Abstract: Thick opaque ceramic coatings are used to protect delicate microelectronic devices against excited energy sources, radiation, light, abrasion, and wet etching techniques. The thick opaque ceramic coating are prepared from a mixture containing tungsten carbide (WC), tungsten metal (W), and phosphoric anhydride, i.e., phosphorous pentoxide (P.sub.2 O.sub.5), carried in an aqueous alkanol dispersion of colloidal silica and partial condensate of methylsilanetriol. The coating is pyrolyzed to form a ceramic SiO.sub.2 containing coating. A second coating of plasma enhanced chemical vapor deposited (PECVD) silicon carbide (SiC), diamond, or silicon nitride (Si.sub.3 N.sub.4), can be applied over the thick opaque ceramic coating to provide hermeticity. These coatings are useful on patterned wafers, electronic devices, and electronic substrates. The thick opaque ceramic coating is unique because the methyl silsesquioxane resin is resistant to etching using wet chemicals, i.e., acids such as H.sub.3 PO.sub.4 and H.sub.

Abstract: Disclosed are novel ceramic matrix composites in which coated refractory fibers are imbedded in a ceramic matrix derived from a modified hydrogen silsesquioxane resin.

Abstract: The instant invention pertains to a method of producing silicone pressure sensitive adhesives wherein the method comprises (I) combining together (A) a benzene soluble, hydroxyl containing organopolysiloxane resin consisting essentially of R.sub.3 SiO.sub.1/2 siloxane units and SiO.sub.4/2 siloxane units, wherein R is a monovalent radical selected from the group consisting of hydrocarbon and halogenated hydrocarbon radicals having from 1 to 10 carbon atoms; there being from 0.5 to 1.5 R.sub.3 SiO.sub.1/2 units for every SiO.sub.4/2 units and there being 1.0 to 4 wt %, based on FTIR, hydroxyl functionality and (B) a hydroxyl containing polydiorganosiloxane having a viscosity of .gtoreq.100 mPa's and (C) a catalyst selected from the group consisting of a weak organic acid or metal salt thereof; and thereafter (II) heating the mixture of (A), (B) and (C) for a time sufficient to produce the silicone pressure sensitive adhesive.

Abstract: The instant invention pertains to a multi-layer tamper proof electronic coating wherein the first layer is a protecting layer produced from preceramic silicon containing material and at least one filler. The second layer is a resin sealer coat produced from a sealer resin selected from the group consisting of colloidal inorganic-based siloxane resins, benzocyclobutene based resins, polyimide polymers, siloxane polyimides and parylenes. An optional third layer is a cap coating layer selected from SiO.sub.2 coating, SiO.sub.2 /ceramic oxide coating, silicon containing coatings, silicon carbon containing coatings, silicon nitrogen containing coatings, silicon oxygen nitrogen coatings, silicon nitrogen carbon containing coatings and/or diamond like coatings.

Abstract: Disclosed are compositions which can be used to form tamper-proof coatings on electronic devices. These compositions contain a silica precursor resin and a filler which reacts in an oxidizing atmosphere to liberate heat. Such compositions form coatings which, when oxidized by techniques such as plasma etching, wet etching, or cross-sectioning, liberate heat which causes destruction of the underlying substrate and, thus, inhibits further examination.

Abstract: A method of crosslinking a silazane polymer having Si--H bonds in which the polymer is mixed with a crosslinker selected from alkenyl functional cyclosiloxanes and alkenyl functional cyclosilazanes and a crosslinking promoter and then heated to a temperature sufficient to crosslink the silazane polymer. The mixture of the silazane polymer, crosslinker and promoter is useful in the formation of ceramic matrix composites.

Abstract: A silicone-modified water-based coating composition is disclosed wherein a suspension of silicone rubber particles in water is added to a water-based coating composition such that the resulting system is storage-stable and forms a mat film when dried or cured, which film is soft to the touch.

Abstract: A process for the preparation of substantially polycrystalline silicon carbide fibers is provided. The fibers may be fabricated to have a small diameter and are thermally stable at high temperatures. The process is carried out by initially forming fibers from a preceramic polymeric precursor comprising methylpolysilane resins. The fibers are then infusibilized to render them nonmelting followed by a pyrolysis step in which the fibers are heated to a temperature in excess of 1600.degree. C. in a nonoxidizing atmosphere to form substantially polycrystalline silicon carbide fibers. The substantially polycrystalline silicon carbide fibers which are formed by the process of the present invention have at least 75% crystallinity and have a density of at least about 2.9 gm/cm.sup.3. The polymeric precursor or the fibers contain, or have incorporated therein, at least about 0.2% by weight boron.

Abstract: Disclosed are coating compositions which include a preceramic silicon-containing material dissolved in short chain linear siloxanes. The compositions have a long shelf life and are useful for forming coatings which are thick and of good quality.

Abstract: Fiber reinforced ceramic matrix composites are prepared by coating refractory fibers having a interfacial coating thereon with a curable preceramic polymer having a char which contains greater than about 50% sealant oxide atoms followed by forming the coated fibers into the desired shape, curing the coated fibers to form a pre-preg, heating the pre-preg to form a composite and heating the composite in an oxidizing environment to form an in situ sealant oxide coating on the composite. The resultant composites have good oxidation resistance at high temperature as well as good strength and toughness.

Abstract: This invention pertains to a method for producing an insoluble coating on a substrate by curing a composition comprising hydrogen silsesquioxane at a temperature of 375.degree. C. or less for a time sufficient to produce a coating having >80% SiH. It has been found that when the hydrogen silsesquioxane resin is cured at a temperature of 375.degree. C. or less that that the insoluble SiH containing coating shows improved film stress.

Abstract: This invention pertains to an addition-curable silicone adhesive composition that is extrudable and flowable at room temperature in the absence of a solvent comprising (A) 40 to 95 parts of an alkenyl functional siloxane resin consisting essentially of R.sub.3 SiO.sub.1/2 siloxane units and SiO.sub.4/2 siloxane units, wherein R is a monovalent hydrocarbon radical having 1 to 6 carbon atoms; there being from 0.5 to 1.5 R.sub.3 SiO.sub.1/2 units for every SiO.sub.4/2 units; said resin containing 0.01 to 22 wt % alkenyl functionality; (B) 0.5 to 10 parts of an SiH containing polyorganosiloxane having an average of at least 2 silicon-bonded hydrogen atoms per molecule and having a viscosity of 0.8 to 2,000 mm.sup.2 /s; (C) a hydrosilylation catalyst in sufficient quantity to promote curing of said composition; (D) optionally, up to 70 parts of a polydiorganosiloxane having at least two ethylenically or acetylenically unsaturated groups per molecule and having a viscosity of 100 to 80,000 mm.sup.

Abstract: The invention pertains to an dual-cure silicone adhesive composition that is extrudable and flowable at room temperature in the absence of a solvent comprising (A) 40 to 95 parts of an alkenyl functional siloxane resin said resin containing 0.01 to 22 wt% alkenyl functionality; (B) 0.5 to 20 parts of a SiH containing polyorganosiloxane having an average of at least 1.7 silicon-bonded hydrogen atoms per molecule and having a viscosity of 0.8 to 2,000 mm.sup.2 /s; (C) a silane represented by monomers of the formula R.sup.1.sub.4-y Si(OR.sup.2).sub.y or oligomeric reaction products thereof; (D) a hydrosilylation catalyst in sufficient quantity to promote curing of said composition; (E) a moisture curing catalyst to promote the moisture initiated reaction of the alkoxy radicals; (F) optionally, 0.1 to 70 parts of a polydiorganosiloxane having at least two ethylenically or acetylenicaly unsaturated groups per molecule and having a viscosity of 100 to 80,000 mm.sup.

Abstract: Disclosed is a method of forming tamper-proof coatings on electronic devices. The method comprises applying a coating of a silica precursor resin and an inorganic salt onto the electronic device, wherein the inorganic salt is one which reacts with a wet etch to yield an acid or base that damages the electronic device. The coated electronic device is then heated at a temperature sufficient to convert the silica precursor resin to a silica containing ceramic matrix.

Abstract: Encapsulated aluminum salts are produced by combining and heating an aqueous aluminum salt selected from aluminum halohydrate, aluminum nitrohydrate and mixtures thereof; a hydrophobic liquid; and a carboxylate. The mixture is heated until substantially all of the free water has been removed. The encapsulated aluminum salts precipitate out after the removal of the water. The encapsulated aluminum salts are useful in deodorant and antiperspirant compositions.

Abstract: A method of crosslinking a silazane polymer having Si--H bonds in which the polymer is mixed with a crosslinker selected from alkenyl functional cyclosiloxanes and alkenyl functional cyclosilazanes and a crosslinking promoter and then heated to a temperature sufficient to crosslink the silazane polymer. The mixture of the silazane polymer, crosslinker and promoter is useful in the formation of ceramic matrix composites.

Abstract: The instant invention pertains to a hot-melt pressure sensitive adhesive composition wherein the composition is comprised of a silicone pressure sensitive adhesive selected from the group consisting of a mixture of (i) a silicone resin and (ii) a silicone fluid and a condensed product of (i) and (ii); the silicone pressure sensitive adhesive exhibiting tackiness and adhesiveness; the silicone pressure sensitive adhesive being blended with (iii) from about 1 to 20 weight percent, based on the total weight of (i) and (ii), of a siloxylated polyether wax. The instant invention also encompasses method of using the composition, methods of making hot-melt silicone pressure sensitive adhesive-coated substrates, and devices made using the composition.

Abstract: The present invention relates to a method of forming coatings on electronic substrates and the substrates coated thereby. The method comprises applying a coating comprising hydrogen silsesquioxane resin and a polysilazane on a substrate and heating the coated substrate at a temperature sufficient to convert the resins to ceramics.

Abstract: A lithium ion battery electrode formed by the pyrolysis of a silazane polymer followed by introducing lithium ions. These electrodes can be used to form batteries with large capacities, low irreversible capacity, high density and good safety behavior.

Abstract: Disclosed are coating compositions which include hydrogen silsesquioxane resin dissolved in saturated alkyl hydrocarbons. The compositions are useful for forming coatings which are thick and/or have good coating quality.