Abstract: Pore-free rubber articles are prepared by dip-molding in a dipping medium that includes a vulcanizing agent, then partially-cured by immersing the dip former in a heated liquid bath that is chemically inert. A particularly effective liquid bath is a molten, nitrite free inorganic salt. The partially-cured rubber is then maintained at a desired curing temperature in a low/no oxygen heating oven to complete curing. Alternatively, upon removal from the molten salt bath, the latex film is quenched.

Abstract: Thin-walled rubber articles for use contact with living tissue or with materials to be delivered to living tissue are prepared from aqueous latex of either natural rubber or synthetic cis-1,4-polyisoprene by vulcanization to produce both carbon-carbon and carbon-(sulfur)n-carbon crosslinks, the vulcanization being performed in the absence of any compounding components that contain secondary amine groups or any components that have a tendency to produce nitrosamines. While sulfur activators may be included, it is preferable that no sulfur accelerators at all be included. Thin-walled rubber articles formed from the latex surprisingly exhibit a combination of high tensile strength, high ultimate percent elongation, and low 500% tensile modulus. The process is particularly effective in the manufacture of thin-walled articles from synthetic cis-1,4-polyisoprene.

Abstract: Thin-walled rubber articles for use contact with living tissue or with materials to be delivered to living tissue are prepared from aqueous latex of either natural rubber or synthetic cis-1,4-polyisoprene by vulcanization to produce both carbon-carbon and carbon-(sulfur)n-carbon crosslinks, the vulcanization being performed in the absence of any compounding components that contain secondary amine groups or any components that have a tendency to produce nitrosamines. While sulfur activators may be included, it is preferable that no sulfur accelerators at all be included. Thin-walled rubber articles formed from the latex surprisingly exhibit a combination of high tensile strength, high ultimate percent elongation, and low 500% tensile modulus. The process is particularly effective in the manufacture of thin-walled articles from synthetic cis-1,4-polyisoprene.

Abstract: Pore-free rubber articles are prepared by dip-molding in a dipping medium that includes a vulcanizing agent, then by immersing the dip former in a heated liquid bath that is chemically inert. A particularly effective liquid bath is molten inorganic salt. In addition, the tensile properties of an article of vulcanized rubber can be improved to an unusually effective degree by immersing the already vulcanized article in a solution of a vulcanizing agent to cause the rubber of the article to absorb or imbibe the vulcanizing agent from the solution, and then immersing the rubber and the imbibed vulcanizing agent in a heated liquid bath to increase the degree of vulcanization.

Abstract: Pore-free rubber articles are prepared by dip-molding in a dipping medium that includes a vulcanizing agent, then by immersing the dip former in a heated liquid bath that is chemically inert. A particularly effective liquid bath is molten inorganic salt. In addition, the tensile properties of an article of vulcanized rubber can be improved to an unusually effective degree by immersing the already vulcanized article in a solution of a vulcanizing agent to cause the rubber of the article to absorb or imbibe the vulcanizing agent from the solution, and then immersing the rubber and the imbibed vulcanizing agent in a heated liquid bath to increase the degree of vulcanization.

Abstract: Medical devices of synthetic rubber are prepared from cis-1,4-polyisoprene by dip molding without the use of sulfur containing components. The devices have surprisingly favorable tensile characteristics despite what is known in regard to synthetic cis-1,4-polyisoprene. In addition, the absence of both the proteins present in natural rubber and the sulfur components that are typically used in vulcanization of both natural rubber and cis-1,4-polyisoprene of the prior art renders the devices freely usable without causing the user to suffer Type I or Type IV allergic reactions that typically arise from contact with natural rubber.

Abstract: Rubbery polymers in hydrocarbon solutions are emulsified in aqueous liquids and converted to latices by partitioning the emulsion through a membrane of selective permeability to the hydrocarbon solvent relative to both water and the polymer, thereby removing the hydrocarbon solvent from the emulsion. The foaming that is often associated with removing hydrocarbon solvent from aqueous emulsions by conventional means is thus avoided. Membrane partitioning mechanisms that are useful for this application include those involving both nonporous and microporous membranes, those passing the solvent both as a liquid and as a gas, those drawing off the permeate as both a liquid and a gas, and various combinations of these methods.

Abstract: Gas is generated at a controlled rate from a liquid and solid phase combination that generated gas upon contact, by using diffusive transport of the liquid toward the solid phase surface to prolong the rate of gas generation, with a variety of alternatives for controlling the rate of diffusive transport. This system is useful in infusion devices for delivering medications or other beneficial liquids from a retaining pouch at controlled rates over a prolonged period of time.

Abstract: A method of producing ammonia water (aqua ammonia) by means of desorbing an ammonia laden sorbent, preferably a zeolite molecular sieve or silica gel into water. The method includes placing an activated sorbent material into a sealed vessel, such as a pressure pot, and exposing it to ammonia gas for a period of time. After loading by exposure to ammonia gas, the loaded sorbent is then placed into an air and water tight container for storage. The pouch can be stored for extended lengths of time prior to use of the contents. When ready for use, the contents of the pouch are dropped into a container of water. In one preferred use of the loaded sorbents, the container of water is a toilet bowl. In another preferred embodiment, the container is a separate disposal pouch, such as a small plastic bag capable of holding an ostomy pouch, sanitary napkin or incontinence pad. After use, the ostomy pouch or other device can be made to dissolve by placing the used pouch in ammonia water at a pH of 10.3 or higher.

Abstract: A polymeric casing with a textured (matte-finish) surface is manufactured by dipping a form having external contours conforming to the desired shape of the casing in a solution of a polymer dissolved in one liquid, withdrawing the form from the solution to retain the solution as a film over the form's outer surface, applying a second liquid over the surface of the film, the second liquid being one which is miscible with the first and in which the polymer is insoluble, then solidifying the polymer into a solid film, preferably by solvent evaporation. Application of the second liquid prior to complete drying of the polymer film causes the resulting film to have a matte finish, which has a lubricous effect without the need for added lubricant powders or liquids, particularly when combined with a mandrel which imparts a similar surface finish to the interior of the film.

Abstract: Thin-walled, high-strength prophylactic sheaths fabricated from elastomeric polymer materials are augmented along the border at the open end with a resilient material having a 100% tensile modulus substantially lower, preferably lower by at least about 75%, than that of the sheath material. This facilitates the rolling of the edge and stretching of the sheaths for purposes of application without compromising the high degree of sensitivity in terms of heat and sensation transmission associated with the thin-walled sheaths themselves.