A kind of method for transesterification continuous reaction to prepare higher carbon alcohol phthalate

Abstract

The invention relates to a method for preparing higher alcohol phthalate through continuous transesterification reaction. In a fixed-bed reactor, dimethyl phthalate, diethyl phthalate, diphthalate Low-carbon alcohols such as butyl phthalate and high-carbon alcohols such as isononanol, isodecyl alcohol, and 2-propylheptanol are used as raw materials, and magnesium calcium aluminate, sodium aluminosilicate, potassium aluminosilicate, silicon One or more of magnesium aluminate, calcium aluminosilicate, aluminum magnesium titanate, magnesium calcium titanate, and aluminum magnesium zirconate are catalysts, and the molar ratio of higher alcohol to lower alcohol phthalate is 2.1-4.0 , reaction temperature 160~220℃, volume space velocity 0.5~2h ‑1 , The conversion rate of low-carbon alcohol phthalate and the selectivity of high-carbon alcohol phthalate are above 99%. The invention has the following advantages: good stability of raw material storage and transportation, convenient feeding; less side reactions, low raw material consumption; no corrosion of the catalyst and continuous use; clean and energy-saving process, no waste water generation and discharge; reaction in a fixed bed reactor Continuous, high efficiency.

Description

technical field [0001] The invention belongs to the field of organic chemical industry, and in particular relates to a method for preparing higher-carbon alcohol phthalate through continuous transesterification reaction. Background technique [0002] Plasticizers are necessary additives for the production of polyester, plastic and rubber products. They are used to weaken the force between polymers, increase the mobility of molecular chains, and reduce crystallinity, thereby improving the plasticity, flexibility and tension of polymers. Comprehensive properties such as elongation. my country mainly uses low-end plasticizers such as dibutyl phthalate (DBP for short) and dioctyl phthalate (DOP for short), which are easy to migrate and precipitate, and have great environmental impact. DBP, DOP, etc. have been restricted in production and use in Japan, the United States, the European Union and other places, and have been mainly used by Diisononyl Phthalate (DINP for short), Dide...

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Problems solved by technology

[0006] In order to solve the problem of poor storage and transportation stability of raw material phthalic anhydride in the process of preparing DINP, DIDP, DPHP and other high-carbon alcohol ester plasticizers by phthalic anhydride esterification method, inconvenient feeding, and strong irritation to human body; many side reactions, The consumption of raw materials is high; the catalyst is highly corrosive and cannot be recycled, and needs to be removed by processes such as alkali washing and water washing, resulting in a large amount of waste water; the reaction is a gap reaction and low efficiency. The purpose of the invention is to develop a continuous transesterification reaction The method for preparing higher alcohol phthalates such as DINP, DIDP, DPHP has the following advantages: (1) adopt dimethyl phthalate, diethyl phthalate, dibutyl phthalate etc. Phthalic acid low-carbon alcohol ester replaces phthalic anhydride as raw material, which has good storage and transportation stability and convenient feeding; (2) High-carbon alcohol phthalic acid ester is prepared by transesterification method, and the reaction is anhydrous, which can not only reduce water separation Energy consumption, and can avoid the production and discharge of process wastewater; (3) The transesterification catalyst researched and developed is non-corrosive and can be used continuously, with less side reactions and low raw material consumption; (4) The reaction is carried out continuously in a fixed-bed reactor ,efficient

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