Modified polyester, preparation method thereof, and modified polyester film preparation method

Abstract

The invention discloses a modified polyester, a preparation method thereof, and a modified polyester film preparation method, and belongs to the field of polyester. According to the preparation method, spiroglycol and 2, 2-dimethyl-1, 3 propylene glycol are taken as copolymerization modification monomers, direct esterification method is adopted to synthesize a copolyester with a glass-transition temperature higher than 100 DEG C; film prepared of the modified polyester is capable of satisfying battery label film requirements; a tin / phosphorus / antimony composite catalyst is adopted in preparation of the modified polyester; in the esterification period, a tin compound is added as an esterification catalyst; after esterification, a phosphorus compound is added for passivation of the tin catalyst; and a antimony series catalyst is added as a polycondensation catalyst. According to the above steps, the tin compound is capable of achieving catalyst effect on esterification reaction, and yellowing and thermal stability reduction caused by taking the tin compound as a polycondensation catalyst are avoided.

Description

technical field

[0001] The invention belongs to the field of polyester, and in particular relates to a modified polyester and a preparation method thereof and a film preparation method thereof. Background technique

[0002] Shrink film is mainly used for labels and packaging, etc. The materials used to produce shrink film mainly include polyvinyl chloride and polystyrene materials. PVC shrink film has good shrinkage performance, durability, tear resistance, softness, chemical corrosion resistance, transparency and other characteristics, and is widely used in the packaging of beverages and daily necessities. However, PVC materials are not conducive to environmental protection and have been restricted or banned. The polystyrene material is environmentally friendly, and the shrinkage rate can reach 80%. However, the polystyrene label will loosen and fall off when the polystyrene shrink film is bundled and packaged for the second time, which limits its application. PVC, PS mat...