Abstract: A process for performing a heterogeneously catalysed reaction for the oxidative esterification of aldehydes to carboxylic esters can be performed. Against this background, the process has made it possible to keep the heterogeneous, precious metal catalyst used in this method active during operation in a particularly effective manner, in order to lengthen the period between downtimes and to effect particularly sustainable catalyst management. This gives rise to the possibility of performing such processes in a very simple, economically viable and environmentally benign manner.

Abstract: Polymer compositions are made based on imidated polyalkyl (meth)acrylate, especially imidated polymethyl methacrylate. The polymer composition includes a polymer matrix A and at least one tribological additive B, especially selected from organic or inorganic solid hardening particles. The polymer compositions and formed articles made thereof exhibit low friction coefficients and high wear resistance even at elevated temperatures. They can advantageously be used in tribological application, in replacement of high-performance materials, such as polyether ether ketone (PEEK).

Abstract: An opaque lightly coloured thermoplastic moulding composition is made having improved long-term weathering stability as well as excellent optical appearance, especially high colour brilliance. The thermoplastic moulding compositions include the combination of an inorganic pigment and an organic soluble dye, wherein the inorganic pigment is selected from specific mixed metal oxides and mixed metal oxosulfides. A process is also made to produce the coloured moulding composition. Colouring compositions, such as masterbatches, which can be used for producing the coloured thermoplastic moulding composition are further developed. Opaque lightly coloured formed articles are finally made from the thermoplastic moulding composition, for example injection moulded articles and extruded articles.

Abstract: A transparent acrylic-based polymer composition having an increased resistance to alcohols, oils and fats can be made. The polymer composition has an acrylic-based polymer A, which has at least one alkyl (meth) acrylate; an olefinic copolymer B, which has at least one olefinic monomer and at least one polar monomer selected from unsaturated carboxylic acids, esters of unsaturated carboxylic acids, and anhydrides of unsaturated carboxylic acids, and a particulate multiphase graft copolymer C, which has a core and at least one shell, having at least one alkyl (meth) acrylate.

Abstract: A process for preparing (meth)acrylate-based reactive resins involves mixing at least one polymer component and a monomer component. The reactive resins, especially (meth)acrylate resins, as are useful as a component, for example, in two-component systems employed as road marking, floor coating, or sealant. A particular feature of the new process is that its use can bring about increased product safety and stability both during preparation and during storage and transport.

Abstract: A reactive resin system for intumescent coating can be made. Intumescent coatings are used for fire protection of metallic building components. In the event of a fire, said coatings undergo reactive foaming that results in the formation on the metal girder of a fireproof insulating layer having low thermal conductivity and that retards any early, thermally induced failure of said building component. A methacrylate-based resin system is produced by a process in which a first monomer fraction is polymerized to a maximum degree of 95% by weight and diluted with a second monomer mixture. The glass transition temperature of the polymeric component of the composition that is formed is low compared with the art. Organic acids incorporated into the resin system have synergistic effect with the filler system. The resin systems produced are found to be efficient at thermally induced foaming, because of their fine-pored and closed-pored foam structure.

Abstract: A process can be used for preparing methyl methacrylate (MMA), by direct oxidative esterification of methacrolein. The MMA and polymers produced therefrom feature a very low yellowness index. A workup of the reactor output from the oxidative esterification of methacrolein allows for particularly discolouring by-products to be removed or degraded without significant MMA losses.

Abstract: A clamping jaw for a chuck includes a jaw body on which there is formed at least one jaw step having a step head, which has a sensor on its end face, for holding a clamping insert which is formed from a base leg and two fastening legs projecting from the base leg. On each of the opposite longitudinal sides of the step head there is formed a threaded bore for receiving a fastening screw whose screw head is received in a through-opening which is formed in the fastening leg of the clamping insert that is assigned to the longitudinal side, wherein, on each side, the longitudinal axes of the threaded bore and of the through-opening assigned thereto have an offset when the base leg bears against the end face. Also, a chuck has a chuck body, in which such clamping jaws are arranged in uniformly-distributed radial jaw guides.

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: Methacrolein is prepared in a continuous process by a Mannich condensation reaction of formaldehyde with propanal. A methacrolein polymerization inhibitor is introduced during the production process and a part thereof is recycled back into the reactor where the Mannich condensation reaction is carried out.

Abstract: A process can be used for producing methacrylic acid or a methacrylic acid ester. The process involves producing acrolein, reacting the produced acrolein with hydrogen to produce propanal, reacting the propanal with formaldehyde to produce methacrolein, and oxidizing the methacrolein in the presence of an oxygen containing gas and optionally an alcohol, to obtain methacrylic acid or methacrylic acid ester.

Abstract: A process can be used for manufacturing an acrylic copolymer having increased heat resistance, high transparency, and improved adhesion to metal surfaces. The process involves polymerizing a monomer mixture, optional heating of the copolymer mixture, and removing volatile components from the copolymer mixture by degassing. Moulding compositions containing this copolymer are highly suitable for manufacturing optical elements for optoelectronic devices containing acrylic and metallic or ceramic parts.

Abstract: A continuous process can be used for preparing methacrylic acid by catalytic hydrolysis of methyl methacrylate that has been prepared proceeding from C-2, C-3, or C-4 raw materials. In this process, methyl methacrylate of high purity is reacted with water in the presence of a Brønsted catalyst to give a reaction mixture containing the reactants and products and worked up in a distillation column. In the distillation column, a condensate containing an azeotrope of MMA with methanol is produced at the top, a vapour condensate containing methacrylic acid of high purity is produced in the middle part of the column, and a substance mixture containing high-boiling by-products and a small amount of methacrylic acid is obtained in the bottom of the column.

Abstract: An extruded foil may include at least one layer in which platelet-shaped filler particles are uniformly distributed in a polymer matrix comprising at least one fluoropolymer and at least one further layer. The foil may have a particularly high TSR, a high weathering resistance, and excellent mechanical properties. Therefore, the foil may be highly suitable for surface-protection of materials such as polyvinyl chloride (PVC) and for use in high-pressure laminates (HPLs).

Abstract: A device can be used for the degassing of a two-component multiphase polymer-monomer material. A corresponding degassing extruder contains the degassing device. The device for degassing contains at least one nozzle part having a convergent geometry, at least one constant part, and at least one diffusor part having a divergent geometry. The diffusor part contains at least three zones each having a divergent geometry, and the opening angles of the zones are specifically adapted in order to improve the separation of components of the polymer material. A process for degassing a polymer material uses the degassing device.

Abstract: An improved process for synthesizing methacrylic acid and/or alkyl methacrylates, in particular methyl methacrylate (MMA), involves reacting acetone and hydrogen cyanide in the presence of an alkaline catalyst in a first reaction stage such that a first reaction mixture containing acetone cyanohydrin (ACH) is obtained. The process then involves working up the first reaction mixture containing acetone cyanohydrin (ACH), reacting acetone cyanohydrin (ACH) and sulfuric acid in a second reaction stage (amidation), and heating the second reaction mixture in a third reaction stage (conversion), such that methacrylamide (MAA) is obtained. The process further involves hydrolyzing or esterifying methacrylamide (MAA) with water and, optionally, alcohol, preferably water and optionally methanol, in a fourth reaction stage such that methacrylic acid or alkyl methacrylate is formed. The sulfuric acid used has a concentration of 98.0 wt % to 100.0 wt %.

Abstract: A process for producing methacrylic acid or a methacrylic acid ester including, producing acrolein, reacting the produced acrolein with hydrogen to produce propanal, reacting the propanal with formaldehyde to produce methacrolein, and oxidizing the methacrolein in the presence of an oxygen containing gas and optionally an alcohol, to methacrylic acid or a methacrylic acid ester.

Abstract: A novel process can be used for a heterogeneously catalysed oxidation reaction, in the presence of a pulverulent noble metal-containing catalyst, where (meth)acrolein, an alkyl alcohol, in particular methanol, and an oxygen-containing gas are converted to an alkyl (meth)acrylate, in particular methyl (meth)acrylate. A corresponding reactor suitable for performing the reaction is also useful. The process allows for an effective retention of the particulate catalyst and the continuous discharge of fines fractions of the catalyst powder which are present, particularly in a fresh catalyst batch as a consequence of its preparation. Such fines fractions may also be produced by abrasion during the reaction. The process allows for effective recycling, recovery, and utilization of these discharged catalyst fractions.

Abstract: An improved process for synthesizing alkyl methacrylates, in particular methyl methacrylate (MMA), involves reacting acetone cyanohydrin (ACH) and sulfuric acid in a first reaction stage (amidation). The process then involves heating the first reaction mixture in a second reaction stage (conversion) such that methacrylamide (MAA) is obtained; and then esterifying methacrylamide (MAA) with alcohol and water, preferably methanol and water, in a third reaction stage such that alkyl methacrylate is formed. The sulfuric acid used has a concentration of 98.0 wt % to 100.0 wt %. A subsequent working up of the third reaction mixture involves least two distillations in which the byproducts methacrylonitrile (MeAN) and acetone are obtained as an aqueous heteroazeotrope at least in part in the top fraction. At least some of the aqueous heteroazeotrope is removed from the process and at least partially reintroduced into the third reaction stage.

Abstract: A process for preparing methyl methacrylate (MMA) and/or methacrylic acid (MAS) having improved yield, involves amidation, conversion, and hydrolysis/esterification. Especially high yields are obtained during the amidation and in the subsequent so-called conversion.