# US 4,396,757 A · Process for preparing polyphenols > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,396,757 A - Document ID: US4396757A - Status: Granted - Kind: A - Application number: 06/208,833 - Filed: 1980-11-17 - Granted: 1983-08-02 - Earliest claimed: 1980-11-17 - Inventors: Adalat V. O. Ragimov; Yavus I. O. Rustamov; Ibragim I. O. Ragimov; Anush G. K. Mamedova; Tadzhaddin S. O. Zakirov; Amrulla F. O. Amrullaev - Web page: https://patentgrep.com/patent/US4396757A ## CPC - C08G 65/44: by oxidation of phenols - C08G 61/02: Macromolecular compounds containing only carbon atoms in the main chain of the macromolecule, e.g. polyxylylenes - C08G 65/38: derived from phenols - C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS ## Abstract A process for preparing polyphenols, including oxidative polycondensation of a phenol in an aqueous medium in the presence of an oxidizer as well as a subsequent separation of the end product. The starting phenol is mixed with an aqueous solution of an alkali of 5 to 56% concentration in a molar ratio between 1:2.4 and 1:0.25 and heated to a temperature between 70.degree. and 170.degree. C., while air, which furnishes oxygen as the oxidizer, is passed through the reaction mixture. An apparatus for carrying out the process of the invention comprises a kettle equipped with a heater, a shaft with blades mounted within said kettle and connected to a drive for revolving the shaft, a perforated pipe assembled at the bottom portion of the kettle and communicating with an air blower. The perforated pipe communicates with the air blower through an air treatment chamber. ## Claims ### Claim 1 Method for the polycondensation of phenolic monomers, which comprises heating a mixture of a polymerizable phenolic monomer in an aqueous solution of an alkali of a concentration of 5-56% and having a molar ratio of phenolic monomer to alkali of 1:2.4-1:0.25 to a temperature of 70.degree.-170.degree. C., said phenolic monomer being phenol, alkyl (C.sub.8 H.sub.17) phenol, cresol, alpha-naphthol, beta-naphthol or hydroquinone, and passing air through the thus heated mixture to effect polycondensation of phenolic monomer to form the corresponding polymer of said phenolic monomer. ### Claim 2 (depends on 1) Method according to claim 1 wherein said alkali is potassium hydroxide in a concentration of 11-56%. ### Claim 3 (depends on 1) Method according to claim 1 wherein said alkali is sodium hydroxide in a concentration of 25-56%. ### Claim 4 (depends on 1) Method according to claim 1 wherein the air prior to being passed through said heated mixture is treated to remove carbon dioxide therefrom. ### Claim 5 (depends on 4) Method according to claim 4 wherein said treatment is effected by treating the air with a concentrated alkali solution. ### Claim 6 (depends on 1) Method according to claim 1 wherein said air is passed through the heated mixture at a flow rate of from 0.007 to 0.016 m.sup.3 /hr per kilogram of said monomer. ### Claim 7 (depends on 1) Method according to claim 1 wherein after completion of the reaction effected by passing air through said heated mixture, the resulting reaction mixture is cooled to temperature of 20.degree.-80.degree. C. ### Claim 8 (depends on 7) Method according to claim 7 wherein the cooled reaction mixture is neutralized with a mineral acid and washed with water. ### Claim 9 (depends on 1) Method according to claim 1 wherein after completion of the polycondensation reaction, carbon dioxide is passed through the resulting reaction mixture. ### Claim 10 (depends on 8) Method according to claim 8 wherein the neutralized, washed reaction mixture is dried at a temperature of 80.degree.-135.degree. C. ### Claim 11 (depends on 1) Method according to claim 1 wherein the air after being passed through the reaction mixture is passed through an aqueous alkaline solution. ### Claim 12 (depends on 10) Method according to claim 10 wherein the air is cooled and then passed through an aqueous solution. ### Claim 13 (depends on 1) Method according to claim 1 wherein the phenolic monomer is phenol, alkyl (C.sub.8 H.sub.17) phenol or cresol and the reaction is effected at a temperature of 130.degree.-155.degree. C. ### Claim 14 (depends on 1) Method according to claim 1 wherein upon completion of the polycondensation reaction, the reaction mixture is cooled to a temperature of 50.degree.-80.degree. C., mixed with water and carbon dioxide is blown therethrough.