The present invention relates to an amorphous or microcrystalline copolyamide (A) containing at least the following monomers: (a) at least one cycloaliphatic diamine; (b) 0.25 to 4.4 mol % of at least one dimeric fatty acid; and (c) 12 to 49.75 mol % of at least one aromatic dicarboxylic acid selected from the group consisting of isophthalic acid, terephthalic acid and naphthalenedicarboxylic acid, and (d) 0 to 37.75 mol % of at least one aliphatic dicarboxylic acid; where the molar proportion of isophthalic acid is at least equal to the molar proportion of terephthalic acid, and where the monomers (b), (c) and optionally (d) add up to 50 mol % and the molar proportions of all the monomers present in the copolyamide (A) add up to 100 mol %. The invention further relates to moulding compounds comprising the copolyamide (A), to mouldings made therefrom and to the use thereof.