Plastic brightening agent OB and preparation method thereof

Abstract

The invention provides a plastic brightening agent OB. The plastic brightening agent OB is characterized by being prepared from a plastic brightening agent OB crude product, N-methylpyrrolidone and methanol, wherein the plastic brightening agent OB crude product is prepared from the following components in parts by weight: 24-26 parts of thiophene dicarboxylic acid, 45-47 parts of o-amino-p-tert-butylphenol, 123-125 parts of a condensation solvent, 2-3 parts of boric acid, 0.5-0.7 part of a catalyst and 105-110 parts of dimethylformamide; the ratio of the N-methylpyrrolidone to the plastic brightening agent OB crude product in parts by weight is 1-2:1; and the ratio of the methanol to the plastic brightening agent OB crude product in parts by weight is 3-5: 1. According to the plastic brightening agent OB and the preparation method thereof, the production process is rapid and uniform in reaction, free of aggregation, few in impurity, few in by-product and high in purity.

Description

technical field [0001] The invention relates to the technical field of plastic colorants and their preparation, in particular to a plastic brightener OB and a preparation method thereof. Background technique [0002] Fluorescent whitening agents can be regarded as a kind of colorless dyes. After they are dyed on fibers, paper and other substrates, they can absorb ultraviolet rays and emit blue light, thereby offsetting the yellow feeling caused by excessive yellow light reflection on the fabric. It produces white and dazzling effect visually. Different types of fluorescent whitening agents can be used for whitening treatment of various fibers. They are processed directly onto the fabric, where they are fixed to the fibers by self-affinity or cross-linking agents. [0003] Plastic brightener OB, Chinese name: 2.5-bis-(5-tert-butyl-2-benzoxazolyl)thiophene, molecular formula C 26 h 26 N 2 o 2 S, mainly used for whitening PVC, PS, PE, PP, ABS and other plastics. Its struc...

AI Technical Summary

Problems solved by technology

[0005] At present, in the preparation process of plastic brightener OB, the material tends to become very thick during the reaction process, which is difficult to stir, the raw material is wrapped in the material, it is difficult to complete the reaction, and the reaction is difficult to reach the end; the reaction temperature is too high, the side reaction increases, and the product reduced purity

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