Method for the preparation of silicon carbide whiskers
    3.
    发明授权
    Method for the preparation of silicon carbide whiskers 失效
    碳化硅晶须的制备方法

    公开(公告)号:US4981666A

    公开(公告)日:1991-01-01

    申请号:US931667

    申请日:1986-11-17

    IPC分类号: C30B29/62 C30B25/00

    CPC分类号: C30B25/005 C30B29/36

    摘要: In place of the conventional silicon source materials used in the prior art method for the preparation of silicon carbide whiskers, the inventive method utilizes a hydrolysis product of a chlorosilane compound R.sub.a SiCl.sub.4-a or a chlorodisilane compound R.sub.b Si.sub.2 Cl.sub.6-b, in which R is a hydrogen atom or a monovalent hydrocarbon group, a is zero to 3 and b is 1 to 5, as the silicon source which is intimately mixed with a powder of carbon and the mixture is heated at 1400.degree. to 1700.degree. C. to give silicon carbide whiskers in a high conversion. Alternatively, the hydrolysis of the chloro(di)silane compound is performed in an aqueous medium in which a powder of carbon is dispersed in advance so that the hydrolysis product as formed is already a mixture with the carbon powder.

    摘要翻译: 本发明方法代替用于制备碳化硅晶须的现有技术方法中使用的常规硅源材料,其利用氯硅烷化合物RaSiCl4-a或氯二硅烷化合物RbSi2Cl6-b的水解产物,其中R为氢 原子或一价烃基,a为0〜3,b为1〜5,作为与碳粉充分混合的硅源,将混合物在1400〜1700℃下加热,得到碳化硅晶须 在高转换。 或者,氯(二)硅烷化合物的水解在预先分散有碳粉末的水性介质中进行,使得形成的水解产物已经是与碳粉末的混合物。

    Method for the preparation of a sintered body of silicon carbide
    4.
    发明授权
    Method for the preparation of a sintered body of silicon carbide 失效
    制备碳化硅烧结体的方法

    公开(公告)号:US4762810A

    公开(公告)日:1988-08-09

    申请号:US17818

    申请日:1987-02-24

    CPC分类号: C04B35/571

    摘要: Sintered bodies of silicon carbide having remarkably increased volume resistivity and thermal conductivity can be obtained by heating a green body shaped of a fine silicon carbide powder admixed with boron or a boron compound, e.g. boron carbide, titanium boride and boron oxide, as a sintering aid at 1800.degree. to 2200.degree. C. in the presence of or in the vicinity of a shaped body of a powdery mixture of a fine silicon carbide powder admixed with boron nitride in the same furnace. The improvements in the volume resistivity and thermal conductivity of the sintered body are particularly remarkable when the fine silicon carbide powder is a pyrolysis product of a methyl hydrogen silane compound such as tetramethyl disilane.

    摘要翻译: 可以通过加热与硼或硼化合物混合的细小碳化硅粉末的生坯体,例如通过加热形成具有显着增加的体积电阻率和导热性的碳化硅的烧结体。 碳化硼,硼化钛和氧化硼作为烧结助剂,在1800-2200℃下,在与其相同的氮化硼混合的细碳化硅粉末的粉末混合物的成形体存在下或其附近 炉。 当细碳化硅粉末是甲基氢硅烷化合物如四甲基乙硅烷的热解产物时,烧结体的体积电阻率和热导率的改善是特别显着的。

    Method for preparing hexamethyl cyclotrisilazane
    5.
    发明授权
    Method for preparing hexamethyl cyclotrisilazane 失效
    制备十六烷基环己烷的方法

    公开(公告)号:US5075474A

    公开(公告)日:1991-12-24

    申请号:US679199

    申请日:1991-04-02

    IPC分类号: B01J31/02 C07F7/10 C07F7/21

    CPC分类号: C07F7/21

    摘要: According to the method for preparing hexamethyl cyclotrisilazane of the present invention, hexamethyl cyclotrisilazane can be obtained by heating a linear or cyclic silazane compound represented by the following general formula:--(Me.sub.2 SiNH).sub.n --(wherein Me represents a methyl group and n is an integer of not less than 4) in the presence of at least one catalytic compound selected from the group consisting of ammonium salts of arylsulfonic acids and/or aminoarylsulfonic acids and the resulting hexamethyl cyclotrisilazane represented by the formula: --Me.sub.2 SiNH).sub.3 -- can be recovered by distilling off the same outside the reaction system. According to the method of the present invention, highly pure hexamethyl cyclotrisilazane can be industrially prepared in good efficiency and in a high yield. In particular, if octamethyl cyclotetrasilazane which can be industrially prepared from cheap dimethyldichlorosilane is used as a starting material, hexamethyl cyclotrisilazane can also be prepared at a low cost. Thus, the method of the present invention has enough practical value in the organic silicon industries.

    Method for the preparation of a sintered body of silicon carbide
    6.
    发明授权
    Method for the preparation of a sintered body of silicon carbide 失效
    制备碳化硅烧结体的方法

    公开(公告)号:US5011639A

    公开(公告)日:1991-04-30

    申请号:US453038

    申请日:1989-12-12

    CPC分类号: H01L21/4807 C04B35/565

    摘要: A powdery mixture of a fine silicon carbide powder admixed with boron or a boron compound, e.g. boron carbide, titanium boride and boron oxide, as a sintering aid is compression-molded into a green body which is subjected to a sintering treatment into a sintered body. Different from conventional methods in which the sintering treatment is performed always in an atmosphere of an inert gas, e.g. argon, the sintering treatment in the inventive method is performed in an atmosphere of a rare gas containing 0.005-5% by volume of nitrogen. The sintered body of silicon carbide obtained by this method has an outstandingly high electric volume resistivity of 10.sup.10 to 10.sup.13 ohm.cm and a coefficient of thermal conductivity of 100-220 W/m.K.

    摘要翻译: 与硼或硼化合物混合的细碳化硅粉末的粉末混合物,例如 作为烧结助剂的碳化硼,硼化钛和氧化硼被压缩成型坯,其经历烧结处理成烧结体。 不同于常规方法,其中始终在惰性气体气氛中进行烧结处理,例如, 氩气中,本发明方法中的烧结处理在含有0.005-5体积%氮气的稀有气体的气氛中进行。 通过该方法获得的碳化硅烧结体具有极高的体积电阻率为1010至1013欧姆·厘米,导热系数为100-220W / m·K。

    Process for the preparation of a polycarbodiimide solution
    9.
    发明授权
    Process for the preparation of a polycarbodiimide solution 失效
    制备聚碳二亚胺溶液的方法

    公开(公告)号:US5750637A

    公开(公告)日:1998-05-12

    申请号:US658166

    申请日:1996-06-04

    CPC分类号: C08G73/00 C08G18/025

    摘要: This invention provides a process for the preparation of a polycarbodiimide solution wherein the polycarbodiimide is synthesized by heating an organic diisocyanate (e.g., 2,4-tolylene diisocyanate or 2,6-tolylene diisocyanate) in the presence of a carbodiimidation catlayst characterized in that a non-chlorinated aromatic hydrocarbon is used as the solvent and the resulting polycarbodiimide has a number average molecular weight from about 3,000 to about 10,000; wherein the synthesis is performed in the temperature range of from about 100.degree. to about 120.degree. C.

    摘要翻译: 本发明提供一种制备聚碳二亚胺溶液的方法,其中聚碳二亚胺通过在碳二亚胺二酰亚胺存在下加热有机二异氰酸酯(例如,2,4-甲苯二异氰酸酯或2,6-甲苯二异氰酸酯)来合成,其特征在于, 使用非氯化芳烃作为溶剂,所得聚碳二亚胺的数均分子量为约3,000至约10,000; 其中合成在约100℃至约120℃的温度范围内进行。

    Process for manufacturing organic silazane polymers and ceramics
therefrom
    10.
    发明授权
    Process for manufacturing organic silazane polymers and ceramics therefrom 失效
    从其制造有机硅氮烷聚合物和陶瓷的方法

    公开(公告)号:US4869854A

    公开(公告)日:1989-09-26

    申请号:US114111

    申请日:1987-10-27

    摘要: A process for manufacturing an organic silazane polymer which comprises reacting ammonia with a mixture of at least one compound selected from the group consisting of organic silicon compounds of the following formulae (I) and (II) ##STR1## and at least one compound selected from the group consisting of organic silicon compounds of the following formula (III) ##STR2## in which R represents hydrogen, chlorine, bromine, methyl radical, ethyl radical, phenyl radical or vinyl radical, R.sub.1 represents hydrogen or methyl radical, R.sub.2 represents hydrogen, methyl radical, ethyl radical, phenyl radical or vinyl radical and X represents chlorine or bromine; to obtain an ammonolysis product. The ammonolysis product is polymerized in the presence of a basic catalyst capable of deprotonation to obtain an organic silazane polymer. The silazane polymer may be further melted, shaped and infusibilized. The thus infusibilized product is finally sintered to obtain a ceramic material.

    摘要翻译: 一种制备有机硅氮烷聚合物的方法,其包括使氨与至少一种选自下式(I)和(II)的有机硅化合物的化合物的混合物反应:(IMA) II)和选自下式(III)的有机硅化合物(III)中的至少一种化合物,其中R表示氢,氯,溴,甲基,乙基,苯基或乙烯基 R1表示氢或甲基,R2表示氢,甲基,乙基,苯基或乙烯基,X表示氯或溴; 以获得氨解产物。 氨解产物在能够去质子化的碱性催化剂存在下聚合,得到有机硅氮烷聚合物。 硅氮烷聚合物可以进一步熔融,成型和不熔化。 将这样的不熔化产物最终烧结得到陶瓷材料。