Resin composition of good long-run workability, comprising ethylene-vinyl alcohol copolymer

Abstract

The present invention relates to a resin composition having an ethylene-vinyl alcohol copolymer (EVOH) component and a multi-layered structure containing the resin composition.

1 - 20 . (canceled) 
     
     
         21 . Pellets of a resin composition comprising an ethylene-vinyl alcohol copolymer, wherein when the resin composition is heated in a nitrogen atmosphere at 220° C., its melt flow rate (MFR) at 230° C. under a load of 10.9 kg shows a minimum value within 10 hours after the start of heating it, and shows a maximum value (MFRmax) within 100 hours after showing its minimum value,
 that it satisfies the following formula (1):
   0.5≦MFRmax/MFR0≦45  (1)
 
 wherein
 MFRmax indicates the maximum value of melt flow rate (at 230° C. under a load of 10.9 kg) of the resin composition heated in a nitrogen atmosphere at 220° C.; 
 MFR0 indicates melt flow rate (at 230° C. under a load of 10.9 kg) of the resin composition not heated; 
 
 
 that it contains, based on the weight of the resin composition:
 from 50 to 500 ppm of a carboxylic acid (a2) having a molecular weight of smaller than 75, 
 from 50 to 500 ppm, in terms of the metal element, of an alkali metal salt (B), 
 from 10 to 120 ppm, in terms of the metal element, of an alkaline earth metal salt (C), 
 from 10 to 200 ppm, in terms of the phosphate radical, of a phosphate compound (D), and 
 from 50 to 2000 ppm, in terms of the boron element, of a boron compound (E), and 
 from 0.005 to 1 part by weight, relative to 100 parts by weight of the ethylene-vinyl alcohol copolymer therein, of a lubricant, wherein 
 
 said pellets have from 0.005 to 0.5 parts by weight, relative to 100 parts by weight of the resin composition, of the lubricant adhered on the outer surfaces thereof, and 
 wherein the lubricant is a bis-amide of a fatty acid having at least 10 carbon atoms. 
 
     
     
         22 . The resin composition as claimed in  claim 21 , wherein the carboxylic acid (a2) having a molecular weight of smaller than 75 is an acetic acid. 
     
     
         23 . The resin composition as claimed in  claim 21 , which satisfies the following formula (4):
   1 ≦[B (μmol/g)+ C (μmol/g)]/[ D (μmol/g)+( a 2)(μmol/g)]≦15  (4)
   wherein (a2) indicates the content (μmol/g) of the carboxylic acid (a2) having a molecular weight of smaller than 75 in the resin composition per the unit weight of the composition; B indicates the content (μmol/g, in terms of the metal element) of the alkali metal salt (B) in the resin composition per the unit weight of the composition; C indicates the   content (μmol/g, in terms of the metal element) of the alkaline earth metal salt (C) in the resin composition per the unit weight of the composition; D indicates the content (μmol/g, in terms of the phosphate radical) of the phosphate compound (D) in the resin composition per the unit weight of the composition.   
     
     
         24 . The resin composition as claimed in  claim 21 , wherein the bis-amide of a fatty acid having at least 10 carbon atoms is an ethylenebis-stearic acid amide.