| 主权项 |
1. A composition comprising a blend of:
a) a (co)polyamide a) of type 66 comprising at least 90 mol % of adipic acid and hexamethylenediamine monomer residues, said (co)polyamide a) having an Mn of 8,000 to 14,000 g/mol; b) a (co)polyamide b) of type 6, said (co)polyamide b) comprising at least 90 mol % of caprolactam monomer residues and having an Mn of 25,000 to 30,000 g/mol; and c) 0% to 40% by weight, relative to the total weight of the composition, of reinforcing fillers; and d) optionally, one or more additives; wherein the (co)polyamide a) and the (co)polyamide b) form a polyamide matrix comprising 80% to 95% by weight of the (co)polyamide a) of type 66, relative to the total weight of the polyamide matrix, and 5% to 20% of the (co)polyamide b) of type 6, relative to the total weight of the polyamide matrix; wherein the total weight of the composition is the sum of the weights of the polyamide matrix formed by: the (co)polyamides a) and b), the reinforcing fillers c), and the optional one or more additives d); wherein the ratio of the viscosities in solution, measured according to Standard ISO 307 in formic acid, of the (co)polyamide a) relative to the (co)polyamide b) is between 0.3 and 0.8; said composition having an apparent melt viscosity, in Pa·s, according to the following relationships:
η100≦8(X)+100η1000≦3(X)+90 in which η is the apparent melt viscosity of the polyamide composition measured at a temperature of 275° C.; either at a shear rate of 100 s−1, η100, or at a shear rate of 1000 s−1, η1000; and X corresponds to the proportion by weight of reinforcing fillers, relative to the total weight of the composition; and the apparent melt viscosity is measured according to Standard ISO 11443. |
