Process for producing antimony-free pet polyester fiber excellent in no yellowish look
AssigneeNan Ya Plastics Corporation
InventorZo-Chun JEN
Life of this patent
Estimating the term…
Abstract
An antimony-free PET resin produced by using an inorganic Ti—Mg catalyst and a small amount of blue and red dyes, in the absence of an antimony catalyst or a phosphorus stabilizer; and, in a melt spinning process for producing PET polyester fiber, the PET resin demonstrates excellent spinnability but no yarn breaks or aggregation of TiO2 delustering agent so that the resultant PET polyester fiber features commercially desired in both color tone and glossiness. Especially the PET resin and the PET polyester fiber containing no antimony are therefore environmentally friendly by causing no heavy metal pollution to the environment.
Claims3
A process for producing antimony-free polyethylene terephthalate (PET) polyester fiber excellent in no yellowish look, comprising the steps of:
- (a) producing an inorganic Ti—Mg polycondensation catalyst synthesized by chemical precipitation and satisfied requirements of containing titanium element ranging from 1 to 20 wt %, being made in form of titanium dioxide (TiO2) covered on magnesium hydroxide (Mg(OH)2) to obtain a molar ratio of titanium to magnesium ranging from 0.005 to 1 and having an particle size between 0.1 to 1.0 μm;
- (b) producing an antimony-free polyethylene terephthalate (PET) in the absence of an antimony catalyst and a phosphorus stabilizer, comprising the steps of
- (i) undergoing a first-stage direct esterification reaction in a reactor to obtain a reaction mixture by reacting purified terephthalic acid with ethylene glycol;
- (ii) after step (i) being completed, based on the total reaction mixture weight, adding the following additives into the reactor at same time:
- (1) the inorganic Ti—Mg catalyst made of step (a) in an amount of ranging from 30 to 150 ppm, wherein the inorganic Ti—Mg catalyst containing titanium element 2 to 10 ppm;
- (2) a blue dye in an amount of ranging from 1 to 5 ppm;
- (3) a red dye in an amount of ranging from 1 to 3 ppm and
- (4) titanium dioxide (TiO2) in an amount of ranging from 0 to 4 wt %;
- and
- (iii) undergoing a second-stage polycondensation to obtain a polyethylene terephthalate (PET) resin, containing polyethylene terephthalate (PET), blue dye, red dye and titanium dioxide (TiO2), with intrinsic viscosity ranging from 0.5 to 0.7 dl/g;
- and
- (c) by a melt spinning process to obtain a glossiness of PET polyester fiber excellent in no yellowish color produced from the polyethylene terephthalate (PET) resin of step (b).
Dependencies are inferred from the claim text.