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    2.
    发明专利
    未知

    公开(公告)号：DE3909978A1

    公开(公告)日：1990-09-27

    申请号：DE3909978

    申请日：1989-03-25

    Applicant: HOECHST AG

    Inventor： PEUCKERT MARCELLUS DR ,  VAAHS TILO DR ,  BRUECK MARTIN ,  KLEINER HANSS-JERG DR ,  RIEDEL RALF DR ,  SEHER MARTIN ,  PETZOW GUENTHER 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.

    3.
    发明专利
    未知

    公开(公告)号：DE3840775A1

    公开(公告)日：1990-06-07

    申请号：DE3840775

    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 ,  C08G77/62 ,  D01F9/10

    Abstract: The polymeric chlorosilazanes are prepared by reacting a mixture of oligosilazanes of the formula (I) … … in which n is from about 2 to about 12, and oligosilazanes of the formula (II) (RSiHNH)m in which m is from about 3 to about 12, with at least one of the chlorosilanes Cl2R Si-CH2-CH2-SiR Cl2, Cl3Si-CH2-CH2-SiR Cl2, R SiCl3 or R SiHCl2 at from 30 DEG C to 300 DEG C, where R and R to R are C1-C6-alkyl or C2-C6-alkenyl groups, which may be identical or different. … The polymeric chlorosilazanes according to the invention can be reacted with ammonia to give polysilazanes, which can themselves be pyrolysed to give silicon nitride-containing ceramic materials.

    6.
    发明专利
    未知

    公开(公告)号：DE58908181D1

    公开(公告)日：1994-09-15

    申请号：DE58908181

    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 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.

    7.
    发明专利
    未知

    公开(公告)号：DE3939448A1

    公开(公告)日：1990-06-07

    申请号：DE3939448

    申请日：1989-11-29

    Applicant: HOECHST AG

    Inventor： PEUCKERT MARCELLUS DR ,  BRUECK MARTIN DIPL ING ,  VAAHS TILO DR ,  KLEINER HANSS-JERG DR ,  ALDINGER FRITZ DR

    IPC: C04B35/58 ,  C04B35/589 ,  C04B35/593 ,  C04B41/50 ,  C04B41/84 ,  C04B41/87

    Abstract: The invention relates to a high-strength ceramic composite, in particular made from silicon nitride, a process for its preparation and its use. The process comprises impregnating an open-pore matrix with a molten polysilazane in a first step and, in a second step, heating the impregnated matrix to 800 DEG to 2500 DEG C. under a blanketing gas, such as nitrogen or a noble gas, or to 800 DEG to 1500 DEG C. under a gas containing ammonia. The high-strength ceramic composite prepared can be used as a component to be subjected to high thermal, mechanical or corrosive stress.

    9.
    发明专利
    未知

    公开(公告)号：DE3840770A1

    公开(公告)日：1990-06-07

    申请号：DE3840770

    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 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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