Polyamides having improved dyeability and thermal stability
AssigneeImperial Chemical Industries PLC
InventorsHarold George Burrows, Stephen John Hepworth
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Abstract
A method for improving the polymerization of polyamide compositions and the improved compositions formed thereby by polymerizing the polyamide in the presence of a small molar percent of a phosphonic acid salt of an organic diamine. The phosphonic acid salt increases the polymerization rate and results in a polymer of improved whiteness.
Claims24
A polyamide comprising recurring carbonamide groups separated from each other by 2 to 18 carbon atoms and 0.1 to 10 molar percent based on the molecular weight of the recurring units of the polyamide chain, of a salt of an organic diamine of 2 to 18 carbon atoms between amino groups with a phosphonic acid of the formula:
- ##EQU5## wherein R.sup.1 is an n-valent organic alkyl, cycloalkyl, aryl or aralkyl radical and n is an integer of from 1 to 3, said phosphonic acid salt being the predominate phosphorus material by molar percent.
Process for the manufacture of polyamides which comprises polymerising at elevated temperatures a polyamide-forming material selected from the group consisting of
- a. monoaminomonocarboxylic acids, and the corresponding lactams, having at least two carbon atoms between the amino and carboxylic acids, and
- b. substantially equimolecular proportions of a diamine having at least two carbon atoms between the amino groups and a dicarboxylic acid having at least two carbon atoms between the carboxylic acid groups, in the presence of from 0.1 to 10.0 molar percent, based on the molecular weight of the recurring units of the polyamide chain, of a salt of an organic diamine of 2 to 18 carbon atoms between amine groups with a phosphonic acid of the formula:
- ##EQU6## wherein R.sup.1 is an n-valent organic alkyl, cycloalkyl, aryl or aralkyl radical and n is an integer of from 1 to 3.
Dependencies are inferred from the claim text.