摘要:
An aluminum-nitrogen polymer is prepared by reacting an organic nitrile with a dialkylaluminum hydride to form an organoaluminum imine, and heating the imine to a temperature of 50.degree. to 200.degree. C. for at least 2 hours. The polymeric product can be subjected to an additional heat treatment to form a more highly cross-linked polymer. After either heat treatment the polymeric product can be further reacted with a primary amine or ammonia. The organoaluminum imine as well as the aminated or non-aminated polymers can be pyrolyzed to form an aluminum nitride-containing ceramic.
摘要:
A process for preparing metallopolysilanes, which comprises reacting at least one disilane of the general formulaR.sub.6-n Si.sub.2 (OR.sup.1).sub.n (I)in which R may be the same or different and is a hydrogen atom or a monovalent hydrocarbon radical, R.sup.1 is the same or different monovalent alkyl groups, and n is 2, 3, 4, 5 or 6, and optionally mixed with at least one compound of the general formulaR.sup.2.sub.4-m Si(OR.sup.4)m (II)in which R.sup.2 may be the same or different and is the same as R, R.sup.4 may be the same or different and is the same as R.sup.1, and m is 1, 2, 3 or 4, with at least one compound of the general formula(R.sup.5 O)[A(OR.sup.5).sub.a-2.sup.O].sub.x R.sup.5 (III)in which R.sup.5 may be the same or different and is the same as R.sup.1, A is a metal from group IIa, IIIa, IVa, Va, IIIb, IVb or Vb of the Periodic Table, x is an integer of from 1 to 1,000, and a represents the valency of A, in the presence of at least one compound of the general formulaMOR.sup.3 (IV)in which R.sup.3 is the same as R.sup.1, and M represents an alkali metal atom.
摘要:
Hybrid sol-gel materials comprise silicate sols cross-linked with linear polysilane, polygermane, or poly(silane-germane). The sol-gel materials are useful as optical identifiers in tagging and verification applications and, in a different aspect, as stable, visible light transparent non-linear optical materials. Methyl or phenyl silicones, polyaryl sulfides, polyaryl ethers, and rubbery polysilanes may be used in addition to the linear polysilane. The linear polymers cross-link with the sol to form a matrix having high optical transparency, resistance to thermooxidative aging, adherence to a variety of substrates, brittleness, and a resistance to cracking during thermal cycling.
摘要:
An energy polymerizable composition and process therefore, comprising a cationically polymerizable material and a catalytically effective amount of an ionic salt of an organometallic complex cation as polymerization initiator, said ionic salt of an organometallic complex cation being capable of adding an intermediate strengeth nucleophile or upon photolysis capable of liberating at least one coordination site, said metal in said organometallic complex cation being selected from elements of Periodic Groups IVB, VB, VIB, VIIB, and VIIIB are disclosed. Certain of the organometallic metallic polymerization initiators are novel cationic salts.
摘要:
Preceramic polymers are prepared by mixing an organosilicon oligomer or polymer containing a multiplicity of Si--H and/or Si--N functional groups with a borane in an organic solvent for a sufficient time for the reactants to react, wherein the molar ratio of the organosilicon polymer repeat unit to borane is 15 or less.
摘要:
This invention concerns monosubstituted dithiooxamides, and a preferred class comprises those wherein the substituent is such that the resulting dithiooxamide derivative is substantially nonvolatile at about room temperature. Preferred materials are those for which when the monosubstituent dithiooxamide is complexed with a transition metal cation, the resulting polymer is substantially a dark, i.e., preferably blue or blue-black color. Carbonless paper constructions involving use of N-(monosubstituted)dithiooxamides to advantage are described.
摘要:
A positive type fine resist pattern can be formed at a high sensitivity at a high precision by using, as a resist film for a di-layer resist, a mixture or alternating copolymer of a silicon-containing resin and a polysulfone.
摘要:
Crosslinked boron/nitrogen preceramic polymers are prepared by reacting (a) admixture of a trihalogenoborane A and a compound B containing at least one dihalogenated boron atom, with (b) an amino compound C containing at least one --NH.sub.2 group; the resulting polymers are facilely pyrolyzed into boron nitride ceramic materials.
摘要:
Silicon nitride based ceramic fibers containing Si, N, O and at least one metal M in amounts providing the atomic ratios N/Si of 0.3 to 3, O/Si of 0.0001 to 15 and M/Si of 0.001 to 5 and exhibiting an X-ray small angle scattering such that the ratio of the intensity of the small angle scattering of the fibers to that of air is 1 to 20. The ceramic fibers are produced by spinning of a polymetallosilazane into fibers and calcining the spun fibers and are useful as reinforcing fibers for composite artices having a metal or resin matrix.
摘要:
A process for preparing tractable preceramic precursors of Group IIIA metal/Group VA nonmetal compounds, such as BN, in which a first reactant containing a Group VA nonmetal to hydrogen bond, such as ammonia or an amine is reacted with a second reactant containing a Group IIIA metal to hydrogen bond, such as a metal hydride, in the presence of a metal catalyst that catalyzes dehydrocoupling of the bonds to form the precursor. Further reaction of the precursor in the presence of the catalyst forms oligomeric/polymeric forms of the precursor.