Method for synthesizing trimellitic triesters

Abstract

The invention discloses a method for synthesizing trimellitic triesters. The method comprises the following steps: carrying out a methyl esterification reaction on trimellitic anhydride light and heavy components and methanol used as raw materials under the catalysis of a catalyst to generate trimethyl trimellitate, rectifying the trimethyl trimellitate to obtain high-purity and low-color number trimethyl trimellitate, and carrying out ester exchange on trimethyl trimellitate and 2-ethylhexanol, and purifying the obtained ester exchange product to obtain a tri(2-ethylhexyl) trimellitate product. The method has the advantages of effective recycling of the trimellitic anhydride light and heavy components, reduction of generation of pollutants, increase of economic benefits, reduction of the product cost and the environmental protection pressure, low requirements of the content and the color number of the raw material trimellitic anhydride, and realization of high content and low color number of obtained trihexyl ester, and allows the quality of the trihexyl ester to be better than the quality of trihexyl ester obtained through direct esterification of trimellitic anhydride and 2-ethylhexanol.

Description

technical field [0001] The invention belongs to the field of plasticizer production, in particular to a method for producing trimellitate tris(2-ethylhexyl) by using light components and heavy components in the production process of trimellitic anhydride. Background technique [0002] Tris(2-ethylhexyl) trimellitate (TOTM) is a kind of trimellitate ester developed by the United States in the late 1960s. It is a plasticizer with excellent electrical and thermal properties. It has low volatility, good aging resistance, extraction resistance and heat resistance, and good insulation, so it can be used in the production of 105°C heat-resistant cable materials and 10kV PVC cable materials. In addition, it can also be used as an impregnating material for pulse and low-voltage power capacitors and a plasticizer for synthetic leather. In the United States, 78% of TOTM is used in the wire and cable industry, accounting for 13% of the total amount of wire and cable plasticizers, while...

AI Technical Summary

Problems solved by technology

Due to the need to ensure that the content of phthalic anhydride in the trimellitic anhydride product is at an extremely low level in the existing product production method, a large amount of trimellitic anhydride is taken out into the light component during the light removal operation for removing phthalic anhydride; However, when extracting trimellitic anhydride, long-term extraction of trimellitic anhydride at high temperature will lead to carbonization of the material in the kettle, so the extraction time is limited, and there is still a large amount of trimellitic anhydride remaining in the heavy components; these trimellitic anhydrides cannot be rationally utilized, and the treatment of light and heavy components is currently a problem. Difficulties faced by various trimellitic anhydride manufacturers

Due to the existence of a large amount of trimellitic anhydride in the light component, it is extremely difficult to purify the phthalic anhydride in it, and it is difficult to effectively use it. Most of the heavy components are treated as solid waste incineration, causing a lot of waste and increasing the solid waste treatment. quantity