99results about How to "High isotacticity" patented technology

New ligands, compositions, metal-ligand complexes and arrays with pyridylamine ligands are disclosed that catalyze the polymerization of monomers into polymers. Certain of these catalysts with hafnium metal centers have high performance characteristics, including higher comonomer incorporation into ethylene/olefin copolymers, where such olefins are for example, 1-octene, isobutylene or styrene. Certain of the catalysts are particularly effective at polymerizing propylene to high molecular weight isotactic polypropylene in a solution process at a variety of polymerization conditions.

The present invention discloses preparation of solid catalyst for olefin polymerization. The preparation process has lowered contact temperature between the component A of dialkoxy magnesium compound and the component B titanium compound, and high bulk density of the component A or raised dropped amount of the component B to raise the bulk density of the polymer. The catalyst prepared through the improved process has high activity, high isotactic degree and high hydrogenation regulating performance as well as capacity of raising the bulk density of the polymer.

The invention provides a dialkoxyl magnesium supported solid catalyst. The catalyst is prepared by complexing 1, 3-di-ethers into an internal electron donor or complexing 1, 3-di-ethers and esters into internal electron donors by taking a dialkoxyl magnesium compound as the carrier. The invention further provides a method for preparing the solid catalyst and an olefin polymerization catalyst containing the solid catalyst. The dialkoxyl magnesium supported solid catalyst shows high activity through the catalyst obtained by using different 1, 3-di-ethers as well as the complex formulation of 1, 3-di-ethers and esters.

The invention relates to a method for preparation of high performance carbon fiber protofilament by blending method. High isotactic polyacrylonitrile and high molecular weight polyacrylonitrile are mixed evenly, and then dissolved in dimethylsulfoxide (DMSO) for the preparation of a polyacrylonitrile spinning solution; then the spinning solution is deaerated, filtered, and measured, then extruded through a spinneret, and solidified for forming by wet spinning in a DMSO aqueous solution in a certain concentration; and high strength polyacrylonitrile based carbon fiber is prepared from nascent fiber by boiling water drafting, washing with water, drying densification and steam stretching. Compared with the prior art, the polyacrylonitrile based carbon fiber protofilament prepared from the high isotactic polyacrylonitrile and the high molecular weight polyacrylonitrile by the blending method has the characteristics of regular structure, less fineness, high strength and the like, and is used in the preparation of high performance carbon fiber.

Disclosed is a process for producing a procatalyst composition having an amide ester internal electron donor. The process includes pre-halogenating a procatalyst precursor before reaction with the amide ester and forming the procatalyst composition. Ziegler-Natta catalyst compositions containing the present procatalyst composition exhibit improved catalyst activity and/or improved catalyst selectivity and produce propylene-based olefins with broad molecular weight distribution.

Disclosed are procatalyst compositions having an internal electron donor which includes a substituted amide ester and optionally an electron donor component. Ziegler- Natta catalyst compositions containing the present procatalyst compositions exhibit improved catalyst activity and/or improved catalyst selectivity and produce propylene-based olefins with broad molecular weight distribution.

Disclosed are halogenated amide esters that are suitable as internal electron donors in procatalyst compositions. Ziegler-Natta catalyst compositions containing the present procatalyst compositions exhibit improved catalyst activity and/or improved catalyst selectivity and produce propylene-based olefins with broad molecular weight distribution.

The invention relates to a dialkoxyl magnesium carrier, which is a product produced by a reflux reaction of magnesium, an alcohol and mixed halogenated agents under an inert atmosphere. The mixed halogenated agents are iodine and magnesium chloride, and the weight ratio between iodine and magnesium chloride is 0.05:1-1:0.01. The dialkoxyl magnesium carrier is spheroid with uniform particle size distribution, excellent particle morphology and high bulk density. A solid catalyst component and a catalyst based on this carrier for olefin polymerization are also provided, and olefin polymers having a wide molecular weight distribution, good stereoregularity, excellent particle morphology and a low content of fine powders can be obtained.

The present invention relates to a solid, particulate catalyst component having an mean particle size range of 5 to 200 μm and comprising a compound of a Group 2 metal, a compound of a transition metal of Group 4 to 6, and at least two internal electron donors being different to each other and being non-phthalic organic compounds selected from (did)esters of non-phthalic carboxylic (did)acids, 1,3-diet hers and did-esters of 1,3-diol compounds and derivatives thereof, and wherein the solid particulate catalyst component is free of any external support material. The invention relates also to the preparation of the catalyst component and a polymerization process for producing propylene polymers.

The invention designs an ester compound having the general formula (I), which is used as an internal electron donor of a titaniferous catalyst component and applied to the titaniferous catalyst component for olefin polymerization. A 1-subsituted benzoyloxy-3-alkoxypropane compound using the general formula (I) is used as the titaniferous catalyst component synthesized by the internal electron donor. When a catalyst made from the titaniferous catalyst component is used for olefin polymerization, especially propylene polymerization, the catalyst has high catalytic activity; an obtained polymer has high isotacticity and wide molecular weight distribution.

The invention provides a catalyst component for olefin polymerization. The catalyst component comprises Ti, Mg, halogen, at least one electron donor compound and 1-99% of an olefin polymer. The catalyst component is used for olefin polymerization and has characteristics of high activity, high accumulation density and low fine-powder content. The catalyst component is free of ageing influences during room-temperature storage. Polymer particles are not liable to break. The catalyst component is especially suitable for synthesis of in-reactor alloying polymers with high rubber contents.

The invention discloses a modified high-crystallinity polypropylene composite material which comprises the following components in part by weight: 75-80 parts of high-crystallinity polypropylene, 2-10parts of toughening agent, 5-15 parts of special ultrafine talc powder, 5-15 parts of specially-made hollow glass micro-bead, 0.5-3 parts of scratch-resistant agent, 0.2-0.8 part of anti-oxidant complex, 0.1-0.5 part of weathering-resistant compound aid and 0.1-0.8 part of lubricating agent. The invention further discloses a preparation method of the modified high-crystallinity polypropylene composite material. The modified high-crystallinity polypropylene composite material and the preparation method thereof disclosed by the invention have the benefits that the rigidity of the modified high-crystallinity polypropylene composite material can be improved, and the post-contraction after a part is formed can be reduced, so that the better dimension stability can be maintained; meanwhile, asthe hollow glass micro-bead has the hollow properties after surface treatment with an aluminum-titanium coupling agent, the material density is reduced while the material physical properties are maintained.

The present invention relates to the use of oxalic acid diamides as modifiers in conjunction with solid Ziegler-Natta type catalyst in processes in which polyolefins such as polypropylene are produced. The modified catalyst compositions produce polypropylene with good productivity and higher sterospecificity than systems without such modification.

The invention discloses a propylene polymerization catalyst, a preparation method and application thereof. The catalyst comprises a main catalyst, a compound external electron donor and a cocatalyst, wherein the compound external electron donor comprises an external electron donor I and an external electron donor II with the molar ratio of 1:(0.01-100); the general formula of the external electron donor I is R1nSi(OR2)4-n or R3R4Si(OR5)2, and the general formula of the external electron donor II is (R6O)(R7O)Si(R8O)(R9O). The invention also discloses a preparation method of the main catalyst in the catalyst and the application thereof in propylene polymerization reaction and copolymerization reaction of propylene and C3-C20 alpha-olefin. The catalyst provided by the invention is high in catalytic activity, the propylene as a product obtained from catalysis has the characteristics of high isotacticity, high melt index and high melting point; the preparation method of the catalyst is simple and environmental-friendly and is applicable to processes of bulk polymerization, slurry polymerization, gaseous polymerization or combined polymerization of the propylene.

The invention discloses a process for preparing high-performance propylene polymers, the process utilizing a high activity, highly stereoselective Ziegler-Natta catalyst and two or more stages of polymerization carried out under different hydrogen concentrations to prepare propylene polymers having broad molecular weight distribution, wherein non-unifomess of isotacticity of molecular chains of the final propylene polymers is improved by adjusting or controlling stereoselectivity of catalytic active sites under different hydrogen concentrations, namely, making the low molecular weight fraction of the polymers having a higher isotacticity and making the high molecular weight fraction of the polymers having a lower isotacticity, thereby overcoming the drawbacks of the propylene polymers having broad molecular weight distribution known in the art. The resulting final polymers have excellent combined properties, in particular, remarkably improved mechanical properties.

The present technology relates to a pre-polymerized catalyst component for the polymerization of olefins, characterized by a non-stereospecific solid catalyst component comprising Ti, Mg and a halogen and an amount of a (co)polymer of an alpha-olefin CH₂═CHR¹, where R is a C₁-C₁₂ hydrocarbon group ranging from 0.1 to 500 g per g of said solid catalyst component. In some embodiments, the (co)polymer is characterized by an isotacticity, expressed in terms isotactic pentads, of higher than 60 molar % and an intrinsic viscosity, measured in tetraline at 135° C., of at least 1.0 dL/g.

The invention provides stiffened polypropylene resin and a preparation method thereof. The preparation method comprises that ethylene and propylene undergo a polymerization reaction under catalysis of a Ziegler-Natta catalyst by a gas phase hydrogen regulation method, and a stiffening nucleating agent is used in the powder granulation stage so that the stiffened polypropylene resin is obtained, wherein the internal electron donor of the Ziegler-Natta catalyst is a diether-type internal electron donor. The internal electron donor can improve the catalytic activity and stereospecificity of the catalyst, improve polymer isotacticity, reduce xylene soluble content of polypropylene resin and improve polypropylene resin rigidity. In the extrusion granulation in the later period, the stiffening nucleating agent is used, can refine the grains, can improve the crystallization properties of the resin and can enhance rigidity.

The invention discloses an olefin polymer-containing catalyst component used for olefin polymerization. The catalyst component is obtained by pre-polymerizing an olefin polymerization catalyst, an activator and olefin, and then storing offline, wherein the conditions of storing offline are as follows: the storage period is greater than 1 minute and less than 10 years, the storage temperature is -50 DEG C to 80 DEG C, A(Time, Temp) of the catalyst component is greater than or equal to A(0-1, Temp)*50%(g polymer/g reactive metal center), and when the fluctuation range of the storage temperature is within -10 DEG C to 10 DEG C, A(Time2, Temp) is greater than or equal to A(Time1, Temp)*50%(g polymer/g reactive metal center). The invention also discloses a catalyst used for olefin polymerization, comprising the olefin polymer-containing catalyst component, an aluminium compound and optionally, an external electron donor compound. When the catalyst component and the catalyst are applied in olefin polymerization, the problems of aggregation, caking and the like caused by catalyst particle breakage and local hot points can be avoided, and the fine powder content can be reduced.

The invention discloses a preparation method of high-tacticity polypropylene. The method is characterized in that a monomer propylene is homopolymerized with MgCl2/ID/TiCl4 (ID is an internal electron donor) supported catalyst as a main catalyst, mixed trialkylaluminum as a cocatalyst and R1R2Si(OCH3)2 as an external electron donor to prepare the high-tacticity polypropylene; and the mixed cocatalyst is trimethylaluminum, triethylaluminum, a triisobutyl compound, or an arbitrary mixture thereof. The spherical efficient supported Ziegler-Natta catalyst with magnesium chloride as a carrier is adopted in the invention, so the high-tacticity polypropylene polymerized through above steps are nearly spherical or regularly spherical particles with the diameter of 0.5-2mm, and the fluidity of the particles is good.

The invention provides a polypropylene non-woven fabric and a making method of the polypropylene non-woven fabric. The molecular weight distribution index of polypropylene in the polypropylene non-woven fabric is 2.5-5.5, and the high molecular trailing index PIHT in molecular weight distribution width is greater than 1.9. The polypropylene non-woven fabric has high strength.

The invention provides a late transition metal catalyst for olefin polymerization with a structural formula (I), which is characterized by introducing a wedge-shaped dendritic molecule having certain space volume and more symmetrical spatial position of substituent into a ligand structure, successfully avoiding chain transfer reaction of propylene and effectively preventing the propylene from attacking the active site from the side chain. When the catalyst for the olefin polymerization is used for propylene polymerization together with an aluminium alkyl compound, the polymerization activity is remarkably improved, the activity of the catalyst can reach 105g polypropylene/mol Fe*h, and in particular, the number-average molecular weight and degree of isotacticity of the polymerization product are enhanced. The number-average molecular weight is far more than 15000g/mol, and the degree of isotacticity is close to 85%. M is a transition metal selected from Fe, Co or Ni.