Process for preparing polyethylene
    1.
    发明授权
    Process for preparing polyethylene 失效
    制备聚乙烯的方法

    公开(公告)号:US5684097A

    公开(公告)日:1997-11-04

    申请号:US475842

    申请日:1995-06-07

    摘要: A process for producing polyethylene compositions in the presence of a catalytic system of ethylene polymerizing catalyst and cocatalyst in a multistage continuous reaction sequence consisting of successive liquid phase and gas phase polymerizations is disclosed. In the first step of the process, ethylene and optionally hydrogen and comonomer are polymerized in a first loop reactor in a low boiling hydrocarbon medium in the presence of ethylene polymerizing catalyst and cocatalyst. The reaction mixture is then removed and then transferred to a second loop reactor where polymerization is continued by addiing ethylene, hydrogen and optionally inert hydrocarbon, comonomers and cocatalysts. Thereafter, the reaction mixture is removed from the second loop reactor along with an essential part of the reaction medium and transferred to a gas phase reactor where polymerizing is continued in the presence of added ethylene and optionally hydrogen, comonomers and cocatalysts to form an end product. The residence time and reaction temperature being such that the proportion of the ethylene polymer produced in the first loop reactor to the end product of the process is between 1-20%.

    摘要翻译: 在由连续液相和气相聚合组成的多级连续反应序列中,在乙烯聚合催化剂和助催化剂催化体系存在下生产聚乙烯组合物的方法。 在该方法的第一步中,在乙烯聚合催化剂和助催化剂存在下,乙烯和任选的氢和共聚单体在第一回路反应器中在低沸点烃介质中聚合。 然后除去反应混合物,然后转移到第二环管反应器中,其中通过加入乙烯,氢气和任选的惰性烃,共聚单体和助催化剂继续聚合。 此后,将反应混合物与反应介质的主要部分一起从第二环管反应器中除去,并转移到气相反应器中,在气相反应器中,在加入的乙烯和任选的氢,共聚单体和助催化剂的存在下,继续聚合以形成最终产物 。 停留时间和反应温度使得在第一回路反应器中产生的乙烯聚合物与该方法的最终产物的比例为1-20%。

    Multi-stage process for producing polyethylene
    2.
    发明授权
    Multi-stage process for producing polyethylene 失效
    生产聚乙烯的多阶段工艺

    公开(公告)号:US5326835A

    公开(公告)日:1994-07-05

    申请号:US920569

    申请日:1992-08-20

    摘要: The invention concerns a multi-stage process for producing polyethylene having a bimodal and/or broad molecular weight distribution in the presence of an ethylene polymerizing catalyst system in a multistep reaction sequence, in which the first reaction step is a liquid phase polymerization step and the second reaction step is formed by one or more gas-phase polymerization steps. According to the process of the invention in the first reaction step ethylene is polymerized in a loop reactor (10) in an inert low-boiling hydrocarbon medium the residence time being at least 10 minutes, reaction mixture is discharged from the loop reactor (10) and at least a substantial part of the inert hydrocarbon mixture is separated and the polymer is transferred into one or more gas-phase reactors (30), where the polymerization is completed in the presence of ethylene and optionally hydrogen and a comonomer. As an inert hydrocarbon medium in the loop reactor (10) propane can be used and the polymerization can be carried out also so that the mixture of inert hydrocarbon, monomer, hydrogen and optional comonomer is under supercritical conditions.

    摘要翻译: PCT No.PCT / FI91 / 00406 Sec。 371日期:1992年8月20日 102(e)日期1992年8月20日PCT 1991年12月20日PCT PCT。 出版物WO92 / 12182 日本1992年7月23日。本发明涉及在多步反应序列中在乙烯聚合催化剂体系存在下生产具有双峰和/或宽分子量分布的聚乙烯的多阶段方法,其中第一反应步骤为 通过一个或多个气相聚合步骤形成液相聚合步骤和第二反应步骤。 根据本发明在第一反应步骤中的方法,乙烯在环状反应器(10)中在惰性低沸点烃介质中聚合,停留时间为至少10分钟,反应混合物从环管反应器(10)排出, 并且将至少大部分惰性烃混合物分离并将聚合物转移到一个或多个气相反应器(30)中,其中聚合在乙烯和任选的氢气和共聚单体存在下完成。 作为环管反应器(10)中的惰性烃介质,可以使用丙烷,也可以进行聚合,使得惰性烃,单体,氢和任选的共聚单体的混合物处于超临界条件下。

    Process for the gas-phase homo- or copolymerization of alpha-olefin with
a pretreated catalyst system
    3.
    发明授权
    Process for the gas-phase homo- or copolymerization of alpha-olefin with a pretreated catalyst system 失效
    α-烯烃与预处理催化剂体系气相均聚或共聚的方法

    公开(公告)号:US5179180A

    公开(公告)日:1993-01-12

    申请号:US429025

    申请日:1989-10-30

    摘要: The polymerization of certain alpha-olefins in a gas phase involves the problem of agglomeration of the product into particles disadvantageous from the viewpoint of its handling. In the present invention this problem has been solved by means of a new type of process for the homo- or copolymerization of alpha-olefins. In the process the catalyst system is pretreated by contacting and reacting a transition-metal compound which is solid or on a solid carrier with an organoaluminum compound, and possibly an electron donor, in a liquid medium, and by drying the thus formed reaction product to produce a solid catalyst system. The thus pretreated solid and active catalyst system is then fed together with an alpha-olefin in the gaseous state into a gas-phase reactor, and polymerization is carried out by contacting them with each other. By feeding a dry and active catalyst system into the gas-phase reactor, it is possible to avoid the agglomeration of the product which occurs in conventional processes in which an organoaluminum compound and possibly an electron donor are fed in a liquid medium into the reactor.

    摘要翻译: 在气相中某些α-烯烃的聚合涉及从其处理的观点来看,不利于产物聚集成颗粒的问题。 在本发明中,这个问题已经通过用于α-烯烃均聚或共聚的新型方法来解决。 在该方法中,催化剂体系通过在液体介质中使固体或固体载体上的过渡金属化合物与有机铝化合物和可能的电子给体接触并使其反应,并将由此形成的反应产物干燥 产生固体催化剂体系。 然后将如此预处理的固体和活性催化剂体系与气态的α-烯烃一起进料到气相反应器中,并通过使它们彼此接触进行聚合。 通过将干燥和活性的催化剂体系进料到气相反应器中,可以避免在有机铝化合物和可能的电子给体在液体介质中进料到反应器中的常规方法中发生的产物的聚集。

    Method for homo- or copolymerizing ethene
    4.
    发明授权
    Method for homo- or copolymerizing ethene 失效
    乙烯均相或共聚方法

    公开(公告)号:US5391654A

    公开(公告)日:1995-02-21

    申请号:US66004

    申请日:1993-05-25

    摘要: The invention relates to a method for homo- or copolymerizing ethene in the presence of a Ziegler-Natta or other catalyst and a possible comonomer and hydrogen for preparing a homo- or copolymer of ethene in particle form in propane. In accordance with the invention, the polymerization is performed in a loop reactor under such supercritical conditions where the temperature is higher than the critical temperature of the mixture formed by ethene, propane and a possible hydrogen and a comonomer, but lower than the melting temperature of the ethene polymer forming in the polymerization, and the pressure is higher than the critical pressure of said mixture.

    摘要翻译: PCT No.PCT / FI91 / 00397 Sec。 371日期:1993年5月25日 102(e)日期1993年5月25日PCT 1991年12月18日PCT PCT。 公开号WO92 / 12181 日本1992年7月23日。本发明涉及在齐格勒 - 纳塔或其他催化剂和可能的共聚单体和氢气存在下均匀或共聚乙烯的方法,用于制备丙烷中颗粒形式的乙烯的均聚物或共聚物 。 根据本发明,聚合反应在环流反应器中在这样的超临界条件下进行,其中温度高于由乙烯,丙烷和可能的氢和共聚单体形成的混合物的临界温度,但低于熔融温度 聚合中形成的乙烯聚合物,并且压力高于所述混合物的临界压力。