A method of producing copolyester material with peptide and is disclosed. The method includes: putting ethylene glycol, collagen peptide and Benzenedicarboxylic acid into a container, and mixing them to form a mixture; heating the mixture for executing an esterification reaction, to product esters and water; heating the esters to a first temperature, and stirring the esters via a mixer; in a specific period, decreasing the pressure in the container to a first pressure for executing a polycondensation reaction; decreasing the pressure in the container to a second pressure, and stirring the esters via the mixer, to produce a copolyester material with peptide.

A polyethylene terephthalate resin composition which is characterized by having a manganese element content of 30 to 60 ppm, a potassium element content of 2 to 10 ppm, an antimony element content of 70 to 150 ppm, a molar ratio of metal elements to phosphorus element (M/P=(M1+M2/2)/P) satisfying formula (1), and a gelation ratio of 5% by weight or less:

0.6(M1+M2/2)/P1.3(1)

wherein M1 represents the content (mol/t) of a bivalent metal element selected from the group consisting of Mg, Mn, and Ca; M2 represents the content (mol/t) of a monovalent metal element selected from the group consisting of Li, Na, and K; and P represents the content (mol/t) of phosphorus element.

A high-strength thermal-stability polyester industrial yarn is prepared by spinning, winding and coordination treatment of a modified polyester after a solid-state polycondensation; wherein the method of coordination treatment comprises: soaking the wound fiber in an aqueous solution of a coordination agent, and the concentration of the aqueous solution of the coordination agent is 0.1-0.2 mol/L; wherein the condition of coordination treatment is 48-72 hours at 80-100? C., and the concentration of the aqueous solution of the coordination agent is 0.1-0.2 mol/L; wherein the polyester segments of the prepared high-strength thermal-stability polyester industrial yarn comprises a terephthalic acid segment, an ethylene glycol segment and a 2,6-pyridinedicarboxylic acid segment, and 2,6-pyridinedicarboxylic acid segments of different polyester segments are coordinated by Fe.sup.3+, the molar ratio of the terephthalic acid segment to the 2,6-pyridinedicarboxylic acid segment is 1:(0.03-0.05).

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 molecular weight of a semi-crystalline starting polyester comprising ethylene 2,5-furandicarboxylate units is enhanced by heating the semi-crystalline starting polyester, having a melting point Tm, at a temperature in the range of (Tm-40? C.) to Tm to obtain a solid stated polyester, where the semi-crystalline starting polyester has an intrinsic viscosity of at least 0.45 dL/g, and an amount of carboxylic acid end groups in the range of 15 to 122 meq/kg.

The present invention relates to a polycyclohexylenedimethylene terephthalate (PCT) resin having enhanced crystallization speed and a method for preparing same. A PCT resin, according to an embodiment of the present invention, comprises: a reactant of (A) a dicarboxylic acid compound or a dicarboxylic acid ester compound and (B) a diol compound total of which 90 mol % or more is cyclohexanedimethanol; and 10-1000 ppm of antimony (Sb) atoms on the basis of the total weight of the resin, wherein the differential between the melting point (Tm) and a reduced crystallization temperature (Tmc) is 45 C. or lower. A PCT resin, according to the present invention, has high crystallization speed and thus enables fast production of various molded products. In particular, the PCT resin has high crystallization temperature and high heat resistance and thus enables fast production of a high-quality heat-resistant molded product by means of injection molding.

The present invention discloses an ultra-low shrinkage polyester industrial yarn and its preparation method. The ultra-low shrinkage polyester industrial yarn is prepared by subjecting a polyester to dissolution, washing and solid state polycondensation followed by spinning. The ultra-low shrinkage polyester industrial yarn has a dry heat shrinkage rate of 1.80.25% under test conditions of 177 C.10 min0.05 cN/dtex. The polycondensation catalyst consists of magnesium ethylene glycol and antimony ethylene glycol, has a small thermal degradation coefficient. The present invention reduces oligomers during polymerization, reduces thermal degradation during processing, and as a result the invention greatly reduces impurities and nucleating agent in the polyester, leading to an increase in the probability of homogeneous nucleation based on the reduction of heterogeneous nucleation. The dissolution and washing of polyester further decreases oligomer content, facilitating the growth of the grain size and the optimization of crystal perfection in the ultra-low shrinkage polyester industrial yarn.

A low chromatic aberration polyester different-shrinkage composite yarn is made of polyester POY yarn and polyester FDY composite yarn. The polyester POY yarn and polyester FDY yarn is obtained by spinning the polyester solution, the rupture strength of the low color polyester different-shrinkage composite yarn is 1.9 cN/dtex, the elongation at break is 30.05.0%, the crimp shrinkage is 2.503.0%, the network degree is 205/m, the color difference E is less than 0.200. In the invention, the magnesium ethylene glycol is relatively mild, the thermal degradation coefficient is small, the oligomers in the polymerization process is reduced, and the oligomers in the dissolution process are further reduced, so that the appearance of stains and streaks reduces during the dyeing and post-processing heat setting of the polyester fiber, which ensures the fiber's leveling and rubbing fastness.

A polyester-containing object, such as an injection stretch blow molded bottle, a biaxially oriented film or a drawn fiber, is made from melt-processing poly(ethylene-2,5-furandicarboxylate). The poly(ethylene-2,5-furandicarboxylate) has a number average molecular weight of at least 25,000, as determined by GPC based on polystyrene standards, and includes an antimony catalyst.

The present invention discloses an ultra-low shrinkage polyester industrial yarn and its preparation method. The ultra-low shrinkage polyester industrial yarn is prepared by subjecting a polyester to dissolution, washing and solid state polycondensation followed by spinning. The ultra-low shrinkage polyester industrial yarn has a dry heat shrinkage rate of 1.80.25% under test conditions of 177 C.10 min0.05 cN/dtex. The polycondensation catalyst consists of magnesium ethylene glycol and antimony ethylene glycol, has a small thermal degradation coefficient. The present invention reduces oligomers during polymerization, reduces thermal degradation during processing, and as a result the invention greatly reduces impurities and nucleating agent in the polyester, leading to an increase in the probability of homogeneous nucleation based on the reduction of heterogeneous nucleation. The dissolution and washing of polyester further decreases oligomer content, facilitating the growth of the grain size and the optimization of crystal perfection in the ultra-low shrinkage polyester industrial yarn.