Abstract: A process for producing alkyl methacrylates, in particular methyl methacrylate (MMA), includes production of methacrolein (MAL) in a first reaction stage; direct oxidative esterification (DOE) of the methacrolein with an alcohol, preferably methanol, to afford an alkyl methacrylate in a second reaction stage; and workup of the alkyl methacrylate crude product from the second reaction stage. An optimized workup of the reactor output from the oxidative esterification of methacrolein involves minimizing the amount of employed water, the amount of employed acid, and/or the amount of aqueous waste streams, through an optimized recycling of the generated process water streams.

Abstract: A process can be used for producing optical molding materials on the basis of methyl methacrylate (MMA). The MMA produced by an optimized method and the molding materials feature in particular a very low yellowness index. This MMA has been produced by direct oxidative esterification of methacrolein. An optimized workup of the reactor output from the oxidative esterification of methacrolein can be used for removing particularly discoloring byproducts. This process moreover has the advantage that fewer demands are placed on plant apparatus configuration.

Abstract: A process for producing alkyl methacrylates, in particular methyl methacrylate (MMA), includes production of methacrolein (MAL) in a first reaction stage; direct oxidative esterification (DOE) of the methacrolein with an alcohol, preferably methanol, to afford an alkyl methacrylate in a second reaction stage: and workup of the alkyl methacrylate crude product from the second reaction stage. An optimized workup of the reactor output from the oxidative esterification of methacrolein involves minimizing the amount of employed water, the amount of employed acid, and/or the amount of aqueous waste streams, through an optimized recycling of the generated process water streams.

Abstract: A process for producing alkyl methacrylates, in particular methyl methacrylate (MMA), includes production of methacrolein (MAL) in a first reaction stage; direct oxidative esterification (DOE) of the methacrolein with an alcohol, preferably methanol, to afford an alkyl methacrylate in a second reaction stage; and workup of the alkyl methacrylate crude product from the second reaction stage. An optimized workup of the reactor output from the oxidative esterification of methacrolein involves minimizing the amount of employed water, the amount of employed acid, and/or the amount of aqueous waste streams, through an optimized recycling of the generated process water streams.

Abstract: A process for producing alkyl methacrylates, in particular methyl methacrylate (MMA), includes production of methacrolein (MAL) in a first reaction stage; direct oxidative esterification (DOE) of the methacrolein with an alcohol, preferably methanol, to afford an alkyl methacrylate in a second reaction stage; and workup of the alkyl methacrylate crude product from the second reaction stage. An optimized workup of the reactor output from the oxidative esterification of methacrolein involves minimizing the amount of employed water, the amount of employed acid, and/or the amount of aqueous waste streams, through an optimized recycling of the generated process water streams.

Abstract: A process is useful for producing optical molding materials on the basis of methyl methacrylate (MMA), wherein this MMA has been produced by an optimized method and the molding materials feature in particular a very low yellowness index. This MMA has been produced by direct oxidative esterification of methacrolein. In particular, an optimized workup of the reactor output from the oxidative esterification of methacrolein is useful for removing particularly discoloring byproducts. This process moreover has the advantage that fewer demands than described in related art are placed on plant apparatus configuration.

Abstract: A process is useful for producing optical molding materials on the basis of methyl methacrylate (MMA), wherein this MMA has been produced by an optimized method and the molding materials feature in particular a very low yellowness index. This MMA has been produced by direct oxidative esterification of methacrolein. In particular, an optimized workup of the reactor output from the oxidative esterification of methacrolein is useful for removing particularly discoloring byproducts. This process moreover has the advantage that fewer demands than described in related art are placed on plant apparatus configuration.

Abstract: The present invention relates to an optimized process for the preparation of methacrolein. Methacrolein is used in chemical synthesis particularly as an intermediate for the preparation of methacrylic acid, methyl methacrylate or even active ingredients, fragrances or flavorings. In particular the present invention relates to the optimization of the process parameters by which, inter alia, a reduction of the content of harmful dimeric methacrolein in the end product may be achieved.

Abstract: The present invention relates to the oxidative combustion of amine-containing wastewaters, especially in a process for preparing methacrolein. Methacrolein is used in chemical synthesis particularly as an intermediate for preparation of methacrylic acid, methyl methacrylate, or else of active ingredients, odorants or flavorings. More particularly, the present invention relates to an oxidative combustion of the amine-containing wastewaters with only low nitrogen oxide formation.

Abstract: The present invention relates to an optimized process for the preparation of methacrolein. Methacrolein is used in chemical synthesis particularly as an intermediate for the preparation of methacrylic acid, methyl methacrylate or even active ingredients, fragrances or flavourings. In particular the present invention relates to the optimization of the process parameters by which, inter alia, a reduction of the content of harmful dimeric methacrolein in the end product may be achieved.

Abstract: The present invention concerns regulating the water content in a process for production of methacrolein. Methacrolein is used in chemical synthesis particularly as an intermediate for production of methacrylic acid, methyl methacrylate or else of active, aroma or flavor chemicals. The present invention is particularly concerned with regulating the water content in a process for production of methacrolein from formaldehyde and propionaldehyde via a Mannich condensation.

Abstract: The present invention concerns regulating the water content in a process for production of methacrolein. Methacrolein is used in chemical synthesis particularly as an intermediate for production of methacrylic acid, methyl methacrylate or else of active, aroma or flavour chemicals. The present invention is particularly concerned with regulating the water content in a process for production of methacrolein from formaldehyde and propionaldehyde via a Mannich condensation.

Abstract: The present invention relates to the oxidative combustion of amine-containing wastewaters, especially in a process for preparing methacrolein. Methacrolein is used in chemical synthesis particularly as an intermediate for preparation of methacrylic acid, methyl methacrylate, or else of active ingredients, odorants or flavorings. More particularly, the present invention relates to an oxidative combustion of the amine-containing wastewaters with only low nitrogen oxide formation.

Abstract: This invention relates to a process of preparing highly pure, non-yellowing (meth)acrylic acid necessary for high-tech applications requiring long-tem color stability in the presence of amines. Process for the preparation of highly pure, non-yellowing (meth)acrylic acid comprising the steps: f) Condensation of a (meth)acrylic acid-containing gas phase obtained via a gas phase oxidation process of a C4-compound to generate an aqueous (meth)acrylic acid solution g) Separation of the (meth)acrylic acid from the aqueous (meth)acrylic acid solution to obtain crude (meth)acrylic acid h) Rectification of the crude (meth)acrylic acid to obtain pure (meth)acrylic acid via a sidestream outlet of the rectification column i) Treatment of the pure (meth)acrylic acid generated in step c) with an ion exchange resin j) Distillation of the (meth)acrylic acid generated in step d).

Abstract: This invention relates to a process of preparing highly pure, non-yellowing (meth)acrylic acid necessary for high-tech applications requiring long-tem color stability in the presence of amines. Process for the preparation of highly pure, non-yellowing (meth)acrylic acid comprising the steps: f) Condensation of a (meth)acrylic acid-containing gas phase obtained via a gas phase oxidation process of a C4-compound to generate an aqueous (meth)acrylic acid solution g) Separation of the (meth)acrylic acid from the aqueous (meth)acrylic acid solution to obtain crude (meth)acrylic acid h) Rectification of the crude (meth)acrylic acid to obtain pure (meth)acrylic acid via a sidestream outlet of the rectification column i) Treatment of the pure (meth)acrylic acid generated in step c) with an ion exchange resin j) Distillation of the (meth)acrylic acid generated in step d).

Abstract: The present invention relates to a process for preparing ethylene glycol dimethacrylate, which comprises transesterification of ethylene glycol with an ester of methacrylic acid in the presence of catalysts, wherein a combination comprising lithium amide (LiNH2) and lithium chloride (LiCl) is used as catalyst. The process of the invention makes it possible to prepare ethylene glycol dimethacrylate particularly inexpensively and in a very high purity.

Abstract: The invention relates to a process for continuously preparing N-alkyl(meth)acrylamides by reacting alkyl(meth)acrylates with high-boiling amines. A catalyst activation and specific workup technique achieve product qualities which have not been achieved to date. In addition, very high space-time yields and overall yields can be achieved.

Abstract: The present invention relates to a process for preparing ethylene glycol dimethacrylate, which comprises transesterification of ethylene glycol with an ester of methacrylic acid in the presence of catalysts, wherein a combination comprising lithium amide (LiNH2) and lithium chloride (LiCl) is used as catalyst. The process of the invention makes it possible to prepare ethylene glycol dimethacrylate particularly inexpensively and in a very high purity.

Abstract: The present invention relates to a process for preparation of pure methacrylic acid, at least comprising the process steps: a) gas phase oxidation of a C4 compound to obtain a methacrylic acid-comprising gas phase, b) condensation of the methacrylic acid-comprising gas phase to obtain an aqueous methacrylic acid solution, c) separation of at least a part of the methacrylic acid from the aqueous methacrylic acid solution to obtain at least one crude methacrylic acid-comprising product; d) separation of at least a part of the methacrylic acid from the at least one crude methacrylic acid-comprising product by means of a thermal separation process to obtain a pure methacrylic acid.

Abstract: The invention relates to a process for continuously preparing N-alkyl(meth)acrylamides by reacting alkyl (meth)acrylates with high-boiling amines. A catalyst activation and specific workup technique achieve product qualities which have not been achieved to date. In addition, very high space-time yields and overall yields can be achieved.