Preparation method of plasticizer diethylene glycol dibenzoate

A technology of diethylene glycol dibenzoate and plasticizer, which is applied in the field of preparation of environment-friendly plastic plasticizer diethylene glycol dibenzoate, and can solve the problems of environmental pollution, short reaction time and high reaction temperature , to achieve the effect of shortening the reaction time, increasing the conversion rate and good selectivity

Inactive Publication Date: 2013-05-08
XIAMEN UNIV
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  • Abstract
  • Description
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  • Application Information

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Problems solved by technology

[0004] (1) Transesterification method, Li Lingge et al. Methyl benzoate and diethylene glycol are used as raw materials for transesterification to generate DEDB and methanol. The reaction time of this method is short, and the active ingredient of the plasticizer reaches 99%, but the reaction temperature is higher, and the color is darker and yellowish at the end of the reaction. smell
[0005] (2) Acyl halide method, Wang Shuqing et al. (Wang Shuqing, Sun Dongbing, Gao Chong. Research on the synthesis process of plasticizer diethylene glycol dibenzoate [J]. Plastic Additives, 2010, (03): 23-25) Utilize the action of benzoyl chloride and diethylene glycol to generate DEDB and hydrogen chloride. This method has the advantages of simple process, short reaction time and mild conditions. However, due to the continuous generation of hydrogen chloride gas in the reaction, the corrosion of equipment is relatively serious, and benzene Formyl chloride is relatively expensive for benzoic acid, which limits the industrial application of this method
The traditional method of synthesizing DEDB is to directly esterify diethylene glycol and benzoic acid under the catalysis of sulfuric acid. Direct Catalytic Synthesis of DEDB by Sulfuric Acid
Wang Ying et al. (Wang Ying. Synthesis of diethylene glycol dibenzoate [J]. Journal of Shenyang Institute of Education, 2005, (02):108-110) Catalyzed the reaction of benzoic acid and diethylene glycol with p-toluenesulfonic acid , the post-treatment of the product is complex, requiring neutralization, washing, decolorization and other processes, the discharge of three wastes is large, and the pollution is serious
Zhang Long et al. (Zhang Long, Wang Shujiang, Yang Wenlong, et al. Synthesis of diethylene glycol dibenzoate catalyzed by immobilized heteropolyacid catalyst PW_(12)/C [J]. Petrochemical Industry, 1998, 8) used self-made solid Supported heteropolyacid catalyst PW 12 /C catalyzed the synthesis of DEDB, and the activity of the cata

Method used

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  • Preparation method of plasticizer diethylene glycol dibenzoate
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  • Preparation method of plasticizer diethylene glycol dibenzoate

Examples

Experimental program
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Effect test

Embodiment 1

[0023] Put 122g of benzoic acid and 55.7g of diethylene glycol into a 500ml four-neck flask, the molar ratio of the feed is 2:1.05, heat up, the benzoic acid is completely dissolved, start stirring, add 1.07g of tetrabutyl titanate at 180°C (for the raw material benzene 0.6% of the total mass of formic acid and diethylene glycol), reflux reaction in the temperature range of 160-180°C for 1-1.5h, turn on the vacuum pump, continue to heat up to 200-220°C, keep the reaction under reduced pressure for 2-3h, and steam out after no water Afterwards, stop reaction, obtain DEDB crude product, esterification rate is 98.13%, after 3%Na 2 CO 3 The aqueous solution is neutralized to remove acid, washed with 90°C hot water for 2 to 3 times, the ester layer is separated, and the plasticizer diethylene glycol dibenzoate (DEDB) product is obtained after vacuum distillation and dehydration.

[0024] see figure 2 , with the DEDB standard gas chromatogram (see figure 1 ) comparison, it can b...

Embodiment 2～4

[0026] The operating conditions and steps are the same as in Example 1, the difference is that the molar ratios of benzoic acid and diethylene glycol are (2:1.1), (2:1.15), (2:1.2) respectively, and the amount of catalyst tetrabutyl titanate is equal to It is 0.6% of the total mass of raw materials, and the reaction esterification rates of Examples 2 to 4 are 98.82%, 98.89%, and 99.26%, respectively.

Embodiment 5 and 6

[0028] The operating conditions and steps are the same as in Example 1, the difference is that the molar ratios of benzoic acid and diethylene glycol are (2:1.1) and (2:1.2) respectively, and the catalyst is tin protochloride, and the amount of the catalyst added is the raw material 0.4% of the total mass, the reaction esterification rates of Examples 5 and 6 were 98.16%, 98.46%, respectively.

[0029] see image 3 , with the DEDB standard gas chromatogram (see figure 1 ) comparison, it can be seen that the diethylene glycol dibenzoate (DEDB) product prepared in Example 6 has a high purity and basically no other impurities. The peak with a retention time of 12.78 min on the product chromatogram is a DEDB peak with a retention time of 5.41 min The peak is diethylene glycol monobenzoate peak.

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Abstract

The invention relates to a preparation method of a plasticizer, particularly a preparation method of a plasticizer diethylene glycol dibenzoate, which comprises the following steps: heating benzoic acid and diethylene glycol until the benzoic acid is dissolved, adding a catalyst to carry out reflux reaction, starting a vacuum pump, heating to 200-220 DEG C, keeping the temperature to react under reduced pressure, and stopping the reaction when no water is distilled out, thereby obtaining a diethylene glycol dibenzoate crude product; and cooling the obtained diethylene glycol dibenzoate crude product, neutralizing with an Na2CO3 water solution to remove excessive benzoic acid, washing, separating out the ester layer, and dehydrating by vacuum distillation to obtain a colorless transparent oil liquid which is the plasticizer diethylene glycol dibenzoate product. The technique is simple, does not use any water-carrying agent, continuously distils out water in the reaction under negative pressure, breaks the chemical equilibrium of the esterification reaction, shortens the reaction time, greatly enhances the benzoic acid conversion rate, has the advantages of high esterification rate (up to higher than 98%), favorable catalyst selectivity, fewer side reactions, light product color and no need of activated carbon for decolorization, and is suitable for industrial production and environment-friendly.

Description

technical field [0001] The invention relates to a method for preparing a plasticizer, in particular to a method for preparing an environment-friendly plastic plasticizer, diethylene glycol dibenzoate. Background technique [0002] Plasticizers are one of the plastic additives with the largest production and consumption in the world. Adding them to plastics can increase the plasticity and flexibility of plastics. Due to the fact that the traditional plasticizer dioctyl phthalate (DOP) has been approved by the American Cancer Institute (NCI) suspected carcinogenic effect, its scope of use was greatly restricted. Compared with DOP, diethylene glycol dibenzoate (DEDB) has the characteristics of good compatibility, good cold resistance, antistatic property, remarkable anti-pollution performance, outstanding thermal stability, low volatility, and good photochromic resistance. , and low toxicity, it is an environmentally friendly plasticizer, an ideal substitute for DOP, and has a...

Claims

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Application Information

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IPC IPC(8): C07C69/78C07C67/08
Inventor 郑艳梅曾纯李清彪何宁孙道华王远鹏黄加乐景孝廉
Owner XIAMEN UNIV
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