Abstract: A process for preparing a multimodal ethylene copolymer in suspension in a reactor cascade including a first polymerization reactor and subsequent polymerization reactor(s) including polymerizing ethylene and C3-C12-1-alkenes and forming a suspension of multimodal ethylene copolymer particles in a suspension medium made from or containing a diluent, transferring the suspension into a separator, wherein the suspension is separated into multimodal ethylene copolymer particles and recovered suspension medium, purifying part of the recovered suspension medium for producing purified components of the recovered suspension medium, and recycling part of the purified components of the recovered suspension medium to the first polymerization reactor of the reactor cascade, wherein the purified components of the recovered suspension medium recycled to the first polymerization reactor and made from or containing the diluent, undergo catalytic hydrogenation before being introduced into the first polymerization reactor.

Abstract: A process for reducing the level of hydrogen in certain polymerization effluent and recycle streams containing unreacted propylene monomers and hydrogen by contacting the streams with a hydrogenation catalyst so as to convert at least part of the propylene to the corresponding alkane. The process is particularly applicable to the effluent from a slurry polymerization reactor which has been used to produce a polypropylene homopolymer or copolymer having a first molecular weight and at least part of the effluent is to be supplied to a slurry polymerization reactor to produce a polypropylene homopolymer or copolymer having a second, higher molecular weight.

Abstract: A method for preparing a functionalized polymer, the method comprising the steps of (a) polymerizing monomer in the presence of a coordination catalyst to form a polymer, (b) inhibiting said step of polymerizing with a Lewis base, and (c) reacting the polymer with a functionalizing agent.

Abstract: A process for constructing multi-arm star macromolecules with uniform properties, high molecular weight and narrow molecular weight distribution using free radical polymerization is described.

Abstract: An ethylene oligomerization catalyst that oligmerizes ethylene to a series of ?-olefins and that has a Schulz-Flory constant of about 0.75 to 0.995 produces a stream of ?-olefins. This stream is then added to a vessel containing ethylene and a copolymerization catalyst that copolymerizes ethylene and ?-olefins. The resulting branched polyethylene often has good processing properties. The good processing is presumably due to the presence of “long chain branching”. Such polymers are useful for films and other packaging materials, and for molding resins for molding parts such as industrial, automotive or electrical parts.

Abstract: Methods for controlling properties of an olefin polymer using an organozinc compound are disclosed. The HLMI/MI shear ratio of the polymer can be decreased and the Mz/Mw ratio of the polymer can be increased via the addition of the organozinc compound.

Abstract: Reactor assembly for the production of polymers including a fluidized bed reactor (1) comprising a bottom zone (5), a middle zone (6) and an upper zone (7), an inlet (8) for the fluidization gas located in the bottom zone (5), an outlet (9) for the fluidization gas located in the upper zone (7); the outlet (9) for the fluidization gas being coupled with the fluidized bed reactor (1) via inlet (8) via a gas circulation line; means for separation of solids from gas (2) being connected to said gas circulation line; the equivalent cross-sectional diameter of the upper zone (7) being monotonically decreasing with respect to the flow direction of the fluidization gas through the fluidized bed reactor; the middle zone (6) having an essentially constant equivalent cross-sectional diameter with respect to the flow direction of the fluidization gas through the fluidized bed reactor; the equivalent cross-sectional diameter of the bottom zone (5) being monotonically increasing with respect to the flow direction of the fl

Abstract: The invention relates to water-in-water polymer dispersions containing cross-linked cationic polymers, methods for their preparation and their use. The water-in-water polymer dispersions are useful inter alia as flocculants, dewatering (drainage) aids and retention aids in papermaking.

Abstract: Disclosed is a method for carrying out a chemical reaction in a reactor, at least one substance is present in a container that is closed in a gas-tight manner, is introduced into the reactor in said container and is released by breaking open the container. The container is designed such that it breaks open when a specified bursting pressure difference between the internal pressure and external pressure is exceeded. The container is broken open and the substance located in the container is thus released as a result of deliberate application in the reactor of a pressure difference exceeding the bursting pressure difference.

Abstract: A method for producing aqueous polymer dispersions by means of radically initiated emulsion polymerisation, in an aqueous medium, of vinyl ester and ethylene, in series-connected polymerisation reactors, wherein in a first discontinuous polymerisation phase at least some of the reactants are introduced into the first polymerisation reactor and the remainder is added in a metered fashion. The reactor is filled up to more than 90% by volume, and at least 90 wt % of the monomers are reacted; in a second continuous polymerisation phase, the reactants are continuously supplied to the first polymerisation reactor and product is continuously withdrawn, and the product is continuously transferred into a second polymerisation reactor, and in the second polymerisation reactor the polymerisation is continued until at least 98 wt % of the monomers used have reacted.

Abstract: The present invention relates to a process for the preparation of a propylene homo- or copolymer, comprising the following steps: (i) feeding propylene and hydrogen, and optionally one or more comonomers, to a reactor R1, wherein the hydrogen is fed to the reactor R1 in a periodically varying amount, (ii) preparing a first fraction of the propylene homo- or copolymer in the reactor R1 in the presence of a catalyst, (iii) transferring the first fraction to a reactor R2, and (iv) preparing a second fraction of the propylene homo- or copolymer in the reactor R2, wherein the melt flow rate MFR (2.16 kg, 230° C.) of the propylene homo- or copolymer is higher than the melt flow rate MFR (2.16 kg, 230° C.) of the first fraction.

Abstract: The present invention relates to a latex composition containing polymer particles that are polymerized in at least two stages including a first phase polymer having a relatively high molecular weight and a relatively high glass transition temperature, and a second phase polymer having a relatively low molecular weight, a relatively high glass transition temperature, and polymerized from constituent monomers that include a crosslinkable monomer. Paint compositions and architectural coatings containing the latex composition according to the invention are also described herein, as well as substrates coated therewith.

Abstract: A UV-crosslinkable polyacrylate pressure-sensitive adhesive composition having a polyacrylate having photoinitiator units incorporated therein by polymerization and being produced by a free-radical solvent-free polymerization process.

Abstract: The invention relates to a process for the polymerization of vinyl-containing monomers such as, for example, monomeric vinyl halides, in a reaction mixture, in which process less waste is generated.

Abstract: The present invention provides a method for production of a copolymer for photoresists in which the bias of the monomer composition ration is small. This method for production is a method for production of a copolymer for photoresists, which copolymer containing at least two types of repeating units, the method having a supplying step of supplying a monomer solution and a solution containing a polymerization initiator into a polymerization reaction system, wherein the range of fluctuation of the monomer composition ratio of unreacted monomers is within the range between minus 15% and plus 15% or the standard deviation of the monomer composition ratio of unreacted monomers is within 2 in the polymerization reaction system during the period from the start of the polymerization reaction to the end of supplying of the monomer solution.

Abstract: Pressure sensitive adhesive formulations of an acrylic polymer grafted with a macromer are particularly well suited for use in the manufacture of impact resistant articles such as impact resistant glass laminates and products comprising such laminates.

Abstract: Provided are methods of producing polymers with broadened molecular weight and/or composition distribution in a continuous homogeneous polymerization system utilizing reactor temperature gradients, reactor polymer concentration gradients, monomer concentration gradients, catalyst concentration gradients, and combinations thereof in the polymerization reactor. Such methods are particularly suitable when utilizing metallocene catalysts and other single-site catalysts, which generally produce polymers with narrow molecular weight and composition distribution.

Abstract: A process for preparing stable aqueous dispersions of composite particles.

Abstract: The present invention relates to a method of producing water-absorbent resin particles in which a median particle size of primary particles (d) and a median particle size of secondary particles (D) satisfy the relationship of the formula, 5d/3+150<D<5d+150, comprising the steps of: (1) subjecting a water-soluble ethylenically unsaturated monomer to a first-step reversed phase suspension polymerization reaction, in a petroleum hydrocarbon solvent, in the presence of a dispersion stabilizer, to give spherical primary particles having a median particle size (d) of from 30 to 130 ?m; (2) cooling the polymerization reaction solution, to precipitate the dispersion stabilizer; and (3) carrying out a second-step reversed phase suspension polymerization reaction by adding the water-soluble ethylenically unsaturated monomer for the second step to the polymerization reaction solution to agglomerate the primary particles, to give secondary particles having a median particle size (D) of from 200 to 500 ?m.

Abstract: The present invention relates to a process for improving the polymerization of ethylene and one or more optional co-monomer(s) in a polymerization loop reactor characterized in that said process comprises the step of controlling the hydrogen/monomer ratio along the path of the reactor by multiple, spatially separated, feeding of hydrogen along the path of the loop reactor. In particular, the invention provides a process for controlling, and preferably narrowing, the molecular weight distribution of the produced polymer particles. In another aspect, the invention relates to a polymerization loop reactor suitable for the polymerization process of ethylene and an optional olefin co-monomer, wherein the molecular weight distribution of the produced ethylene polymer can be controlled.

Abstract: A method for preparing a functionalized polymer, the method comprising the steps of (a) polymerizing monomer in the presence of a coordination catalyst to form a polymer, (b) inhibiting said step of polymerizing with a Lewis base, and (c) reacting the polymer with a functionalizing agent.

Abstract: A highly active supported chromium catalyst composition for ethylene and other olefins polymerization and also for ethylene copolymerization with efficient incorporation of comonomer, produces polymers with superior spherical morphology, improved bulk density and almost 0% fines. The catalyst composition component includes at least one chromium compound, mainly chromium acetylacetonate, or chromium hexaflouroacetonylacetonate, or chromium diethylmalonate. One magnesium compound, or aluminum compound, metal alkoxy compound and defined polymer particles mainly chloromethylated cross linked styrene-DVB copolymer or polyvinylchloride. The catalyst composition, when used in conjunction with an organoaluminum compound or a mixture of organoaluminum compounds, can be used for olefin polymerization to produce medium or high density polyethylene and copolymers of ethylene with alpha-olefins having about 3 to 18 carbon atoms.

Abstract: The invention relates to a process for the preparation of a copolymer by free radical mass polymerization of a maleic acid monoester derivative with vinyl ester in the presence of an acid having a pKa of less than 1.8. The copolymer is suitable as a dispersant for hydraulic binders.

Abstract: A process for continuously producing water-absorbing polymer particles, comprising polymerization of a monomer solution or suspension on a continuous belt, drying, grinding, classifying and at least partly recycling the undersize obtained in the classification, wherein the recycled undersize is mixed with the monomer solution or suspension.

Abstract: Process for the preparation of low-peroxide crosslinked vinyllactam polymer by free-radical polymerization in the presence of at least one organic substance acting as antioxidant, low-peroxide crosslinked vinyllactam polymer obtainable by this process, and its use.

Abstract: The present invention provides a novel one-step process for preparing an aqueous polymer dispersion by the free radical aqueous emulsion polymerization comprising mixing at least water, a dispersant, and an oil-soluble initiator; raising a temperature from the starting to the end reaction temperature while metering at least ethylenically unsaturated monomers and a water-soluble initiator into a reaction vessel, conducting polymerization of the monomers in the presence of the water-soluble initiator at a temperature up to the end reaction temperature, and when the temperature has reached the end reaction temperature, conducting polymerization by the oil-soluble initiator. The oil-soluble initiator is inactive at the starting reaction temperature and becomes more active as a temperature approaches the end reaction temperature at which the oil-soluble initiator is fully active.

Abstract: Disclosed is a method for preparing polyolefins containing vinylidine end groups from quasiliving carbocationically terminated polyolefin polymers by contacting the quasiliving carbocationically terminated polymer with a suitable nonaromatic heterocyclic ring quenching agent and substituted derivatives thereof.

Abstract: An oil-based ink composition for inkjet recording capable of exhibiting desired properties of drying after print, rubfastness and re-solubility is achieved by performing solubilization on an acrylic resin which is not easily dissolved conventionally. The oil-based ink composition for inkjet printing comprises glycol ether dialkyl ethers as a prime solvent; and an acrylic resin that results from solution polymerization in a solvent of the glycol ether dialkyl ethers by use of a radical polymerization initiator.

Abstract: The purpose of the present invention is to provide a process for producing an olefin polymer, which can produce an olefin polymer having a higher molecular weight by lowering hydrogen concentration efficiently in polymerizing an olefin in the presence of hydrogen by use of a gas phase reaction vessel. There is provided a process for producing an olefin polymer comprising the steps of: using a gas phase reaction vessel; polymerizing an olefin by use of a catalyst for olefin polymerization in the presence of hydrogen; and adding a hydrogenation catalyst to a bed portion in the gas phase reaction vessel.

Abstract: The present invention relates to an improved method for preparing an ethylene-silane copolymer comprising hydrolysable silane groups by radical-initiated polymerisation of ethylene and an olefinically unsaturated silane compound, such as vinyl trimethoxysilane (VTMS). Said method is performed in a multi-zone reactor comprising two or more reaction zones, wherein advantageously essentially all of the silane compound is introduced into the first reaction zone to provide a higher conversion of silane monomer into polymer.

Abstract: A resin for photoresist compositions is disclosed with excellent resolution and line edge roughness characteristics. A photoresist composition and a method for forming a resist pattern using such a resin are also disclosed. The resin has a hydroxyl group bonded to a carbon atom at a polymer terminal, and the carbon atom in the ?-position to the hydroxyl group has at least one electron attractive group.

Abstract: A multistep process comprising the following steps: step a) polymerizing propylene and optionally one or more monomers selected from ethylene or alpha olefins of formula CH2?CHT1, wherein T1 is a C2-C10 alkyl radical in the presence of a catalyst system supported on an inert carrier, comprising: ii) one or more metallocene compounds of formula (I): ii) an alumoxane or a compound capable of forming an alkyl metallocene cation; and optionally iii) an organo aluminum compound; step b) contacting, under polymerization conditions, in a gas phase, propylene or ethylene with one or more alpha olefins of formula CH2?CHT, wherein T is hydrogen or a C1-C10 alkyl radical, and optionally a non-conjugated diene, in the presence of the polymer obtained in step a) and optionally in the presence of an additional organo aluminum compound; provided that an homopolymer is not produced; wherein: the compound of formula (I) is described in the application.

Abstract: The invention provides a continuous-flow process for producing a polymeric material. The process of the invention comprises the steps of: introducing at least two solutions, each comprising one or more reactants, into a microreactor to mix the two solutions to form a reacting solution, wherein the one or more reactants are selected from the group consisting of a monomer, an initiator, a coupling agent, a prepolymer, a macromer, and mixtures thereof; feeding continuously the reacting solution into a flow-through polymerization reactor in a coil form, wherein the flow-through polymerization reactor is capable of providing a residence time sufficient for (co)polymerizing the reactants to form a polymer with a desired polydispersity, wherein the flow-through polymerization reactor is immersed in an ultrasonic bath to minimize or substantially eliminate unwanted high-molecular-weight fractions of the polymer.

Abstract: A method of discharging polymer from a continuously operated polymerization reactor, wherein at least a monomer is polymerized to form polymer particles, the method comprising adjusting the discharge rate of the polymer particles by means of a piston valve having a piston element connected to an actuator, said actuator being able to modulate the piston stroke inside said piston valve.

Abstract: A vinyl-based polymer having a mass average molecular weight of 1500 to 10000, which is prepared by a first step of continuously feeding a material mixture containing a vinyl-based monomer to a continuous tank type first reactor, and polymerizing the vinyl-based monomer under the conditions of a polymerization temperature of 150° to 300° C. and a retention time of 1 to 60 minutes at a rate of polymerization of 50 to 99% to obtain a reaction intermediate mixture; and a second step of feeding a polymerization initiator in the amount of 0.01 to 5 parts by mass based on 100 parts by mass of the vinyl-based monomer and the reaction intermediate mixture to a second reactor, and further polymerizing the vinyl-based monomer under the conditions of a polymerization temperature of 100° to 200° C. and a retention time of 10 to 240 minutes at a rate of polymerization of 80% or more.

Abstract: A process for preparing a water-absorbent resin made from an ?,?-unsaturated carboxylic acid as an essential monomer characterized in that the process comprises allowing a metal chelating agent to be present at any step in the process in an amount of 0.001 to 6 parts by weight, based on 100 parts by weight of the ?,?-unsaturated carboxylic acid; and adding a reducing agent or an oxidizing agent thereto in an amount of 0.001 to 6 parts by weight, based on 100 parts by weight of the ?,?-unsaturated carboxylic acid before initiation of drying and/or during drying of a gelated product containing a water-absorbent resin obtained by polymerization.

Abstract: A multistep process comprising the following steps: step a) polymerizing propylene and optionally one or more monomers selected from ethylene or alpha olefins of formula CH2?CHT1 wherein T1 is a C2-C10 alkyl radical in the presence of a catalyst system supported on an inert carrier, comprising: ii) one or more metallocene compounds of formula (I): ii) an alumoxane or a compound capable of forming an alkyl metallocene cation; and optionally iii) an organo aluminum compound; step b) contacting, under polymerization conditions, in a gas phase, propylene or ethylene with one or more alpha olefins of formula CH2?CHT, wherein T is hydrogen or a C1-C10 alkyl radical, and optionally a non-conjugated diene, in the presence of the polymer obtained in step a) and optionally in the presence of an additional organo aluminum compound; provided that an homopolymer is not produced; wherein: the compound of formula (I) is described in the application.

Abstract: The object of the present invention is to provide a treatment method which deactivates deposits in a reactor and the like in a production process of an ?-olefin low polymer. The present invention relates to that after completion of the production of a low polymer of ethylene in a reactor 10 in the presence of a chromium series catalyst, a hydrocarbon compound solution containing an electron donative compound such as water or alcohol is supplied to the reactor 10 and a heat exchanger 16, thereby deactivating the deposits.

Abstract: A copolymer for semiconductor lithography, comprising at least a recurring unit (A) having a carboxylic acid ester structure whose solubility in alkali increases by the action of an acid and a carboxyl group-containing recurring unit (B), which copolymer is obtained via a step (P) of (co)polymerizing at least a monomer giving a recurring unit (A) and a step (Q) of forming a recurring unit (B) in the co-presence of a recurring unit (A)-containing (co)polymer and/or a monomer giving a recurring unit (A), and an acid. The copolymer is used in production of semiconductor as a resist polymer which is small in roughness, little in development defect and superior in lithography properties such as DOF and the like.

Abstract: In a method for producing an olefin polymer to polymerize olefin by supplying olefin and a catalyst for polymerizing olefin into a vapor-phase fluidized bed reactor, the method includes introducing a fluidity improving agent comprising a compound represented by the following formula into the vapor-phase fluidized bed reactor. [R—O—(AO)m—COO—]nY (wherein, R represents an alkyl group, an alkenyl group or an aryl group, AO represents an alkylene oxide group, m represents the average addition molar number of alkylene oxide, Y represents a hydrogen atom, an alkali metal atom, an alkaline earth metal atom or an ammonium group, and n represents the valence of Y.

Abstract: A resin for photoresist compositions is disclosed with excellent resolution and line edge roughness characteristics. A photoresist composition and a method for forming a resist pattern using such a resin are also disclosed. The resin has a hydroxyl group bonded to a carbon atom at a polymer terminal, and the carbon atom in the ?-position to the hydroxyl group has at least one electron attractive group.

Abstract: A process for producing polymers having at least one high vinyl end segment is provided. The process comprises: (a) forming a living prepolymer high vinyl initiator with a vinyl content greater than about 45% using a vinyl modifier, (b) adding a R1R2R3aluminum or R1R2R3boron compound to nullify the effect of the vinyl modifier, and (c) initiating polymerization of diene monomers using said living prepolymer high vinyl initiator so as to form a polymer product with at least one high vinyl end segment, where R1, R2, and R3 are selected from the group consisting of C1-C12 alkyl, C2-C12 alkene, C2-C12 alkyne, phenyl, and alkyl-substituted phenyl, and may all be identical or may all be separately selected but cannot be H. The polymers having at least one high vinyl end segment may be coupled to produce a polymer having a high vinyl end segment on all ends.

Abstract: The invention relates to water-soluble, preferably powder-form polymer compositions which are obtained by continuous polymerization of at least one unsaturated monomer. At least one parameter that influences the polymerization is varied according to a recurrent pattern. The invention also relates to the use of the inventive polymer compositions and to a method for producing them.

Abstract: There is provided a synthetic resin emulsion comprising polymer particles having a core/shell structure, wherein the shell comprises a copolymer of an unsaturated carboxylic acid and a hydrophilic comonomer, the core comprises a copolymer of a monomer mixture comprising a radically polymerizable main monomer and a radically polymerizable functional monomer, and the monomers constituting the monomer mixture are selected so that the glass transition point (Tg) of the copolymer produced by polymerization is ?20° C. or below, and the synthetic resin emulsion has been produced by adding the monomer mixture for core formation and a pH adjustor to an aqueous copolymer solution, which has not been neutralized, produced by polymerizing the unsaturated carboxylic acid and the hydrophilic comonomer in an aqueous medium, and allowing a polymerization reaction to proceed.

Abstract: A method of polymerizing olefins comprising combining in one embodiment ethylene and optionally one or more ?-olefins with a catalyst composition in a continuous polymerization reactor at a pressure of less than 10,000 kPa; wherein the catalyst composition comprises a hafnocene; and isolating a polyethylene having a density in the range of from 0.930 to 0.975 g/cm3. Also provided is a method of transitioning a continuous polymerization reactor from production of a low density polyethylene to a medium or high density polyethylene. Also provided is a medium to high density polyethylene suitable for injection or rotomolding applications. Also provided is a single catalyst composition suitable for such needs.

Abstract: Aqueous crosslinkable coating composition suitable for anti-graffiti and heavy duty applications comprising: (A) an aqueous polymer emulsion comprising at least one vinyl fluoropolymer which comprises as a polymerized constituent monomer thereof (i) a fluoromonomer(s) having the formula (1) wherein R1 is CH3 or H, R2 is a per-fluorinated C1-5 alkyl group and n is 1, 2, 3 or 4, (ii) a hydroxyl functional monomer(s) and (iii) a carboxylic acid-functional monomer(s) where the vinyl fluoropolymer has a glass transition temperature Tg within the range of from ?50 to 90° C.

Abstract: The present invention relates to a process for controlled radical polymerization using an organosulfur reversible chain transfer agent which consists in preparing polymers having a molar weight of greater than 100 000 g/mol, with a polydispersity index of less than 1.2 for molar weights of less than 200 000 g/mol and of less than 1.4 for molar weights of greater than 200 000 g/mol, with a degree of conversion of monomer of greater than 75% and a polymerization time of less than 8 h, characterized by the control of the flux of initiator radicals in the polymerization medium. The control of the flux of initiator radicals can be achieved by the use of two appropriate polymerization temperatures T1 and T2 or by use of an initiator having a decomposition rate constant which is greater than that of azobisisobutyronitrile at the same temperature.

Abstract: Processes for the living polymerization of olefin monomers with terminal carbon-carbon double bonds are disclosed. The processes employ initiators that include a metal atom and a ligand having two group 15 atoms and a group 16 atom or three group 15 atoms. The ligand is bonded to the metal atom through two anionic or covalent bonds and a dative bond. The initiators are particularly stable under reaction conditions in the absence of olefin monomer. The processes provide polymers having low polydispersities, especially block copolymers having low polydispersities. It is an additional advantage of these processes that, during block copolymer synthesis, a relatively small amount of homopolymer is formed.

Abstract: The present invention provides a processing aid for thermoplastic resin having a weight average molecular weight of 10,000 to 300,000, which is obtained by polymerizing an alkyl (meth)acrylate, or an alkyl (meth)acrylate and another vinyl monomer copolymerizable therewith, in the presence of a mercaptan having an alkyl ester group with C4-20 alkyl group as a chain transfer agent, and/or an organic peroxide having a tertiary-butyl peroxy group as a polymerization initiator.

Abstract: A latex having a reduced amount of 4-phenylcyclohexene is obtainable by reacting A) 30–90% by weight of at least one ethylenically unsaturated monomer; B) 70–10% by weight of a diene; C) 1–10% by weight of ?,?-unsaturated carboxylic acids, carboxylic acid nitriles, carboxylic acid amides, or mixtures thereof; and D) an auxiliary, an additive or mixtures thereof. The reaction follows a gradient regime for components A and B.