Abstract: A method of producing a purified ester-substituted phenol stream is provided. The method includes a first step of obtaining from a melt transesterification reaction a byproduct stream containing a residual ester-substituted diaryl carbonate, an ester-substituted phenol, a residual melt transesterification catalyst, and a catalyst degradation product. A second step includes treating the reaction byproduct stream to separate ester-substituted phenol and catalyst degradation product from residual ester-substituted diaryl carbonate and residual melt transesterification catalyst to create a light recycle stream containing ester-substituted phenol and catalyst degradation product and a heavy recycle stream containing residual ester-substituted diaryl carbonate and residual melt transesterification catalyst. A third step includes treating the light recycle stream to reduce catalyst degradation product concentration thereby producing a purified ester-substituted phenol stream.

Abstract: A non-reactive monomer mixture has a monomer component dispersed in a melted diaryl carbonate. The monomer component has one or more monomer compounds having a melting point below the melting point of the diaryl carbonate. Furthermore, the monomer component has less than 600 ppb alkali metal, an acid stabilizer, or both less than 600 ppb alkali metal and an acid stabilizer. The monomer compounds of the monomer component and the diaryl carbonate are present in a mole ratio of from 0.9 to 1.1. The monomer mixture is at a temperature between the melting temperature of the lowest melting monomer compound and the melting temperature of the diaryl carbonate.

Abstract: A non-reactive monomer mixture is formed from a dihydroxy component having one or more dihydroxy compounds dissolved in a melted diaryl carbonate. The dihydroxy component has less than 600 ppb alkali metal, an acid stabilizer, or both less than 600 ppb alkali metal and an acid stabilizer. The dihydroxy compounds of the dihydroxy component and the diaryl carbonate are present in a mole ratio of from 0.9 to 1.1. The monomer mixture is at a temperature between the saturation point of the monomer mixture and the highest melting temperature of the individual dihydroxy compounds. The non-reactive monomer mixture can be stored and transported and then polymerized to form polycarbonate upon addition of a catalyst.

Abstract: A method of producing a purified ester-substituted phenol stream is provided. The method includes a first step of obtaining from a melt transesterification reaction a byproduct stream containing a residual ester-substituted diaryl carbonate, an ester-substituted phenol, a residual melt transesterification catalyst, and a catalyst degradation product. A second step includes treating the reaction byproduct stream to separate ester-substituted phenol and catalyst degradation product from residual ester-substituted diaryl carbonate and residual melt transesterification catalyst to create a light recycle stream containing ester-substituted phenol and catalyst degradation product and a heavy recycle stream containing residual ester-substituted diaryl carbonate and residual melt transesterification catalyst. A third step includes treating the light recycle stream to reduce catalyst degradation product concentration thereby producing a purified ester-substituted phenol stream.

Abstract: A non-reactive monomer mixture has a monomer component dispersed in a melted diaryl carbonate. The monomer component has one or more monomer compounds having a melting point below the melting point of the diaryl carbonate. Furthermore, the monomer component has less than 600 ppb alkali metal, an acid stabilizer, or both less than 600 ppb alkali metal and an acid stabilizer. The monomer compounds of the monomer component and the diaryl carbonate are present in a mole ratio of from 0.9 to 1.1. The monomer mixture is at a temperature between the melting temperature of the lowest melting monomer compound and the melting temperature of the diaryl carbonate.

Abstract: A non-reactive monomer mixture is formed from a dihydroxy component having one or more dihydroxy compounds dissolved in a melted diaryl carbonate. The dihydroxy component has less than 600 ppb alkali metal, an acid stabilizer, or both less than 600 ppb alkali metal and an acid stabilizer. The dihydroxy compounds of the dihydroxy component and the diaryl carbonate are present in a mole ratio of from 0.9 to 1.1. The monomer mixture is at a temperature between the saturation point of the monomer mixture and the highest melting temperature of the individual dihydroxy compounds. The non-reactive monomer mixture can be stored and transported and then polymerized to form polycarbonate upon addition of a catalyst.

Abstract: A method of preparing polycarbonate includes a steps of providing a melt reaction mixture and allowing the melt reaction mixture to react to build molecular weight, thereby preparing the polycarbonate. The melt reaction mixture has a dihydroxy compound, an ester substituted diaryl carbonate mixture, and a melt transesterification catalyst where the ester substituted diaryl carbonate mixture may contain acid-substituted phenol. The method also includes the step of adjusting the molar ratio of acid-substituted phenol, if present, to melt transesterification catalyst (acid-substituted phenol/catalyst) in the melt reaction mixture to an amount of less than 10.

Abstract: Disclosed herein are processes for detecting the location of an interface between phases. In one embodiment, the process comprises: introducing a reaction mixture into a vessel wherein the reaction mixture is the product of an at least two phase interfacial reaction, and a difference in densities between at least two of the phases is less than or equal to about 1 g/cc, separating the reaction mixture into the phases with an interface located therebetween, measuring electrical inductance of the reaction mixture at different latitudinal locations; and determining the location of the interface.

Abstract: A method for the manufacture of bisphenols comprises introducing a combined feed stream comprising a feed stream and a recycle stream into a reactor system comprising at least one reactor containing a catalytic proportion of an acid catalyst and wherein the combined feed stream comprises a carbonyl compound and a stoichiometric excess of phenol; removing from the reactor system a reactor effluent; splitting the reactor effluent into a crystallization feed stream and an effluent recycle stream; extracting from said crystallization feed stream a bisphenol adduct, remainder comprising a mother liquor stream; dehydrating said mother liquor stream and said effluent recycle stream in a dehydrator wherein excess water and carbonyl compound are removed; and recycling the dehydrated mother liquor and the dehydrated effluent recycle stream back to the combined feed stream to effect improved production of p,p-bisphenol, along with increased reactor selectivity and reduced promoter quantities.

Abstract: A method for the manufacture of bisphenols comprises introducing a combined feed stream comprising a feed stream and a recycle stream into a reactor system comprising at least one reactor containing a catalytic proportion of an acid catalyst and wherein the combined feed stream comprises a carbonyl compound and a stoichiometric excess of phenol; removing from the reactor system a reactor effluent; splitting the reactor effluent into a crystallization feed stream and an effluent recycle stream; extracting from said crystallization feed stream a bisphenol adduct, remainder comprising a mother liquor stream; dehydrating said mother liquor stream and said effluent recycle stream in a dehydrator wherein excess water and carbonyl compound are removed; and recycling the dehydrated mother liquor and the dehydrated effluent recycle stream back to the combined feed stream to effect improved production of p,p-bisphenol, along with increased reactor selectivity and reduced promoter quantities.

Abstract: A method for the manufacture of bisphenols comprises introducing a combined feed stream comprising a feed stream and a recycle stream into a reactor system comprising at least one reactor containing a catalytic proportion of an acid catalyst and wherein the combined feed stream comprises a carbonyl compound and a stoichiometric excess of phenol; removing from the reactor system a reactor effluent; splitting the reactor effluent into a crystallization feed stream and an effluent recycle stream; extracting from said crystallization feed stream a bisphenol adduct, remainder comprising a mother liquor stream; dehydrating said mother liquor stream and said effluent recycle stream in a dehydrator wherein excess water and carbonyl compound are removed; and recycling the dehydrated mother liquor and the dehydrated effluent recycle stream back to the combined feed stream to effect improved production of p,p-bisphenol, along with increased reactor selectivity and reduced promoter quantities.

Abstract: Disclosed herein are processes for detecting the location of an interface between phases. In one embodiment, the process comprises: introducing a reaction mixture into a vessel wherein the reaction mixture is the product of an at least two phase interfacial reaction, and a difference in densities between at least two of the phases is less than or equal to about 1 g/cc, separating the reaction mixture into the phases with an interface located therebetween, measuring electrical inductance of the reaction mixture at different latitudinal locations; and determining the location of the interface.

Abstract: This invention relates to an economical and efficient process for purifying a reaction mixture obtained in a two-phase interfacial reaction for the preparation of polycarbonate. More particularly, the method of the invention provides for separating the reaction mixture into an organic phase, which includes the desired polycarbonate and undesirable impurities, and an aqueous phase. The organic phase is further purified by using a plate decanter in combination with coalescence and centrifugation.

Abstract: Brine produced in an interfacial polycarbonate plant can be treated to render it useful for recycle to the electrolytic cell, which is used in the production of chlorine. The waste brine stream is combined with ozone to produce an ozonated brine in which the amounts of organic contaminants such as phenol, bisphenol A and chloromethyltrimetlhyl ammonium chloride is reduced. The ozonated brine is then acidified to remove carbonates and produce a decarbonated brine which is then concentrated to produce a treated brine in which the concentration of NaCl is at least 10 wt % NaCl. A filtration step may be included prior to the ozonation to remove particulate impurities. When used in an interfacial polycarbonate plant in combination with chlorine, phosgene and polycarbonate producing facilities, this allows recycling of the brine waste stream and this provides an environmentally superior and highly cost effective method for the producing polycarbonate.

Abstract: A method for recovering substantially pure p,p-bisarylols from a mixture comprising the same by subjecting the mixture to vacuum distillation and melt crystallization in the absence of an adduct crystallization and the generation of a reaction recycle stream.