GB1329858A - Sewing thread and a method of preparing the same - Google Patents

Abstract

1329858 Modified polypivalolactone filaments KANEBO Ltd 7 Oct 1970 [8 Oct 1969 13 Nov 1969 8 Dec 1969(2) 4 April 1970 25 June 1970] 47646/70 Heading B5B [Also in Divisions C7 and D1] A sewing thread comprising at least one thermoplastic elastic fibre component and having a titre of no less than 70 denier, an initial modulus of elasticity in tension of no less than 0À5 g/den., an elongation at break of no less than 30% and an elastic recovery at 25% elongation of no less than 70% may be prepared from pivalolactone polymer fibres modified either by subjecting a hot drawn polypivalolactone yarn to a first heating at a temperature above 150‹ C. under a tension of at least 0À2 g/den. for at least 0À1 second and second heating at a temperature above 110‹ C. and below the temperature of said first heating under relaxed conditions for no less than 1 second or by treating a multifilament polypivalolactone yarn with an oiling agent containing a phenolic antioxidant and a swelling agent comprising a non-ionic surface active agent and/or a neutral oil and subjecting the resultant multi-filament yarn to continuous heating at a temperature between 35‹ C. below the melting point of the polypivalolactone and said melting point to obtain an agglutinated multifilament yarn. Preferably the sewing thread has a breaking tenacity of no less than 1À5 g/den., an elongation at break greater than 50%, an initial modulus of no less than 5 g/den., a yield strength of no less than 0À6 g/den., a shrinkage in boiling water of no more than 1% and comprises from 3% to 97% by weight of the thermoplastic elastic fibre component and from 97% to 3% by weight of at least one non-elastic fibre component. In examples twisted (S and/or Z directions) polypivalolactone yarns are used alone or doubled and twisted with cotton yarn, polyester yarn, acrylic spun yarn or silk yarn as sewing threads for lock and/or chain stitching of e.g. underwear, athletic vests, sweaters etc. Elastic yarns prepared from copolyamides of sebacic acid with substituted and unsubstituted hexamethylene diamine and yarns prepared from a block copolymer of polypivalolactone and 5 mole per cent polyethylene oxide are also used.