Abstract: The present invention relates to a plastic comprising zinc sulphide and to its use.

Abstract: Disclosed herein is a silicon adhesive composition for transporting a flexible substrate. The composition includes (A) 42 to 70 parts by weight of a polydiorganosiloxane containing an alkenyl group, (B) 55 to 28 parts by weight of a polyorganosiloxane copolymer including R13SiO1/2 units and SiO2 units, wherein R1 is a hydroxy group or a monovalent hydrocarbon group of 1 to 12 carbon atoms, (C) a polyorganosiloxane containing an SiH group, wherein the molar ratio of the SiH group of component (C) to the alkenyl group of component (A) is from 0.5 to 20, and (D) a platinum group catalytic compound, wherein the weight ratio of a metal component of the compound to the sum of components (A) and (B) is from 1 to 5000 ppm by weight.

Abstract: The reaction of halo-boron compounds (B—X compounds, compounds having one or more boron-halogen bonds) with silanes provides boranes (B—H compounds, compounds having one or more B—H bonds) and halosilanes. Inorganic hydrides, such as surface-bound silane hydrides (Si—H) react with B—X compounds to form B—H compounds and surface-bound halosilanes. The surface bound halosilanes are converted back to surface-bound silanes electrochemically. Halo-boron compounds react with stannanes (tin compounds having a Sn—H bond) to form boranes and halostannanes (tin compounds having a Sn—X bond). The halostannanes are converted back to stannanes electrochemically or by the thermolysis of Sn-formate compounds. When the halo-boron compound is BCl3, the B—H compound is B2H6, and where the reducing potential is provided electrochemically or by the thermolysis of formate.

Abstract: An addition-curable silicone composition is provided. The composition includes (A) a resin structure organopolysiloxane and (B) a platinum group metal-based catalyst. The component (A) has silicon-bonded alkenyl groups and hydrosilyl groups, and includes a structure in which R22SiO units, wherein R2 is a methyl group, etc., are connected together in a continuous repeating sequence, and the number of units in the continuous repeating sequence is within a range from 5 to 300. The composition can be prepared in a solid or semisolid form, and hence is suitable conventional molding apparatus such as a transfer molding apparatus, and upon curing, forms a hard resin cured product that exhibits excellent flexibility and minimal surface tack.

Abstract: There are provided a sheet having a silicon/plastic bi-layer structure capable of easily transferring a paste even when a hard roll is used, the hard roll having excellent durability but having disadvantages that the paste is poorly transferred when the paste is printed on a plastic base, and a method for producing the same. The bi-layer structured sheet having excellent printability when printed by hard roll includes a flexible substrate and a silicon resin formed on the substrate.

Abstract: A fluoropolymer composition comprising monomers copolymerized in the following percentages by weight: (a) from about 20% to about 95% of a fluoroalkyl monomer, or mixture of monomers, of formula (I) Rf1-L-X—C(O)—C(R)?CH2 ??(I) wherein Rf1 is a monovalent, partially or fully fluorinated, linear or branched, alkyl radical having from about 2 to about 100 carbon atoms; optionally interrupted by 1 to about 50 oxygen atoms; wherein the ratio of carbon atoms to oxygen atoms is at least about 2:1 and no oxygen atoms are bonded to each other; L is a linear or branched divalent linking group having 1 to about 20 carbon atoms; optionally interrupted by 1 to about 4 hetero-radicals selected from the group consisting or —O—, —NR1—, —S—, —SO—, —SO2—, —N(R1)C(O)—; wherein R1 is H or C1 to C6 alkyl; X is —O—, —NR1—, or —S—; R is hydrogen, Cl, F or CH3; (b) from about 5% to about 80% of at least one of: (i) an alkyl(meth)acrylate monomer having a linear, branched or cyclic alkyl group of from about 6 to about 1

Abstract: [Problems to be Solved] To provide a curable organopolysiloxane composition, wherein the composition can be laminated directly on the surface of an epoxy resin anticorrosive coating film and can form an antifouling coating film which has improved antifouling performance compared to the conventional art. [Means for Solving the Problems] A two-liquid type or three-liquid type curable organopolysiloxane composition, wherein the composition contains at least an organopolysiloxane having at least two condensation reactive groups in the molecule (a1), silica (a2), an organosilane and/or a partial hydrolyzate thereof (b1), wherein the organosilane has functional group(s) capable of undergoing condensation reaction with the condensation reactive groups of the above organopolysiloxane (a1), and at least one kind of tin compound selected from the group represented by a predefined general formula.

Abstract: A hydrosilylation-curable silicone resin composition having a melting point of 50° C. or higher and a melt viscosity at 150° C. of 5,000 mPa·s or higher, comprising a fine thermoplastic resin powder that contains a platinum-type catalyst; is a solid in a powdered form at room temperature, melts when heated, is suitable for transfer and injection molding, and is suitable for molding into a cured body that possesses high strength and is not subject to change of color under the effect of heat or ultraviolet radiation.

Abstract: The invention relates to a method of preparing a particle-based composition, comprising: (i) bringing into contact a mixture comprising a dendritic structure and a metal compound precursor in a fluid, under temperature and pressure conditions such that the mixture is not soluble in the fluid; and (ii) chemically converting the metal compound precursor.

Abstract: Process for production of post-crosslinkable thermoplastic resins by bulk-polymerizing a polymerizable composition (A) comprising (I) a monomer fluid containing a cyclic olefin (?) having two or more metathetical ring-opening reaction sites in the molecule in an amount 10 wt % or above based on the total amount of the monomers or a monomer fluid containing a norbornene monomer and a crosslinking agent, (II) a metathetical polymerization catalyst, and (III) a chain transfer agent; thermoplastic resins obtained by this process. These thermoplastic resins are free from odor due to residual monomers and are excellent in storage stability. Process for producing crosslinked resins and composite materials which comprises laminating the thermoplastic resin to a substrate and then crosslinking the thermoplastic resin.

Abstract: An organic/inorganic composite including a condensation product of an organic silicon compound represented by formula (I) as a major component; at least one kind of a photosensitive compound which is sensitive to light having a wavelength of 350 nm or less selected from the group consisting of metal chelate compounds, compounds of metal organic acid salts, metal compounds having 2 or more hydroxyl or hydrolyzable groups, hydrolyzates thereof, and condensation products thereof; and/or a compound derived from the photosensitive compound; RnSiX4-n??(I) wherein R represents an organic group in which carbon directly bonds to Si represented in the formula and X represents a hydroxyl or hydrolyzable group; n represents 1 or 2; R may be the same or different when n is 2; and X may be the same or different when (4-n) is 2 or more.

Abstract: A two-liquid composition, includes (A) a first liquid composition that contains a hydrophilic polymer having a hydrolyzable silyl group; and (B) a second liquid composition that contains a catalyst capable of accelerating reaction of the hydrolyzable silyl group, and a hydrophilic member is formed by mixing the first liquid composition (A) and the second liquid composition (B), coating a substrate with the resultant mixture and drying the mixture coated.

Abstract: An aqueous coating material composition, includes: a hydrophilic polymer that has a hydrophilic group-containing structural unit and at least one hydrolyzable silyl group represented by formula (a) in a main chain terminal or side chain of the hydrophilic polymer, wherein the hydrophilic group-containing structural unit is contained in an amount of 30 mol % or more based on the entire hydrophilic polymer: —Si(R102)a—(OR101)3-a??Formula (a) wherein R101 represents a hydrogen atom or an allyl group; R102 represents a hydrogen atom or a monovalent hydrocarbon group selected from the group consisting of an alkyl group, an aryl group and an aralkyl group; a represents an integer of 0 to 2; and when a plurality of R101's or R102's are present, the plurality of R101's or R102's may be the same or different respectively.

Abstract: Vinyl-terminated organopolysiloxanes also having pendant allyl functionality exhibit high cure rates with low extractables, while exhibiting superior release properties when compared to higher alkenyl functionality.

Abstract: A curable silicone composition containing an organopolysiloxane that contains in one molecule at least one epoxy-containing organic group, has a polystyrene-referenced weight-average molecular weight at least 500, and is expressed by the following general unit formula: (RSiO3/2)x[R1aSiO(4-a)/2]y (where R represents a cycloalkyl group, and R1 represents hydrogen atom or a univalent organic group, except for an aromatic group and a cycloalkyl group, at least one R1 in one molecule being an epoxy-containing univalent organic group, and where the following condition is observed: 0<a?3; x>0; y>0; and x+y=1).

Abstract: [Problems] There is provided a curable composition having good adhesion by using a non-organotin catalyst. [Means to Solve Problems] The curable composition comprises (A) an organic polymer having a silicon-containing group being capable of crosslinking by forming siloxane bonds and (B) one or more kinds selected from a titanium catalyst, an aluminum catalyst and a zirconium catalyst, and is characterized in that a stress at 50% tension is within a range from 0.01 MPa to 0.20 MPa, when determined by adding and mixing 1.5 parts of tin octylate, 0.25 part by weight of laurylamine and 0.6 part by weight of pure water to 100 parts by weight of the component (A), subjecting the mixture to centrifugal defoaming, pouring the mixture carefully into a polyethylene frame not to mix air bubbles thereto, aging the mixture at 23° C. for one hour, and further at 70° C. for 20 hours, punching the obtained 3 mm thick cured sheet according to JIS K6251 to obtain No.

Abstract: An antistatic agent useful for mixing with thermoplastic polymers is disclosed which comprises a reaction product of an inorganic pigment, more typically TiO2; optionally at least one silane; and a siloxane compound.

Abstract: A coating composition includes (A) a thermally-decomposing polymer selected from a thermally-decomposing polymer (1) and a thermally-decomposing polymer (2); and (B) an alkoxide compound of an element selected from Si, Ti, Zr and Al, wherein the thermally-decomposing polymer (1) has a structural unit represented by the following general formula (I-a) and a structural unit represented by the following general formula (I-b), and the thermally-decomposing polymer (2) has a structural unit represented by the following general formula (II-b) and has a functional group represented by the following general formula (II-a) at the terminal of the polymer chain: wherein the symbols in the formulae are defined in the specification.

Abstract: Self-polymerization of mono-aziridine (or azetidine) and multi-aziridine (or azetidine) containing compounds with vinyl group containing organic acid, such as acrylic acid (AA), 2-methylenesuccinic acid, 2,3-dimethylenesuccinic acid and etc, at ambient temperature results in the new type of cross-linked and linear type copolymers, respectively. The polymerization of multi-functional aziridine (or azetidine) containing compounds with vinyl group containing organic acid results in the formation of high cross-linked polymers. The self-polymerization takes place at ambient temperature and the resultants, cross-linked polymeric networked materials, are solvent insoluble and potential for adhesive, composite matrix and other applications. These insoluble materials are hydrolyzed in an acidic or basic condition to form the water soluble ?-amino acids.

Abstract: A composition comprising at least one fluorochemical polyether silane compound having a polyfluoropolyether segment and at least two hydrolysable silane groups per molecule, one or more non-fluorinated compounds having at least two hydrolysable groups per molecule, and/or a partial condensate thereof, is disclosed. The composition provides durable water, oil and stain repellency to a substrate.

Abstract: A composition including a non-silicone material, a silicone material, and a crosslinking agent. The composition forms a structure selected from the group consisting of an interpenetrating network structure and a thermoplastic vulcanizate structure.

Abstract: A novel adhesive cures quickly at a lower temperature and ensures reliable connection of objects the adhesive connects with each other. The adhesive includes a metal chelate, a silane coupling agent and a thermosetting resin. The silane coupling agent in the adhesive is hydrolyzed at its alkoxy groups to form silanol groups, which in turn react with the metal chelate to produce cations in the adhesive. The resulting cations cause the epoxy resin as a thermosetting resin, to undergo cationic polymerization. The adhesive of the present invention cures at a lower temperature by taking advantage of the cationic polymerization.

Abstract: A thermoset polymer has a repeating unit comprising at least one crosslinking group having at least one unsaturated carbon-carbon bond and at least two crosslinking bonds, at least one borate group, at least one silyl group and/or at least one siloxyl group. The thermoset polymer of the present invention may be prepared by reacting a first compound having at least one alkynyl group, and at least one group selected from silyl groups and siloxyl groups, with a second compound selected from boric acid, hydrocarbon boronic acid, hydrocarbon borate, and pyroboric acid under reaction conditions sufficient to crosslink a sufficient number of alkyne bonds to form the thermoset polymer. The thermoset polymer of the present invention possesses both the processability of an organic polymer and the thermal and oxidative stability of an inorganic polymer. The thermoset polymer of the present invention may be further processed into a ceramic material by pyrolysis.

Abstract: The invention provides a high molecular weight silicone compound comprising recurring units of formula (1) and having a weight average molecular weight of 1,000-50,000. Some or all of the hydrogen atoms of carboxyl groups or carboxyl and hydroxyl groups in the silicone compound may be replaced by acid labile groups. Z is a di- to hexavalent, non-aromatic, monocyclic or polycyclic hydrocarbon or bridged cyclic hydrocarbon group; Z is a di- to hexavalent, normal or branched hydrocarbon group or non-aromatic, monocyclic or polycyclic hydrocarbon or bridged cyclic hydrocarbon group; x, y and z are integers of 1-5 corresponding to the valence of Z and Z′; R1 is —OCHR—R′—OH or —NHCHR—R′—OH; R2 is alkyl or alkenyl or a monovalent, non-aromatic, polycyclic hydrocarbon or bridged cyclic hydrocarbon group; p1, p2, p3 and p4 are 0 or positive numbers.

Abstract: A composition comprising a least one fluorochemical polyether silane compound having a polyfluoropolyether segment and at least two hydrolysable silane groups per molecule, one or more non-fluorinated compounds having at least two hydrolysable groups per molecule, and/or a partial condensate thereof, is disclosed. The composition provides durable water, oil and stain repellency to a substrate.

Abstract: Disclosed are silicone polymer based compounds, which include a hydrophobic silicone polymer backbone and a hydrophilic component. The hydrophilic component may act as a chelating agent to bind a metal. The hydrophilic component may be hydrophilic prior to binding with a metal or after binding. Also disclosed are methods of making these compounds. The compounds are useful in a variety of applications.

Abstract: The present invention provides to an organo-bridged ladderlike polysiloxane having the following formula: and a tube-like organosilicon polymer, complexes thereof and the method for producing the same.

Abstract: The invention provides a high molecular weight silicone compound comprising recurring units of formula (1) and having a weight average molecular weight of 1,000-50,000. Some or all of the hydrogen atoms of carboxyl groups or carboxyl and hydroxyl groups in the silicone compound may be replaced by acid labile groups.

Abstract: A composition of matter, comprising: a chemically functionalized carboxylate-alumoxane that is functionalized with a chemically reactive substituent, and a reactive compound, wherein the chemically reactive substituent reacts with the reactive compound so as to link the carboxylate-alumoxane to the reactive compound and form a polymer matrix. The functional groups on the carboxylate-alumoxane can vary depending on the desired properties of the matrix. Also, the composition of matter may comprise a cross-linked matrix in which the cross-linked components consist of functionalized alumoxanes.

Abstract: A coating liquid for forming a transparent coating, comprising fine particles of an inorganic compound, and a hydrolyzate of an organosilicon compound represented by the general formula (I):

Abstract: The invention provides a high molecular weight silicone compound comprising recurring units of formula (1) and having a weight average molecular weight of 1,000-50,000. Some or all of the hydrogen atoms of carboxyl groups or carboxyl and hydroxyl groups in the silicone compound may be replaced by acid labile groups. Z is di- to hexavalent, non-aromatic, monocyclic or polycyclic hydrocarbon or bridged cyclic hydrocarbon group; Z′ is a di- to hexavalent, normal or branched hydrocarbon group or non-aromatic, monocyclic or polycyclic hydrocarbon or bridged cyclic hydrocarbon group; x, y and z are integers of 1-5 corresponding to the valence of Z and Z′; R1 is —OCHR—R′ —OH or —NHCHR—R′ —OH; R2 is alkyl or alkenyl or a monovalent, non-aromatic, polycyclic hydrocarbon or bridged cyclic hydrocarbon group; p1, p2, p3 and p4 are 0 or positive numbers.

Abstract: The invention relates to novel organosiloxanyl derivatives of the general formula: to a process for preparing these derivatives, to the use thereof for preparing organomodified siloxanes and to the use thereof as paint additives.

Abstract: The addition-crosslinking silicone rubber compositions which crosslink to give a silicone rubber of increased heat resistance comprising a palladium-containing heat stabilizer.

Abstract: Macroporous, strong-acid polysiloxane ion exchange resins which have been converted to the silver or mercury form are utilized to remove iodides from non-aqueous organic media. In a particularly preferred method, hexyl iodide is removed from acetic acid.

Abstract: A group fo liquid crystalline compounds defined by formulas (1) and (2) including polymers, monomers, oligomers and intermediates for their preparation. Also included are symmetric and non-symmetric poly(dimethylsiloxy) compounds having end groups derived from Formulas (1) and (2).

Abstract: A coating composition comprising (A) a fluorine-containing polymer, (B) a compound represented by the following general formula (1) or a partial condensation product thereof,SiR.sup.1.sub.n (OR.sup.2).sub.4-n (1)wherein R.sup.1 represents an alkyl group, an aryl group, an aralkyl group, a group containing --SH, or a group containing --NCO, each containing 1 to 10 carbon atoms, R.sup.2 represents a hydrogen atom, an alkyl group or acyl group having 1 to 10 carbon atoms, and n is an integer from 0 to 3, and (C) a chelate complex derived from a metal alkoxide. The coating composition can efficiently form a transparent cured coating exhibiting superior adhesion to various substrates, excellent scratch resistance, excellent weatherability, and having a low refractive index.

Abstract: Group 4 metal-containing organosilicon dendrimers are described. Also described are methods for synthesizing the dendrimers. The dendrimers can be useful in several applications including as olefin polymerization and copolymerization catalysts and as silane polymerization catalysts.

Abstract: Adhesive room temperature vulcanizing silicone rubber compositions based on polydiorganosiloxanes, which cross-link by means of condensation are good adhesives. The compounds contain, in addition to the conventional components, the combination of at least one hydrolyzable alkylsilalne and at least one branched polysiloxane.

Abstract: A soft or rigid gas permeable silicon elastomer contact lens bonded with either titanium, titanium monoxide, titanium dioxide, dititanium trioxide, trititanium pentoxide, and mixtures thereof to form contact lens having high oxygen permeability, improved wetting ability, decreased fogging ability, an enhanced self-cleaning characteristic, and decreased transmissibility to ultraviolet radiation. Preferred methods of incorporating the additives is by cationic polymerization of either a coating of or in situ bonding to a silicon polymer resulting in the expression of the additive toward the exterior surface of the chemical matrix of the contact lens. Other bonding methods are electron beam evaporation., sputtering and ion implantation of the titanium additive.

Abstract: A composition curable in presence of atmospheric moisture to an elastomeric body, comprising (A) the product formed by mixing a polymeric material having at least two groups bonded to silicon which are hydroxyl or alkoxy group and an alkoxysilane curative and (B) a titanium compound according to the general formula Ti(OR).sub.x (OR').sub.y (OR*).sub.z where x is 0 to 0.4 inclusive, y is 0 to 3.9, z is 0.1 to 4, x+y+z=4, R* is 2,4-dimethyl-3-pentyl, R' represents a monovalent tertiary aliphatic hydrocarbon group, and JR represents a monovalent linear aliphatic hydrocarbon group having 1 to 6 carbon atoms. The compositions cure quickly and do not yellow.

Abstract: An adhesive composition based on a combination of a water soluble amino silane and a normally water-immiscible alkenyl-functional silane wherein the latter is hydrolyzed in the presence of the former under specified conditions to form a stable, water-dilutable aqueous composition having marked bonding affinity between polymers and solid substrates.

Abstract: Low temperature ductile and impact resistant compositions are provided which comprise a polycarbonate resin and a dual graft multi-stage polyorganosiloxane/polyvinyl-based graft polymer composition. Also provided are thermally stabilized multi-stage polyorganosiloxane/polyvinyl-based graft polymers which have improved color-imparting and impact resistance-imparting properties and thermoplastic compositions containing the same.

Abstract: Dental inorganic-organic composite fillers are disclosed, which do not scatter a visible light of from 360 to 830 nm in the particles thereof, has a refractive index nD by the D-line of sodium in the range of 1.460.ltoreq.nD.ltoreq.1.600, and which is represented by the following mean empirical formula:aM.sup.1 O.sub.x/2 .multidot.bSiO.sub.2 .multidot.cM.sup.2 O.sub.(4-i-j)/2 R.sup.1.sub.i R.sup.2.sub.jwhereinM.sup.1 is one or more members selected from Ti, Zr, Y, La, Ta, and Al, which is bonded to Si or M2 via the crosslinked oxygen; and x is a valence of M.sup.1 ;M.sup.2 is Si and/or Ti;R.sup.1 is a non-functional group; and R.sup.2 is an organic compound reacted with an organic functional group;i is 0, 1, or 2; and j is 1, 2, or 3, provided that i and j are satisfied with 1.ltoreq.(i+j).ltoreq.3; anda, b, and c are each a molar ratio, provided that a, b, and c are satisfied with 0.ltoreq.a/(a+b).ltoreq.0.65 and 0.02.ltoreq.c/(a+b).ltoreq.3.0.

Abstract: A method for forming dense ceramics, particularly a ceramic coating by a low temperature treatment is provided. The method for forming ceramics according to the invention is characterized in that a polysilazane having a number-average molecular weight of 100 to 50,000 or a modified polysilazane thereof is subjected to a heat treatment, then exposed to an atmosphere containing water vapor or immersed in distilled water containing a catalyst, or both, or is brought into contact with Pd.sup.2+ ions and water, the polysilazane having a skeleton comprising the unit represented by the following general formula (I): ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, a group other than the above and having a carbon atom directly attached to the silicon atom, an alkylsilyl group, an alkylamino group and an alkoxy group; with the proviso that at least one of R.sub.1, R.sup.2 and R.sup.3 is a hydrogen atom.

Abstract: The invention is a practical process for anionically synthesizing commercially significant quantities of macrocyclic polymers from polar and/or non-polar monomers by using Group IIA and IIB metal cyclic organometallic initiators. Activation of the ring metal atom results in anionic polymerization of the monomers by addition into the initiator ring at the bonds between the atom and its two adjacent carbon atoms, the metal atom acting as a bridge between the two living ends of the propagating chain. Coupling of the cyclic polymer living ends by coupling agents produces macrocyclic polymers that are stable in air and moisture and that exhibit desirable properties, such as low viscosities at high molecular weights. Such macrocyclic polymers provide enhanced polymer processability during molding, extruding and the forming of films.

Abstract: A method of making an organopolysiloxane sheet or tube polymer involves contacting a sheet or tube silicate with an organo-H-chlorosilane to form an organosiloxane sheet or tube polymer with pendent .tbd.Si--H groups. Subsequently, the organosiloxane sheet or tube polymer with pendent .tbd.Si--H groups is contacted with an alkenyl group containing compound in the presence of a hydrosilation catalyst. The catalyst is used in an amount effective to catalyze a hydrosilation reaction between the alkenyl group on the alkenyl group containing compound and the hydride functionality on the organosiloxane sheet or tube polymer with pendent .tbd.

Abstract: Organopolysiloxane sheet or tube polymers are made by contacting a sheet or tube silicate with an alkenyl group containing chlorosilane to form an alkenylsiloxy polymer, and subsequently contacting the alkenylsiloxy sheet or tube polymer with a hydrosilane or hydrosiloxane in the presence of a hydrosilation catalyst, to catalyze a reaction between the alkenyl group on the alkenylsiloxy polymer and hydride functionality on the hydrosilane or hydrosiloxane. Silylalkoxysiloxane sheet or tube polymers are made by contacting a sheet or tube silicate with an acidic solution of an alkenyl alcohol to form a polymeric sheet or tube alkenyloxysiloxane, and subsequently contacting the alkenyloxysiloxane with a hydrosilane or hydrosiloxane in the presence of a hydrosilation catalyst, to catalyze a reaction between the alkenyl group on the alkenyloxysiloxane and hydride functionality on the hydrosilane or hydrosiloxane.

Abstract: Oxide thin films are deposited onto functionalized self-assembled monolayers (SAMs) which are bonded to various surfaces. The resulting oxide thin films have ordered, uniform densely packed crystalline structures.

Abstract: A polyorganosiloxane-type thermoplastic resin having excellent slidability, abrasion resistance, weatherability, impact strength, fatigue resistance and chemical resistance is disclosed. The thermoplastic resin comprises a graft copolymer (IV) obtained by graft-polymerizing at least one vinyl monomer (v) onto a modified polyorganosiloxane obtained by polymerizing 80 to 99.8% by weight of an organosiloxane (I) having the structural unit described thereinabove, 0.1 to 10% by weight of at least one graft crosslinking agent (II) containing an alkoxysilyl group, selected from the group consisting of a vinyl-type graft crosslinking agent, a mercapto-type graft crosslinking agent, an acryloyl-type crosslinking agent and a vinylphenyl-type crosslinking agent, and 0.1 to 10% by weight of a compound (III) having two alkoxysilyl groups, provided that (I)+(II)+(III)=100% by weight.

Abstract: A preceramic polymetalosilazane substantially free of Si-O groups is produced by reacting a polysilazane with a metal alkoxide in the presence of an alkylsilazane or alkylsilane. The preceramic polymer gives a high strength and heat resistant ceramic body which remains amorphous when calcined at 1,600.degree. C. for 10 hours in the atmosphere of nitrogen.