addition to the polymeric fatty acids the acid component may contain c 4 to c 12 dicarboxylic acids and monocarboxylic acids with up to 20 carbon atoms examples of suitable dicarboxylic acids are maleic acid succinic acid adipic acid azelaic acid sebacic acid dodecane dioic acid glutaric acid suberic acid pimelic acid or aromatic dicarboxylic acids e g terephthalic acid or mixtures of these dicarboxylic acids the carboxylic acid component of the polyamide may contain about 20 to 100 mol of polymeric fatty acid and about 0 to 80 mol of at least one c 4 c 12 dicarboxylic acid preferably this mixture contains about 30 to 95 mol of the polymeric fatty acid and about 5 to 70 mol of the c 4 c 12 dicarboxylic acids the monofunctional acid may be present in amounts of up to 20 mol i one or more aliphatic diamines with a number of carbon atoms in the chain of at least 4 whereby the amino groups are at the terminal ends of the carbon chain the aliphatic diamines may contain up to 20 carbon atoms and the aliphatic chain may be essentially linear or branched the most preferred aliphatic diamines are 1 4 butane diamine 1.