| abstract |
Thermoplastic polyamide resins with improved low-temperature flexibility and improved bonding properties consisting essentially of polycondensates of the following components: (a) 10 to 50 mol-% of a dimer fatty acid or mixture of such acids, (b) 5 to 45 mol-% of polyoxyalkylene urea diamine, (c) 0 to 25 mol-% of an aliphatic C6-C22 dicarboxylic acid or mixture of such acids, (d) 0 to 45 mol-% of an aliphatic, aromatic or cyclic C2-C40 diamine or a mixture of such diamines selected from the group comprising diprimary diamines, diamines containing secondary amino groups and alkyl substituents with no more than 8 carbon atoms at the nitrogen atom, and heterocyclic diamines capable of double amide formation. Preferred resins are base-terminated resins having amine values of up to 50 and acid-terminated resins having acid values of up to 20 and a molecular weight within the range from 5000 to 20,000 and preferably from 8000 to 15,000. The polyamide resins may be applied in as a melt between surfaces to be bonded and subsequently left to set for fixing and may be used either on their own or with other auxiliaries as hotmelt adhesives. |