摘要:
Disclosed is a component for a catalyst for the polymerization of alpha-olefins to stereoregular polymers having narrow molecular weight distribution. The product is formed by the reaction of a solid catalyst-forming component comprising (1) a Ti compound having at least one Ti-halogen bond and (2) optionally, an electron-donor compound, supported on an anhydrous Mg dihalide in active form, with certain amounts of an organic compound (AH) containing at least one active hydrogen atom, in the presence of a liquid medium which is inert with respect to the Ti compound and the other components of the catalyst component, and which has a dielectric constant greater than 2 at 20.degree. C.Catalysts comprising the reaction product of the solid catalyst component prepared as above described, with an Al-alkyl compound and an electron-donor compound are also disclosed.
摘要:
A process for preparing hyperpure propylene (co)polymers comprising polymerizing the monomer(s) in liquid monomer in the presence of a catalyst obtained by reacting an Al-trialkyl compound with a solid catalyst component comprising magnesium dihalide in active form, having supported thereon a titanium chloride or chloroalcoholate, and an ether having the general formula: ##STR1## where R and R" are the same or different and are C.sub.2-18 alkyl, C.sub.3-18 cycloalkyl, C.sub.6-18 aryl, C.sub.7-18 arylalkyl or alkylaryl radicals.
摘要:
Catalysts for polymerizing ethylene to high yields of polyethylene having a controlled particle size are disclosed. The catalysts are prepared from new catalyst-forming components which are the reaction products of solid halogenated titanium compounds, Grignard compounds and halogenating agents. Said components, on mixing with organometallic compounds of metals belonging to Groups I-III of the Mendelyeev Periodic Table result in the catalysts capable of polymerizing ethylene to polyethylene having a controlled particle size.
摘要:
Cyclopolyenic 1,3-diethers wherein the carbon atom in position 2 belongs to a particular cyclic or polycyclic structure containing two or three unsaturations, solid catalyst components and catalysts therefrom, the catalysts comprising the reaction product of: i. a solid catalyst component containing an internal donor; ii. an Al-alkyl compound, and optionally iii. an external donor; the internal donor and/or the external donor being cyclopolyenic 1,3-diethers. The catalysts are useful for the polymerization of alpha-olefins.
摘要:
Process for the preparation of a solid catalyst component for olefins polymerization including (1) a magnesium halide in active form, (2) a titanium compound, and (3) an electron-donor compound selected from particular 1,3-diethers, the process being carried out by reaction between the compounds from (1) to (3), and including at least two additions of electron-donor (3) in the following order: a) one addition prior to or during a reaction with the titanium compound or with a halogenated compound, and then b) one addition prior to or during a further reaction with the titanium compound.
摘要:
Cyclopolyenic 1,3-diethers wherein the carbon atom in position 2 belongs to a particular cyclic or polycyclic structure containing two or three unsaturations, solid catalyst components and catalysts therefrom, the catalysts comprising the reaction product of: i. a solid catalyst component containing an internal donor; ii. an Al-alkyl compound, and optionally iii. an external donor; the internal donor and/or the external donor being cyclopolyenic 1,3-diethers. The catalysts are useful for the polymerization of alpha-olefins.
摘要:
Disclosed are reverse osmosis anisotropic gel-type membranes having the structure: ##STR1## WHEREIN N IS A WHOLE NUMBER; A is a divalent group derived from piperazine and having the structure: ##STR2## WHEREIN X IS 0 TO 8 AND R is an alkyl group, and Q is at least two divalent organic groups selected from the group consisting of: ##STR3## wherein Y is O or S, ##STR4## Also disclosed are processes for preparing such membranes.
摘要:
A process for the preparation of heterophasic elastomeric polymer comprising the step of polymerizing ethylene, an alpha-olefin CH2=CHL, where L is an alkyl, cycloalkyl or aryl radical with 1-10 carbon atoms and a non-conjugated diene in the presence of a catalyst system comprising a transition metal catalyst component supported on a porous alpha-olefin polymer, characterized in that at least part of the diene is impregnated on the porous alpha-olefin polymer.
摘要:
Catalyst system for the polymerization of olefins CH2═CHR, wherein R is hydrogen or a hydrocarbon radical having 1-12 carbon atoms, comprising the product of the reaction between (a) a solid catalyst component comprising Mg, Ti, and halogen, (b) dimethylaluminium chloride (DMAC) and (c) an alkylaluinium compound, in which the molar ratio between (b) and (c) is lower than 10. This kind of catalyst system is particularly suitable for the preparation of copolymers of ethylene with &agr;-olefins due to its high capacity for incorporating the comonomer while at the same time maintaining high yields.
摘要:
A debris shedding buoy having a float body with a top and a bottom is provided. The buoy includes a slide rail, adapted for slidable engagement to a mooring line, is attached to the bottom of the float body. The slide rail is located in a generally centered position beneath the float body and is oriented in a first direction. A rudder device is affixed to the float body and adapted to produce a stabilizing force to maintain the float body in a quasi stable orientation with respect to a current direction, with the first direction being generally aligned to the current direction. Debris lodging against the float body overcomes the stabilizing force produced by the rudder device, causing the float body to rotate from the quasi stable orientation to a second orientation to shed the debris whereupon the float body rotates back to the quasi stable orientation.