| abstract |
A cationic-dyeable polyamide, polymerized from omega aminocarboxylic acids or their lactams, of improved physical properties can be made by using from 0.25 to 0.85 mole percent (based on the polyamide) of the sodium salt of a sulfonated dicarboxylic acid such as 5-sulfoisophthalic acid and 0.07 to 0.65 mole percent of an N-sulfoalkyl alkyldiamine such as N-(4sulfobutyl)hexamethylenediamine, or N-(2-sulfoethyl)mxylylenediamine. A polyamide results containing the respectively same number of sulfo groups, but with less diluent and consequently having a higher melting point. The diacid can be a sulfonate derivative of a phthalic acid, or of fluorene, etc. The diamine can be a sulfonate derivative of hexamethylenediamine, metaxylylenediamine, etc. The use of the combination of additives eliminates the necessity of adding a diamine or dicarboxylic acid to achieve full polymerization. |