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    Processes for transitioning between chrome-based and mixed polymerization catalysts
    4.
    发明授权
    Processes for transitioning between chrome-based and mixed polymerization catalysts 有权
    铬基和混合聚合催化剂之间过渡的方法

    公开(公告)号：US06833417B2

    公开(公告)日：2004-12-21

    申请号：US10835412

    申请日：2004-04-29

    申请人： Fred David Ehrman ,  Mark Bradley Davis ,  Ronald Steven Eisinger ,  Mark Gregory Goode ,  Michael Allen Kinnan

    发明人： Fred David Ehrman ,  Mark Bradley Davis ,  Ronald Steven Eisinger ,  Mark Gregory Goode ,  Michael Allen Kinnan

    IPC分类号： C08F234

    CPC分类号： C08F10/00 ,  C08F2/38 ,  C08F4/65912 ,  C08F4/65925 ,  C08F210/16 ,  C08F2410/05 ,  Y10S526/901 ,  C08F4/22 ,  C08F2/34 ,  C08F2/001 ,  C08F2/42 ,  C08F210/14 ,  C08F2500/18

    摘要： A process of transitioning from a first polymerization reaction conducted in the presence of a mixed catalyst system to a second polymerization reaction conducted in the presence of a chrome-based catalyst system is disclosed, the polymerization reactions being conducted in one embodiment in a polymerization zone of a gas phase fluidized bed reactor which contains a fluidized bed of polymer particles by the essentially continuous passage of monomer gases through the polymerization zone, comprising: a) discontinuing the introduction of the mixed catalyst system into the reactor; b) maintaining polymerization conditions in the reactor and permitting polymerization to continue for a period of time to allow the components of the mixed catalyst system present in the reactor to produce additional polymer particles; c) introducing a deactivating agent into the fluidized bed in an amount sufficient to deactivate the mixed catalyst system; d) establishing optimal conditions within the reactor for the chrome-based catalyst system; and e) introducing the chrome-based catalyst system into the reactor characterized in that the amount of polymer particles in the fluidized bed is substantially maintained in the polymerization zone during the transition steps.

    摘要翻译： 公开了一种从在混合催化剂体系存在下进行的第一聚合反应转变为在铬基催化剂体系存在下进行的第二次聚合反应的过程，聚合反应在一个实施方案中在聚合反应区 气相流化床反应器，其通过基本上连续通过单体气体通过聚合区域包含聚合物颗粒的流化床，包括：a）停止将混合催化剂体系引入反应器; b）保持聚合条件在 反应器并允许聚合持续一段时间以允许存在于反应器中的混合催化剂体系的组分产生另外的聚合物颗粒; c）以足以使混合催化剂体系失活的量向流化床中引入失活剂 ; d）在反应器内为t建立最佳条件 他的铬基催化剂体系; 将铬基催化剂体系引入到反应器中，其特征在于在过渡步骤期间流化床中的聚合物颗粒的量基本上保持在聚合区中。

    Gas phase polymerization process
    8.
    发明授权
    Gas phase polymerization process 失效
    气相聚合法

    公开(公告)号：US06753390B2

    公开(公告)日：2004-06-22

    申请号：US10368786

    申请日：2003-02-18

    申请人： Fred David Ehrman ,  Michael Elroy Muhle ,  Pradeep Pandurang Shirodkar ,  Keith Wesley Trapp

    发明人： Fred David Ehrman ,  Michael Elroy Muhle ,  Pradeep Pandurang Shirodkar ,  Keith Wesley Trapp

    IPC分类号： C08F234

    CPC分类号： C08F10/00 ,  C08F4/65912 ,  C08F4/65916 ,  C08F4/65925 ,  C08F210/16 ,  Y10S526/901 ,  Y10S526/905 ,  C08F4/65904 ,  C08F2/34 ,  C08F210/14 ,  C08F2500/07 ,  C08F2500/12 ,  C08F2500/18

    摘要： A gas phase polymerization process for producing a polyolefin composition is described, which includes passing a gaseous stream containing hydrogen gas and one or more monomers, including ethylene monomers, through a reactor that includes a fluidized bed, under reactive conditions, in the presence of a catalyst that includes metallocene, to provide a polyolefin composition, wherein in one embodiment the fluidized bulk density is 60% or more of the settled bulk density (or, a voidage of 40% or less); and wherein the voidage is controlled by a number of factors including, in certain embodiments, (a) the reactor temperature being maintained at 100° C. or below; (b) the molar ratio of hydrogen gas to ethylene introduced into the reactor being 0.015 or below.

    摘要翻译： 描述了一种用于生产聚烯烃组合物的气相聚合方法，其包括在反应条件下，在反应条件下，将含有氢气和一种或多种单体（包括乙烯单体）的气流通过包含流化床的反应器 包括茂金属的催化剂，以提供聚烯烃组合物，其中在一个实施方案中，流化体积密度为沉降堆积密度（或空隙率为40％以下）的60％或更多。 并且其中所述空隙率由许多因素控制，包括在某些实施方案中，（a）反应器温度保持在100℃或更低; （b）引入反应器的氢气与乙烯的摩尔比为0.015以下。