Abstract: Methods and apparatus for bonding an electrostatic chuck to a component of a substrate support are provided herein. In some embodiments, an adhesive for bonding components of a substrate support may include a matrix of silicon-based polymeric material having a filler dispersed therein. The silicon based polymeric material may be a polydimethylsiloxane (PDMS) structure having a molecular weight with a low molecular weight (LMW) content ? D3-D10 of less than about 500 ppm. In some embodiments, the filler may comprise between about 50 to about 70 percent by volume of the adhesive layer. In some embodiments, the filler may comprise particles of aluminum oxide (Al2O3), aluminum nitride (AlN), yttrium oxide (Y2O3), or combinations thereof. In some embodiments, the filler may comprise particles having a diameter of about 10 nanometers to about 10 microns.

Abstract: A curable composition comprises (a) at least one polyorganosiloxane, fluorinated polyorganosiloxane, or combination thereof comprising reactive silane functionality comprising at least two hydroxysilyl moieties; (b) at least one polyorganosiloxane, fluorinated polyorganosiloxane, or combination thereof comprising reactive silane functionality comprising at least two hydrosilyl moieties; and (c) at least one photoactivatable composition comprising at least one organoborate salt selected from tetraarylborate, triarylorganoborate, diaryldiorganoborate, and aryltriorganoborate salts (and combinations thereof) of at least one base selected from amidines, guanidines, phosphazenes, proazaphosphatranes, and combinations thereof; wherein at least one of the components (a) and (b) has an average reactive silane functionality of at least three.

Abstract: This invention relates to viscoelastic silicone rubber compositions that are the products of the reaction of: (a) a silanol-terminated polyorganosiloxane base; (b) a boron-containing crosslinking agent; and (c) a siloxane bond-forming crosslinking agent. In a viscoelastic silicone rubber composition of the invention some of the crosslinks, the siloxane crosslinks, are permanent and others of the crosslinks, the boron-containing crosslinks, are temporary. Because a fraction of its crosslinks can come apart and then reform, a viscoelastic silicone rubber composition of the invention can relax stress in response to strain and thus adapt to new shapes. The composition has sufficient permanent crosslinks, however, to establish a permanent equilibrium shape to which the composition will eventually return when not subject to any imposed stress.

Abstract: Silicone resins with a weight average molecular weight of at least 5000 g/mol and polydispersity of ?65 are prepared by hydrolyzing and condensing: (A) silicon-bonded alkoxylated and optionally hydroxylated silicone resin intermediate(s), (C) a basic or acidic catalyst or mixture thereof which is not completely self-neutralizing, (D) water, and (E) in the presence of an aliphatic carboxylic ester as the sole process solvent, with the provisos that I) alcohol eliminated in the reaction is removed from the reaction mixture by distillation, II) the catalyst (C) is deactivated by thermal treatment or neutralization, and III) a portion of (E) remains in the final product.

Abstract: The present invention relates to a curable organopolysiloxane composition, which comprises: (A) an organocyclosiloxane having alkenyl groups, represented by the following formula (I) wherein n=3 or 4; (B) a hydrosilicone resin of formula (II) (R1R2R3SiO1/2)M.(R4R5SiO2/2)D.(R6SiO3/2)T.

Abstract: A borosiloxane composition comprising a borosiloxane having an average of at least two alkenyl groups per molecule, an organosilicon compound having an average of at least two silicon-bonded hydrogen atoms per molecule, and a hydrosilylation catalyst; a borosiloxane adhesive comprising a cured product of at least one borosiloxane; and a coated substrate and a laminated substrate, each comprising the borosiloxane adhesive.

Abstract: Embodiments of the invention provide for methods of producing a composition comprising a crosslinkable silane-terminated polymer having at least one crosslinkable silyl group in each molecule. The method comprises providing a polymer having at least one unsaturated group and at least one alcoholic hydroxyl group in each molecule, adding to the polymer a compound having a hydrogen-silicon bond and a crosslinkable silyl group in each molecule and a hydrosilylation catalyst to thereby carry out a hydrosilylation reaction to form a composition comprising hydrosilylated polyoxyalkylene polymers, reacting the hydrosilylated polyoxyalkylene polymers with at least one isocyanate in the presence of a first tin-free catalyst to form an isocyanate reacted hydrosilylated polymer, and optionally reacting the isocyanate reacted hydrosilylated polymer with a polyol having a nominal functionality of at least 2 to form a polyol reacted crosslinkable silane-terminated polymer.

Abstract: Provided are a salt compound, cationic polymerization initiator and cationically polymerizable composition, which have a superior acid-generating capacity and high sensitivity, and are free from coloration. The salt compound is represented by the following general Formula (1): (wherein, R01 to R05 each independently represents a group selected from a hydrogen atom, a fluorine atom and —YR group, one of the R01 to R05 being a —YR group and at least two of the R01 to R05 being fluorine atoms; Y represents an oxygen atom or a sulfur atom; R represents a C1-C4 alkyl group; Ctp+ represents a p-valent cation, the p being 1 or 2; and n represents a coefficient required for maintaining electrical neutrality).

Abstract: This invention relates to viscoelastic silicone rubber compositions that are the products of the reaction of: (a) a silanol-terminated polyorganosiloxane base; (b) a boron-containing crosslinking agent; and (c) a siloxane bond-forming crosslinking agent. In a viscoelastic silicone rubber composition of the invention some of the crosslinks, the siloxane crosslinks, are permanent and others of the crosslinks, the boron-containing crosslinks, are temporary. Because a fraction of its crosslinks can come apart and then reform, a viscoelastic silicone rubber composition of the invention can relax stress in response to strain and thus adapt to new shapes. The composition has sufficient permanent crosslinks, however, to establish a permanent equilibrium shape to which the composition will eventually return when not subject to any imposed stress.

Abstract: Disclosed is a moisture-curing type curable resin composition containing: a curable resin intramolecularly having a silicon-containing functional group; and a Lewis acid or a complex of the Lewis acid as a curing catalyst, the Lewis acid being selected from the group consisting of metal halides and boron halides, which is rapidly cured at room temperature. The silicon-containing functional group is represented by general formula: —SiX1X2X3 or —SiR1X1 X2 (wherein, X1, X2 and X3 respectively represent a hydrolytic group and may be the same as or different from each other, and R1 represents a substituted or unsubstituted organic group having 1 to 20 carbons). If the silicon-containing functional group is —SiR1X1 X2, the curable resin further contains intramolecularly a polar component that is one of urethane, thiourethane, urea, thiourea, substituted urea, substituted thiourea, amide, and sulfide bonds, and hydroxyl, secondary amino and tertiary amino groups.

Abstract: A thermoset and method of making such by crosslinking a mixture of a polyhedral oligomeric silsesquioxane having pendent siloxane groups or unsaturated carbon bonds and a siloxylcarborane compound having unsaturated carbon bonds.

Abstract: A method of making a diluted polysiloxane containing polymer comprising the steps of: i) Preparing a polysiloxane containing polymer by the polycondensation of siloxane containing monomers and/or oligomers which comprise condensable groups in the presence of an organopolysiloxane and/or an organic based diluent material, a suitable catalyst and optionally an end-blocking agent; and ii) Where required quenching the polymerization process; wherein the diluent material is substantially retained within the resulting diluted organopolysiloxane.

Abstract: The invention relates to a method for producing cross-linkable formulations. In a first step of the method, at least one ?,?-difunctional organic polymer of formula (1) X-A-X (1) is converted into organyloxysilyl-terminated polymers P1, using organofunctional silanes of formula (2) Y—R—Si—(R1)m(—OR2)3m (2), in the presence of catalysts (A) selected from the group consisting of potassium, iron, indium, zinc, bismuth and copper compounds.

Abstract: The invention relates to coating agents, containing (A) at least 50 wt. %, (in relation to the content of non-volatile substances in said coating agent), of at least one compound (A1) and/or (A1?) comprising at least two reactive groups of formula (I): —X—SiR?x(OR?)3-x, in which R?=hydrogen, alkyl or cycloalkyl, whereby the carbon chain can be interrupted by non-adjacent oxygen, sulphur or NRa groups, Ra=alkyl, cycloalkyl, aryl or aralkyl, X=a linear and/or branched alkene or cycloalkene group comprising between 2 and 20 carbon atoms, R?=alkyl, cycloalkyl, aryl or aralkyl, whereby the carbon chain can be interrupted by non-adjacent oxygen, sulphur or NRa groups, and x=0 to 2, (B) a catalyst for cross-linking the —Si(OR?)3-x units, and (C) an organic solvent or a mixture of organic solvents.

Abstract: The invention provides a process for preparing SiOC-bonded polyorganosiloxanes by reacting, by processes known per se, hydroxyl-containing compounds with a stoichiometric excess of polyorganosiloxanes which contain —Si(H) units and are of the general formula (I) in the presence of one or more element compounds of main group III and/or of transition group 3 as a catalyst, wherein the reaction, on completion of conversion of the compounds containing hydroxyl groups, is continued until no further ?Si—H groups are detectable by gas volumetric means, and also the compounds prepared in this way and their use.

Abstract: The invention relates to a process for the preparation of SiOC-linked, linear polydimethylsiloxane-polyoxyalkylene block copolymers having (AB) repeat units, via reaction by methods known per se of polyetherdiols with a stoichiometric excess of ?,?-dihydropolydimethylsiloxanes, in the presence of one or more compounds of elements of main group 13 and/or of transition group 3 as catalyst, which comprises, after completed reaction of the alcohol component, continuing the reaction until no remaining ?Si(H) groups are detectable by a gas-volumetric method, and also to the compounds thus prepared, and to their use as surfactant additives for the production of polyurethane ether foams.

Abstract: A light-shielding paste which contains a thermoplastic resin and an inorganic member as essential components or which contains a thermosetting resin and an inorganic member as essential components is provided. A curable composition and light-shielding paste comprising the composition are provided which contains, as essential components, (A) an organic compound comprising an organic main chain containing at least two carbon-carbon double bonds reactive with a SiH group in each molecule, (B) a silicon compound having at least two SiH groups in each molecule, (C) a hydrosilylation catalyst, (D) a silane coupling agent and/or an epoxy group-containing compound, (E) a silanol condensation catalyst, and (F) an inorganic member. The curable composition can further contain (G) silica. Also provided is a method of forming a light-shielding resin layer on a LED package having an aperture comprising a bottom and sidewalls. The curable composition is excellent in light-shielding ability.

Abstract: A material composition, which is used as a liquid resist, includes a first component comprising a monomer portion and at least one cationically polymerizable functional group, and a crosslinker reactive with the first component and comprising at least three cationically polymerizable functional groups. The material composition also includes a cationic photoinitiator. Upon exposure to UV light, the material composition crosslinks via cure to form a cured resist film that is the reaction product of the first component, the crosslinker, and the cationic photoinitiator. An article includes a substrate layer and a resist layer formed on the substrate layer from the material composition.

Abstract: Disclosed is a moisture-curing type curable resin composition containing: a curable resin intramolecularly having a silicon-containing functional group; and a Lewis acid or a complex of the Lewis acid as a curing catalyst, the Lewis acid being selected from the group consisting of metal halides and boron halides, which is rapidly cured at room temperature. The silicon-containing functional group is represented by general formula: —SiX1X2X3 or —SiR1X1X2 (wherein, X1, X2 and X3 respectively represent a hydrolytic group and may be the same as or different from each other, and R1 represents a substituted or unsubstituted organic group having 1 to 20 carbons). If the silicon-containing functional group is —SiR1X1X2, the curable resin further contains intramolecularly a polar component that is one of urethane, thiourethane, urea, thiourea, substituted urea, substituted thiourea, amide, and sulfide bonds, and hydroxyl, secondary amino and tertiary amino groups.

Abstract: The present invention provides a novel photocurable composition containing an organic polymer having an epoxy group and/or oxetane group-containing silicon group at an end and a cationic photoinitiator. For example, the photocurable composition contains an organic polymer (A) having an epoxy group and/or oxetane group-containing silicon group at an end, and a cationic photoinitiator (B), the organic polymer (A) being produced by addition reaction between an organic polymer terminated with an unsaturated group and a hydrosilane compound having an epoxy group and/or an oxetane group.

Abstract: The invention provides a process for preparing SiOC-bonded polyorganosiloxanes by reacting, by processes known per se, hydroxyl-containing compounds with a stoichiometric excess of polyorganosiloxanes which contain —Si(H) units and are of the general formula (I) in the presence of one or more element compounds of main group III and/or of transition group 3 as a catalyst, wherein the reaction, on completion of conversion of the compounds containing hydroxyl groups, is continued until no further ?Si—H groups are detectable by gas volumetric means, and also the compounds prepared in this way and their use.

Abstract: The present invention provides a curable composition providing a curing product having excellent adhesive properties and high transparency, or a curing product having high toughness and transparency. A curable composition which contains (A) an organic compound containing at least two carbon-carbon double bonds reactive with a SiH group in each molecule, (B) a silicon compound having at least two SiH groups in each molecule, (C) a hydrosilylation catalyst, (D) a silane coupling agent and/or an epoxy group-containing compound, and (E) a silanol condensation catalyst. A light-emitting diode sealed with a curing product obtainable by curing said curable composition.

Abstract: A new silicone condensation reaction, the condensation between an alkoxy silane or siloxane or a dihydric phenol and an organo-hydrosilane or siloxane and catalysts therefore is described and claimed.

Abstract: A novel organosiloxane polymer is obtained by addition reaction of an organohydrogenpolysiloxane, an alkenyl-containing organopolysiloxane and an unsaturated compound of formula (3) or (4). Using the organosiloxane polymer, a photo-curable resin composition is prepared which can be exposed to radiation having a wide range of wavelength and developed to form a pattern.

Abstract: The present invention relates to silicone-based dental compositions based on a functionalized silicone crosslinkable and/or polymerizable by heat-process. These novel dental compositions are polymerizable and/or crosslinkable in an oral environment, have markedly improved qualities, in particular as regards the very marked reduction in the phenomenon of shrinkage of the materials and prostheses obtained from said compositions. These novel dental compositions are particularly advantageous in terms of reactivity; they are crosslinkable and/or polymerizable by heat, which makes it possible to use conventional crosslinking/polymerization methods and furthermore at temperatures of less than 150° C. This reactivity is in particular due to the presence of a particular type of initiator based on a boron derivative; That initiator is active in low concentration and advantageously requires only small quantities of energy to carry out the crosslinkage/polymerization.

Abstract: Liquid phase liquid crystal polymers (LCPs) are disclosed having a composition and structure that can be varied to provide desirable properties. The liquid phase LCPs have polyiminoborane, polyaminoborane, and/or borozine polymer backbone molecules, with silicon and/or phosphorous side chain molecules linked to the backbone that provide a degree of alignment assigned an Order Parameter (S), defined as S=? [3 cos2 ??1], where ? is the angle between the axis of an LCP molecule and the vertical direction. The inventive liquid phase LCPs have an average Order Parameter in the range of about 0.2 to about 0.99 and are applicable to a number of rinse, coolant, lubricant, sterilization and other protectant processes.

Abstract: A new silicone condensation reaction, the condensation between an alkoxy silane or siloxane and an organo-hydrosilane or siloxane and catalysts therefore is described and claimed.

Abstract: A hydrolytic condensation coating composition includes a silane, an epoxy resin, a hydrolytic condensation catalyst, and a solvent. The weight ratio of the epoxy resin to the silane is 1:0.4˜6. The silane is reactable with the epoxy resin, and is hydrolyzable in the presence of the hydrolytic condensation catalyst to form a three-dimensional stereo-network structure. A hard coat film obtained by coating a plastic substrate with the coating composition, followed by thermo-curing, exhibits high transparency and hardness, and has excellent anti-scratch and chemical-resistant properties. The hard coat film is suitable for use as a surface protective film for displays, polarizers, touch panels, ITO conductive films, other optical elements, and the like.

Abstract: The invention relates to a method for producing a sealed impregnation and/or release coating of flat joints, in particular of cylinder-head gaskets such as composite seals, metallic joints and multi-layered steel joints. The invention uses a silicone composition including at least a polyorganosiloxane A crosslinkable by a cationic and/or radical process by appropriate crosslinking functional groups, for example, of the alkenyl ether, acrylic, acrylate, epoxide and/or oxethane type; at least an initiator salt B selected among onium borates or an organometallic complex; and at least a reactive diluent C including a nonorganosilicon or organosilicon compound comprising in its structure at least a crosslinking functional group and optionally a secondary functional group different from the crosslinking functional group but capable of chemically reacting with a crosslinking functional group, for example of the hydroxyl, alkoxy and/or carboxyl type.

Abstract: The invention concerns a radiation-curable silicone coating based on silicones having a viscosity not more than 1500 mPa's, radiation-curable, comprising: (a) at least a liquid polyorganopolysiloxane polymer Pa with viscosity higher than 500 mPa's and having at least a terminal unit of formula [Z—Si (R1)(R2)—O—] (I), and (b) at least a polyorganopolysiloxane polymer Pb, with viscosity less than 150 mPa's and having at least a unit of formula (I) defined above and/or at least a unit of type D of formula —[—(Si(R1)(Z)—O—]— (ii), Z being a crosslinkable and/or polymerisable group; (c) at least an efficient amount of at least an initiator consisting of onium borate.

Abstract: The invention relates to a heat-activated initiator for polymerising and/or cross-linking polyorganosiloxane-type monomers, oligomers and/or polymers with organofunctional groups, comprising a boron derivative of formula (I): (A)xB(R′)y, wherein the symbols R′ are the same or different and represent an alkyl or alkenyl radical in C1-C12, an alkoxy radical in C1-C12, a phenyl radical substituted by at least one electroattractor element, an aryl radical containing at least two aromatic rings such as biphenyl, naphthyl, optionally substituted by at least one electroattractor element, especially a halogen atom (particularly fluorine), or an electroattractor group, especially a CF3, NO2, CN group; and a radical —C2H4—Si(Q)3 with the symbols Q being the same or different and representing an alkyl or alkoxy group in C1 to C10 or a siloxane oligomer with less than 10 silicon atoms. The invention also relates to a corresponding cross-linkable composition and to the uses thereof.

Abstract: A composition having water-repellency at high temperature is provided. Some of the invention compositions also exhibits oil-repellency at high temperature. The composition comprises a fluorocarbon silane or hydrolyzate thereof; a surfactant; a polymerizable, silicon-containing compound; and a catalyst.

Abstract: A heat conductive adhesive film, wherein a magnetic field is applied to a film composition comprising boron nitride powder for orientating and solidifying the boron nitride powder in the composition in a given direction, an manufacturing method thereof, and an electronic component, characterized by that a heat radiating element and a heat conductive member are adhered by a heat conductive adhesive film wherein boron nitride powder is orientated in a given direction, presenting a high heat conductivity, an excellent heat radiation, and a good electric insulation and a high peeling-off strength.

Abstract: The invention concerns the field of polymerization and/or cross-linking reaction catalysis by cationic process of monomers, oligomers and/or polymers. In particular, novel polymerization and/or cross-linking initiator systems comprising at least one onium borate and at least one benzophenone are described to satisfy the ever greater exigencies of productivity and manufacture. The initiators are used in particular for preparing resins and/or composite materials based on an organic and/or silicon matrix or optionally a matrix of acrylic monomers, oligomers, or polymers.

Abstract: A weldable curable coating composition with improved intercoat adhesion is disclosed comprising a resinous binder comprising a polymer (A) with functional groups and a crosslinking agent with functional groups reactive with those of polymer (A); an electroconductive pigment; and an adhesion promoting compound comprising boron containing compounds. In an alternative embodiment, the adhesion promoting compound may comprise siloxane polymer reacted with aluminates, titanates, zirconates, silicates, siloxanes, silanes, and mixtures thereof, wherein each component is different.

Abstract: The invention concerns a polymerization and/or crosslinking method under electron beam and/or gamma radiation for compositions based on monomers, oligomers and/or polymers with organic functional groups. The invention is characterized in that the crosslinking and/or polymerization is carried out in the presence of an initiator capable of being activated under electron beam and/or gamma radiation comprising a boron derivative of formula (I) M+B(Ar) 4 wherein: M+, a unit bearing a positive charge, is an alkaline metal selected among those of columns IA and IIA of the periodic table; Ar is an aromatic derivative, optionally substituted by at least a substituent selected among a fluorine radical, a chlorine radical, a linear or branched alkyl chain, which itself can be substituted by at least a fluorine atom.

Abstract: The invention relates to compositions which can be prepared from at least one polyorganosiloxane, boric acid and water, and which may serve as a pelletizing additive for crosslinkable silicone rubber formulations. A small proportion of the pelletizing additive, when added to a ore component crosslinkable silicone rubber, or to individual components of a two or more component silicone rubber formulation, allow production of free flowing pellets which retain storage stability for extended periods of time.

Abstract: The invention concerns the use of cross-linkable silicone compositions for fast, economical and simple impregnation and/or varnishing of flat joints (e.g. cylinder head gaskets). More precisely it concerns the use of silicone compositions cross-linkable under UV radiation, by cationic process and in the presence of specific phoinitiators selected among onium borates or organometallic complexes, of which the borate counter-anions contain at least a boron bound to at least a substituted phenyl (Me, F). The silicone liquid precursor is a polydimethylsiloxane (PDMS) substituted by cross-linking functional groups, by cationic process (Gfp) under UV of the epoxy of vinyloxy type. These Gfp are present at the rate of 0.15 to 2.0 pr kg of PDMS. The invention also relates to the method for impregnating/varnishing flat joints (e.g. cylinder head gaskets) using the specific PDMS composition+photoinitiator of borate type as well as the treated joints and the composition themselves.

Abstract: Antireflective compositions characterized by the presence of an SiO-containing polymer having pendant chromophore moieties are useful antireflective coating/hardmask compositions in lithographic processes. These compositions provide outstanding optical, mechanical and etch selectivity properties while being applicable using spin-on application techniques. The compositions are especially useful in lithographic processes used to configure underlying material layers on a substrate, especially metal or semiconductor layers.

Abstract: This invention relates to a process of producing a siloxane copolymer comprising the step of reacting at least one diol, at least one dicarbonate and at least one silicon compound as copolymerization components in the presence of an esterification or transesterification catalyst, wherein the silicon compound is represented by the general formulas (I) and (II): wherein R1, R2, R3 and R4 are each independently a hydrogen atom or a substituted or non-substituted organic group; X and Y are each independently a hydrogen atom or a substituted or non-substituted organic group; a represents an integer of 0 to 5,000; and b represents an integer of 3 to 20.

Abstract: The invention relates to modified cationic photoinitiators which exhibit a reduced tendency to crystallize, to a process for reducing the crystallization tendency of cationic photoinitiators, and to the use of the photoinitiators of the invention for the radiation curing of cationically curing compositions. The inventive cationic photoinitiators have the formula (IV): [R1—I—R2]+X− where R1 is a radical R2 is a radical in which Ar is a monovalent aromatic hydrocarbon radical and D being a radical and the remaining variables are defined herein.

Abstract: The invention concerns a novel method for preparing non-toxic resins crosslinkable under radiation in the presence of an initiator system. Said resins are prepared from compositions of an organic and/or silicon type comprising monomers, oligomers and/or polymers with organofunctional groups, and are cross-linked in the presence of an initiator system consisting of an onium salt with low toxicity whereof the cationic structure is [(CH(CH3)2—C6H4—)—I—(—R1)]+(I).

Abstract: The invention concerns a composition cross-linkable under radiation. The composition includes at least one polyorganosiloxane with cross-linkable functional groups, a stabilizing amino agent, and an initiator system for hardening under radiation. The composition is stable for use and storage.

Abstract: An organofunctional cocyclic siloxane, i.e., a dialkyl, alkyl carboxyalkyl cocyclic siloxane, is used to prepare copolymeric siloxane fluids, copolymeric siloxane gums, and terpolymeric siloxanes via three polymerization techniques. In one embodiment, the dialkyl, alkyl carboxyalkyl cocyclic siloxane is polymerized using a bulk polymerization technique. In another embodiment, the dialkyl, alkyl carboxyalkyl cocyclic siloxane is polymerized using an emulsion polymerization technique. In an additional embodiment, the dialkyl, alkyl carboxyalkyl cocyclic siloxane is polymerized using a microemulsion polymerization technique. The dialkyl, alkyl carboxyalkyl cocyclic siloxane most preferred is a dimethyl, methyl carboxyalkyl cocyclic siloxane.

Abstract: A process for the production of polysiloxane/polycarbonate block cocondensation products is disclosed. The process comprises reacting in the melt at temperatures of 250 to 320.degree. C. and pressures of 0.01 to 100 mbar (a) a hydroxyaryloxy-terminated dimethylsiloxane with (b) an oligocarbonate. The oligocarbonate is characterized in that its weight average molecular weight is 3000 to 24000 and the molar ratio of its OH end groups to aryl end groups is 10:90 to 70:30. The weight ratio of said (a) to said (b) in the inventive process is between 1:99 and 40:60. Also disclosed are the products prepared by the process.

Abstract: Novel methods for the preparation of polymers useful as precursors to ceramic materials by catalytic activation of Si--H bonds are disclosed. The methods comprise reacting, in the presence of a catalyst effective to activate Si--H bonds, Si--N bonds, or both, and/or a reactive solvent, a polymer in the form of a polysilane, polysilazane, polysiloxane or polycarbosilane with a reactant having the structural formula R--X--H, wherein X is NR' or O, R is H, organic, silyl, siloxyl, silazanyl or carbosilyl and may contain at least one additional X--H group, and R' is H, amino, silyl or silazanyl, to produce a modified polymer containing at least one Si--X bond. Polymers produced by these methods are also disclosed.

Abstract: Compositions containing conductivity enhancers, which are capable of being coated onto a substrate by means of electrostatic assistance. The compositions comprise one or more cationically polymerizable monomer(s), one or more cationic initiator(s), and one or more non-volatile conductivity enhancer(s) having anionic and cationic portions which are soluble in the monomer(s) and which do not interfere with cationic polymerization wherein the anionic portion is a non-coordinating carbon-containing anion. The compositions may further comprise one or more dissociation enhancing agent(s), oligomer(s) or polymer(s), preferably co-reactive, free-radically curable monomer(s), free-radical generating initiator(s), leveling agents, and other additives or adjuvants to impart specific properties to the polymerized composition.

Abstract: A method of joining similar or dissimilar ceramic and ceramic composite materials, such as SiC continuous fiber ceramic composites, at relatively low joining temperatures uses a solventless, three component bonding agent effective to promote mechanical bond toughness and elevated temperature strength to operating temperatures of approximately 1200 degrees C. The bonding agent comprises a preceramic precursor, an aluminum bearing powder, such as aluminum alloy powder, and mixtures of aluminum metal or alloy powders with another powder, and and boron powder in selected proportions. The bonding agent is disposed as an interlayer between similar or dissimilar ceramic or ceramic composite materials to be joined and is heated in ambient air or inert atmosphere to a temperature not exceeding about 1200 degrees C. to form a strong and tough bond joint between the materials.

Abstract: The invention relates to a self-curing, photochemically or thermally curable resinous dental composition based on polymerisable polysiloxanes, to a process for its preparation and to its use for the preparation of pasty, self-curing, photochemically or thermally curable dental materials. Said composition is obtainable by hydrolytic condensation of one or more hydrolytically condensable silicon compounds, 1 to 100 mol %, based on monomeric compounds, of silanes of the general formula: Y.sub.n- SiX.sub.m R.sub.4-(n+m) and/or {X.sub.n R.sub.k Si?R.sup.2 (A).sub.l !.sub.4-(n+k) }.sub.x B being selected. The radicals A, X, Y, R.sup.2, R' and R are identical or different and have the following meaning: A=O, S, PR', POR', NHC(O)O or NHC(O)ONR', B=a straight-chain or branched organic radical which is derived from a compound B' having at least one (for l=1 and A=NHC(O)O or NHC(O)NR') or at least two C.dbd.C double bonds and 5 to 50 carbon atoms, R=alkyl, alkenyl, aryl, alkylaryl or arylalkyl, R'=H, alkyl or aryl, R.

Abstract: The synthesis and characterization of novel higher order, multi-arm star polymers comprising polyisobutylene arms connected to condensed cyclosiloxane cores are described. The synthesis has been achieved by hydrosilating olefin-capped (e.g., allyl- or isopropenyl-terminated) polyisobutylene with hydrogencyclosiloxanes carrying a plurality of Si--H groups and simultaneously and competitively converting SiH functions, in the presence of moisture, to Si--OH groups to rapidly self-condense or react with SiH groups to form coupled cyclosiloxane cores via core-core coupling. Thus, higher order stars having many more arms than first order stars can be formed.