46 results about "Hafnium compounds" patented technology

A method of making a superconducting structure includes depositing a metal alkoxide on a surface of a metal and hydrolyzing the metal alkoxide on the surface to form a pinhole-free film. The metal is a superconductor. The metal alkoxide may be a compound of formula (I):M4(OPrn)16  (I);where M is zirconium or hafnium, and the purity of the compound is at least 97% as measured by NMR spectroscopy.

This etching composition for etching hafnium compound, includes a fluoride compound and a chloride compound. This method for etching a substrate, includes etching a film which contains hafnium compound and is formed on a substrate by using an etching composition, wherein the etching composition contains a fluoride compound and a chloride compound.

The present invention provides a catalyst for olefin polymerization having high olefin polymerization activity without being accompanied by generation of an adhered polymer on the wall of a polymerization reactor and the wall of pipe line and generation of a locking massive polymer, and capable of manufacturing an olefin polymer industrially and stably for a long period of time. That is, the present invention related to a catalyst for olefin polymerization comprising [A1] a hafnium compound or a zirconium compound having at least one conjugated 5-membered ring ligand, [A2] a zirconium compound having at least one conjugated 5-membered ring ligand but different from [A1], and [B] phyllosilicate, and relates to a method of polymerizing or copolymerizing olefin in the presence of the catalyst.

The invention discloses an ethylene-bridged indenyl-fluorenyl zirconium (hafnium) compound as well as a preparation method and application thereof in oligomerization of propylene. The ethylene-bridged indenyl-fluorenyl zirconium (hafnium) compound can be obtained by virtue of firstly reacting an ethylene-bridged indenyl-fluorenyl ligand compound with an alkyl alkali metal in an organic medium and then adding ZrCl4 or HfCl4. The ethylene-bridged indenyl-fluorenyl zirconium (hafnium) compound disclosed by the invention is an efficient catalyst and has high catalytic activity when used for catalyzing oligomerization of propylene under relatively mild conditions and thus the propylene oligomer containing allyl end groups can be highly selectively obtained in the presence of an untreated alkyl aluminoxane co-catalyst; and meanwhile, the control of the molecular weight of the oligomer can be achieved by virtue of controlling polymerization conditions and the ethylene-bridged indenyl-fluorenyl zirconium (hafnium) compound has very high industrial application values and has the structure represented by the formula as shown in the specification.

The invention relates to a method for preparing C / SiC-HfC carbon fiber reinforced ultrahigh-temperature ceramic matrix composite, which comprises the following steps: introducing C organic precursor in C / SiC preform by vacuum pressure impregnation method or directly using C / C perform; combining with reaction melt impregnation method; and reacting silicon hafnium alloy with C to in-situ generate HfC-SiC. The obtained composite has high volume fraction of HfC; generated SiC and HfC have small grains to effectively improve the erosion resistance capability of materials. The method is applicable for composite, in site generates HfC phase in the process of preparing material and increases the volume fraction of hafnium compounds to enhance the erosion resistance capability.

A method of producing a phthaloyl dichloride compound, the method including: providing a compound represented by the following formula (1) and a compound represented by the following formula (2); and bringing the compound represented by the following formula (1) and the compound represented by the following formula (2) into reaction, so as to form a compound represented by the following formula (3), in the presence of at least one compound selected from a zirconium compound, a hafnium compound, and zinc oxide;wherein, in formulae, X represents a hydrogen atom, a halogen atom, a nitro group, a methyl group, or a methoxy group; when the X is plural, Xs may be the same or different from each other; n represents an integer of from 0 to 2; R represents a halogen atom, a chlorocarbonyl group, a low carbon number alkyl group, or a halogen-substituted low carbon number alkyl group; when the R is plural, Rs may be the same or different from each other; and m represents an integer of from 0 to 2.