Method for manufacturing directly-spun PET (polyethylene glycol terephthalate) polyester staple fibers by aid of titanium catalysts

Abstract

The invention discloses a method for manufacturing directly-spun PET (polyethylene glycol terephthalate) polyester staple fibers by the aid of titanium catalysts. The method includes steps of continuously adding the titanium catalysts blended in EG (ethylene glycol) during esterification reaction and pre-polycondensation reaction by the aid of direct spinning processes; adding ultraviolet transforming agents, phosphorus stabilizers and extinction agents; carrying out final polycondensation reaction, direct spinning and afterfinish to obtain the directly-spun PET polyester stable fibers. The method has the advantages that the titanium catalysts are simultaneously added in esterification reaction and polycondensation reaction working procedures by the aid of the direct spinning processes, bis-styrene heterocyclic ring compounds which do not participate in polyester synthetic reaction but can effectively convert ultraviolet rays into blue visible light are added in the esterification reaction and polycondensation reaction working procedures, the phosphorus stabilizers are added simultaneously, accordingly, the temperatures can be reduced by 1-5 DEG C in the integral reaction procedures as compared to antimony catalysts, the addition amounts of the titanium catalysts can be reduced, apparent color values b can be reduced, and the mechanical performance of the stable fibers can be improved.

Description

technical field [0001] The patent of the present invention relates to the field of textiles, in particular to a method for producing PET polyester direct spinning staple fibers using a titanium-based catalyst. Background technique [0002] The synthesis process of large-scale industrialized (above 100 tons / day) PET polyester staple fibers usually uses antimony (Sb) series catalysts as polycondensation catalysts, uses refined PTA (PTA) and EG (EG) as raw materials, and undergoes esterification ( Esterification) and polycondensation (Polycondensation), adding antimony (Sb) catalysts (such as antimony trioxide, EG antimony or antimony acetate, etc.) The polymer is transported to the spinning through the pipeline; the tow is cooled by the lateral quenching air, and the tow is stretched, shaped, crimped and cut to obtain short fibers. [0003] According to incomplete statistics, by the end of 2013, the global PET polyester production capacity was 72 million tons, of which polyes...

AI Technical Summary

Problems solved by technology

[0012] The most notable advantages of using titanium-based catalysts in direct esterification and continuous polycondensation PET synthesis industry are environmental protection, safety, and efficiency improvement, as well as the relatively large reduction in the temperature of the synthesis and spinning process and energy consumption; It can make the melt cleaner, make the physical and mechanical properties of the fiber more uniform, greatly improve the stability of the production process, and reduce the material consumption; but there are also several difficult problems to overcome, one is the b value of solid PET The second is that the macromolecular degradation rate of solid PET in the dry melt spinning process is more than 1 times higher than that of antimony-based catalysts. Under the same molecular weight conditions, the physical and mechanical properties of the fiber are relatively low

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