GB902907A - Improvements in or relating to filamentary structures and films - Google Patents

Abstract

A process for the production of a polyamide filamentary structure or film having a reduced tendency to yellow comprises melt-spinning or melt-extruding into an unconfined space a polyamide which has been obtained by melt polymerization in the presence of a dissolved phosphinate anti-oxidant compound of the formula:- <FORM:0902907/IV(a)/1> where R is a substituted or unsubstituted alkyl, aryl or aralkyl group, X is a substituted or unsubstituted alkyl, aryl or aralkyl group or a metal or an alkyl-substituted ammonium ion, or X and R are together an alkylene ring structure, and which still contains the said phosphinate compound, with the proviso that where copper and halide salts are present during the polymerization the said filamentary structure or film is scoured prior to heat setting to remove at least part of the phosphinate compound therefrom. The term "alkyl" as used in the Specification includes cycloalkyl and alkenyl. The term "scouring" signifies a treatment wherein the filamentary structure or film is contacted with a solvent for the phosphinate compound. Preferred antioxidants are sodium m-ethylphenylphosphinate, sodium o-ethylphenylphosphinate and barium 2,5-dimethylphenylphosphinate. Specified polyamides are those derived from aminoacids or dicarboxylic acids and diamines. The examples describe the polymerization of hexamethylene diammonium adipate in the presence of:- (1) hexamethylene diammonium phenylphosphinate; (2) sodium 2-hydroxybutyl-2-phosphinate; (3) sodium ethylphosphinate; (4) sodium isobutylphosphinate; (5) sodium 3-pentylphosphinate; (6) sodium cyclopentylphosphinate; (7) sodium cyclohexylphosphinate; (8) sodium 2-methylcyclohexylphosphinate; (9) sodium isooctenylphosphinate; (10) sodium isooctylphosphinate; (11) sodium n-octylphosphinate; (12) sodium styrylphosphinate; (13) disodium 1,6-hexyldiphosphinate; (14) sodium 3-hydroxylpropylphosphinate; (15) sodium 3-hydroxy -2-methylpropylphosphinate; (16) potassium 3-hydroxy-2-methylpropylphosphinate; (17) potassium 2-hydroxybutyl-2-phosphinate; (18) potassium 1-hydroxy-1-phenethylphosphinate; (19) sodium a -hydroxyldiphenylmethylphosphinate; (20) sodium a -(n-butylamino)isopropylphosphinate; (21) sodium a -(2-phenethylamino)isopropylphosphinate; (22) sodium 1-carboxypropyl-2-phosphinate; (23) sodium 4-carbomethoxybutylphosphinate; (24) sodium 4-cyanobutylphosphinate; (25) disodium 1,8-diaminoactyl-3,6-diphosphinate; (26) sodium 1,2-dicarboxyethylphosphinate; (27) sodium 1,4-dicarboxybutyl-2-phosphinate; (28) sodium 1,4-dicyanobutyl-2-phosphinate; (29) magnesium phenylphosphinate; (30) calcium phenylphosphinate; (31) barium phenylphosphinate; (32) manganous phenylphosphinate; (33) aluminium phenylphosphinate; (34) stannous phenylphosphinate; (35) stannic phenylphosphinate; (36) potassium p-dodecylphenylphosphinate; (37) sodium p-dimethylaminophenylphosphinate; (38) potassium p-dimethylaminophenylphosphinate; (39) sodium p-(b -carboxyethyl)phenylphosphinate; (40) tetramethylammonium phenylphosphinate; (41) 3-hydroxypropylphosphinic acid phostone; (42) 3-hydroxy-2-methylpropyl phosphinic acid phostone; (43) sodium o-ethylphenylphosphinate; (44) sodium m-ethylphenylphosphinate; (45) sodium 2,3-dimethylphenylphosphinate; (46) barium 2,5-dimethylphenylphosphinate; (47) sodium p-ethylphenylphosphinate; (48) sodium p-isopropylphenylphosphinate; (49) sodium p-methoxyphenylphosphinate and (50) sodium p-bromophenylphosphinate, the polymers being extruded as ribbon, quenched, cut into chips, steam spun through a 13-hole spinneret and cold drawn; scouring being effected when applicable at the boil in water containing palm oil soap, sodium lauryl sulphate and trisodium phosphate. The Specification disclaims the subject-matter of Specification 902,905 which describes and claims a similar process in which is used a phenylphosphinate compound of the formula:- <FORM:0902907/IV(a)/2> where M is an alkali metal and R, R1 and R11 are hydrogen or methyl groups. Specifications 506,125, 533,306, 554,718 and 653,257 also are referred to.