Preparation method for tert-carbonic acid glycidyl ester

Abstract

The invention provides a preparation method for tert-carbonic acid glycidyl ester. The tert-carbonic acid glycidyl ester is synthesized through two steps, i.e., a first step of subjecting tert-carbonic acid and a halogenated epoxy compound to a reaction under the action of a catalyst to produce tert-carbonic acid halohydrin ester and a second step of removing halogen hydride from the tert-carbonic acid halohydrin ester to form the tert-carbonic acid glycidyl ester, wherein in the first step of synthesis of the tert-carbonic acid halohydrin ester, the tert-carbonic acid reacts with the halogenated epoxy compound only in the presence of water and the catalyst and the water comprises water added in the reaction in advance. With the preparation method provided by the invention, product output per unit volume can be substantially increased, and the method is especially applicable to large-scale industrial production of tert-carbonic acid glycidyl ester with low cost, high purity and a light and stable color.

Description

technical field [0001] The invention relates to the field of organic compound synthesis, in particular to a synthesis method of glycidyl tertiary carbonic acid ester. Background technique [0002] Glycidyl tertiary carbonic acid ester is a highly branched, glycidyl ester of monobasic saturated fatty acid with α-branch (also known as glycidyl ester of branched carboxylic acid). This product can be used to prepare acrylic series modified resins, polyester modified resins, alkyd modified resins and epoxy resins, and can also be used as a reactive diluent for paints, etc. It can significantly enhance the performance of paints and is a high-quality automotive An important raw material for paints, coil coatings and metallic coatings. [0003] In the prior art, a tertiary carbonic acid is reacted with a halogen-substituted monoepoxide to prepare a tertiary carbonic acid glycidyl ester. Basically, a two-step method is adopted, that is, the first step is to synthesize a tertiary car...

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Problems solved by technology

The amount of water used in this step is relatively large (the total amount of water is 4-13 times the molar amount of carboxylic acid), and because the concentration of brine formed after the reaction is relatively low, it is inevitable to take away part of the solvent and halogenated epoxy when separating the first step brine. Propane and formed products into dilute brine, resulting in loss of the solvent, halopropylene oxide and products

If the organic matter in the above-mentioned dilute brine is reclaimed, on the one hand, it is possible to cause final loss of raw materials and products due to the incomplete recovery of the solvent and the difficult recovery of the halogenated propylene oxide and the product formed; on the other hand, Among them, the halogenated propylene oxide and the formed products that cannot be recovered will form wastewater or solid waste, which will have an impact on the environment

[0008] 2. Example 1 of this patent shows that the amount of isopropanol used in the first step of catalytic synthesis is relatively large, accounting for about 35% of the total reaction volume, which will cause a substantial decline in the output per unit reaction volume, which is not conducive to large-scale Large-scale industrial production

At the same time, isopropanol and halogenated propylene oxide will also produce side reactions, which will cause unnecessary loss of halogenated propylene oxide

[0009] 3, when this method is added alkali dehydrohalogenation for the first time, because have halogenated propylene oxide to exist, can produce side reaction, make halogenated propylene oxide produce unnecessary loss, thereby reduced the rate of recovery of this raw material; At the same time, it also led to the increase of high boiling point by-products, which made the product quality decline.

[0010] 4. In the first dehydrohalogenation of this method, the amount of epichlorohydrin present in the reaction accounts for about 23% of the total reaction volume, which also makes the output per unit reaction volume drop significantly, which is not conducive to large-scale industrial production

[0011] 5, when this method distills and reclaims halogenated propylene oxide and the solvent that can be miscible with water, not only because of the aforementioned reasons, the rate of recovery of this solvent and halogenated propylene oxide has decreased, and what obtains is a mixed solvent, which does not Good for recycling

[0012] 6. Because the first dehydrohalogenation reaction is not complete in this method, the second dehydrohalogenation must be used

This method adopts quaternary ammonium salt as catalyst, and there are some defects equally: first quaternary ammonium salt can form the alkali metal hydroxide and alkali metal salt etc. The lipid ammonium ions are brought into the organic phase, resulting in the emulsification of glycidyl esters; secondly, the lipophilic ammonium ions can also bring organic matter into the water phase through the action of charges, resulting in an increase in the COD value of wastewater, resulting in increased environmental pollution and product degradation. loss

In order to solve the above-mentioned problems, the glycidyl tertiary carbonic acid ester that is synthesized must be carried out to rectification purification and separation. In this process, because of the thermal reactivity of the glycidyl tertiary carbonic acid ester, it will inevitably lead to a decrease in the synthesis yield. decline

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