Preparation method of phthalate plasticizer

Abstract

The invention provides a preparation method of a phthalate plasticizer. The method specifically comprises the steps of esterification, crude dealcoholization, cooling, addition of a deacidifying agent, dealcoholization and filtration. The preparation method is adopted; treatment is carried out without a decolorizing agent, the chromaticity of the prepared phthalate plasticizer product can reach 10-15 # through platinum-cobalt standard colorimetry; phthalic anhydride and sec-octyl alcohol are used as raw materials; the acid value of the dioctyl phthalate prepared by the preparation method disclosed by the invention is less than or equal to 0.05 mgKOH / g; wherein the water content is less than or equal to 0.05%, the alcohol content is more than or equal to 99.5% and the alcohol content is less than or equal to 0.005%, and meanwhile, neutralizing and washing steps can be reduced, the wastewater amount is reduced, the alkali washing, washing and settling time is saved, the production cost is greatly reduced and the production benefit is increased.

Description

technical field [0001] The invention belongs to the technical field of fine chemicals, and in particular relates to a preparation method of a phthalate plasticizer. Background technique [0002] Plasticizers are widely used in the field of plastic product processing. With the rapid development of the plastics industry, higher requirements are placed on the quality of plasticizers, especially in the control of the color of plasticizer products. The color of plasticizer products and The transmittance and refractive index of downstream products are closely related. At present, the preparation process of plasticizer is mainly decolorization with decolorizing agent. As the most widely used decolorizing agent, activated carbon has low price, mature application technology, and good decolorization effect. It is used in decolorization of plasticizer and other decolorization and adsorption fields. [0003] However, activated carbon is used in a large amount during use, and activate...

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Problems solved by technology

[0003]However, activated carbon is used in a large amount during use, and activated carbon will absorb a large part of plasticizer materials, resulting in a large waste of materials, and activated carbon has limited adsorption capacity, and colored substances can not be completely absorbed

Although activated carbon has many advantages as a decolorizer, it also has many defects. It is of positive significance to study a production process that can effectively remove the color of plasticizer products.

[0004]CN201510846882.8 discloses a production process of dibutyl phthalate plasticizer, the esterification reaction is carried out with phthalic anhydride, n-butanol and solid acid catalyst, and the reaction ends , filter out the solid catalyst, and after neutralization, water washing, stripping, and fine filtration, dibutyl phthalate plasticizer products are obtained, but diatomaceous earth and activated carbon must be added to the refined ester for decolorization. A ton of product will generate 4-6 kg of solid waste, which is difficult to recycle and costly to process

[0005]CN200610085456.8 discloses a production process of esterification of phthalic acid esters, which uses phthalic anhydride and corresponding excess alcohols as raw materials to prepare monoesters, and then Add aluminum oxide solid and sodium hydroxide aqueous solution to heat to form sodium aluminate, add lithium hydroxide to the sodium aluminate to catalyze the diester reaction, improve the quality of the finished product of dioctyl phthalate, and obtain a product with a color in the 10-20 APHA, in fact, this kind of lithium-containing catalyst is expensive and used in a large amount, so it is not suitable for industrial production

[0006] CN200510017105.9 discloses a production method of diisodecyl phthalate, which uses phthalic anhydride and isodecyl alcohol as raw materials, and titanic acid Using isopropyl ester as a catalyst, after esterification, dealcoholization, alkali washing and water stripping, the prepared diisodecyl phthalate has a chroma of 30~15# by platinum-cobalt standard colorimetry, and an ester content of 99.8~ 99.9%, but the preparation process needs to add activated carbon for decolorization, resulting in hazardous waste of activated carbon, and it needs to be washed repeatedly with alkali and water, which will generate a lot of waste water, increase the amount of waste water, and increase the production cost

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