Evonik Roehm Gmbh

Evonik Rohm Gmbh

John Hirsh

Joachim Knebel

Wolfgang Klesse

Dieter Tessmer

Gerold Schmitt

Guido Protzmann

Volker Kerscher

Ralf Merbach

Klaus Gottmann

Wilhelm Karnbrock

Process for preparing (meth)acrylates of the formula (I)CH&#x2550;C(R)&#x2014;CO&#x2014;O&#x2014;R&#x2003;&#x2003;(I)in which Ris hydrogen or methyl andRis a saturated or unsaturated, linear or branched, aliphatic or cyclic alkyl radical having 6 to 22 carbon atoms, or a (C-C)-aryl-(C-C)-alkyl radical;by reacting a (meth)acrylate of the formula IICH&#x2550;C(R)&#x2014;CO&#x2014;OR&#x2003;&#x2003;(II)with an alcohol of the formula (III)HO&#x2014;R&#x2003;&#x2003;(III)in the presence of an amount of a suitable catalyst which catalyzes the reaction and of an amount of a phenolic polymerization inhibitor or a combination of two or more phenolic polymerization inhibitors which is sufficient to inhibit undesired polymerization;the reaction being undertaken with input or introduction into the reaction mixture resulting from the reaction of an amount of oxygen or of an oxygenous gas mixture sufficient to inhibit undesired polymerization, and the process is characterized in thatthe specific total oxygen input is less than or equal to 1.0 l/kg, measured in liters of oxygen per kilogram of (meth)acrylate of the formula (I), where the volume of oxygen introduced is calculated at a temperature of 25&#xb0; C. and a pressure of 101 325 pascal. The resulting (meth)acrylates can surprisingly be processed to particularly high molecular weight emulsion polymers which are, for example, outstandingly suitable for use as flow resistance reducers in mineral oil extraction.

Process for preparing (meth)acrylates

Process for preparing (meth)acrylates of the formula (I)CH&#x2550;C(R)&#x2014;CO&#x2014;O&#x2014;R&#x2003;&#x2003;(I) The resulting (meth)acrylates can surprisingly be processed to particularly high molecular weight emulsion polymers which are, for example, outstandingly suitable for use as flow resistance reducers in mineral oil extraction.

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Fairhope, AL, United States of America

John Hirsh