The presence of certain impurities in diphenyl sulfone have a deleterious effect on the properties of the poly(aryletherketone)s produced therein, including one or more of color, melt stability, molecular weight, crystallinity, etc. and here identify those impurities and provide processes for the recovery of the diphenyl sulfone.

The presence of certain impurities in diphenyl sulfone have a deleterious effect on the properties of the poly(aryletherketone)s produced therein, including one or more of color, melt stability, molecular weight, crystallinity, etc. and here identify those impurities and provide processes for the recovery of the diphenyl sulfone.

A curing agent composition contains at least one multifunctional aromatic amine that forms a crystalline solid at 25° C., and at least one halo-substituted diethyltoluenediamine, in an amount effective to inhibit crystallization of the at least one multifunctional aromatic amine. A curable resin composition contains at least one epoxy compound having at least two epoxide groups per molecule of the epoxy compound and the curing agent composition. Methods for inhibiting phase separation of a curing agent composition or curable resin composition that contains at least one multifunctional aromatic amine that forms a crystalline solid at 25° C. include a step of adding to the respective composition at least one halo-substituted diethyltoluenediamine in an amount effective to inhibit crystallization of the at least one multifunctional aromatic amine. The compositions and methods are useful in making fiber reinforced resin matrix composite articles.

A curing agent composition contains at least one multifunctional aromatic amine that forms a crystalline solid at 25° C., and at least one halo-substituted diethyltoluenediamine, in an amount effective to inhibit crystallization of the at least one multifunctional aromatic amine. A curable resin composition contains at least one epoxy compound having at least two epoxide groups per molecule of the epoxy compound and the curing agent composition. Methods for inhibiting phase separation of a curing agent composition or curable resin composition that contains at least one multifunctional aromatic amine that forms a crystalline solid at 25° C. include a step of adding to the respective composition at least one halo-substituted diethyltoluenediamine in an amount effective to inhibit crystallization of the at least one multifunctional aromatic amine. The compositions and methods are useful in making fiber reinforced resin matrix composite articles.

A curing agent composition contains at least one multifunctional aromatic amine that forms a crystalline solid at 25° C., and at least one halo-substituted diethyltoluenediamine, in an amount effective to inhibit crystallization of the at least one multifunctional aromatic amine. A curable resin composition contains at least one epoxy compound having at least two epoxide groups per molecule of the epoxy compound and the curing agent composition. Methods for inhibiting phase separation of a curing agent composition or curable resin composition that contains at least one multifunctional aromatic amine that forms a crystalline solid at 25° C. include a step of adding to the respective composition at least one halo-substituted diethyltoluenediamine in an amount effective to inhibit crystallization of the at least one multifunctional aromatic amine. The compositions and methods are useful in making fiber reinforced resin matrix composite articles.

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).

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).

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).

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.

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.