Abstract: A process for enriching acetic acid from aqueous acetic acid mixtures containing other lower carboxylic acids such as formic acid, propionic acid and butyric acid by crystallization.

Abstract: Method for stabilizing polyvinylpyrrolidones, which comprises treating the polyvinylpyrrolidones with sulfur dioxide, sulfurous acid or alkali metal sulfites and then with free-radical scavenger, and converting the solutions treated in this way into the powdered polyvinylpyrrolidones by drying.

Abstract: Provided is a process for preparing a (meth)acrylic ester (F) of an N-hydroxyalkylated lactam, in which a cyclic N-hydroxyalkylated lactam (L): where the structural variables as defined herein, in the presence of at least one metal salt of C1-C10-alkoxides (A), is esterified with (meth)acrylic acid (S) or transesterified with at least one (meth)acrylic ester (D), in which the metal salt of C1-C10-alkoxides (A) used as a catalyst is added in the absence of solvents and completely at the start of the reaction.

Abstract: A process for catalytically preparing (meth)acrylic esters of N-hydroxyalkylated lactams and to the use thereof.

Abstract: Process for preparing (meth)acrylates of C10-alcohol mixtures, by reacting (meth)acrylic acid with an isomer mixture of C10-alcohols composed of 2-propylheptanol as the main isomer and at least one of the C10-alcohols 2-propyl-4-methylhexanol, 2-propyl-5-methylhexanol, 2-isopropylheptanol, 2-isopropyl-4-methylhexanol, 2-isopropyl-5-methylhexanol and/or 2-propyl-4,4-dimethylpentanol, in the presence of at least one acidic catalyst and of at least one polymerization inhibitor and in the presence of a solvent which forms an azeotrope with water, the azeotrope is distilled off and condensed, and the condensate splits into an aqueous phase and an organic phase, wherein a) the esterification is performed in a reactor with a circulation evaporator and b) in the presence of a solvent, and c) the crude product is purified by subsequent purifying distillation.

Abstract: The claimed invention relates to a process for preparing (meth)acrylates of N-hydroxyalkylated amides, in which open-chain N-hydroxyalkylated amides are esterified with (meth)acrylic acid or transesterified with at least one (meth)acrylic ester in the presence of at least one heterogeneous catalyst selected from the group consisting of an inorganic salt and an enzyme.

Abstract: The present invention relates to a process for preparing (meth)acrylic esters (F) of N,N-substituted amino alcohols, by transesterifying N,N-substituted amino alcohols (I) in which Y and Z are each independently C1-C20-alkyl, C3-C15-cycloalkyl, aryl, or Y and Z together with the nitrogen atom connecting them form a 5- to 9-membered saturated heterocyclic radical which optionally has oxygen, sulfur, nitrogen or C1-C4-alkyl-substituted nitrogen as a further heteroatom, and X is C2-C20-alkylene which may be interrupted by 1 to 10 nonadjacent oxy groups and/or unsubstituted or methoxy-substituted C1-C4-alkylimino groups, or a C3-C15-cycloalkylene, with at least one (meth)acrylic ester (D) in the presence of at least one heterogeneous catalyst (K), wherein the heterogeneous catalyst (K) is used without any further solvent and the content of polymerization inhibitors in the reaction mixture is <450 ppm, and to the use of the (meth)acrylic esters (F) of N,N-substituted amino alcohols.

Abstract: A process for preparing (meth)acrylic esters (F) of N-hydroxyalkylated imidazoles, wherein N-hydroxyalkylated imidazoles (I), in which R1 and R2 may each independently be hydrogen or C1-C20-alkyl, R3, R4 and R5 are each independently hydrogen or C1-C20-alkyl, C1-C20-alkylcarbonyl, C2-C20-alkenyl, C2-C20-alkenylcarbonyl, C2-C20-alkynyl, C2-C20-alkynylcarbonyl, C3-C15-cycloalkyl, C3-C15-cycloalkylcarbonyl, aryl, arylcarbonyl, a heterocycle or a halogen atom, and m and n are each integers in the range of in each case from 0 to 20, where m and n cannot simultaneously be 0, and in which the particular units bracketed by the variables m and n are present in any sequence, and in which, in the case that m?2, the R1 and R2 radicals are in each case independent in the particular units, in the presence of at least one catalyst (K), are esterified with (meth)acrylic acid (S) or transesterified with at least one (meth)acrylic ester (D).

Abstract: The claimed invention relates to a process for preparing (meth)acrylates of N-hydroxyalkylated amides, in which open-chain N-hydroxyalkylated amides are esterified with (meth)acrylic acid or transesterified with at least one (meth)acrylic ester in the presence of at least one heterogeneous catalyst selected from the group consisting of an inorganic salt and an enzyme.

Abstract: The claimed invention relates to a process for preparing (meth)acrylates of N-hydroxyalkylated amides, in which open-chain N-hydroxyalkylated amides are esterified with (meth)acrylic acid or transesterified with at least one (meth)acrylic ester in the presence of at least one heterogeneous catalyst selected from the group consisting of an inorganic salt and an enzyme.

Abstract: A process for removal of a crude acrylic acid from a product gas mixture which comprises glyoxal as a by-product from a heterogeneously catalyzed partial gas phase oxidation of at least one C3 precursor compound, which comprises the absorption of the acrylic acid in a high-boiling absorbent and the rectificative workup of the resulting adsorbate, and in which absorbent present in the bottoms liquid withdrawn from the bottom space of the absorption column is distilled off in a distillation unit and recycled into the absorption, before high boilers which remain are discharged, and in which the glyoxal content of the crude acrylic acid is reduced by restricting the high boiler residence time in the distillation unit.

Abstract: Process for preparing (meth)acrylates of C10-alcohol mixtures, by reacting (meth)acrylic acid with an isomer mixture of C10-alcohols composed of 2-propylheptanol as the main isomer and at least one of the C10-alcohols 2-propyl-4-methylhexanol, 2-propyl-5-methylhexanol, 2-isopropylheptanol, 2-isopropyl-4-methylhexanol, 2-isopropyl-5-methylhexanol and/or 2-propyl-4,4-dimethylpentanol, in the presence of at least one acidic catalyst and of at least one polymerization inhibitor and in the presence of a solvent which forms an azeotrope with water, the azeotrope is distilled off and condensed, and the condensate splits into an aqueous phase and an organic phase, wherein a) the esterification is performed in a reactor with a circulation evaporator and b) in the presence of a solvent, and c) the crude product is purified by subsequent purifying distillation.

Abstract: The claimed invention relates to a process for preparing (meth)acrylates of N-hydroxyalkylated amides, in which open-chain N-hydroxyalkylated amides are esterified with (meth)acrylic acid or transesterified with at least one (meth)acrylic ester in the presence of at least one heterogeneous catalyst selected from the group consisting of an inorganic salt and an enzyme.

Abstract: Process for catalytically preparing (meth)acrylates of N-hydroxyalkylated lactams, and use thereof.

Abstract: A process for preparing (meth)acrylic esters (F) of N-hydroxyalkylated lactams, in which cyclic N-hydroxyalkylated lactams (L) in which R1 is C1-C5-alkylene, or C2-C20-alkylene interrupted by one or more oxygen and/or sulfur atoms and/or one or more substituted or unsubstituted imino groups and/or by one or more cycloalkyl, —(CO)—, —O(CO)O—, —(NH)(CO)O—, —O(CO)(NH)—, —O(CO)— or —(CO)O— groups, where the radicals mentioned may each be substituted by aryl, alkyl, aryloxy, alkyloxy, heteroatoms and/or heterocycles, with the proviso that R1 must not have any atom other than a carbon atom directly adjacent to the lactam carbonyl group, R2 is C1-C20-alkylene, C5-C12-cycloalkylene, C6-C12-arylene, or C2-C20-alkylene interrupted by one or more oxygen and/or sulfur atoms and/or one or more substituted or unsubstituted imino groups and/or by one or more cycloalkyl, —(CO)—, —O(CO)O—, —(NH)(CO)O—, —O(CO)(NH)—, —O(CO)— or —(CO)O— groups, where the radicals mentioned may each be substituted by aryl, alkyl, aryloxy, al

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 preparing N-alkenyl compounds by reacting the corresponding NH compounds with alkynes in the liquid phase in the presence of a catalyst, wherein the reaction is carried out in the presence of at least one stabilizer, and the use of stabilizers for increasing the selectivity in a process for preparing N-alkenyl compounds by reacting the corresponding NH compounds with alkynes in the liquid phase in the presence of a catalyst.

Abstract: An absorption medium for deacidifying fluid streams which has improved oxidation stability includes at least one aliphatic amine, and at least one non-hydroquinoid antioxidant. The absorption medium may be employed in deacidifying a fluid stream, in particular an oxygen-containing fluid stream, when the fluid stream is brought into intimate contact with the absorption medium in at least one absorption step.

Abstract: A process for preparing (meth)acrylic esters (F) of N-hydroxyalkylated lactams, in which cyclic N-hydroxyalkylated lactams (L) in which R1 is C1-C5-alkylene, or C2-C20-alkylene interrupted by one or more oxygen and/or sulfur atoms and/or one or more substituted or unsubstituted imino groups and/or by one or more cycloalkyl, —(CO)—, —O(CO)O—, —(NH)(CO)O—, —O(CO)(NH)—, —O(CO)— or —(CO)O— groups, where the radicals mentioned may each be substituted by aryl, alkyl, aryloxy, alkyloxy, heteroatoms and/or heterocycles, with the proviso that R1 must not have any atom other than a carbon atom directly adjacent to the lactam carbonyl group, R2 is C1-C20-alkylene, C5-C12-cycloalkylene, C6-C12-arylene, or C2-C20-alkylene interrupted by one or more oxygen and/or sulfur atoms and/or one or more substituted or unsubstituted imino groups and/or by one or more cycloalkyl, —(CO)—, —O(CO)O—, —(NH)(CO)O—, —O(CO)(NH)—, —O(CO)— or —(CO)O— groups, where the radicals mentioned may each be substituted by aryl, alkyl, aryloxy, alk

Abstract: A process for rectificatively separating an acrylic acid-containing liquid, by withdrawing an acrylic acid-rich stream from the rectification column above the feed point and polymerization-inhibiting the upper section of the rectification column by means of diacrylic acid.