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    LOW GEL POLYETHYLENE FILM
    2.
    发明专利
    LOW GEL POLYETHYLENE FILM 未知

    公开(公告)号：CA2141474A1

    公开(公告)日：1996-01-07

    申请号：CA2141474

    申请日：1995-01-31

    Applicant: UNION CARBIDE CHEM PLASTIC

    Inventor： DANIELL PAUL T ,  TILSTON MICHAEL W ,  SPRIGGS THOMAS E ,  WAGNER BURKHARD E ,  RAMAMURTHY ARAKALGUD V

    IPC: C08J5/18 ,  C08F2/00 ,  C08F2/34 ,  C08F4/60 ,  C08F4/654 ,  C08F10/00 ,  C08F210/02 ,  C08F297/08 ,  C08L23/08 ,  C08L23/16 ,  C08F210/16 ,  C08F4/646

    Abstract: A gas phase process for the production of a polyethylene blend comprising contacting ethylene and at least one alpha-olefin comonomer having 3 to 8 carbon atoms with a magnesium/titanium based catalyst system including an activator and a cocatalyst in each of two fluidized bed reactors connected in series, under polymerization conditions, with the provisos that: (a) the mixture of ethylene copolymer matrix and active catalyst formed in the first reactor in the series is transferred to the second reactor in the series; (b) other than the active catalyst referred to in proviso (a) and the cocatalyst referred to in proviso (e), no additional catalyst is introduced into the second reactor; (c) in the first reactor in which a low melt index copolymer is made: (1) the alpha-olefin is present in a ratio of about 0.01 to about 0.4 mole of alpha-olefin per mole of ethylene; (2) optionally, hydrogen is present in a ratio of about 0.001 to about 0.3 moles of hydrogen per mole of ethylene; and (3) the ethylene partial pressure is at least about 40 pounds per square inch; and (d) in the second reactor in which a high melt index copolymer is made: (1) the alpha-olefin is present in a ratio of about 0.01 to about 0.6 mole of alpha-olefin per mole of ethylene; (2) hydrogen is present in a ratio of about 1 to about 2.5 moles of hydrogen per mole of ethylene; and (3) diethyl zinc is added in an amount of about 2 to about 40 moles of diethyl zinc per mole of titanium; and (e) additional hydrocarbyl aluminum cocatalyst is introduced into the second reactor in an amount sufficient to restore the level of activity of the catalyst transferred from the first reactor to about the initial level of activity in the first reactor.

    3.
    发明专利
    未知

    公开(公告)号：BRPI0513663A

    公开(公告)日：2008-05-13

    申请号：BRPI0513663

    申请日：2005-08-09

    Applicant: UNION CARBIDE CHEM PLASTIC

    Inventor： SPRIGGS THOMAS E ,  TURNER MICHAEL D ,  WAGNER ERIC BURKHARD ,  LEVANDOVSKY ARTEM ,  LACKS DANIEL J

    IPC: C08F10/00 ,  C08F4/02

    Abstract: A Ziegler-Natta procatalyst composition in the form of solid particles and comprising magnesium, halide and transition metal moieties, said particles having an average size (D50) of from 10 to 70 μm, characterized in that at least 5 percent of the particles have internal void volume substantially or fully enclosed by a monolithic surface layer (shell), said layer being characterized by an average shell thickness/particle size ratio (Thickness Ratio) determined by SEM techniques for particles having particle size greater than 30 μm of greater than 0.2.

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