摘要:
Aluminum orthophosphate is prepared by combining a source of phosphate ions with an aluminum salt to form a concentrated mass, combining with sufficient neutralizing agent to partially neutralize, and aging until gellation occurs. The resulting aluminum phosphate is particularly suited for use as a base for a chromium olefin polymerization catalyst.
摘要:
A supported chromium oxide polymerization catalyst is prepared by a process which includes the steps of heating silica-supported chromium oxide or a substance oxidizable to chromium oxide in a nonoxidizing atmosphere in the presence of formaldehyde or a compound thermally decomposable to formaldehyde, and then heating the thus-treated catalyst in an oxygen-containing atmosphere. The temperatures of the respective heating steps can vary depending upon the properties desired in the polymer to be produced with the invention catalyst; however, the invention catalyst preparation method enables the production of a catalyst having a high melt index potential at relatively low treatment temperatures, e.g. no higher than about 600.degree. C.
摘要:
Aluminum orthophosphate is prepared by combining a source of phosphate ions with an aluminum salt to form a concentrated mass, combining with sufficient neutralizing agent to partially neutralize, and aging until gellation occurs. The resulting aluminum phosphate is particularly suited for use as a base for a chromium olefin polymerization catalyst.
摘要:
This invention provides a process for producing a catalyst composition comprising contacting at least one group 4 metallocene, at least one organoaluminum compound, and at least one solid. The solid is selected from the group consisting of titanium tetrafluoride, zirconium tetrafluoride, and a treated solid oxide compound. The treated solid oxide compound comprises a solid oxide compound having titanium tetrafluoride or zirconium tetrafluoride deposited on the surface of the solid oxide compound. The solid oxide compound comprises oxygen and at least one element selected from the group consisting of groups 2-9 and 11-17 of the Periodic Table of Elements, including lanthanides and actinides. This invention also provides the catalyst composition produced by this process.
摘要:
A process is provided to produce a composition of matter. The process comprises contacting at least one organometal compound, at least one solid mixed oxide compound, and at least one organoaluminum compound to produce the composition.
摘要:
This invention provides compositions for polymerizing at least one monomer to produce a polymer. The compositions are produced by a process comprising contacting at least one organometal compound, at least one organoaluminum compound, and at least one treated solid oxide compound. The treated solid oxide compound is produced by a process comprising contacting at least one solid oxide compound with at least one electron-withdrawing anion source compound and at least one metal salt compound.
摘要:
High surface are aluminas are pre-calcined to form gamma-alumina. In one embodiment, the gamma-alumina is treated with an anhydrous solution of a fluorine-containing compound. In a second embodiment, alumina is precipitated in the pores of the gamma-alumina and then treated with a fluorine-containing compound. In a third embodiment a cogel of aluminum trifluoride and aluminum hydroxide is prepared. The three inventive fluorided alumina supports can be impregnated with a transition metal, preferably chromium, to form a catalyst system which can be used to polymerize mono-1-olefins.
摘要:
High surface are aluminas are pre-calcined to form gamma-alumina. In one embodiment, the gamma-alumina is treated with an anhydrous solution of a fluorine-containing compound. In a second embodiment, alumina is precipitated in the pores of the gamma-alumina and then treated with a fluorine-containing compound. In a third embodiment a cogel of aluminum trifluoride and aluminum hydroxide is prepared. The three inventive fluorided alumina supports can be impregnated with a transition metal, preferably chromium, to form a catalyst system which can be used to polymerize mono-1-olefins.
摘要:
A catalyst support based on aluminum polyphosphate or polyphosphoric acid-impregnated alumina is provided by two alternative techniques. In the first embodiment, an aluminum polyphosphate composition is heated in a dry atmosphere and thereafter impregnated with a zerovalent chromium component under anhydrous conditions. The resulting catalyst is active for olefin polymerization. In the second embodiment, alumina is impregnated with a polyphosphoric acid composition. This resulting polyphosphoric acid impregnated alumina can be used as a support for zerovalent chromium or can be impregnated with a chromium component and oxidized to give an active hexavalent chromium species. The resulting catalysts are advantageous because of their unusual sensitivity to hydrogen thus allowing great leeway in molecular weight control.