Abstract: A new organohydrogenpolysiloxane compound and a new fluorosilicone polymer each have unique properties which allow for the preparation of faster curing coating compositions having longer bath life than those disclosed in the art. In a preferred embodiment the new polymers are mixed together to provide, along with a metal-containing hydrosilylation catalyst and a catalyst inhibitor to provide improved coating compositions which are useful for preparing a release liner to protect silicone pressure sensitive adhesives.
Abstract: A process for preparing a release liner for pressure-sensitive adhesives makes use of an organic-solvent solution of a rhodium-curable organopolysiloxane composition. The composition contains a high-viscosity, alkenyl-containing organopolysiloxane gum and an organohydropolysiloxane. The liner is particularly useful for releasing acrylic adhesives which have been applied in-line thereto.
Abstract: An adhesive release composition containing specific amounts of an organopolysiloxane bearing oxyalkylene groups and alkenyl groups, an organohydrogenpolysiloxane, and a platinum-type catalyst is characterized by the formation, on various base surfaces, of a release surface having an excellent printability and a stable release force. For example, a roll of pressure sensitive adhesive tape of this invention can be easily unrolled, durably adhered to an article and clearly printed with ink on its adhesive-releasing surface which bears the release composition of this invention.
Abstract: Aqueous emulsions of curable silicone compositions provide cured coatings having improved gloss and/or water-repellancy and/or adhesive release if formulated to contain polyvinylachohol having a degree of hydrolysis of 90 mol % or more. The extent of improvement is directly related to the degree of hydrolysis of the PVA. PVA having an average degree of hydrolysis of from 94 to 99 mol % is particularly effective for improving these properties of cured coatings. Conveniently, a mixture of two or more commercially available PVAs having different degrees of hydrolysis can be used to arrive at a PVA having a desired degree of hydrolysis.
Abstract: A microemulsion with an average particle size not exceeding 0.15 micrometers or organopolysiloxane composed of trifunctional siloxane units with the formula RSiO.sub.3/2 and difunctional siloxane units with the formula R.sup.1.sub.2 SiO is characterized by transparency, by excellent mechanical, dilution, and blending stabilities and by an excellent stability against pH variations. The microemulsion is prepared by process comprising the slow addition, to an aqueous emulsion-polymerization catalyst solution, of a crude emulsion prepared from an organotrialkoxysilane having the formula RSi(OR.sup.1).sub.3, a cyclic organopolysiloxane having the formula (R.sup.1.sub.2 SiO).sub.n, a surfactant, and water. A microemulsion which consists of 30 to 95 mol % trifunctional siloxane units and 70 to 5 mol % difunctional siloxane units is useful as a fiber-treatment agent that can impart slip resistance to fibrous material without stiffening the hand, while at the same time not causing oil spots.
Abstract: A novel primer composition containing a partial hydrolyzate of an aminoalkyl-substituted trialkoxysilane, a carboxylic acid salt of tin and a solvent is applied to a moisture-cured silicone substrate and dried to improve the adhesion of a subsequently applied coating. The composition and method are of particular value for painting a moisture-cured silicone substrate disposed on a support, such as a building sealant used on a window assembly or an encapsulant used on an electrical device.
Abstract: A release agent composition which manifests almost no silicone migration and a very low slickness while nevertheless having a low release value is achieved by means of a release agent composition which is based on a methylalkenylpolysiloxane, an alkylhydrogenpolysiloxane crosslinker for the methylalkenylpolysiloxane, an organopolysiloxane containing monovalent hydrocarbon groups which lacks aliphatically unsaturated bonds and which contains 6 to 18 carbon atoms which functions to lighten the releaseability of the cured film, to check silicone migration, and to reduce the slickness, and a catalytic quantity of a platinum-type catalyst.
Abstract: Curable organosilicon compounds which contain (meth)acryl-amido-substituted hydrocarbon radicals have their viscosities greatly reduced by the addition of a small amount of a vinyl monomer compound. Advantageously, the resulting compositions are more easily applied to a substrate, such as paper, in fast-paced coating operations without the significant loss of useful properties, such as the cure rate of the curable composition and the adhesive release behavior of the cured composition.
Type:
Grant
Filed:
February 9, 1987
Date of Patent:
March 27, 1990
Assignee:
Dow Corning Corporation
Inventors:
John R. Keryk, Padmakumari J. Varaprath, Antony P. Wright
Abstract: Dioxolane-substituted silicon compounds are prepared by a hydrosilylation reaction between a silicon hydride and an aliphatically unsaturated dioxolane compound. The dioxolane-substituted silicon compounds are thereafter converted to diol-substituted silicon compounds and then to diacrylate-substituted silicon compounds. The latter are useful in a curable coating composition for providing a substrate with an adhesive-releasing coating.
Abstract: The addition-curable composition of the present invention, because it comprises a special component as component (D), is characterized by an excellent bonding to any of various substrates with which it is in contact during curing. Component (D) is a mixture, or reaction product, of (a) a silicon-free compound which contains at least 1 alcoholic hydroxyl group and at least 1 alkenyl group in each molecule, and (b) an organosilane having in each molecule at least 1 alkoxy group and at least 1 epoxy or methacryloxy or acryloxy group.
Abstract: An organopolysiloxane with contains alkoxy radicals and epoxy-containing radicals on its molecular terminals has been found to be useful for treating fibers to provide a durable softness and flexibility, smoothness, wrinkle resistance, or rebound to fibrous material. The organopolysiloxane is substantially free of oligomers so that, during drying in the fiber treatment process, oil does not collect on exhaust fans and drip onto the treated material, causing oily spots.
Abstract: Beta-substituted allylsilanes are synthesized in a one-step process from readily available starting materials by the reaction of a specific carboxylic acid ester or acid anhydride with a specific alkoxy group-containing Grignard reagent in an organic solvent. The resulting allylsilanes are useful as allyl transfer reagents for electrophilic reagents such as ketones, carboxylic acid chlorides, etc.
Abstract: Pressure sensitive adhesives can be protected with a releasable liner having a cured fluoroalkyl silicone coating which contains as little as two percent fluoroalkyl-substituted siloxane units. In a preferred embodiment of this invention silicone pressure sensitive adhesives can be solvent-cast, and even cured, directly onto the release surface of the liner and can be removed from the protective liner with a force of not more than 400 grams per inch. The fluoroalkyl silicone copolymers of this invention are prepared by a process which involves the preparation of a cohydrolyzate of fluoroalkyl-containing and fluoroalkyl-free siloxane units, followed by further polymerization of the cohydrolyzate with other siloxane units.
Abstract: Radiation-curable organopolysiloxane compositions containing an alkenyl-substituted organopolysiloxane, a mercaptoalkyl-substituted organopolysiloxane and an aliphatically unsaturated silicon compound bearing at least one silicon-bonded alkoxy or alkoxyalkoxy radical have improved adhesion to a substrate when coated and cured thereon. The compositions can further contain a photosensitizer, a catalyst for the reaction of silicon-bonded alkoxy groups and other components such as fillers, stabilizers, colorants and flame retardants. The compositions are useful as an adhesive or coating for various substrates and in various industries.
Abstract: Silicone-in-water emulsions are prepared wherein the silicone phase as bi-modal and contains at least 25 percent volatile silicone and at least 1 percent high viscosity silicone fluid. The silicone emulsions are particularly useful in skin care compositions. The silicone-in-water emulsions are prepared by a process which is useful to emulsify any high viscosity silicone or mixture of silicones having a viscosity of less than 50 pascal-seconds. The process involves the formation of a rough emulsion followed by the use of low shear, preferably at about room temperature to form a stable emulsion.
Abstract: A fiber-treatment composition based on a microemulsion, having an average particle size not larger than 0.15 micrometers, of a carboxyl-modified organopolysiloxane having a degree of polymerization of form 350 to 2000 and having at least two carboxyl groups in each molecule is characterized by an excellent mechanical stability, dilution stability, and blending stability, and can impart a durable softness, smoothness, wrinkle resistance, and compression recovery to fibrous material without the occurrence of oil spotting. Further stability of the microemulsion can be realized by adding a basic material to the microemulsion to adjust the pH of the microemulsion, preferably to a value of from 6.5 to 9.0.
Abstract: Pressure sensitive adhesives can be protected with a releasable liner having a cured fluoroalkyl silicone coating which contains as little as two percent fluoroalkyl-substituted siloxane units. In a preferred embodiment of this invention silicone pressure sensitive adhesives can be solvent-cast, and even cured, directly onto the release surface of the liner and can be removed from the protective liner with a force of no more than 400 grams per inch. The fluoroalkyl silicone copolymers of this invention are prepared by a process which involves the preparation of a cohydrolyzate of fluoroalkyl-containing and fluoroalkyl-free siloxane units, followed by further polymerization of the cohydrolyzate with other siloxane units.
Abstract: Ultraviolet light-curable compositions which contain a photosensitizer compound and an organosilicon compound which contains (meth)acrylamido-substituted hydrocarbon radicals have improved cure in air when a mercaptoorganosilicon compound is added. The improved compositions are particularly useful as coating compositions for fast-paced operations where the excluding of air from any portion of the curing zone is not desired.
Type:
Grant
Filed:
July 11, 1988
Date of Patent:
May 16, 1989
Assignee:
Dow Corning Corporation
Inventors:
Padmakumari J. Varaprath, Maris J. Ziemelis
Abstract: Aqueous, organic polymer compositions, such as urethane- or acrylic-based coating compositions, can be improved with respect to strength, adhesion, anticorrosion and/or hardness by mixing them with certain aqueous, silicon compound emulsion compositions. For example, silicone resin emulsions provide improved corrosion resistance for urethane coating compositions. The aqueous, silicon compound emulsion composition comprises a primary, a secondary and a tertiary surfactant.
Abstract: Oil-in-water emulsions are provided by a process which involves the mixing of the oil and water in the presence of three nonionic surfactants having certain HLB values. The process is particularly useful for emulsifying an oil having a viscosity exceeding 50,000 centipoise (50 pascal-seconds). Any oil can be emulsified by this process, including hydrocarbon oils like mineral oil and petrolatum, and silicones, including fluids, gums and resins. A particularly useful emulsion prepared by this process is an emulsion of a bi-modal silicone which contains substantial amounts of a volatile silicone and a silicone gum.