Multi-layer flexible hose, useful for the compressed air for brake systems of the high power vehicles, comprises a polyamide outer layer, optionally an intermediate layer and an inner layer of polymers with specific flexural moduli

摘要

Multi-layer flexible hose for compressed air, comprises a polyamide outer layer, optionally an intermediate layer of a polymer having a flexural modulus of less than 1500 MPa, and an inner layer of a polymer having a flexural modulus of greater than 1100 MPa, where inner layer is contact with compressed air. Multi-layer flexible hose for compressed air comprises a polyamide outer layer, optionally an intermediate layer of a polymer having a flexural modulus of less than 1500 MPa and an inner layer of a polymer having a flexural modulus of greater than 1100 MPa, where inner layer is contact with compressed air. The polyamide is polyamide-11, polyamide-12 (PA-12), a polyamide (A) of formula XY1/Z or 6Y2/Z or a semi-aromatic polyamide (B1) of formula X2/Y4Ar. X : 6-10C aliphatic diamine; Y1 : 10-14C aliphatic carboxylic diacid; Y2 : 15-20C aliphatic carboxylic diacid; Z : lactam, alpha -omega -amino carboxylic acid or X1Y3; X1 : aliphatic diamine; Y3 : aliphatic carboxylic diacid, where the ratio of Z to the sum of X, Y1 and Z or the sum of six, Y2 and Z is 0-15 wt.%; Ar : aromatic carboxylic diacid; Y4 : 8-20C aliphatic diamine; and X2 : NH 2-(CH 2) 1 0-COOH, lactam-12 or Y4, diamine condensed with an 8-20C aliphatic diacid or diamine with isophthalic acid.