Patent ID: 6906165

Claim:
A copolyamide, comprising macromolecular units derived from the following monomers: (I) at least one difunctional monomer represented by the abbreviation AB (II) at least one multifunctional monomer represented by the abbreviation AaBb in which A represents a carboxylic acid function and B represents an amine function, a and b being numbers that satisfy the following relationships: a≧1 b≧1 a+b≧3 (III) at least one multifunctional monomer represented by the abbreviation AcBd in which A represents a carboxylic acid function and B represents an amine function, c and d being numbers that satisfy the following relationships: c≧0 d≧0 c+d≧2, the pair (c,d) being different than the pair (1,1) the monomers (II) and (III) being chosen such that d>c if a>b d<c if a<b the ratio ax + cy ax + cy + bx + dy being between 0.4 and 0.6, in which x represents the number of moles of monomer (II) and y represents the number of moles of monomer (III) the ratio ax + cy + bx + dy ( a + c + b + d ) * ( x + y + 0.9 * z ) is less than 0.05, in which z represents the number of moles of monomer (I).