摘要:
A metallocene compound of a metal M of group 4 in the table of elements, comprising a cyclopentadienyl group and at least one oligomeric group R' bonded to M, having the following formula (II):-(A x D y U z ) R I wherein: A represents any monomeric unit deriving from a vinylaromatic group polymerizable by means of anionic polymerization, having from 6 to 20 carbon atoms; D represents any monomeric unit deriving from a conjugated diolefin polymerizable by means of anionic polymerization, having from 4 to 20 carbon atoms; U represents any generic optional monomeric unit deriving from an unsaturated compound copolymerizable with any of the above conjugated diolefins D or vinylaromatic compounds A; RI represents hydrogen or a hydrocarbyl group having from 1 to 20 carbon atoms, each index "x" and "y" can be independently zero or an integer, provided the sum (x+y) is equal to or higher than 2, preferably between 2 and 50, more preferably between 2 and 25; "z" can be zero or an integer ranging from 1 to 20. Said complex can be used for the formation of catalytic systems, in particular for the (co)polymerization of olefins, with enhanced stability and a high activity, so as to enable transportation and storage for prolonged periods of time.
摘要翻译:包含环戊二烯基和与M键合的至少一个低聚基团R'的元素表中第4族金属M的金属茂化合物,其具有下式(II): - (A x D y U z)R 1其中:A 表示任何衍生自可通过阴离子聚合可聚合的乙烯基芳族基团的单体单元,具有6-20个碳原子; D表示衍生自可通过阴离子聚合进行聚合的共轭二烯烃的任何单体单元,具有4至20个碳原子; U表示衍生自可与任何上述共轭二烯烃D或乙烯基芳族化合物A共聚的不饱和化合物的任何通用任选单体单元; RI表示氢或具有1至20个碳原子的烃基,每个指数“x”和“y”可以独立地为零或整数,条件是总和(x + y)等于或大于2,优选为 2和50,更优选2和25之间; “z”可以是零或1-20的整数。所述配合物可以用于形成催化体系,特别是用于烯烃(共)聚合的催化体系,其具有增强的稳定性和高活性,从而能够 运输和储存很长一段时间。
摘要:
A process is described for the hydrogenation of olefin double bonds present in polymers and copolymers of conjugated dienes, which comprises putting the above polymer or copolymer of conjugated dienes in contact with hydrogen in an inert solvent, in the presence of a catalytic system, characterized in that the above catalytic system essentially consists of one or more titanium compounds selected from those having general formula (I) wherein: M is selected from Ti(III) and Ti(IV) and their mixtures.
摘要:
The present invention concerns a process for preparing 2,6-dimethylnaphthalene which comprises subjecting 1,6 and/or 1,5-dimethylnaphthalene, optionally mixed with other isomers of dimethylnaphthalene, to isomerization, which comprises treating said compounds at a temperature ranging from 100 to 400°C, under at least partially liquid phase conditions, in the presence of an MTW zeolite.
摘要:
Titanium complex having general formula (I) (RCOO)nTiXp wherein R is a monofunctional hydrocarbyl radical having from 1 to 20 carbon atoms and a number of halogen atoms, selected from fluorine, chlorine and bromine, preferably chlorine, ranging from 1 to 6; X is chlorine, bromine or a beta-dicarbonyl group such as acetylacetone (AcAc), formylacetone, benzoylacetone, dibenzoylmethane; p + n = 2, 3, 4, preferably p + n = 3; n is greater than or equal to 1. The preparation of the above complex and its use in the co- and ter-polymerization of α-olefins, are also described.
摘要:
A process is described for the preparation of a heterogeneous catalyst containing rhenium as active component and an inert carrier, characterized in that said inert carrier is previously subjected to thermal treatment before the supporting of the active component and the activation of the heterogeneous catalyst is effected by means of thermal treatment followed by a rapid final cooling. The catalyst is particularly active in the metathesis reaction of olefins.
摘要:
Allyl polyalkylcyclopentadienyl complex of a metal of group 4 of the periodic table, and its use in the preparation of a catalytic composition for the (co)polymerization of α-olefins. said complex is advantageously stable in solution and rapidly forms catalytic compositions with a high activity without the necessity of effecting alkylating pretreatment.
摘要:
The present invention relates to a process for the preparation of zeolitic catalysts of the MFI type in spheroidal form. The process consists in emulsifying and consolidating in paraffinic hydrocarbons, in the presence of a non-ionic surface-active agent or a suitable combination of a non-ionic surface-active agent and a cationic surface-active agent, a dispersion of particles of zeolitic material of the MFI type in a silica sol.