Abstract: This invention relates to a process for controlling the architecture of copolymers of at least two unsaturated monomers, made by free-radical polymerization in the presence of a cobalt-containing chain transfer agent, including the control of molecular weight, degree of branching and vinyl end group termination, by varying at least one of the variables of molar ratio of monomers, their relative chain transfer constants, polymerization temperature and degree of conversion and amount of cobalt chain transfer agent; and polymers made thereby.

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: In a process for preparing ethylene-vinyl acetate copolymers in which a mixture of ethylene and vinyl acetate is polymerized continuously in the presence of free-radical polymerization initiators and, if desired, molecular weight regulators in a cooled tube reactor at a pressure in the range from 1000 to 3500 bar, and the poly-merization initiator is added at the beginning and at two or more points along the tube reactor, and temperature changes in the reaction mixture along the tube reactor, between the first temperature maximum and the last addition of the polymerization initiator, are within a range of not more than 20° C.

Abstract: Enhanced conversion rates are realized in a suspension polymerization process for styrene through the use of peroxide initiators having one hour half life temperatures from 101° to 111° C. are disclosed. Also disclosed are suitable initiator combinations which provide polymeric products with low residual monomer content at reduced process temperatures, polymerizable compositions containing such initiators and products produced by such processes and compositions.

Abstract: A hydrogenated product of a ring-opening metathesis polymer comprising structural units as shown below has improved heat resistance, pyrolysis resistance and light transmission and is suited as a photoresist for semiconductor microfabrication using UV or deep-UV. A resist composition comprising the polymer as a base resin is sensitive to high-energy radiation and has excellent sensitivity, resolution, and etching resistance.

Abstract: A method for preparing an intrinsically conductive copolymer comprising preparing an emulsion latex in a medium; forming a mixture which comprises at least one cyclic heteroatom containing monomer, the emulsion latex in the medium and an additive under first condition effective to maintain the emulsion latex in a first stabilized emulsion state, causing the monomer in the mixture to polymerize under second condition effective to produce the conductive copolymer in a second stabilized emulsion state. Additives include cyclodextrins, partially alkylated cyclodextrins, poly(vinyl alcohol), partially hydrolyzed poly(vinyl acetate), poly(vinyl acetate) and mixtures thereof.

Abstract: An olefin polymerization apparatus is disclosed wherein monomer, diluent and catalyst are circulated in a continuous pipe loop reactor and an intermediate product slurry is recovered by a continuous product take off means. The intermediate product slurry is passed to a hydrocyclone to stratify polymer particles based on size. A slurry containing predominantly fines is withdrawn overhead and returned to the reaction zone. The slurry containing predominantly fines is preferably returned to the polymerization zone just upstream of the circulation pump and in a preferred embodiment this pressure differential is the sole driving force for the hydrocyclone separation. In another embodiment the product slurry from the bottom of the hydrocyclone is passed to a solids-liquid separator where the solids settle to the bottom and essentially polymer free diluent is recycled. In another embodiment, the intermediate product slurry is withdrawn via a conical settling leg.

Abstract: A beaded polymeric adsorbent has a core part; a shell part arranged around the core part, with one of the parts having a lipophilic property and another of the parts having a hydrophilic property, and is produced by preparing an organic phase composed of water insoluble monounsaturated and poly unsaturated comonomers; preparing an aqueous phase composed of a mixture of water soluble monounsaturated and polyunsaturated comonomers; forming a dispersion of the organic phase and the aqueous phase in a single vessel; and creating conditions for first polymerizing of one of the phases which forms the core part and thereafter polymerizing the other of the phases which forms the shell part.

Abstract: The present invention relates to a hydroxy-functional copolymer P, which is present as a dispersion and/or solution in water, and is obtained by successively carrying out process steps A-D: A) initially introducing a hydrophobic polymer containing hydroxyl groups into a reaction vessel, B) introducing an initiator component into that vessel, C) subsequently polymerizing a hydrophobic monomer mixture containing hydroxyl groups in that vessel and D) subsequently polymerizing a hydrophilic monomer mixture containing hydroxyl and acid groups in that vessel. The present invention also relates to a process for the preparation of copolymers P following the procedure previously set forth and to coating compositions containing these copolymers P and one or more crosslinking agents.

Abstract: 1.

Abstract: Certain mixtures of two superabsorbent powders having very different capillary suctions exhibit a resulting capillary suction which approaches the higher value. The resulting mixtures simultaneously exhibit a high capillary suction and a high intrinsic absorption capacity.

Abstract: A novel method for making improved cement fluid loss additives comprising copolymers of acrylamide having desirable viscosity and fluid loss control properties. The method combines (1) the use of oxygenated make-up water to dissolve acrylamide monomers, derivatives or mixtures thereof to form a reaction mixture for polymerization of the monomers with (2) a second “condition” or set of conditions. The second “condition” or set of conditions is either (a) using of two heating stages to induce polymerization, or (b) adding a small amount of acrylic acid to the reaction mixture before exposing the reaction mixture to a temperature sufficient to polymerize the monomers. The two heating stages of (a) involve (i) an initial, lower temperature stage followed by (ii) a higher temperature stage.

Abstract: A process for the polymerisation of olefins in the gas phase is carried out in the presence of a supported transition metal catalyst. The process involves a prepolymerisation step which may be performed in-situ and in particular the prepolymer may be prepared in the dry phase. The catalyst may for example comprise a constrained geometry transition metal complex supported on silica and used in the presence of an activator. The prepolymerisation step enables the activity of the catalyst to be improved.

Abstract: Modified polypropylenes of improved processability are produced by a continuous method by absorptively charging polypropylene particles at 20° to 120° C. with a gas mixture, which contains oxygen and bifunctional, unsaturated monomers, and melting the mixture. The modified polypropylenes of improved processability as well as mixtures with unmodified polypropylenes are suitable for the production of films, sheets, fibers, panels, coatings, pipes, hollow objects and foamed materials.

Abstract: The present invention relates to a hydroxy-functional copolymer P, which is present as a dispersion and/or solution in water, and is obtained by successively carrying out process steps A-D: A) initially introducing a hydrophobic polymer containing hydroxyl groups into a reaction vessel, B) introducing an initiator component into that vessel, C) subsequently polymerizing a hydrophobic monomer mixture containing hydroxyl groups in that vessel and D) subsequently polymerizing a hydrophilic monomer mixture containing hydroxyl and acid groups in that vessel. The present invention also relates to a process for the preparation of copolymers P following the procedure previously set forth and to coating compositions containing these copolymers P and one or more crosslinking agents.

Abstract: A process for production of diene rubber polymers wherein, during production of a diene rubber polymer by emulsion polymerization, the polymerization is initiated using a portion of the starting material and the polymerization is continued with either continuous or intermittent dropwise addition of the remainder of the starting material during the polymerization, and wherein at least ½ of the total amount of the water and of the monomer in the starting material used is added dropwise during the polymerization, and the temperature of the dropwise added water and monomer is kept to at least 20° C. below the polymerization temperature. The process can produce industrially useful diene rubber polymer latexes at a high productivity rate.

Abstract: In a process for the high-pressure polymerization of ethylene in a high-pressure autoclave or in a high-pressure tube reactor having one or more metering points for one or more peroxides, no peroxide or a reduced amount of peroxide is metered in during the time interval in which the pressure is lowered by opening a pressure maintenance valve and the original amount of peroxide per unit time is metered in again as soon as the pressure after closure of the pressure maintenance valve has built up again so that it exceeds 90% of the pressure difference between nominal pressure and lowered pressure.

Abstract: Fine powders of modified PTFE having a “core-shell” structure; the fine powder being formed by:

Abstract: A process for producing polyolefins having a bimodal molecular weight distribution, the process comprising producing a first polyolefin fraction in the presence of a catalyst in a first loop reactor, and producing a second polyolefin fraction in the presence of the catalyst in a second loop reactor which is serially connected to and downstream of the first loop reactor, the first and second polyolefin fractions being blended in the second loop reactor to form a polyolefin having a bimodal molecular weight distribution, at least the first loop reactor containing a diluent under supercritical conditions which is circulated around the loop of the reactor, and wherein at least the first loop reactor is provided with a fluff concentrating device communicating with the loop and in which polyolefin fluff of the first fraction is concentrated in the supercritical diluent, and polyolefin fluff of the first polyolefin fraction is transferred together with an amount of supercritical diluent from the fluff concentrating

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: This invention discloses a process for synthesizing random styrene-isoprene rubber comprising: (1) continuously charging isoprene, styrene, an initiator, and a solvent into a first polymerization zone, (2) allowing the isoprene and styrene to copolymerize in the first polymerization zone to total conversion of 60 to 95 percent to produce a polymer cement containing living styrene-isoprene chains, (3) continuously charging the polymer cement containing living styrene-isoprene chains and additional isoprene monomer into a second polymerization zone, wherein from 5 to 40 percent of the total amount of isoprene changed is charged into the second polymerization zone, (4) allowing the copolymerization to continue in the second polymerization zone to a conversion of the isoprene monomer of at least 90 percent wherein the total conversion of styrene and isoprene in the second polymerization zone is limited to a maximum of 98 percent, (5) withdrawing a polymer cement of random styrene-isoprene rubber having living cha

Abstract: The present invention can provide a water-absorbent or water-retention material comprising water-absorbent resin derived from monomer unit components comprising 40 to 99 wt. % of hydroxyl alkyl (meth)acrylate, 1 to 60 wt. % of (meth)acrylic acid and/or alkali metal salt thereof and 0.00001 to 3 wt. % of crosslinking agent; and a water-absorbent or water-retention material comprising water-swellable polymer which is obtained by further thermally crosslinking a particles of partially alkaline neutralized product of a copolymer of 20 to 99 mol % of acrylamide and 1 to 80 mol % of acrylic acid. The water-absorbent or water-retention material of the present invention is not readily subject to an influence of salts, and the absorbency does not deteriorate with respect to an aqueous solution containing a great amount of metallic ion of salts.

Abstract: A process is described for copolymerizing ethylene with vinyl esters and, if desired, with further vinylic comonomers in a tube reactor at pressures of from 500 to 4000 bar and at not more than 220° C., which comprises initiating the free-radical polymerization at at least two locations of the tube reactor by adding a catalyst/initiator and adjusting the temperature profile within the reactor such that the temperature maxima downstream of the initiation locations are from 150 to 220° C. and differ by less than ±10° C. from one another.

Abstract: A process for producing high density polyethylene in the presence of a metallocene catalyst system in two liquid full loop reactors in series, wherein in a first reactor a first polyethylene product is polymerized substantially by homopolymerization of ethylene and hydrogen, and in a second reactor serially connected to the first reactor downstream thereof a second polyethylene product is copolymerized from ethylene and an alpha-olefinic comonomer comprising from 3 to 8 carbon atoms, and a hydrogenation catalyst is introduced into the reactants downstream of the first reactor, the hydrogenation catalyst comprising a second metallocene catalyst of general formula: Cp2MXn where Cp is a substituted or unsubstituted cyclopentene dienyl group; M is a transition metal from Group IVB of the Periodic Table or vanadium; X is a halogen or a hydrocarbyl group having from 1 to 10 carbon atoms; and n is the valency of the metal M minus 2.

Abstract: A process for producing a substantially dry polymer particle powder. A mixture of polymerization reagents is formed from a mixture of at least one monomer source and a solvent selected from the group consisting essentially of water and organic solvents and an initiator source. The mixture of polymerization reagents is sprayed into a heated, controlled atmosphere, forming droplets of the mixture which are allowed to fall through the heated, controlled atmosphere for a sufficient period of time to obtain a desired degree of polymerization. The solvent is continuously evacuated from the atmosphere during the polymerization process.

Abstract: Injection molded plastic parts (such as containers for ice cream or margarine, lids for the containers and crates) are made from a polyethylene resin having a controlled but narrow molecular weight distribution and a uniform comonomer distribution. The combination of narrow molecular weight distribution and uniform comonomer distribution allows the parts to be more easily molded whilst still maintaining a surprisingly high level of physical properties in the finished parts. The polyethylene resin is prepared in a dual reactor polymerization process.

Abstract: Process for the preparation of polyvinylarene polymer particles by suspension polymerization, wherein (a) vinylarene monomers are suspended in an aqueous medium to yield a suspension; (b) the temperature of the suspension is adjusted to a temperature above 50° C., at which temperature an initiator is added; (c) subsequently, the reaction temperature is increased by 5 to 30° C. per hour until a temperature of at least 120° C. has been reached; and (d) the temperature is retained at a temperature of at least 120° C. until the polymerization is complete.

Abstract: In gas phase fluid bed polymerization processes, operation can be achieved over wider ranges of fluidizing gas velocities without incurring undue energy costs by adjusting the pressure drop through the grid below the bed to provide a ratio of pressure drop through the grid to pressure drop through the grid and bed above about 0.15:1. The range of fluidizing gas velocities can enhance the practicality of operating the processes over varying bed heights while reducing the risk of forming deposits of polymer. The processes of the invention are particularly useful to accommodate start-ups, catalyst transitions and shutdowns.

Abstract: A process for producing polyethylene having improved crack resistance, the process comprising copolymerizing ethylene and an alpha-olefinic comonomer comprising from 3 to 8 carbon atoms, in the presence of a chromium-based catalyst in a first reactor, feeding the polyethylene copolymer thereby produced and the chromium-based catalyst to a second reactor, and in the second reactor copolymerizing ethylene and an alpha-olefinic comonomer comprising from 3 to 8 carbon atoms, in the presence of the chromium-based catalyst thereby to produce a second polyethylene product, the first and second polyethylene products forming a combined polyethylene having a monomodal molecular weight distribution.

Abstract: A process for producing polyethylene in a two step polymerisation process that comprises the steps of: (a) homopolymerising ethylene in the presence of a first catalyst comprising an activated chromium catalyst in a first reactor to produce a first polyethylene fraction; (b) transferring the first polyethylene fraction produced in the first reactor and at least a portion of the first catalyst to a second reactor; (c) in the second reactor homopolymerising ethylene or copolymerising ethylene and an alpha-olefinic comonomer having from 3 to 10 carbon atoms in the presence of a second catalyst under conditions which suppress residual activity in the first catalyst to produce a second polyethylene fraction; and (d) retrieving from the second reactor polyethylene comprising a blend of the first and second polyethylene fractions.

Abstract: A continuous emulsion polymerization process consisting of multiple stirred-tanks in series is used to produce a broad particle-size distribution for vinyl acetate-based emulsions utilizing polyvinyl alcohol as a protective colloid. When low-molecular-weight grades of PVOH and a continuous process are employed, a high-solids emulsion can be produced. This process eliminates the need for a co-surfactant, which is required to make similar high-solids emulsions via a batch process.

Abstract: Particles of a copolymer of a vinyl arene and a copolymerizable compound containing a polar moiety and a vinyl moiety containing water may be prepared by forming a mixture of monomers and small amounts of water and polymerizing under agitation to 20 to 70% conversion and then suspending the mass in water and finishing the polymerization. The resulting polymer beads contain finely dispersed water which is useful as an environmentally acceptable blowing agent.

Abstract: A process for producing high density polyethylene in the presence of a Ziegler-Natta catalyst system in two liquid full loop reactors in series, wherein in a first reactor a first polyethylene product is polymerized substantially by homopolymerization of ethylene and hydrogen, optionally with a minor degree of copolymerization of ethylene with an alpha-olefinic comonomer comprising from 3 to 8 carbon atoms, and in a second reactor serially connected to the first reactor downstream thereof a second polyethylene product is copolymerized from ethylene and an alpha-olefinic comonomer comprising from 3 to 8 carbon atoms, and a hydrogenation catalyst is introduced into the reactants downstream of the first reactor.

Abstract: The invention relates to a process for the preparation of a creep-resistant polypropylene by means of the following steps: (a) copolymerizing propylene and ethylene into a random copolymer at 40 to 110° C. using: a catalyst system of the above-mentioned type; a portion of ethylene or C4-C10-&agr;-olefin leading to 1.0 to 10.0% by weight of ethylene repeating units in said random copolymer; and no or a minimal amount of hydrogen leading to a MFR10 value of between 0.01 and 5.0 g/10 min for said random copolymer, if this step is performed first, or to a MFR2 value for said polypropylene of between 0.05 and 0.40 g/10 min, if this step is performed after step (b); the proportion of random copolymer of this step being from 20 to 80% by weight of said polypropylene, (b) polymerizing propylene at 40 to 110° C. using: a catalyst system of the above-mentioned type; no or a minimal portion of ethylene leading to 0.0 to 1.

Abstract: A system for pressurizing a propylene polymerization reactor includes: a pressurization vessel including an internal heat exchanger; a pressure sensor for monitoring the pressure in the vessel, the pressure sensor providing a signal indicative of the pressure in the vessel; a control valve for supplying heated gas to a first region of the vessel in response to signals from the pressure sensor, the first region of the vessel being maintained above the critical temperature and pressure of propylene; a temperature sensor for monitoring the temperature in a second region of the pressurization vessel, the temperature sensor providing a signal indicative of the temperature in the second region of the vessel; and a control valve for supplying a cooling medium to the internal heat exchanger to cool propylene in the second region below the critical temperature of propylene at the pressure in the pressurization vessel.

Abstract: The invention concerns a process for producing polymethacrylate moulding compounds, which have high thermal dimensional stability and high stability with respect to thermal decomposition, by the radical polymerization of methylmethacrylate monomers and optionally comonomers in at least two reactors operated successively, ensuring a high degree of blending. The process is characterized in that: a) a first reactor is operated at a temperature of less than 120° C.; and b) a second reactor or further successive reactors is/are operated in a temperature range of more than 130° C. and at most 200° C.

Abstract: Modified polypropylenes of improved processability are produced by a continuous method by absorptively charging polypropylene particles at 20° to 120° C. with a gas mixture, which contains oxygen and bifunctional, unsaturated monomers, and melting the mixture. The modified polypropylenes of improved processability as well as mixtures with unmodified polypropylenes are suitable for the production of films, sheets, fibers, panels, coatings, pipes, hollow objects and foamed materials.

Abstract: Disclosed is a process for preparing copolymers which comprises, in the order stated: (1) adding monomers containing unsaturated carbon-to-carbon bonds, a first polymerization initiator, a second polymerization initiator, and a solvent to a reaction vessel; (2) purging the resulting solution with an inert gas; (3) sealing the reaction vessel and pressurizing it by addition of an inert gas to a pressure of from about 20 to about 600 kilopascals over ambient atmospheric pressure; (4) maintaining the temperature within the pressurized reaction vessel at a temperature of from about 50 to about 100.degree. C. for a period of from about 60 to about 300 minutes; (5) thereafter maintaining the temperature within the pressurized reaction vessel at a temperature of from about 80 to about 115.degree. C.

Abstract: The present invention generally relates to the use of certain ruthenium and osmium complexes that are substantially inactive at a first temperature (preferably about room temperature) but become progressively more active at a higher second temperature. This difference in reactivities allows the reaction mixture to be formed and manipulated at the first temperature until polymerization is desired. When appropriate, the reaction mixture is heated to a suitable temperature (preferably greater than 50.degree. C.) to activate the catalyst and to initiate polymerization. Because both the initiation and the rate of polymerization may be controlled with temperature, the inventive methods are especially suitable for ring opening metathesis polymerization ("ROMP") reactions and for molding polymer articles that require extended pot-lives.

Abstract: An improved process for making allylic/ethylenic copolymers is disclosed. Increasing the reaction temperature during addition of the ethylenic monomer/initiator mixture results in a substantial increase in the polymer yield obtained compared with the yield from a conventional process in which a constant temperature is used. Copolymers made by the process include valuable coating resins such as styrene-allyl alcohol and hydroxy-functional acrylic copolymers.

Abstract: Monovinyl aromatic polymer compositions with high melt strength, good flow and good heat properties which are suitable for fast injection molding, blow molding and thermoforming applications, comprising non-linear monovinyl aromatic polymers and copolymers having comb-type structures with 3 branches, star type structures with 4 to 6 branches, and/or dendritic structures in which the branches themselves have attached branched units. These compositions possess inherent melt strength and can be blow molded or thermoformed without sagging or molded into articles in shorter cycle times using less material than linear monovinyl aromatic polymers and copolymers with the same flow and heat distortion temperatures.

Abstract: The present invention provides a Ziegler-Natta catalyst based on titanium and vanadium useful in solution processes for the polymerization of olefins having a low amount of aluminum and magnesium. The catalysts of the present invention have a molar ratio of magnesium to the first aluminum component from 4.0:1 to 8.0:1 and molar ratio of magnesium to titanium and vanadium from 4.0:1 to 8.0:1. The invention provides a novel catalyst preparation method to substantially increase the polymer molecular weight in the high temperature ethylene polymerization process.

Abstract: Disclosed is an aromatic polycarbonate-styrene polymer resin composition comprising (A) an aromatic polycarbonate, (B) a specific rubber-modified styrene polymer and (C) a compatibility agent which is a copolymer containing an aromatic vinyl monomer and which has a non-uniform distribution with respect to the proportions of component monomers constituting the copolymer, so that the copolymer comprises copolymer molecules having different solubility parameter (SP) values, wherein the difference in SP value between the copolymer molecule having a maximum SP value and the copolymer molecule having a minimum SP value is from 0.4 to 0.6 (cal/cm.sup.3).sup.1/2, and wherein the copolymer has an average SP value of from 10.6 to 11.0 [(cal/cm.sup.3).sup.1/2 ].

Abstract: Process for the preparation of polyethylene by the homopolymerization of ethylene or by the copolymerization of ethylene and of at least one alpha-olefinic comonomer containing from 3 to 10 carbon atoms, in two reactors for loop polymerization in liquid phase which are connected in series in the presence of a chromium catalyst, in which ethylene and the chromium catalyst are first introduced into the first reactor at a temperature of 95 to 110.degree. C. to produce an ethylene homopolymer of low molecular weight of a melt index MI.sub.2 of at least 1 g/10 minutes and in which the ethylene homopolymer thus obtained is next transferred into the second reactor to which ethylene and optionally the alpha-olefinic comonomer is added, at a temperature of 80 to 90.degree. C. to obtain an ethylene copolymer of high molecular weight.

Abstract: Process for manufacturing ethylene copolymers by polymerizing ethylene and a minor amount of C.sub.3 -C.sub.6 alphaolefins in particle form in slurry reactor in the presence of an ethylene polymerizing catalyst. According to the invention the polymerization is carried out in propane diluent by using a metallocene catalyst activated with an alumoxane compound.

Abstract: Low molecular weight, highly reactive polyisobutene having an average molecular weight M.sub.n of from 500 to 20000 Dalton and containing over 80 mol % of terminal double bonds is prepared by the polymerization of isobutene or an isobutene-containing hydrocarbon stream in the liquid phase and with the aid of a boron trifluoride complex catalyst at from -40 to 0.degree. C. and at from 1 to 20 bar, by a process in which the polymerization reaction is carried out in at least two polymerization stages, the added isobutene being polymerized to a partial conversion of up to 95% in the first polymerization stage and the polymerization of the remaining isobutene being continued in one or more subsequent polymerization stages, without or after prior isolation of the polyisobutene formed in the first polymerization stage.

Abstract: The object of the present invention is to provide an polymerization method for carboxylated styrene-butadiene latex using paper coating with the gel content having 50%.about.90% by controlling the reaction with the sole use of tertiary-dodecyl mercaptan in the high temperature polymerization method with following steps comprising;i) reacting and batch charged polymerizing 10.about.20 wt % of total styrene and butadiene monomers with small quantity of acid monomers, emulsifier, initiator and reducing agent at about 60.degree. C. in initial polymerization step; andii) reacting and continuously charged polymerizing 80.about.90 wt % of total styrene and butadiene monomers with small quantity of acid monomers, emulsifier and tertiary dodecyl mercaptan as chain transfer agent with increasing the polymerization temperature step by step from 70.degree. C., 75.degree. C. to 80.degree. C. in increment polymerization step.

Abstract: Disclosed is an aromatic polycarbonate-styrene polymer resin composition comprising (A) an aromatic polycarbonate, (B) a specific rubber-modified styrene polymer and (C) a compatibility agent which is a copolymer containing an aromatic vinyl monomer and which has a non-uniform distribution with respect to the proportions of component monomers constituting the copolymer, so that the copolymer comprises copolymer molecules having different solubility parameter (SP) values, wherein the difference in SP value between the copolymer molecule having a maximum SP value and the copolymer molecule having a minimum SP value is from 0.3 to 1.0 ?(cal/cm.sup.3).sup.1/2 !, and wherein the copolymer has an average SP value of from 10.6 to 11.0 ?(cal/cm.sup.3 ).sup.1/2 !.

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: An aqueous polymer dispersion is prepared by free radical aqueous emulsion polymerization of a mixture of monomers having at least one ethylenically unsaturated group, which comprises at least 30% by weight of monomers having two conjugated ethylenically unsaturated double bonds, by a process in which the polymerization temperature is varied in the course of the free radical aqueous emulsion polymerization.