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 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 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.; (e) optionally repeating steps (b) to (d); (f) drying the 4,4′-dichlorodiphenyl sulfone.
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 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 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 present invention relates to a process for the preparation of a polyarylether copolymer (P), the polyarylether copolymer (P) obtained by the process and a process for the preparation of a membrane comprising the polyaryl-ether copolymer (P) and the membrane itself.
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 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. to obtain an organic phase comprising 4,4′-dichlorodiphenyl sulfoxide and an aqueous phase; (III) cooling the organic phase comprising the 4,4′-dichlorodiphenyl sulfoxide to a temperature below the saturation point of 4,4′-dichlorodiphenyl sulfoxide to obtain a suspension comprising crystallized 4,4′-dichlorodiphenyl sulfoxide; (IV) solid-liquid-separation of the suspension to obtain a residual moisture containing solid 4,4′-dichlorodiphenyl sulfoxide comprising crystallized 4,4′-dichlorodiphenyl sulfoxide and mother liquor.
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.