Abstract: A method for inhibiting polymer build-up in a recycle line and a heat exchanger during a polymerization process of one or more alpha olefins, particularly sticky polymers, which method comprises introducing as an antifouling an alcohol having 1 to 10 carbon atoms, an alkyl or cycloalkyl ether having 2 to 20 carbon atoms, or a mixture thereof at one or more locations in the recycle gas line in an amount sufficient to inhibit polymer buildup.

Abstract: Telecheles are prepared by reacting, preferably, polyfunctional, living polymers obtained by anionic polymerization with a functionalizing agent by a process in which the reaction is carried out while stirring with a stirrer having knife-like blades as stirring elements, the latter being inclined relative to their plane of movement and passing over essentially the complete space occupied by the reaction mixture.

Abstract: A process for reducing trace levels of metallic impurities in cyclized polyisoprene resin is disclosed. The process reduces trace levels of metallic impurities in cyclized polyisoprene resin by washing an impure organic solvent/cyclized polyisoprene resin solution at least once with a heated aqueous acidic solution, and subsequently washing the resin at least once with heated water.

Abstract: Process for preparing an ultrahigh molecular weight linear polyethylene (UHMWLPE) by heating the material to above 280.degree. C. at atmospheric pressure in an inert environment. The treated polymer is then gradually cooled in this same atmosphere.

Abstract: A topsheet for use in body fluid absorptive articles is so improved that collapse and clogging of liquid passages therein may be reliably avoided. The topsheet includes an upper sheet, provided with skin-contacting areas and liquid passages, and a lower sheet provided with skin-non-contacting areas, areas welded to the liquid passages, and exposed areas. The exposed areas are welded to each of the liquid passages around lower openings thereof so as to protect the liquid passage against collapse and clogging. The exposed areas define a skin-contacting surface which rises up into each of the liquid passages without extending above the upper surface of the skin-contacting areas. The upper sheet cooperates with the lower sheet to define cavities extending in the direction of the topsheet thickness.

Abstract: A polymerization apparatus, comprises a polymerization vessel, a reflux condenser installed outside the polymerization vessel and a pipe connected between the reflux condenser and a wall of the polymerization vessel with an end thereof opening into a gaseous phase region inside the polymerization vessel, for returning the liquid condensate to the polymerization vessel, wherein said end projects from an inner surface of the wall of the polymerization vessel into the gaseous phase region. In polymerizing a monomer having an ethylenically unsaturated double bond using the polymerization apparatus, the quantity of heat removed by the reflux condenser is increased stepwise or continuously with progress of the polymerization, such that not less than 20% of the total reaction heat generated during the whole course of the polymerization is removed by the reflux condenser. With 100 or more repeated polymerization runs, polymer scale deposition inside the vessel is minimal even below the pipe end.

Abstract: An ice molding apparatus includes a first mold assembly which includes a first hollow chamber portion and which includes a spike assembly which projects inward from a wall of the first hollow chamber portion. The spike assembly includes a distal end adapted to support a quantity of solid material. The first mold assembly includes a first joint member adapted to connect to a second mold assembly. The second mold assembly includes a second hollow chamber portion which includes a filler channel adapted for passing a quantity of liquid water therethrough into the second hollow chamber portion and to fill up the first hollow chamber portion with water. The second mold assembly includes a second joint member adapted to connect to the first joint member, such that the first hollow chamber portion and the second hollow chamber portion form a combined interior mold chamber. The distal end of the spike assembly is located adjacent to a center portion of the combined interior mold chamber.

Abstract: An air oil separator adapted for attachment to a dry sump type oil pump incorporates a novel centrifuge and air ducting system. The centrifuge is formed of two disks axially spaced on a hollow rotatable shaft with the shaft having small air passages located between the disks that extend radially through to a hollow interior of the shaft. An air duct couples an open end of the centrifuge shaft to an air outlet for exhausting air from the shaft interior to the upper air side of the oil sump. Axially rotating at high speed the centrifuge separates air from inputted oil by throwing the oil to the outer reaches of the housing where the oil exits through an outlet and the separated air is exhausted through the shaft and duct.

Abstract: A process for controlling the particle growth of a polymer in a gas phase polymerization reaction by using an inert particulate material and an unsupported liquid polymerization catalyst.

Abstract: A fluidized bed polymerization process in which a central mixing element sweeps the interior of the bed. The mixing element contains agitator arm which pass adjacent to the reactor walls and a have a perforated surface. Gas is directed to the central mixing shaft and distributed to the agitator arms.

Abstract: A toroidal semifinished product (5) made of raw elastomeric material is semivulcanized in a semivulcanization chamber (4) defined between two half-molds (2, 3) disposed close to each other. A pressure, preferably equal to the pressure exerted by the gases generated in the semifinished product (5), is created in the mold (1a). The half-molds (2, 3) are moved apart from each other and pressure in the mold is gradually reduced, thereby giving rise to the expansion and consequent transferring of the semifinished product (5) from the semivulcanization chamber (4) to a surrounding final vulcanization chamber (6). When the inner diameter of the semifinished product (5) is larger than the inner diameter of the final vulcanization chamber (6), said chamber is closed at its inner circumferential edge and then, after possible pressure increase in the mold, at its outer circumferential edge, in order to integrally enclose the semifinished product and enable completion of the vulcanization process.

Abstract: An arrangement for producing a molded concrete article which has a surface including zones at varying levels. The arrangement includes three groups of punches defining respective impression depths into the concrete article, and a molding device including three head plates, each of which is connected to a corresponding one of the groups of punches. An upper head plate is connected to a group of punches having a deepest impression depth. A lower head plate disposed below the upper head plate is connected to a group of punches having a shallowest impression depth.

Abstract: A vinyl chloride polymer is produced by subjecting vinyl chloride or a monomer mixture made up mainly of vinyl chloride to suspension polymerization in an aqueous medium using a polymerization apparatus equipped with a polymerization vessel. The polymerization apparatus used comprises a polymerization vessel (1) having a substantially cylindrical inner space, said inner space of said polymerization vessel being provided with a plurality of baffles (5) comprising vertically extending pipes, and serpentine pipelines (6) each of which is placed between two adjacent baffles and is extended in a serpentine fashion along the polymerization vessel inner wall from the lower part to the upper part of the polymerization vessel, and a refrigerant being passed through said baffles and said serpentine pipelines. High-cooling performance can be obtained, a high-speed reaction in a large-sized polymerization vessel becomes possible, and a stable polymerization reaction can be carried out.

Abstract: The present invention relates to a process for efficiently purifying a styrenic polymer which comprises adding a poor solvent alone or in combination with a swelling agent to a syndiotactic polystyrene produced by the use of a catalyst comprising (A) an aluminoxane or a coordination complex compound comprising a cation and an anion in which a plurality of radicals are bonded to a metal and (B) a transition metal compound, and treating the polystyrene under a controlled water content of 15 to 10,000 ppm to simultaneously carry out deactivation and deashing. The above process can efficiently remove residual metals without using a deashing agent and afford a highly pure high-grade crystalline styrenic polymer excellent in color tone.

Abstract: This invention discloses a process for preparing a latex which is particularly beneficial for utilization in manufacturing high performance masking tape, which comprises the seqential steps of (1) terpolymerizing a vinyl aromatic monomer, an alkyl acrylate monomer, and an alkyl propenoic acid monomer in an aqueous polymerization medium by free radical polymerization to produce a seed polymer latex; (2) neutralizing the seed polymer latex to a pH of about 6 to about 9 by the addition of an alkali; (3) adding additional vinyl aromatic monomer and alkyl acrylate monomer to the neutralized seed polymer latex; and (4) allowing the additional vinyl aromatic monomer and alkyl acrylate monomer to polymerize in a second polymerization step to a solids content of about 30% to about 50% to produce the latex which is particularly beneficial for utilization in manufacturing high performance masking tape.

Abstract: A polymerization method used, particularly, in suspension polymerization of vinyl chloride, comprising a polymerization vessel (1) having a substantially cylindrical inner space, said inner space of said polymerization vessel being provided with a plurality of baffles (5) comprising vertically extending pipes, and a vertically continuously extending coil (6), and a refrigerant being passed through said baffles and said coil. High-cooling performance can be obtained, a high-speed reaction in a large-sized polymerization vessel becomes possible, and a stable polymerization reaction can be carried out. A high-quality and uniform polymer that has few fish eyes and has a high bulk specific gravity can be obtained.

Abstract: A process for polymerizing olefins using a fluidized bed, in which the monomer entry point is located at a point above the bed height. A pre-polymerization step can be conducted using a Z/N catalyst along with an alkane diluent, and resultant liquid phase is introduced into the fluidized bed above the bed height. The process may use several reactors in series arrangement.

Abstract: A modular wall form assembly includes two upright wall form panels, a bridging plate interposed removably between the wall form panels, and a plurality of coupling devices for connecting securely the wall form panels and the bridging plate. Each of the coupling devices includes at least three horizontally aligned coupling seats mounted respectively on the rear sides of the wall form panels and the bridging plate, and a T-shaped coupling lever. Each of the coupling seats is formed with a rectangular hole and a notch that is located on a longer side of the rectangular hole and that extends to the rectangular hole. The notch has a width shorter than the length of the longer side of the rectangular hole. The coupling lever has a handle that is transversely aligned with respect to a coupling portion. The coupling portion has a cross section that corresponds in size with the rectangular holes of the coupling seats.

Abstract: Thermosetting resin particles having a narrow particle size distribution useful for powder coating application are produced by the steps of (a) providing a first water-soluble polymer having a cloud point within the range between 30.degree. C. and 90.degree. C. and a second water-soluble polymer not having any cloud point; (b) preparing an aqueous suspension in which an organic solvent-containing, liquid thermosetting resin composition is suspended as primary particles of oil droplets in an aqueous suspension medium containing the first and second water-soluble polymers, (c) heating the suspension to a temperature higher than the cloudy point to allow the oil droplets to agglomerate into secondary particles of larger particle sizes, (d) removing the organic solvent contained in the particles during or after step (c) and optionally (e) recovering the particles.

Abstract: The present invention provides a suspension polymerization method for producing a polymerized particle having cavities in the particle.