Catalyst systems for crystallizable reactor grade resins with recycled content

A process for producing a polyester composition from recycled polyesters comprising:

• (a) introducing terephthalic acid (TPA);
• and ethylene glycol (EG);
• and recycled polyesters comprising one or more of recycled PET, recycled PETG, recycled PCT, recycled PCTA or recycled PCTG into a paste tank to form a slurry that is stirred and heated at temperatures up to 150° C.;
• (b) passing the paste tank slurry to a first reaction zone;
• (c) introducing one or more of additional glycol comprising 1,4-cyclohexanedimethanol (CHDM), neopentyl glycol (NPG) or diethylene glycol (DEG), and optionally adding additional terephthalic acid (TPA);
• and ethylene glycol (EG) to a total glycol:
• TPA molar ratio of 1:1 to 4:1 into the first reaction zone, optionally in the presence of an esterification catalyst comprising a titanium compound and an antimony compound and/or a stabilizer comprising a phosphorus compound;
• (d) reacting the TPA and EG and the recycled polyesters with the one or more additional glycol in the first reaction zone at a melt temperature of at least 200° C. to form a first esterification product comprising oligomers and unreacted TPA, EG, and the additional glycol(s);
• (e) passing the first esterification product to a second reaction zone;
• (f) reacting further the first esterification product and optionally additional added glycols in the second reaction zone at a melt temperature of at least 200° C. to form a second esterification product comprising polyester oligomers, optionally in the presence of an esterification catalyst comprising a titanium compound and an antimony compound and/or a stabilizer comprising a phosphorus compound;
• (g) passing the second esterification product to a third reaction zone;
• (h) polycondensing the second esterification product in the third reaction zone to form a polymerization product comprising polyesters, optionally in the presence of a polycondensation catalyst comprising a titanium compound and an antimony compound and/or a stabilizer comprising a phosphorus compound.