydrogen atoms bonded to carbon atoms to which acetoxy groups are bonded; and   Jb is a signal derived from hydrogen atoms bonded to carbon atoms to which hydroxyl groups are bonded.   
     
     
         6 . The resin composition according to  claim 1 , further comprising a hydrotalcite (G) in an amount of from 0.0001 to 10 parts by mass per 100 parts by mass of the total of the polyolefin (A) and the saponified ethylene-vinyl acetate copolymer (B). 
     
     
         7 . A multilayer structure, comprising:
 a layer made of the resin composition according to  claim 1 ; and   a layer made of a saponified ethylene-vinyl acetate copolymer having an ethylene content of 20 to 65 mol % and having a degree of saponification of vinyl acetate units of 96% or more.   
     
     
         8 . The resin composition according to  claim 4 , wherein:
 analysis of the master batch by nuclear magnetic resonance spectroscopy ( 1 H-NMR) shows a signal strength ratio (Ja:Jb) of from 99.5:0.5 to 70.0:30.0;   Ja is a signal derived from hydrogen atoms bonded to carbon atoms to which acetoxy groups are bonded; and   Jb is a signal derived from hydrogen atoms bonded to carbon atoms to which hydroxyl groups are bonded.