Non-pilling polyester fibres
The invention relates to a method for producing non-pilling polyester fibres, whereby polyethylene terephthalate is produced in the presence of organosilicon compounds of tetrahydrofurfuryl alcohol. Preferably, tetrakistetrahydrofurfuryloxysilane or tris[tetrahydrofuryloxy]methylsilane is used.
1. A process for producing low pill polyester fibers by transesterifying of at least one dialkyl dicarboxylate or esterifying of at least one dicarboxylic acid with at least one diol and subsequent precondensing and polycondensing in the presence of a catalyst and using organosilicon compound, comprising at least one substituent of the formula:
on the silicon and processing the polycondensate obtained into fibers.
2. A process according to claim 1 , wherein the organosilicon compound used is tetrakistetrahydrofurfuryloxysilane.
3. A process according to claim 1 , wherein the organosilicon compound used is tristetrahydrofurfaryloxymethylsilane.
4. A process according to claim 1 wherein the process is operated continuously.
5. A process according to claim 1 , wherein the process is operated batchwise.
6. A process according to claim 1 , wherein the organosilicon compound is used in an amount of 100–2000 ppm, reckoned as silicone and based on weight reaction mixture.
7. A process according to claim 1 , wherein the organosilicon compound is added after transesterification of dialkyl carboxylate with at least one diol.
8. A process according to claim 1 wherein the alkyl dicarboxylate used is dimethyl terephthalate.
9. A process according to claim 1 , wherein the organosilicon compound is added at a time when the polycondensate has a molecular weight M w of 3000–20000 g/mol.
10. A process according to claim 1 , wherein the organosilicon compound is added at a time when the pressure of the polycondensation is 0.5 mbar –1.5 bar.
11. A process according to claim 1 , wherein the organosilicon compound is added to the polycondensation melt at a time when the carboxyl group content of the polycondensate is less than 35 mmol/kg.
12. The process of claim 1 , wherein the fiber is treated with an aqueous medium.
13. A process according to claim 12 , wherein the treatment with the aqueous medium is carried out at temperatures of 80–150° C.
14. Low pill polyester fibers obtained by a process of claim 1 .