Basf Aktiengesellschaft

Basf Se Corporation

Friedrich-Georg Martin

Hartmut Hibst

Andreas Tenten

Ulrich Hammon

Klaus Joachim Mueller-Engel

Peter Zehner

Peter Zurowski

Michael Blechschmitt

Rüdiger Funk

Gerhard Nestler

Sylke Haremza

Volker Schliephake

Uwe Stueven

Klaus Joachim Müller-Engel

Laszlo Marosi

Jürgen Schröder

J&uuml;rgen Schr&ouml;der

Hans-Peter Neumann

Christof Kujat

Karolin Geyer

Steffen Rissel

Thorsten Friese

Armin Schraut

Nikolaus Nestle

Till Blum

Ann-Kathrin Marguerre

Christian Raith

Murat Cetinkaya

Tobias Johannes Korn

Oliver Odenwald

Ulrich Jäger

Daher Michael Badine

Veronika Kohl

Ansgar Schaefer

Eduard Schreiner

Reiner Weiler

Josef Wekerle

A composition for the immediate stopping of a free-radical polymerization comprises a) an inhibitor for the free-radical polymerization selected from among phenothiazines, b) an aprotic solvent and c) an ionic liquid. It serves to stabilize free-radically polymerizable monomers against free-radical polymerization. For the immediate stopping of free-radical polymerizations, the composition is added to a free-radically polymerizing system.

Composition for the immediate stopping of a free-radical polymerization

The present invention relates to a process for restabilizing free-radically polymerizable monomers. The process comprises the steps: (a) introduction of a solution of an inhibitor of the free-radical polymerization by means of an inert pressurized gas into a vessel () comprising the monomers via a line () which comprises an ascending region, and (b) mixing of the contents of the vessel and the inhibitor solution by blowing gas through the line (). In step (a), the flow velocity of the pressurized gas is set so that plug flow or annular flow is obtained as flow regime of the inhibitor solution and in step (b) the superficial gas velocity is set to &#x2265;0.1 mm/s. The present invention further relates to a supply unit () for carrying out the process.

Process and supply unit for restabilizing free-radically polymerizable monomers

A process for inhibiting unwanted free-radical polymerization of acrylic acid present in a liquid phase P whose acrylic acid content is at least 10% by weight and which, based on the weight of the acrylic acid present therein, additionally comprises at least 100 ppm by weight of propionic acid and at least 100 ppm by weight of glyoxal, in which at least one chemical compound of the element copper is added to the liquid phase P, and the resulting liquid phases P to which a chemical compound of the element copper has been added.

Process for inhibiting unwanted free-radical polymerization of acrylic acid present in a liquid phase P

A process for mixing a liquid stored in a vessel, in which gas is sucked in from the gas phase present above the liquid interface with a suction apparatus present in the liquid, and released into it again for the gas-induced mixing of the liquid.

Process for mixing a liquid or mixture of a liquid and a fine solid present in an essentially self-containing vessel

A process for mixing a liquid or mixture of a liquid and a fine solid present in a vessel, in which the vessel is supplied with the same liquid or the same mixture as a motive jet of a jet nozzle which is present in the vessel and has a motive jet and a momentum exchange chamber, the suction region between motive nozzle and momentum exchange chamber being provided with a sheath which has a suction orifice below the central jet leading from the motive nozzle into the momentum exchange chamber.

The invention relates to processes for preparing water absorbing polymers by polymerization of a monomer solution comprising allyl acrylate and/or allyl alcohol, the solution comprising not more than 0.002% by weight of allyl acrylate and/or allyl alcohol, based on acrylic acid, to aqueous monomer solutions for producing water absorbing polymers, to water absorbing polymers, to processes for producing hygiene articles and also to hygiene articles.

Method for producing water-absorbing polymers

The invention relates to a method for producing (meth)acrylic acid esters by transesterification of the (meth)acrylic acid with a higher alkanol in the presence of an acid catalyst, at least one polymerization inhibitor and one organic solvent that forms an azeotropic mixture with water. The reaction mixture is heated to the boiling point of the mixture in a reactor that comprises a distillation unit with a column and a condenser. The content of the reactor is recirculated via an external evaporator and heated to the boiling point, and the azeotropic mixture is distilled off. The organic solvent forms a reflux and at least a part of the solvent reflux is recirculated between the reactor and the evaporator. The inventive method allows for the production of higher (meth)acrylic acid esters in a reactor with a circulation evaporator without using copper salts as the polymerization inhibitors.

Method for producing higher (meth)acrylic acid esters

In the preparation of esters of acrylic or methacrylic acid by esterification with alcohols, the interfering deposits formed on the apparatus parts by relatively high molecular weight by-products can be avoided, removed or lessened by allowing a liquid partly or wholly consisting of the alcohol used for the esterification to act on the deposits, fouled apparatus parts or on the surfaces of the apparatus parts on which deposits are easily formed, with preference being given to wetting the deposits or surfaces using suitable nozzles or cleaning sprayers.

Method for preventing, removing or reducing deposits in apparatus parts during the esterification of acrylic or methacrylic acids

Polymetal oxide materials of the general formula I

Polymetal oxide materials

Multimetal oxide compositions having a two-phase structure and comprising molybdenum, hydrogen, one or more of the elements phosphorus, arsenic, boron, germanium and silicon, and their use for the preparation of methacrylic acid by gas-phase catalytic oxidation.

Multimetal oxide compositions

Multimetal oxide compositions having a two-phase structure and comprising molybdenum, hydrogen, one or more of the elements phosphorus, arsenic, boron, germanium and silicon, and copper, and their use for the preparation of methacrylic acid by gas-phase catalytic oxidation.

Multimetal oxide compositions having a two-phase structure and comprising molybdenum, hydrogen, one or more of the elements phosphorus, arsenic, boron, germanium and silicon, one or more of the elements niobium, tantalum and antimony and one or more of the elements copper, iron, cobalt, nickel, zinc, cadmium, manganese, magnesium, calcium, strontium and barium, and their use for the preparation of methacrylic acid by gas-phase catalytic oxidation.

Growing community of inventors

Heidelberg, Germany

Friedrich-Georg Martin