High IV melt phase polyester polymer catalyzed with antimony containing compounds
View Patent ↗A melt phase process for making a polyester polymer melt phase product by adding an antimony containing catalyst to the melt phase, polycondensing the melt containing said catalyst in the melt phase until the It.V. of the melt reaches at least 0.75 dL/g. Polyester polymer melt phase pellets containing antimony residues and having an It.V. of at least 0.75 dL/g are obtained without solid state polymerization. The polyester polymer pellets containing antimony residues and having an It.V. of at least 0.70 dL/g obtained without increasing the molecular weight of the melt phase product by solid state polymerization are fed to an extruder, melted to produce a molten polyester polymer, and extruded through a die to form shaped articles. The melt phase products and articles made thereby have low b* color and/or high L* brightness, and the reaction time to make the melt phase products is short.
1. A process for making a polyester polymer melt phase product comprising:
a) esterifying or transesterifying a hydroxyl component and a dicarboxylic acid component comprising dicarboxylic acids, dicarboxylic acid derivatives, and mixtures thereof to produce an oligomeric mixture;
b) polycondensing the oligomeric mixture in a polycondensation zone to produce a polyester polymer melt having an It.V. of at least 0.75 dL/g; and
c) before the It.V. of the polyester polymer melt reaches 0.45 dL/g, adding an antimony containing catalyst to the oligomeric mixture or the polyester polymer melt or both, in any amount to provide from 180 ppm to 500 ppm antimony, based on the weight of the polyester polymer melt phase product; and
d) adding a catalyst stabilizer to the polyester polymer melt;
wherein the polyester polymer melt phase product has a b* color of −5 to +5 and an L* of at least 70.
2. The process of claim 1 , wherein the polyester polymer melt phase product has an L* of at least 74.
3. The process of claim 1 , comprising conducting said polycondensation reaction in the polycondensation zone at a temperature ranging from 270° C. to 300° C. throughout the polycondensation reaction commencing no later than when the It.V. of the melt reaches 0.45 dL/g and continuing at least until the It.V. of the melt reaches 0.75 dUg.
4. The process of claim 1 , wherein the reaction time to reach an It.V. of about 0.70 dL/g commencing from an It.V. in the melt of about 0.3 dL/g is 100 minutes or less.
5. The process of claim 1 , comprising adding a phosphorous containing compound as the catalyst stabilizer at a molar ratio of P:Sb of at least 0.025:1.
6. The process of claim 1 , further adding to the melt a compound which reduces antimony to a zero oxidation state.
7. The process of claim 1 , comprising adding a bluing toner.
8. The process of claim 1 , wherein the polyester polymer melt phase product comprises:
(a) a carboxylic acid component comprising at least 92 mole % of the residues of terephthalic acid or derivates of terephthalic acid, and
(b) a hydroxyl component comprising at least 92 mole % of the residues of ethylene glycol,
based on 100 mole percent of carboxylic acid component residues and 100 mole percent of hydroxyl component residues in the polyester polymer melt phase product.