A type of high-modulus-low-shrinkage activated PET industrial yarn and preparing method thereof are disclosed. The preparing method is to manufacture filament from a modified polyester, which is the product of the esterification and the successive polycondensation reactions of evenly mixed terephthalic acid, ethylene glycol and tert-butyl branched heptanediol, through a series of processes composed of viscosity enhancing by solid state polycondensation, melting, metering, extruding, cooling, oiling, stretching, heat setting, relaxation heat-treating, oiling with activation oil, winding and pre-activation treatment. The relaxation heat-treating indicates passing the modified polyester yarns through a space with a certain temperature within 200-220° C. under a proper relaxation state; and the proper relaxation state means a 3.0-5.0% of overfeed for the winding. The improvement of activator efficiency by importing the tert-butyl branched diol into the polyester, together with the synergistic effect of heat setting temperature and high winding overfeed rate, will reduce the fiber thermal shrinkage.

A type of easy-to-dye degradable polyester FDY and preparing method thereof are disclosed. The method for preparing an easy-to-dye degradable polyester FDY is to prepare a modified polyester FDY from a modified polyester melt with FDY process; wherein the material is a modified polyester; wherein the modified polyester has a molecular chain structure composed of terephthalic acid segments, ethylene glycol segments, 2,2,3,4,5,5-hexamethyl-3,4-hexanediol segments and tert-butyl branched heptanediol segments; wherein the modified polyester is dispersed by solid heteropolyacid powder calcined at a 400˜700° C. temperature. The preparing method has a simple process, modifying the polyester through solid heteropolyacid, tert-butyl branched heptanediol and 2,2,3,4,5,5-hexamethyl-3,4-hexanediol, which increases the hydrolysis rate of the polyester, improves the dyeing performance and prepares products with excellent mechanical properties.

The present application discloses a method for preparing polyester polyol comprising performing transesterification of raw materials containing inorganic oxyacid ester and polyhydric alcohol to obtain the polyester polyol. The polyester polyol obtained by the method described in the present application has higher heat resistance.

A polyethylene terephthalate composition (PET), an injection-molded bottle preform made from a PET composition, a refillable PET container blow-molded from the preform, catalyst compositions used for making the PET composition, methods for making the PET composition, methods for injection-molding a PET bottle preform, methods for blow-molding a refillable PET bottle from a preform and methods for improving the rewash stability and recyclability of refillable PET bottles particularly for carbonated soft drinks.

The present disclosure relates to crystallizable shrinkable films and thermoformable films or sheets comprising amorphous polyester compositions which comprise residues of terephthalic acid, neopentyl glycol (NRG), 1,4-cyclohexanedimethanol CHDM), ethylene glycol (EG), and diethylene glycol (DEG), in certain compositional ranges having certain advantages and improved properties. The present disclosure also relates to crystallizable shrinkable films and thermoformable film(s) and/or sheet(s) comprising polyester compositions which comprise residues of recycled terephthalic acid, recycled neopentyl glycol (NRG), recycled 1,4-cyclohexanedimethanol (CHDM), recycled ethylene glycol (EG), and recycled diethylene glycol (DEG), in certain compositional ranges having certain advantages and improved properties.

The present invention relates to the process for manufacturing specialty polyesters & copolyesters from recycled Bis 2-Hydroxyethyl terephthalate (rBHET) derived from Polyethylene terephthalate (PET) recycled from PET scraps or waste. The polyesters/co-polyesters thus obtained are clean and of high quality which can be used for all applications but not limited to textiles, packaging, engineering and industry.

A polyethylene terephthalate composition (PET), an injection-molded bottle preform made from a PET composition, a refillable PET container blow-molded from the preform, catalyst compositions used for making the PET composition, methods for making the PET composition, methods for injection-molding a PET bottle preform, methods for blow-molding a refillable PET bottle from a preform and methods for improving the rewash stability and recyclability of refillable PET bottles particularly for carbonated soft drinks.

A type of degradable polyester fiber and preparing method thereof are disclosed. The preparing method is to melt spinning a modified polyester with the fully drawn yarn (FDY) technique, and the modified polyester is composed of the terephthalic acid segments, the ethylene glycol segments, the 2,5,6,6-tetramethyl-2,5-heptanediol segments and the fluorinated dicarboxylic acid segments, wherein the fluorinated dicarboxylic acid is one selected from 2,2-difluoro-1,3-malonic acid, 2,2-difluoro-1,4-succinic acid, 2,2-difluoro-1,5-glutaric acid and 2,2,3,3-tetrafluoro-1,4-succinic acid. Moreover, the modified polyester is dispersed with the doped ZrO.sub.2 powder. The obtain fiber has an intrinsic viscosity drop of 23-28% when stored at 25° C. and R.H. 65% for 60 months. The method herein is of low cost and easy technologies, whereas the obtained fiber has a rapid natural degradation rate and a wide application prospect.

A catalyst composition for a polyester manufacturing process, comprising a titanium catalyst and/or an antimony catalyst as main catalyst, and either (i) at least one co-catalyst A, or (ii) at least one co-catalyst Band at least one co-catalyst C, or (iii) a combination thereof, and wherein co-catalyst A is selected from the group consisting of a metal salt of an alkyl or an aryl phosphinic acid, or a metal salt of an alkyl or aryl diphosphinic acid, or a combination thereof, and co-catalyst B is selected from the group consisting of an alkyl or aryl phosphinic acid, an alkyl or aryl diphosphinic acid a combination thereof, and co-catalyst C selected from the group of a metal salt, a metal hydroxide or a metal organyl compound.

A type of easy-to-dye degradable polyester FDY and preparing method thereof are disclosed. The method for preparing an easy-to-dye degradable polyester FDY is to prepare a modified polyester FDY from a modified polyester melt with FDY process; wherein the material is a modified polyester; wherein the modified polyester has a molecular chain structure composed of terephthalic acid segments, ethylene glycol segments, 2,2,3,4,5,5-hexamethyl-3,4-hexanediol segments and tert-butyl branched heptanediol segments; wherein the modified polyester is dispersed by solid heteropolyacid powder calcined at a 400˜700° C. temperature. The preparing method has a simple process, modifying the polyester through solid heteropolyacid, tert-butyl branched heptanediol and 2,2,3,4,5,5-hexamethyl-3,4-hexanediol, which increases the hydrolysis rate of the polyester, improves the dyeing performance and prepares products with excellent mechanical properties.