14results about How to "High polymerization activity" patented technology

The invention discloses a silicon oxide microsphere as well as a preparation method and application thereof. The silicon oxide microspheres are large-aperture silicon oxide microspheres, the specific surface area is 395-750m < 2 > / g, the pore volume is 1.0-3.5 ml / g, and the average aperture is 17-50nm. The silicon oxide microspheres have the characteristics of large specific surface area, large pore volume and large pore diameter, and the catalyst prepared by using the silicon oxide microspheres as the carrier has the advantage that the activity is remarkably improved when the catalyst is applied to olefin polymerization reaction.

Under the load of 2.16 kg and at the temperature of 190 DEG C, the melt index is 600-2500 g / 10 min, the molecular mass distribution is 1.2-1.8, the melting point is 90-135 DEG C, the crystallinity is 50-90%, the true density is 0.930-0.970 g / cm < 3 >, the branching degree is 0-1.0 mol%, the bulk density is 0.30-0.55 g / cm < 3 >, and the average particle size is 200-1000 mm. An alkane solvent with the boiling point being 5-55 DEG C or a mixed alkane solvent with the saturated vapor pressure being 20-150 KPa at the temperature of 20 DEG C is used as a polymerization solvent, a single-active-center catalyst is used as a main catalyst, aluminoxane, modified aluminoxane, alkyl aluminum or halogenated alkyl aluminum is used as a cocatalyst, the polymerization temperature is 70-100 DEG C, the temperature difference in a kettle is smaller than 2.0 DEG C, the polymerization pressure is 1.0-4.2 MPa, and the reaction time is 1-2 hours. A process for the preparation of a reactor slurry polymerization of a feedstock comprising ethylene, hydrogen, and / or a comonomer. The preparation method is simple and easy to control, and the obtained powdery polyethylene is high in melt index, adjustable and controllable in average particle size, true density, melting point, crystallinity and the like, and narrow in particle size distribution.

The invention relates to a cycloolefin terpolymer, a preparation method thereof and an optical element. The preparation method of the cycloolefin terpolymer comprises the following steps: mixing an ethylene monomer, a cycloolefin monomer and a conjugated aryl-substituted olefin monomer, and carrying out polymerization reaction in the presence of a catalyst and a cocatalyst to prepare the cycloolefin terpolymer, the conjugated aryl substituted olefin monomer has the following structural characteristics: m is an integer from 1 to 10, and R1 is naphthyl, anthryl, phenanthryl, pyrenyl, acenaphthenyl or chrysenyl; the catalyst comprises a metallocene catalyst; the cocatalyst comprises one or more of an aluminum compound and a boron compound; the conditions of the polymerization reaction are as follows: the pressure is 2.2 MPa to 10 MPa. The polymerization activity of the preparation method is obviously improved, and the prepared cycloolefin terpolymer has relatively high refractive index and mechanical property and relatively low water absorption.

This invention discloses a method for preparing silica microspheres, the prepared silica microspheres, and their applications. The method for preparing silica microspheres includes: (1) heating a mixture of n-alkane and pitch under reflux to separate a solid product; (2) mixing the solid product from step (1) with a mixture of aromatics I, a first silicon source, a polyoxyethylene-polyoxypropylene-polyoxyethylene copolymer, and water to obtain a crystallization solution, followed by hydrothermal crystallization and calcination to obtain an intermediate product; (3) mixing the intermediate product from step (2), a second silicon source, a pore-forming agent, and water to obtain a slurry; then, spray-drying and calcining the slurry to obtain the silica microspheres. The silica microspheres prepared by this method have the advantages of large specific surface area, large pore volume, and large average pore size, which significantly improves polymerization activity in olefin polymerization reactions.

The invention provides a method for preparing bimodal / wide molecular weight distribution polyethylene by using a single reactor, which comprises the following steps of: catalyzing ethylene homopolymerization or copolymerization of ethylene and alpha-olefin by using a hydrocarbon solvent as a dispersing agent and using a vanadium polyethylene catalyst and aluminum alkyl as a main catalyst and a cocatalyst respectively, hydrogen is used as a polymer molecular weight regulator in the reaction process; wherein the vanadium polyethylene catalyst comprises a magnesium-containing carrier and a vanadium compound loaded on the magnesium-containing carrier, the total weight of the vanadium polyethylene catalyst is 100%, the mass content of active metal vanadium is not less than 3.8%, the average particle size of the vanadium polyethylene catalyst is 9.0-13.5 [mu] m, and the particle size distribution SPAN value is less than 1. The vanadium polyethylene catalyst used in the invention has higher polymerization activity, and the obtained polymer has higher apparent density and lower fine powder and oligomer, and can be used for developing special resins for high-strength films, pressure-resistant pipes and the like.

This invention provides a method in which the polymerization activity in the first and second polymerization steps is excellent, easily producing propylene-based block copolymers with high melt flow rates and a high proportion of propylene / α-olefin copolymer components. A method for manufacturing a propylene-based block copolymer includes using an olefin polymerization catalyst, performing a first polymerization step, and then performing a second polymerization step. The olefin polymerization catalyst comprises (A) a solid catalyst component for olefin polymerization and (B) an organoaluminum compound. The (A) solid catalyst component for olefin polymerization contains titanium, magnesium, halogen, and a 1,3-diether compound. The first polymerization step is performed at a temperature of 45-65°C, where olefins containing 95-100% by mass of propylene are polymerized to obtain a propylene-based polymer. The second polymerization step is performed at a temperature of 50-90°C, in the presence of the propylene-based polymer, where olefins containing 5% by mass and less than 95% by mass of propylene and α-olefins other than propylene are copolymerized to obtain a propylene / α-olefin copolymer.

A method for recovering organic tin in a vinyl ether compound transesterification kettle liquid, comprising the following steps: 1) taking the vinyl ether compound transesterification kettle liquid, cooling to-10-40 DEG C, standing, until crystals are precipitated in the transesterification kettle liquid, filtering, or, cooling to-10-40 DEG C, adding 0.1-5% of organic tin powder in mass fraction to the transesterification kettle liquid, stirring and mixing uniformly, then standing, until crystals are precipitated in the transesterification kettle liquid, filtering; 2) adding a basic solution with a concentration of 5-8 wt% to the crystals obtained by filtering, in a mass ratio of 1:0.5-10, and heating to 25-60 DEG C, until flocculent substances appear on the surface of the basic solution, and filtering the lower aqueous phase; 3) washing the crystals obtained by filtering with water, then washing with an organic solvent, drying, to obtain organic tin. The process condition is mild and the operation is convenient, the recovered organic tin can be used repeatedly, the production cost of enterprises is reduced, and environmental pollution is avoided.

The application discloses an unsymmetrical (alpha-diimine) nickel olefin catalyst based on a vinylidene acen as a skeleton, and a preparation method and application thereof. The structural formula of the catalyst is shown as formula (I), wherein X is chlorine or bromine. The catalyst has simple preparation process, and shows a result opposite to general rules when catalyzing ethylene polymerization, that is, a larger substituent group leads to a polymerization product with higher crystallinity. In addition, the catalyst also shows good thermal stability and polymerization activity, and has good industrial application prospect.

The present application relates to the field of catalysis and olefin polymerization, and discloses a reaction system for preparing a polar ethylene copolymer, application of the reaction system, the polar ethylene copolymer and a polymerization method of the polar ethylene copolymer.The reaction system comprises the following components: a) at least one metallocene compound; b) at least one alkyl aluminoxane; c) at least one organic aluminum compound AlR' m X 3‑m ; d) ethylene; and e) a monomer represented by formula I.The reaction system has the characteristics of high activity and low price when used for preparing the polar ethylene copolymer, and the prepared polar ethylene copolymer has a linear structure, and the polar comonomer can be uniformly distributed on the copolymer molecular chain, so that the prepared polar ethylene copolymer has the structural characteristics of both cyclic olefin copolymer and hydroxylated polyolefin material, has excellent barrier property, and can be used as a packaging material in the field of medicine and other fields with high barrier property requirements.

This invention discloses a sterically hindered, biasymmetric (α-diimine) nickel-olefin catalyst based on acenaphthoquinone as its framework, its preparation method, and its applications. The catalyst's structural formula is shown in Formula (I), where X is chlorine or bromine. The catalyst has a simple preparation process and, when used as a co-catalyst, can produce ultra-high molecular weight polyethylene in ethylene polymerization without affecting the degree of branching. Furthermore, the catalyst exhibits good thermal stability and polymerization activity, showing promising prospects for industrial applications. Formula (I)

The invention discloses a supported metallocene catalyst as well as a preparation method and application thereof. The catalyst comprises a metallocene compound, a cocatalyst and a carrier, the carrier is mesoporous silica with dual pore size distribution, the metallocene compound has a structure as shown in (I), L1 and L2 are respectively and independently cyclopentadienyl and fluorenyl, and L1 and L2 are the same or different; r1 and R2 are respectively substituent groups on L1 and L2, and R1 and R2 are respectively and independently C1-C6 alkyl groups or aryl groups; p and q are the numbers of R1 and R2 respectively, and are 0, 1, 2 or 3 respectively; z is-C (CH3) 2-or-CPh2-, wherein Ph is phenyl; m is Ti, Zr or Hf; and X is halogen and C1-C4 alkyl. The catalyst has high catalytic activity and can be used for catalyzing ethylene polymerization to obtain ultra-high molecular weight polyethylene.

The invention provides a catalyst system capable of regulating and controlling activity as well as a preparation method and application of the catalyst system. The catalyst system comprises a reaction product with a titanium-containing component, an aluminum alkyl compound and an external electron donor compound as inner components, and the external electron donor compound comprises a diene terephthalate compound and an optional alkyl dialkoxy silane compound. The polymerization activity of the obtained catalyst system is improved, and the hydrogen regulation sensitivity is improved; the polymerization activity of the catalyst can be adjusted by changing the addition amount of the external electron donor compound.

This invention discloses an olefin polymerization catalyst, its preparation method, and its application. The olefin polymerization catalyst is a compound of formula (1) with the structure shown below. This invention uses the compound of formula I as a starting material to synthesize the target product simply and efficiently, effectively reducing the synthesis difficulty of the compound of formula (1). At the same time, this catalyst exhibits high polymerization activity and good comonomer insertion rate in the homopolymerization of ethylene, copolymerization of ethylene and α-olefins, and copolymerization of ethylene and cyclic olefins.

The invention provides an ethylene in-situ copolymerization catalyst system and application thereof. The ethylene in-situ copolymerization catalyst system comprises an ethylene oligomerization catalyst, a metallocene copolymerization catalyst and an organic aluminum compound; the ethylene oligomerization catalyst is prepared by loading a Zr compound on an organic polymer carrier containing [SO2NCO] groups, the metallocene copolymerization catalyst is composed of an organic polymer carrier containing a [SO3] group, a metallocene compound and a cocatalyst. The ethylene in-situ copolymerization catalyst system can be polymerized to obtain linear low density polyethylene (LLDPE).