Basf Aktiengesellschaft

Dresser Industries, Inc.

Gerhard Schaefer

Peter Neumann

Dietmar Nissen

Hubert Sauter

Wolfgang Siegel

Gerhard Heinz

Heinz Eilingsfeld

Helmut Tesch

Herbert Stutz

Hartmut Zeiner

Michael Stumpp

Walter Doerflinger

Manfred Heym

Jurgen Fischer

Preparation of mixtures of (R)- and (S)-2-(4-alkanoylphenoxy)- or (R)-

A process for the isolation of 4,4'-dichlorodiphenyl sulfone from a mixture of dichlorodiphenyl sulfones in which the ratios of the masses of 2,4'-dichlorodiphenyl sulfone and 3,4'-dichlorodiphenyl sulfone to the mass of 4,4'-dichlorodiphenyl sulfone are respectively from 0.5% to 20% and from 0.5% to 30% by treating the mixture with an alkanol at temperatures of from 20.degree. C. to 250.degree. C., cooling, and separating the pure 4,4'-dichlorodiphenyl sulfone that precipitates.

Isolation of 4,4'-dichlorodiphenyl sulfone

A process for the preparation of 4,4-dichlorodiphenyl sulfone by heating a mixture of (a) chlorobenzene, (b) chlorosulfonic acid or sulfur trioxide, and (c) thionyl chloride or phosgene to temperatures up to 220.degree. C., more than the stoichiometric amount (based on the amount of chlorobenzene) of chlorosulfonic acid or sulfur trioxide and less than the stoichiometric amount of thionyl chloride or phosgene being employed.

Preparation of 4,4' dichlorodiphenyl sulfone

A solvent-free curable composition has a long shelf life and consists of

Curable compositions based on epoxy resins

Fiber-reinforced materials are produced by impregnating continuous filaments with a melt of a polyarylene sulfide ketone, preferably one having a reduced viscosity .eta..sub.red of from 0.1 to 0.5 [dl.g.sup.-1 ], shaping the resulting semi-finished product to give a finished article and heating the latter for not less than 15 minutes at above the crystallite melting point of the polyarylene sulfide ketone, the latter undergoing crosslinking and its glass transition temperature Tg increasing by not less than 5.degree. C.

Production of fiber-reinforced materials

Growing community of inventors

Heidelberg, Germany

Gerhard Schaefer