Abstract: A method of purifying gluconate-containing brine is described which comprises first removing transition metal cations and other impurities by passage of the brine through a first ion exchange resin. The brine is then passed through a second ion exchange resin to effect removal of alkaline earth metal cations. In a third step the brine is treated with a carbonaceous adsorbent to remove impurities introduced by the ion exchange resins, as well as to effect removal of quaternary ammonium salts such as chloromethyl triethylammonium chloride. Methods for the regeneration of the carbonaceous adsorbent are described.

Abstract: In a continuous flow reactor one or more bisphenols is converted by the action of phosgene and aqueous base into a mixture of mono- and bisphenol chloroformates which are then treated with a catalyst, additional aqueous caustic and a monophenol to afford endcapped polycarbonates. At relatively high levels of added monophenol endcapped polycarbonate oligomers are obtained. The method is especially suited for the continuous preparation of endcapped oligomers of tetrabromobisphenol A polycarbonate. The method is characterized by efficient use of phosgene, and conversion of chloroformate groups to carbonate linkages aided by trialkylamine catalysts bearing at least one methyl group on nitrogen, such as N,N-dimethylbutylamine (DMBA).

Abstract: The specification describes a continuous process for the preparation of monofunctional aromatic chloroformates (MAC) having the structure (I) 1

Abstract: Thermally stable polymers comprising chain members derived from at least one 1,3-dihydroxybenzene moiety and at least one aromatic dicarboxylic acid moiety, said polymer being substantially free of anhydride linkages linking at least two mers of the polymer chain, are prepared using an interfacial method comprising the steps of: (a) combining at least one 1,3-dihydroxybenzene moiety and at least one catalyst in a mixture of water and at least one organic solvent substantially immiscible with water; (b) adding to the mixture from (a) a controlled stoichiometric ratio of at least one acid chloride and at least one base while maintaining the pH between about 4 and about 8.5, and (c) adjusting the pH of the reaction mixture to a value in the range of about 7 and about 9 following complete addition of acid chloride, and stirring the reaction mixture for a time sufficient to destroy any anhydride linkages in the polymer chain.

Abstract: This invention relates to a method for removing impurities from a brine solution, the brine solution comprising a water soluble chelating agent, the method comprising the steps of: a) adjusting the pH of the brine solution to a pH of from about 2 to about 4; b) passing the brine solution through a first functionalized resin; the first functionalized resin having functional groups capable of removing multivalent metal cations from the brine solution; c) adjusting the pH of the brine solution to a pH of from about 9 to about 11.5; and d) passing the brine solution through a second functionalized resin; the second functionalized resin having functional groups capable of removing alkaline earth metal cations from the brine solution.

Abstract: This invention relates to a process and apparatus for the continuous preparation of mono and bis-chloroformate products of halogenated dihydroxy compounds by an interfacial process. The mono and bis-chloroformate products may optionally be converted to capped oligomers.

Abstract: A continuous process for the preparation of monofunctional aromatic chloroformates (MAC) having the structure (I) wherein n is an integer from 1 to 5, and R1 represents hydrogen, a branched or unbranched alkyl group having from 1-15 carbon atoms, an aryl group which may be substituted or unsubstituted, a cycloaliphatic group which may be substituted or unsubstituted, or an arylalkyl group which may be substituted or unsubstituted, the method comprising the steps of a) introducing 1) an aqueous caustic solution; 2) a carbonyl chloride; 3) at least one monofunctional hydroxyaromatic compound; and 4) at least one inert organic solvent into a continuous reaction system; and b) effecting contact between 1), 2), 3) and 4) for a time and at conditions sufficient to produce a MAC of structure (I).

Abstract: In a continuous flow reactor one or more bisphenols is converted by the action of phosgene and aqueous base into a mixture of mono- and bisphenol chloroformates which are then treated with a catalyst, additional aqueous caustic and a monophenol to afford endcapped polycarbonates. At relatively high levels of added monophenol endcapped polycarbonate oligomers are obtained. The method is especially suited for the continuous preparation of endcapped oligomers of tetrabromobisphenol A polycarbonate. The method is characterized by efficient use of phosgene, and conversion of chloroformate groups to carbonate linkages aided by trialkylamine catalysts bearing at least one methyl group on nitrogen, such as N,N-dimethylbutylamine (DMBA).

Abstract: This invention relates to a method for removing impurities from a brine solution, the brine solution comprising a water soluble chelating agent, the method comprising the steps of:

Abstract: This invention relates to a process for the preparation of hydroxyaromatic chloroformate products suitable for use as chainstopping or endcapping agents. The process involves a semi-batch process in which an aqueous caustic solution is introduced into a vessel comprising a precharge solution, and careful control of the overall molar ratios of phosgene, caustic and hdyroxyaromatic compound are maintained.

Abstract: The present invention relates to a process to remove quaternary ammonium salt (QS), from brine solution. The process uses an adsorbent selected from the group consisting of activated carbon and pyrolyzed sulfonated polystyrene divinylbenzene resin, or mixtures thereof which aids in removing the quaternary ammonium salt (QS). The process can be generally carried out at a temperature ranging from about −10° C. to about 90° C., at a pH ranging from about 1 to about 13.

Abstract: Bischloroformate oligomer compositions are prepared by passing phosgene into a heterogeneous aqueous-organic mixture containing at least one dihydroxyaromatic compound, with simultaneous introduction of a base at a rate to maintain a specific pH range and to produce a specific volume ratio of aqueous to organic phase. By this method, it is possible to employ a minimum amount of phosgene. The reaction may be conducted batchwise or continuously. The bischloroformate composition may be employed for the preparation of cyclic polycarbonate oligomers or linear polycarbonate, and linear polycarbonate formation may be integrated with bischloroformate composition formation in a batch or continuous process.

Abstract: The method reduces the concentration of multivalent metal cations such as calcium, magnesium, iron, nickel, and chromium in brine solution containing a water-soluble metal chelating agent such as sodium gluconate. The method comprises subjecting the brine to primary brine treatment, and then readjusting the brine solution to a pH ranging from about 1.5 to about 5.5, and contacting the brine solution with at least one resin bed comprising a chelating ion exchange resin, typically at a temperature ranging from about 10.degree. C. to about 90.degree. C. and at a flow rate ranging from about 4 to about 32 resin bed volumes per hour; and recovering the brine solution.

Abstract: A method of preparing a polycarbonate comprising the steps of:a) charging at least one dihydroxy compound, an inert solvent, water, caustic, carbonyl halide, and catalyst to a vessel, and maintaining the pH of the reaction mixture between about 4 and about 12 during charging; andb) within an interval of between 0 and about 90% of the total carbonyl halide addition to the vessel, activating a reaction system that produces monofunctional aromatic chloroformates (MAC) and introducing the MAC to the vessel within the interval of 0 to about 90% of the total carbonyl halide addition to the vessel; where the MAC reaction system is coupled with the vessel, and where means are provided for delivery of the MAC from the reaction system to the vessel.

Abstract: Aromatic polycarbonates are prepared by a process which includes a continuous stage of oligomer preparation from a carbonyl halide such as phosgene and a dihydroxyaromatic compound such as bisphenol A, under interfacial conditions in the presence of an interfacial polycarbonate formation catalyst and an alkali metal hydroxide. The molar ratio of alkali metal hydroxide to carbonyl halide during oligomer preparation is up to 1.8:1, preferably in the range of about 1.45-1.8:1. The oligomeric intermediate product is then converted to high molecular weight polycarbonate having a low proportion of cyclic oligomers, which improves its thermodynamic stability.