摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
Aromatic polyethers are prepared by displacement polymerization reaction in the presence of a water-immiscible solvent with boiling point at atmospheric pressure of greater than 110° C. and a density ratio to water of greater than 1.1:1 at 20-25° C. The polyethers are purified by processes comprising aqueous extraction, or filtration, or a combination thereof.
摘要:
Polyether polymers such as polyetherimides are prepared by a two-step reaction. The first step is the reaction between an alkali metal salt of a dihydroxy-substituted aromatic hydrocarbon, such as bisphenol A disodium salt, and a substituted aromatic compound such as 1,3-bis[N-(4-chlorophthalimido)]benzene, the alkali metal salt being employed in an amount less than stoichiometric. The intermediate low molecular weight polymer thus produced then undergoes reaction with additional alkali metal salt. By this method, a polyether polymer of closely controlled molecular weight can be conveniently prepared.
摘要:
The present invention provides a method of making polycarbonate oligomers, polycarbonate, molded articles formed from polycarbonate, and an apparatus for making polycarbonate. An oligomer mixture is first prepared by the steps of providing an equilibration system comprising a vessel, a reaction mixture contained within the vessel, and means for mixing the reaction mixture contained within the vessel wherein the reaction mixture comprises a melted activated diaryl carbonate composition, and a catalyst present in sufficient amount to initiate an oligomerization reaction between a dihydroxy composition and the activated diaryl carbonate to form polycarbonate oligomers. The method further includes the steps of introducing a melted dihydroxy composition to the reaction mixture contained within the equilibration system, maintaining the reaction mixture contained within the vessel at an oligomerization temperature, said oligomerization temperature being below the melting point the dihydroxy composition, and sufficiently high to allow formation of a homogeneous melt within the vessel, and continuously drawing off a product stream from the equilibration system, wherein the product stream comprises a polycarbonate oligomer mixture. This polycarbonate oligomer mixture is suitably used as a feed stock for producing polycarbonate in a polycondensation system. The polycarbonate is suitably used for the preparation of molded articles.
摘要:
The invention relates to a novel process for depolymerizing polyesters by subjecting the polyesters to catalysts and organic solvents which are substantially free of oxygen and water in order to produce macrocyclic polyester oligomers substantially free of hydroxybutyl terminated linear impurities.
摘要:
Embodiments of the invention provide for methods of producing a composition comprising a crosslinkable silane-terminated polymer having at least one crosslinkable silyl group in each molecule. The method comprises providing a polymer having at least one unsaturated group and at least one alcoholic hydroxyl group in each molecule, adding to the polymer a compound having a hydrogen-silicon bond and a crosslinkable silyl group in each molecule and a hydrosilylation catalyst to thereby carry out a hydrosilylation reaction to form a composition comprising hydrosilylated polyoxyalkylene polymers, reacting the hydrosilylated polyoxyalkylene polymers with at least one isocyanate in the presence of a first tin-free catalyst to form an isocyanate reacted hydrosilylated polymer, and optionally reacting the isocyanate reacted hydrosilylated polymer with a polyol having a nominal functionality of at least 2 to form a polyol reacted crosslinkable silane-terminated polymer.