Polyamide resin composition

Abstract

The present invention relates to a polyamide resin composition comprising polyamide (X) comprising a diamine unit containing 70 mol % or more of a metaxylylenediamine unit and a dicarboxylic acid unit and an alkali compound (A), wherein the following equations (1) to (3) are satisfied: 0.03≦ P <0.32  (1) 2.2≦ M <26.1  (2) 5< M/P ≦200  (3) wherein P represents a mole concentration (μmol/g) of a phosphorus atom contained per g of the polyamide resin composition; and M represents a sum (μmol/g) of values obtained by multiplying a mole concentration of an alkali metal atom and a mole concentration of an alkaline earth metal atom each contained per g of the polyamide resin composition by valencies thereof respectively.

1 . A polyamide resin composition comprising a polyamide (X) comprising a diamine unit comprising 70 mol % or more of a metaxylylenediamine unit and a dicarboxylic acid unit and an alkali compound (A), wherein the following equations (1) to (3) are satisfied:
   0.03≦ P< 0.32  (1);
     2.2≦ M≦ 26.1  (2); and
     5< M/P≦ 200  (3),
   wherein:   P represents a mole concentration (μmol/g) of a phosphorus atom contained per g of the polyamide resin composition; and   M represents a sum (μmol/g) of values obtained by multiplying a mole concentration of an alkali metal atom and a mole concentration of an alkaline earth metal atom each contained per g of the polyamide resin composition by valencies thereof respectively.   
     
     
         2 . The polyamide resin composition according to  claim 1 , wherein the alkali compound (A) is a carboxylate having 10 or less carbon atoms of an alkali metal. 
     
     
         3 . The polyamide resin composition according to  claim 1 , wherein the polyamide (X) is polyamide comprising a diamine unit comprising 70 mol % or more of a metaxylylenediamine unit and a dicarboxylic acid unit comprising 70 mol % or more of an adipic acid unit. 
     
     
         4 . The polyamide resin composition according to  claim 1 , wherein the polyamide (X) is polyamide comprising a diamine unit comprising 70 mol % or more of a metaxylylenediamine unit and a dicarboxylic acid unit comprising 70 to 99 mol % of an adipic acid unit and 1 to 30 mol % of an isophthalic acid unit. 
     
     
         5 . The polyamide resin composition according to  claim 1 , wherein the polyamide (X) is polyamide comprising a diamine unit comprising 70 mol % or more of a metaxylylenediamine unit and a dicarboxylic acid unit comprising 70 mol % or more of a sebacic acid unit. 
     
     
         6 . A process for producing the polyamide resin composition according to  claim 1 , the process comprising:
 (a) reacting a diamine comprising 70 mol % or more of metaxylylenediamine and a dicarboxylic acid by polycondensation in the presence of a phosphorus atom-containing compound (B) to obtain the polyamide (X); and   (b) adding the an alkali compound (A) the polyamide (X) to form a polyamide resin composition.   
     
     
         7 . The process according to  claim 6 , wherein in the polycondensation (a) occurs in the presence of the phosphorus atom-containing compound (B) and an alkali metal compound (C). 
     
     
         8 . The process according to  claim 6 , wherein the reacting (b) comprises:
 (b1) molting and kneading 90 to 99 parts by mass of the polyamide (X) and 10 to 1 parts by mass of the alkali compound (A) with an extrusion equipment to obtain a polyamide master batch (Y); and   (b2) molting and kneading 0.5 to 20 parts by mass of the polyamide master batch (Y) and 99.5 to 80 parts by mass of the polyamide (X).   
     
     
         9 . The process according to any of  claim 8 , wherein:
 the polyamide master batch (Y) is such that a sum of values obtained by multiplying a mole concentration of an alkali metal atom and a mole concentration of an alkaline earth metal atom each contained per g of the polyamide master batch (Y) by valencies thereof, respectively, is 12 μmol/g or more and 900 μmol/g or less; and   the alkali compound (A) satisfies the following conditions (i) and (ii):
 (i) the alkali compound (A) is a carbonate, a hydrogencarbonate or a carboxylate having 10 or less carbon atoms of an alkali metal or an alkaline earth metal; and 
 (ii) a melting temperature Tm of the alkali compound (A) is not higher than a melt-kneading temperature K. 
   
     
     
         10 . A polyamide master batch suitable for the process according to  claim 8 ,
 wherein:   the polyamide master batch is obtained by molting and kneading 90 to 99 parts by mass of the polyamide (X) comprising a diamine unit containing 70 mol % or more of a metaxylylenediamine unit and a dicarboxylic acid unit and 10 to 1 parts by mass of an alkali compound (A) in the presence of the phosphorus atom-containing compound (B) and an alkali metal compound (C);   the polyamide master batch is such that a sum of values obtained by multiplying a mole concentration of an alkali metal atom and a mole concentration of an alkaline earth metal atom each contained per g of the master batch by valencies thereof, respectively, is 12 μmol/g or more and 900 μmol/g or less; and   the alkali compound (A) satisfies the following conditions (i) and (ii):
 the alkali compound (A) is a carbonate, a hydrogencarbonate or a carboxylate having 10 or less carbon atoms of an alkali metal or an alkaline earth metal; and 
 (ii) a melting temperature Tm of the alkali compound (A) is not higher than a melt-kneading temperature K. 
   
     
     
         11 . A multilayer molded article, comprising:
 an outermost layer;   an innermost layer; and   a gas-barrier layer between the outermost layer and the innermost layer,   wherein:   the outermost layer and the innermost layer are formed from a polyester resin comprising a dicarboxylic acid unit comprising 80 mol % or more of a terephthalic acid unit and a diol unit comprising 80 mol % or more of an ethylene glycol unit; and   the gas-barrier layer is formed from the polyamide resin composition according to  claim 1 .   
     
     
         12 . The multilayer molded article according to  claim 11 , which is a multilayer bottle obtained by blow-molding a multilayer preform by a hot parison method or a cold parison method. 
     
     
         13 . The polyamide resin composition according to  claim 2 , wherein the polyamide (X) is polyamide comprising a diamine unit comprising 70 mol % or more of a metaxylylenediamine unit and a dicarboxylic acid unit comprising 70 mol % or more of an adipic acid unit. 
     
     
         14 . The polyamide resin composition according to  claim 2 , wherein the polyamide (X) is polyamide comprising a diamine unit comprising 70 mol % or more of a metaxylylenediamine unit and a dicarboxylic acid unit comprising 70 to 99 mol % of an adipic acid unit and 1 to 30 mol % of an isophthalic acid unit. 
     
     
         15 . The polyamide resin composition according to  claim 2 , wherein the polyamide (X) is polyamide comprising a diamine unit comprising 70 mol % or more of a metaxylylenediamine unit and a dicarboxylic acid unit comprising 70 mol % or more of a sebacic acid unit. 
     
     
         16 . The process according to  claim 7 , wherein the reacting (b) comprises:
 (b1) molting and kneading 90 to 99 parts by mass of the polyamide (X) and 10 to 1 parts by mass of the alkali compound (A) with an extrusion equipment to obtain a polyamide master batch (Y); and   (b2) molting and kneading 0.5 to 20 parts by mass of the polyamide master batch (Y) and 99.5 to 80 parts by mass of the polyamide (X).   
     
     
         17 . The process according to any of  claim 16 , wherein:
 the polyamide master batch (Y) is such that a sum of values obtained by multiplying a mole concentration of an alkali metal atom and a mole concentration of an alkaline earth metal atom each contained per g of the polyamide master batch (Y) by valencies thereof, respectively, is 12 μmol/g or more and 900 μmol/g or less; and   the alkali compound (A) satisfies the following conditions (i) and (ii):
 (i) the alkali compound (A) is a carbonate, a hydrogencarbonate or a carboxylate having 10 or less carbon atoms of an alkali metal or an alkaline earth metal; and 
 (ii) a melting temperature Tm of the alkali compound (A) is not higher than a melt-kneading temperature K. 
   
     
     
         18 . A polyamide master batch suitable for the process according to  claim 9 ,
 wherein:   the polyamide master batch is obtained by molting and kneading 90 to 99 parts by mass of the polyamide (X) comprising a diamine unit containing 70 mol % or more of a metaxylylenediamine unit and a dicarboxylic acid unit and 10 to 1 parts by mass of an alkali compound (A) in the presence of the phosphorus atom-containing compound (B) and an alkali metal compound (C);   the polyamide master batch is such that a sum of values obtained by multiplying a mole concentration of an alkali metal atom and a mole concentration of an alkaline earth metal atom each contained per g of the master batch by valencies thereof, respectively, is 12 μmol/g or more and 900 μmol/g or less; and   the alkali compound (A) satisfies the following conditions (i) and (ii):
 (i) the alkali compound (A) is a carbonate, a hydrogencarbonate or a carboxylate having 10 or less carbon atoms of an alkali metal or an alkaline earth metal; and 
 (ii) a melting temperature Tm of the alkali compound (A) is not higher than a melt-kneading temperature K.