A kind of polyester catalyst and its preparation method and application

Abstract

The invention relates to a polyester catalyst, and a preparation method and application thereof. The polyester catalyst is a homogeneous phase solution prepared by mixing and reacting one of stibium compounds, binary organic acids or glycol esters, lactic acid and ethylene glycol; the stibium content in the polyester catalyst is 2.0-6.0%; and the polyester catalyst is in a liquid state at normal temperature, and can be directly used for polyester polycondensation reaction. The synthesis technique is simple and easy to operate and low in cost, can omit the heating conditioning and insulating process when using a solid stibium catalyst, is quick and convenient to use, and lowers the polyester production cost.

Description

technical field [0001] The invention relates to a catalyst for synthesizing polyester (polyethylene terephthalate, referred to as PET) and its preparation method and application technology field. More specifically, the antimony compound is combined with a modifier and dissolved in ethyl In the diol, a liquid antimony catalyst that does not crystallize out at normal temperature is prepared, and the catalyst is used in the field of polyester synthesis. Background technique [0002] At present, the commonly used catalysts in PET production are solid antimony trioxide, crystal antimony acetate or crystal ethylene glycol antimony, wherein antimony acetate and ethylene glycol antimony are reacted by antimony trioxide with acetic anhydride and ethylene glycol respectively, and crystallized, Separation, drying and other processes, when using the above three solid compounds as catalysts to synthesize polyester, it needs to be reheated and dissolved in ethylene glycol, and kept warm f...

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Problems solved by technology

Its disadvantages are: 1. Since antimony trioxide, crystal antimony acetate or crystal ethylene glycol antimony are insoluble in ethylene glycol at room temperature, they need to be heated and cooked to dissolve, and antimony acetate and ethylene glycol antimony catalysts are in the process of preparation. Has gone through processes such as heating and dissolving, crystallization, separation, drying, etc., and needs to be reheated and dissolved when used in polyester synthesis. Therefore, there are defects such as high energy consumption and high cost in the manufacture and use of catalysts in the prior art; 2. During the dissolution process , solid-state antimony trioxide, antimony acetate, and antimony glycol are easy to deposit in the dissolution equipment, and local overheating disproportionation and decomposition will turn yellow and black, resulting in a decrease in catalytic activity and residual toxicity in polyester exceeding Sb 3+ Sb 0 And affect the quality of polyester; 3. It is easy to crystallize and precipitate after heating and dissolving, which brings inconvenience to the application. In order to prevent crystallization, the concentration of antimony generally needs to be controlled below 1%, and the temperature needs to be maintained at 90~120°C; 4. Dissolution The final antimony catalyst is placed at high temperature for a long time, which not only wastes energy, but also is prone to disproportionation reaction, resulting in reduced catalytic activity, etc.

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