General Electric Company

Other

Sabic Innovative Plastics IP B.v.

Timothy Brydon Burnell

Patrick Joseph McCloskey

Paul Michael Smigelski, Jr

Jeffrey H Wengrovius

James Anthony Cella

Ganesh Kailasam

Daniel Joseph Brunelle

Judith Stein

Jonathan D Rich

Elliott West Shanklin

Peter M Miranda

Michael A Zumbrum

Radislav Alexandrovich Potyrailo

Larry Neil Lewis

James Alfred Day

Clifford L Spiro

David C Gross

Alberto Nisoli

Virginia M Van Valkenburgh

Terry E Krafft

Paul Michael Smigelski

Hendricus Franciscus Zirkzee

Linda L McCracken

Rudy Francois Alain J Peemans

Juan Rodriques Ordonez

Eva Mardomingo-Sant&aacute;s

Johan Pieter Anna Heuts

Gerardo Hidalgo-Llinas

Ignacia Vic Fernandez

Edward Venama

Merry S Huber

High yields of ester-substituted diary carbonates such as bis-methyl salicyl carbonate were obtained by the condensation of methyl salicylate with phosgene in the presence of a phase transfer catalyst (PTC) in an interfacial reaction system in which the pH of the aqueous phase was greater than 9.3. Using the method of the present invention conversions of greater than 99% were obtained whereas under standard conditions using triethylamine as the catalyst conversions were limited to 70-75% of the methyl salicylate starting material even with a 20 mole % excess of added phosgene. The optimized conditions of the of the present invention use only a slight excess of phosgene and represent an attractive route for the manufacture of bis methyl salicyl carbonate and ester-substituted diaryl carbonates generally.

Interfacial method of preparing ester-substituted diaryl carbonates

High yields of ester-substituted diary carbonates such as bis-methyl salicyl carbonate were obtained by the condensation of ester-substituted phenols with phosgene in the presence of a phase transfer catalyst (PTC) and optionally a tertiary amine catalyst in a solvent free reaction system comprising an aqueous phase held at a pH of 8.3 or higher. The optimized conditions of the present invention use an excess of ester-substituted phenol relative to phosgene and high conversion of phosgene to ester-substituted diaryl carbonate is observed. The product ester-substituted diaryl carbonate may be conveniently isolated as a solid by filtration or as a liquid in which the excess ester-substituted phenols serves as solvent. The method represents an attractive route for the manufacture of bis methyl salicyl carbonate and ester-substituted diaryl carbonates generally. The ester-substituted diaryl carbonates are useful for the preparation and modification of polycarbonates.

Solventless preparation of ester-substituted diaryl carbonates

In an embodiment, the present invention is directed a method and an apparatus comprising irradiating a polymer sample with at least one wavelength of substantially monochromatic light and monitoring radiation emitted by the polymer sample which is correlated to sample hydrolysis and a change in polymer molecular weight.

Method and apparatus for nondestructive determination of polymer hydrolytic stability

The present invention relates to a method of neutralizing residual acid species in crude dihydric phenol comprising the step of introducing a thermally stable organic base selected from the group consisting of tetraalkyl phosphonium hydroxides, tetraorganophosphonium carboxylic acid salts, or a mixture thereof into the crude dihydric phenol.

Process for the neutralization of residual acid species in crude dihydric phenols

Polycarbonates containing low or undetectable levels of Fries rearrangement product may be prepared by the melt reaction of a dihydroxy aromatic compound such as bisphenol A with an ester-substituted diaryl carbonate such as the diaryl carbonate of methyl salicylate, bis-methyl salicyl carbonate. Low levels of Fries product are obtained as the combined result of a highly effective catalyst system which suppresses the Fries reaction and the use of lower melt polymerization temperatures relative to temperatures required for the analogous polymerization reaction using diphenyl carbonate.

Method of polycarbonate preparation

Solid state polymerization of partially crystalline polycarbonate oligomers bearing ester-substituted terminal groups occurs at useful reaction rates despite their high level of endcapping. Partially crystalline polycarbonate oligomers having ester substituted terminal groups may be obtained in a single step by reaction of an ester substituted diaryl carbonate such as bis-methyl salicyl carbonate with a dihydroxy aromatic compound such as bisphenol A in the presence of a transesterification catalyst such as sodium hydroxide. Alternatively, amorphous oligomeric polycarbonates incorporating ester substituted endgroups may be obtained through careful control of the melt reaction conditions. The amorphous oligomeric polycarbonates are crystallized upon exposure to solvent vapor and subsequently undergo solid state polymerization at synthetically useful reaction rates.

Method of polycarbonate preparation by solid state polymerization

High yields of ester-substituted diary carbonates such as bis-methyl salicyl carbonate were obtained by the condensation of ester-substituted phenols with phosgene in the presence of a phase transfer catalyst (PTC) and optionally a tertiary amine catalyst in a solvent free reaction system comprising an aqueous phase held at a pH of 8.3 or higher. The optimized conditions of the present invention use an excess of ester-substituted phenol relative to phosgene and high conversion of phosgene to ester-substituted diaryl carbonate is observed. The product ester-substituted diaryl carbonate may be conveniently isolated as a solid by filtration or as a liquid in which the excess ester-substituted phenols serves as solvent. The method represents an attractive route for the manufacture of bis methyl salicyl carbonate and ester-substituted diaryl carbonates generally.

The stoichiometric ratio of dihydric phenol to diarylcarbonate during production of polycarbonates can be evaluated by infrared analysis, preferably using an FTIR spectrometer, to detect the amount of BPA or other dihydric phenol in the mix tank. In one format of the method, one or both of two characteristic peaks, reflecting the methyl CH bonds and hydroxyl OH bonds are evaluated. These peaks occur equally in BPA monomers and oligomers, and hence are independent of the degree of oligomerization or polymerization which has occurred. For this reason, monitoring of stoichiometry can be performed on the contents of the mix tank, or on the products from or contents of any downstream reactors. Using a calibration curve, the absorbance associated with these bonds is converted into a measure of the concentration of BPA and from that to first moles and then grams of BPA in the mixture being tested. The amount of DPC is determined by subtracting the number of grams of BPA from the total initial sample weight. In another format, a ratio of the size of the peaks associated with DPC carbonyl and BPA methyl is used directly to determine the ratio of DPC to BPA.

Infrared evaluation of the stoichiometric ratio of dihydric phenol to diarylcarbonate during production of polycarbonates

Acidic impurities in dihydroxyaromatic compounds such as bisphenol A, as illustrated by sulfonic acids and mercaptocarboxylic acids, can have an adverse effect on the molecular weight of a polycarbonate prepared therefrom by transesterification. The same is true of acidic impurities in diaryl carbonates such as diphenyl carbonate, as illustrated by salicylic acid and ferric chloride. The reagents are analyzed for these impurities. Based on the analysis, the reagents are discarded or recycled, or a compensatory amount of alkali metal hydroxide is employed as a catalyst in the reaction.

Optimization of polycarbonate preparation by transesterification

This invention relates to a method for the preparation of polycarbonate by the melt process comprising reacting a diphenol and a diarylcarbonate in the presence of a catalyst system comprising a catalytically effective amount of an alkali and/or alkali earth metal salt of a non volatile acid and a base.

Salts of non-volatile acids as polymerization catalysts

This invention relates to mixed dialkali metal salts of sulfuric acid containing at least one cesium equivalent useful in catalyst systems in melt polymerizations. The catalysts provide product with low branching side reaction products and good properties.

Mixed dialkali metal salts of sulfuric acid containing at least one cesium equivalent as polymerization catalysts

The present invention relates to a method for the preparation of polycarbonate comprising preparing a polycarbonate by a melt process by reacting a diphenol and a diaryl carbonate in the presence of a catalytically effective amount of one or more alkali and or alkali earth metal salts of chelating agents. Suitable chelating agents include nitrilotriacetate and EDTA.

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Schenectady, NY, United States of America

Timothy Brydon Burnell