Abstract: Bisphenol-A is purified in a process which comprises the following steps: a) cooling a liquid mixture comprising bisphenol-A and water in a bisphenol-A crystallizer to form bisphenol-A crystals in a liquid phase; b) separating the bisphenol-A crystals from the liquid phase; c) dividing at least a portion of the liquid phase into a bisphenol-rich organic phase and a water-rich phase; d) feeding phenol and at least a portion of the bisphenol-rich organic phase into a adduct crystallizer to form a crystalline adduct of phenol and bisphenol-A in a mother liquor, and e) separating the crystalline adduct from the mother liquor. Bisphenol-A of high purity at a high yield is obtained.

Abstract: A high purity 4,4′-isopropylidine-bis-(2,6-dibromophenol) characterised by ionic bromides less than 10 ppm, colour in alkaline solution from 60-100 HU, HPLC purity about 99.9%, APHA of 20% MeOH solution less than 10.0 HU, Fe less than 1.0 ppm, turbidity of 20% MeOH solution less than 5 NTU, pH of 10% slurry 6.0-7.0, size of the crystal particles, 250 to 280 microns with angle of repose lower than 30°.

Abstract: A method of crystallizing tetrabromobisphenol A is described, which comprises continuously and simultaneously feeding a methanolic tetrabromobisphenol A solution and water separately to a first crystallizer to obtain a slurry in which a part of the tetrabromobisphenol A is crystallized and continuously and simultaneously feeding said slurry and water separately to a second crystallizer to crystallize substantially the whole amount of the tetrabromophisphenol A.

Abstract: Tetrabromobisphenol-A is produced in a bromination process where no bromine or only a very small proportion of bromine is fed to the reactor. In the process aqueous hydrobromic acid, is the sole source or a major source of the bromine. In the process there are at least three concurrent continuous feeds to the reactor. One is composed of bisphenol-A and/or underbrominated bisphenol-A and a water-miscible organic solvent. The second is gaseous hydrogen bromide or preferably, aqueous hydrobromic acid, and the third is aqueous hydrogen peroxide. Optionally a small additional continuous feed of bromine can be employed. The feeds are proportioned to maintain a liquid phase containing (i) from above about 15 to about 85 wt % water, based upon the amount of water and water-miscible organic solvent in such liquid phase, and (ii) an amount of unreacted bromine that is in excess over the stoichiometric amount theoretically required to convert the bisphenol-A and/or underbrominated bisphenol-A to tetrabromobisphenol-A.

Abstract: This invention relates, inter alia, to a process for the production of tetrabromobisphenol-A by the bromination of bisphenol-A and/or underbrominated bisphenol-A, which process features: a water and water-miscible organic solvent reaction medium; a relatively high reaction temperature; and the presence, in the reaction medium, of both (i) excess unreacted Br2 during the feed of bisphenol-A to the reactor, and (ii) sufficient HBr to protect the tetrabromobisphenol-A produced against undesirable color formation. Tetrabromobisphenol-A precipitates from the reaction mass and is easily recovered. Product of high purity (97% or more) and very low color (APHA of 50 or less) can be produced, even when using large excesses of bromine in the reaction.

Abstract: Tetrabromobisphenol-A is produced in a bromination process where no bromine or only a very small proportion of bromine is fed to the reactor. In the process aqueous hydrobromic acid, is the sole source or a major source of the bromine. In the process there are at least three concurrent continuous feeds to the reactor. One is composed of bisphenol-A and/or underbrominated bisphenol-A and a water-miscible organic solvent. The second is gaseous hydrogen bromide or preferably, aqueous hydrobromic acid, and the third is aqueous hydrogen peroxide. Optionally a small additional continuous feed of bromine can be employed. The feeds are proportioned to maintain a liquid phase containing (i) from above about 15 to about 85 wt % water, based upon the amount of water and water-miscible organic solvent in such liquid phase, and (ii) an amount of unreacted bromine that is in excess over the stoichiometric amount theoretically required to convert the bisphenol-A and/or underbrominated bisphenol-A to tetrabromobisphenol-A.

Abstract: This invention relates, inter alia, to a process for the production of tetrabromobisphenol-A by the bromination of bisphenol-A and/or underbrominated bisphenol-A, which process features: a water and water-miscible organic solvent reaction medium; a relatively high reaction temperature; and the presence, in the reaction medium, of both (i) excess unreacted Br2 during the feed of bis-phenol-A to the reactor, and (ii) sufficient HBr to protect the tetrabromobisphenol-A produced against undesirable color formation. Tetrabromobisphenol-A precipitates from the reaction mass and is easily recovered. Product of high purity (97% or more) and very low color (APHA of 50 or less) can be produced, even when using large excesses of bromine in the reaction.

Abstract: This invention relates to a process for the production of tetrabromobisphenol-A by the bromination of bisphenol-A, which process features the addition of bisphenol-A to a reaction mass containing unreacted Br.sub.2 and 30 to 85 wt % water and an alcohol solvent, the reaction mass being at a relatively high temperature.

Abstract: This invention relates to a process for the production of tetrabromobisphenol-A by the bromination of bisphenol-A, which process features the addition of bisphenol-A to a reaction mass containing unreacted Br.sub.2 and 30 to 85 wt. % water and an alcohol solvent, the reaction mass being at a relatively high temperature.

Abstract: This invention relates to a process for the production of tetrabromobisphenol-A by the bromination of bisphenol-A, which process features: (a) feeding to a reaction mass (i) bisphenol-A and (ii) a stream of gaseous bromine, the gaseous stream having a Reynold's No. .gtoreq.40,000; (b) the reaction mass containing from about 50 to about 20,000 ppm unreacted bromine and less than 20 wt % HBr; and (c) the reaction mass having precipitated therefrom tetrabromobisphenol-A, all of (a)(ii), (b) and (c) occurring during the bisphenol-A feed.

Abstract: A process for producing n-propyl bromide during the bromination of bis- or trisphenols uses non-aqueous n-propanol as the bromination solvent, providing salable yields of n-propyl bromide to accompany the brominated bisphenol or trisphlenol.

Abstract: The present invention provides processes for recovering alkanols from fluids comprising the alkanol and aqueous hydrobromic acid without forming excessive amounts of alkyl bromide. In certain aspects of the invention, there are provided distillation systems wherein a fluid comprising an alkanol and aqueous hydrobromic acid is introduced into a distillation column at a point between the bottom and the top of the column to thereby separate the alkanol and the hydrobromic acid without causing the production of a significant amount of alkyl bromide.

Abstract: The present invention provides an industrially advantageous process for the preparation of an optically active 2-halo-1-(substituted phenyl)ethanol useful as medicines, agricultural chemicals or as intermediates thereof; and a simple process for the preparation of an optically active substituted styrene oxide or 2-amino-1-(substituted phenyl)ethanol useful as medicines, agricultural chemicals or intermediates thereof. A 2-halo-1-(substituted phenyl)ethanol represented by the following general formula (I) is allowed to contact, in the presence of a carboxylic anhydride, with an enzyme stereoselectively catalyzing ester interchange to produce an optically active 2-halo-1-(substituted phenyl)ethanol: ##STR1## (wherein X represents a chlorine atom or a bromine atom, and R.sup.1, R.sup.2 and R.sup.3 may be the same or different and each represent a hydrogen atom, a halogen atom, a C.sub.1-5 alkyl group, a C.sub.1-5 haloalkyl group, a C.sub.

Abstract: This invention relates to a process for the production of tetrabromobisphenol-A by the bromination of bisphenol-A, which process features: a water and water miscible solvent reaction medium; a relatively high reaction temperature; the presence, in the reaction medium, of unreacted Br.sub.2 during the feed of bisphenol-A to the reactor; and the oxidation of co-produced HBr to yield Br.sub.2.

Abstract: This invention relates to a method of producing a high-melting powder of 2,2-bis?4'-(2",3"-dibromopropoxy)-3',5'-dibromophenyl!propane characterized by comprising a step of adding water to a solution of 2,2-bis?4'-(2",3"-dibromopropoxy)-3',5'-dibromophenyl!-propane in an organic solvent in the presence of a surfactant to give a water-in-oil emulsion and a step of removing the organic solvent from the emulsion in the presence of a crystal nucleus to induce crystallization to give an aqueous dispersion of 2,2-bis?4'-(2",3"-dibromopropoxy)-3',5'-dibromophenyl!propane. In accordance with this invention, crystallization is carried out in the state of an emulsion under assistance of a surfactant so that an ordinary stirrer can be used in production without resort to any special high-shear stirring equipment. Moreover, since a high-melting grade of 2,2-bis?4'-(2",3"-dibromopropoxy)-3',5'-dibromophenyl!propane is obtained as an aqueous dispersion, workability and safety in the subsequent processing are improved.

Abstract: This invention provides an environmentally acceptable method for recovery of phenolic and brominated phenolic compounds, alcohol solvent, and bromide values from the a reaction medium liquid mixture formed in the production of a tetrabromobisphenol-A predominant product. The process comprises (a) separating the tetrabromobisphenol-A predominant product and alkyl bromide from the reaction medium thereby forming a liquid mixture containing alcohol, phenolic and brominated phenolic compounds, HBr, and water; (b) treating the liquid mixture with a sufficient amount of alkaline or alkaline earth metal hydroxide so as to form a treated aqueous mixture having a pH in the range of from about 9.5 to about 14.0, and containing MBr.sub.

Abstract: The quality of a product predominant in tetrabromobisphenol-A is enhanced by contacting the product with a quality enhancing amount of treated water and heat treating the product for a period of time and at a temperature which are sufficient to obtain a TBBPA predominant product having less than about 20 ppm of ionic impurities.

Abstract: A process for hydrodehalogenating halogenated aromatics present in a contaminated aqueous environmental source in which the halogenated aromatics are reacted with hydrogen gas or a source of hydrogen gas in the presence of a basic proton acceptor and a catalyst of palladium on carbon.

Abstract: A method for recovering hydrobromic acid and methanol from a filtrate obtained by brominating bisphenol A in a methanol solvent and filtering off the resulting brominated bisphenol A, which comprises adding water to the filtrate, followed by distillation for purification.

Abstract: Polychlorinated biphenyls present as contaminants in fluids such as petroleum distillates are effectively removed by reacting with sodium or potassium hydroxide in the presence of or through subsequent filtration through an adsorbent such as alumina and/or diatomaceous earth. A mixture of diatomaceous earth, calcium hydroxide and potassium hydroxide in the ratio of 10/1/1 is exposed to the fluid to be decontaminated by stirring a quantity of the mixture in a quantity of the fluid or by passing the fluid through a column packed with the mixture. Alternatively, the contaminated fluid is mixed with the alkali metal hydroxide and then passed through a column of adsorbent such as activated basic alumina. The fluid may be pretreated by storing in a tank over a bed of potassium hydroxide flakes. Ferric oxide may be added to the reaction mixture to enhance the retention of the octachlorodihydroxybiphenyl on the adsorbent material.

Abstract: A process for forming a substantially insoluble solid polymer from halogeneated phenolic compounds dissolved in a liquid medium using an oxidizing agent. NaOCl and NaOBr are used as oxidizing agents to initiate the polymerization reaction among the halogenated phenolic compounds. The polymer precipitates from the system to form a claylike solid. The solid is environmentally safe and may be disposed of in a sanitary landfill.

Abstract: Highly pure dihalodiphenols or predetermined, statistical mixtures of unreacted, monohalo- and dihalodiphenols are obtained reacting the diphenol, which is suspended or dissolved in a suitable solvent, with a halogen while concurrently purging the reaction with a gas that is inert to the reaction.

Abstract: A continuous process for obtaining highly pure, high molecular weight aromatic polycarbonates from highly pure, halogenated diphenols.

Abstract: A method of removing an impurity of the group chlorinated dibenzo-p-dioxins, chlorinated dibenzofurans, chlorinated hydroxydiphenylethers and chlorinated diphenylethers from a substance containing the same which comprises contacting said substance with an agent which is hydrazine, acetylene, an acetylene derivative or a compound which under the processing conditions is a source of hydrazine or acetylene.

Abstract: A process for purifying crude diphenols via a water co-solvent system is disclosed.

Abstract: 1,1,1-trichloro-2,2-bis(4-hydroxyphenyl)ethane can be dehydrohalogenated to 1,1-dichloro-2,2-bis(4-hydroxyphenyl) ethylene by treating the former with a dehydrochlorinating agent comprising liquid methyl amine and an effective amount of an additive to accelerate the dehydrochlorinating effect of the liquid methyl amine selected from the class consisting of a certain class of inorganic and organic salts.

Abstract: A process for the preparation of bisphenols is described which comprises reacting, in a reaction zone, at least 2 moles of a phenol with a carbonyl compound, at a temperature of from 40.degree. to 95.degree. C., in the presence of an acid ion exchanger, optionally partially modified with a compound having an acidic reacting group and a mercaptan group, and recovering the bisphenols from the reaction zone effluent, characterized in that the reaction zone effluent is contacted with an acid ion exchanger in metal salt form and/or a weak base ion exchanger. As a result, it has been found that the formation of undesirable compounds is substantially reduced.

Abstract: 4,4'-isopropylidene-bis(2,6-dibromophenol) is produced by reacting 4,4'-isopropylidene diphenol with hydrogen bromide or a mixture of hydrogen bromide with up to an equimolar amount of free bromine in admixture with hydrogen peroxide and in the presence of water and an inert organic liquid.

Abstract: Impure 1,1-dichloro-2,2-bis(4-hydroxyphenyl)ethylene can be purified by heating the latter either with phenol alone or with a mixture of methylene chloride and phenol, allowing the heated mixture to cool until crystallization occurs and removing the above-identified purified dichloroethylene compound.

Abstract: A method is provided for making substantially pure 1,1-dichloro-2,2-bis(4-hydroxyphenyl)ethylene by dehydrochlorinating 1,1,1-trichloro-2,2-bis(4-hydroxyphenyl)ethane with a methanol solution of potassium hydroxide, followed by purifying the crude reaction product with a mixture of a hot aromatic solvent and a polar solvent, such as methanol.

Abstract: 1,1,1-Trichloro-2,2-bis(4-hydroxyphenyl)ethane can be dehydrohalogenated to 1,1-dichloro-2,2-bis(4-hydroxyphenyl)ethylene by treating the former with liquid ammonia.