Abstract: A new method of converting oligomeric chloroformates to high molecular weight polycarbonate is presented. By carefully controlling the relative concentrations and amounts of hydroxyl and chloroformate groups present in the oligomeric polycarbonate, the method of the invention provides for the efficient preparation of polycarbonate while minimizing phosgene usage. The product polycarbonates prepared by the method of the invention are fully capped with no additional phosgene required beyond that needed to prepare the oligomeric chloroformate starting material. The method of the present invention provides polycarbonates having non-detectable levels (<5 ppm) of aromatic hydroxyl endgroups, low polydispersity, and low levels of residual monomer and endcap, thereby obviating the need for monomer and endcap recycle.

Abstract: A solvent contaminant detection device is configured to detect the presence of dissolved contaminants in a solvent used for performing a solvent dry cleaning process. The solvent cleaning process utilizes a solvent based cleaning fluid comprising cyclic siloxane solvent. A detector output signal indicative of contaminant concentration may be processed to enable a user of a dry cleaning appliance to replace solvent regeneration absorption media when necessary and avoid the possibility of using solvent that is not purified, thereby reducing operational costs as well as improving wash quality of the appliance.

Abstract: A new method of converting oligomeric chloroformates to high molecular weight polycarbonate is presented. By carefully controlling the relative concentrations and amounts of hydroxyl and chloroformate groups present in the oligomeric polycarbonate, the method of the invention provides for the efficient preparation of polycarbonate while minimizing phosgene usage. The product polycarbonates prepared by the method of the invention are fully capped with no additional phosgene required beyond that needed to prepare the oligomeric chloroformate starting material. The method of the present invention provides polycarbonates having non-detectable levels (<5 ppm) of aromatic hydroxyl endgroups, low polydispersity, and low levels of residual monomer and endcap, thereby obviating the need for monomer and endcap recycle.

Abstract: A solvent vapor sensor for determining amounts of solvent vapor flowing during a solvent dry cleaning process is provided. The solvent cleaning process utilizes a solvent based cleaning fluid primarily made up of cyclic siloxane solvent. The solvent vapor sensor, i.e., a chemical specific sensor, may be configured in various forms, such as a spectroscopic sensor, a piezo-based sensor, a strain-gauge based sensor, and a capacitive sensor.

Abstract: The present invention provides an article cleaning apparatus comprising an air management mechanism, a cleaning basket assembly, a fluid regeneration device, a working fluid device, a clean fluid device, and a controller. The working fluid device is coupled to the fluid regeneration device, the cleaning basket assembly, and the air management mechanism. The clean fluid device is coupled to the cleaning basket assembly and the fluid regeneration device. The controller is coupled to the air management mechanism, the cleaning basket assembly, the working fluid device, the regeneration device, and the clean fluid device. The controller is configured to control a cleaning process. The present invention also provides a method for performing the cleaning process.

Abstract: Method and apparatus for recovering and purifying a solvent used in an article cleaning appliance are provided. The method allows passing solvent-based cleaning fluid from a wash basket through a coarse filter configured to remove relatively large particulates from the cleaning fluid. The method further allows passing cleaning fluid from the coarse filter through a particulate filter configured to remove relatively fine particulates from the cleaning fluid. An aqueous phase that may be present in the cleaning fluid is separated by decanting and coalescing through a separator/filter assembly. The cleaning fluid may then be passed through a regeneration cartridge for removing any water that may remain in the cleaning fluid, and for adsorbing organic contaminants that may be present in the cleaning fluid. Recovered solvent may be stored in a tank for subsequent use in a cleaning process performed by the appliance.

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: 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.

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: 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: 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.

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.