CURING AGENTS HAVING LOW OR ZERO PHOSPHORUS-CONTENT FOR FORMALDEHYDE FREE DP FINISHING WITH POLYCARBOXYLIC ACIDS

The use of sodium bromide as a cocatalyst for DP finishing of cotton f abrics with polycarboxylic acids permits a decrease of as much as 75% in the amount of sodium hypophosphite required as a curing catalyst. T his lowers the chemical costs and the amount of phosphorus compounds t hat need to be recovered from spent treating solutions which in many s tates cannot be disposed of in rivers or lakes. Tertiary alkanolamines , as well as their phosphoric and metaphosphoric acid salts, also serv e to decrease the amount of hypophosphite catalyst needed. A feature o f triethanolamine as a crosslink modifier is that it increases the str ength and flex abrasion resistance retained by the fabric during DP tr eatment. In this respect, triethanolamine is superior to glycerol or p entaerythritol. The sodium salts of alpha-hydroxy polycarboxylic acids can serve as direct replacements for sodium hypophosphite or other ph osphorus compounds as curing agents for BTCA. In DP properties and dur ability to alkaline laundering, the treated fabrics perform nearly as well as those cured with sodium hypophosphite as catalyst and exhibit improved retention of tensile strength and flex abrasion resistance. S mall amounts of boric acid in the formulation maintain fabric whitenes s during heat curing.