523 results about "Aluminum alkyl" patented technology

The invention discloses a loading non-metallocene single active central catalyst composition which is obtained through adopting an alkyl aluminoxane / magnesium chloride / silica gel carrier as a carrier and loading a non-metallocene single active central transition metal composition and a preparation method thereof. The catalyst system consisting of the catalyst composition catalyzes ethylene to polymerize or copolymerize and has high polymerization activity. The carrier is simple to prepare; the prepared loading catalyst granule has good shape and adjustable size; and the obtained polythene powdery material has high stacking density.

The present invention is directed to the use of aluminum alkyl activators and co-catalysts to improve the performance of chromium-based catalysts. The aluminum alkyls allow for the variable control of polymer molecular weight, control of side branching while possessing desirable productivities, and may be applied to the catalyst directly or separately to the reactor. Adding the alkyl aluminum compound directly to the reactor (in-situ) eliminates induction times.

A process for producing an olefin polymer, which comprises contacting at least two olefin monomers under polymerization conditions with a catalyst composition comprising A) an aluminoxane-impregnated support prepared by contacting an aluminoxane with an inert carrier material and heating to a temperature of at least about 80 DEG C.; B) a metallocene of the formula: (L)y(L')MY(x-y-1) wherein M is a metal from groups IIIB to VIII of the Periodic Table; each L and L' is independently a cycloalkadienyl group bonded to M; each Y is independently hydrogen, an aryl, alkyl, alkenyl, alkylaryl, or arylalkyl radical having 1-20 carbon atoms, a hydrocarboxy radical having from 1-20 carbon atoms, a halogen, RCO2-, or R2N-, wherein R is a hydrocarbyl group containing 1 to about 20 carbon atoms; y is 0, 1, or 2; x is 1, 2, 3, or 4; and x-y> / =1; C) a bulky aluminum alkyl of the formula: AlR1xR2(3-x) wherein R1 is a hydrocarbyl group having 1 to 12 carbon atoms; x is an integer from 0 to 2; R2 is a hydrocarbyl group of the formula -(CH2)y- R3, wherein y is an integer from 1 to 8; and R3 is a saturated or unsaturated hydrocarbyl group having 3 to 12 carbon atoms containing at least one ring, and D) methylaluminoxane is provided. The catalyst composition may be used to prepare olefin polymers having increased short chain branching frequency.

The present invention discloses catalyst for high temperature olefin polymerization and its preparation process and use. The catalyst includes: supported Ziegler-Natta catalyst of titanium halide compound and organic electron donor compound supported with MgCl2 alcoholate carrier; aluminoxane prepared with trialkyl aluminum and water; and one kind of organic electron donor, such as organosilicon compound R2Si(OCH3)2, where R is phenyl, isopropyl, isobutyl or cyclopentyl. The said catalyst can catalyze propylene polymerizing reaction at 50-120 deg.c in excellent catalytic activity, and the prepared polymer has isotactivity index of 85-99 %, number average molecular weight of 43000-104000 g / mol, molecular weight distribution index of 4.5-10.6.

Disclosed herein is a polyolefin polymer having improved properties wherein the polymer is produced using a chromium based catalyst in combination with aluminum alkyl activators and co-catalysts. Also disclosed is a pipe comprising the inventive polymer and a film comprising the inventive polymer, each having improved properties over those known in the art.

The invention relates to the field of olefin polymerization, and particularly provides polypropylene, a preparation method and applications thereof, wherein the polypropylene has a melt flow index MFRof more than 30 g / 10 min, has an isotactic index of 96-99.5 wt%, and has a molecular weight distribution index MW / Mn of 3-5.5. The preparation method comprises: polymerizing propylene in the presenceof a catalyst under an olefin polymerization condition to obtain a polypropylene product, wherein the catalyst contains a catalyst component, an alkyl aluminum compound, and optionally an external electron donor, the catalyst component contains the product obtained by carrying out a reaction on a magnesium source, a titanium source and an internal electron donor, the internal electron donor contains a phosphate compound and a diether compound, and the phosphorus content (calculated as the phosphorus element) in the catalyst component is not more than 0.06 wt%. According to the present invention, the polypropylene integrates characteristics of high isotactic index, high melt flow index and narrow molecular weight distribution.

The invention describes a catalytic composition obtained by interaction of an alkyl titanate on the one hand with a preformed mixture of an alkylaluminium and a Lewis base on the other hand. The invention also describes the use of said composition in a process for the selective dimerization of ethylene to 1-butene.

The invention relates to the field of olefin polymerization, and discloses a catalyst system. The catalyst system comprises a titaniferous solid catalyst component, an aluminum alkyl compound and an external electron donor compound, wherein the titaniferous solid catalyst component contains at least two internal electron donor compounds of a polytrimethylene terephthalate type compound and a diether type compound, and the external electron donor compound is an ether base ester compound or a combination of the ether base ester compound and hydroxyl silane dialkyl oxygen radicals. The invention further provides application of the catalyst in olefin polymerization reaction. According to the catalyst system and the application of the catalyst in the olefin polymerization reaction, by adding the ether base ester compound or the combination of the ether base ester compound and the hydroxyl silane dialkyl oxygen radicals as the external electron donors to be used in the olefin polymerization reaction when the solid catalyst component with the polytrimethylene terephthalate type compound and the diether type compound being the internal electron donors is subjected to the olefin polymerization reaction, not only can the catalyst maintain high activity, but also sensibility of hydrogen regulation of the catalyst can be improved.

The present invention relates to a nitrogen heterocyclic carbene rare earth complex, a catalyst system which consists of the present invention, aluminum alkyl and an organoboron salt can catalyse the isoprene to carry out the solution polymerization, so as to prepare the polyisoprene with the crystallization property, high 3, 4-structure and high glass transition temperature (Tg). The molar ratio of aluminum alkyl and the rare earth complex is within the scope of 1 to 100, the molar ratio of the organoboron salt and the rare earth complex is within the scope of 0.5 to 2.0; the solvent which is used for polymerization can be toluene, bromobenzene, n-hexane, dichloromethane or chlorobenzene; the polymerization temperature range is -20 DEG C to 80 DEG C, the reaction time of polymerization at minus 20 DEG C is 36 hours, the reaction time of polymerization at 80 DEG C is 1 hour, and the monomer conversion rate can be up to 100 percent. The reaction is characterized by active polymerization, the molecular weight of the product can be controlled by the molar ratio of the monomer and the catalyst, the molecular weight of the polyisoprene can achieve 360,000 at most, and the glass transition temperature Tg is equal to 5 DEG C to 50 DEG C. The content of the 3, 4 structure of the polyisoprene is affected by the spatial effect and the electronic effect of the rare earth complex, the solvent type for polymerization reaction and the polymerization reaction temperature and so on, which is changed between 76 percent and 99 percent.

A polymethylaluminoxane preparation exhibiting excellent storage stability with a high yield is provided. A polymethylaluminoxane preparation is formed by thermal decomposition of an alkylaluminum compound having an aluminum-oxygen-carbon bond, the alkylaluminum compound being formed by a reaction between trimethylaluminum and an oxygen-containing organic compound. In this preparation,(i) the oxygen-containing organic compound reacting with trimethylaluminum is an aliphatic or aromatic carboxylic acid represented by the general formula (I),R1—(COOH)n  (I),wherein R1 represents a hydrocarbon group of C1-C20 straight or branched alkyl groups, alkenyl groups or aryl groups, and n represents an integer of 1 to 5;(ii) a mole fraction of methyl groups originating from trimethylaluminum, relative to the total moles of methyl groups existing in the generated polymethylaluminoxane preparation is not more than 26 mol %; and(iii) the generated polymethylaluminoxane preparation has a viscosity of not more than 2.1×10−3 Pa·sec at 40° C.

The invention provides a preparation method of catalyst components for olefin polymerization and catalyst components obtained thereby. In the preparation method, a spherical catalyst is prepared by using a spherical magnesium halide adduct as the carrier and employing a complex of diol ester compounds and 1,3-diether compounds as the internal electron donor; and the reaction temperature of the internal electron donor and the washing degree of the catalyst are controlled, so that the obtained catalyst presents surprisingly high polymerization activity and high stereoregular directivity when used for olefin polymerization (especially propylene polymerization) and still maintains a high activity even if the concentration of alkyl aluminum is very low; and the obtained polymer has wide molecular weight distribution and relatively low ash content.