Abstract: A blend for blown film which exhibits improved MD/TD tear balance. The blend is a bimodal molecular weight ethylene resin containing two fractions of different molecular weight. The weight fraction of a higher molecular weight component of the blend is about 0.35 to 0.75.

Abstract: A process for the polymerization of olefins in the presence of hydrogen comprising contacting the olefin, a cyclopentadienyl compound and a catalyst comprising a transition metal compound at polymerization conditions.

Abstract: An improved process for the polymerization of styrene is provided. The process comprises feeding styrene monomer and a mixture of peroxides, which decompose at progressively higher temperatures, into a prepolymerization vessel maintained at 200.degree.-270.degree. F. About 20-40% of the styrene in this vessel is converted to polymer (depending on temperature and residence time) and then fed to an extruder where the polymer is raised in temperature by passage through a heat exchanger or through the heated throat of the extruder. During this heating, the polymerization is completed in seconds to minutes in an extruder as the peroxides decompose in sequence as the temperature rises. A final devolatilization zone is provided to remove the final traces of monomer. The molten polymer is then passed through a die and stranded or hot die face cut.

Abstract: The subject invention discloses a styrene-isoprene-butadiene rubber which is particularly valuable for use in making truck tire treads, said rubber being comprised of repeat units which are derived from about 5 weight percent to about 20 weight percent styrene, from about 7 weight percent to about 35 weight percent isoprene, and from about 55 weight percent to about 88 weight percent 1,3-butadiene, wherein the repeat units derived from styrene, isoprene and 1,3-butadiene are in essentially random order, wherein from about 25% to about 40% of the repeat units derived from the 1,3-butadiene are of the cis-microstructure, wherein from about 40% to about 60% of the repeat units derived from the 1,3-butadiene are of the trans-microstructure, wherein from about 5% to about 25% of the repeat units derived from the 1,3-butadiene are of the vinyl-microstructure, wherein from about 75% to about 90% of the repeat units derived from the isoprene are of the 1,4-microstructure, wherein from about 10% to about 25% of the re

Abstract: Graft copolymers and processes for the preparation thereof are provided. The copolymers comprise a base polymer having grafted thereto a monomeric 2-alkenyl azlactone. The surface properties of the graft copolymers can be modified by binding thereto nucleophilic reagents comprising further functional groups with desired properties. Further, the amount of azlactone available at the surface of a graft copolymer for binding to such nucleophilic reagents can be controlled by selecting a surface against which the graft copolymer is formed. The graft copolymers exhibit desirable thermoplastic, melt flow, and adhesion properties and are particularly useful for immobilizing proteins. Methods of immunoassay based on the immobilization of proteins are also disclosed. Another utility of the graft copolymers involves the compatibilizing of immiscible polymer blends.

Abstract: A polyethylene composition which has a wide molecular weight distribution and excellent balance among melt elasticity, flow characteristics and mechanical properties, and which is suitable for use in producing large-scaled hollow plastics articles. The composition comprises a higher molecular weight ethylene polymer or copolymer and a lower molecular weight ethylene polymer or copolymer which is specified in view of the content of o-dichlorobenzene and the ratio of the area under the elution temperature-eluate volume curve between 25.degree.to 90.degree. C. to the area under said curve of 90.degree. C. and above in temperature rising elution fractionation.

Abstract: An impact resistant styrene resin is prepared by the continuous bulk polymerization of a styrene monomer in the presence of a second component having a 5 wt % styrene solution viscosity which may be polybutadiene, styrene-butadiene copolymerization rubber, or mixtures thereof. Preliminary polymerization is carried out in a reactor having a dynamic mixing structure and which is integrated between and connected to the material feed line and the initial-stage polymerization line.

Abstract: Film having good blocking properties and low coefficient of friction is prepared without the presence of antiblock additives from certain thermoplastic ethylene interpolymer products. The thermoplastic ethylene interpolymer products have a density of about 0.935 g/ml or less, a melt flow ratio. I.sub.10 I.sub.2, of at least about 8, and at least about 0.5 percent by weight of the interpolymer product has a weight average molecular weight of at least about 1,000,000 grams/mole. The interpolymer products are a blend or composite of ethylene polymers or copolymers and comprise at least a first interpolymer of ethylene with at least one alpha-olefin monomer. Preferably, the interpolymer products have a melt index, I.sub.2, of from about 0.1 to about 4 grams/10 minutes. The interpolymer products can be made using discrete polymer blends, or preferably, in a multiple reactor sequence. Blown film made from the interpolymer products is especially useful in grocery sack applications.

Abstract: Impact-resistant polystyrene acrylonitrile (ABS) is prepared by free radical polymernation of monomeric styrene and acrylonitrile or equivalents thereof in the presence of preformed, dissolved polbutadiene as a grafting base, the solvents used being in particular ethylbenzene and, at least from time to time, the monomers, and phase inversion taking place when the process has progressed to a certain point, in two or more reaction zones, by a continuous process in which the first reaction zone is present at least in duplicate and is in the form of a stirred kettle in each case, so that one stirred kettle is operated batchwise and alternately with the other in such a way that the reaction mixture is polymerized until phase inversion is complete or the initiator has been consumed, and the particular kettle content is then fed continuously to a second reaction zone in the form of a tube reactor.

Abstract: Polypropylene impact copolymer compositions and visbroken derivatives thereof demonstrate a good balance of low temperature properties and resistance to stress whitening when the homopolymer phase is at least predominantly homopolymeric polypropylene and the rubber phase comprises a major proportion of ethylene with a minor proportion of .alpha.-olefin of at least 4 carbon atoms and a minor proportion of propylene.

Abstract: Disclosed is a process for the production of a rubber-reinforced polymer composition having a bimodal particle size distribution using parallel, substantially plug flow reactors to separately polymerize the same or different solutions of a rubber in a monovinylidene aromatic monomer and optionally at least one other monomer. After separate partial polymerizations, first and second prepolymer compositions are produced containing rubber particles having average particle sizes of from 0.05 to 1.5 micrometer and from 0.7 to 10 micrometer, respectively, with the average rubber particle size of the second prepolymer composition being at least 1.3 times the average rubber particle size of the first prepolymer composition.

Abstract: A process for making a blend of high-density polyethylene polymers containing one or more C3 to C12 .alpha.-olefin comonomers. The process begins in two parallel streams. In one stream ethylene is polymerized alone, and in the second stream ethylene is polymerized with the comonomer(s). The two streams are combined in a subsequent reactor where the polymerization process is completed. The polymerization produces a polymer wherein the comonomer is concentrated in the higher molecular weight fractions.

Abstract: An elastic polyester is continuously prepared by continuously supplying an aromatic polyester and a lactone compound into an extruder which has (A) a cylinder having a shape of 3.ltoreq.L/D.ltoreq.70 (where L represents the length of the cylinder and D represents the inner diameter of the cylinder) and (B) at least one screw and wherein (C) the occupancy ratio of the space in the inner volume of the cylinder in the screw-attached state is not larger than 70%, and reacting the aromatic polyester with the lactone compound while performing melting, delivery and kneading in the extruder, according to this process, the reaction time can be shortened, and an elastic polyester can be easily prepared at a high efficiency by simplified apparatus and operations. The obtained elastic polyester has an excellent durability represented by heat resistance and weatherability and has an excellent rubbery elasticity and mechanical properties.

Abstract: A method for preparing graft polymer dispersions having broad particle size distribution without wildly fluctuating viscosities is disclosed. The method comprises:(a) preparing intermediate graft polyol dispersions containing 30 percent by weight or less solids to achieve a broad distribution of partial sizes in a continuous process and(b) charging the intermediate graft polymer dispersion of (a) to a semi-batch reactor as seeds for further grafting to increase the solids content of the dispersion to above 30 percent by weight. The graft polymer so formed is useful in the production of polyurethanes.

Abstract: A rubber-modified, impactresistant acrylonitrile-butadiene-styrene (ABS) molding material, as obtained by polymerizing styrene and acrylonitrile in the presence of a preformed rubber, dissolved in monomeric styrene and acrylonitrile and, if necessary, a solvent, wherein the rubber is a styrene-butadiene block copolymer and at least one further polymer which is compatible with the styrene-butadiene block rubber or its polystyrene component and is incompatible with polystyrene-acrylonitrile.

Abstract: Polymer blends of at least one ethylene interpolymer product and at least one linear polyethylene are disclosed. The blends have a shear rate at the point of onset of melt fracture at least about 2 percent higher than that obtained for the linear polyethylene alone. The polymer blends are particularly useful for forming films and tapes wherein the melt fracture of the polymer blend is substantially reduced or eliminated, thereby improving extrudability and fabricated article appearance.

Abstract: A process for preparing rubber modified high impact resins by dissolving a rubbery polymer in a monomer containing an aromatic vinyl monomer or a mixture of an aromatic vinyl monomer and a vinyl cyanide monomer followed by polymerizing the monomer, the two steps being carried out in at least two polymerization reactors with a particle disperser placed between the first and second reactors. High impact resins having excellent surface properties are obtained with a savings in a power consumption by controlling:(1) the relationship between the concentration of the polymerized monomer and the content of the rubbery polymer in the first reactor;(2) the relationship between the volume occupied by the polymerizing liquid in the first reactor and the inner volume of the particle disperser; and(3) the peripheral linear velocity of a shearing stirrer in the particle disperser.

Abstract: The invention relates to an improved process for producing a rubber-modified styrene resin, and a rubber-modified styrene resin composition resulting therefrom, such resin having improved mechanical strength, impact resistance and high gloss, such being accomplished by producing a rubber-modified styrene resin containing substantially no rubber particle having a density of not higher than 0.96 gm/cm.sup.3 at 25.degree. C.

Abstract: The present invention relates to rubber-modified styrene copolymer that exhibits excellent rigidity, impact strength, external appearance and fluidity, while retaining rigidity, impact properties and external appearance, and when prepared by copolymerizing a maleimide monomer, has high heat resistance and therefore is suitable for materials for components of electric equipments, electronic equipments, automobiles and business machines.

Abstract: A polyethylene composition which has excellent flow characteristics and mechanical properties, especially low temperature mechanical properties as well as thermal stability, elasticity and workability for molding. The polyethylene composition comprises 20 to 80 wt. % of an ethylene-.alpha.-olefin copolymer of higher molecular weight having (a) intrinsic viscosity (.eta..sub.1) of 1.2 to 9.0 dl/g, (b) density (d.sub.1) of 0.890 to 0.935 g/cm.sup.3 (c) a specific areal ratio calculated with an elution temperature-eluate volume curve in elution fractionation, and (d) a specific quantity of the content which is soluble in 25.degree. C. o-dichlorobenzene, and 80 to 20 wt. % of ethylene homopolymer or ethylene-.alpha.-olefin copolymer of lower molecular weight having (e) intrinsic viscosity (.eta..sub.2) of 0.2 to 1.6 dl/g, (f) density (d.sub.2) of 0.890 to 0.980 g/cm.sup.3 and, wherein the above (.eta..sub.1) is larger than (.eta..sub.2), and the prepared composition has an intrinsic viscosity (.eta.) of 0.

Abstract: A first reactor is used to graft polystyrene to a rubber-like polymer. A second reactor is used to obtain a mixture of styrene and polystyrene. The effluent from both the first and the second reactors are fed into a quiescent reaction zone where phase inversion occurs. The phase inverted material is fed into post inversion reactors to substantially complete the polymerization of the styrene monomer, and any unreacted styrene monomer is driven off to form the improved high-impact polystyrene.

Abstract: A substantially gel free C.sub.4 to C.sub.7 isoolefin homopolymer rubber, butyl copolymer rubber, halogenated butyl rubber (e.g., chlorinated or brominated), or mixtures thereof, comprising a molecular weight distribution such that the ratio of the moments of said molecular weight distribution, Mz/Mw, is equal to or exceeds 2.0, and that portion of said molecular weight distribution which is equal to and greater than 4 times the peak molecular weight, Mp, comprises greater than 8 percent of the total polymer species, and Mp is greater than about 250,000 and wherein said polymer species of molecular weight less than Mp are substantially branch free. Various means are disclosed for effecting the molecular weight distribution including blending of homopolymers and/or copolymers of appropriate molecular weight and molecular weight distribution and direct polymerization using a functional reagent to introduce branching.

Abstract: An improved method for preparing block copolymers of propylene which comprises providing a polymerizer composed of at least two reaction vessels connected to one another, substantially homopolymerizing propylene in a first step and then copolymerizing ethylene and propylene in a second step in the presence of a stereoregular catalyst, characterized by carrying out the homopolymerization of propylene in the polymerizer composed of at least two reaction vessels connected to one another in series, then introducing the resulting polymer slurry into a countercurrent washing column and countercurrently washing the slurry with propylene, introducing the washed slurry withdrawn from the lower part of the washing column into a reaction vessel in the second step connected to the washing column and performing the polymerization of ethylene and propylene, of which ratio ranges from 15/85 to 95/5. According to this method, a block copolymer of propylene exhibiting excellent physical properties can be obtained efficiently.

Abstract: In a method and apparatus for the production of thermoplastic, caprolactam containing molding compositions by hydrolytic polymerization of caprolactam in stirrer autoclaves in which a molten mass is polymerized at pressures of 5 to 20 bar and temperatures of 220.degree. to 280.degree. C., the molten mass is transferred into an intermediate vessel to which vacuum is applied for continued polymerization and removal of volatile portions. Subsequently, the mass is continuously fed into a multi-screw extruder, in order to attain at increased temperatures and vacuum the desired polymerization degree and the desired monomer and oligomer contents. In a subsequent zone of the extruder, when desired, additional agents are worked in, whereafter a further degasification occurs in the end zone of the extruder, whereafter the mass is extruded, quenched, subdivided and dried. The method and apparatus use relatively little energy as compared with the prior art.

Abstract: Process for the continuous bulk production of high impact vinylaromatic copolymers in which the vinylaromatic monomer, and if present, a comonomer selected from the group consisting of acrylonitrile, methacrylonitrile, acrylic acid, methacrylic acid and their alkyl- or cyclo-alkyl-esters containing from 1 to 8 carbon atoms in the alkyl group, the rubber, a part of the diluent solvent and the catalyst are premixed in a premixer at a temperature under 100.degree. C. and fed to a plug-flow agitated tubular reactor, which is divided into several stages or zones. The excess mixture is recycled to the premixer and the remaining part of the diluent solvent is injected into the top of the reactor to prevent the formation of incrustations. In the first zone of the reactor, the temperature and the residence time of the mixture are regulated so to have the halving the catalyst life.

Abstract: Disclosed herein is a continuous mass polymerization process for the preparation of acrylonitrile-butadiene-styrene-ester polymers (ABSE) having a balance of gloss, tensile strength, impact strength, processability and heat resistance properties.

Abstract: A styrene, isoprene, butadiene terpolymer rubber with a characterization according to its glass transition temperatures and unit structure and a pneumatic tire with a tread composed of such terpolymer rubber specifically in combination with selected other rubber.

Abstract: A process for the in situ blending of polymers comprising continuously contacting, under polymerization conditions, a mixture of ethylene and at least one alpha-olefin having at least 3 carbon atoms with a catalyst in at least two fluidized bed reactors connected in series, said catalyst comprising:(i) a complex consisting essentially of magnesium titanium, a halogen, and an electron donor;(ii) at least one activator compound for the complex having the formula AlR".sub.e X'.sub.f H.sub.g wherein X' is Cl or OR'"; R" and R'" are saturated aliphatic hydrocarbon radicals having 1 to 14 carbon atoms and are alike or different; f is 0 to 1.5; g is 0 or 1; and e+f+g=3; and(iii) a hydrocarbyl aluminum cocatalyst, the polmerization conditions being such that ethylene copolymer having a high melt index in the range of about 0.1 to about 1000 grams per 10 minutes is formed in at least one reactor and ethylene copolymer having a low melt index in the range of about 0.001 to about 1.

Abstract: Propylene-ethylene copolymers are prepared in an agitated bed of solids by first polymerizing propylene from the gas phase in a first polymerization zone at 20-40 bar and 60.degree.-90.degree. C. by addition of a Ziegler-Natta catalyst system, and copolymerizing in a second polymerization zone at 7-35 bar and 40.degree.-70.degree. C. the finely divided polymer from the first polymerization zone with a mixture of olefins a process which comprises copolymerizing in the second polymerization zone with a mixture of propylene, ethylene and a further .alpha.-olefin of from 4 to 10 carbon atoms, setting the ratio of the partial pressures between propylene and ethylene within the range from 100:20 to 100:120 and that of the partial pressures between propylene and the further .alpha.

Abstract: Continuous processes for producing high melting and viscoelasting polypropylene or ethylene-propylene copolymer are provided.These processes are characterized by (1) using two or more polymerizers connected in series, (2) supplying the whole amount of a catalyst and a molecular weight regulator (hydrogen) in the first tank and (3) a degasification amount of each tank in the second and subsequent tanks being 0.5 to 10 V.sub.1 /Hr (wherein V.sub.1 is a volume of the tank) calculated at 0.degree. C. and 0 Kg/cm.sup.2 G. In the process for producing the copolymer, (4) monomers having an ethylene content of 5 wt % or less are supplied in the first step. According to the processes of the present invention, polymers having a broad molecular weight distribution and good fluidity upon extrusion molding can be obtained and operational control in production is simply made.

Abstract: Ethylene/vinyl acetate copolymers containing very high molecular weight components and having a reduced tendency to tackiness may be obtained by a further addition of ethylene during the process of solution polymerization at a moderate pressure.

Abstract: A process for the in situ blending of polymers comprising continuously contacting, under polymerization conditions, a mixture of ethylene and at least one alpha-olefin having at least 3 carbon atoms with a catalyst in at least two fluidized bed reactors connected in series, said catalyst comprising:(i) a complex consisting essentially of magnesium titanium, a halogen, and an electron donor;(ii) at least one activator compound; and(iii) a hydrocarbyl aluminum cocatalyst, the polymerization conditions being such that ethylene copolymer having a high melt index in the range of about 0.1 to about 1000 grams per 10 minutes is formed in at least one reactor and ethylene copolymer having a low melt index in the range of about 0.001 to about 1.0 gram per 10 minutes is formed in at least one other reactor, each copolymer having a density of about 0.860 to about 0.965 gram per cubic centimeter and a melt flow ratio in the range of about 22 to about 70, and being admixed with active catalyst.

Abstract: In the gas phase, two stage process for the production of polypropylene impact copolymer, the fouling of the second stage recycle loop and the heat exchange unit incorporated therein is reduced by the addition to the substantially gaseous material passing through the loop of a small amount of alkylene compound selected from alkylene glycol compounds, alkylene glycol derivatives of alkylene diamines or ethers or esters thereof.

Abstract: An impact-resistant thermoplastic molding material which contains, based in each case on A+B, from 80 to 50% by weight of a hard matrix A of polystyrene having a molecular weight M.eta. of from 150,000 to 200,000 and from 50 to 20% by weight of a soft phase B which is uniformly distributed in the hard matrix and has a median particle diameter d.sub.50 (volume average) of from 1 to 10 .mu.m, and can be obtained by polymerizing styrene in the presence of an elastomeric grafting base, advantageously has a molecular weight of the grafted branches of from 1.1 to 1.35 times the molecular weight of the hard matrix, and the degree of grafting is from 50 to 100%.

Abstract: Stereoregular polymers having a molecular weight distribution of less than 5.0 and an isotactic index in excess of 96 percent are produced by polymerizing an alpha-olefin having 3 to 8 carbon atoms in a low pressure gas phase fluid bed process at a temperature in excess of 80.degree. C. employing a heat stable catalyst system comprising (a) a solid catalyst component containing magnesium, titanium, halide and a polycarboxylic acid ester containing two coplanar ester groups attached to adjacent carbon atoms, as inside electron donor, (b) an organoaluminum cocatalyst, and (c) a silicon compound containing a silicon-oxygen-carbon linkage, as outside electron donor.

Abstract: A process for the in situ blending of polymers comprising continuously contacting, under polymerization conditions, a mixture of ethylene and at least one alpha-olefin having at least 3 carbon atoms present in an amount of about 0.1 to 3.5 mole per mole of ethylene with a catalyst in at least two fluidized bed reactors connected in series, said catalyst comprising:(i) a complex consisting essentially of magnesium titanium, a halogen, and an electron donor;(ii) at least one activator compound for the complex having the formula A1R".sub.e X'.sub.f H.sub.g wherein X' is C1 or OR"'; R" and R"' are saturated aliphatic hydrocarbon radicals having 1 to 14 carbon atoms and are alike or different; f is 0 to 1.5; g is 0 or 1; and e+f+g=3; and(iii) a hydrocarbyl aluminum cocatalyst, the polymerization conditions being such that ethylene copolymer having a high melt index in the range of about 0.

Abstract: Polymer having a polymodal MWD ethylene copolymer are prepared by conducting the polymerization in a substantially mix free reactor using an essentially transfer agent free reaction mixture, the reaction being carried out in a manner such that the propagation of essentially all copolymer chains is initiated simultaneously. In carrying out the process of this invention, the catalyst components are premixed and aged prior to introduction into the reactor. The process is preferably carried out in a tubular reactor using VCl.sub.4 and aluminum sesquichloride as the catalyst system.

Abstract: Propylene/ethylene polymers are prepared by a process in which, in each case in the presence of hydrogen and by means of gas phase polymerization, first (A), in a first polymerization zone, propylene is homopolymerized, and the resulting propylene homopolymer is introduced into (B) a second polymerization zone, where a mixture of propylene and ethylene is then polymerized with the reaction product obtained in (A). In this process, ethylene is homopolymerized in a further polymerization zone (C), likewise by gas phase polymerization, with certain provisos, and the resulting reaction product is likewise fed to the second polymerization zone (B).

Abstract: Ionically crosslinked ethylene copolymers prepared by mixing a carboxyl-containing copolymer with an aqueous metal salt solution in the reaction zone of a twin-screw extruder and transferring the product to a devolatilization zone, and are used as adhesion promoters, injection molded articles or laminating films.

Abstract: A method for producing a propylene-.alpha.-olefin block copolymer, which comprises polymerizing propylene in the presence of a catalyst and then polymerizing in a gas phase an .alpha.-olefin other than propylene, or propylene and other .alpha.-olefin without deactivating the catalyst, wherein at least one compound selected from the group consisting of an aromatic carboxylic acid ester, a phosphorous ester, an unsaturated dicarboxylic acid diester, an amine compound and an amide compound, is supplied to the latter gas phase polymerization system.

Abstract: Propylene/ethylene block copolymers are prepared by a continuous process in which, in each case in an agitated fixed bed of finely divided polymer from the gas phase, first (I) in a first polymerization zone, propylene is homopolymerized by feeding in a Ziegler-Natta catalyst system consisting of (1) a titanium component which contains titanium, magnesium, chlorine and a phthalic acid derivative, (2) an aluminumalkyl component and (3) a silane component, and (II) in a second polymerization zone, a mixture of propylene and ethylene is polymerized with the propylene homopolymer present in the reaction mixture obtained in the first polymerization zone by feeding in the said reaction mixture. In the process, (A) a titanium component (1) is used which is obtained by a method in which (1.1) first, (1.1.1) in a liquid hydrocarbon, (1.1.2) a finely divided magnesium halide, (1.1.3) an alkanol, (1.1.4) a certain phthalic acid derivative and (1.1.

Abstract: Ethylene is polymerized, optionally with a small amount of an .alpha.-olefin, in the presence of a Ziegler catalyst in multiple stages by using a polymerization apparatus including at least three polymerization reactors. In the polymerization process, the following three ethylene polymer components U, H and L are prepared sequentially in an optional order; a component U having an .alpha.-olefin content .alpha..sub.U of 0.1-10 wt. % and an intrinsic viscosity [.eta.].sub.U satisfying 2.times.[.eta.].sub.W .ltoreq.[.eta.].sub.U .ltoreq.5.times.[.eta.].sub.W in which [.eta.].sub.W is the intrinsic viscosity of the entire ethylene polymer, the ratio R.sub.U of component U in the entire ethylene polymer satisfying 0.3.times.[.eta.].sub.W .ltoreq.[.eta.].sub.U .times.R.sub.U .ltoreq.0.8.times.[.eta.].sub.W ; a component H having an .alpha.-olefin content .alpha..sub.H of up to 20 wt. % and an intrinsic viscosity [.eta.].sub.H satisfying ([.eta.].sub.W).sup.1/2 .ltoreq.[.eta.].sub.H .ltoreq.1.5.times. [.eta.].sub.

Abstract: Continuous processes for producing high melting and viscoelasting polypropylene or ethylene-propylene copolymer are provided.These processes are characterized by (1) using two or more polymerizers connected in series, (2) supplying the whole amount of a catalyst and a molecular weight regulator (hydrogen) in the first tank and (3) a degasification amount of each tank in the second and subsequent tanks being 0.5 to 10 V.sub.1 /Hr (wherein V.sub.1 is a volume of the tank) calculated at 0.degree. C., and 0 Kg/cm.sup.2 G. In the process for producing the copolymer, (4) monomers having an ethylene content of 5 wt % or less are supplied in the first step. According to the processes of the present invention, polymers having a broad molecular weight distribution and good fluidity upon extrusion molding can be obtained and operational control in production is simply made.

Abstract: In a process for producing a high impact styrene resin by continuously polymerizing a styrene monomer in bulk in the presence of a rubbery polymer, the improvement whereina polymerization line is used which is comprised of an initial-stage polymerization line (II) following a material feed line (I) and consisting of one or more tubular reactors having fixedly set therein a plurality of mixing elements having no moving parts, a main polymerization line (III) following the initial-stage polymerization line (II) and consisting of one or more tubular reactors having fixedly set therein a plurality of mixing elements having no moving parts, and a recycle line (IV) which branches between the initial-stage polymerization line (II) and the main polymerization line (III) and returns to the initial-stage polymerization line (II), anda minor part or a major part of a flow of the initial-stage polymer solution leaving the initial-stage polymerization line (II) is recycled through the recycle line (IV) while the remaining

Abstract: Process for the continuous production in solution of styrene thermoplastic resins by polymerization of a vinyl-aromatic monomer and of a vinyl-nitrile monomer in the presence of an elastomer and of a starter, wherein polymerization is conducted in two or more steps, wherein the elastomeric component is fed, in solution in the solvent and/or in the monomers, to the first step, polymerization is carried out in the subsequent steps at temperatures ranging from 70.degree. to 150.degree. C., in each step the reaction mass is gently and homogeneously stirred and the reaction product is caused to flow to a thin evaporator heated at 150.degree.-300.degree. C.

Abstract: A block copolymer of propylene can be obtained with its quality controlled uniform by conducting at first continuous polymerization of propylene in a polymerization system, receiving a polymer slurry, which has been discharged continuously from the polymerization system, in a batchwise polymerization tank, feeding ethylene to the tank to conduct batchwise polymerization of ethylene and propylene. Upon discharge of a copolymer slurry formed by the preceding batchwise polymerization, at least a predetermined amount of unreacted ethylene is left over in the tank. Into the tank with the unreacted ethylene still left over therein, there are simultaneously charged the polymer slurry from the polymerization system and a deactivator. During this charging, ethylene is not supplied.

Abstract: The invention relates to a process for the preparation of a thermoplastic polymer on the basis of an alkenyl aromatic monomer, an unsaturated dicarboxylic anhydride, and, optionally, a rubber, characterized in that the monomers and/or solution thereof are/is reacted in at least two reaction zones that are in open connection with each other at the top and at the bottom, the reaction mixture being circulated through the reaction zones by means of a mixing device and/or a conveying device.Using the process, a homogeneous product of constant composition is obtained.

Abstract: A process for the production of a product comprising ethylene/propylene copolymer incorporated into a matrix of propylene homopolymer or copolymer comprising the following steps:(a) contacting propylene or propylene and at least one alpha-olefin having 2 to 8 carbon atoms, and hydrogen, wherein the alpha-olefin is present in a ratio of about 0.01 to about 0.06 mole of alpha-olefin per mole of propylene and the hydrogen is present in a ratio of about 0.001 to about 0.

Abstract: The present invention relates to polymeric composition of a first copolymer which includes at least one copolymer having at least one of Mw/Mn less than 2 and Mz/Mw less than 1.8; and a second copolymer having Mw/Mn greater than or equal to 2. The composition can be produced by preparing the first and second copolymers in different reactors and blending them. The blend can also be produced in a single reactor by initiating the reaction to prepare one copolymer, and adding additional reactants, or recycling the reaction mixture, during the reaction to produce the other copolymer.

Abstract: A continuous flow process for the production of high impact polystyrene, wherein specific types of polymerization inhibiting impurities are removed from a recycle stream prior to feeding or introducing the recycle stream into a styrene polymerization zone. Preferably, the process further comprises the step of monitoring the acidity of the recycle stream.