Abstract: A method for preventing or inhibiting fouling in a gas-phase polyolefin polymerization process. The method includes maintaining the inside surface temperature of the process equipment below the dew point temperature of the gas mixture passing through the equipment.

Abstract: The invention concerns a method for preparing a first generation polymer comprising a step which consists in free radical polymerization of a composition comprising: at least an ethylenically unsaturated monomer, a source of free radicals, at least a dithiophosphoroester compound.

Abstract: Branched copolymers of polypropylene (PP) and polysilanes are prepared by procedures involving melt phase hydrosilylation. Such branched copolymers may be formed in situ during the melt phase hydrosilylation or may be prepared by subsequent processing. The branched copolymers exhibit superior properties.

Abstract: The present invention relates to a method for preparing polymers by gas-phase deposition polymerization, initiated by a zero valent metal and an initiator.

Abstract: Process for treating polyolefin discharged from an olefin polymerization reactor which comprises steps of discharging from a polymerisation reactor a slurry comprising polyolefin and diluent; submitting said slurry to a pressure release such that the diluent is evaporated and a polyolefin/gas mixture is formed; discharging said polyolefin/gas mixture into a collecting vessel; controlling a level of settled polyolefin in the collecting vessel; discontinuously transferring the polyolefin/gas mixture in the collecting vessel into a concentrating vessel; and discharging said concentrator vessel in such a way that said polyolefin/gas mixture is transferred into the hydrocarbon purge bin. Embodiments also comprise the use of two interconnected concentrator vessels and the optimized recovery of the diluent from the purge bin.

Abstract: Polymer fractions such as polyethylene fractions can be produced that have a PDI less than about 2.3 and a Mw greater than about 1,000,000 g/mol, 3,000,000 g/mol, or 6,000,000 g/mol. Such polyethylene fractions are separated from a UHMWPE parent polymer by first dissolving the parent polymer in a relatively good solvent. The conditions employed for such dissolution are selected to reduce the degradation of the parent polymer. The resulting parent solution is transported into a fractionation column in which a support is disposed. The fractionation column is thereafter operated at conditions effective to form a precipitate on the support comprising the desired polyethylene fraction. The polyethylene fraction may then be recovered from the fractionation column by repeatedly displacing a solvent/non-solvent mixture into the column to dissolve the polyethylene fraction. The relative concentrations of the solvent and the non-solvent are based on a solvent gradient profile of the polyethylene parent polymer.

Abstract: A process for producing a cycloolefin addition polymer in which one or more cycloolefin monomers can be (co)polymerized by addition polymerization with a small palladium catalyst amount to produce a cycloolefin addition (co)polymer while attaining high catalytic activity. The process for cycloolefin addition polymer production is characterized by addition-polymerizing one or more cycloolefin monomers comprising a cycloolefin compound represented by a specific formula in the presence of a multi-component catalyst comprising (a) a palladium compound and (b) a specific phosphorus compound.

Abstract: An insulating material comprising a cycloolefin polymer, specifically, an interlayer insulating material for a high-density assembly board having interlayer-connecting via holes at most 200 ?m in diameter, comprising a cycloolefin polymer containing at least 50 mol % of a repeating unit derived from a cycloolefin monomer; a dry film formed from a curable resin composition comprising a polymer having a number average molecular weight within a range of 1,000 to 1,000,000 as measured by gel permeation chromatography, and a hardener; and a resin-attached metal foil obtained by forming a film of a cycloolefin polymer on one side of a metal foil. Laminates, multi-layer laminates and build-up multi-layer laminates making use of these materials, and production processes thereof.

Abstract: There is provided a racing tire improving grip performance, processability and rubber strength at a high temperature in highly good balance and a rubber composition capable of producing a tread having thereof. A rubber composition comprising 70 to 150 parts by weight of carbon black with a nitrogen adsorption specific area of 100 to 300 m2/g based on 100 parts by weight of a rubber component comprising a solution polymerization styrene-butadiene rubber satisfying the formula below: (Vinyl content)?100?2×(styrene content), 30 to 170 parts by weight of a softener and 1 to 30 parts by weight of a compound satisfying the general formula (1): —(R—Sx)n—??(1) (wherein R is —(CH2—CH2—O)m—CH2—CH2— , x is an integer of 3 to 6, n is an integer of 10 to 400 and m represents an integer of 2 to 5.).

Abstract: Olefinic interpolymer compositions comprising the olefinic interpolymer, residuals from a transition metal catalyst and boron containing activator package, and a charge dissipation modifier and methods for making them. The compositions have dissipation factors that are at least 50% less than the corresponding olefinic interpolymer compositions which have not been treated with charge dissipation modifiers. The compositions are useful in wire and cable applications.

Abstract: Flame retardant crosslinkable polyolefin compositions useful for the production of films, sheets and membranes are provided. The compositions are comprised of ethylene-silane copolymer, plastomer, flame retardant filler and, optionally, silanol condensation catalyst.

Abstract: The invention provides for a process to produce polymers utilizing a hydrofluorocarbon diluent.

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 0.1 mol/L in benzene, for a specified time within a period from the commencement of heat removal using the reflux condenser through to completion of the polymerization, and (B) adding an antioxidant either continuously or intermittently to the reaction mixture at least during the period from the commencement of addition of the high-activity, oil-soluble polymerization initiator through to completion of that addition.

Abstract: The base material for pressure-sensitive adhesive tape or sheet is constituted of a polyolefin based resin as the major component and is obtained by rolling by means of a calender having a measure capable of individually changing the rotational speed of each calender roll. Examples of the measure capable of individually changing the rotational speed of each calender roll include a measure provided with motors capable of individually driving their respective calender rolls and a measure provided with speed regulators capable of individually regulating their respective calender rolls. It may be employed that the number of calender rolls is four and that the roll arrangement is in the reverse L shape. It is preferable that the base material for pressure-sensitive adhesive tape or sheet contains an inorganic compound together with the polyolefin based resin.

Abstract: The disclosure is directed to a partially hydrogenated ring-opened polynorbornene and a process for making the same. The ring-opened polynorbornene is low in birefringence, high in wavelength dependency about birefringence and excellent in transparency and heat resistance.

Abstract: The present invention is directed to a free radical control agent of the structural formula: wherein R1 is a divalent alkyl group of 1 to 12 carbon atoms, R2 and R3 are each independently hydrogen or an alkyl group of 1 to 12 carbon atoms, and R4 is —OH or —COOH, with the proviso that the total carbon atoms of R1, R2, and R3 is no greater than 12; and wherein Y represents a functional group that is capable of activating a vinylic carbon toward free radical addition.

Abstract: A process for producing an olefin-based copolymer, which comprises copolymerizing at least one olefin selected from the group consisting of ethylene and straight chain ?-olefins, and a vinyl compound (I) and a polyene (II) described below: Vinyl compound (I); a vinyl compound represented by the general formula CH2?CH—R, wherein the substituent R is a saturated hydrocarbon group and steric parameters Es and B1 of the substituent R are respectively ?1.64 or less and 1.53 or more; and Polyene (II); a compound having two or more of ethylene bonds and at least one combination of two ethylene bonds in which those are bonded to each other through at least three carbon atoms.

Abstract: A continuous polymerization process for producing reactive polymers comprises continuously charging into a first reaction zone at least one functional monomer and polymerizing the monomers to produce a first polymeric product having at least one functional group. This first polymeric product is then continuously directly charged into a second reaction zone together with at least one modifier reactant having a functional group that is complementary to the functional group of the first polymeric product. At least a portion of the modifier reactant reacts with at least one of the functional groups of the first polymeric product to produce a second polymeric product which incorporates at least a portion of the modifier reactant, such that the second polymeric product is a reactive polymer.

Abstract: Novel copolymers, including block copolymers, which comprise: (a) a plurality of constitutional units that correspond to one or more olefin monomer species and (b) a plurality of constitutional units that correspond to one or more protected or unprotected hydroxystyrene monomer species.

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.