Preparation method of polyester chip for thick membrane with thickness of more than 150mum

Abstract

The invention provides a preparation method of a polyester chip for a thick membrane with the thickness of more than 150mum. The preparation method which allows a polyhydroxy organic matter, an anti-bonding agent, a stabilizing agent and a catalyst to be added to one or more of diacids and one or more of dihydric alcohols which are treated as main raw materials is characterized in that: a direct esterification process is adopted, an esterification reaction is carried out for 1-3h under conditions of a temperature of 210-270DEG C and a pressure of 0.1-0.5MPa, and a polycondensation reaction is carried out for 1.5-3h under conditions of a temperature of 250-290DEG C and a pressure of equal to or less than 1KPa, the polyhydroxy organic matter is added when the esterification reaction is ended, and the polyester chip is obtained by granulating and drying after finishing the polycondensation reaction. The polyester chip has a slow crystallization rate, and when the membrane with the thickness of more than 150mum is processed from the polyester chip of the invention, casting chips do not become white and there is no need to add anti-bonding masterbatch chips; present routine production equipment can be adopted to directly produce the thick membrane; and performances of the thick membrane are excellent, and phenomena of large crystallization degree and much membrane rupture, which appear when super-bright polyester chips are used to produce the thick membrane, do not appear in the invention.

Description

technical field

[0001] The invention relates to the synthesis and processing of polyester chips, in particular to a method for preparing polyester raw material chips suitable for producing films with a thickness of more than 150 μm, and belongs to the technical field of polymer chemical industry. Background technique

[0002] Biaxially oriented polyethylene terephthalate film (BOPET for short) has excellent physical and chemical properties and can be widely used in many industrial fields.

[0003] With the rapid development of the home appliance industry, my country's demand for thick polyester film (hereinafter referred to as thick film) has increased significantly. At present, most of the film specifications produced by the domestic BOPET double-drawing production line are in the range of 8-75 μm, and the production capacity in this range has far exceeded the demand. However, thick films of 150-300 μm have considerable room for development, especially the application rang...

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