Method for preparing combustion inhibitor bisphenol A bis(diphenyl phosphate)

Abstract

The invention relates to a preparation method for flame retardant bisphenol A bi(diphenyl phosphate). The preparation method comprises the following steps: taking phosphorus oxychloride, bisphenol A and phenol as raw materials, adopting anhydrous zinc chloride or anhydrous aluminum chloride as a main catalyst, and adopting anhydrous calcium chloride or calcium phosphate as a promoter; adding the phosphorus oxychloride, the main catalyst and the promoter into a reactor for intensive stirring, when the materials are heated up to 73 to 78 DEG C, continuously adding bisphenol A, after the addition of bisphenol A is completed within 2.5 to 3 hours, heating up to and maintaining the temperature of 110 to 115 DEG C, and continuing the reaction for 1.5 to 2 hours; leaking out excessive phosphorus oxychloride under the normal and reduced pressure; and cooling down the intermediate product to 100 DEG C, continuous dropping phenol into the intermediate product, heating up to 140 DEG C 2 hours later, carrying out the reaction for 3 to 4 hours, monitoring the content of phenol through the liquid chromatography, and complementing phenol till the phenol content in the crude product is less than 0.5 percent. The yield reaches 98 percent; the content of triphenyl phosphate is less than 1.5 percent; and the acid number is 0.03mgKOH / g.

Description

technical field [0001] The invention relates to a preparation method of polycondensation phosphoric acid ester, in particular to a preparation method of flame retardant bisphenol A bis(diphenyl phosphate). Background technique [0002] Generally, various types of flame retardants are used for flame retardancy of non-combustible plastics, for example, halogen compounds such as decabromodiphenyl ether and tetrabromobisphenol A, phosphorus nitrogen intumescent types such as melamine phosphate and polyphosphate amine and low molecular weight Phosphorus compounds such as triphenyl phosphate and cresyl diphenyl phosphate. [0003] In recent years, as people's awareness of environmental protection has increased, traditional flame retardant materials have been challenged, especially halogenated flame retardants represented by polybrominated diphenyl ethers, which have been severely challenged due to toxicity and corrosion. The resin composition is halogen-free. Phosphate flame ret...

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Problems solved by technology

Japan's Daihachi applied for patent CN1512997 in China. The patent provides phosphorus oxychloride, bisphenol A and phenol as raw materials, and adopts the method of adding bisphenol A at one time. This process is easy in the process of heating up below 70°C. A side reaction occurs, and when the temperature is reached, the reaction is violent again, which is not easy to control, and the amount of phosphorus oxychloride is large, and the recovery consumes a lot of energy

U.S. Patent US2000 / 015598 discloses the synthesis of bisphenol A bis(diphenyl phosphate), the main process is divided into two steps, the first step is to add bisphenol A in batches, the temperature is 85 ~ 105 ° C, and the time is about 3 ~ 6 hours After the reaction is completed, excess phosphorus oxychloride is removed under vacuum; in the second step, melted phenol is added and the temperature of the intermediate is 130-180°C, and the reaction is about 6 hours, and then the phenol is removed in vacuum; the crude product is post-processed to obtain the product, with an acid value of 1.5mgKOH / g, the yield is about 87-92%. The high acid value of the product directly affects the use effect of the product, resulting in mold pollution, etc.

[0005] There are few relevant literature reports on the synthesis of polycondensed phosphate esters in China. The synthesis and application performance of a new phosphorus flame retardant BDP by An Yuhong et al. [J]. Flame Retardant Materials and Technology, 2001, (6) : 11~14; Synthesis of Bisphenol A Phosphate Oligomer Flame Retardants by Wang Xinlong et al [J]. Fine Petrochemical Progress, 2001, 2(5): 11~13; The preliminary laboratory research stage is all one-time adding bisphenol A process, the product content is low, the acid value is high, and the yield is about 85%. At present, there is no set of industrial production equipment in China.

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