Abstract: The invention relates to a process for working up water containing 4,4?-dichlorodiphenyl sulfoxide and/or 4,4?-dichlorodiphenyl sulfone as impurities, comprising: (a) mixing the water containing 4,4?-dichlorodiphenyl sulfoxide and/or 4,4?-dichlorodiphenyl sulfone as impurities with an organic solvent in which 4,4?-dichlorodiphenyl sulfoxide and/or 4,4?-dichlorodiphenyl sulfone have a solubility of at least 0.5 wt % based on the amount of 4,4?-dichlorodiphenyl sulfoxide and/or 4, 4?-dichlorodiphenyl sulfone and organic solvent at 20° C., which forms a two-phase system with water and which can be stripped from water with a stripping gas and subsequently separating the obtained mixture into an aqueous phase and an organic phase, and (b) stripping the organic solvent from the aqueous phase with a stripping gas.

Abstract: The invention relates to crystals (C) consisting of at least 98% by weight of 4,4?-dichlorodiphenylsulfone, 0 to 2% by weight of impurities and 0 to 2% by weight of at least one solvent (c). Moreover, the present invention relates to a crystal composition (CC) comprising crystals (C) and a process for the production of the crystal composition (CC) and the crystals (C).

Abstract: The invention relates to a process for purifying crude 4,4?-dichlorodiphenyl sulfone comprising: (a) dissolving the crude 4,4?-dichlorodiphenyl sulfone which may contain water in an organic solvent in which 4,4?-dichlorodiphenyl sulfone has a solubility of 0.5 to 20% at 20° C. and optionally adding water to obtain a solution which comprises 4,4?-dichlorodiphenyl sulfone, the organic solvent and 1 to 30 wt % water based on the amount of 4,4?-dichlorodiphenyl sulfone and water; (b) cooling the solution to a temperature below the saturation point of 4,4?-dichlorodiphenyl sulfone to obtain a suspension comprising crystallized 4,4?-dichlorodiphenyl sulfone; (c) carrying out a solid-liquid separation to obtain residual moisture containing 4,4?-dichlorodiphenyl sulfone and a mother liquor; (d) washing the residual moisture containing 4,4?-dichlorodiphenyl sulfone with an organic solvent in which 4,4?-dichlorodiphenyl sulfone has a solubility of 0.5 to 20% at 20° C.

Abstract: The invention relates to a process for purifying 4,4?-dichlorodiphenyl sulfone comprising: (a) providing a suspension comprising particulate 4,4?-dichlorodiphenyl sulfone in carboxylic acid, (b) carrying out a solid-liquid separation of the suspension to obtain residual moisture containing 4,4?-dichlorodiphenyl sulfone and a carboxylic acid comprising filtrate, (c) washing the residual moisture containing 4,4?-dichlorodiphenyl sulfone with an aqueous base and then with water, (d) mixing the aqueous base after being used for washing with a strong acid, or mixing the aqueous base after being used for washing, the carboxylic acid comprising filtrate and a strong acid, (e) carrying out a phase separation in which an aqueous phase and an organic phase comprising the carboxylic acid are obtained.

Abstract: The invention relates to a process for producing 4,4?-dichlorodiphenyl sulfone comprising reacting a solution comprising 4,4?-dichlorodiphenyl sulfoxide and at least one linear C6-C10 carboxylic acid as solvent with an oxidizing agent to obtain a crude reaction product comprising 4,4?-dichlorodiphenyl sulfone, wherein the concentration of water in the reaction mixture is kept below 5 wt %, the process comprising: (a) adding 0.9 to 1.05 mol oxidizing agent per mol 4,4?-dichlorodiphenyl sulfoxide uniformly distributed to the solution at a temperature in the range from 80 to 105° C. over a period from 1.5 to 5 h in a first step to obtain the reaction mixture; (b) agitating the reaction mixture after completion of the first step at the temperature of the first step for 5 to 30 min without adding oxidizing agent; (c) adding 0.05 to 0.2 mol oxidizing agent per mol 4,4?-dichlorodiphenyl sulfoxide to the reaction mixture at a temperature in the range from 80 to 105° C.

Abstract: The invention relates to a process for producing 4,4?-dichlorodiphenyl sulfone, comprising: (a) reacting 4,4?-dichlorodiphenyl sulfoxide and an oxidizing agent in at least one carboxylic acid as solvent to obtain a reaction mixture comprising 4,4?-dichlorodiphenyl sulfone and carboxylic acid; (b) separating the reaction mixture into a first stream comprising 4,4?-dichlorodiphenyl sulfone and a second stream comprising carboxylic acid; (c) purifying the second stream comprising carboxylic acid by distilling a part of the second stream comprising carboxylic acid stripping low boilers from at least a part of the second stream comprising carboxylic acid (d) recycling the purified carboxylic acid into the reaction (a).

Abstract: The invention relates to a process for producing 4,4?-dichlorodiphenyl sulfone, comprising: (I) reacting thionyl chloride, chlorobenzene and aluminum chloride forming an intermediate reaction product and hydrogen chloride; (II) mixing aqueous hydrochloric acid and the intermediate reaction product to obtain an organic phase comprising 4,4?-dichlorodiphenyl sulfoxide and an aqueous phase; (III) cooling the organic phase to a temperature below the saturation point of 4,4?-dichlorodiphenyl sulfoxide to obtain a suspension; (IV) solid-liquid-separation of the suspension to obtain crystallized 4,4?-dichlorodiphenyl sulfoxide, and mother liquor; (V) washing the crystallized 4,4?-dichlorodiphenyl sulfoxide with a carboxylic acid to obtain carboxylic acid-wet 4,4?-dichlorodiphenyl sulfoxide; (VI) reacting the washed 4,4?-dichlorodiphenyl sulfoxide and an oxidizing agent in a carboxylic acid as solvent to obtain a reaction mixture comprising 4,4?-dichlorodiphenyl sulfone and carboxylic acid; (VII) separating the react

Abstract: The invention relates to a process for working up a composition comprising solid 4,4?-dichlorodiphenyl sulfoxide and a solvent, wherein the amount of solvent in the composition is in the range between 5 and 25 wt % based on the total mass of the composition by washing the composition using a carboxylic acid until the amount of solvent in the composition is below 1.5 wt % based on the total amount of the composition after washing.

Abstract: The invention relates to a process for obtaining 4,4?-dichlorodiphenyl sulfoxide from a liquid mixture comprising dichlorodiphenyl sulfoxide and a solvent, comprising: (a) cooling the liquid mixture to a temperature below the saturation point of 4,4?-dichlorodiphenyl sulfoxide in the solvent to obtain a suspension comprising crystallized 4,4?-dichlorodiphenyl sulfoxide, (b) solid-liquid-separation of the suspension to obtain a residual moisture containing solid 4,4?-dichlorodiphenyl sulfoxide as a product and mother liquor, (c) concentrating the mother liquor, (d) recycling at least a part of the concentrated mother liquor into the cooling step (a).

Abstract: The invention relates to a process for producing 4,4?-dichlorodiphenyl sulfoxide comprising: (a) reacting thionyl chloride, chlorobenzene and aluminum chloride in a molar ratio of thionyl chloride:chlorobenzene:aluminum chloride of 1:(6 to 9):(1 to 1.5) at a temperature in the range from 0 to below 20° C., forming an intermediate reaction product and hydrogen chloride, (b) mixing aqueous hydrochloric acid and the intermediate reaction product at a temperature in the range from 70 to 110° C. to obtain a crude reaction product comprising 4,4?-dichlorodiphenyl sulfoxide, (c) separating the crude reaction product into an organic phase comprising the 4,4?-dichlorodiphenyl sulfoxide and an aqueous phase, (d) washing the organic phase with an extraction liquid.

Abstract: The invention relates to a process for purifying 4,4?-dichlorodiphenyl sulfoxide comprising: (a) providing a suspension comprising particulate 4,4?-dichlorodiphenyl sulfoxide in monochlorobenzene, (b) solid-liquid separation of the suspension to obtain residual moisture containing 4,4?-dichlorodiphenyl sulfoxide, (c) washing residual moisture containing 4,4?-dichlorodiphenyl sulfoxide with monochlorobenzene, (d) optionally repeating steps (a) to (c).

Abstract: The invention relates to a crystal (C) consisting of at least 95% by weight of 4,4?-dichlorodiphenylsulfoxide, 0 to 2% by weight of impurities and 0 to 3% by weight of an organic solvent (os). Moreover, the present invention relates to a crystal composition (CC) comprising crystals (C) and a process for the production of the crystal composition (CC) and the crystal (C).

Abstract: The invention relates to a process for producing 4,4?-dichlorodiphenyl sulfoxide comprising: (I) reacting thionyl chloride, chlorobenzene and aluminum chloride in a molar ratio of thionyl chloride:chlorobenzene:aluminum chloride of 1:(6 to 9):(1 to 1.5) at a temperature in the range from 0 to below 20° C., forming an intermediate reaction product and hydrogen chloride; (II) mixing aqueous hydrochloric acid and the intermediate reaction product at a temperature in the range from 70 to 110° C.

Abstract: The invention relates to a crystal (C) consisting of at least 95% by weight of 4,4?-dichlorodiphenylsulfoxide, 0 to 2% by weight of impurities and 0 to 3% by weight of an organic solvent (os). Moreover, the present invention relates to a crystal composition (CC) comprising crystals (C) and a process for the production of the crystal composition (CC) and the crystal (C).

Abstract: The invention relates to a crystal (C) consisting of at least 95% by weight of 4,4?-dichlorodiphenylsulfoxide, 0 to 2% by weight of impurities and 0 to 3% by weight of an organic solvent (os). Moreover, the present invention relates to a crystal composition (CC) comprising crystals (C) and a process for the production of the crystal composition (CC) and the crystal (C).

Abstract: A process for preparing water-absorbing polymer beads with high permeability by polymerizing droplets of a monomer solution, comprising monomers bearing acid groups, in a gas phase surrounding the droplets, wherein the monomer solution comprises polyvalent cations and the polymer beads have a mean diameter of at least 150 ?m.

Abstract: A process for preparing water-absorbing polymer beads with high permeability by polymerizing droplets of a monomer solution, comprising monomers bearing acid groups, in a gas phase surrounding the droplets, wherein the monomer solution comprises polyvalent cations and the polymer beads have a mean diameter of at least 150 ?m.

Abstract: A process for producing granules comprising one or more complexing agent salts of formula (I): from an aqueous starting solution, comprising the one or more complexing agent salts in a concentration of from 10 to 80% by weight, based on the total weight of the aqueous starting solution, in a jet apparatus.

Abstract: The present invention relates to a process for producing water-absorbent polymer particles by polymerizing droplets of a monomer solution in a surrounding heated gas phase and flowing the gas cocurrent through the polymerization chamber, wherein the temperature of the gas leaving the polymerization chamber is 130° C. or less, the gas velocity inside the polymerization chamber is at least 0.5 m/s, and the droplets are generated by using a droplet plate having a multitude of bores.

Abstract: A process for producing water-absorbing polymer particles by polymerizing droplets of a monomer solution in a surrounding gas phase in a reaction chamber, wherein the monomer solution is metered into the reaction chamber via at least one bore, and the diameter is from 210 to 290 ?m per bore and the metering rate is from 0.9 to 5 kg/h per bore.