Abstract: The process features concurrent feeds into the liquid phase of a prepolymerization reaction mixture. These feeds are: a) separate continuous or substantially continuous feeds of (i) a polymerizable vinylolefin, and (ii) a solution in an organic liquid solvent of a metallocene and an aluminoxane and/or metallocene-aluminoxane reaction product; or b) separate continuous or substantially continuous feeds of (i) a polymerizable vinylolefin, (iii) a metallocene optionally in an organic liquid solvent or diluent, and (iv) an aluminoxane optionally in an organic liquid solvent or diluent; or c) separate continuous or substantially continuous feeds of (i) and (ii) and at least one of (iii) and (iv). Particles of catalytically-active, prepolymerized, self-supported olefin polymerization catalyst composition are formed in the reaction medium. The metallocene used as the feed or in making up the feed has at least one polymerizable olefinic substituent in the molecule.

Abstract: This invention relates to a method and an apparatus for sealing a port of a vessel, which apparatus comprises: (a) a seal for forming a gas-tight seal with the port to close off the port, (b) a chamber; and (c) a chamber sweeping gas for sweeping the chamber.

Abstract: The present invention relates to a process for producing a crystalline synthetic faujasite of the zeolite Y type wherein a relatively small amount of a zeolite Y seed is thoroughly mixed with sodium silicate at ambient temperature to form an activated sodium silicate system and to such activated system, sodium aluminate is added at ambient temperature. The mixture is then heated and reacted with stirring until the desired cyrstalline product is formed. Zeolite Y is filtered out and then dried.

Abstract: An apparatus for reducing the vinyl chloride monomer content of polyvinyl chloride resins suspended as a slurry in an aqueous medium. The polyvinyl chloride-water slurry as produced in a conventional suspension resin autoclave, or a resin-water slurry prepared subsequent to suspension polymerization, is placed in a vessel and heated to a suitable temperature for removal of vinyl chloride monomer from the resin. In this operation, the polyvinyl chloride-water slurry is agitated in a vessel and steam is injected directly into the slurry to rapidly heat the slurry up to a minimum temperature of at least about 180.degree. F. The slurry is cooled immediately, or optionally it can be maintained for a period of time at the selected maximum temperature and then rapidly cooled by applying vacuum to the vessel and condensing the vapor phase removed from the vessel. Dried polyvinyl chloride resin produced by this process has been found to have a vinyl chloride monomer content below a detectable limit of 0.5 ppm.

Abstract: A method for reducing the vinyl chloride monomer content of polyvinyl chloride resins suspended as a slurry in an aqueous medium. The polyvinyl chloride-water slurry as produced in a conventional suspension resin autoclave, or a resin-water slurry prepared subsequent to suspension polymerization, is placed in a vessel and heated to a suitable temperature for removal of vinyl chloride monomer from the resin. In this operation, the polyvinyl chloride-water slurry is agitated in a vessel and steam is injected directly into the slurry to rapidly heat the slurry up to a minimum temperature of at least about 180.degree. F. The slurry is cooled immediately, or optionally it can be maintained for a period of time at the selected maximum temperature and then rapidly cooled by applying vacuum to the vessel and condensing the vapor phase removed from the vessel. Dried polyvinyl chloride resin produced by this process has been found to have a vinyl chloride monomer content below a detectable limit of 0.5 ppm.