阅读说明：本技术 一种四溴双酚a双烯烷基醚的制备方法 (Preparation method of tetrabromobisphenol A diene alkyl ether ) 是由 王艳红 孙仿建 于 2021-10-07 设计创作，主要内容包括：本发明公开了一种四溴双酚A双烯烷基醚中间体的制备方法,是在甲醇钠的甲醇溶剂体系中,以四溴双酚A与氯代烯烷烃进行无水环境下的威廉姆斯醚化反应,制备得到相应的四溴双酚A双烯烷基醚中间体。本发明使用甲醇钠代替氢氧化钠在甲醇溶液中反应,使后续威廉姆斯醚化反应在无水甲醇溶液中进行,避免了一系列的水解副反应和单取代副反应,最终制备八溴双酚醚类阻燃剂的含量和熔点都得到了一定的提高。(The invention discloses a preparation method of a tetrabromobisphenol A diene alkyl ether intermediate, which is characterized in that tetrabromobisphenol A and chloroalkene alkane are subjected to Williams etherification reaction in an anhydrous environment in a methanol solvent system of sodium methoxide to prepare the corresponding tetrabromobisphenol A diene alkyl ether intermediate. According to the invention, sodium methoxide is used for replacing sodium hydroxide to react in a methanol solution, so that the subsequent Williams etherification reaction is carried out in an anhydrous methanol solution, a series of hydrolysis side reactions and single substitution side reactions are avoided, and the content and the melting point of the finally prepared octabromo bisphenol ether flame retardant are improved to a certain extent.)

1. Tetrabromobisphenol A diene alkyl ether is prepared by carrying out Williams etherification reaction on tetrabromobisphenol A and chloroalkene alkane in a methanol solvent system of sodium methoxide under anhydrous environment to obtain a corresponding tetrabromobisphenol A diene alkyl ether intermediate.

2. The method for preparing tetrabromobisphenol A diene alkyl ether according to claim 1, wherein solid sodium methoxide is dissolved in solvent methanol, tetrabromobisphenol A is added and completely dissolved, chloroalkene alkane is dripped at 10-35 ℃ to carry out Williams etherification, and reaction products are filtered out to obtain a corresponding tetrabromobisphenol A diene alkyl ether intermediate.

3. The method for preparing tetrabromobisphenol A diene alkyl ether according to claim 2, wherein chloroalkene alkane is added dropwise into the reaction system within 2 hours, and etherification reaction is continued for 5-8 hours after chloroalkene alkane is added dropwise.

4. The process of claim 2, wherein the filtered reaction product is washed with water and dried to obtain tetrabromobisphenol A diene alkyl ether intermediate.

5. The process for producing tetrabromobisphenol A diene alkyl ether according to claim 1 or 2, wherein said chloroalkenealkane is propylene chloride or isobutylene chloride.

Technical Field

The invention belongs to the technical field of preparation of flame retardants, and relates to a preparation method of tetrabromobisphenol A diene alkyl ether serving as an intermediate for producing octabromobisphenol ether flame retardants.

Background

The octabromo bisphenol ether compound is a white powder, has low toxicity, is soluble in benzene, acetone, chloroform, etc., is insoluble in water and hexanol, and has decomposition temperature higher than 285 deg.C. As a main product of tetrabromobisphenol A deep processing, the octabromobisphenol ether compound is a high-efficiency flame retardant simultaneously containing aromatic bromine and aliphatic bromine, has better flame retardant effect and excellent thermal stability and light stability when being used as an additive flame retardant, and is mainly used for the production of resins such as polypropylene, polyethylene, polyvinyl chloride and the like.

At present, the market occupancy rate of octabromo bisphenol ether flame retardants is rapidly increasing, because by the end of 2021, hexabromo cyclododecane, a product of which the domestic flame retardant share is large, stops producing due to the limitation of Stockholm treaty, and the market vacancy is replaced by octabromo bisphenol ether flame retardants which have higher decomposition temperature and better performance but higher selling price.

Taking the main variety of octabromoether of octabromobisphenol ether flame retardant as an example, the current domestic main synthesis process is to dissolve tetrabromobisphenol A as a raw material in methanol, add solid alkali with calculated amount to generate disodium salt of tetrabromobisphenol A and water, then drop propylene chloride into the aqueous methanol solution at 20 ℃, after dropping for about 1h, raise the temperature to 50 ℃ and continue to react for 6 h. And cooling to 5 ℃ after the reaction is finished, filtering out tetrabromobisphenol A-diallyl ether precipitate containing sodium chloride, washing out the sodium chloride in the tetrabromobisphenol A-diallyl ether precipitate by using warm water, and drying to obtain an octabromoether intermediate, namely tetrabromobisphenol A-diallyl ether, of which the water content is less than 0.2%.

In the above synthesis process, tetrabromobisphenol A is reacted with sodium hydroxide in methanol to produce tetrabromobisphenol A sodium salt and water, and the Williams etherification reaction is carried out in an aqueous methanol solution, so that many side reactions such as hydrolysis of propylene chloride to produce acrylic acid, reaction of acrylic acid with methanol to produce ester, incomplete reaction of propylene chloride to produce monoether, self-polymerization of acrylic acid, and the like are inevitable. The impurities generated by the series of byproducts can be brought into the final octabromoether product, so that the melting point of the product is reduced, and poor quality defects are generated.

Therefore, the content of octabromoether prepared by the existing domestic synthesis process is generally 97-98%, the melting point is 100 ℃, and the synthesis process has a great promotion space so as to improve the quality of octabromoether products.

Disclosure of Invention

The invention aims to provide a preparation method of a tetrabromobisphenol A diene alkyl ether intermediate, which is used for reducing side reactions possibly generated in the preparation of the intermediate and improving the product quality of an octabromobisphenol ether flame retardant.

The preparation method of tetrabromobisphenol A diene alkyl ether comprises the step of carrying out Williams etherification reaction on tetrabromobisphenol A and chloroalkene alkane in a methanol solvent system of sodium methoxide in an anhydrous environment to prepare a corresponding tetrabromobisphenol A diene alkyl ether intermediate.

Further, the tetrabromobisphenol A diene alkyl ether is more specifically prepared by dissolving solid sodium methoxide in a solvent methanol, adding tetrabromobisphenol A to completely dissolve, dropwise adding chloroalkenealkane at 10-35 ℃ to perform Williams etherification reaction, and filtering a reaction product to obtain a corresponding tetrabromobisphenol A diene alkyl ether intermediate.

Furthermore, the chloroalkenealkane is dropwise added into the reaction system within 2 hours, and the chloroalkenealkane is continuously etherified for 5-8 hours after dropwise addition.

Further, the reaction product filtered out is washed repeatedly with water and then dried to obtain the tetrabromobisphenol A diene alkyl ether intermediate.

In the above preparation method of the present invention, the chloroalkene may be propylene chloride or isobutylene chloride, and thus, an intermediate tetrabromobisphenol a-diallyl ether or tetrabromobisphenol a-diisobutylene ether may be prepared respectively.

Furthermore, the raw material for carrying out the Williams etherification with tetrabromobisphenol A in the present invention is not limited to chloroalkene alkane, but may be a raw material for preparing other octabromobisphenol ether-based flame retardants or tetrabromobisphenol-based flame retardants. Tetrabromobisphenol A-hydroxyethyl ether can be produced, for example, by Williams etherification of tetrabromobisphenol A with chloroethanol.

According to the preparation method of the tetrabromobisphenol A diene alkyl ether intermediate, sodium methoxide is used for replacing sodium hydroxide to react in a methanol solution, sodium salt and methanol of tetrabromobisphenol A are firstly generated, and further Williams etherification reaction is carried out on the sodium salt and chloroalkenealkane in an anhydrous methanol solution, so that a series of hydrolysis side reactions are avoided, the etherification reaction is carried out more thoroughly, and a single substitution side reaction is basically avoided.

Compared with the existing domestic synthesis process, the content and the melting point of the octabromo bisphenol ether flame retardant prepared by the method are improved to a certain extent, the content can reach more than 99 percent, the melting point is more than 100 ℃, and the product quality of the octabromo bisphenol ether flame retardant is improved.

Detailed Description

The following examples are given to further illustrate the embodiments of the present invention. The following examples are only for more clearly illustrating the technical solutions of the present invention so as to enable those skilled in the art to better understand and utilize the present invention, and do not limit the scope of the present invention.

The names and the abbreviations of the experimental methods, production processes, instruments and equipment related to the embodiments of the present invention are all conventional names in the art, and are clearly and clearly understood in the related fields of use, and those skilled in the art can understand the conventional process steps and apply the corresponding equipment according to the names, and implement the process according to the conventional conditions or the conditions suggested by the manufacturers.

The raw materials and reagents used in the examples of the present invention are not particularly limited in terms of their sources, and are all conventional products commercially available. They may also be prepared according to conventional methods well known to those skilled in the art.

Example 1.

300kg of methanol was charged into a 1000L reactor, and 30kg of solid sodium methoxide was added thereto with stirring and stirred until the methanol was completely dissolved.

140kg of tetrabromobisphenol A was added to the reaction vessel, and the mixture was stirred until it was completely dissolved.

At the temperature of 35 ℃, 55kg of propylene chloride is dropwise added into the reaction kettle within 2h, and then the reaction is continuously stirred for 8 h.

After the reaction is finished, cooling the reaction solution to 5 ℃, and filtering.

Washing the filter cake with 150kg of 15 ℃ deionized water for multiple times, and drying to obtain an intermediate product tetrabromobisphenol A-diallyl ether, wherein the product yield is 98.1%, the content is 99.6%, and the melting point is 100 ℃.

Comparative example 1.

A1000 mL three-necked flask was charged with 300g of methanol, and 21.3g of solid sodium hydroxide was added with stirring and stirred until the total amount was dissolved.

140g of tetrabromobisphenol A were added to the three-necked flask and the mixture was stirred until completely dissolved.

55g of propylene chloride was added dropwise in 2h to a three-necked flask at 35 ℃ under control, and the reaction was then continued with stirring for 8 h.

After the reaction is finished, cooling the reaction solution to 5 ℃, and filtering.

Washing the filter cake with 150g of deionized water at 15 ℃ for multiple times, and drying to obtain an intermediate product tetrabromobisphenol A-diallyl ether, wherein the product yield is 97.1%, the content is 97.25%, and the melting point is 94.9 ℃.

Example 1 is applied.

1150kg of methylene chloride was charged into a 2000L reactor, and 400kg of tetrabromobisphenol A-dipropylene ether prepared in example 1 was added with stirring and stirred until all was dissolved.

192kg of bromine was slowly added dropwise over 2h at 20 ℃ for bromination.

After the reaction is finished, a little sodium sulfite is added to ensure that the potassium iodide starch test paper does not develop color.

The reaction was heated to 50 ℃ and concentrated to remove most of the methylene chloride, then cooled to 5 ℃, filtered and dried to prepare octabromoether (CAS:21850-44-2), tested for product melting point 105 ℃.

Example 2.

330kg of methanol was added to a 1000L reaction vessel, and 30kg of solid sodium methoxide was added thereto with stirring and stirred until the solid sodium methoxide was completely dissolved.

140kg of tetrabromobisphenol A was added to the reaction vessel, and the mixture was stirred until it was completely dissolved.

At 25 ℃, 64kg of isobutene chloride is dropwise added into the reaction kettle within 2h under control, and then the stirring reaction is continued for 6 h.

After the reaction is finished, cooling the reaction solution to 5 ℃, and filtering.

Washing the filter cake with 150kg of 10 ℃ deionized water for multiple times, and drying to obtain an intermediate product tetrabromobisphenol A-bis-isobutylene ether, wherein the yield of the product is 98.25%, the content is 99.41%, and the melting point is 105 ℃.

Comparative example 2.

A1000 mL three-necked flask was charged with 330g of methanol, and 24g of solid sodium hydroxide was added with stirring and stirred until all dissolved.

140g of tetrabromobisphenol A were added to the three-necked flask and the mixture was stirred until completely dissolved.

At 25 ℃, 64g of isobutene chloride is added dropwise into a three-necked flask within 2h under control, and then the reaction is continued to be stirred for 6 h.

After the reaction is finished, cooling the reaction solution to 5 ℃, and filtering.

Washing the filter cake with 150g of 10 ℃ deionized water for multiple times, and drying to obtain an intermediate product tetrabromobisphenol A-bis-isobutylene ether, wherein the product yield is 97.62%, the content is 96.78%, and the melting point is 95 ℃.

Example 2 is applied.

450kg of methylene chloride was charged into a 1000L reaction vessel, and 210kg of tetrabromobisphenol A-diisobutylene ether prepared in example 2 was added with stirring and stirred until all was dissolved.

At 25 ℃, 99kg of bromine is slowly added dropwise in 2 hours for bromination reaction.

After the reaction is finished, a little sodium sulfite is added to ensure that the potassium iodide starch test paper does not develop color.

The reaction was heated to 52 ℃ and concentrated to remove most of the methylene chloride, then cooled to 5 ℃, filtered and dried to prepare methyl octabromo ether (CAS:97416-84-7), the melting point of which was determined to be 110 ℃.

Example 3.

300g of methanol was added to a 1000mL three-necked flask, and 29g of solid sodium methoxide was added thereto with stirring and stirred until the total amount was dissolved.

138g of tetrabromobisphenol A were added to the three-necked flask, and the mixture was stirred until completely dissolved.

At 25 ℃, 48g of chloroethanol is dropwise added into a three-necked bottle within 2h under control, and then the reaction is continuously stirred for 8 h.

After the reaction is finished, cooling the reaction solution to 5 ℃, and filtering.

The filter cake is washed by 150g of deionized water with the temperature of 10 ℃ for a plurality of times and then dried to obtain an intermediate product tetrabromobisphenol A-bis hydroxyethyl ether, the yield of the product is 97.91 percent, and the content is 99.38 percent.

The above embodiments of the present invention are not intended to be exhaustive or to limit the invention to the precise form disclosed. Various changes, modifications, substitutions and alterations to these embodiments will be apparent to those skilled in the art without departing from the principles and spirit of this invention.