Abstract: A positive electrode active material, a method for producing the same, and a positive electrode and a lithium secondary battery in including the same are disclosed herein. In some embodiments, a method of producing a positive electrode active material includes mixing a lithium transition metal oxide and a carbon-based material having a hollow structure to form a mixture, and mechanically treating the mixture to form a carbon coating layer on the surface of the lithium transition metal oxide, wherein the carbon-based material has a chain shape, and has a specific surface area of 500 m2/g or greater, a graphitization degree (ID/IG) of 1.0 or higher, and a dibutylphthalate (DBP) absorption of 300 mL/100 g or greater.

Abstract: An object of the present disclosure is to provide a polymer exhibiting reduced heat generation in a low strain region. To achieve the object, the present disclosure provides a multi-component copolymer, comprising a non-conjugated olefin unit, a conjugated diene unit, and an aromatic vinyl unit, characterized in that: a ratio [(C100-120/C0-1000)×100] of crystallinity (C100-120) derived from the non-conjugated olefin unit at 100-120° C. with respect to crystallinity (C0-100) derived from the non-conjugated olefin unit at 0-100° C., as measured by a differential scanning calorimeter (DSC), is 23% or less.

Abstract: To provide a statistical copolymer containing a chloroprene monomer unit and an unsaturated nitrile monomer unit which has a satisfactory oil resistance. A method for producing a statistical copolymer containing a chloroprene monomer unit and an unsaturated nitrile monomer unit includes a step for conducting continuous addition or 10 cycles or more of intermittent portionwise addition of the chloroprene monomer after initiation of a polymerization reaction is provided. A rubber composition using a statistical copolymer according to the invention or a vulcanized molded article containing the rubber composition is excellent in terms of oil resistance, mechanical strength, compression set at a low temperature and flex fatigue resistance.

Abstract: It is an object of the present invention to provide an electrode capable of maintaining superior capacity retention without destruction of an electrode structure, even in the case of using an active material including silicon.

Abstract: A polypropylene composition made from or containing: A) from 50 wt % to 90 wt %; of a propylene homopolymer; B) from 10 wt % to 50 wt %; of a copolymer of propylene having from 30.0 wt % to 70.0 wt %, of ethylene derived units, based upon the total weight of the copolymer; the sum of the amount of component A) and B) being 100; the polypropylene composition having: i) an intrinsic viscosity of the fraction soluble in xylene at 25° C. between 2.2 to 4.0 dl/g; ii) a MFR L (Melt Flow Rate according to ISO 1133, condition L, at 230° C. and 2.16 kg load) from 0.5 to 100 g/10 min; iii) a xylene soluble fraction ranging from 20 wt % to 50 wt %, based upon the total weight of the polypropylene composition; wherein the polypropylene composition being obtained by a polymerization process wherein the catalyst system contains bismuth.

Abstract: The present invention provides a hydrophobic alkali soluble emulsion comprising a polymer obtainable by polymerization with the following monomer components: a) from 40 wt. % to 50 wt. %, based on the total weight of the polymer, of an ?,?-ethylenically unsaturated carboxylic acid monomer; b) from 40 wt. % to 50 wt. %, based on the total weight of the polymer, of an ?,?-ethylenically unsaturated nonionic monomer; c) from 5 wt. % to 8 wt. %, based on the total weight of the polymer, of a nonionic macromonomer; and d) from 1 wt. % to 3 wt. %, based on the total weight of the polymer, of a methyl polyglycol acrylic acid ester.

Abstract: Provided is a copolymer for lithography containing a monomer containing an acid leaving group and a monomer not containing an acid leaving group, in which N(v1)/Nave is from 1.01 to 1.09 and all of N(v2)/Nave, N(v3)/Nave, and N(v4)/Nave are from 0.95 to 1.05 when, among five fractions obtained by dividing an eluate providing a peak according to the copolymer in an elution curve obtained by GPC in order of elution so as to have an equal volume, ratios of monomer units containing an acid leaving group among the total monomer units constituting a copolymer included in the respective fractions from the first which is eluted earliest to the fourth are denoted as N(v1) mol % to N(v4) mol %, respectively, and the ratio of the monomer unit containing an acid leaving group among the total monomer units constituting a copolymer included in the sum of the five fractions is denoted as Nave mol %.

Abstract: A method for producing a polymer is provided. The polymer improves variations in the content ratio and molecular weights of a copolymer's constitutional units, solvent solubility, and the sensitivity of a resist composition using such a polymer. The method includes polymerizing two or more monomers while adding with a polymerization initiator to obtain the polymer, feeding a first solution containing first composition monomers in an initial polymerization stage, and starting dropwise addition of a second solution containing second composition monomers after or simultaneously with the feeding of the first solution. The second composition is equal to a target composition ratio of the polymer to be obtained. The first composition is calculated in advance based on a target composition ratio and the reactivity of the monomers. The above dropping rate is set to high.

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: Provided is a process for preparing polystyrene having a weight average molecular weight (Mw) in the range of 120,000-160,000 g/mol, a polydispersity in the range of 4-6 and a melt flow rate of at least 40 g/10 minutes by feeding styrene into a reaction system through which the styrene passes as a component of a reaction mixture as it is polymerized, the reaction system including an initial reaction zone (100) and a downstream reaction zone (200), comprising the steps of: polymerizing styrene in the initial reaction zone to form polystyrene having a Mw of greater than 300,000 g/mol and a polydispersity in the range 1.5-2.5, 10-30 wt. % of the styrene fed to the initial reaction zone being polymerized there, —and polymerizing styrene remaining in the reaction mixture in the downstream reaction zone, a chain transfer agent being mixed with the reaction mixture at the commencement of this reaction zone and optionally at one or more additional locations within this reaction zone.

Abstract: Method for the preparation of a sticky high impact heterophasic polypropylene (HECO) in a reactor facility comprising in series (i) a first reaction system, (ii) a first conveying line connecting the first reactor system with a second reactor system comprising an outlet, (iii) a second conveying line connecting the outlet with a purge bin comprising a feeder, and (iv) a conveying system being connected with the feeder, and the preparation of said heterophasic polypropylene (HECO) comprises the steps in the order of (a) producing in said first reactor system the polypropylene matrix (M), (b) transferring at least a part of said polypropylene to said second reactor system via the first conveying line, (c) producing in said second reactor system the elastomeric copolymer obtaining the heterophasic polypropylene (HECO), (d) discharging said heterophasic polypropylene (HECO) from said second reactor system via the outlet, (e) transferring said discharged heterophasic polypropylene (HECO) via the second conveying l

Abstract: The present invention provides a method for preparing a water soluble polymer, which comprises: a first step of polymerizing: (a) 60 to 99.5 mol % of at least one selected from acrylamide and methacrylamide, (b) 0.5 to 20 mol % of at least one selected from ?,?-unsaturated monocarboxylic acid, ?,?-unsaturated dicarboxylic acid and salts thereof, and (c) 1 to 20 mol % of at least one selected from a water soluble cationic monomer and a salt thereof, (d) 0.01 to 1 mol % of a chain transfer agent, and (e) 0.005 to 5 mol % of a crosslinkable monomer, in the presence of a persulfate-based catalyst to obtain a prepolymer; and a second step of further adding the persulfate-based catalyst to the prepolymer obtained in the first step and the residual monomer, followed by the polymerization and termination of the polymerization.

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: An aqueous dispersion of a copolymer with copolymerized units a) of at least one ethylenically unsaturated carboxylic acid, b) of at least one nonionic ethylenically unsaturated surfactant monomer, c) of at least one C1-C2-alkyl methacrylate, d) of at least one C2-C4-alkyl acrylate, where the alkyl chain length averaged over the number of alkyl groups of the alkyl acrylate is 2.1 to 4.0, is described. Following neutralization with alkali, the dispersion serves as associative thickener, in particular for liquid detergent and cleaner formulations. The thickeners are characterized by high transparency and high thickening effect coupled with high shear dilution.

Abstract: Durable superhydrophobic coating composition having a composition ranging from about 10 to about 80 w.t. % of an acrylic polymer resin, from about 5 to about 40 w.t. % of a polysiloxane oil, from about 1 to about 50 w.t. % of hydrophobic particles, from about 0.1 to about 10 w.t. % metal oxides, and the remainder being one or more solvents and optionally other additives. Methods of making the coating, as well as coated substrates, are also provided.

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 invention relates to a process for preparing maleic acid-isoprenol copolymers from a) 30% to 80% by weight of maleic acid, b) 5% to 60% by weight of isoprenol, c) 0% to 30% by weight of one or more further ethylenically unsaturated monomers, which comprises polymerizing maleic acid, isoprenol and optionally the further ethylenically unsaturated monomer in the presence of a redox initiator and of a chain transfer agent at a temperature in the range from 10 to 80° C.

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

Abstract: The present invention relates to a polymer composition, comprising (i) a polypropylene homopolymer, (ii) a polypropylene random copolymer, prepared by copolymerization of propylene with an olefin comonomer and having an amount of olefin comonomer units of 0.2 to 5 wt %, and (iii) an elastomeric copolymer of propylene and at least one olefin comonomer, the polymer composition having a tensile modulus, determined according to ISO 527-2/1B at 1 mm/min. and 23° C., of at least 1200 MPa.

Abstract: The invention pertains to a process wherein initiators having a half-life from 0.0001 hour to 0.05 hour at the polymerization temperature are dosed to a polymerization mixture. The dosing of such initiator allows improved control of the polymerization rate and faster polymerization rates, and the process will render a polymer with very low residual initiator levels.

Abstract: A polymer composition comprising A) a first polymer comprising (a) hydrophobized nanoparticle; (b) C1 to C18, straight, branched, or cyclic alkyl(meth)acrylate; (c) N-methylol(meth)acrylamide or a monomer of formula (I) R—(OCH2CH2)a—O—C(O)—C(R1)?CH2??(I) ?wherein R is hydrogen, C1-C4 alkyl, or —C(O)—C(R1)?CH2, and R1 is H or —CH3; said first polymer in contact with B) a second polymer comprising (d) a fluorinated monomer of formula (II) Rf1-L-X—C(O)—C(R)?CH2??(II) ?wherein Rf1 is a monovalent, partially or fully fluorinated, linear or branched, alkyl radical having 2 to about 100 carbon atoms; optionally interrupted by 1 to about 50 oxygen atoms; wherein the ratio of carbon atoms to oxygen atoms is at least 2:1 and no oxygen atoms are bonded to each other; L is a bond or a linear or branched divalent linking group having 1 to about 20 carbon atoms, said linking group optionally interrupted by 1 to about 4 hetero-radicals selected from the group consisting of —O—, —NR6—, —S—, —SO—, —SO2—, and —N(R6)

Abstract: A propylene-based polymer comprising the following component (A) insoluble in p-xylene at 25° C. and component (B) soluble in p-xylene at 25° C., wherein (i) the weight average molecular weight (Mw) measured with GPC is 100,000 to 1,000,000, (ii) the content of the component insoluble in hot p-xylene is 0.3% by weight or lower, and (iii) the degree of strain hardening (? max) in measurement of elongational viscosity is 2.0 or higher; and a method for producing the same, along with a resin composition comprising a propylene-ethylene copolymer (Z) in an amount of 50.0 to 99.9% by weight and a propylene-based polymer (M) in an amount of 0.1 to 50.0% by weight. Component (A): a component (CXIS) insoluble in p-xylene at 25° C., having requirements specified by (A1) to (A5). Component (B): a component (CXS) is soluble in p-xylene at 25° C., having requirements specified by (B1) to (B4).

Abstract: The invention pertains to a process to polymerize one or more monomers wherein at most 90% w/w of a safely useable amount of a first initiator is used and a second initiator is dosed at least after the start of the polymerization, in an amount such that essentially the full cooling capacity of the polymerization reactor is used, resulting in a cost efficient process to make polymers, particularly polymers comprising polymerized vinyl chloride.

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: A method is described for producing an aqueous thickener dispersion from a monomer composition made of at least one ethylenically unsaturated carboxylic acid and at least one ethylenically unsaturated hydrophobic monomer, (i) an at least partially polymerized pre-emulsion being produced from 10 to 80 wt.-% of said monomer composition, and (ii) the residual quantity of said monomer composition being added completely to the at least partially polymerized pre-emulsion and initiating a radical polymerization. The monomer composition preferably also comprises an associative monomer. The method avoids disadvantages of batch polymerization, such as inadequate batch-to-batch reproducibility and safety problems.

Abstract: Disclosed is a method of producing a polyolefin composition comprising contacting a metallocene pre-catalyst, co-catalyst, and a stoichiometric excess of a metal alkyl; adding a first olefin monomer; and polymerizing the first monomer for a time sufficient to form the polyolefin. The method allows for the use of minimum amounts of activating co-catalyst and metallocene pre-catalyst. Also disclosed is a method of producing a block polyolefin composition comprising contacting a metallocene pre-catalyst, a co-catalyst, and a stoichiometric excess of a metal alkyl; adding a first olefin monomer; polymerizing the first monomer for a time sufficient to form the polyolefin; adding a second monomer; and polymerizing the second olefin monomer for a time sufficient to form said block polyolefin composition. Also disclosed are amorphous atactic polymer and copolymer compositions made according to the present invention.

Abstract: Solving problems in the prior art, provided are a resist polymer which is small in lot-to-lot, reactor-to-reactor and scale-to-scale variations, and contains no high polymer, is excellent in solubility and storage stability, and is suitable for fine pattern formation, and a method for production thereof. The present invention provides the resist polymer at least having a repeating unit having a structure which is decomposed by an acid to become soluble in an alkali developer and a repeating unit having a polar group to enhance adhesion to a substrate, characterized in that a peak area of a high molecular weight component (high polymer) with molecular weight of 100,000 or more is 0.1% or less based on an entire peak area in a molecular weight distribution determined, by gel permeation chromatography (GPC).

Abstract: Provided herein are methods for the preparation of telechelic polyolefins via polymerization reaction with a terpene initiator.

Abstract: The invention provides a process for polymerizing a polymer comprising monomeric units derived from styrene and 1,3-butadiene, said process comprising: A) adding less than 60 weight percent of the total amount of the butadiene used in the polymerization, to a reactor comprising the total amount of styrene used in the polymerization and solvent; B) adding at least one initiator to the reactor, and allowing the reaction to proceed for a time t; C) adding the remaining amount of butadiene to the reactor in two or more separate additions; and wherein for each butadiene addition, the amount of subsequent butadiene added is less than, or equal to, the amount of butadiene added in the immediately prior addition; and wherein for each butadiene addition, the butadiene is added over a time, tnc, and after each addition, the reaction is allowed to proceed for a time, tnr, wherein n is the number of the butadiene addition, and for each addition, n is independently greater than, or equal to, 1.

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: A polyethylene may be prepared using a mixture of a silica supported catalyst and a magnesium chloride supported catalyst. By changing the ratio of the two catalysts, the polyethylene produced may have a varying bulk density and shear response. The method allows for the tuning or targeting of properties to fit a specific application, such as a blow molding or vapor barrier film.

Abstract: The invention provides a process for polymerizing a polymer comprising monomeric units derived from styrene and 1,3-butadiene, said process comprising: A) adding less than 60 weight percent of the total amount of the butadiene used in the polymerization, to a reactor comprising the total amount of styrene used in the polymerization and solvent; B) initiator to the reactor, and allowing the reaction to proceed for a time t; C) adding the remaining amount of butadiene to the reactor in two or more separate additions; and wherein for each burtadiene addition, the amount of subsequent butadiene added is less than, or equal to, the amount of butadiene added in the immediately prior addition; and wherein for each butadiene addition, the butadiene is added over a time, tnc, and after each addition, the reaction is allowed to proceed for a time, tnr, wherein n is the number of the butadiene addition, and for each addition, n is independently greater than, or equal to, 1.

Abstract: The invention relates to copolymers comprising three segments of different ion density, the fraction of the ionic monomers in each segment being from 1 to 100 mol %, the second and third segment containing ethylenically unsaturated monomers of the respectively preceding segment, and the copolymers being preparable by means of a monofunctional initiator by way of NMP or RAFT. The invention further relates to a process for preparing copolymers and to their use as dispersants.

Abstract: There is provided a vinylpyrrolidone-based copolymer having as essential components N-vinylpyrrolidone and hydroxyl group-containing (meth)acrylate, which gives a favorable crosslinked coating film, and a method for production by which the copolymer is easily obtained. A vinylpyrrolidone-based copolymer of the present invention contains a constitutional unit derived from N-vinylpyrrolidone and a constitutional unit derived from hydroxyl group-containing (meth)acrylate at a specific ratio, in which a K value according to Fikentscher is 12 or more, water insoluble matter is 0.5% by mass (on the basis of solid content) or less, and each content of iron, nickel, chromium, sodium and calcium is 500 ppb (on the basis of mass: the same hereinafter) or less, or electrical conductivity of a 10% by mass-aqueous solution of the vinylpyrrolidone-based copolymer is 35 ?S/cm or less.

Abstract: The invention pertains to a process to polymerize one or more monomers wherein one or more initiators and optionally one or more surfactants are added to a polymerization mixture when the pressure in the polymerization reactor is dropping. This process allows a shorter polymerization time due to a higher pressure drop rate at the end of the polymerization reaction. Moreover, the cooling capacity of the polymerization reactor is used more efficiently.

Abstract: Provided is a process for producing a fluoropolymer containing repeating units based on a fluoromonomer represented by the following formula (m) in an amount of from 5 to 50 mol % based on the entire repeating units in the polymer by polymerization reaction of tetrafluoroethylene and the fluoromonomer, wherein the polymerization reaction is carried out by continuously charging the reactor with tetrafluoroethylene and the fluoromonomer: wherein ml is an integer of from 1 to 6. Also provided is an electrolyte material for an electrolyte fuel cell which can be operated at a high temperature to obtain a high output, wherein the electrolyte material contains the fluoropolymer produced by the process.

Abstract: A method of preparing a polymer having a tapered block copolymer structure. The method comprises polymerizing a first olefin monomer and a different second olefin monomer in the presence of a catalyst supporting living or quasi-living polymerization. In certain embodiments, the catalyst comprises two neutral metal complexes. In preferred embodiments, a tapered block copolymer structure is formed by adding one monomer in a single batch at the start of the polymerization reaction, and adding a second monomer throughout the course of the reaction. The present invention also provides polymers having one or more tapered block copolymer sections, and compositions based on these polymers.

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: The present invention provides method for recovering fossil-based materials from oil sources using multifunctional, multipolymeric continuous composition spectrum surfactant mixtures. The invention also provides methods for reducing the loss of volatile organic compounds (VOCs) from oil storage containers using multifunctional, multipolymer surfactants. The multifunctional, multipolymer surfactants are characterized by a hydrophobic part and a hydrophilic part. The hydrophobic part of the polymer surfactants includes functionalities that impart a polarity of greater than 0 Debye to the hydrophobic part. The polymer surfactants are further characterized by molecular weights that are above their entanglement weights. The result is polymer surfactants and their continuous composition surfactant-thickener mixtures with demulsifying characteristics.

Abstract: Methods of producing vinyllactam copolymers which include: providing at least one water-soluble N-vinyllactam; providing at least one hydrophobic comonomer; and subjecting the at least one water-soluble N-vinyllactam and the at least one hydrophobic comonomer to free-radical polymerization in an organic solvent in the presence of an initiator, under a combination of process measures selected from the group consisting of A and B; wherein: (A) comprises (i) polymerization under reflux, and at least two of (ii), (iii), (iv), (v), (vi), and (vii), wherein (ii) comprises an addition of at least 5 mol % of N-vinyllactam to the polymerization mixture if at least 70 mol % of the total amount of hydrophobic monomer used have completely reacted, (iii) comprises return of condensate formed in the reflux from below to the polymerization mixture, (iv) comprises introduction of the initiator in the form of a solution in an organic solvent from below into the polymerization mixture, (v) comprises addition of N-vinyllacta

Abstract: Disclosed is a method of producing a polyolefin composition comprising contacting a metallocene pre-catalyst with a substoichiometric amount of a co-catalyst; adding a first olefin monomer; and polymerizing the first monomer for a time sufficient to form the polyolefin. The method allows for the use of a minimum amount of activating co-catalyst, and allows for the production of stereoregular and non-stereoregular polyolefins. The use of configurationally stable metallocene pre-catalysts allows for the production of monomodal isotactic polyolefins having narrow polydispersity. The use of configurationally unstable metallocene pre-catalysts allows for the production of monomodal atactic polyolefins having narrow polydispersity. The method of the present invention optionally further comprises contacting the polyolefin with a second amount of said co-catalyst; adding a second olefin monomer; polymerizing said second olefin monomer to form a block-polyolefin composition.

Abstract: Disclosed is a polyethylene composition. The composition comprises single-site multimodal resin A and single-site multimodal resin B, wherein resin A differs from resin B in molecular weight, in monomeric composition, in density, in long chain branch concentration or distribution, or in combinations thereof. Disclosed is also a method for making the polyethylene composition. The method comprises polymerizing, in the presence of two or more single-site catalysts, ethylene or its mixture with a C3-C10 ?-olefin to form a first multimodal resin and continuing the polymerization in the presence of the same catalysts but in a different hydrogen concentration, in a different monomer composition, or at a different temperature to form a second multimodal resin.

Abstract: Processes for preparing graft polymers and their use for inhibiting gas hydrates

Abstract: There is provided a process for producing a polymer comprising the steps of (a) adding at least one low-reactivity monomer to a reaction vessel with a decreasing rate of addition, (b) adding at least one high-reactivity monomer to said reaction vessel, (i) wherein less than 1% of all of said high-reactivity monomers, by weight of high reactivity monomers, based on the weight of all said high-reactivity monomers, is added to said reaction vessel before the beginning of said step (a), and (ii) wherein at least half of all of said high-reactivity-monomers, by weight of high reactivity monomers, based on the weight of all of said high-reactivity monomers, is added to said reaction vessel before the completion of said step (a), and (c) adding at least one chain regulator to said reaction vessel prior to the completion of said step (a), wherein said steps (a), (b), and (c) are performed while conditions in said reaction vessel will cause polymerization of said low-reactivity monomer and said high-reactivity

Abstract: A process for making high specific viscosity copolymers of maleic anhydride and an alkyl vinyl either having as specific viscosity of at least 7, preferably 10-50, are made by copolymerizing maleic anhydride and an alkly vinyl ether monomers in the presence of added acetylene.

Abstract: It is to provide a process for producing a polymer for an electrolyte material to prepare polymer electrolyte fuel cells which can be operated at a high temperature and with which high output can be obtained, with a stable composition. A process for producing a fluoropolymer by polymerization reaction of tetrafluoroethylene and a fluoromonomer represented by the following formula (m), wherein the polymerization reaction is carried out by continuously charging the reactor with tetrafluoroethylene and the fluoromonomer: wherein m1 is an integer of from 1 to 6.

Abstract: A process for preparing a water-soluble carboxyl group-containing polymer comprising reacting an ?,?-unsaturated carboxylic acid with a compound having at least two ethylenically unsaturated groups in an inert solvent in the presence of a radical polymerization initiator, the process for preparing a water-soluble carboxyl group-containing polymer being characterized in that the ?,?-unsaturated carboxylic acid is further added to a reaction mixture in which 20 to 70% by mol of an unreacted ?,?-unsaturated carboxylic acid remains, and the ?,?-unsaturated carboxylic acid is reacted with the compound having at least two ethylenically unsaturated groups; and a water-soluble carboxyl group-containing polymer obtainable by the above-mentioned process, wherein the reducing ratio of viscosity of a 0.2% by weight neutralized viscous liquid is less than 25%, and the equilibrium viscosity of the neutralized viscous liquid is 20000 to 50000 mPa·s.

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: It is possible to provide the heat resistant material and coating material for OA equipment which comprise a fluorine-containing multi-segment polymer having heat resistance, abrasion resistance, non-sticking property against toner and oil resistance in addition to flexibility and are used particularly on surfaces of fuser roll and belt. Those materials comprise a fluorine-containing multi-segment polymer having an elastomeric fluorine-containing polymer chain segment A and a non-elastomeric fluorine-containing polymer chain segment B, and the elastomeric fluorine-containing polymer chain segment A comprises not less than 90% by mole of perhaloolefin unit as a recurring unit and imparts flexibility to the whole polymer.