Abstract: These crosslinked microparticles between 10-300 nm in size are obtained by dispersion polymerization, in non-aqueous medium which is non-solvent for the polymer formed, of a composition of ethylenically unsaturated polymerizable compounds, comprising: at least one monomer A, comprising only one ethylenic unsaturation, giving the microparticles formed in the said non-aqueous medium self-stabilization during and after polymerization, without any addition of polymer having the function of a stabilizing agent, tither before, during or after polymerization, at least one compound B comprising at least two ethylenic unsaturations and optionally, depending on the case: at least one compound C comprising only one ethylenic unsaturation and/or at least one compound D which is different from A, B and C and comprising at least one ethylenic unsaturation which can undergo radical-mediated polymerization and at least one second reactive function f1 which is other than an ethylenic unsaturation.

Abstract: The present invention is directed to a polymeric composition including a poly(alkenyl-co-maleimide) and an inorganic salt. Optionally, an extender is included. The composition exhibits good strength and vibration damping properties.

Abstract: Combinations of polymer compounds and hair treatment compositions containing them are described, which have improved film-forming properties and improved hair-fixing properties, particularly increased elasticity of the polymer film or the treated hair. The polymer compound combinations include at least one terpolymer of vinyl pyrrolidone, vinyl caprolactam and basic acryl amide monomer and at least one anionic or anionizable polymer with anionic or anionizable groups.

Abstract: The present invention relates to a blend of at least one (meth)acrylate polymer and at least one amorphous propylene-derived polymer, and an optional tackifier that provide pressure sensitive adhesive compositions in which improved peel adhesion to at least one of low and relatively high surface energy substrates can be achieved.

Abstract: The formation of thermoplastic vulcanates may be accomplished with two polymers, wherein one polymer is grafted, or copolymerized with a carboxylic acid anhydride, which acid anhydride grafted polymer then is reacted with an amino silane, which reacts with the acid anhydride and then cross links.

Abstract: Coating composition comprising one or more compounds having functional groups which are reactive to olefinically unsaturated bonds, and a citraconimide functional compound, e.g., benzyl citraconimide, octyl citraconimide, or methoxy propyl citraconimide and/or an itaconimide functional compound as a reactive diluent. The reactive diluents are particularly suitable for use in oxidatively drying coating compositions, such as alkyd based coatings, or coating compositions which are curable by radical copolymerization.

Abstract: The present invention relates to a thermoplastic resin composition comprising a rubber-reinforced thermoplastic resin (A) obtained by graft polymerizing a monomeric mixture (b) comprising an aromatic vinyl compound, a vinyl cyanide compound and optionally other copolymerizable monomeric compound(s) in the presence of a rubber-like polymer (a),

Abstract: The present invention relates to a process of forming a high damping, soft polymer gel. The method involves mixing a polyalkylene grafted poly(alkenyl-co-maleimide) with a poly(alkenyl-co-maleimide) and an extender so as to form a gel.

Abstract: The invention concerns molecular rods, their uses in a method for fixing and/or crystallising macromolecules, the resulting products and uses of said products in the field of materials and structural biology, in particular as biosensors or as biomaterials. Said molecular rods have a structure represented by the general formula (I) and said method essentially consists in incubating, for at least 15 minutes, a biological macromolecule in solution with a molecular rod as defined by the formula, in suitable temperature and pH conditions.

Abstract: The present invention is generally directed to a process for forming a diene-rubber grafted centipede polymer. The process includes copolymerizing a copolymer comprising a maleimide and at least one block chosen from the group consisting of vinyl aromatic hydrocarbons, R1R2ethylenes, or alkyl vinyl ethers with an amine. The amine is further functionalized with at least one functional group capable of grafting to a diene rubber. The copolymer is cocured with a diene rubber to form the diene-rubber grafted centipede polymer.

Abstract: A polymeric gel composition comprising a polymer including an anhydride unit and an alkenyl unit, a crosslinking agent, a maleated polyalkylene, an extender, and an organic fatty acid is provided. The polymeric gel composition has superior high-temperature stability, mechanical strength, and moldability.

Abstract: Synthetic polymers having moieties capable of covalent or hydrogen bonding to cellulose and one or more amphiphilic moieties are disclosed. These polymers are capable of providing two distinct properties to paper products, such as tissues, which properties heretofore have been imparted through the use of at least two different molecules. The backbone of these synthetic polymers is based on modified vinyl polymers, such as polyvinyl alcohol, polyacrylamides and polyacrylic acids.

Abstract: A syndiotactic polystyrene copolymer resin composition with high impact strength, which comprises: (A) about 1-99 weight % of a syndiotactic polystyrene copolymer which is polymerized from at least one macromonomer having an active polymerization group at its end and at least one styrene monomer; and (B) about 99-1 weight % of at least one rubber phase resin and/or at least one thermoplastic resin.

Abstract: A derivatized blend and a process for producing that blend in which a high ethylene content ethylene-propylene polymer and a lower ethylene content ethylene-propylene polymer are subjected to simultaneous blending and shearing to reduce their molecular weights and molecular weight distribution and then reacted with an organic compound to derivatize the blend. The sheared derivatized blend of polymers can function as a shear stable multifunctional viscosity index improver with improved low temperature properties and, in some cases, dispersancy antioxidant and anti-wear properties.

Abstract: A thermoplastic compound comprising at least one linear or branched thermoplastic polymer or copolymer, having at least one reactive or graftable site (F1), which polymer is compounded with at least one hyperbranched dendritic polyester macromolecule being composed of a monomeric or polymeric nucleus and one or more monomeric or polymeric branching or spacing chain extenders. The macromolecule is optionally chain terminated and/or functionalized, whereby terminal chain extender functions, chain termination and/or functionalization provides the macromolecule with at least one reactive or graftable site (F2) being reactive to or graftable onto said reactive or graftable site (F1). In a further aspect, the invention relates to a thermoplastic composition comprising two or more components, whereby at least one is said thermoplastic compound. In yet a further aspect, the invention relates to a thermoplastic article made of one or more thermoplastic compounds, whereby at least one is said thermoplastic compound.

Abstract: The present invention teaches a method for enabling the formation of a high damping, soft polymer gel. The method includes: reacting a poly(alkyl vinylether-co-maleimide) polymer with a maleated polyalkylene and an alkyl diamine under substantially dry conditions sufficient to form a polyalkylene grafted poly(alkyl vinylether-co-maleimide) polymer product; and, dispersing the polyalkylene grafted poly(alkyl vinylether-co-maleimide) polymer product with an extender oil sufficient to form the gel. The present invention also contemplates a polymer gel composition, a polymer composition and an article manufactured from the polymer gel composition.

Abstract: The present invention relates to thermoplastic graft polymer moulding compositions for high-gloss applications, which exhibit a reduced tendency of the additives to exude out of the thermoplastic composition during processing, and which exhibit reduced deposit build-up in the mould.

Abstract: The present invention teaches a method for enabling the formation of a high damping composition. The method includes mixing a centipede polymer, i.e., a poly(disubstituted ethylene-co-maleimide) polymer, and plasticizers or extenders within a non-vulcanized thermoplastic elastomer to form a relatively high damping gel composition.

Abstract: A photosensitive polymer, a dissolution inhibitor, and a chemically amplified photoresist composition containing the photosensitive polymer and the dissolution inhibitor are provided. The photosensitive polymer is a copolymer polymerized with 5-norbornene-2-methanol derivative monomer having a C.sub.1 to C.sub.20 aliphatic hydrocarbon as a side chain, and a maleic anhydride monomer. The dissolution inhibitor is a tricyclodecane derivative or a sarsasapogenin derivative, each having an acid-labile group as a functional group. The chemically amplified photoresist composition containing the photosensitive polymer and/or dissolution inhibitor has a strong resistance to etching and excellent adherence to underlying layer.

Abstract: The present invention provides: a cyclic imino ether group containing polymer with an extremely reduced amount of residual cyclic imino ether group containing monomer; and a production process therefor. The cyclic imino ether group containing polymer is obtained by a process including the step of polymerizing a monomer component including a cyclic imino ether group containing monomer, and contains a cyclic imino ether group containing monomer unit in the ratio of not less than 0.1 mol %, wherein the amount of the cyclic imino ether group containing monomer remaining in the polymer is not more than 15 ppm.

Abstract: A compound comprising a blend of polypropylene with the reaction product of a functionalized polypropylene and polyether amine in which the polyether amine is grafted onto the functionalized polypropylene in a customary mixing apparatus is disclosed. A process for producing the reaction product of the functionalized polypropylene and the polyether amine by melting with polypropylene in a customary mixing apparatus is also disclosed.

Abstract: This invention provides a vulcanizable rubber composition comprising (a) 100 parts by weight of a nitrile-containing highly saturated copolymer rubber obtained by hydrogenating the conjugated diene portions of an unsaturated nitrile-conjugated diene-unsaturated carboxylic acid ester copolymer, (b) 10 to 100 parts by weight of a metallic salt of an .alpha.,.beta.-ethylenically unsaturated carboxylic acid, (c) 0.1 to 30 parts by weight of an organic peroxide vulcanizing agent, and optionally (d) 0.5 to 30 parts by weight of a compound of a group 2A metal in the periodic table. The vulcanized product of this composition is useful as a seal for Freons because it is excellent in low-temperature resistance and resistance to Freon gas permeation and has resistance to the production of cracks in the rubber surface due to the foaming of Freon gas.

Abstract: The present invention relates to a process for producing a thermoplastic resin having high impact strength and good surface gloss, which comprises graft copolymerizing at least a vinyl cyanide compound and at least an aromatic vinyl compound for a short period of less than about 3 hours in the presence of rubber latex having high gel content. The rubber latex can be a mixture of two or more rubber latices having different particle size. The graft copolymer has the characteristics such that the degree of the inner occlusion into the resin is decreased and the degree of surface grafting is increased. Thereby, the resulted thermoplastic resin has a very high impact strength and good surface gloss, and the processability is greatly improved. In addition, when the graft copolymer is polymerized the level of coagulum formation is greatly decreased.

Abstract: A thermoplastic molding composition which features improved impact and flow properties as well as reduced opacity is disclosed. The composition contains(A) 15 to 50 percent of a grafted rubber which contains (a) a crosslinked rubber substrate which contains, as a core, about 1 to 25% relative to its weight of at least one vinylaromatic polymer, and (b) a grafted phase, and(B) 85 to 50 percent of a copolymeric matrix.The composition, which contains no additional grafted rubber components, is also characterized in that (i) the substrate amounts to 60 to 90 percent, and grafted phase amounts to 40 to 10 percent, relative to the weight of the grafted rubber and that (ii) the grafted rubber has a monomodal size distribution and that (iii) the grafted rubber has a weight average particle size of about 0.2 to 1.0 microns.

Abstract: Desirable thermoplastic vulcanizates can be prepared from a polar engineering thermoplastic; a halogenated copolymer of p-alkylstyrene and an isomonoolefin having from 4 to 7 carbon atoms; and either an ethylene rubbery polymer or a diene based rubbery polymer or combinations thereof. The ethylene rubbery polymer desirably has at least one pendant carboxylic acid group, amine group, epoxy group, hydroxyl group or an anhydride of two carboxylic acid groups or combinations thereof. Desirable diene based rubbery polymers include epoxidized natural rubber and epoxidized homopolymers and copolymers of dienes.

Abstract: The present invention teaches a method for enabling the formation of a high damping compound. The method includes: reacting a poly(alkenyl benzene-co-maleimide) polymer with a maleated polyalkylene and an alkyl diamine under substantially dry conditions sufficient to form a polyalkylene grafted poly(alkenyl benzene-co-maleimide) polymer product; and, dispersing the polyalkylene grafted poly(alkenyl benzene-co-maleimide) polymer product within a rubber formulation to form a relatively high damping compound. The present invention also contemplates a rubber compound composition and an article manufactured from the composition.

Abstract: A compound comprising a blend of polypropylene with the reaction of a functionalized polypropylene and polyether amine in which the polyetheramine is grafted into the functionalized polypropylene in a customary mixing apparatus is disclosed. The blend may include an elastomer such as EP rubber and/or a filler such as glass. A process for producing the reaction product of the functionalized polypropylene and the polyether amine by melting with polypropylene in a customary mixing apparatus is also disclosed. Blends of the present invention are advantageously useful to prepare paintable automotive body parts.

Abstract: A thermoplastic polymer composition contains at least two distinct polymers, characterized in that it comprises at least one polymer P1 containing at least one reactive function and at least one modified polyolefin P2 containing at least one succinimide ring substituted on the nitrogen by a reactive group, the ring being carried either by the main chain or by a side chain, and optionally at least one third polymer P3 selected from the group formed by polymers and copolymers obtained by polymerisation of one or more olefinic compounds. A mixture of polymers comprises at least one composition as defined above and at least one other polymer P5 which is identical to or different from polymer P3 and optionally at least one other polymer P6 which is identical to or different from polymer P1.

Abstract: The instant invention teaches a method for enabling the formation of a high damping, soft polymer gel. The method includes: reacting a poly(maleimide-co-alkenyl benzene) polymer with a nylon and an alkyl diamine under substantially dry conditions sufficient to form a nylon grafted poly(maleimide-co-alkenyl benzene) polymer product; and, dispersing the nylon grafted poly(maleimide-co-alkenyl benzene) polymer product with an extender oil sufficient to form the gel. The instant invention also contemplates a polymer gel composition, a polymer composition and an article manufactured from the polymer gel composition.

Abstract: A novel class of interpenetrating polymer networks which are dispersible in conventional coating solvents is disclosed. Such dispersions are useful in preparing protective and/or decorative film coatings and are particularly useful in photosensitive or imaging formulations such as photoresists, solder masks and the like. These polymer networks are comprised of at least two interpenetrating crosslinked polymers. At least one of the polymer networks is formed by polymerization in a solvent. In one embodiment of this invention, at least one polymer network is prepared from macromers to produce a polymer system having functionalized branch or graft linear segments. The solvent dispersible interpenetrating networks of this invention are particularly useful as binders in addition polymerizable photosensitive compositions containing crosslinking monomers such as solder masks. Upon exposure to actinic radiation and suitable thermal curing, solder mask coatings of such photosensitive compositions form multiple, e.g.

Abstract: The present invention provides a thermally resistant resin composition containing PS and PPO, wherein at least one of PS and PPO has an acid group and the acid group is neutralized with a basic metal compound containing a metal element of the group 2B, 3B, 4B or 5B of the periodic table; thermally resistant PS and PPO each with an acid group which is also neutralized in the same manner as described above; and a method for miscible preparation of PS and PPO, wherein at least one of PS and PPO has an acid group and the acid group is neutralized similarly.

Abstract: This invention relates to a resin composition having high impact strength at low temperatures, comprising a polyamide, a graft copolymer obtained by graft polymerizing a monomer mixture of an aromatic vinyl monomer and a vinyl cyanide monomer to a conjugated diene rubber, a copolymer comprising an aromatic vinyl monomer, a vinyl cyanide monomer and other vinyl monomer copolymerizable with the aromatic vinyl monomer and the vinyl cyanide monomer, a modified hydrogenated block copolymer comprising a conjugated diene rubber and styrene or its derivatives to which has been grafted an unsaturated carboxylic acid or an unsaturated carboxylic anhydride, a copolymer comprising an aromatic vinyl monomer, a maleimide monomer, an unsaturated carboxylic acid or an unsaturated carboxylic anhydride, and other vinyl monomer copolymerizable with the aromatic vinyl monomer, and a graft copolymer obtained by graft polymerizing a maleic anhydride to an ethylene-propylene rubber.

Abstract: A thermoplastic resin composition which has low rigidity such as bending strength, bending modulus and tensile strength, high impact resistance, and further low stress and large energy absorption at the time of impact, high heat deformation resistance and excellent moldability and comprises 5 to 65 by weight of the copolymer (I) having Tg (glass transition temperature) of not more than 20.degree. C., 20 to 80 parts by weight of the maleimide copolymer (II) and 15 to 75 part by weight of the graft copolymer (III) having a graft ratio of 10 to 70% so that the total amount of the copolymers (I), (II) and (III) becomes 100 parts by weight, can be obtained.

Abstract: Plastic compositions, containers useful in the storage of red blood cells, and methods for providing such red blood cell storage containers and for storing red blood cells are disclosed. The plastic composition includes a polyolefin copolymer and a plasticizer. The flexibility of such plastic compositions and containers made thereof is substantially unchanged upon heating to a high temperature relative to its flexibility before such heating.

Abstract: Disclosed is a propylene polymer composition comprising (a) a propylene polymer, (b) an olefin type elastomer and (c) a polar group-containing olefin polymer composition obtained by heating (c-1) an olefin polymer containing a carboxyl group or an acid anhydrous group in its molecule and (c-2) an amino compound, each in a specific amount. Also disclosed is a propylene polymer composition comprising (a) a propylene polymer, (b) an olefin type elastomer, (c-1) an olefin polymer containing a carboxyl group or an acid anhydrous group in its molecule and (c-2) an amino compound, each in a specific amount. The propylene polymer compositions of the present invention are excellent in properties of being coated with various coatings.

Abstract: A compound comprising a blend of polypropylene with the reaction product of a functionalized polypropylene and polyether amine in which the polyether amine is grafted onto the functionalized polypropylene in a customary mixing apparatus is disclosed. A process for producing the reaction product of the functionalized polypropylene and the polyether amine by melting with polypropylene in a customary mixing apparatus is also disclosed.

Abstract: A thermoplastic molding composition containing a blend of polycarbonate, vinyl copolymer, such as SAN, and a graft polymer, such as ABS is disclosed. The invention resides in the finding that the incorporation of a compatibilizing agent which comprises a polymeric resin having a number average molecular weight of at least about 21,000 and which is miscible with the grafted phase of the graft polymer and which contains secondary amine reactive groups in its structure yields stable compositions having improved mechanical properties especially at low temperatures.

Abstract: Graft copolymers are obtainable by reactingA) polyarylene ethers,B) polyamides andC) copolymers which contain cyclic, .alpha.,.beta.-unsaturated dicarboxylic anhydridesand are used for the preparation of thermoplastic molding materials or as compatibilizers for polymer blends based on polyarylene ethers and polyamides.

Abstract: Thermoplastic moulding compositions containingI) At least one graft polymer which is obtainable by emulsion polymerisation of for example styrene and acrylonitrile under special conditions,II) At least one graft polymer that can be obtained by solution, bulk or suspension polymerisation of for example styrene and acrylonitrile in the presence of a rubber,III) At least one rubber-free copolymer of for example styrene and acrylonitrile,and their use for producing mouldings.

Abstract: Thermoplastic moulding compositions of the ABS type, containingI) at least one graft polymer, obtainable by emulsion polymerisation of resin-forming monomers in the presence of a mixture comprising a butadiene polymer latex (A) having a particle diameter d.sub.50 of .ltoreq.320 nm, a particle diameter distribution of 30 to 100 nm in width and a gel content of .ltoreq.70 wt. % and a butadiene polymer latex (B) having a particle diameter d.sub.50 of .gtoreq.370 nm, a particle diameter distribution of 50 to 500 nm in width and a gel content of .gtoreq.270 wt. %,II) at least one graft polymer, obtainable by emulsion polymerisation of resin-forming monomers in the presence of a butadiene polymer latex (C) having a particle diameter d.sub.50 of from 110 to 150 nm, a particle diameter distribution of 20 to 50 nm in width and a gel content of from 80 to 98 wt. %, andIII) at least one rubber-free copolymer composed of resin-forming monomersand the use of the moulding compositions for the production of mouldings.

Abstract: A blend and a process for producing that blend in which a high ethylene content ethylene-propylene polymer and a lower ethylene content ethylene-propylene polymer are subjected to simultaneous blending and shearing to reduce their molecular weights and molecular weight distribution. The sheared blend of polymers can function as a shear stable dispersant viscosity index improver with improved lower temperature properties or the hydrocarbon base for multifunctional for viscosity index improvers, motor fuel additives or polymeric dispersants.

Abstract: This invention relates to impact-resistant thermoplastic moulding compositions based on a graft rubber, a thermoplastic resin and a small quantity of a free acid-functional nitrile rubber.

Abstract: A glass fiber-reinforced thermoplastic resin excellent in providing a balance between processability, tapping strength and heat resistance. The composition comprising (A) 10 to 60% by weight of a terpolymer which comprises N-phenylmaleimide, styrene and acrylonitrile, (B) 5 to 20% by weight of a graft polymer which comprises at least one rubber selected from the group consisting of a conjugated diene rubber, an ethylene-propylene rubber and an ethylene-butylene rubber comprising ethylene and butylene, to which rubber styrene and acrylonitrile are graft polymerized, (C) 10 to 80% by weight of a copolymer which comprises styrene and acrylonitrile, and (D) 5 to 35% by weight of glass fiber, wherein(a) the terpolymer has an intrinsic viscosity of 0.20 dl/g to 0.70 dl/g, (b) the copolymer has an intrinsic viscosity of 0.40 dl/g to 1.

Abstract: A method for the removal, separation, and concentration of cesium cations from a source solution which may contain larger concentrations of other alkali metal ions comprises bringing the source solution into contact with a polymeric resin containing poly(hydroxyarylene) ligands. The poly(hydroxyarylene) ligand portion(s) of the polymeric resins has affinity for cesium, thereby removing cesium from the source solution. The source solutions from which the cesium has been removed may then be treated or disposed of as desired and the cesium cations are then removed from the polymeric resin through contact with a much smaller volume of a receiving solution in which these cesium cations are soluble and has greater affinity for such cations than does the poly(hydroxyarylene) ligand or protonates the ligand, thereby quantitatively stripping the completed cesium cations from the ligand and recovering them in concentrated form in said receiving solution.

Abstract: The present invention relates to bonding resins having excellent adhesion to polar polymers, particularly ionomers, acid copolymers and ethylene vinyl alcohol copolymer. These resins preferably contain: 1) an ethylene polymer or copolymer (ungrafted, grafted or partially grafted); 2) a grafted elastomer; and 3) optionally, an ethylene alpha olefin copolymer which is wholly or partially grafted. Preferred grafting comonomers include maleic anhydride and derivatives thereof.

Abstract: Thermoplastic moulding compositions of the ABS type ofI) at least one graft copolymer which is obtainable by emulsion polymerization of styrene and acrylonitrile in the weight ratio 90:10 to 50:50, wherein styrene and/or acrylonitrile can be completely or partly replaced by .alpha.-methylstyrene, methyl methacrylate or N-phenylmaleimide, in the presence of at least two butadiene polymer latices of types (A) and (B), which each contain, copolymerized, 0 to 50 wt. % of a further vinyl monomer, and wherein the weight ratio of monomers used to butadiene polymers used is 25:75 to 70:30, andII) at least one copolymer of styrene and acrylonitrile in the weight ratio 90:10 to 50:50, wherein styrene and/or acrylonitrile can be completely or partly replaced by .alpha.-methylstyrene, methyl methacrylate or N-phenylmaleimide, characterized in that the butadiene polymer latex (A) has a particle diameter d.sub.50 .ltoreq.320 nm, a width of the particle size distribution (measured as d.sub.90 -d.sub.

Abstract: A heat-resistant high-nitrile polymer composition obtained by the graft copolymerization of 100 parts by weight of a monomer mixture comprising 50 to 80% by weight of an unsaturated nitrile monomer, a maleimide monomer, an aromatic vinyl monomer, and a monomer copolymerizable with the foregoing monomers, in the presence of 1 to 40 parts by weight of a conjugated diene-based synthetic rubber containing not less than 50% by weight of a conjugated diene monomer unit, wherein the concentration of residual maleimide monomer in the polymer composition is not greater than 200 ppm by weight. This polymer composition is suitable for use as a molding material for extrusion molding, blow molding, injection molding and the like, and is useful in applications which require gas barrier properties, chemical resistance, non-adsorptive properties and the like, and which require use in automobiles, heat resistance sufficient for heat filling, and safety and hygienic properties.

Abstract: ABS type thermoplastic moulding compounds obtainable byA) producing a rubber latex with an average particle diameter d.sub.50 of 30 to 160 nm and a gel content of 75 to 100 wt. %B) emulsion polymerization of an amount of butadiene and optionally up to 50 wt. % (with reference to the total amount of monomer in stage B) of a comonomer in the presence of the rubber obtained in stage A, such that a rubber latex (B) with an average particle diameter d.sub.50 =220 to 330 nm and a gel content of 25 to 70 wt. % is produced,C) emulsion polymerization of 40 to 95 parts by wt. of a mixture of styrene and acrylonitrile, which optionally contains up to 50 wt. % (with reference to the total amount of monomers used in stage C) of one or more comonomers, in the presence of 5 to 60 parts by wt. (with reference to the solids) of the rubber obtained in stage B by introducing the monomer in such a way that 55 to 90 wt.

Abstract: Thermoplastics built up from N-(2-ethyl-6-methyl)phenylmaleimide and styrene, it being possible for all or some of the styrene to be replaced by at least one other monomer component.

Abstract: Copolymers containing carboxyl groups in aqueous dispersion form or redispersible powder form and their water-soluble salts, based on ethylenically unsaturated and copolymerizable monomers, the macro-molecules of which contain at least 24% by weight of monomer units carrying carboxyl groups prepared, by emulsion copolymerization initiated by free radicals in the presence of polyvinyl alcohol (PVA) or polyvinylpyrrolidone (PVP) dissolved in the aqueous phase and isolation of the copolymers in aqueous dispersion form, and optionally subsequent removal of water by spray drying to obtain redispersible copolymer powders and processes for their preparation and their use as thickeners in aqueous formulations which copolymers, by conversion into their water-soluble salt forms, are useful as thickening agents having a surprisingly advantageous rheology-modifying action in aqueous systems.