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    42.
    发明专利
    未知

    公开(公告)号：DE59009828D1

    公开(公告)日：1995-12-07

    申请号：DE59009828

    申请日：1990-03-22

    Applicant: HOECHST AG

    Inventor： PEUCKERT MARCELLUS DR ,  VAAHS TILO DR ,  BRUECK MARTIN ,  KLEINER HANS-JERG DR ,  RIEDEL RALF DR ,  SEHER MARTIN ,  PETZOW GUENTER PROF DR

    IPC: C01B21/068 ,  C04B35/58 ,  C04B35/589 ,  C04B35/626

    Abstract: The invention relates to a novel sinterable ceramic powder, to its preparation and to its further processing to give a silicon nitride ceramic, and to this material itself and its use. The sinterable ceramic powder is produced by melting a polysilazane or dissolving it in an organic solvent, suspending a powdered sinter aid in this melt or solution, then pyrolyzing the melt, or the residue obtained after evaporation of the solvent, at 500 DEG to 1600 DEG C. in a protective gas atmosphere, the polysilazane either A) being obtainable by reacting at least one of the oligosilazanes of the formula (I) +TR in which a, b, c and d are the mole fractions of the respective structural units and where 0 in which R and R* can be identical or different and R and R* are C1-C4-alkyl, vinyl or phenyl and R' is C1-C4-alkyl and x and y are the mole fractions of the two structural units, where x+y=1 and x=0.7-0.95. A molded article can be formed from the ceramic powder thus obtained and a silicon nitride ceramic then produced by sintering. However, a molded article can also be formed from the solidified melt or the still unpyrolyzed residue obtained after evaporating the solvent and this article can then by pyrolyzed and sintered. Components subject to severe mechanical, thermal and corrosive stress can be produced from the ceramic obtained.

    44.
    发明专利
    未知

    公开(公告)号：DE59102315D1

    公开(公告)日：1994-09-01

    申请号：DE59102315

    申请日：1991-04-25

    Applicant: HOECHST AG

    Inventor： BRUECK MARTIN ,  VAAHS TILO DR ,  PEUCKERT MARCELLUS DR ,  SCHEUNEMANN UDE DR ,  STEHLIN THOMAS DR ,  THEIS JUERGEN DR

    IPC: C04B35/589 ,  C03C13/04 ,  C04B35/584 ,  C04B41/50 ,  C04B41/87 ,  D01F9/10 ,  D06M11/00 ,  D06M11/60 ,  D06M101/00 ,  G02B1/00

    Abstract: Method of making optical materials from silicon nitride by pyrolysis of polymeric silazanes by pressing, before the pyrolysis, the pulverulent polymeric silazanes to give mouldings or first dissolving the polymeric silazanes in an organic solvent, drawing fibres from this solution and pyrolysing said fibres after evaporation of the solvent or by melting of polymeric silazanes, casting, injection-moulding or extruding this melt to give mouldings and subsequent pyrolysis. During or after the pyrolysis, an oxidic layer is produced in an oxygen-containing atmosphere on the silicon nitride moulding. The pyrolysis can be carried out at 800-1000 DEG C in an atmosphere containing ammonia or containing ammonia/inert gas mixtures.

    45.
    发明专利
    未知

    公开(公告)号：DE58906898D1

    公开(公告)日：1994-03-17

    申请号：DE58906898

    申请日：1989-11-29

    Applicant: HOECHST AG

    Inventor： VAAHS TILO DR ,  PEUCKERT MARCELLUS DR ,  BRUECK MARTIN

    IPC: C04B35/58 ,  C04B35/589 ,  C08G77/48 ,  C08G77/60 ,  C08G77/62 ,  D01F9/10

    Abstract: The invention relates to novel polymeric ethylene-bridged chlorosilazanes, their preparation, their further processing to give silicon nitride containing ceramic material, and to this material itself. For the preparation of the polymeric chlorosilazanes, oligosilazanes of the formula (I) … … are reacted with at least one of the chlorosilanes … … R SiCl3 or R SiHCl2, where R to R are C1-C6-alkyl or C2-C6-alkenyl groups which can be identical or different. … The polymeric chlorosilazanes according to the invention can be converted by reaction with ammonia into polysilazanes which, in turn, can be pyrolysed to give silicon nitride-containing ceramic materials.

    Prodn. of boron-contg. poly:silane(s), useful for prodn. of ceramics - by reacting tris-chloro:silyl:ethyl-borane(s) with alkali metal(s)
    46.
    发明专利
    Prodn. of boron-contg. poly:silane(s), useful for prodn. of ceramics - by reacting tris-chloro:silyl:ethyl-borane(s) with alkali metal(s) 未知

    公开(公告)号：DE4320786A1

    公开(公告)日：1994-01-05

    申请号：DE4320786

    申请日：1993-06-23

    Applicant: HOECHST AG

    Inventor： RIEDEL RALF DR ,  KIENZLE ANDREAS DIPL CHEM ,  PETZOW GUENTER PROF DR ,  BRUECK MARTIN DIPL ING ,  VAAHS TILO DR

    IPC: C04B35/571 ,  C04B35/589 ,  C08G77/60 ,  D01F6/78 ,  D01F9/10 ,  C04B35/58

    Abstract: B-contg. polysilanes (II) are produed by reacting tris-silyl-borane(s) of formula B-(C2H4-SiCl2X)3 (I) with metallic Li, Na and/or K. In (I), -C2H4- is -CH2-CH2- or -CHMe-; and X is Cl or 1-4C aliphatic residue. In (II), R = 1-4C aliphatic residue; and a + b is 1. At least equimolar amts. of alkali metal are useed, and the reaction is carried out in organic solvent, by adding the other reactants at 50-120 deg. C and then heating at 60-200 deg. C, pref. with exposure to ultrasound. Pref. (I) are prepd., e.g. by reaction of corresp. vinylsilanes of formula CH2=CH-SiCl2X with BH3.THF as described in J. Organomet. Chem. 34 (1972) C9 and 135 (1977) 249, and in Zhur. Obshchei. Thim. 30 (1960) 3615. Suitable solvents are, e.g. heptane, toluene, THF etc. USE/ADVANTAGE - (II) are new B-contg. polysilanes, useful for the prodn. of B- and Si- contg. ceramics with good adhesion, hardness and surface quality, which are useful for coating steel etc., esp. for the surface coating of machine components which are subjected to mechanical and chemical stress. (II) can also be shaped before pyrolysis, e.g. to give ceramic fibres which are useful for reinforcement of Al, Al alloys and ceramic components. In an example, tris-((dichloromethylsilyl) ethyl)-borane (I) was prepd. by reacting 216g dichloromethylvinylsilane in 255 ml toluen with 255 ml 2M soln. of BH3.SM32 in toluene, followed by evapn. of solvent to give 233g (I). Refluxing suspension of Na/K alloy (obtd. by melting 2.83g Na with 10.05g K) in THF was treated slowly with 27.5g (I), under the action of ultrasound. Mixt. was then worked up by filtration and evapn. to give polymer (II), contg. (apporx.) 42.8 wt.% C, 8.4 wt.% H, 11.8 wt.% B, 32.1 wt.% Si, below 0.2 wt.% Cl. 2.5g (II) was pressed-moulded to form a cylinder which was pyrolysed by heating under N2 to 1200 deg. C at 1 deg./min. and maintaining this temp. for a further 3 hrs. Black ceramic prod. obtd. showed slight shrinkage but no evidence of melting; X-ray diffraction analysis showed no crystalline phases.

    49.
    发明专利
    未知

    公开(公告)号：DE4013306A1

    公开(公告)日：1991-10-31

    申请号：DE4013306

    申请日：1990-04-26

    Applicant: HOECHST AG

    Inventor： BRUECK MARTIN ,  VAAHS TILO DR ,  PEUCKERT MARCELLUS DR ,  SCHEUNEMANN UDE DR ,  STEHLIN THOMAS DR ,  THEIS JUERGEN DR

    IPC: C04B35/589 ,  C03C13/04 ,  C04B35/584 ,  C04B41/50 ,  C04B41/87 ,  D01F9/10 ,  D06M11/00 ,  D06M11/60 ,  D06M101/00 ,  G02B1/00

    Abstract: Method of making optical materials from silicon nitride by pyrolysis of polymeric silazanes by pressing, before the pyrolysis, the pulverulent polymeric silazanes to give mouldings or first dissolving the polymeric silazanes in an organic solvent, drawing fibres from this solution and pyrolysing said fibres after evaporation of the solvent or by melting of polymeric silazanes, casting, injection-moulding or extruding this melt to give mouldings and subsequent pyrolysis. During or after the pyrolysis, an oxidic layer is produced in an oxygen-containing atmosphere on the silicon nitride moulding. The pyrolysis can be carried out at 800-1000 DEG C in an atmosphere containing ammonia or containing ammonia/inert gas mixtures.

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