Abstract: A process for the preparation of resin particles comprising: heating a mixture comprised of a free radical initiator compound, at least one stable free radical compound, at least one free radical polymerizable monomer compound, and at least one free radical polymerizable crosslinking compound; and cooling the mixture, wherein the resulting product resin particles are crosslinked and are comprised of polymerized monomers and at least one crosslinking compound, and wherein the particles have a narrow particle size distribution, a narrow pore size distribution, and a high monomer to polymer conversion.

Abstract: Acrolein polymer from acrolein and one or more polyhydric alcohols, characterized by release of monomeric acrolein in aqueous systems and hence by a prolonged effect on microorganisms, is prepared by adding acrolein to a reaction medium containing catalyst in dissolved form, and not allowing the temperature of the reaction medium to rise about 50.degree. C. The acrolein polymer may be used in aqueous systems as a biocide.

Abstract: The present invention provides a polymerizable monomer composition particle and a resin particle, both of which display a narrow particle diameter distribution. A process for producing a resin particle comprises the steps of: passing two liquids through a static type in-line mixer having a liquid-dividing mechanism standing in a static state, wherein the two liquids are formable into two phases including one of the two liquids as a dispersing phase component and the other as a continuous phase component; then passing the two liquids through a high speed shearing type dispersing machine having a liquid-shearing mechanism which revolves at a high speed, thus dispersing a fine liquid drop of the dispersing phase component into the continuous phase component; and forming a resin particle from the resultant liquid drop.

Abstract: Particulate, filterable polystyrene formulations are obtained by anionic polymerization of styrene in nonaqueous dispersion if the polymerization is carried out in an aliphatic hydrocarbon as the dispersing medium and with a styrene/diene/styrene three-block copolymer, for example based on polybutadiene or polyisoprene, as the dispersant.

Abstract: Fine particles (having a particle diameter smaller than 10 .mu.m) of crosslinked acrylonitrile polymer capable of absorbing and releasing a large amount of moisture, in which the acrylonitrile polymer is crosslinked with hydrazine such that the nitrogen content increases by 1.0-15.0 wt % and there being introduced salt type carboxyl groups in an amount of 1.0 mmol/g or more into a part of the remaining nitrile groups. Said fine particles are prepared by treating an emulsion of acrylonitrile polymer with hydrazine so that crosslinks are formed in the acrylonitrile polymer and the nitrogen content increases by 1.0-15.0 wt % and then hydrolyzing the crosslinked acrylonitrile polymer so as to introduce more than 1.0 mmol/g of carboxyl groups in salt form into nitrile groups remaining uncrosslinked and to introduce amide groups to the rest of nitrile groups.

Abstract: This invention provides latex compositions prepared using, for example, both acetoacetoxyethyl methacrylate (AAEM) and t-butylaminoethyl methacrylate (t-BAMA) which when applied to a pre-coated substrate, possess out-standing wet adhesion when compared to waterborne polymers containing either AAEM or t-butylaminoethyl methacrylate alone. The latex compositions of this invention continue to exhibit superior wet adhesion after storage at room temperature for one year. The latex compositions are thus particularly useful in coating compositions, especially coating bare or previously-coated metals, paper, plastics, wood, textiles, and in adhesives.

Abstract: The invention relates to a method for the production of poly(meth) acrylate particles with a particle diameter of 1-15 .mu.m, where the monomers M are polymerized according to the method of batch polymerization, with 20-50 parts by weight of monomer M in a liquid medium LM, consisting of 55-100% by weight of mineral oil, and with the addition of 0.1 to 5 parts by weight of a polymer emulsifier E and 0.05-5 parts by weight of a radical initiator.

Abstract: An improved process for preparing core/shell MBS modifiers is disclosed, wherein by adding feeds of the monomers which form the second and/or third stage polymers prior to completion of polymerization of the earlier stages, a process with substantially reduced polymerization time results with no loss in properties of the product. The process further includes agglomeration of the rubbery polymer to increase particle size during the polymerization process.

Abstract: Aqueous acrylic polymer compositions comprising a copolymer of an alkyl acrylate, an alkyl methacrylate and one or more acrylate acids or salts thereof are disclosed. By introducing an alkoxylated surfactant having a surface tension of greater than about 32.2 dynes/cm and less than 48.2 dynes/cm, enhanced freeze-thaw stability can be obtained with the polymer compositions of the present invention. The polymer compositions are compatible in all-aqueous hairspray compositions, as well as those which contain up to about 80 weight percent volatile organic compounds, or more.

Abstract: Vinyl polymers, e.g., the homo- and copolyvinyl chlorides, are prepared in one or more stages, to a degree of conversion of at least 50%, by suspended emulsion polymerizing at least one vinyl monomer, e.g., vinyl chloride, said at least one monomer having dispersed therein finely divided droplets of an aqueous solution of at least one component of a polymerization initiating system, and wherein the amount of water in said aqueous solution constitutes at least 19%, and preferably at least 20% by weight of the at least one monomer.

Abstract: A process of making polymeric matte bead particles for use in photographic elements which comprises forming a suspension of ethylenically unsaturated monomer droplets in an aqueous media, subsequent to the formation of droplets and before commencement of reaction, adding to the aqueous media an effective amount of a hydrophilic colloid to improve adhesion and polymerizing the monomer to form solid polymeric particles.

Abstract: The present invention provides new non-spherical microparticles. The microparticles are a hemisphere or a half elliptic sphere having a big opening at the central portion, say bowl-shape microparticles, and a water uptake of from 80 to 140 ml/100 g, which can be produced by suspension polymerization of polymerizable monomers in the presence of crosslinking agents and hydrophobic liquids in water. The microparticle of the present invention has an excellent extending ability, adhesiveness and water uptake. The new bowl-shape microparticles having the big opening at the center can be easily produced according to the present invention, and the size and shape can be easily controlled.

Abstract: The invention provides inherently tacky, polymeric, organic, solvent-insoluble, solvent dispersible, elastomeric, pressure sensitive adhesive microspheres having pendant hydrophilic polymeric or oligomeric moieties having a degree of polymerization greater than or equal to 2. The microspheres which are sterically stabilized can offer enhanced stability against coagulation caused by alkali, alkali salts, polyelectrolytes and repeated freeze/thaw cycles. The present invention also provides pressure-sensitive adhesives comprising these microspheres including aerosol spray PSAs, coated sheet materials prepared therefrom, and method of making the microspheres.

Abstract: A film of a linear low density copolymer of ethylene (LLDPE) having excellent processability, optical properties and impact strength, which exhibits a density of at least 0.900.

Abstract: A method of manufacturing pigment containing polymer particles comprises the steps of dissolving a surface active agent in a water at concentration higher than the CMC, dispersing a pigment, diluting the suspension at the concentration not higher than the CMC, and adding a monomer and a polymerization initiator for forming the pigment-containing polymer particles.

Abstract: Aqueous, anionic, acrylic polymer compositions comprising a copolymer of an alkyl acrylate, an alkyl methacrylate and one or more acrylate acids or salts thereof is disclosed. By controlling the particle size of the copolymer and introducing a surfactant, enhanced freeze-thaw stability can be obtained with the polymer compositions of the present invention. The polymer compositions are compatible in all-aqueous hairspray compositions, as well as those which contain up to about 80 weight percent volatile organic compounds, or more.

Abstract: It is possible to obtain globular polymers in the polymerization of alpha-olefins by means of a highly active, spherical Ziegler catalyst. The polymers have a high bulk density and can be processed very easily.

Abstract: Porous particles of MgCl.sub.2 which have essentially the shape of two truncated right cones connected by their larger bases, which truncated cones are incurved towards the axis of symmetry perpendicular to the bases, at the intersection of the envelope of the truncated cones with two orthogonal planes passing through the said axis of symmetry. These particles are impregnated with a transition metal compound and employed as a catalytic component in the polymerization of olefins. The resultant polyolefins, especially polyethylene, polypropylene and their copolymers, are comprised of particles with a distinctive structure.

Abstract: A fine particulate crosslinked type N-vinylcarboxylic acid amide resin having an average particle size of 10 .mu.m or less comprising backbone chains of a homopolymer or copolymer comprising repeating units (A) or (A) and (B) of the formulae: ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 each independently represent a hydrogen atom or methyl group; X represents a group --COOY, wherein Y represents a hydrogen atom, an alkali metal, a C.sub.1 -C.sub.

Abstract: Disclosed is a thermoplastic olefin polymer having elastic properties comprisinga) greater than 60 to 85 parts of a crystalline polymer fraction selected from the group consisting of (i) a copolymer of propylene and at least one alpha-olefin, (ii) a polybutene-1, (iii) an ethylene homopolymer or ethylene/alpha-olefin copolymer, (iv) polymer fraction (i), (ii) or (iii) in combination with, or mixtures thereof alone or in combination with, from 10 to 90 parts, based on the thermoplastic olefin polymer, of a homopolymer of propylene;b) from about 1 up to less than 15 parts of a semi-crystalline, low density, essentially linear copolymer fraction consisting substantially of units of the alpha-olefin used to prepare c) or the alpha-olefin used to prepare c) present in the greatest amount when two alpha-olefins are used; andc) from about 10 to less than 39 parts of an amorphous copolymer fraction of an alpha-olefin and propylene, with or without a diene or a different alpha-olefin termonomer.

Abstract: Novel ionomers of normally solid, thermo-plastic, orientable, copolymers of ethylene and at least one alpha,beta-ethylenically-unsaturated carboxylic acid having a relatively high content of the carboxylic acid are prepared under conditions whereby the copolymers are essentially solubilized in a strong base and contacted with at least one compound which contains ionomer-forming cations. One of the preferred polymers is an ethylene/acrylic acid copolymer. The so-formed ionomers are useful as materials for constructing various items and articles.

Abstract: Cation-exchange resins are provided which have improved resistance to copolymer degradation caused by oxidizing agents like molecular oxygen. The resins are prepared by incorporating a para-substituted styrenic monomer having an oxidation-stabilizing moiety in a position para to a polymerizable vinyl moiety. These cation-exchange resins can be used in separation processes for longer periods of time without detrimental increases in bed pressure drops, loss of operating capacity, or leaching of organic contaminants.

Abstract: Polypropylene compositions having valued plasto-elastic properties, in the form of spheroidal flowable particles with an average diameter included between 500 and 7000 um having the following composition:A) 10-60 parts by weight of homopolymer polypropylene with isotactic index greater than 90, or of crystalline propylene copolymer with ethylene and/or an alpha olefin such as butene-1, pentene-1 or 4-methyl-1-pentene, containing over 85% by weight of propylene and having an isotactic index greater than 85;B) 10-40 parts by weight of a polymer fraction containing ethylene, insoluble in xylene at room temperature;C) 30-60 parts by weight of an amorphous copolymer ethylene-propylene fraction optionally containing small proportions of a diene, soluble in xylene at room temperature and containing 40-70% by weight of ethylene.

Abstract: A fine particulate crosslinked type N-vinylcarboxylic acid amide resin having an average particle size of 10 .mu.m or less comprising backbone chains of a homopolymer or copolymer comprising repeating units (A) or (A) and (B) of the formulae: ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 each independently represent a hydrogen atom or methyl group; X represents a group --COOY, wherein Y represents a hydrogen atom, an alkali metal, a C.sub.1 -C.sub.

Abstract: A supported Ziegler-Natta catalyst active in ethylene polymerization and in the copolymerization of ethylene with alpha-olefins consists of:(A) a cocatalyst in the form of an organometallic compound of aluminium, and(B) a solid catalyst component obtained by:(i) impregnating a granular solid support with a solution of a titanium alcoholate and magnesium chloride in a liquid aliphatic hydrocarbon, followed by evaporation of the hydrocarbon solvent;(ii) impregnating the support treated in (i) with a solution of magnesium chloride in a liquid aliphatic ester, followed by evaporation of the ester solvent; and(iii) activating the support treated in (ii) by contact with an alkyl aluminium halide.In a preferred embodiment, measured quantities of a silicon halide are introduced in stage (i) and/or (ii), this considerably improving catalytic activity.

Abstract: A process for (co)polymerizing alpha-olefins in the gas phase in a fluidized bed or mechanically stirred bed reactor using a Ziegler-Natta type catalyst or a heat activated chromium oxide/refractory oxide catalyst wherein the (co)polymerization is carried out in the presence of 0.005 to 0.2 weight %, based on the weight of the (co)polymer bed, of an inert pulverulent inorganic substance (e.g. silica) having a mean particle diameter between 0.5 and 20 microns. The process is capable of being operated at temperatures closer to the softening point of the produced polyolefin than in the absence of the pulverulent solid.

Abstract: A process for producing monodispersed fine particles of a vinyl polymer is disclosed, which comprises polymerizing monomers containing at least one vinyl monomer selected from the group consisting of aromatic vinyl compounds, acrylic esters, and a methacrylic ester in the presence of (1) a surface active agent represented by formula (I) ##STR1## wherein R.sub.1 and R.sub.2, which may be the same or different, each represents a substituted or unsubstituted alkyl group having from 4 to 8 carbon atoms, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted cyclohexyl group and M represents an alkali metal, (2) from 10.sup.-3 to 10.sup.-1 mol/l of a persulfate as a polymerization initiator, and (3) from 10.sup.-4 to 10.sup.-2 mol/l of a divalent metal sulfate as an electrolyte. Monodispersed vinyl polymer fine particles having a particle size of 1 .mu.m or greater with a very narrow size distribution are obtained.

Abstract: Disclosed are a polymer gel in which a phase transition occurs due to a stimulus, a method of manufacturing such a polymer gel, and an actuator which employs such a polymer gel. The polymer gel which is formed by polymerizing monomers at a temperature equal to or less than a phase transition temperature of the resultant polymer gel and separating and/or classifying the polymer gel into fractions according to its size at a temperature equal to or greater than the phase transition temperature thereof. Alternatively, the polymer gel is separated and/or classified into fractions by adding a low molecular weight compound that can dissolve and swell the polymer gel to separate the polymer gel into fractions based upon a difference in dissolving rate or swelling rate. Alternatively separation and/or classification of the polymer gel is performed by a combination of the above-described two methods. In consequence, the resultant polymer gel has an average particle size ranging from 0.1 .mu.m to 100 .mu.

Abstract: A process for producing a polyolefin, which comprises polymerizing at least one olefin in the presence of a catalyst system comprising (A) a solid catalyst component (A) obtained by reacting to a uniform solution containing (i) at least one member selected from the group consisting of metallic magnesium and an organic hydroxide compound, and an oxygen-containing organic magnesium compound, and (ii) at least one oxygen containing organic titanium compound, (iii) at least one organic aluminum compound, (iv) at least one boron compound having an alkoxy group, and (v) at least one aluminum halide compound; and (B) at least one catalyst component (B) selected from the group consisting of organic metal compounds of metals of Groups Ia, IIa, IIb, IIIb and IVb of the Periodic Table.

Abstract: Finely divided, gel-like, water-swellable copolymers are prepared by copolymerizing(a) 100 parts by weight of water-soluble, monoethylenically unsaturated monomers,(b) from 0.01 to 5 parts by weight of monomers containing two or more ethylenically unsaturated double bonds and(c) from 0 to 20 parts by weight of water-insoluble, monoethylenically unsaturated monomersin 20-80% strength by weight aqueous solution in the presence of a polymerization initiator and from 0.1 to 10% by weight, based on the monomers used in the copolymerization, of a surfactant, by a process in which the monomers are copolymerized in the presence of initially from 0 to 50% by weight of the amount of surfactant to a conversion of not less than 60%, the remaining amount of surfactant is then added to the reaction mixture and the copolymerization is completed and the resulting gel particles dried.

Abstract: A method of manufacturing a polyolefin using a catalyst system of an ingredient (A) and ingredient (B), with ingredient A being obtained through successive reaction steps. Ingredient A is prepared by forming a mixture of (1) the combination of (a) metallic magnesium or an oxygen-containing organic compound of magnesium with (b) a mixture of a monohydroxylated organic compound and a polyhydroxylated organic compound, (2) oxygen-containing organic compounds of titanium and (3) at least one alpha-olefin having at least 4 cargon atoms, such as 1-hexene. The resulting solution is reacted in sequence with (4) at least one first halogenated aluminum compound, (5) at least one silicon compound and (6) at least one second halogenated aluminum compound. Ingredient B is an organometallic compound of metals from Group Ia, IIa, IIIa or IVa of the Periodic Table. The resulting free-flowing polyolefin is characterized by a large average particle size and small amount of fine particles.

Abstract: A method of preparing polymer particles having narrow size distribution in a suspension process employing a solid colloidal stabilizing agent. The solid colloidal stabilizer is a copolymer of about 25 to about 80% by weight, based on total monomer weight, of an addition polymerizable nonionic oleophilic monomer, about 5 to about 45%, by weight, of an addition polymerizable nonionic hydrophilic monomer, about 1 to about 50% of an addition polymerizable ionic monomer, and 0 to about 20 percent, by weight, of a crosslinking monomer having at least two addition polymerizable groups. Also disclosed are polymeric particles comprising a core polymer covered by a layer of the smaller copolymer stabilizer particles and electrostatographic toners comprising such polymeric particles.

Abstract: An improved process for producing an ethylene copolymer composed of a major proportion of ethylene and a minor proportion of an alpha-olefin having 3 to 10 carbon atoms and having a density of 0.910 to 0.945 g/cm.sup.3 and an ethylene content of 85 to 99.5 mole %. The use of a titanium catalyst component (A) which meets a parametric combination of specific requirements is essential in this process. The process can industrially advantageously give a low to medium density ethylene copolymer of high quality with high productivity while advantageously circumventing the operational troubles which have been difficult to avoid by conventional processes.

Abstract: The invention relates to a process for the preparation of a predominantly crystalline ethylene/propylene copolymer having less than 15 mol % of propylene units, which can be carried out in liquid propylene as the suspending agent, if metallocene catalyst components of the formulae I, II or III are employed and the partial pressures of ethylene and propylene have a specific ratio. ##STR1## By means of this process, it is possible to increase the possible uses of polymerization plants which work with liquid propylene.

Abstract: A catalyst comprising (A) a solid catalyst component obained by reacting a homogeneous solution containing (i) at least one member selected from the group consisting of a combination of metallic magnesium and a hydroxyl organic compound, and an oxygen-containing organic compound of magnesium, (ii) an electron donor compound and (iii) an oxygen-containing organic compound of titanium with (iv) at least one aluminum halide compound and further reacting the obtained solid product with (v) an electron donor compound and (vi) a titanium halide compound, (B) at least one member selected from the group consisting of organic metal compounds of metals of the groups Ia, IIa, IIb, IIIb and IVb of the periodic table, and (C) an electron donor compound, is valuable as the catalyst for preparing a stereoregular polyolefin by homopolymerization or copolymerization of an .alpha.-olefin having at least 3 carbon atoms.

Abstract: Vinyl polymers, e.g., the homo- and copolyvinyl chlorides, are prepared in one or more stages, to a degree of conversion of at least 50%, by suspended emulsion polymerizing at least one vinyl monomer, e.g., vinyl chloride, said at least one monomer having dispersed therein finely divided droplets of an aqueous solution of at least one component of a polymerization initiating system, and wherein the amount of water in said aqueous solution constitutes at least 19%, and preferably at least 20% by weight of the at least one monomer.

Abstract: Polymers of propene are prepared by means of a Ziegler-Natta catalyst system composed of (1) a titanium component based on a finely divided shape-dictating silica gel and containing titanium, magnesium, chlorine and a benzenecarboxylic acid derivative, (2) an aluminum component and (3) a silane component, the titanium component (1) being obtained by (1.1) first preparing (I) a carrier material from (Ia) a silica gel, (Ib) an organomagnesium compound (Ic) a gaseous chlorinating agent and (Id) a specific phthalic acid derivative by (1.1.1) first reacting (Ia) with (Ib), then (1.1.2) passing (Ic) into the product of (1.1.1) together with the phthalic acid derivative (Id) and isolating (I), (1.2) preparing a solid-phase intermediate from (I), (II) an alkanol and (III) titanium tetrachloride by (1.2.1) first reacting (I) with (II), then (1.2.2) introducing (III) into the product resulting from (1.2.1), then (1.3) extracting the solid-phase result from (1.

Abstract: A toner for developing electrostatic images and a process for producing the same is disclosed. The process comprises after applying ultrasonic waves to raw materials-mixture comprising addition polymerizable monomer(s), coloring agent(s) and water as indispensable components in the course of charging the raw materials-mixture into a reaction vessel or to a raw materials-mixture in a reaction vessel, at an application amount of from 0.05 to 50 W/l/hr. per unit treating volume and time using an ultrasonic homogenizer having frequencies of from 10 kHz to 50 kHz, subjecting the raw materials-mixture to suspension polymerization.

Abstract: Monodisperse, polymeric microspheres are formed by injecting uniformly shaped droplets of radiation polymerizable monomers, preferably a biocompatible monomer, having covalent binding sites such as hydroxyethylmethacrylate, into a zone, impressing a like charge on the droplet so that they mutually repel each other, spheroidizing the droplets within the zone and collecting the droplets in a pool of cryogenic liquid. As the droplets enter the liquid, they freeze into solid, glassy microspheres, which vaporizes a portion of the cryogenic liquid to form a layer. The like-charged microspheres, suspended within the layer, move to the edge of the vessel holding the pool, are discharged, fall and are collected. The collected microspheres are irradiated while frozen in the cryogenic liquid to form latent free radicals. The frozen microspheres are then slowly thawed to activate the free radicals which polymerize the monomer to form evenly-sized, evenly-shaped, monodisperse polymeric microspheres.

Abstract: Ultra-high-molecular-weight polyolefin fine powder characterized in that said fine powder has an intrinsic viscosity measured in decalin at 135.degree. C. of at least 10 dl/g and an average particle diameter in the range of 1-80 .mu.m, at least 20 weight % of the powder passing through 350 Tyler mesh screen.

Abstract: Resinous microparticles useful in toner for electrophotography which are made of vinyl resin obtained by emulsion polymerization of at least one .alpha.,.beta.-ethylenically unsaturated monomers in the presence of cationic surfactant having an onium salt structure and a polymerization initiator having an amidine or amidine salt structure and whose average particle diameter is in a range of from 0.01 to 1.mu., and toner composition comprising toner particles and resinous microparticles as abovementioned are provided.

Abstract: A solid titanium catalyst component (A) of a catalyst system useful in the polymerization of olefins or copolymerization of two or more olefins or one or more olefins and a diene is prepared by contacting a liquid hydrocarbon solution of (i) a magnesium compound, such as magnesium chloride, with (ii) a liquid titanium compound, such as TiCl.sub.4, or a solution of a titanium compound in a hydrocarbon solvent, to form a solid product. The solid product is formed in the presence of (D) an electron donor, e.g. methyl formate, acetic acid, acetic anhydride, acetone, methyl ether, butyl Cellosolve, dimethyl carbonate, methyl silicate. The solid product is also contacted with a polycarboxylic acid ester, e.g. diethyl methylsuccinate. The polymerization or copolymerization of the olefin is carried out in the presence of the solid titanium catalyst (A) and (B) an organometallic compound of a Group I to III metal and (C) an organic silicon compound having an Si--O--C bond.

Abstract: A method of carrying out a continuous aqueous emulsion copolymerization using a single continuously stirred tank reactor to reduce the particle size distribution and the presence of over-sized particles comprises, slowly supplying to a reactor the materials used in the copolymerization, including the monomers which are copolymerized, while maintaining conditions causing copolymerization to proceed until the reactor is filled. The supply is continued while maintaining those conditions until the total supply is in the range of from about 1.5 to about 5 reactor volumes. The excess material in the reactor is removed therefrom and collected in one or more separate vessels, and the product of the copolymerization is then combined and mixed to form a uniform product. The composition copolymerized can be changed during the copolymerization. The emulsion copolymer product is particularly useful in latex paints where it improves the gloss and scrub resistance of the paint.

Abstract: The viscosity of the dispersing medium, such as cyclohexane, in the anionic dispersion polymerization of monomers, such as styrene, is increased by adding a higher viscosity inert miscible liquid, such as hexadecane, or a soluble inert solid, or by using a liquid having a viscosity of greater than about 2 cp. The increased viscosity assists in the formation of dispersed polymer particles having a narrower particle size distribution than those produced in the lower viscosity dispersing medium.

Abstract: A process for producing monodispersed fine particles of a vinyl polymer is disclosed, which comprises polymerizing monomers containing at least one vinyl monomer selected from the group consisting of aromatic vinyl compounds, acrylic esters, and a methacrylic ester in the presence of (1) a surface active agent represented by formula (I) ##STR1## wherein R.sub.1 and R.sub.2, which may be the same or different, each represents a substituted or unsubstituted alkyl group having from 4 to 8 carbon atoms, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted cyclohexyl group and M represents an alkali metal, (2) from 10.sup.-3 to 10.sup.-1 mol/l of a persulfate as a polymerization initiator, and (3) from 10.sup.-4 to 10.sup.-2 mol/l of a divalent metal sulfate as an electrolyte. Monodispersed vinyl polymer fine particles having a particle size of 1 .mu.m or greater with a very narrow size distribution are obtained.

Abstract: A process for producing monodisperse vinyl polymer fine particles is disclosed, which comprises polymerizing at least one monomer selected from the group consisting of vinyl aromatic compounds, acrylic esters, and methacrylic esters as dissolved in an organic solvent or a mixed solvent of water and an organic solvent, which is capable of dissolving said monomer or monomers but incapable of dissolving a produced polymer, wherein said polymerizing is carried out in the presence of partially saponified polyvinyl alcohol having a degree of saponification of from 5 to 75 mol % and a number average degree of polymerization of from 100 to 3,000 as a dispersion stabilizer and in the presence of a polymerization initiator. Monodisperse polymer particles having a particle size of the order of micron with a narrow size distribution can be obtained through the one-step polymerization.

Abstract: A method for producing an olefin polymer, which comprises polymerizing or copolymerizing olefins in the presence of a catalyst comprising:(A) a solid catalyst component obtained by thermally reacting (a.sub.1) a magnesium compound of the formula Mg(OR.sup.1).sub.n (OR.sup.2).sub.2-n wherein each of R.sup.1 and R.sup.2 which may be the same or different is an alkyl group, an aryl group or an aralkyl group, and n is 2.gtoreq.n.gtoreq.0, (a.sub.2) a titanium compound of the formula Ti(OR.sup.3).sub.4 wherein R.sup.3 is an alkyl group, an aryl group or an aralkyl group and (a.sub.3) a silicon compound of the formula Si(OR.sup.4).sub.4 wherein R.sup.4 is an alkyl group, an aryl group or an aralkyl group and contacting and treating (a) the resulting thermal reaction product with (b) a halogen-containing titanium compound and (c) an electron donative compound, and(B) an organometallic compound of a metal of Groups I-III of the Periodic Table.

Abstract: The present invention relates to a process for the polymerisation or copolymerisation of alpha-olefins in the presence of a Ziegler-Natta catalyst system comprising on the one hand a catalyst solid comprising compounds of halogens, transition metals of Groups IV, V, VI of the Periodic Table of Elements, magnesium and optionally aluminum, free from a metal/carbon bond and on the other hand a catalyst consisting of organometallic compounds of metals of Group II or III of the said Table. This process is characterised in that before its use in polymerisation or copolymerisation, the catalyst solid is treated by water in a given quantity, this treatment making it possible to improve the conditions for obtaining polymers, particularly in a process of polymerisation or copolymerisation in the gas phase.

Abstract: A method of producing polymer particles having a particle size distribution of .+-.25% with respect to each average particle size in an amount of 95 wt. % or more, within the average particle sizes ranging from 1 .mu.m to 100 .mu.m, is disclosed, which comprises the steps of: (1) adding a polymer dispersion stabilizer in an amount of 0.1 to 10 wt. % to a hydrophilic organic liquid in which the polymeric dispersion stabilizer is soluble; (2) adding thereto at least one vinyl monomer in an amount of not more than 50 times by weight the amount of the polymeric dispersion stabilizer, which monomer is soluble in the hydrophilic organic liquid, but a polymer synthesized from the monomer being swelled or substantially insoluble in the hydrophilic organic liquid; and (3) polymerizing the monomer under the condition that the amount of the vinyl monomer is 200 wt. % or less of the hydrophilic organic liquid.

Abstract: A method for producing an olefin polymer, which comprises polymerizing or copolymerizing an olefin in the presence of a catalyst comprising (a) a titanium-containing solid catalyst component and (b) an organic metal compound of a metal of Groups I-III of the Periodic Table, said solid catalyst component (a) being obtained by treating (A) a magnesium compound of the formula Mg(OR.sup.1).sub.n (OR.sup.2).sub.2-n wherein each of R.sup.1 and R.sup.2 is an alkyl group, an aryl group or an aralkyl group, and n is 2.gtoreq.n.gtoreq.0, with three compounds i.e. (B) an electron donative compound, (C) a silicon compound of the formula Si(OR.sup.3).sub.4 wherein R.sup.3 is an alkyl group, an aryl group or an aralkyl group and (D) a titanium compound.