摘要:
Catalytic procedure for the preparation of an organic carbonate having general formula (I): ##STR1## wherein R represents a C.sub.1 -C.sub.10 alkyl radical, linear or branched, or a C.sub.5 -C.sub.8 cycloalkyl radical; or of a cyclic organic carbonate having general formula (II): ##STR2## wherein R' represents a C.sub.2 -C.sub.5 alkylene radical, linear or branched; including the reacting of an aliphatic or cyclo-aliphatic alcohol having general formula (III):R--OH (III)or an aliphatic diol having general formula (IV):HO--R'--OH (IV)wherein R and R' have the meaning described above, with carbon monoxide and oxygen, in the presence of a catalyst composed of a cobalt(II) or cobalt(III) ion and an organic binder containing at least one oxygen atom, characterized in that the process is carried out in the presence of at least one reaction coadjuvant selected from the following groups of linear or cyclic compounds: ureas, nitriles, amides, phosphoramides, sulphones, sulphoxides, carbamates.
摘要:
A liquid composition which can undergo radical polymerization to produce an almost colorless and easily dyeable organic glass, containing (i) at least one poly(allyl carbonate) of a polyhydroxy alcohol having from 2 to 20 carbon atoms and from 2 to 6 hydroxy groups in the molecule, and (ii) at least one aliphatic polyol having from 2 to 5 hydroxy groups in the molecule, in quantities from 0.01 to 1% by weight on the whole composition.
摘要:
A continuous process is described for preparing a di-alkyl carbonate, e.g. dimethylcarbonate, via oxidative carbonylation of the corresponding alkanol, e.g. methanol, in the presence of a catalyst system containing a copper alkoxy-halide and water with a mole ratio of the water to the copper salt of between 0.25 and 2.0 and preferably between 0.5 and 1. In this manner extremely high di-alkyl carbonate formation rates are obtained.
摘要:
Organic glasses and surface coatings are prepared, with short hardening cycles, by submitting to the action of U.V. light a liquid polymerizable composition containing at least one di-(allyl carbonate) or poly(allyl carbonate) of a diol or polyol, a photoinitiator and a vinyl ester monomer and/or an organic peroxide.The composition can additionally contain small amounts of an organic compound selected from among those compounds which are used in the art in order to stabilize the organic polymers to the degrading action of U.V. light.The composition is preferably heated before being treated with U.V. light.
摘要:
A liqid composition polymerizable under the influence of free-radical initiators to yield crosslinked polymers useful as organic glasses endowed with high abrasion strength, contains an oligomer allyl-carbonate with two end allyl groups, a monomer allyl-carbonate with at least four end allyl groups and possibly also one or more reactive diluents containing groups of allyl, vinyl or methacryl type.
摘要:
Process for the production of alkyl isocyanates which can be defined by the general formula: R--N.dbd.C.dbd.O wherein R is an alkyl radical having from 1 to 4 carbon atoms by thermal decomposition of phenyl-N-alkyl urethans which can be defined by the general formula: ##STR1## wherein R has the above defined meaning. Said thermal decomposition is carried out without any substance having a catalytic activity being present in the decomposition reaction, by heating to a temperature of from 180.degree. C. to 210.degree. C. under the atmospherical pressure or a slightly reduced pressure, a mixture of phenol and phenyl-N-alkyl urethan, in a molar ratio of the former to the latter equal to or nearly equal to 1:1, removing by vaporization the phenol and the alkyl isocyanate from said vaporized products and maintaining in the reaction mixture, substantially throughout the thermal decomposition a molar ratio of phenol to phenyl-N-alkyl urethan not lower than about 1:1.
摘要翻译:制备烷基异氰酸酯的方法,其可以由通式RN = C = O定义,其中R是通过苯基-N-烷基氨基甲酸酯的热分解具有1至4个碳原子的烷基,其可以由 通式:其中R具有上述定义的含义。 所述热分解在没有任何具有催化活性的物质在分解反应中进行,通过在大气压或稍微减压下加热至180℃至210℃的温度,苯酚 和苯基-N-烷基氨基甲酸酯以前者与后者的摩尔比等于或几乎等于1:1,通过蒸发从所述汽化产物中蒸发苯酚和异氰酸烷基酯并基本上保持在反应混合物中 苯酚与N-烷基氨基甲酸酯的摩尔比热分解不低于约1:1。
摘要:
A process is described for the preparation of phenol by the hydrodeoxygenation of polyhydroxylated benzene derivatives or by the selective hydroxylation of benzene under depletive conditions, characterized in that the above-mentioned reactions are carried out in the presence of a catalyst based on multi component metal oxides comprising at least one metal selected from the groups VB, VIB, VIII, IB, IIB, IVA, VA.
摘要:
The invention relates to a new process which allows the preparation of TS-1 zeolites in a pure phase and with a crystallinity higher than 95%, operating at reduced reaction volumes, and obtaining high productivities and extremely high crystallization yields. The particular crystalline form of the TS-1 zeolite thus prepared, is also described.
摘要:
The invention relates to a multi-step chemical transformation process for the production of 2,6-dimethylnaphthalene starting from one or more naphthalene hydrocarbons or hydrocarbon blends containing the same, one or more benzene hydrocarbons and, optionally, a methylating agent reacted in the presence of a catalyst containing a zeolite belonging to the MTW structural group, where hydrogen is fed in at least one of the steps.
摘要:
The invention relates to the use of dialkyl carbonates as solvents for expanded polystyrene and to a new process for the recycling of expanded polystyrene. Said process comprises the volume reduction of expanded polystyrene by dissolution with a dialkyl carbonate, or a blend of dialkyl carbonates, the removal of the insoluble components by filtration, the selective precipitation of polystyrene with a non-solvent or a blend of non-solvents, the separation, drying and extrusion of the precipitated polystyrene. This process allows the recovery of pure polystyrene without altering its properties.