USE OF COPOLYAMIDES FOR MANUFACTURING COMPOSITIONS THAT REMAIN RIGID UNDER THE EFFECT OF MOISTURE

摘要

The invention mainly relates to the use of a semi-crystalline copolyamide having the formula A/X1Y, where: A is a repeating unit obtained by polycondensation of at least one C6- to C18-lactam, or at least one C6- to C18-amino acid, or at least one repeating unit XY obtained by polycondensation of at least one linear aliphatic C4- to C18-diamine (X) and at least one aliphatic C6- to C18-dicarboxylic acid (Y); and X1Y is a repeating unit obtained by polycondensation of at least one cycloaliphatic diamine (X1) and at least one aliphatic C6- to C18-dicarboxylic acid (Y), the mass ratio between comonomer A and comonomer X1Y ranging from 60/40 to 90/10, for preparing objects of which the tensile modulus, measured according to ISO 527, does not vary more than 20% between the dry state and the water-saturated state. The invention further relates to a composition comprising 25 to 65% by weight of said semi-crystalline copolyamide, 35 to 75% by weight of reinforcements, 0 to 10% by weight of at least one impact modifier, 0 to 10% by weight of at least one viscosity modulating agent, 0 to 20% by weight of at least one filler, and 0 to 5% by weight of additives. The invention finally relates to a method for manufacturing said composition and to a molded object obtainable from said composition.