Patent GB-808490-A (GB)
Title: Process for the manufacture of carbonic acid esters
IPC: C08G64/24
Filed: 1957-03-22
Abstract: Polycarbonates are made by reacting dihydroxy compounds with phosgene or bis-chlorocarbonic acid esters of dihydroxy compounds in an aqueous alkaline medium or suspension, if desired in the presence of an inert organic solvent, characterized by adding small amounts of tertiary amines or salts thereof to the reaction mixture before or during the reaction.  Suitable tertiary amines are trimethylamine, triethylamine, N,N - dimethylcyclohexylamine, N,N-diethylcyclohexylamine, N,N-dimethylaniline, N,N-diethyl aniline, pyridine, picoline, methylpyridine, quinoline or salts thereof. Amounts of 0.05 to 1 per cent by weight of such an amine based on the hydroxy compound are sufficient.  The reaction proceeds very rapidly with a small excess of phosgene at or below room temperature. Suitable dihydroxy compounds for use as starting materials are di-monohydroxyarylalkanes, or dimonohydroxyarylsulphones, if desired in admixture with other dihydroxy compounds, or mixtures of these and other aromatic dihydroxy compounds and aliphatic and/or cycloaliphatic dihydroxy compounds.  Surface-active substances such as ionic wetting agents, e.g. fatty acids and their salts, acid sulphuric acid esters of fatty alcohols or their salts, aliphatic or aromatic sulphonic acids or their salts, acid amides from aliphatic carboxylic acids with alkylaminosulphonic acids or their salts, quaternary ammonium compounds, and non-ionic surface-active substances such as polyglycol ethers or their esters with fatty acids and alkyl-aryl-polyglycol ethers, may be added to the reaction mixture, e.g. in amounts of 0.5-5 per cent by weight based on the dihydroxy compounds, before or during the reaction.  In examples: (2) into a mixture of 2,2-(4,41-dihydroxy-diphenyl)-propane, sodium hydroxide, and methylene chloride, gaseous phosgene is introduced with stirring at 25 DEG  C. within 2 hours with subsequent addition of triethylamine, tributylamine or N,N-dimethylcyclohexylamine and with the optional addition of sodium alkyl sulphonate, sodium diisobutylnaphthalene sulphonate, a polyglycol ether of oleyl alcohol with 15 mol. of ethylene oxide, the sodium salt of the sulphonic ester of the polyglycol ether obtained from 1 mol. of alkyl-phenol and 3 mol. of ethylene oxide, the sodium salt of oleic acid methyltauride, the polyglycol ether of benzylated p-hydroxydiphenyl or an ester from abietic acid and polyglycol ether, as surface-active compounds, to produce polycarbonates; (3) into a mixture of 2,2-(4,41-dihydroxy - diphenyl) - propane, 4,41 - dihydroxydiphenylsulphone, methylene chloride, water and sodium hydroxide, phosgene is introduced with stirring at 25 DEG  C. within 2 hours and triethylamine and the sodium salt of diiso-butylnaphthalene-sulphonic acid are then added thereto to form a methylene chloride solution of a polycarbonate; (4) into a mixture of 2,2-(4,41 - dihydroxydiphenyl) - propane, 4,41 - dihydroxydiphenyl, methylene chloride, water and sodium hydroxide, phosgene is introduced at 25 DEG  C. over 2 hours, and triethylamine and the sodium salt of diiso-butylnaphthalene-sulphonic acid are then added thereto, forming a methylene chloride solution of a polycarbonate.  Specifications 772,627, 808,485, 808,486 and 808,487 are referred to.ALSO:Carbonic acid esters are produced by reacting hydroxy compounds with phosgene or chlorocarbonic acid esters of hydroxy compounds in an aqueous alkaline medium or suspension, if desired in the presence of an inert organic solvent, characterized by adding small amounts of tertiary amines or salts thereof to the reaction mixture before or during the reaction.  Suitable tertiary amines are trimethylamine, triethylamine, N,N-dimethylcyclohexylamine, N,N-diethylcyclohexylamine, N,N - dimethylaniline, N,N - diethylaniline, pyridine, picoline, methylpyridine, quinoline or salts thereof.  Amounts of 0.05 to 1 per cent by weight of such an amine based on the hydroxy compound are sufficient.  The reaction proceeds very rapidly with a small excess of phosgene at or below room temperature.  Suitable starting materials are ethyl alcohol, butyl alcohol, allyl alcohol, methallyl alcohol, phenols, cresols, p-tert. butylphenol, naphthols, hydroquinone, resorcinol, dihydroxynaphthalenes, 4,41 - dihydroxydiphenylalkanes, phloroglucinol, glycol, glycerol and pentaerythritol or mixtures thereof which may be converted with phosgene or a chlorocarbonic acid ester according to the above method to give carbonates such as diethyl-, dibutyl-, diallyl-, diphenyl-, di-p-tert.-butylphenyl, di-a -naphthyl, di - p - hydroxydiphenyl, 4,41 - dihydroxydiphenyl - 2,2 - propane - diphenyl-, phloroglucinoltriphenyl -, 4,41 - dihydroxy - diphenyl methane-bis-allyl- or glycerol-triallylcarbonate.  Dihydroxy compounds may also be used as starting materials to produce polycarbonates (see Group IV (a)), and in such reactions surface-active substances may be added to the reaction mixture to increase the reaction speed.  In Example (1) phosgene is passed into a mixture of p-tert.-butylphenol, sodium hydroxide and water with the addition of triethylamine.  A comparative example is described in which the tertiary amine is omitted showing that a much longer reaction time is then required.  (For examples of the production of polycarbonates see Group IV (a)).  Specifications 772,627, 808,485, 808,486 and 808,487, [all in Group IV (a)], are referred to.