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    31.
    发明专利
    未知

    公开(公告)号：DE3840777A1

    公开(公告)日：1990-06-07

    申请号：DE3840777

    申请日：1988-12-03

    Applicant: HOECHST AG

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

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

    Abstract: The invention relates to novel chlorine-containing silazane polymers, to their preparation, their further processing to ceramic material containing silicon nitride, and this material itself. In order to prepare the chlorine-containing silazane polymers, oligosilazanes of the formula (I) in which a>0, b>/=0 and n is about 2 to about 12, are reacted with at least one of the chlorosilanes Cl2R4Si-CH2-CH2-SiR4Cl2, Cl3Si-CH2-CH2-Sir5Cl2, R6SiCl3 or R7SiHCl2 at 30 DEG C. to 300 DEG C., where, independently of one another, R1 and R2=H, C1-C6-alkyl or C2-C6-alkenyl, R3, R4, R5, R6 and R7=C1-C6-alkyl or C2-C6-alkenyl and where if b=0 the reaction with R7SiHCl2, if R7=C1-C6-alkyl and none of the other chlorosilanes is present, is to be excluded. The chlorine-containing silazane polymers according to the invention can be converted by reaction with ammonia into polysilazanes, which in their turn can be pyrolyzed to form ceramic materials containing silicon nitride.

    32.
    发明专利
    未知

    公开(公告)号：DE3840173A1

    公开(公告)日：1990-05-31

    申请号：DE3840173

    申请日：1988-11-29

    Applicant: HOECHST AG

    Inventor： PEUCKERT MARCELLUS DR

    IPC: C04B35/58 ,  C04B35/584

    Abstract: The invention relates to a silicon nitride ceramic having a high strength both at low temperatures and at temperatures above 1000 DEG C., and to a process for its preparation. The silicon nitride ceramic contains, as the primary phase, beta -silicon nitride and, as a crystalline secondary phase, an yttrium compound which has been caused to crystallize out from the intergranular glass phase by thermal after-treatment. Teh yttrium-containing, crystalline secondary phase has the following d-values in an X-ray diffraction pattern using Cu-K alpha radiation: 4.69 &cir& ; 4.05 &cir& ; 3.48 &cir& ; 3.20 &cir& ; 3.06 &cir& ; 2.81 &cir& ; 2.40 &cir& ; 2.07 &cir& ; 2.03 &cir& ; and 1.87 &cir& , the most intense diffraction reflection having the d-value 3.06 &cir& +/-0.01 &cir& . A residue of amorphous glass phase is present in the ceramic as a further phase between the crystal grains.

    33.
    发明专利
    未知

    公开(公告)号：DE3840171A1

    公开(公告)日：1990-05-31

    申请号：DE3840171

    申请日：1988-11-29

    Applicant: HOECHST AG

    Inventor： PEUCKERT MARCELLUS DR

    IPC: C04B35/58 ,  C04B35/584

    Abstract: The invention concerns a high-strength multi-phase silicon nitride ceramic material, characterized in that the ceramic material contains as a primary phase at least 80 % by wt. of rod-crystalline beta -silicon nitride, as a secondary, crystalline phase, homogeneously distributed between the silicon nitride rods, 1-5 % by wt. of cubic titanium nitride, and as the remainder less than 15 % by wt. of an intergranular glass phase containing the elements silicon, aluminium, cerium, oxygen and nitrogen, plus, optionally, traces of titanium. The silicon nitride ceramic material is produced by sintering powder mixtures of alpha -silicon nitride, cerium oxide, aluminium oxide and titanium oxide and/or preferably aluminium titanate.

    37.
    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.

    38.
    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.

    39.
    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.

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