Abstract: The present invention provides a continuous series of at least 3 esterification reactions, each of which yields highly pure esters derived from benzoic and at least one alcohol selected from monohydric alcohols containing from 6 to 12 carbon atoms and dihydric alcohols containing from 2 to 8 carbon atoms. At least a portion of the esterification catalyst and high boiling impurities remaining following distillation of the desired ester are used in the reaction mixture for the next reaction of the series.
Type:
Grant
Filed:
August 7, 2000
Date of Patent:
May 22, 2001
Assignee:
Velsicol Chemical Corporation
Inventors:
Wesley Wayne McConnell, Bruce Edward Stanhope, Franz Josef Luxem
Abstract: This invention provides a highly efficient method for fabricating toner fixing rolls comprising a cured silicone rubber layer covering a metal core and a fluororesin film covering the silicone rubber layer. The characterizing feature of the present method is coating the inner surface of the fluororesin film with an organohydrogenpolysiloxane prior to contacting the film with the curable silicone rubber composition. The resultant roll is robust, highly toner-releasing; and low in hardness, and the fluororesin film and cured silicone rubber are firmly bonded to one another.
Abstract: Rear view mirror mounting brackets are adhesively bonded to a windshield using a relatively small, portable rework fixture that can be temporarily secured to an automotive windshield by means of suction cups. The framework of the fixture supports a pair of movable guide rods connected to a metal block equipped with a heating element and having a surface that holds the adhesive coated mounting bracket. The guide rods are equipped with compressible springs that maintain the block and associated mounting bracket in close contact with the windshield during curing of the layer of heat-curable bonding adhesive present on the surface of the bracket that is in contact with the windshield.
Abstract: This invention provides foam-covered rolls comprising silicone foam layer over a metal core and a fluororesin film laminated over the foam layer. The cured foam layer is obtained by using as the blowing agent the hydrogen gas generated by the reaction of an organohydrogenpolysiloxane with a compound containing at least one hydroxyl group per molecule. The resultant rolls are very durable, highly toner-releasing and are free of creases on the roll surface. Using the fabrication method that constitutes one embodiment of the present invention, foam covered rolls can be produced very efficiently.
Abstract: This invention provides curable compositions comprising a polytitanosiloxane containing at least two alkenyl radicals per molecule and a crosslinking agent that is either 1) the combination of an organohydrogensiloxane containing at least two silicon-bonded hydrogen atoms per molecule and a platinum-containing catalyst or 2) an organic peroxide. This invention also provides a method for curing a polytitanosiloxane by reacting it with the crosslinking agent of the present compositions.
Abstract: A stable dispersion of a finely divided solid such as a pigment in an organosiloxane composition can be prepared as a homogeneous thixotropic liquid, paste or gel by blending the solid with a finely divided, partially treated silica, a specified class of liquid diorganosiloxane/oxyalkylene copolymers and, as a diluent, at least one liquid organosiloxane oligomer having a density lower than the density of the dispersed solid. The gels and pastes convert to flowable liquids when subjected to shearing forces.
Abstract: Curable silicone compositions comprise either (a) microparticles of a fluororesin which exhibits low adhesion to the cured composition, or (b) microparticles of an organic or inorganic material whose surfaces have been coated with this type of fluororesin. The compositions are useful coatings for semiconductor devices requiring high levels of moisture and heat resistance.
Abstract: This application is concerned with room temperature vulcanizing compositions useful as mould making materials which are formed by mixing an alpha, omega dihydroxy polysiloxane, a condensation polydimethylsiloxane, catalyst and a crosslinking agent which comprises a tri- or tetra-alkoxy silane or siloxane in which the alkoxy groups contain more than two carbon atoms. Moulds made with these materials on epoxy masters show improved usage; the improvement is related to the size of the alkoxy "leaving group" and the proportion of crosslinker and condensation catalyst.
Abstract: The present invention provides organosiloxane compositions that cure to optically transparent gels by a hydrosilation reaction and contain a) two types of alkenyl-substituted organopolysiloxanes, and b) a diorganopolysiloxane containing an average of at least two silicon-bonded hydrogen atoms per molecule that are located on non-terminal silicon atoms. The molar ratio of silicon-bonded hydrogen atoms to alkenyl radicals in the composition is from 0.1 to 1.2.
Abstract: Liquid adhesion-promoting compositions for cohesively bonding organosiloxane materials to organic polymers comprise (A) a copolymer derived from at least one ethylenically unsaturated organic compound and at least one silane containing an ethylenically unsaturated organic group and at least two silicon-bonded hydrolyzable groups per molecule, (B) an organohydrogensiloxane, (C) an aminosilane containing at least 2 alkoxy or other hydrolyzable groups, and (D) an amount of an organic liquid sufficient to solubilize ingredients A, B and C of said composition and achieve the desired viscosity.
Abstract: Adhesion-promoting additives for use in curable organosiloxane compositions comprise 1) at least one organosiloxane comprising a) silicon bonded hydrogen atoms and/or ethylenically unsaturated substituents bonded to silicon through carbon and b) at least one silicon atom containing three hydrolyzable groups, and 2) at least one silane containing four alkoxy or enoloxy groups or three of these groups and a hydrocarbon radical containing an epoxy or ethylenically unsaturated group as a substituent.
Abstract: A stream of a molten moisture curable organosiloxane composition is entrained in a current of a heated gas containing a concentration of water vapor below the saturation level of the gas at 25.degree. C. The gas current directs the organosiloxane composition toward the surface to be coated and provides an environment adjacent to the surface of the coated substrate that causes at least the surface layer of the composition to cure at a rate that is substantially constant and independent of the temperature and humidity in the macroscopic environment of the substrate.
Type:
Grant
Filed:
April 29, 1994
Date of Patent:
April 9, 1996
Assignee:
Dow Corning Corporation
Inventors:
Michael R. Strong, Bernard VanWert, Martin E. Cifuentes
Abstract: This invention provides 1) novel reactive fluorinated compounds derived from a specified class of telomers or cotelomers of fluoroolefins; and 2) stable products and stable polymers thereof obtained by reaction or polycondensation of the novel reactive fluorinated compounds with specified classes of hydrogenated aliphatic, alicyclic, aromatic reactive compounds, telechelic oligomers and block polymers wherein said stable products and polymers contain hetero atoms such as oxygen, sulfur or nitrogen and are characterized by high thermal and chemical resistance.
Abstract: The novel organosiloxane compounds of the present invention are characterized by the presence of 1) a silicon atom containing at least two alkoxy or other hydrolyzable groups and the group --OR.sup.1 Si.dbd. wherein R.sup.1 represents a divalent organic group comprising carbon, hydrogen, and, optionally, oxygen, and 2) a silicon bonded hydrogen atom or alkenyl radical. A preferred method for preparing the compounds is by the reaction of 1) a silane containing a silicon-bonded alkenyloxy group and at least two silicon-bonded hydrolyzable groups or a precursor of said hydrolyzable groups and 2) an organohydrogensiloxane. The reaction is conducted in the presence of a hydrosilation catalyst.
Abstract: The present invention relates to organosiloxane compositions that are reaction products of 1) a silane containing at least 3 hydrolyzable groups per molecule, 2) a monohydric or polyhydric alcohol containing at least one organofunctional group and 3) a polyhydric alcohol containing no organofunctional groups or ethylenic unsaturation, wherein said reaction products contain at least two silicon atoms. The organosiloxane compositions are particularly useful as adhesion promoting additives for curable organosiloxane compositions, particularly those that cure by a platinum group metal-catalyzed hydrosilation reaction.
Abstract: The compression set values of cured elastomers prepared from finely divided organosiloxane elastomer bases are reduced by treating the base with a silane or disilazane wherein the silicon atoms are bonded to one hydrolyzable group and three hydrocarbon radicals that are free of ethylenic unsaturation. The base is maintained in a fluidized state during this treatment.
Abstract: The present lubricant compositions comprise a mixture of graphite, molybdenum disulfide and polytetrafluoroethylene in specified proportions within a matrix of an organic resin. When applied to surfaces that are in sliding contact with one another the compositions exhibit high wear resistance, good initial conformability, and a coefficient of friction following use that is lower than the initial coefficient of friction. The compositions are particularly suited for application to engine pistons.
Type:
Grant
Filed:
November 2, 1994
Date of Patent:
January 23, 1996
Assignees:
Dow Corning Asia, Ltd, Toyota Motor Company
Abstract: The present invention provides organosiloxane copolymers comprising SiO.sub.4/2 units, silicon-bonded hydrolyzable groups, epoxy or acryloxyalkyl groups and silicon-bonded hydrogen atoms. The copolymers are particularly useful as adhesion promoting additives in organosiloxane compositions that cure by a platinum group metal-catalyzed hydrosilation reaction at temperatures up to 100.degree. C.
Abstract: Liquid adhesion-promoting compositions for cohesively bonding organosiloxane materials to organic polymers comprise (A) a copolymer derived from at least one ethylenically unsaturated organic compound and at least one silane containing an ethylenically unsaturated organic group and at least two silicon-bonded hydrolyzable groups per molecule, (B) an organohydrogensiloxane, (C) an aminosilane containing at least 2 alkoxy or other hydrolyzable groups, and (D) an amount of an organic liquid sufficient to solubilize ingredients A, B and C of said composition and achieve the desired viscosity.
Abstract: Adhesion promoting compositions for bonding a layer of organic polymer to a layer of organosiloxane elastomer during curing of the elastomer by a platinum group metal-catalyzed hydrosilation reaction comprise (a) a copolymer containing repeating units derived from at least one ethylenically unsaturated organic compound and at least one silane containing an ethylenically unsaturated organic group and at least two silicon-bonded hydrolyzable groups per molecule, and (b) an organohydrogensiloxane containing an average of at least three silicon-bonded hydrogen atoms per molecule. If the adhesion promoting composition is to be used with an elastomer prepared by curing an organosiloxane elastomer at temperatures below about 80 degrees C., the adhesion promoting composition includes an alkyl orthosilicate and an organotitanium compound.