Rohm Gmbh

Roehm Gmbh Chemische Fabrik

Ruediger Jelitte

Horst Pennewiss

Claudia Beyer

Clemens Auschra

Klaus Langerbeins

Heinz Jost

Gerhard Emig

Wolfgang Ruppert

Juergen Omeis

Bernhard Will

Otto Watzenberger

The invention relates to polymer emulsions of poly(meth)acrylic acid esters and olefin copolymers suitable for improvement of the viscosity index, for use as oil additives. The polymer emulsion is formed of a continuous phase of poly(meth)acrylic acid esters and d-oligomers where the esters and oligomers have a bimodal molecular-weight distribution, a stabilizing agent (a graft or block polymerizate of an olefin copolymerizate and methacrylic acid esters), and a disperse phase of olefin copolymerizates distributed in the continuous phase.

Polymer emulsions with bimodal molecular-weight distribution

Synthetic oils comprising 5-100 percent by weight of an oligomer of

Synthetic oligomeric oils

The invention relates to the stabilization of the activity and/or the reactivation of molybdoheteropoly acid catalysts in vapor-phase oxidations, such as the oxidehydrogenation of isobutyric acid or its lower esters to methacrylic acid or its lower esters, by means of an oxidizing treatment of the catalyst in which compounds of catalyst constituents are added, at temperatures ranging from 200.degree. to 400.degree. C., with an oxygen-containing gas. The inventive activation measures can be carried out either during the catalytic vapor-phase reaction, such as oxihydrogenation in particular, or intermittently to alternate therewith, and optionally also physically separated in part from each other.

Method for the catalytic vapor phase oxydehydrogenation of isobutyric

Growing community of inventors

Rossdorf, Germany

Ruediger Jelitte