Resin composition and multilayered structure

摘要

A resin composition, contains: a thermoplastic polyurethane (A); a thermoplastic polyurethane (B); and an ethylene-vinyl alcohol copolymer (C), wherein an isocyanate group content (mole) in raw materials of the thermoplastic polyurethane (A) is greater than a hydroxyl group content (mole) therein, an isocyanate group content (mole) in raw materials of the thermoplastic polyurethane (B) is nearly equal to a hydroxyl group content (mole) therein, and the thermoplastic polyurethane (B) and the ethylene-vinyl alcohol copolymer (C) have a mass ratio (B/C) of from 70/30 to 99/1 and a content of the thermoplastic polyurethane (A), based on 100 parts by mass of a total of the thermoplastic polyurethane (B) and the ethylene-vinyl alcohol copolymer (C), is from 1 to 30 parts by mass. Thus, a resin composition is provided that contains thermoplastic polyurethanes and an ethylene-vinyl alcohol copolymer and is good in melt shapability.

主权项

1. A resin composition, comprising:
(A) a thermoplastic polyurethane (A), which is a thermoplastic polyurethane obtained by reacting a polyisocyanate, a high molecular weight polyol, and a chain extender, and is a thermoplastic polyurethane in which the high molecular weight polyol comprises polyester polyol or polyether polyol having a number average molecular weight of from 500 to 8000 and the chain extender comprises a low molecular weight polyol having a molecular weight of 300 or less, and satisfies expression (1)
1.02≦PIa/(POHa+CLa)≦1.12  (1) wherein PIa is content (mole) of isocyanate groups in the polyisocyanate, wherein POHa is content (mole) of hydroxyl groups in the high molecular weight polyol, and wherein CLa: content (mole) of hydroxyl groups in the chain extender; (B) a thermoplastic polyurethane (B), which is a thermoplastic polyurethane obtained by reacting a polyisocyanate, a high molecular weight polyol, and a chain extender, and is a thermoplastic polyurethane in which the high molecular weight polyol comprises polyester polyol or polyether polyol having a number average molecular weight of from 500 to 8000 and the chain extender comprises a low molecular weight polyol having a molecular weight of 300 or less, and satisfies expression (2)
PIb/(POHb+CLb)<1.02  (2), wherein PIb is content (mole) of isocyanate groups in the polyisocyanate wherein POHb is content (mole) of hydroxyl groups in the high molecular weight polyol wherein CLb is content (mole) of hydroxyl groups in the chain extender; (C) a ethylene-vinyl alcohol copolymer (C), which is an ethylene-vinyl alcohol copolymer comprising ethylene in a content of from 20 to 60 mol % and having a degree of saponification of 90 mol % or more, wherein the thermoplastic polyurethane (B) and the ethylene-vinyl alcohol copolymer (C) have a mass ratio (B/C) of from 70/30 to 99/1, and wherein a content of the thermoplastic polyurethane (A), based on 100 parts by mass of a total of the thermoplastic polyurethane (B) and the ethylene-vinyl alcohol copolymer (C), is from 1 to 30 parts by mass.