摘要:
An aqueous silicone emulsion which crosslinks by a Michael addition reaction, yielding a cured composition upon removal of the water has been prepared. The aqueous silicone emulsion comprises the product formed by mixing an organosiloxane polymer containing at least two Michael acceptor groups per organosiloxane molecule, water, a surfactant and an effective amount of a crosslinker having sufficient reactive hydrogens of a Michael donor per crosslinker molecule. The invention also describes a method for making these silicone emulsions.
摘要:
A crosslinked polysiloxane dispersion comprising a siloxane polymer, polymer mixture, or polymer/solvent mixture, capable of crosslinking via condensation, addition or free radical reactions, and having a viscosity of greater than 5000 mPa.s but less than 500,000 mPa.s, if required, 0.1 to 10 weight parts of a crosslinking agent, and, if required, depending on the nature of the catalyst and silicon cure system, 0.000001 to 10 weight parts of a catalyst, 0.5 to 10 weight parts of a surfactant or surfactant mixture, and 0.5 to 25 weight parts water per 100 weight parts siloxane polymer. Optionally, adhesion promoters, pigments, reinforcing or non-reinforcing fillers, silicone resins, stabilizers, freeze/thaw additives, etc. may also be added to the dispersion.
摘要:
Emulsion copolymerizing a particular crosslinker, i.e., either a siloxane or silazane, with an organic monomer, results in new and novel emulsions. An emulsion can be formed having particles consisting of polymer chains formed from organic monomer. Depending on the crosslinker and reaction conditions, these emulsion polymer chains can be either crosslinked or uncrosslinked. The uncrosslinked polymer chains can be crosslinked at a later point by the addition of a suitable catalyst.
摘要:
An aqueous emulsion which crosslinks by a Michael addition reaction, yielding a crosslinked silicon modified organic composition upon removal of water has been prepared. The aqueous emulsion comprises the product formed by mixing a polymer containing at least two Michael acceptor groups per polymer molecule, water, a surfactant and an effective amount of a crosslinker containing sufficient reactive hydrogens of a Michael donor per crosslinker molecule or a precursor thereto. In order to obtain a crosslinked silicon modified organic composition upon the removal of water, the polymer or the crosslinker must contain at least one silicon atom. The invention also describes a method for making these emulsions.
摘要:
Emulsions prepared using a silicone polyether as the surfactant are stable in an aqueous media in the presence of salts such as electrolytes, alcohols, solvents, and combinations thereof. The emulsions can be prepared by (i) polymerizing an unsaturated monomeric organic compound in water containing the monomer, a silicone polyether, a catalyst, and optional organic surfactants, until a polymer of desired molecular weight is obtained; (ii) by mechanically emulsifying a non-silicon atom containing organic oil in water using a silicone polyether with or without addition of other organic surfactants; and (iii) by mixing and adding a silicone polyether to a previously prepared emulsion.
摘要:
A process for preparing emulsions of silicone gums is disclosed based on using an ethylene oxide/propylene oxide block copolymer as the emulsifier. The emulsions produced by the present process are useful as coatings additives for both water-based and oil-based coatings to obtain improved slip and anti-mar properties. The emulsions may also be used in the manufacture of tires as band ply lubricants. They may also be used in personal care applications.
摘要:
A method and apparatus for making silicone-in-water emulsions comprising high viscosity silicone polymers is provided. In various aspects, polyorganosiloxanes are polymerized into high viscosity silicone polymers then emulsified in a continuous process, wherein the process is carried out using a single apparatus. In some aspects, the provided apparatus is an extruder for polymerizing polyorganosiloxanes into high viscosity silicone polymers and then emulsifying such polymers.
摘要:
Compositions useful for providing water repellent characteristics to substrates contain (i) 0.1-99 percent by weight of a methylhydrogensiloxane; (ii) 0.1-99 percent by weight of a silanol endblocked siloxane; (iii) 0.1-99 percent by weight of a silicone resin; (iv) 0.1-10 percent by weight of at least one surface active agent; and (v) 0.01-5 percent by weight of at least one additive selected from the group consisting of a preservative, an antifoam, a mildewcide, a UV absorber/UV light stabilizer, and a freeze-thaw additive. The balance of the composition to 100 percent by weight is water.
摘要:
A silicone MQ resin based composition provides the oil industry with Fluid Loss Control (FLC) additives for water based drilling muds which are non-damaging. The composition is capable of achieving zero fluid seepage through filter cake, and a short build time for the initial filter cake, while not reducing the return flow of oil from producing formations. The composition is stable in saturated salt at 120° C. and elevated pressures. The composition comprises solid particles of silicone resin with a glass transition temperature more than 70° C., and it contains solid particles of silicone resin with a particle size distribution in which ( ) at least 90 volume percent of solid particles of silicone resin have an average major axis diameter of 40 μm or less than 40 μm, and (ii) at least 10 volume percent of solid particles of silicone resin have an average major axis diameter of 2 μm or less.
摘要:
The tack of a polymeric substrate is reduced by (i) coating a surface of the polymeric substrate with a thermosetting liquid silicone rubber composition, (ii) applying an aqueous suspension of powdered silicone rubber with a mean particle size of 0.1 to 500 micron to the coating of thermosetting liquid silicone rubber composition on the polymeric substrate, and (iii) heating the coated polymeric substrate to cure the thermosetting liquid silicone rubber composition and simultaneously adhere the powdered silicone rubber to the coating on the polymeric substrate.