Abstract: The present invention relates to a process for preparing tertiary alkyl esters of (meth)acrylic acid having at least 4 carbon atoms in the alkyl radical. The process includes reacting (meth)acrylic acid with at least one olefin of formula (I) in homogeneous phase in the presence of an acidic catalyst in a reactor, discharging the resulting reaction mixture from the reactor, separating the discharged reaction mixture into a first mixture which contains the catalyst and a second mixture which contains the tertiary alkyl ester of (meth)acrylic acid having at least 4 carbon atoms in the alkyl radical, and removing the tertiary alkyl ester of (meth)acrylic acid having at least 4 carbon atoms in the alkyl radical from the second mixture in the presence of compound S, which comprises at least one N-oxyl group and is added as a stabilizer.

Abstract: A process for transferring heat to a liquid mixture comprising at least one (meth)acrylic monomer in an indirect heat exchanger, wherein a quaternary ammonium salt, a tertiary amine or a salt thereof with a Brønsted acid is added to the liquid mixture to reduce fouling.

Abstract: A process for separating acrylic acid present as a main product and glyoxal present as a by-product in a product gas mixture of a partial gas phase oxidation of a C3 precursor compound, in which a liquid phase P is obtained, which consists of acrylic acid to an extent of at least 70% of its weight and, based on the molar amount of acrylic acid present therein, comprises at least 200 molar ppm of glyoxal, in which the glyoxal is separated from the acrylic acid in the liquid phase P by crystallization.

Abstract: A process for transferring heat to a liquid F comprising dissolved monomeric acrylic acid, Michael acrylic acid oligomers, and acrylic acid polymer with the aid of an indirect heat exchanger to which are supplied the liquid F with a temperature TF of ?150° C. and a fluid heat carrier W with a temperature of TW>TF, wherein the formation of gas bubbles and/or of thin layers of liquid F adjoining a gas phase is brought about in the liquid F during the flow through the heat exchanger.

Abstract: A process for preparing tertiary alkyl esters of (meth)acrylic acid having at least 4 carbon atoms in the alkyl radical, comprising the steps of: (1) reacting (meth)acrylic acid with at least one olefin of the general formula I: in which R1 and R2 are an alkyl radical, and R3 is a hydrogen atom, an alkyl radical, a cycloalkyl radical, an aryl radical, an alkylcycloalkyl radical, an alkylaryl radical, a cycloalkylaryl radical, or an alkylcycloalkylaryl radical; in homogeneous phase in the presence of an acidic catalyst in a reactor, (2) discharging the resulting reaction mixture (1) from the reactor, (3) separating the discharged reaction mixture (2) into a mixture (3.1) which comprises the catalyst and a mixture (3.2) which comprises the tertiary alkyl ester of (meth)acrylic acid having at least 4 carbon atoms in the alkyl radical, and (4) removing the tertiary alkyl ester of (meth)acrylic acid having at least 4 carbon atoms in the alkyl radical from the mixture (3.

Abstract: A process for transferring heat to a liquid mixture comprising at least one (meth)acrylic monomer in an indirect heat exchanger, wherein a quaternary ammonium salt, a tertiary amine or a salt thereof with a Brønsted acid is added to the liquid mixture to reduce fouling.