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    12.
    发明专利
    未知

    公开(公告)号：DE58901767D1

    公开(公告)日：1992-08-06

    申请号：DE58901767

    申请日：1989-07-15

    Applicant: HOECHST AG

    Inventor： GERDAU THOMAS DR ,  KLEINER HANS-JERG DR ,  BRUECK MARTIN ,  PEUCKERT MARCELLUS DR ,  ALDINGER FRITZ DR

    IPC: C01B21/068 ,  C04B35/58 ,  C04B35/589 ,  C08G77/48 ,  C08G77/62 ,  C08L83/16 ,  D01F9/10

    Abstract: The invention relates to a process for the production of ceramic material containing silicon nitride, such as fibers, coatings or moldings. In this process, polymeric hydridochlorosilazanes are rendered infusible at a temperature below their softening point by treatment with gaseous NH3 and are then pyrolyzed in an atmosphere containing NH3 at 700 DEG to 1500 DEG C. Fibers, coatings or moldings containing silicon nitride are produced by first producing appropriate structures from a melt of the polymeric hydridochlorosilazane and then rendering them infusible and pyrolyzing them.

    19.
    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.

    20.
    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.

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