Abstract: The present invention relates to polymer mixtures including hydrogel-forming polymers capable of absorbing aqueous fluids and prepared by polymerization of olefinically unsaturated carboxylic acids or derivatives thereof together with copolymers of C2–C8 olefins or styrenes with anhydrides and also their preparation, use and hygiene articles which include same.

Abstract: The present invention relates to a preparation method for acrylonitrile-butadiene-styrene resin by continuous bulk polymerization comprising the following steps of a) preparing a mixed solution of styrene monomers and acrylonitrile monomers by adding 5–10 weight % of the mixture of styrene monomers and acrylonitrile monomers to a reaction solvent; b) preparing a polymerization solution by dissolving butadiene rubber in the above mixed solution of styrene monomers and acrylonitrile monomers; c) polymerizing with a serial injection of the prepared polymerization solution and initiator in a grafting reactor; d) polymerizing the reaction solution of the above c) in a phase inversion reactor by adding 90–95 weight % of the total mixture of styrene monomers and acrylonitrile monomers thereto; and e) polymerizing further the reaction solution of the above step d) at 130–160° C. The resin prepared by the method of the present invention thus has excellent impact strength and gloss.

Abstract: This invention is based upon the discovery that a catalyst system which is comprised of (a) palladium or a palladium compound and (b) a fluorinated alcohol is effective for polymerizing norbornene-functional monomers into polynorbornene-functional polymers. It has been further discovered that this catalyst system is more effective in polymerizing certain norbornene-functional monomers that are difficult to polymerize, such as norbornene ester monomers, than prior art catalyst systems. The activity of the catalyst systems of this invention can be further improved with respect to polymerizing some monomers by including a Lewis acid and/or a ligand, such as a phosphine or a carbene, in the system. In any case, the catalyst systems of this invention offer the advantage of being soluble in a wide variety of solvents, relatively inexpensive, and capable of polymerizing many norbornene-functional monomers that are difficult to polymerize with conventional catalyst systems.

Abstract: The present invention relates to a continuous gas phase process comprising polymerizing one or more hydrocarbon monomer(s) in a fluidized bed reactor in the presence of catalyst system or polymerization catalyst and a condensable fluid for a period of at least 12 hours where the bed temperature is less than the Critical Temperature and the dew point temperature of the gas composition in the reactor is within 25° C. of the bed temperature.

Abstract: The present invention provides a method of producing porous spherical particles, which includes suspension polymerization of a multifunctional monomer having two or more vinyl groups and a vinyl monomer having one vinyl group in an aqueous medium in the presence of a porogen and a distribution stabilizer, wherein the distribution stabilizer is polyvinyl alcohol having a saponification degree of 75 to 85 mol %. According to the method of the present invention, generation of particle agglomerates and large particles can be suppressed and porous spherical particles having a desired average particle size and a narrow particle size distribution can be conveniently produced.

Abstract: This invention provides a graft modified polypropylene polymer which does not contain halogens, is excellent in certain properties such as solubility and can add good adhesiveness and coating ability to crystalline propylene polymer base materials, and a composition containing the same; and in particular, it provides a propylene polymer which contains a propylene polymer main chain having a stereo-block structure containing an isotactic block and a side chain containing a carboxylic acid group, an acid anhydride group or a carboxylic acid ester group, wherein when it is dissolved in toluene to a concentration of 10% by weight at 25° C., the insoluble matter is 1% by weight or less based on the total polymer, and a composition containing the same.

Abstract: A process for polymerizing one or more alpha-olefins of formula CH2?CHT wherein T is a hydrogen atom or a C1–C20 alkyl radical comprising the following steps: a) contacting in a continuous way one or more of said alpha olefins with a metallocene based catalyst system in a loop reactor, wherein: (i) the reaction is carried out in a liquid medium; (ii) the average residence time of the metallocene-based catalyst system is not more than 30 minutes; (iii) the temperature of the loop ranges from 25° to 70° C.; in order to obtain a polymerization degree ranging from 60 to 500 g per gram of catalyst system; b) feeding in continuous the prepolymerized metallocene-based catalyst system obtained in step a) into a polymerization reactor C) polymerizing one or more alpha-olefins, the same or different from the alpha olefins used in step a), in the presence of said prepolymerized metallocene-based catalyst system.

Abstract: Disclosed herein is a method of preparing an EP(D)M elastomer, which includes pre-cooling a reactive solvent to ?80 to ?100° C.; and polymerizing ethylene, at least one higher ?-olefin having 3 to 18 carbons, and selectively, at least one conjugated or non-conjugated diene having 5 to 15 carbons, in the presence of the reactive solvent. According to the method of the current invention, the yield of the EP(D)M elastomer is drastically increased even though a conventional preparation device is used unchanged. Further, methods of controlling the yield of the EP(D)M elastomer and of recovering the EP(D)M elastomer are provided.

Abstract: A process for continuously producing a polymer drag reducing agent (DRA) is described. The process concerns mixing a monomer and a catalyst in at least one continuously stirred tank reactor (CSTR) to form a mixture. The mixture is continuously injected into a volume continuously formed by a thermoplastic material, such as polyethylene. The thermoplastic material is periodically sealed off to form a temporary container or bag. The monomer is permitted to polymerize in the temporary container to form polymer. In one non-limiting embodiment, the polymerization in the bag takes place within an inert, circulating fluid that accelerates heat transfer. The polymer and the temporary container are then ground together, preferably at non-cryogenic temperatures, to produce a particulate polymer drag reducing agent. In one preferred, non-limiting embodiment, the grinding or pulverizing occurs in the presence of at least one solid organic grinding aid.

Abstract: The present invention relates to a mass polymerized rubber-modified polymeric composition comprising a continuous matrix phase of a polymer of a monovinylidene aromatic monomer, and optionally, an ethylenically unsaturated nitrile monomer, and rubber particles produced from a functionalized diene rubber.

Abstract: The present invention concerns a process and an apparatus for continuous polymerisation of olefin monomers in a cascade of polymerisation reactors. According to the process, an olefin monomer is polymerised first in slurry phase in an inert hydrocarbon diluent in at least one loop reactor and then, subsequently, in gas phase in at least one gas phase reactor. According to the invention, a polymer slurry is continuously withdrawn from the loop reactor and optionally concentrated. The concentrated slurry is conducted to a high pressure flash unit in order to remove the remaining fluid phase, and fed to the gas phase reactor. With the process described in this invention, it is possible to produce bimodal polyethylene with good properties. The operation of the process is stable because of the truly continuous operation.

Abstract: A production method of a porous resin or an intermediate therefor, which comprises a step of producing a styrene-acyloxystyrene-divinylbenzene copolymer comprising suspension copolymerization of a styrene monomer, an acyloxystyrene monomer and a divinylbenzene monomer using an organic solvent and water, and a step of converting the styrene-acyloxystyrene-divinylbenzene copolymer to a styrene-hydroxystyrene-divinylbenzene copolymer, wherein a chain transfer agent is added to the suspension copolymerization system.

Abstract: There is provided a process for producing a vinyl chloride-based polymer, in which a suspension polymerization of either vinyl chloride monomer, or a mixture of vinyl chloride monomer and another copolymerizable monomer, is conducted in a polymerization vessel fitted with a reflux condenser, the process including the steps of: (A) adding to the reaction mixture a high-activity, oil-soluble polymerization initiator, with a 10-hour half life temperature of no more than 40° C. at a concentration of 0.

Abstract: A process for the preparation of low branch content polybutadiene comprising: (a) a first butadiene polymerisation stage; (b) treatment of the polymer solution obtained upon completion of stage (a) with a coupling agent selected from: (i) polyunsaturated natural oils; (ii) butadiene and/or isoprene oligomers; (iii) butadiene and/or isoprene co-polymers with vinylarene monomers; the unsaturations present in compounds (i)–(iii) being at least partially substituted with groups selected from epoxides, anhydrides and esters; (c) recovery of the low branch content polybutadiene obtained upon completion of stage (b).

Abstract: A method for transferring polymer within a polymerization system, comprising continuously withdrawing the polymer from the reactor and conveying the polymer from a reactor to a flash chamber via a pressure differential between the reactor and the flash chamber. A method for transferring polymer within a polymerization system comprising conveying the polymer from a reactor to a flash chamber via a pressure differential between the reactor and the flash chamber and purging interstitial gases from the polymer prior to conveying the polymer from the flash chamber to a purge column. A method for transferring polymer within a polymerization system comprising conveying the polymer from a flash chamber directly to a purge column via a pressure differential between the flash chamber and the purge column.

Abstract: The invention pertains to a process wherein initiators and protective colloids are both metered to a polymerization mixture. This manner of metering allows for improved control of the polymerization rate and an improved reactor space-time yield, and the process will render a polymer with a relatively high porosity.

Abstract: There is provided a method for producing a polymer, which is characterized by polymerizing or copolymerizing an organic compound monomer or monomers accommodated in pores of a porous metal complex.

Abstract: This invention discloses a rubbery polymer which is comprised of repeat units that are derived from (1) at least one conjugated diolefin monomer, and (2) 0.

Abstract: A styrene/hydrogenated diene block copolymer characterized in that it has in side chains at least one kind of functional groups selected from the group consisting of a boronic acid group and a boron-containing group capable of converting into a boronic acid group in the presence of water, the content of the functional groups in the copolymer is 100 to 2,000 ?eq/g, and the weight ratio of the styrene units to hydrogenated diene units contained in the copolymer is from 5/95 to 70/30. By thus incorporating a sufficient amount of boron-containing groups, a highly reactive styrene/hydrogenated diene block copolymer is provided.

Abstract: Process for preparing homopolymers of ?-methylstyrene, or copolymers of ?-methylstyrene and comonomers, by anionic polymerization in the presence of an initiator composition, which comprises using an initiator composition in which potassium hydride and at least one organylaluminum compound are present.