Use of a reinforced thermoplastic composition

Use of a fiber-reinforced thermoplastic composition for obtaining a molded article having a reduced warpage, wherein the composition comprises:

• from 30 to 70% by weight of an amorphous polyamide matrix by total weight of the composition;
• and,
• from 30 to 70% by weight of glass fibers with a circular cross-section by total weight of the composition;
• and,
• optionally additives;
• wherein the amorphous polyamide matrix comprises at least one amorphous polyamide and at least one aliphatic semi-crystalline polyamide;
• wherein the fiber-reinforced thermoplastic composition has a melt viscosity of at most 1,300 Pa·s, when measured at a shear rate of 110 s−1 at 260° C. according to the ISO11443:2014 standard;
• wherein the weight ratio between the amorphous polyamide and the aliphatic semi-crystalline polyamide in the amorphous polyamide matrix is from 60:40 to 90:10;
• wherein the amorphous polyamide is selected from the group consisting of homopolyamides of formula X1Y1, copolyamides of formula Z1/X1Y1 and/or copolyamides of formula X0Y0/X1Y1;
• wherein the unit X1 is derived from a cycloaliphatic diamine monomer having from 8 to 18carbons or a mixture of at least two of these monomers thereof;
• wherein the unit Y1 is derived from a linear aliphatic diacid monomer having from 4 to 36 carbons or a mixture of at least two of these monomers thereof;
• or wherein the unit Y1is derived or an aromatic diacid having from 6 to 18 carbons or a mixture of at least two of these monomers thereof;
• wherein the unit Z1, if present, is derived from an amino acid monomer having from 9 to 18 carbons or a lactam monomer having from 6 to 18 carbons;
• wherein the unit X0, if present, is derived from a linear aliphatic diamine monomer having from 4 to 18 carbons or a mixture of at least two of these monomers thereof;
• wherein the unit Y0, if present, is derived from a linear aliphatic diacid monomer having from 4 to 36 carbons or a mixture of at least two of these monomers thereof;
• wherein the aliphatic semi-crystalline polyamide is selected from the group consisting of polyamides of formula Z2 and/or polyamides of formula X2Y2;
• wherein the unit Z2, if present, is derived from an amino acid having from 9 to 18 carbons;
• or a lactam having from 6 to 18 carbons;
• wherein the unit X2, if present, is derived from an aliphatic diamine monomer from 4 to 18 carbons, or mixtures thereof;
• and wherein the unit Y2, if present, is derived from a linear aliphatic diacid monomer having from 4 to 36 carbons, or mixtures thereof.