Abstract: Silicon carbide is produced by chemical vapor deposition at temperatures from 1340.degree.-1380.degree. C., deposition chamber pressures of 180-200 torr, H.sub.2 /methyltrichlorosilane ratio of 4-10 and deposition rate of 1-2 .mu.m/min. Furthermore, H.sub.2 supplied as a part of the gas stream contains less than about 1 part per million (ppm) O.sub.2 gas, and various means are provided to exclude particulate material from the deposition chamber. The silicon carbide is polishable to <5 .ANG. RMS as measured on a Talystep mechanical profiler and has a thermal conductivity of at least about 300 W/mk. The silicon carbide is particularly suitable for applications where high polishability and thermal conductivity is desired, such as hard disc drives and read/write heads of head-disc assemblies, and also optical apparatus which require a very high polish.

Abstract: To a gas generant composition comprising a fuel component which includes a triazole compound and/or tetrazole compound with an acidic hydrogen and an oxidizer component which includes a transition metal oxide, is added a chelating agent, such as ethylenediaminetetraacetic acid (EDTA) to provide long-term stability to the gas generant composition.

Abstract: A gas generant composition contains as a fuel a mixture of a major portion of a triazole or tetrazole and a minor portion of a water soluble fuel; and an oxidizer component, at least 20 wt % of said oxidizer component being a transition metal oxide, such as CuO.

Abstract: Silicon carbide is produced by chemical vapor deposition at temperatures from 1340.degree.-1380.degree. C., deposition chamber pressures of 180-200 torr, H.sub.2 /methyltrichlorosilane ratio of 4-10 and deposition rate of 1-2 .mu.m/min. Furthermore, H.sub.2 supplied as a part of the gas stream contains less than about 1 part per million (ppm) O.sub.2 gas, and various means are provided to exclude particulate material from the deposition chamber. The silicon carbide is polishable to <5 .ANG. RMS as measured on a Talystep mechanical profiler and has a thermal conductivity of at least about 300 W/mk. The silicon carbide is particularly suitable for applications where high polishability and thermal conductivity is desired, such as hard disc drives and read/write heads of head-disc assemblies, and also optical apparatus which require a very high polish.

Abstract: To apply a photoimageable composition to a substrate, such as a printed circuit board, the photoimageable composition is dissolved in a solvent system which is a mixture of propylene glycol monomethylether and ethylene glycol butylether, acetate. The liquid solution is applied to the substrate. Then the photoimageable composition is dried to remove the solvent system and thereby produce a layer of the photoimageable composition on the substrate.

Abstract: 1. An isocyanate curative used for curing water-borne polyurethane adhesive compositions and providing enhanced water-resistance to the cured adhesive is the reaction product of A) between about 30 and about 60 wt. % one or more polyethers formed from alkyl oxides, between about 5 and about 40 mole percent of the total polyether content comprising propylene oxide units and between about 60 and about 95 mole percent of the total polyether content comprising polyethylene oxide units, B) between about 1 and about 10 wt % of an aliphatic diol(s), C) between about 10 and about 10 wt % of an aliphatic triol(s) or polyols having hydroxyl functionality greater than 3, and D) between about 30 and about 50 wt % of an aliphatic diisocyanate, the aliphatic diisocyanate being provided in an amount to provide an NCO/OH ratio of between about 1.5 and about 2, the curative having an NCO content of between about 5 and about 10 wt. % and an NCO equivalent weight of between about 400 and about 1200.

Abstract: A gas generant composition contains as a fuel a mixture of a major portion of a triazole or tetrazole and a minor portion of a water soluble fuel; and an oxidizer component, at least 20 wt % of said oxidizer component being a transition metal oxide, such as CuO. Generant compositions in accordance with the invention autoignite in a range around 170.degree. C., providing autoignition of the generant without the need for separate autoignition devices. Also, the generant compositions are useful as autoignition pyrotechnic in autoignition devices.

Abstract: A heat-resistant coating powder is comprised of A) between about 20 and about 83 wt % based on resin content of A) plus B) of a silicone resin having organic moieties selected from aryl and C.sub.1 -C.sub.4 alkyl, a degree of substitution of about 1.5 or less, and an --OH content of between about 2.5 and about 7.5 wt. %, B) between about 17 wt % and about 80 wt % based on resin content of A) plus B) of an acrylic resin having an acid number of between about 20 and about 100 and a hydroxyl number of about 5 or below, and C) an acid-reactive cross-linking agent(s) at a stoichiometry of between about 70 and about 110% of the acid functionality of said acrylic resin B).

Abstract: A waterborne photoimageable composition or photoresist comprises a latex binder polymer having acid acid functionality to render it developable in alkaline aqueous solution, at least about 50 mole percent of the acid functionality being sulfonic acid moieties, a photopolymerizeable monomer fraction, and a photoinitiator chemical system.

Abstract: A waterborne photoimageable composition or photoresist comprises a latex binder polymer having acid functionality to render it developable in alkaline aqueous solution, which acid functionality is neutralized to at least about 1 mole percent with an amino acrylate, a photopolymerizeable monomer fraction, and a photoinitiator chemical system.

Abstract: A method is provided for forming a high-resolution photoresist layer on a substrate, such as a metal-clad circuit board blank. A dry film is used which comprises a support sheet, a negative-acting, alkaline aqueous developable photoresist layer in direct contact with the support sheet, and a protective sheet. The protective sheet is removed and the photoresist layer is cut sheet laminated to the substrate. Then the support sheet is removed. The photoresist layer is baked until its exposed surface is non-tacky. Artwork is laid directly in contact with the non-tacky exposed surface, and the photoresist layer is exposed to actinic radiation through the art work. The photoresist layer is then developed in alkaline aqueous solution. The photoresist layer is highly resolved. Subsequent processing steps, such as plating or etching and stripping yield a printed circuit board having highly resolved lines and spaces.

Abstract: A waterborne photoimageable composition or photoresist comprises a latex binder polymer having sufficient carboxylic acid functionality to render it developable in alkaline aqueous solution, a photopolymerizeable monomer fraction, a photoinitiator chemical system and surfactant which is a fluoroaliphatic oxyethylene adduct.

Abstract: A waterborne photoimageable composition or photoresist comprises a latex binder polymer having sufficient carboxylic acid functionality to render it developable in alkaline aqueous solution, a photopolymerizeable monomer fraction, a photoinitiator chemical system and a poly(siloxane(s)).

Abstract: Silicon carbide is produced by chemical vapor deposition at temperatures from 1340.degree.-1380.degree. C., deposition chamber pressures of 180-200 torr, H.sub.2 /methyltrichlorosilane ratio of 4-10 and deposition rate of 1-2 .mu.m/min. Furthermore, H.sub.2 supplied as a part of the gas stream contains less than about 1 part per million (ppm) O.sub.2 gas, and various means are provided to exclude particulate material from the deposition chamber. The silicon carbide is polishable to <5 .ANG. RMS as measured on a Talystep mechanical profiler and has a thermal conductivity of at least about 300 W/mk. The silicon carbide is particularly suitable for applications where high polishability and thermal conductivity is desired, such as hard disc drives and read/write heads of head-disc assemblies, and also optical apparatus which require a very high polish.

Abstract: Photoemulsion is reduced with a combination of reducing sugar and sodium borohydride, resulting in increased silver recovery.

Abstract: To form a sparkle finish by powder coating, an opaque initial layer is first applied to a substrate, e.g., by powder coating. Then a mixture of glass flake and clear coating powder is prepared by blending. This mixture is then applied to a substrate, e.g., electrostatically, and heated to fuse and/or cure the coating powder.

Abstract: A waterborne photoimageable composition or photoresist comprises a latex binder polymer having sufficient carboxylic acid functionality to render it developable in alkaline aqueous solution, a photopolymerizeable monomer fraction, a photoinitiator and a polyether polyurethane associate thickener which supports an emulsion of the monomer fraction in aqueous medium. The carboxylic acid functionality of the latex binder polymer is neutralized at from 0 to about 20%.

Abstract: A photoimageable composition includes a polymeric binder which is soluble in aqueous solution; a cross-linking agent for the polymeric binder; a polymerizable acrylic substance; a chemical, photosensitive, free radical-generating initiating system; and a liquid epoxy resin composition and an epoxy cure catalyst. In one method of using the photoimageable composition of the present invention, the composition is applied as a film to a substrate, heated to make the film non-tacky but still aqueous-soluble, exposed to actinic radiation, developed in aqueous solutions to wash away non-exposed portions of the film and heat-cured to harden the film.

Abstract: Unique phase morphologies of incompatible thermoplastic polymers, including a higher melting temperature polymer and a lower melting temperature polymer that has been sufficiently chemically compatibilized to form a stable interface in a two-phase system, are achieved by pre-melting the higher melting temperature polymer, adding the compatibilized lower melting temperature polymer in solid form thereto, and thereafter melting the lower temperature polymer with mixing. In particular, in poly(ethylene vinyl alcohol)/modified polyolefin systems, compositions containing between about 35 and about 55 wt. percent EVOH are formed in which the poly(ethylene vinyl alcohol) exists as a continuous phase and the modified polyolefin exists as discrete domains dispersed therein. Such blended compositions have gas barrier properties comparable to homogeneous poly(ethylene vinyl alcohol).

Abstract: Viscoelastic resins useful for forming vibration damping composites, i.e., metal layers adhered by the resins, contain only the elements hydrogen, oxygen and carbon and provide vibration damping over a wide temperature range. The resins are generally linear, high molecular weight polymers having blocks of epoxy and either polyester or polyether.