Polyamides useful as hotmelt adhesives and having improved resistance to hydrocarbons such as gasoline are obtained by reacting a) an acid component containing at least one C 6 to C 22 aliphatic dicarboxylic acid and b) an amine component containing at least one straight chain alkylene diamine having from 2 to 8 carbon atoms and at least one heterocyclic secondary diamine. The amine component may optionally also contain at least one branched chain alkylene diamine having from 3 to 10 carbon atoms and/or at least one C 24 to C 48 dimer amine.
1. A polyamide which is the reaction product of a) an acid component comprising one or more C 6 to C 22 aliphatic dicarboxylic acids, wherein at least 90 mole % of said acid component is comprised of said one or more C 6 to C 22 aliphatic dicarboxylic acids and b) an amine component comprising at least one straight chain alkylene diamine having from 2 to 8 carbon atoms and at least one heterocyclic secondary diamine.
2. A polyamide according to claim 1 wherein the amine component is additionally comprised of at least one branched chain alkylene diamine having from 3 to 10 carbon atoms.
3. A polyamide according to claim 1 wherein the amine component is additionally comprised of at least one C 24 to C 48 dimer amine.
4. A polyamide according to claim 1 wherein the amine component is additionally comprised of at least one C 24 to C 48 dimer amine and at least one branched chain alkylene diamine having from 3 to 10 carbon atoms.
5. A polyamide according to claim 1 wherein the amine component comprises piperazine.
6. A polyamide according to claim 1 wherein the amine component comprises piperazine and ethylenediamine.
7. A polyamide according to claim 1 wherein the amine component comprises 2-methyl-1,5-pentanediamine.
8. A polyamide according to claim 1 wherein the acid component comprises at least one C 10 to C 14 aliphatic dicarboxylic acid.
9. A polyamide according to claim 1 wherein the amine component comprises hexamethylenediamine.
10. A polyamide according to claim 1 wherein the acid component comprises sebacic acid.
11. A polyamide according to claim 1 wherein the amine component comprises at least one straight chain alkylene diamine having from 2 to 4 carbon atoms.
12. A polyamide according to claim 1 wherein the straight chain alkylene diamine is ethylenediamine.
13. A polyamide according to claim 1 wherein the amine component additionally comprises at least one C 32 to C 40 dimer amine.
14. A polyamide according to claim 1 wherein the amine component additionally comprises at least one C 36 dimer amine.
15. A polyamide according to claim 1 wherein the amine component comprises piperazine, ethylene diamine, and 2-methyl-1,5-pentanediamine.
16. A polyamide obtained by condensation polymerization of a mixture of monomers consisting essentially of sebacic acid, ethylenediamine, piperazine, at least one dimer amine and 2-methyl-1,5-pentanediamine.
17. A polyamide obtained by condensation polymerization of a mixture of monomers consisting essentially of octadecanedicarboxylic acid, hexamethylenediamine and piperazine.
18. A polyamide according to claim 17 wherein the equivalent ratio of hexamethylenediamine:piperazine is at least 0.1:1 and is no greater than to 0.4:1.
19. A polyamide obtained by condensation polymerization of a mixture of monomers consisting essentially of a) one or more dicarboxylic acids selected from the group consisting of dodecanedicarboxylic acid and sebacic acid, b) hexamethylenediamine and c) piperazine.
20. A polyamide according to claim 19 wherein the equivalent ratio of hexamethylenediamine:piperazine is at least 0.6:1 and independently is no greater than 1.4:1.