Abstract:
Compositions d'organopolysiloxane reactives par reaction d'hydrosilylation catalysee par le platine qui est inhibee pendant des heures a la temperature ambiante mais qui a lieu rapidement a des temperatures aussi basses que 180 F. On obtient cela en melangeant un composant inhibiteur de reaction et un composant accelerateur de reaction avec la composition reactive. Des compositions de revetement de papier possedant une duree de vie prolongee a la temperature ambiante et un temps de polymerisation court a 180 F sont aussi decrites.
Abstract:
Hydrophobic reinforcing silica fillers for silicone rubber are produced by the steps of mixing an alkyl silicate, preferably methyl orthosilicate, at least 70% of one-half of the stoichiometric amount of water required to hydrolyze the alkoxy radicals present in the alkyl silicate, an alcohol and at least 0.05 moles (per mole of theoretical SiO2 units present in the alkyl silicate) of a hydrophobe agent such as hexamethyldisilazane together in the presence of a basic catalyst, said hydrophobe agent being added prior to the gelation of the mixture, and aging the mixture to obtain a composition contained a hydrophobic reinforcing silica filler for silicone rubber. Preferably, the hydrophobe agent is added prior to or concurrently with the addition of the alkyl silicate. Vulcanized silicone rubbers possessing tensile strengths in excess of 12.4 megapascals and tear strengths of greater than 31 kiloNewtons/meter can be prepared using the above fillers.
Abstract:
Simplified method of waterproofing masonry walls such as basement walls subjected to water from the outer surface by coating the inner surface with an anionic silicone emulsion that dries to produce an elastomeric film. The silicone emulsion consists essentially of an anionically stabilized hydroxyl endblocked polydiorganosiloxane, amorphous silica, and an organic tin salt, the emulsion having a ph of 9 or greater. The emulsion coating when dried provides an elastomeric film that bonds to the surface with sufficient force to resist the pressure of any water that may diffuse through the wall from the outer surface. The method of this invention provides a waterproof coating that also resists the effects of cracks in the substrate, temperature extremes, molds, fungus, or mildew, as well as possessing a long useful life.
Abstract:
Oxygen curable compositions are provided by mixing mercoaptoorganopolysiloxanes with a metal salt of a carboxylic acid wherein the metal is iron, copper, cobalt, manganese, or nickel.
Abstract:
Mixing mercaptoorganopolysiloxanes with a selected transition metal compound, an organic peroxide and optionally a filler, provides useful new compositions such as materials curable to elastomers at room temperature.
Abstract:
Masque nasal (11) servant a l'administration d'un ou plusieurs gaz tels que de l'oxygene a un etre humain comprenant, en combinaison, I) une coquille (10) possedant une partie anterieure (12), une partie posterieure (13) et une premiere ouverture comprenant sensiblement toute la zone horizontale au-dessous du nez du patient et II) un tube creux de distribution de gaz (15) contenant au moins un moyen (16) de distribution et de dispersion de gaz. Le masque (11) permet au patient de respirer, de manger et de parler de maniere sensiblement normale tout en lui fournissant de maniere efficace un nuage de gaz (enrichi par le gaz ou les gaz administres) directement au-dessous du nez et devant la bouche. Le masque (11) est particulierement utile dans des applications a long terme de la therapie a l'oxygene.
Abstract:
A sun position sensor including a plurality of solar sensors sensing solar energy arriving in a respective azimuth and elevational direction, data encoding means for a series of respective solar azimuth and elevational positions, each position corresponding to a respective solar sensor and wherein said data encoding means are coupled to the solar sensors to derive a sensed solar position, a solar collector effective for receiving solar energy in a discrete direction, drive means positioning the solar collector and providing position data corresponding to the position of the solar collector, and comparator means comparing the collector position and the solar position and providing a drive signal until the two positions are equal. A geodesic dome portion includes several facets each of which contains a respective plurality of solar sensors to provide an electrical output signal representing the amount of solar incidence on a respective sensor/dome facet.
Abstract:
Composites de carbure de silicium frittes contenant des cristaux de diamant. Ils sont fabriques par le procede suivant qui consiste a: (a) former une premiere dispersion de cristaux de diamant et de noir de carbone dans de la paraffine; (b) former une seconde dispersion de fibres de carbone, de noir de carbone et d'un materiau de remplissage dans de la paraffine; (c) compacter les dispersions ensemble pour produire un produit composite a deux couches solidaires; (d) mettre le produit composite sous vide pendant une periode de temps et a une temperature suffisantes pour vaporiser sensiblement toute la paraffine; (e) chauffer le silicium pour provoquer la liquefaction et l'infiltration directes dans les deux couches du composites; et (f) fritter le produit composite contenant du silicium dans des conditions suffisantes pour produire un liant de carbure de silicium (Beta) liant le composite. Les composites obtenus sont particulierement utiles comme materiaux de coupage et/ou composants anti-usure, faisant preuve d'une resistance extreme a l'usure.
Abstract:
Aqueous slurries of fine coal are dewatered by a process which comprises mixing an organopolysiloxane with the slurry, separating the slurry to recover the fine coal and further drying the fine coal, if desired. The use of water-soluble organopolysiloxanes or water-emulsifiable organopolysiloxanes provides improved separating and/or improved drying of fine coal in the dewatering process that is disclosed.
Abstract:
Mixing mercoaptoorganopolysiloxanes with a stannous salt of a carboxylic acid, and optionally an organic peroxide and/or a filler, provides useful new compositions such as materials which are curable to elastomers at room temperature.