摘要:
A process for continuously producing a propylene-based block copolymer having an excellent impact resistance of the present invention, comprises:a first polymerization step comprising polymerizing .alpha.-olefin comprising propylene in the presence of hydrogen and a stereoregular polymerization catalyst comprising a solid catalyst component containing magnesium, titanium, halogen atom and an electron-donor compound, an organoaluminum compound and, if required, an electron-donar compound in a single polymerization reactor; anda second polymerization step comprising transporting .alpha.-olefin polymer obtained in the first polymerization step to a copolymerization reactor and copolymerizing propylene with .alpha.-olefin other than propylene in a gas phase substantially in the presence of said stereoregular polymerization catalyst used in the first polymerization step.
摘要:
A method for oligomerizing an .alpha.-olefin in the presence of a catalyst comprising a specific chromium compound including chromium atom and pyrrolyl group and an alkylaluminum compound, wherein the .alpha.-olefin is contacted to the chromium compound and the alkylaluminum compound without preliminarily contacting the chromium compound to either the .alpha.-olefin or the alkylaluminum compound.
摘要:
An image forming apparatus in which probability of sheet jamming is reduced and jammed sheet can be easily removed. The apparatus is provided with a guide plate, a movable guide plate defining a sheet feed passage therebetween, and a first sheet feed roller. A detachable sheet cassette is provided for attachment to a main body portion of the apparatus. In the sheet cassette, are provided a second sheet feed roller and a leaf spring which urges the second sheet feed roller toward the first sheet feed roller when the sheet cassette is attached to the main body portion. The sheet feed passage is opened by pivotal movement of the movable guide plate when the sheet cassette is detached from the main body portion, to thereby facilitate removal of the jamming sheet from the sheet feed passage.
摘要:
An electroposition process wherein solid metallic particles are produced in a fused salt electrolytic bath and dispersed therein to electrodeposit a metal or alloy thereof on a cathode so that the surface of the deposit is maintained smooth and flat. In order to produce particles of a desired metal or alloy, an auxiliary electrolytic means may be provided within an electrolytic cell so that such particles are generated in situ within the fused bath of such cell.
摘要:
An electrodeposition method of electrodepositing a material with a flat and smooth surface, in which an electrolytic condition such as a speed of movement of a cathode relative to an electrolyte, an electrolytic current density, a duty ratio of an interrupted electrolytic current or an interruption frequency of an electrolytic current is changed periodically from a normal value to another value and back again.
摘要:
A novel catalyst for hydrodealkylation of alkylaromatic compounds and a process for producing the catalyst are described. The catalyst comprises the compounds formed from either (a) graphite and (b) an alkali metal or (a) graphite, (b) an alkali metal and (c) at least one compound of a metal selected from the group consisting of Group VIII of the Periodic Table. The catalyst of this invention is capable of selectively producing Ar-C.sub.n.sub.-1 H.sub.2n.sub.-1 from Ar-C.sub.n H.sub.2n.sub.+1, wherein Ar is an aromatic radical.