摘要:
A controlled release composition comprising an adsorbent polymer, an active agent, and a release retardant is disclosed. The composition has an improved ability to release the active agent over an extended time period.
摘要:
The present invention is directed to a porous polymer microparticle, in the form of broken spheres, open to a porous oleophilic interior surface area, having a high oil and water absorbency and an apparent bulk density of about 0.008 to about 0.1 grams/cc. The preferred method of the present invention comprises the steps of:dissolving at least one, and preferably at least two, polyunsaturated monomers along with an effective amount of an organic polymerization initiator in a water-immiscible organic solvent to provide a monomer mixture;adding the monomer mixture to an aqueous solution, preferably having an effective amount of a suspension stabilizer dissolved therein, to form an organic/aqueous biphasic liquid system;vigorously agitating the biphasic liquid system at a rate sufficient to cause the water-immiscible organic phase to be suspended as microdroplets in the aqueous phase;continuing vigorous agitating during polymerization of the monomers in the suspended microdroplets to produce a microporous polymer microparticle; andseparating the microporous polymer microparticle from the organic solvent to produce a microporous and oil sorbent polymer microparticle having a mean unit diameter of less than about 50 microns and a total sorptive capacity for mineral oil that is at least about 72% by weight, preferably at least about 90% by weight dry polymer basis.
摘要:
A method is described of producing a mixture of silicone polyethers from a mixture of at least two alkenyl ether terminated organic oxyalkylene compounds having different molecular weights and an organosilicon compound having at least two hydride substituents. In an alternate embodiment, an organocyclosilazane is used, and either alkyl or alkenyl ether terminated organic oxyalkylene compounds can be employed. The mixtures have utility in the conditioning of skin.
摘要:
A process of decontaminating a surface contaminated with a toxic chemical agent in which there is applied to the contaminated surface, a macroporous cross-linked hydrophobic copolymer containing an agent which is a decontaminant for the toxic chemical agent present on the surface. The decontaminant can be a chemical neutralizer such as sodium hydroxide; lithium hydroxide; concentrated bleach; and mixtures of diethylene triamine, 2-methoxy ethanol, and sodium hydroxide, for example.
摘要:
A method for modifying or treating solid particles which includes the steps of: (a) forming a gelled mixture by mixing either simultaneously or sequentially in any order: (1) hollow microspheres each comprising a deformable polymeric shell having entrapped therein an expandable fluid, (2) a polar organic solvent capable of swelling but not dissolving the polymeric shells of the hollow microspheres, and (3) solid particles, wherein micro-channels are formed in the swelled polymer shells to allow entry of the solid particles into the hollow microspheres and exit of the expandable fluid therefrom, thereby forming microspheres that each comprises a collapsed polymeric shell in a gelled state and has one or more of said solid particles entrapped therein; (b) removing the expandable fluid and the polar organic solvent from the gelled mixture; and (c) coating the microspheres thus-produced with a film-forming material to form a liquid-impermeable membrane thereon.
摘要:
The present invention relates to topical compositions containing solid particles that are stabilized via entrapment by microspheres and methods for making the same. Each of the microspheres contains a collapsed polymeric shell that has entrapped therein one or more solid particles. The solid particles are preferably formed of zinc oxide or titanium dioxide or both, which can readily be used either alone or in combination with other sunscreen agents to form sunscreen compositions of broader UV protection spectrum and enhanced photostability.
摘要:
The present invention is directed to a porous polymer micro-particle, in the form of broken spheres, open to a porous oleophilic interior surface area, having a high oil and water absorbency and an apparent bulk density of about 0.02 to about 0.1 grams/cc. The preferred method of the present invention comprises the steps of:dissolving at least one and preferably at least two polyunsaturated monomers along with an effective amount of an organic polymerization initiator in a water-immiscible organic solvent to provide a monomer mixture;adding the monomer mixture to an aqueous solution, preferably having an effective amount of a suspension stabilizer dissolved therein, to form an organic/aqueous biphasic liquid system;vigorously agitating the biphasic liquid system at a rate sufficient to cause the water-immiscible organic phase to be suspended as micro-droplets in the aqueous phase;continuing vigorous agitating during polymerization of the monomers in the suspended micro-droplets to produce a microporous polymer micro-particle; andseparating the microporous polymer micro-particle from the organic solvent to produce a microporous and oil sorbent polymer micro-particle having a mean unit diameter of less than about 25 microns and a total sorptive capacity for mineral oil that is at least about 72% by weight, preferably at least about 80% by weight dry polymer basis.
摘要:
The present invention is directed to a porous terpolymer microparticle having a high oil absorbency. The method of the present invention comprises the steps of: dissolving butyl methacrylate, allyl methacrylate, and an ethylene glycol dimethacrylate in a mole ratio of about 1:3 to 5:5 to 7 respectively, along with an effective amount of oil soluble polymerization initiator in a volatile and a substantially water immiscible organic solvent to provide a monomer mixture; adding the monomer mixture to a larger volume of an aqueous solution having an effective amount of a suspension stabilizer dissolved therein to form an organic/aqueous biphasic liquid system; vigorously stirring the biphasic liquid system at a rate sufficient to cause the water immiscible organic phase to be suspended as microdroplets in the aqueous phase; allowing polymerization to occur in the suspended microdroplets to produce a microporous terpolymer microparticle therein; and separating the microporous terpolymer microparticle from the volatile and substantially water immiscible organic solvent to produce a microporous and oil sorbent terpolymer microparticle characterized by having a mean diameter of less than 25 microns and a total sorption capacity for mineral oil that is 72% by weight or greater. The present invention is further directed to a microporous and oil adsorbent microparticle comprising a terpolymer of butyl methacrylate, allyl methacrylate and an ethylene glycol dimethacrylate in a mole ratio of 1:3 to 5:5 to 7 respectively, the microparticle characterized by having a mean unit diameter of less than 25 microns and a total sorption capacity for mineral oil that is 72% by weight or greater.
摘要:
The present invention is directed to an improved process for producing water-soluble and water-insoluble carboxylic acid polymers and copolymers. The process comprises the steps of polymerizing a carboxylic acid monomer, and a polyfunctional cross-linker monomer in a second embodiment, in an effective molar ratio, in a silicone solvent under an inert atmosphere in the presence of an effective amount of an initiator. The preferred copolymer of the second embodiment includes acrylic acid as the carboxylic acid monomer and a lauryl methacrylate and/or stearyl methacrylate as a comonomer. The resulting copolymers have new and unexpected tolerance to salt-containing water when mixed therewith.
摘要:
The present invention is directed to an improved process for producing a viscosifying polymer. The process of the present invention comprises the steps of copolymerizing a carboxylic acid monomer and a polyfunctional cross-linker monomer in an effective mole ratio in a silicone solvent under an inert atmosphere in the presence of an effective amount of an initiator to form a viscosifying polymer that in a 0.5% by weight aqueous mucilage exhibits a viscosity of about 50,000 to 300,000 cps. The present invention is further directed to a viscosifying copolymer comprising a cross-linked copolymer of a carboxylic acid monomer and a polyfunctional cross-linker monomer, the viscosifying copolymer characterized in that a 0.5% by weight aqueous mucilage of the viscosifying copolymer exhibits a viscosity of about 50,000 to 300,000 cps. A preferred viscosifying copolymer includes acrylic acid as the carboxylic acid monomer and allyl methacrylate monomer as the polyfunctional cross-linker.