摘要:
The present invention relates to a metallocene catalyst system comprising an antistatic agent and a preparation method for polyolefin using the same. The present invention can not only maintain the inherent activity of the catalyst but also minimize reactor fouling and particle agglomeration in the preparation of a polyolefin using the gas-phase polymerization process, thereby allowing to the process to be operational with more stability.
摘要:
The present invention is directed to silicon-containing fumaric acid esters of the Formulae I-IV. The silicon- containing fumaric acid esters of Formulae I-IV are useful in transplantation medicine and for the treatment of autoimmune diseases and autoimmune-related diseases. (I), (II), (III) & (IV)
摘要:
A method for producing a polydiene, the method comprising the steps of: (i) forming an active catalyst by combining a lanthanide-containing compound, an alkylating agent, and a halogen source in the substantial absence of a sulfone, a sulfoxide, and a phosphine oxide; and (ii) polymerizing conjugated diene monomer in the presence of the active catalyst and a polymerization modulator selected from the group consisting of a sulfone, a sulfoxide, and a phosphine oxide.
摘要:
Method employing a supported metallocene catalyst composition in the production of an isotactic ethylene propylene co-polymer. The composition comprises a metallocene component supported on a particulate silica support having average particle size of 10- 40microns, a pore volume of 1.3-1.6 ml/g, a surface area of 200-400 m 2 /g. An alkylalumoxane co catalyst component is incorporated on the support. The isospecific metallocene is characterized by the formula (1): B (CpRaRb)(FlR' 2 )MQ n or by the formula (2): B'(Cp'R'aR'b)(F1')M'Q' n' In the formulas Cp and Cp' are substituted cyclopentadienyl groups, F1 and F1' are fluorenyl groups, and B and B' are structural bridges. R' are substituents at the 2 and 7 positions, Ra and R'a are substituents distal to the bridge, and Rb and R'b are proximal to the bridge. M and M' are transition metals, Q' is a halogen or a C 1- C 4 alkyl group; and n' is an integer of from 0-4.
摘要:
This invention relates to a polyethylene film having a MD 1% Secant Modulus of 220 MPa or more and an MD Elmendorf Tear of Y g/micron, where Y > -0.4515(Dart Drop in g/micron) + 33.3 g/microns, wherein the MD Elmendorf tear is at least 11.8 g/micron.
摘要:
The reaction of halo-boron compounds (B-X compounds, compounds having one or more boron-halogen bonds) with silanes provides boranes (B-H compounds, compounds having one or more B-H bonds) and halosilanes. Inorganic hydrides, such as surface-bound silane hydrides (Si-H) react with B-X compounds to form B-H compounds and surface-bound halosilanes. The surface bound halosilanes are converted back to surface- bound silanes electrochemically. Halo-boron compounds react with stannanes (tin compounds having a Sn-H bond) to form boranes and halostannanes (tin compounds having a Sn-X bond). The halostannanes are converted back to stannanes electrochemically or by the thermolysis of Sn-formate compounds. When the halo-boron compound is BCI 3 , the B-H compound is B 2 H 6 , and where the reducing potential is provided electrochemically or by the thermolysis of formate.
摘要:
Supported catalysts include a solid support such as silica that is functionalized to have inorganic acid functional groups attached thereto. Active catalyst particles are supported on the functionalized support material. The acid functionalized support material is made by reacting a solid support with an inorganic acid containing agent such as sulfuric acid or para-toluene sulfonic acid. An organic anchoring agent is used to form and anchor catalyst nanoparticles to the acid functionalized support material. The supported catalyst can be sized and shaped for use in any type of reactor, including a fixed bed or fluidized bed reactor. The methods of the present invention also include a process for the direct synthesis of hydrogen peroxide using the supported catalyst.
摘要:
A method of forming a polyolefin catalyst component includes halogenating metal complexes. The metal complexes result from reacting a metal alkoxide with an alcohol-ether. A particular non-limiting example is a magnesium complex formed by reacting magnesium alkoxide with an ethylene alcohol-ether, and then chlorinating the magnesium complex. Catalyst components, catalysts, catalyst systems, polyolefin polymers and methods of making each are disclosed.