Branched Low and Medium Density Polyethylene
    73.
    发明申请
    Branched Low and Medium Density Polyethylene 审中-公开
    支链中低密度聚乙烯

    公开(公告)号:US20110172322A1

    公开(公告)日:2011-07-14

    申请号:US12296966

    申请日:2007-04-13

    Abstract: The invention relates to a long chain branched medium and low density polyethylene having a combination of the following properties: a) a density of from 0.910 to 0.945 g/cm3; b) an HLMI of from 2 to 150 dg/min and an MI2 of from 0.01 to 2 dg/min; c) a polydispersity index (PDI) Mw/Mn of at least 7, wherein Mw is the weight average molecular weight and Mn is the number average molecular weight of the polyethylene; and d) and a minimum amount of long chain branching measured by a value selected from one of grheo and LCBI. The invention also relates to a process for obtaining said polyethylene comprising the following steps: a) injecting ethylene, one or more alpha-olefinic comonomers comprising 3 to 10 carbon atoms and an activated chromium-based catalyst into a gas phase polymerisation reactor; b) copolymerising said ethylene and comonomer in said reactor in the gas phase; and c) retrieving an ethylene copolymer having a density of from 0.910 to 0.945 g/cm3 from said reactor; said activated catalyst having a chromium concentration of at least 0.1 wt-% and of at most 1.0 wt-% based on the weight of the titanated chromium-based catalyst and a titanium concentration of from 1 wt-% to 5 wt-% based on the weight of the titanated chromium-based catalyst, whereby the catalyst was titanated with vaporised titanium compound and activated at a temperature of at least 500° C.

    Abstract translation: 本发明涉及具有以下特性的组合的长链支化介质和低密度聚乙烯:a)0.910至0.945g / cm 3的密度; b)HLMI为2至150dg / min,MI2为0.01至2dg / min; c)多分散指数(PDI)Mw / Mn至少为7,其中Mw是重均分子量,Mn是聚乙烯的数均分子量; 和d)和通过选自格莱和LCBI之一的值测量的最小量的长链分支。 本发明还涉及一种获得所述聚乙烯的方法,包括以下步骤:a)将乙烯,一种或多种含有3至10个碳原子的α-烯烃共聚单体和活化的铬基催化剂注入气相聚合反应器中; b)在气相中在所述反应器中共聚所述乙烯和共聚单体; 和c)从所述反应器中回收密度为0.910至0.945g / cm 3的乙烯共聚物; 所述活化催化剂的铬浓度基于钛酸化铬基催化剂的重量为至少0.1重量%至多1.0重量%,钛浓度为1重量%至5重量%,基于 钛酸铬催化剂的重量,由此催化剂用蒸发的钛化合物钛化并在至少500℃的温度下活化

    Copolymers and films thereof
    74.
    发明授权
    Copolymers and films thereof 有权
    共聚物及其膜

    公开(公告)号:US07968659B2

    公开(公告)日:2011-06-28

    申请号:US11883162

    申请日:2006-01-27

    Inventor: Choon Kooi Chai

    Abstract: Copolymers of ethylene and an alpha-olefin having (a) a density in the range 0.900-0.940 g/cm3, (b) a molecular weight distribution (Mw/Mn) in the range 3.5 to 4.5, (c) a melt elastic modulus G′ (G″=500 Pa) in the range 40 to 150 Pa, (d) an activation energy of flow (Ea) in the range 28-45 kJ/mol, and (e) a melt index (g/10 ml) in the range 1.0-3.5. The copolymers are suitably prepared in the gas phase by use of a supported metallocene catalyst system. The copolymers show improved processability and are particular suitable for use in blown film applications.

    Abstract translation: (a)密度在0.900-0.940g / cm3范围内的乙烯和α-烯烃的共聚物,(b)分子量分布(Mw / Mn)在3.5至4.5的范围内,(c)熔体弹性模量 G'(G“= 500Pa),(d)流动活化能(Ea)在28-45kJ / mol的范围内,(e)熔体指数(g / )在1.0-3.5范围内。 共聚物通过使用负载的茂金属催化剂体系在气相中合适地制备。 共聚物显示出改善的加工性,并且特别适用于吹塑薄膜应用。

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