Ethylene enhancement of processes for synthesis of high melting
theromoplastic elastomeric .alpha.-olefin polymers (PRE/EPE effects)
    3.
    发明授权
    Ethylene enhancement of processes for synthesis of high melting theromoplastic elastomeric .alpha.-olefin polymers (PRE/EPE effects) 失效
    合成高熔点弹性体α-烯烃聚合物的方法的乙烯增强(PRE / EPE效应)

    公开(公告)号:US6160064A

    公开(公告)日:2000-12-12

    申请号:US97234

    申请日:1998-06-12

    摘要: This invention relates generally to low ethylene insertions into .alpha.-olefin polymers and processes for production of such polymers using unbridged fluxional metallocenes, primarily substituted aryl indenyl metallocenes, and more particularly to use of unbridged, fluxional, cyclopentadienyl or indenyl metallocene catalyst systems in methods of production of high melting point .alpha.-olefin homo- and co-polymers, particularly elastomeric crystalline and amorphous block homo- and co-polymers of .alpha.-olefins. The activity of fluxional unbridged metallocene polymerization catalysts containing at least one 2-arylindene ligand is increased 10.times. or more by the addition of small (typically 0.1-10 wt. %) amounts of ethylene to the polymerization system, which increase is termed the Polymerization Rate-Enhancement effect (PRE), which is measured in terms of an Ethylene Enhancement Factor (EEF) as a dimensionless ratio in the range of from about 1.1 to about 10 or above. A second important aspect of this invention is the ability to use a PRE activity-enhancing amount of ethylene in an olefin polymerization without substantially affecting the physical properties of the elastomer. In a third important aspect of this invention, .alpha.-olefin elastomers are produced through incorporation of ethylene using unbridged fluxional catalyst systems which may not otherwise produce acceptable elastomeric homopolymers. Preferred polymers of this invention retain sufficient crystallinity to provide a high melting point (by DSC) of about 80.degree. C., preferably above 100.degree. C., including in the range of from about 120.degree. C. to about 140.degree. C. and above. Novel flexible .alpha.-olefin homo and copolymers having elongation in excess of 600% and substantially no retained force are disclosed.

    摘要翻译: 本发明一般涉及低乙烯插入α-烯烃聚合物和使用未桥联的流动金属茂(主要是取代的芳基茚基金属茂)制备这种聚合物的方法,更具体地说,涉及使用未桥联的,流动的,环戊二烯基或茚基茂金属催化剂体系 生产高熔点α-烯烃均聚物和共聚物,特别是α-烯烃的弹性体结晶和无定形嵌段均聚物和共聚物。 含有至少一个2-芳基茚配体的流动非桥联茂金属聚合催化剂的活性通过向聚合体系中加入少量(通常0.1-10重量%)的乙烯而增加10倍或更多,这种增加称为聚合速率 - 增强效应(PRE),其以乙烯增强因子(EEF)测量为无量纲比,其范围为约1.1至约10或更高。 本发明的第二个重要方面是在烯烃聚合中使用PRE活性增加量的乙烯的能力,而基本上不影响弹性体的物理性能。 在本发明的第三个重要方面,α-烯烃弹性体是通过使用未经简化的流动催化剂体系引入乙烯制备的,其可能不能产生可接受的弹性体均聚物。 本发明优选的聚合物保持足够的结晶度以提供约80℃,优选高于100℃的高熔点(通过DSC),包括在约120℃至约140℃的范围内,以及 以上。 公开了具有超过600%的伸长率和基本上没有保持力的新型柔性α-烯烃均聚物和共聚物。

    Production of high pore volume alumina spheres
    4.
    发明授权
    Production of high pore volume alumina spheres 失效
    生产高孔体积的氧化铝球体

    公开(公告)号:US4140773A

    公开(公告)日:1979-02-20

    申请号:US880830

    申请日:1978-02-24

    IPC分类号: C01F7/36 C01F7/02

    摘要: High macro-pore content spheres (>1000A) are produced by use of a rotating wheel, wherein dry alumina is dropped onto the wheel under a peptizing spray misted onto the wheel through an atomizing device. Compressive stresses normally encountered in procedures such as pelletizing are avoided, thereby preserving macro-pores. Size of spheres can be adjusted by altering, for example, the angle at which the wheel rotates.

    摘要翻译: 通过使用旋转轮产生高的大孔含量球体(> 1000A),其中干燥氧化铝通过雾化装置在雾化喷雾下方落在轮上。 避免在诸如造粒的过程中通常遇到的压缩应力,从而保留大孔。 可以通过改变例如车轮旋转的角度来调节球体的尺寸。

    High pore volume alumina powders
    10.
    发明授权
    High pore volume alumina powders 失效
    高孔体积氧化铝粉末

    公开(公告)号:US4218413A

    公开(公告)日:1980-08-19

    申请号:US970282

    申请日:1978-12-18

    摘要: A method for increasing the pore volume of alumina powder produced by spray drying alumina slurries by heating the slurry to a temperature near the boiling point of water and a pressure up to the critical point of water then introducing the slurry to a spray drying chamber through a small orifice, thereby creating a backpressure in excess of slurry vapor pressure and up to the critical point of water.

    摘要翻译: 通过将浆料加热到接近水沸点的温度并将压力升至水的临界点,从而通过喷雾干燥氧化铝浆料产生的氧化铝粉末的孔体积增加的方法,然后将浆料通过 从而产生超过浆料蒸汽压力并高达临界点的背压。