A type of polyester yarn for an industrial sewing thread and preparing method thereof are provided. The preparing method is composed of a viscosity enhancing by a solid state polycondensation and a melt spinning for a modified polyester, and the modified polyester is a product of esterification and polycondensation of evenly mixed terephthalic acid, ethylene glycol, tert-butyl branched dicarboxylic acid, trimethylsilyl branched diol and a doped Sb.sub.2O.sub.3 powder, wherein the tert-butyl branched dicarboxylic acid is selected from the group consisting of 5-tert-butyl-1,3-benzoic acid, 2-tert-butyl-1,6-hexanedioic acid, 3-tert-butyl-1,6-hexanedioic acid and 2,5-di-tert-butyl-1,6-hexanedioic acid. Moreover, the modified polyester is dispersed with a doped ZrO.sub.2 powder. An obtained fiber has an intrinsic viscosity drop of 23-28% when stored at 25° C. and R.H. 65% for 60 months.

A flame-retardant polyester fiber obtained by spinning flame-retardant polyester and irradiating with ultraviolet light and having a limiting oxygen index value of greater than 30. Flame retardant 2-carboxyethylphenylphosphinic acid to improve the flame retardant properties of polyester, the use of polyester containing unsaturated double bond in UV irradiation, the double bond opens to form a crosslinking point, the formation of a certain amount of the network structure improves the heat-resistant temperature of the poly-fiber and improves the anti-dripping performance of the polyester fiber.

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 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.

The present invention relates to a polyester container. The polyester container is formed from a polyester resin containing a particular content of diol moieties derived from isosorbide and diethylene glycol, and thus can show high transparency in spite of a great wall thickness thereof.

A process for producing a polyester having 2,5-furandicarboxylate units includes: a) providing or producing a starting composition including 2,5-furandicarboxylic acid, an aliphatic diol and a suppressant for suppressing ether formation between the aliphatic diol molecules, b) subjecting the starting composition to esterification conditions to produce an ester composition, and c) contacting the ester composition with a germanium containing catalyst at polycondensation conditions to produce a polyester including 2,5-furandicarboxylate units, where the suppressant includes amines and lithium hydroxide.

The present invention relates to a polyester container. The polyester container is formed from a polyester resin containing a particular content of diol moieties derived from isosorbide and diethylene glycol, and thus can show high transparency in spite of a great wall thickness thereof.

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.