摘要:
Titanium or vanadium zeolites are pretreated by contacting with an amino polyacid compound, such as ethylenediaminetetraacetic acid or a salt thereof, prior to use in olefin epoxidation with hydrogen peroxide.
摘要:
A multi-step process for producing DNT employing a mononitration step in a single liquid phase at an elevated temperature using a carefully controlled amount of water, followed by a phase separation step prior to dinitration of the MNT present in the resulting organic phase. This process results in a DNT product with a desired isomer ratio of 2,4-DNT to 2,6-DNT and provide relatively fast nitration rates with less by-products.
摘要:
A process for increasing the rate of catalytic hydrogenation of aromatic amines by reacting aromatic amines with hydrogen in the presence of a noble metal catalyst, a water miscible organic solvent, lithium hydroxide catalyst promoter, and water in an effective amount to increase the rate of the hydrogenation reaction without an appreciable increase in total amounts of by-products.
摘要:
A process for increasing the rate of catalytic hydrogenation of aromatic amines by reacting aromatic amines with hydrogen in the presence of a noble metal catalyst, an organic solvent or a mixture of solvents, and at least one salt of a transition or lanthanide metal as a promoter, in an effective amount to increase the rate of the hydrogenation reaction, decrease the induction period, and decrease the amount of higher boiler by-products.
摘要:
Aniline and formaldehyde are condensed (2-10 moles aniline per mole of formaldehyde) at ambient temperature in the absence of acid catalysts to give a mixture of aminals (anilinoacetals) and aniline from which the water is removed. The anhydrous aminals are contacted with a solid catalyst (clays, zeolites, diatomaceous earth) using either batch or continuous operation initially at 20.degree. C to 55.degree. C until benzylamine formation is substantially complete, then at 50.degree. C to 65.degree. C until benzylamine conversion to methylene polyphenyl polyamines is 75 - 90% complete and finally at 80.degree. C to 100.degree. C. A polyamine mixture is obtained in which diaminodiphenylmethane is the major (order of 90 percent by weight or higher) component, the bulk of the higher oligomeric polyamines being triamine. The diaminodiphenylmethane component contains of the order of 85 percent of 4,4'-isomer, the rest being 2,4'-isomer except for very small amounts (order of 2 percent or less) of 2,2'-isomer.Advantages of the process include high yield of diaminodiphenylmethane with relatively high 4,4'-isomer content, low oligomeric polyamine content, low temperature operation (energy consumption lower), no acidic reactants to cause corrosion of equipment, and rapid rates of conversion.
摘要:
The invention is a catalyst comprising a titanium or vanadium zeolite, a binder, and zinc oxide, wherein the catalyst is preparing an aqueous mixture of the zeolite, a binder source, and a zinc oxide source, and subjecting the mixture to rapid drying. The catalyst is useful in olefin epoxidation.
摘要:
Allyl carbamates are disclosed. The allyl carbamates are prepared by reacting an isocyanate with an allylic alcohol or alkoxylated allylic alcohol. Suitable isocyanates are selected from hexamethylene diisocyanate (HDI), HDI biuret, dimer, HDI trimer, HDI allophanate, isophorone diisocyanate (IPDI), IPDI trimer, IPDI allophanate, bis(isocyanatocyclohexyl)methane, and mixtures thereof. The allyl carbamates have at least two allyl functional groups per molecule. UV-curable and air-drying coatings formulated from the allyl carbamates show excellent chemical resistance and physical properties.
摘要:
Allyl carbamates are disclosed. The allyl carbamates are prepared by reacting an isocyanate with an allylic alcohol or alkoxylated allylic alcohol. Suitable isocyanates are selected from hexamethylene diisocyanate (HDI), HDI biuret, dimer, HDI trimer, HDI allophanate, isophorone diisocyanate (IPDI), IPDI trimer, IPDI allophanate, bis(isocyanatocyclohexyl)methane, and mixtures thereof. The allyl carbamates have at least two allyl functional groups per molecule. UV-curable and air-drying coatings formulated from the allyl carbamates show excellent chemical resistance and physical properties.
摘要:
A process is described for the preparation of polymethylene polyphenyl polyamines containing from 40 to 60 percent by weight of diamine and also containing markedly less high molecular weight polyamines than products hitherto available. Phosgenation of the polyamines gives the corresponding mixture of polymethylene polyphenyl polyisocyanates of markedly lower viscosity and lighter color than products hitherto available, and yielding polymer foams which are substantially white in color.The process comprises condensing aniline and formaldehyde (molar ratio 4-10:1) in the absence of catalyst, separating water from the resulting aminal mixture, contacting the aminals at 20.degree. C to 60.degree. C with a solid catalyst (diatomaceous earths, clays, zeolites) until formation of benzylamines is substantially complete, distilling aniline from the resulting benzylamines under reduced pressure and below 150.degree. C until the aniline content is 3 to 22 percent by weight, and contacting the resulting product with a solid catalyst (diatomaceous earths, clays, zeolites) at 100.degree. C to 190.degree. C until conversion to polymethylene polyphenyl polyamines is complete.
摘要:
Disclosed are new coatings compositions based on an HDI isocyanurate or biuret polyisocyanate and a bis(imine) reaction product of a diaminoalkane containing between two and five carbon atoms with an alkyl aldehyde containing between four and seven carbon atoms (advantageously a bis(imine) product of the reaction of 1,4-diaminobutane and isobutyraldehyde). The latter bis(imine) is completely miscible in HDI isocyanurate and biuret polyisocyanates, and, as a reactive diluent, allows the preparation of high performance coatings formulations that require only small amounts of solvents to achieve a conveniently sprayable viscosity.