US 12,392,057 B2
Polyester fiber, preparaion method thereof and molded article formed therefrom
Boo-youn Lee, Gyeonggi-do (KR); Sung-Gi Kim, Gyeonggi-do (KR); and Yoo Jin Lee, Gyeonggi-do (KR)
Assigned to SK Chemicals CO., Ltd., Gyeonggi-do (KR)
Filed by SK CHEMICALS CO., LTD., Gyeonggi-do (KR)
Filed on Oct. 19, 2023, as Appl. No. 18/490,393.
Application 18/490,393 is a division of application No. 16/616,078, abandoned, previously published as PCT/KR2018/006322, filed on Jun. 1, 2018.
Claims priority of application No. 10-2017-0069239 (KR), filed on Jun. 2, 2017.
Prior Publication US 2024/0044051 A1, Feb. 8, 2024
Int. Cl. C08G 63/672 (2006.01); B29C 48/00 (2019.01); B32B 27/08 (2006.01); C08G 63/183 (2006.01); C08G 63/86 (2006.01); C08J 5/18 (2006.01); C08K 3/04 (2006.01); C08K 3/24 (2006.01); C08K 3/32 (2006.01); C08K 5/098 (2006.01); D01D 5/098 (2006.01); D01F 1/09 (2006.01); D01F 1/10 (2006.01); D01F 6/62 (2006.01)
CPC D01F 6/62 (2013.01) [C08G 63/183 (2013.01); C08G 63/863 (2013.01); C08K 3/04 (2013.01); C08K 3/24 (2013.01); C08K 3/32 (2013.01); D01D 5/098 (2013.01); D01F 1/09 (2013.01); D01F 1/10 (2013.01); D01F 1/106 (2013.01); C08K 2003/329 (2013.01)] 6 Claims
 
1. A method for preparing a polyester fiber comprising the steps of:
(a) carrying out an esterification reaction of a dicarboxylic acid including terephthalic acid thereof and a diol comprising 1 mol to 25 mol of isosorbide and 65 mol to 200 mol of ethylene glycol based on 100 mol of the total dicarboxylic acid;
(b) subjecting the esterification reaction product to a polycondensation reaction to prepare a polyester resin polymerized with a dicarboxylic acid including terephthalic acid and a diol including isosorbide, thereby having an alternating structure of an acid moiety derived from the dicarboxylic acid and a diol moiety derived from the diol, wherein the polyester resin includes 1 to 20 mol % of a diol moiety derived from isosorbide and 2 to 5 mol % of a diol moiety derived from diethylene glycol based on the total diol moieties derived from the diol;
(c) melt-spinning the polyester resin obtained in step (b) at 240° C. to 310° C.; and
(d) drawing the melt-spun undrawn fiber obtained in step (c) at a temperature equal to or higher than the glass transition temperature of the polyester resin,
wherein, in step (a), the initial mixing molar ratio of the dicarboxylic acid to the diol is adjusted to 1:1.01 to 1.05, and
wherein in step (b), the polycondensation is carried out so that an intrinsic viscosity, which is measured at 35° C. after dissolving the product obtained by the polycondensation reaction in orthochlorophenol at a concentration of 1.2 g/dl at 150° C. for 15 minutes, reaches 0.45 dl/g to 0.75 dl/g,
wherein the polyester resin has an alternating structure of an acid moiety derived from the dicarboxylic acid and diol moieties derived from the diol, the dicarboxylic acid includes 90 mol % or more of the terephthalic acid based on the total dicarboxylic acid, and the polyester resin includes 1 to 20 mol % of a diol moiety derived from isosorbide, 2 to 5 mol % of a diol moiety derived from diethylene glycol, and the remainder of a diol moiety derived from ethylene glycol, based on the total diol moieties derived from the diol, and
wherein the polyester resin has a molecular weight distribution of 2.8 to 4.0.