Antistatic polyester false twisted yarn, process for its production, and antistatic special conjugated false twisted yarn comprising antistatic polyester false twisted yarn

Abstract

An unstretched filament composed of a PET-based aromatic polyester multifilament comprising a polyoxyalkylene-based polyether and an organic ionic compound is subjected to simultaneous stretching and false twisting under specified conditions to produce a polyester false twisted yarn, whereby rapid and stable false twisting can be accomplished without section deformation or fluff generation during false twisting, and the resulting yarn has a highly satisfactory hand quality and a fibrillation resistant fiber structure, while also exhibiting a highly durable antistatic property. Interlacing of the unstretched filament with an unstretched polyester filament comprising a polymethyl methacrylate-based polymer and/or polystyrene-based polymer and stretching/false twisting thereof under specified conditions allows rapid and stable production of conjugated false twisted yarn exhibiting highly satisfactory bulkiness and a spun feel with the absence of fluff, as well as a highly durable antistatic property. The finished yarn is particularly useful for purposes that require static electricity to be inhibited, such as student wear, uniforms, dustproof clothing and the like.

1 . An antistatic polyester false twisted yarn which is an antistatic polyester multifilament false twisted yarn made from an aromatic polyester composition comprising (a) a polyoxyalkylene-based polyether and (b) an organic ionic compound that is substantially non-reactive with aromatic polyesters, wherein at least 75 mol % of the repeating units are ethylene terephthalate units, the false twisted yarn being characterized in that the electrostatic voltage half-life is no longer than 60 seconds and the percentage crimp is 10-20%. 
   
   
       2 . An antistatic polyester false twisted yarn according to  claim 1 , which comprises 0.2-30 parts by weight of the (a) polyoxyalkylene-based polyether and 0.05-10 parts by weight of the (b) organic ionic compound which is substantially non-reactive with aromatic polyesters, with respect to 100 parts by weight of the aromatic polyester. 
   
   
       3 . An antistatic polyester false twisted yarn according to  claim 1 , wherein the total size is 50-200 dtex. 
   
   
       4 . A process for production of an antistatic polyester false twisted yarn, characterized by simultaneous stretching and false twisting of an unstretched filament with a birefringence of 0.02-0.05, obtained by melt spinning of an aromatic polyester composition comprising (a) a polyoxyalkylene-based polyether and (b) an organic ionic compound that is substantially non-reactive with aromatic polyesters, wherein at least 75 mol % of the repeating units are ethylene terephthalate units, under conditions satisfying all of the following (a) to (d):
 (a) the false twisting tool used is a three-axis friction disc type wherein the material of the lowermost disc positioned at the untwisting section is ceramic, the contact length between that disc and the running yarn is 2.5-0.5 mm, and the diameter of the disc is 90-98% of the diameter of the disc immediately above it;   (b) the false twisting temperature is 170° C.-300° C;   (c) the draw ratio during false twisting is 1.4-2.4; and   (d) the number of false twists T (/m) is 15,000/Y 1/2 ≦T≦35,000/Y 1/2 , with respect to the size (Y dtex) of the false twisted yarn.   
   
   
       5 . A production process according to  claim 4  for an antistatic polyester false twisted yarn which comprises 0.2-30 parts by weight of the (a) polyoxyalkylene-based polyether and 0.05-10 parts by weight of the (b) organic ionic compound which is substantially non-reactive with aromatic polyesters, with respect to 100 parts by weight of the aromatic polyester. 
   
   
       6 . A process for production of an antistatic polyester false twisted yarn according to  claim 4 , characterized by carrying out interlacing treatment with air pressure applied to the unstretched filament that is to be simultaneously stretched and false twisted. 
   
   
       7 . An antistatic special conjugated false twisted yarn wherein the core yarn (A) is an antistatic polyester multifilament composed of an aromatic polyester composition having ethylene terephthalate units for at least 75 mol % of the repeating units and comprising (a) a polyoxyalkylene-based polyether and (b) an organic ionic compound that is substantially non-reactive with polyesters, and the sheath yarn (B) is a polyester multifilament composed of an aromatic polyester composition comprising 0.5-3.0 wt % of a polymethyl methacrylate-based polymer and/or polystyrene-based polymer, the special conjugated false twisted yarn being characterized in that the electrostatic friction pressure of the finished yarn is no greater than 2000 V, the percentage crimp is 2-8% and the average filament length of the sheath yarn (B) is 10-20% longer than the average filament length of the core yarn (A). 
   
   
       8 . An antistatic special conjugated false twisted yarn according to  claim 7 , wherein the core yarn (A) is composed of an aromatic polyester composition comprising 0.2-30 parts by weight of the (a) polyoxyalkylene-based polyether and 0.05-10 parts by weight of the (b) organic ionic compound which is substantially non-reactive with aromatic polyesters, with respect to 100 parts by weight of the aromatic polyester. 
   
   
       9 . A process for production of an antistatic special conjugated false twisted yarn, characterized in that the texturing filament to be used for polyester multifilament stretching and false twisting is obtained by doubling an unstretched antistatic polyester multifilament (A′) comprising (a) a polyoxyalkylene-based polyether and (b) an organic ionic compound that is substantially non-reactive with polyesters and an unstretched polyester multifilament (B′) comprising 0.5-3.0 wt % of a polymethyl methacrylate-based polymer and/or polystyrene-based polymer based on the weight of the polyester multifilament, and simultaneous stretching and false twisting are carried out under conditions satisfying all of the following (1)-(4).
 (1) air interlacing treatment is carried out immediately before false twisting to produce at least 30 tangles per meter;   (2) the false twisting tool used is a three-axis friction disc type wherein the material of the lowermost disc positioned at the untwisting section is ceramic, the contact length between that disc and the running yarn is 2.5-0.5 mm, and the diameter of the disc is 90-98% of the diameter of the disc immediately above it;   (3) the false twisting temperature is 170° C.-300° C. and   (4) the number of false twists T (/m) is 15,000/Y 1/2 ≦T≦35,000/Y 1/2 , with respect to the size (Y dtex) of the false twisted yarn.   
   
   
       10 . A process for production of an antistatic special conjugated false twisted yarn according to  claim 9 , wherein the unstretched antistatic polyester multifilament (A′) is composed of an aromatic polyester composition comprising 0.2-30 parts by weight of the (a) polyoxyalkylene-based polyether and 0.05-10 parts by weight of the (b) organic ionic compound which is substantially non-reactive with aromatic polyesters, with respect to 100 parts by weight of the aromatic polyester. 
   
   
       11 . An antistatic polyester false twisted yarn according to  claim 2 , wherein the total size is 50-200 dtex. 
   
   
       12 . A process for production of an antistatic polyester false twisted yarn according to  claim 5 , characterized by carrying out interlacing treatment with air pressure applied to the unstretched filament that is to be simultaneously stretched and false twisted.