摘要:
Disclosed is a method for epoxidizing olefins, which enables an epoxy compound containing no halogen atom with high yield. Specifically disclosed is an oxidizing agent composition for epoxidation of olefins, which is characterized by containing peroxide which exhibits basicity when dissolved in water and an acid anhydride.
摘要:
The invention relates to prepolymers for native epoxide resins that can be used on an industrial scale or in the various areas of everyday life, e.g. as coating materials or adhesives. The invention also relates to a method for producing these prepolymers. The aim of the invention is to provide substances that are suitable as prepolymers, that are suitable for obtaining native epoxide resins and that can be produced without safety hazards at economical costs. According to the invention, polyhydroxy-polyepoxy fatty acid alkyl ester ethers are used as the prepolymers. They belong to a class of substances that comprises oxirane rings, ether compounds and OH groups, and that therefore correspond to the synthetic resin components to a high degree. According to the inventive method, fatty alkylesters are epoxidized with hydrogen peroxide under the influence of performic acid at a temperature of from 70 °C to 90 °C. A part of the epoxides produced immediately reacts to polyhydroxyethers. The product mixtures so produced are removed from the acid water at a temperature of approximately 65 °C using fine-meshed wire nettings. The remainder of the acid water is removed by vacuum evaporation.
摘要:
Au cours d'un procédé à plusieurs étapes d'époxydation continue de doubles liaisons d'oléfines situées centralement ou en bout de chaîne, comportant plus de 12 atomes de C, des acides gras non saturés et leurs esters, ainsi que des alcools non saturés dont le radical alcoyle comporte de 8 à 18, de préférence 18, atomes de C, et des triglycérides, de préférence de l'huile de soya, avec utilisation d'acide performique formé in situ à partir du peroxyde d'hydrogène et de l'acide formique, on amène les réactants, oléfine et peroxyde d'hydrogène/acide formique, à une réaction en cascade composée d'au moins 3 étapes à pression atmosphérique dans un contre-courant en croix. La phase oléfinique est ainsi placée dans la première étape de réaction, le peroxyde d'hydrogène et l'acide formique sont ajoutés en écoulements séparés à l'avant dernière étape de réaction et les phases oléfine et peroxyde d'hydrogène/acide formique (phase eau acidulée) sont séparées l'une de l'autre après chaque étape de réaction dans un séparateur de phases. La phase contenant l'oléfine passe successivement par les étapes de réaction I à n, alors que l'eau acidulée après l'étape de réaction (n - 1) passe par les étapes de réaction (n - 2) à II en sens inverse de la phase oléfine, et finalement par les étapes n et I; la température de réaction se situe entre 50 et 80oC dans les réacteurs, mais entre 15 et 60oC dans les séparateurs de phases.
摘要:
Dental composition comprising (a) one or more di- or polyepoxides having 2 to 5 epoxide groups and having a molecular weight of from 200 to 700 Da, or a macromonomeric reaction product obtainable by reacting the diepoxide with a dicarboxylic acid in a molar ratio [diepoxide]/[dicarboxylic acid] of at least 2; (b) one or more primary monoamines and/or disecondary diamines; (c) optionally one or more aliphatic polyamines; (d) a particulate filler, wherein the molar ratio of epoxide groups in component (a) to the N-H bonds in component (b) and (c) [epoxide (a) ]/[N-H (b),(c) ] is in the range of from 0.9 to 1.1; wherein the di- or polyepoxide having 2 to 5 epoxide groups is a compound of the following formula (I): €ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ A(BZ m ) n €ƒ€ƒ€ƒ€ƒ€ƒ(I) wherein A represents an n-valent organic moiety optionally having 1 to 10 heteroatoms selected from oxygen atoms and sulfur atoms; and B represents an m+1-valent organic moiety, Z is an epoxide group which may have a substituent, m which are independent from each other represent an integer of at least 1; and n is an integer of from 1 to 5; wherein the m are selected so that 2 to 5 epoxide groups are present; wherein the composition does not contain any 2,2-bis-(4-hydroxyphenyl)-propane, or 2,2-bis-(4-hydroxyphenyl)-methane.
摘要:
The novel method enables oxidation of organic compounds with peroxycarboxylic acids which are produced in situ in the presence of enzymes by reacting hydrogen peroxide with saturated aliphatic carboxylic acid esters and/or mixtures of corresponding carboxylic acids and alcohol, whereby short-chained carboxylic acids and long-chained alcohol are used and the water which is produced and/or added during the reaction is fully or partially removed.
摘要:
A process is disclosed for preparing epoxide group-containing organic compounds. Monounsaturated or polyunsaturated organic compounds are oxidised with an aqueous hydrogen peroxide solution in the presence of carboxylic acids. The process is characterised in that 0.01 to 0.5 % by weight of an anti-oxidising agent, with respect to the amount of unsaturated compounds, is added to the reaction mixture, and in that inert gas is made to flow during the reaction through the reaction vessel. This process is easy to implement and produces high yields of epoxide group-containing organic compounds.
摘要:
To reduce formation of side products and to enhance a selectivity rate in a method for producing 3-chloro-2-hydroxypropyl (meth)acrylate and in a method for producing glycidyl (meth)acrylate. The present invention is characterized by a method for producing 3-chloro-2-hydroxypropyl (meth)acrylate through a reaction of (meth)acrylic acid and epichlorohydrin; more specifically, the reaction is carried out by using 0.5 to 2 mol of epichlorohydrin relative to 1 mol of (meth)acrylic acid, and by adding epichlorohydrin to (meth)acrylic acid in the presence of a catalyst. Also, the present invention is characterized by a method for producing glycidyl (meth)acrylate through a reaction of 3-chloro-2-hydroxypropyl (meth)acrylate and a basic carbonate compound in a polar solvent.
摘要:
A process for producing cumene, characterized in that a copper catalyst precursor containing copper in an oxidized state is reduced with hydrogen in liquid cumene to prepare a copper catalyst and cumyl alcohol is subjected to hydrogenolysis in the presence of the copper catalyst; and a process for producing propylene oxide which includes that process.