Hexafluorobisphenol A CAS 1478-61-1

In a pressure vessel, heating hexafluoroacetone and phenol for catalytic condensation reaction produces bisphenol AF, which is the traditional synthesis method of bisphenol AF. The HF used in the early stages of this method is both a solvent and a catalyst, with a reaction temperature of around 100 ℃ and a controlled pressure of 0.8-1.0 MPa. It requires special equipment such as pressure vessels and refrigeration devices, which have strict requirements for process technology and equipment, and cause serious acid pollution, making it unsuitable for large-scale industrial production. HF is highly toxic, corrosive, and dangerous, making it difficult to recycle and reuse.

Boron trifluoride, methylsulfonic acid, or trifluoromethanesulfonic acid can also be used as reaction solvents or catalysts. Boron trifluoride is a colorless gas with a suffocating and irritating odor, moderate toxicity, strong corrosiveness, and can corrode glass even when cold. It is thermally stable and undergoes explosive decomposition when in contact with water, producing boric acid and hydrogen fluoride.

Methyl sulfonic acid is a colorless and transparent liquid with strong acidity and high catalytic activity. It has attracted attention as a homogeneous catalyst, but has weak ability to oxidize organic compounds, low toxicity, and less corrosiveness than mineral acids. It is easy to separate from reaction mixtures and can be reused. Methanesulfonic acid has a low cost of use, can reduce the occurrence of side reactions, and can lower product color, making it an environmentally friendly catalyst. Trifluoromethane sulfonic acid does not free fluoride ions and has the function of a halogen-free liquid organic superacid. Hexafluoroacetone is a highly toxic gas that causes inconvenience in operation.

Hexafluoroacetone trihydrate has much lower toxicity, and stable trihydrate supplied to the market is usually selected. Concentrated acid can dehydrate the hydrate and convert it into hexafluoroacetone. The reaction equation is as follows:

In a pressure vessel, using HF as the solvent and catalyst, hexafluoroepichlorohydrin is isomerized into hexafluoroacetone, which reacts directly with phenol without purification to obtain bisphenol AF. The toxicity of the raw material hexafluoroepichlorohydrin in this method is relatively low, but it uses HF as a solvent and catalyst, requires reaction in an autoclave, and needs to be equipped with a refrigeration device. The operation is cumbersome and has certain risks, and good sealing measures need to be taken. This method is similar to the catalytic condensation of phenol and hexafluoroacetone, but has a higher industrial cost and is not conducive to large-scale production.

The Lewis acid catalyst for hexafluoropropane isomerization can be selected from A1C13, Cr2O3, A12O3, A1F3, etc. Cr2O3 or mixed catalysts mainly composed of Cr2O3 are particularly effective, with high activity, good selectivity, and long catalyst life. Using anhydrous HF to treat Cr O as a catalyst and running continuously for 1000 hours, hexafluoroepichlorohydrin can be almost quantitatively converted to hexafluoroacetone. The reaction equation is as follows:

In a 250 mL autoclave, Rammell, Peter Paul, and others shaken 100 g of hexafluoroepichlorohydrin and 100 g of HF at 100 ℃ for 24 hours to obtain hexafluoroacetone, with a conversion rate and selectivity of 98.9%. In the presence of phenol, bisphenol AF is obtained through reaction.

The 4-step synthesis method uses hexafluoroacetone trihydrate and aniline as raw materials, and synthesizes bisphenol AF through condensation, diazotization, hydrolysis, and Friedel Crafts alkylation in 4 steps at atmospheric pressure. A new method for the synthesis of bisphenol AF has been established by optimizing the synthesis conditions of intermediates.

This synthesis process is environmentally friendly, with mild reaction conditions, good selectivity, and high yield, avoiding the need for industrial high-pressure equipment and refrigeration devices. The reaction intermediates 4-amino-phenylhexafluoroisopropanol and 4-hydroxyhexafluoroisopropanol are widely used in many fields such as medicine and synthetic materials. This method has easy access to raw materials, low toxicity, and is easy to operate. Efforts have been made in raw material matching, catalyst research and development, and product separation and purification to reduce costs. Multiple products can be co produced, making it more competitive in the market. The reaction equation is as follows:

Low temperature fluorination of bisphenol A in an appropriate solvent yields bisphenol AF. The preparation process is simple, with low energy consumption, minimal pollution, high efficiency, and has good market prospects. This method provides a new approach for the preparation of bisphenol AF. The reaction equation is as follows:

The refining of reaction intermediates and bisphenol AF is a key technology in the production of bisphenol AF. Common refining measures include dissolution, filtration, distillation, extraction, decolorization, crystallization, and recrystallization. Dissolve in sodium hydroxide solution in the reaction product of phenol and hexafluoroacetone, filter, impurities containing iron hydroxide and tar.

Dilute the filtrate with water, then treat it with hydrochloric acid solution, and control the pH to 7-9 at 25 ℃ to obtain refined bisphenol AF with a purity of 99.8% and an absorbance difference AABS of 0.025 between 555-700 nm. Heat bisphenol AF and water, then cool the solution to obtain precipitated bisphenol AF; Or heat bisphenol AF and water to a temperature above 90 ℃, separate the liquid phase from the molten bisphenol AF phase, and cool the liquid phase to obtain precipitated bisphenol AF.