Preparation method for diisononyl cyclohexane-1,2-dicarboxylate

Abstract

The invention provides a preparation method for diisononyl cyclohexane-1,2-dicarboxylate. The preparation method comprises the following steps: 1) adding hexahydrophthalic anhydride, isononanol and acetic anhydride into a reaction vessel at the same time, carrying out heating to 180 to 300 DEG C and then carrying out stirring and dehydration for 2 to 5 h, wherein a mol ratio of hexahydrophthalic anhydride to isononanol is 1: (2-5), and the addition amount of acetic anhydride is 1 to 10% of the mass of hexahydrophthalic anhydride; 2) removing excess alcohol through flash evaporation by using a falling-film evaporator at a negative pressure of -0.02 MPa to 0.096 MPa, wherein retention time is 0.001 to 0.05 h; 3) introducing water vapor and nitrogen into a stripping tank for bubbling and removing low-molecular-weight impurities in a material 2 through evaporation; and 4) adding active carbon accounting for 1 to 10% of the mass of a material 3 into a decoloring kettle and carrying out decoloring and filtering so as to obtain the final product diisononyl cyclohexane-1,2-dicarboxylate, wherein yield reaches 98.5% and purity reaches 99.8%. According to the invention, a single-step high-temperature esterification process is employed, so reaction time is greatly shortened; excess alcohol is removed through pressure-reduced flash evaporation, so energy consumption is lowered, and the phenomenon of emulsification is avoided; and neutralization and washing are not needed, so alkaline waste water is not produced, and the preparation method is suitable for large-scale industrial production.

Description

technical field [0001] The invention belongs to the field of fine chemicals, and is a novel method for preparing a new environment-friendly plasticizer, diisononyl cyclohexane-1,2-dicarboxylate. Background technique [0002] Diisononyl cyclohexane-1,2-dicarboxylate (alias: diisononyl hexahydrophthalate, abbreviation: DINCH) is an emerging safe and environmentally friendly plasticizer, which has the same properties as diisophthalate Nonyl ester (DINP) and dioctyl phthalate (DOP) have similar structures and properties, and are mainly used in: medical drugs, food packaging, children's toys and child care products, and more importantly, their plasticized products are naturally It can be biodegraded in the environment by itself, does not cause environmental pollution, is beneficial to human health and safety, and is a good substitute for benzenecarboxylate plasticizers. Therefore, it has become a general trend to develop new products of high-efficiency, non-toxic and degradable ...

AI Technical Summary

Problems solved by technology

The domestic device borrows from the single-step high-temperature esterification method of CN1962736, which greatly shortens the reaction time, but first neutralizes and then dealcoholizes, which consumes a lot and the ester and water are easy to emulsify, which is not conducive to stratification, and the product has high chroma

With the stringent environmental protection requirements, a large amount of neutralization and washing wastewater has also added a great burden to the enterprise

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