[Background and Overview][1][2]
Phenol and isobutylene (or tert-butyl alcohol) are prone to alkylation in the presence of acidic catalysts to produce tert-butylphenol. Due to different catalytic properties and reaction conditions, p-/o-tert-butylphenol can be obtained, and 2, 4-di-tert-butylphenol and 2,6-di-tert-butylphenol. The world's production of p-tert-butylphenol is about tens of thousands of tons. It is mainly used in the production of oil-soluble phenolic resin, polycarbonate resin, rubber, coatings, inks, flame retardants, etc. It is also used in ultraviolet absorbers, surfactants, In terms of pesticides, its hydrogenation product butylcyclohexanol is used as a raw material for soaps and detergents and fragrances; o-tert-butylphenol can be used as a raw material for synthetic resins, pesticides, fragrances, etc.; 2,4-di-tert-butylphenol Antioxidant 168 can be produced by esterification with PC13, and can also be directly added to fuel oil as an antioxidant. Although my country's tert-butylphenol has a production history of several decades, the annual production capacity of p-tert-butylphenol is only about 300 t. In recent years, although there have been improvements in technology and catalysts, product quality has improved, and the technical level The production capacity is far behind that of foreign countries. For example, the annual output of the United States and Japan is more than 10,000 tons. The per capita consumption of tert-butylphenol in my country is small. In order to develop the tert-butylphenol industry in my country, it is necessary to carry out technological transformation on the one hand and realize the transformation from traditional intermittent production to more advanced continuous production. At the same time, we must develop multiple varieties of extended products. On the one hand, it is necessary to develop new and efficient catalysts.
【Application】[2] [3]
O-tert-butylphenol is mainly used as a raw material for antioxidants, plant protection agents, synthetic resins, medicines, pesticide intermediates and flavors and fragrances. Application examples are as follows:
1. Used to synthesize o-tert-butylcyclohexyl acetate, a spice. O-tert-butylcyclohexyl acetate has a floral and fruity aroma and is often used in soap flavors and cosmetic flavor formulations. Its synthesis method is divided into:
1) Synthesis of o-tert-butylcyclohexanol: Place a three-necked flask equipped with a thermometer, electric stirrer, dropping funnel and gas conduit on a water bath, add 70-80g of Ni‑Al‑Cr alloy powder and 150‑g of distilled water. 160ml, while stirring, slowly add 30% NaOH solution dropwise, control the reaction temperature to 50°C, and complete the dropwise addition in about 2 hours. Continue stirring the reaction at this temperature for 1 hour, and let it stand until all the catalyst to be generated settles and is poured out. Supernatant; wash with 30% NaOH solution and distilled water several times until pH≈8 to obtain active Raney Ni catalyst, which is stored immersed in alcohol or water; dissolve 95-105g of the above o-tert-butylphenol in 110ml of absolute ethanol , and 15-25g of active Raney Ni catalyst were placed in a 500ml autoclave, and the hydrogenation reaction was carried out for 3.5 hr at a temperature of 145-150°C and a pressure of 55-60 kg/cm2. After the reactants were cooled to nearly room temperature, take them out , filter, recover ethanol, and distill under reduced pressure to obtain 95-105g of o-tert-butylcyclohexanol;
2) Synthesis of o-tert-butylcyclohexyl acetate: Place 295-305 g of o-tert-butylcyclohexanol, 15-25g of fully dried anhydrous sodium acetate, and 205-215g of acetic anhydride in a flask, and heat them with an electric heating mantle Reflux at 145-150°C for 5 hr. After cooling, the reactant is washed successively with water, 2% NaOH solution, and saturated brine, and fractionated under vacuum to obtain 370-380g of o-tert-butylcyclohexyl acetate.
2. Synthesize styrenated hindered phenol or styrenated phenolic antioxidant products. The styrenated hindered phenol product specifically refers to a reaction mixture obtained by the catalytic alkylation reaction of styrene and o-tert-butylphenol. It has similar physical and chemical properties to other styrenated phenolic compounds and has a light yellow viscous appearance. Liquid, it is an alkylphenol non-polluting polymer antioxidant. It has the advantages of high efficiency, low toxicity, and low price. It can also be easily made into a water emulsion product, which is convenient for use in styrene-butadiene rubber, chloroprene rubber, nitrile rubber, etc. It is used as an antioxidant in synthetic rubber products obtained by emulsion polymerization, or as an antioxidant in lubricating oils. Preparation method, follow the following steps:
1) Add o-tert-butylphenol or phenolic compounds, organic acid catalysts, and polymerization inhibitors in proportion to the reaction kettle, introduce nitrogen for nitrogen protection, stir, raise temperature, add styrene dropwise, keep warm for reaction, reduce Pressure distill styrene to obtain styrenated hindered phenol products or styrenated phenolic products;
2) Cool down the styrenated hindered phenol product or styrenated phenolic product obtained in step (1), keep it warm, add a neutralizing decolorizing agent in proportion, stir, and mix thoroughly with the reaction solution to prepare styrene Hindered phenol antioxidant products or styrenated phenolic antioxidant products.
【Synthesis】[3]
In a three-necked flask equipped with a thermometer, electric stirrer, gas conduit and drying tube, add 110-120g of phenol and 2-3g of concentrated H2SO4 , anhydrous AlCl3 6-10g; raise the temperature to 50°C, and introduce isobutylene gas under strong stirring. When the weight of the reactant increases to about 60-70g, stop feeding isobutylene and raise the temperature again. Stir the reaction to 80°C for 2 hr, wash the reactant with 230ml×2 times of hot water, then evaporate the water under reduced pressure with a water jet pump, and then use vacuum distillation to steam out the crude product. The obtained crude product is recrystallized with 240ml petroleum ether. Freeze, filter and dry to obtain 125-135g of o-tert-butylphenol;
【Main Reference Materials���
[1] Zhang Aiping, Pan Lurang. Review of catalysts for the synthesis of tert-butylphenol[J]. Fine Petrochemicals, 1995, 3: 6-11.
[2] Du Fei; Guo Jingbo; Hua Beibei; Lu Wangjun; Guo Cheng; Ma Long. Preparation method of styrenated hindered phenol or styrenated phenolic antioxidant products. CN201110165747.9, application date 2011- 06-20
[3] Mei Jiaqing. A synthesis method of o-tert-butylcyclohexyl acetate for spices CN201210003100.0, application date 2012-01-06
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