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22 条记录 (耗时 0.027 秒)

    Preparation of substantially polycrystalline silicon carbide fibers from polyorganosiloxanes
    2.
    发明授权
    Preparation of substantially polycrystalline silicon carbide fibers from polyorganosiloxanes 失效
    从聚有机硅氧烷制备基本上多晶碳化硅纤维

    公开(公告)号：US5167881A

    公开(公告)日：1992-12-01

    申请号：US649315

    申请日：1991-01-31

    申请人： William H. Atwell ,  Duane R. Bujalski ,  Eric J. Joffre ,  Gary E. LeGrow ,  Jonathan Lipowitz ,  James A. Rabe

    发明人： William H. Atwell ,  Duane R. Bujalski ,  Eric J. Joffre ,  Gary E. LeGrow ,  Jonathan Lipowitz ,  James A. Rabe

    IPC分类号： C04B35/571

    CPC分类号： C04B35/571

    摘要： A process for the preparation of substantially polycrystalline silicon carbide fibers are provided. The fibers may be fabricated to have a small diameter and are thermally stable at high temperature. The process is carried out by initially forming fibers from a preceramic polymeric precursor comprising phenyl-containing polyorganosiloxane resins. The fibers are then infusibilized to render them nonmelting followed by a pyrolysis step in which the fibers are heated to a temperature in excess of 1600.degree. C. in a nonoxidizing atmosphere to form substantially polycrystalline silicon carbide fibers. The substantially polycrystalline silicon carbide fibers which are formed have at least 75% crystallinity and have a density of at least about 2.9 gm/cm.sup.3. The polymeric precursor or the fibers contain, or have incorporated therein, at least about 0.2 % by weight boron. This incorporation of boron may be accomplished either prior to or during formation of the fibers or during at least one of the infusibilizing or pyrolyzing steps of the process.

    摘要翻译： 提供了制备基本上多晶碳化硅纤维的方法。 纤维可以制造成具有小直径并且在高温下是热稳定的。 该方法通过初始形成来自包含含苯基的聚有机硅氧烷树脂的陶瓷前体聚合物前体的纤维进行。 然后将纤维熔融以使其不熔化，随后进行热解步骤，其中将纤维在非氧化气氛中加热至超过1600℃的温度以形成基本上多晶的碳化硅纤维。 形成的基本上多晶的碳化硅纤维具有至少75％的结晶度并且具有至少约2.9gm / cm 3的密度。 聚合物前体或纤维含有至少约0.2重量％的硼或其中并入其中。 这种硼的掺入可以在纤维形成之前或期间或在该方法的至少一个不熔化或热解步骤期间完成。

    Method for densification of amorphous ceramic material
    4.
    发明授权
    Method for densification of amorphous ceramic material 失效
    非晶陶瓷材料致密化方法

    公开(公告)号：US5135809A

    公开(公告)日：1992-08-04

    申请号：US577165

    申请日：1989-09-27

    申请人： James A. Rabe ,  Jonathan Lipowitz ,  Richard E. Jones

    发明人： James A. Rabe ,  Jonathan Lipowitz ,  Richard E. Jones

    IPC分类号： C04B35/571 ,  C04B35/575 ,  C04B35/589 ,  C04B35/593

    CPC分类号： C04B35/5755 ,  C04B35/571 ,  C04B35/589 ,  C04B35/5935 ,  Y10S428/902 ,  Y10T428/2913 ,  Y10T428/2918 ,  Y10T428/2927 ,  Y10T428/2975

    摘要： The elastic modulus and density of an amorphous, ceramic article derived from a resinous organosilicon polymer and having a composition consisting essentially of silicon, nitrogen and/or carbon are increased while substantially maintaining or improving tensile strength by heat treating the ceramic article at an elevated temperature under superatmospheric nitrogen pressure to increase its density while avoiding crystallization. During heat treatment, at least some of the conditions of time, temperature, heating rate, cooling rate, pressure and atmosphere are controlled to minimize erosion of the article which could otherwise occur due to the loss to the surrounding atmosphere, as a gas or gaseous component, of at least one of nitrogen, silicon and carbon. The heat treated, ceramic article is amorphous and non-crystalline and has a density substantially greater than 2.5 g/cc together with desirable values of tensile strength and elastic modulus.

    摘要翻译： 衍生自树脂状有机硅聚合物并且具有基本上由硅，氮和/或碳组成的组成的无定形陶瓷制品的弹性模量和密度增加，同时通过在高温下热处理陶瓷制品而基本上保持或改善拉伸强度 在超大气压氮气压力下增加其密度，同时避免结晶。 在热处理期间，控制时间，温度，加热速率，冷却速度，压力和气氛的至少一些条件，以最小化由于对周围大气的损失而产生的制品的侵蚀，作为气体或气体 组分，氮，硅和碳中的至少一种。 热处理的陶瓷制品是无定形和非结晶的，并且具有基本上大于2.5g / cc的密度以及所需的拉伸强度和弹性模量值。

    Method of producing silicon carbide preceramic vinyl-containing polymers
    6.
    发明授权
    Method of producing silicon carbide preceramic vinyl-containing polymers 失效
    生产碳化硅前陶瓷含乙烯基聚合物的方法

    公开(公告)号：US4824918A

    公开(公告)日：1989-04-25

    申请号：US93434

    申请日：1987-09-04

    申请人： Duane R. Bujalski ,  Gary E. LeGrow ,  Jonathan Lipowitz ,  Thomas F. Lim

    发明人： Duane R. Bujalski ,  Gary E. LeGrow ,  Jonathan Lipowitz ,  Thomas F. Lim

    IPC分类号： C08G77/20 ,  C04B35/571 ,  C08F2/48 ,  C08G77/06 ,  C08G77/22 ,  C08G77/48 ,  C08G77/60 ,  C08F283/00

    CPC分类号： C04B35/571 ,  C08G77/60

    摘要： Vinyl-containing polysilanes are described wherein the vinyl groups are attached to endblocking sites of intermediate reactivity. These vinyl-containing polysilanes are prepared by reacting a halogen-endblocked polysilane with, first, a non-vinyl-containing Grignard reagent or a non-vinyl organolithium compound whereby the most reactive halogen endblocking groups are replaced; then, second, reacting the resulting polysilane with vinyl Grignard reagent or vinyllithium whereby the halogen endblocking groups of intermediate reactivity are replaced; and, third, reacting the resulting polysilane with a non-vinyl-containing Grignard reagent or a non-vinyl organolithium compound whereby the least reactive halogen endblocking groups are replaced. The vinyl-containing polysilanes can be coverted to ceramic materials, including ceramic fibers, by pyrolysis.

    摘要翻译： 描述含乙烯基聚硅烷，其中乙烯基连接到中间反应性的封端部位。 这些含乙烯基的聚硅烷通过使卤素封端的聚硅烷与首先是含有非乙烯基的格氏试剂或非乙烯基有机锂化合物反应制备，由此更换最活泼的卤素封端基团; 然后，使所得聚硅烷与乙烯基格氏试剂或乙烯基锂反应，由此更换中间反应性的卤素封端基团; 第三，使得到的聚硅烷与非乙烯基格氏试剂或非乙烯基有机锂化合物反应，由此更换最少的反应性卤素封端基团。 含乙烯基的聚硅烷可通过热解覆盖陶瓷材料，包括陶瓷纤维。

    Process to produce silicon carbide fibers using a controlled concentration of boron oxide vapor
    7.
    发明授权
    Process to produce silicon carbide fibers using a controlled concentration of boron oxide vapor 失效
    使用受控浓度的氧化硼蒸气生产碳化硅纤维的方法

    公开(公告)号：US06261509B1

    公开(公告)日：2001-07-17

    申请号：US09541666

    申请日：2000-04-03

    申请人： Thomas Duncan Barnard ,  Jonathan Lipowitz ,  Kimmai Thi Nguyen

    发明人： Thomas Duncan Barnard ,  Jonathan Lipowitz ,  Kimmai Thi Nguyen

    IPC分类号： B28B100

    CPC分类号： C04B35/62272 ,  C04B35/571

    摘要： A process for producing polycrystalline silicon carbide by heating an amorphous ceramic fiber that contains silicon and carbon in an environment containing boron oxide vapor. The boron oxide vapor is produced in situ by the reaction of a boron containing material such as boron carbide and an oxidizing agent such as carbon dioxide, and the amount of boron oxide vapor can be controlled by varying the amount and rate of addition of the oxidizing agent.

    摘要翻译： 一种通过在含有氧化硼蒸汽的环境中加热含有硅和碳的无定形陶瓷纤维来生产多晶碳化硅的方法。 通过含硼材料如碳化硼和二氧化碳等氧化剂的反应，原位产生氧化硼蒸汽，氧化硼蒸汽的量可以通过改变氧化剂的添加量和加入量来控制 代理商

    Method of polymerizing hydroxyl endblocked polydiorganosiloxane using quaternary ammonium carboxylate-carboxylic acid catalyst
    10.
    发明授权
    Method of polymerizing hydroxyl endblocked polydiorganosiloxane using quaternary ammonium carboxylate-carboxylic acid catalyst 失效
    使用羧酸羧酸羧酸羧酸催化剂聚合羟基封端的聚二有机硅氧烷的方法

    公开(公告)号：US4486567A

    公开(公告)日：1984-12-04

    申请号：US474917

    申请日：1983-03-14

    申请人： Sheryl A. Bowman ,  James R. Falender ,  Jonathan Lipowitz ,  John C. Saam

    发明人： Sheryl A. Bowman ,  James R. Falender ,  Jonathan Lipowitz ,  John C. Saam

    IPC分类号： C08L83/00 ,  C08G77/00 ,  C08G77/08 ,  C08G77/22 ,  C08K5/09 ,  C08K5/19 ,  C08L83/04 ,  C08L83/06

    CPC分类号： C08K5/09 ,  C08G77/08 ,  C08K5/19

    摘要： Hydroxyl-endblocked polydiorganosiloxane oligomer is polymerized through the use of a catalyst mixture of quaternary ammonium carboxylate and carboxylic acid. The method heats the mixture of oligomer and catalyst to a temperature in the range of from 90.degree. C. to 150.degree. C., removing water from the mixture, until the desired degree of condensation is achieved. When cooled, the product is a stable polydiorganosiloxane of increased molecular weight. The catalyst can be inactivated by heating and removing volatile byproducts. One embodiment of the method adds an acidic or neutral reinforcing filler to the mixture before polymerization to yield a storage stable silicone polymer-filler mixture which is useful in a manner similar to conventionally produced silicone polymer-filler mixtures.

    摘要翻译： 羟基封端的聚二有机硅氧烷低聚物通过使用羧酸季铵和羧酸的催化剂混合物而聚合。 该方法将低聚物和催化剂的混合物加热至90℃至150℃的温度，从混合物中除去水，直至达到所需的冷凝程度。 当冷却时，产物是分子量增加的稳定的聚二有机硅氧烷。 催化剂可以通过加热和除去挥发性副产物来灭活。 该方法的一个实施方案是在聚合之前向混合物中加入酸性或中性增强填料，得到储存稳定的硅氧烷聚合物 - 填料混合物，其以类似于常规制备的硅氧烷聚合物 - 填料混合物的方式是有用的。