Abstract: The present invention provides a dispersion stabilizer for suspension polymerization that, when used for suspension polymerization of a vinyl compound, provides excellent polymerization stability, and can produce a vinyl polymer having a reduced number of coarse particles, and a reduced number of fisheyes when molded into a sheet form. The present invention also provides a method therewith. The present invention relates to a dispersion stabilizer for suspension polymerization of a vinyl compound, the dispersion stabilizer comprising a vinyl alcohol polymer (A) having a viscosity-average degree of polymerization of more than 400 and less than 1,000, a degree of saponification of more than 67 mol % and less than 78 mol %, 0.02 mol % to 1.0 mol % of a group having an ethylenic double bond in its side chain, and an absorbance (x) at 280 nm of more than 0.17 and less than 0.65 in an ultraviolet absorption spectrum of a 0.1 mass % aqueous solution.

Abstract: A three-dimensional cell growth medium is described. The cell growth medium may comprise hydrogel particles swollen with a liquid cell growth medium to form a granular gel yield stress material which undergoes a phase transformation from a solid phase to a liquid-like phase when an applied stress exceeds the yield stress. Cells may be placed in the three-dimensional cell growth medium according to any shape or geometry, and may remain in place within the three-dimensional cell growth medium.

Abstract: The present invention provides a vinyl alcohol-vinyl acetate copolymer having excellent solubility and capable of providing a film having high flexibility, high mechanical strength, and high adhesion, and a method for producing a vinyl alcohol-vinyl acetate copolymer. Provided is a vinyl alcohol-vinyl acetate copolymer including a unit of vinyl alcohol and a unit of vinyl acetate, the vinyl alcohol-vinyl acetate copolymer having a triad unit chain ratio TOO of 7.5 or less, where the triad unit chain ratio TOO is obtained using the following formula (1): [ Math .

Abstract: Water-redispersible polymer powders with improved characteristics in building materials are prepared using a drying aid which is a polyvinyl alcohol copolymer also containing vinyl ester monomers and specific comonomers.

Abstract: The present invention relates to a method comprising the steps of a) contacting under emulsion polymerization conditions vinyl acetate; a cyclic ketene acetal monomer; and a monoethylenically unsaturated acid monomer or a salt thereof; to form an aqueous dispersion of copolymer particles comprising structural units of vinyl acetate, the cyclic ketene acetal, and the monoethylenically unsaturated acid monomer or a salt thereof; wherein the cyclic ketene acetal monomer is characterized by following structure: where n and the R groups are as defined herein. The method of the present invention provides a water-borne dispersion that is substantially free of volatile organic solvents and that provides a readily degradable polymer that is useful, for example, in the manufacture of biodegradable packaging products.

Abstract: Subjects of the invention are processes for preparing vinyl acetate-ethylene copolymers in the form of their aqueous dispersions or water-redispersible powders by means of radically initiated emulsion polymerization and optional subsequent drying of the resultant polymer dispersions, characterized in that the emulsion polymerization of vinyl acetate, ethylene and optionally one or more further ethylenically unsaturated monomers is carried out in the presence of one or more protective colloids in one or more Taylor reactors.

Abstract: The invention relates to a polyisocyanate mixture containing at least one polyisocyanate based on 1,5-diisocyanatopentane and at least one organic solvent, said organic solvent being inert with respect to isocyanate groups and the polyisocyanate mixture has a solid body content of ?35 and ?65 wt. %. The invention also relates to a two-component system, to a method for producing a coating, to the thus obtained coatings and to a composite consisting of the coating and a substrate.

Abstract: The invention relates to a method for manufacturing macroscopic fibers of titanium dioxide (TiO2) by continuous extrusion in a one-way flow, to the macroscopic fibers of TiO2 that can be obtained by such a method, to the use of said fibers in heterogeneous photocatalysis for decontamination of organic pollutants from gaseous environments, and to a method for decontaminating gaseous environments, in particular air, using such fibers.

Abstract: The present invention relates to a composition comprising (?) at least one inorganic binder and (?) at least one water-soluble copolymer based on (a) 0.1 to 20 wt % of at least one monomer of the formula (I) and (b) 25 to 99.9 wt % of at least one hydrophilic monomer (b) which is different from monomer (a), where the at least one copolymer has a molar mass average M of 1 500 000 to 30 000 000 g/mol. Furthermore, a process for producing this composition is disclosed. A further aspect of the present invention is the use of the copolymer of component (?) as rheological additive in a composition of the invention.

Abstract: Disclosed are aqueous carpet-coating compositions suitable for use as binders or adhesives in carpet products. Such compositions, prior to being applied to carpet substrates and cured, comprise: A) a selected type of vinyl acetate/ethylene (VAE) copolymer dispersion which has been stabilized with emulsifiers and a cellulose ether-based protective colloid, and B) at least one carbon black based filler in the form of a dispersion/slurry with a solids content between 20 and 70%. These coating compositions exhibit especially desirable initial viscosity and viscosity stability characteristics. Carpet products which utilize such coating compositions to provide binder and/or adhesive layer within the carpet are also disclosed. Such carpet products can have desirable odor-controlling and odor-absorbing properties.

Abstract: A coating composition comprises an emulsion copolymer of a monomer mixture comprising at least one vinyl ester, ethylene, and a stabilizing system. The stabilizing system comprises at least one polyvinyl alcohol. The monomer mixture comprises from 60 to 82 wt % of the at least one vinyl ester and from 18 to 40 wt % of the ethylene based on the total weight of monomers in the mixture. The stabilizing system comprises from 1 to 5 wt % of at least one medium molecular weight polyvinyl alcohol and at least one low molecular weight polyvinyl alcohol. The emulsion copolymer has a solids content from 50% to 60% and a viscosity ranges from 500 to 6,000 mPa·s. and a formaldehyde content of less than 10 ppm as determined by HPLC.

Abstract: Waterborne coatings are described having an acceptable balance of properties both during the storage of coating, application and drying. The period in which irregularities in a freshly applied coating can be repaired without resulting in brush marks is referred to as the open time. Aqueous coatings generally employ dispersed high molecular weight polymers as binders. These binders often provide short open times when the coating is dried since the dispersed polymer particles tend to be immobilized quickly in the edge region of an applied coating. As a result, the viscosity of the coating increases rapidly, which leads to a limited window of workability. The instant invention provides additives that are not volatile but that will extend the time that the film is malleable after it is applied without interfering with other attributes, such as the resistance of the coating to freezing while in the can prior to application.

Abstract: Disclosed are low-formaldehyde aqueous dispersions of vinyl ester/ethylene, e.g., vinyl acetate/ethylene (VAE), copolymers suitable for use in adhesives for applications such as tobacco or food products wherein only very low levels of formaldehyde are permitted. Such dispersions are prepared by emulsion copolymerization of a monomer mixture comprising a vinyl ester, ethylene, a stabilizing system comprising polyvinyl alcohol preferably having a degree of hydrolysis of at least 97 mole %, and a selected type of free radical redox polymerization initiator system. This selected redox initiator system comprises both a water-insoluble oxidizing agent and a sulfuric acid-based reducing agent. The monomer mixture which is polymerized is substantially free of co-monomers which yield free formaldehyde upon drying or curing of the dispersion and is also substantially free of ethylene oxide-containing emulsifiers.

Abstract: A depilatory composition, and a method of using a depilatory composition, where the present invention is a depilatory composition comprising: (1) a film-forming polymer; (2) depilatory active ingredients; and (3) a solvent system, wherein the depilation composition forms a peelable film after drying. The depilation composition of the present invention uses a blend of fully and partially hydrolyzed poly(vinyl alcohol).

Abstract: An aqueous dispersion of a vinyl ester/ethylene copolymer is prepared by emulsion copolymerization of a monomer mixture comprising a vinyl ester, ethylene and a polyvinyl alcohol stabilizing system consisting essentially of (a) about 0.5 to about 3 wt. % based on the total monomer weight of a first polyvinyl alcohol having a degree of hydrolysis of at least 98 mole % and (b) about 1 to about 4 wt. % based on the total monomer weight of a second polyvinyl alcohol having a degree of hydrolysis of about 85 to about 90 mole % and a weight average molecular weight of at least 85,000 g/mol.

Abstract: What are described are polyvinyl ester dispersions which are prepared in a multistage process and have a low content of polymerized acids or acid anhydrides. They can be obtained by a multistage process in which a polyvinyl ester dispersion is obtained in a first stage, monomers in dissolved or pure form are added to the reaction mixture in a second stage and then the polymerization is started again. The polymer dispersions obtained in this way are notable for a low coagulum content and for increased tensile strengths of the films formed therefrom.

Abstract: The synthesis of high performance polyvinyl ether (PVE) fluids using a Lewis acid based cationic polymerization process is disclosed. The polyvinyl ether fluid have repeating vinyl ether units of the general formula —[CH2—CH(O—R)]n, wherein R is comprised of a branched or linear alkyl group having at least 4 carbon atoms and n is a whole number representing the average number of repeating units in the polyvinyl ether. The resulting PVE fluids exhibit excellent lubricant properties, similar to poly-alpha olefins (PAOs), but the PVE fluids have the benefit of higher polarity than PAOs and thus have better solubility and dispersity of polar additives.

Abstract: A description is given of an aqueous vinyl ester copolymer dispersion stabilized with a combination of at least one protective colloid and of at least one emulsifier, said dispersion having a viscosity of less than 8000 mPa*s, a weight average dw of the particle sizes of 0.5 to 10 ?m, and a ratio of weight average to number average of the particle sizes, dw/dn, of at least 2.5, and the polymer possessing a glass transition temperature of between ?30 and +15° C. The dispersion can be used as an adhesive for nozzle application processes.

Abstract: The present invention relates to a novel resin composition useful as a coating agent or a binder for medicines, drugs for animals, agricultural chemicals, fertilizers, foods or the like, which contains a polyvinyl alcohol copolymer as a main component. More particularly, the present invention relates to a resin composition, characterized in that the composition is obtained by copolymerizing a polyvinyl alcohol having an average polymerization degree of 1300 or less, and at least one polymerizable vinyl monomer in a weight ratio of 6:4 to 9:1.

Abstract: The present invention relates to a method for producing a porous resin particle containing an aromatic vinyl compound-aromatic divinyl compound copolymer having a hydroxyl group, the method including: dissolving a monomer mixture containing an aromatic vinyl compound, an aromatic divinyl compound and a (meth)acrylic acid ester having one hydroxyl group within the molecule thereof, and a polymerization initiator in an organic solvent to obtain a solution containing the monomer mixture and the polymerization initiator; suspending the solution in water in the presence of a dispersion stabilizer; and performing a suspension copolymerization. The method of the invention is capable of easily producing a porous resin particle containing an aromatic vinyl compound-aromatic divinyl compound copolymer having a hydroxyl group, that is used as a support for solid phase synthesis and enables efficient nucleic acid synthesis.

Abstract: Redispersible polymer powders which are cationically stabilized by spray drying a polymer dispersion with a cationic polymer can be used in higher concentrations in chemical building construction materials without introducing adverse properties.

Abstract: The aforementioned problems can be solved by a dispersion stabilizer composed of a polyvinyl alcohol polymer (B) having a double bond in its side chain. The polyvinyl alcohol polymer (B) is obtained by esterifying a polyvinyl alcohol polymer (A) with a carboxylic acid having an unsaturated double bond or a salt thereof. Furthermore, the aforementioned problems can be solved with a dispersion stabilizer composed of a carboxylic acid-modified polyvinyl alcohol polymer (C) that is obtained by esterifying a polyvinyl alcohol polymer (A) with aliphatic carboxylic acid and/or aromatic carboxylic acid containing no olefinically unsaturated bond in the molecule or a salt thereof.

Abstract: An object of the present invention is to provide a method for producing a block copolymer solid in which microphase-separated structures are formed with good productivity. The present invention provides a method for producing a block copolymer solid in which a microphase-separated structure is formed, or an alloy, blend or composite solid containing a block copolymer in which a microphase-separated structure is formed, which comprises the following steps (1) to (3): (1) immersing a block copolymer solid or an alloy, blend or composite solid containing a block copolymer in a solvent in which each component is insoluble; (2) putting the solid obtained in (1) above in a pressure-resistant container; and (3) irradiating the solid or the solvent in (2) above with microwave.

Abstract: The present invention relates to a novel resin composition useful as a coating agent or a binder for medicines, drugs for animals, agricultural chemicals, fertilizers, foods or the like, which contains a polyvinyl alcohol copolymer as a main component. More particularly, the present invention relates to a resin composition, characterized in that the composition is obtained by copolymerizing a polyvinyl alcohol having an average polymerization degree of 1300 or less, and at least one polymerizable vinyl monomer in a weight ratio of 6:4 to 9:1.

Abstract: Spherical particles having a mean diameter in the range from 1 to 20 ?m, comprising (a) from 85 to 99% by weight of a crosslinked random copolymer having a glass transition temperature Tg in the range from ?75 to ?40° C. (b) and from 1 to 15% by weight of at least one organic substance selected from waxes, protective colloids and plasticizers.

Abstract: The present invention relates to a novel resin composition useful as a coating agent or a binder for medicines, drugs for animals, agricultural chemicals, fertilizers, foods or the like, which contains a polyvinyl alcohol copolymer as a main component. More particularly, the present invention relates to a resin composition, characterized in that the composition is obtained by copolymerizing a polyvinyl alcohol having an average polymerization degree of 1300 or less, and at least one polymerizable vinyl monomer in a weight ratio of 6:4 to 9:1.

Abstract: A method for preparing polyvinyl alcohol and polyvinyl acetate latex by use of a kettle bottom residue from vinyl acetate production process includes: distilling a kettle bottom residue of vinyl acetate to obtain a crude acetic acid and a distillation residue; multiple washing the distillation residue with water under boiling condition to obtain a washing residue containing polyvinyl acetate; dissolving a first portion of the washing residue into a first solvent to obtain a first polyvinyl acetate solution; subjecting the first polyvinyl acetate solution to saponification with an alkali aqueous solution; dissolving a second portion of the washing residue into a second solvent; and dispersing the second polyvinyl acetate solution into the polyvinyl alcohol solution, and optionally recovering the solvent to obtain a polyvinyl acetate latex; or adding the second polyvinyl acetate solution into an emulsion reaction system and optionally recovering vinyl acetate, to obtain a polyvinyl acetate latex.

Abstract: Protective-colloid-stabilized polymers in the form of their aqueous dispersions or of their water-redispersible powders are based on homo- or copolymers of one or more monomers from the group consisting of vinyl esters of optionally branched alkyl carboxylic acids having from 1 to 15 carbon atoms, (meth)acrylic esters of alcohols having from 1 to 15 carbon atoms, vinylaromatics, olefins, dienes, and vinyl halides, wherein partially hydrolyzed vinyl acetate-ethylene copolymers with an ethylene content of from 1 to 15 mol %, a degree of hydrolysis DH of the vinyl acetate units of 80 mol %<DH<95 mol %, and a Höppler viscosity in 4% by weight aqueous solution of from 2 to 30 mPas, are present as protective colloids.

Abstract: The present invention is directed to a cationic polymer emulsion binder that may be combined with a cationic active ingredient and used as a non-woven binder. This combination of cationic binder and cationic active ingredient may occur as a mixture of a cationic binder and at least one cationic active ingredient, which is then applied to loose fibers to form a non-woven; or the combination may occur after a non-woven is formed using a cationic binder, and said non-woven is then contacted with a cationic active ingredient. Non-woven wipes of the invention retain far less cationic active ingredients during use, resulting in less waste and less use of the active ingredients for the same effect as wipes made with anionic or non-ionic binders.

Abstract: The invention is to provide: an aqueous emulsion which is excellent in emulsion polymerization stability when produced, and is excellent in mechanical stability, freezing stability, stability to long-term standing at high temperatures, water resistance adhesive property, and redispersibility; and a redispersible resin and adhesive where the aqueous emulsion is used. The invention relates to an aqueous emulsion comprising a polyvinyl alcohol-based resin (A) comprising a 1,2-diol component in a side chain and having an average degree of polymerization of 50 to 2,500 and a polymer (B) comprising at least one unsaturated monomer selected from an ethylenically unsaturated monomer and a diene-based monomer.

Abstract: An aqueous composition adhesive composition comprising a vinyl acetate polymer and a plasticizer having the general formula: wherein R1 and R2 are independently selected from the group consisting of saturated straight or branched and unsubstituted alkyl or cycloalkyl groups having from 4 to 8 carbon atoms.

Abstract: A process for preparing polymer dispersions stabilized by polyvinyl alcohol includes a step of emulsion polymerization. The polymerization occurs such that at least 60% of the total conversion occurs at a temperature from 100° C. to 140° C.

Abstract: Provided is a (meth)acrylic resin emulsion comprising, as a dispersant, a vinyl alcohol polymer having a degree of saponification of from 80 to 95 mol % and a degree of polymerization of from 400 to 2000 and, as a dispersoid, a polymer comprising at least one type of monomer units selected from acrylate monomer units and methacrylate monomer units, which has a “factor a” of at least 0.3 that indicates the particle size distribution width of the emulsion and of which the film formed at 20° C. to have a thickness of 500 ?m has a tensile strength of at least 100 kg/cm2. The emulsion is excellent in all its film strength, film transparency and mechanical stability and further in its alkali resistance.

Abstract: Multistage polymers predominantly stabilized by nonionic emulsifiers and derived from hard and soft monomer compositions containing vinyl esters, of which at least one monomer composition must contain an unsaturated compromisable organosilicon compound, are described. The plastic dispersions can be used as binders in emulsion paints and finishes and impart to these excellent scrub resistance in addition to good blocking resistance.

Abstract: The invention provides a process for powdering highly unsaturated fatty acid esters of ascorbic acid which are pasty and problematic in physical properties by a simple and easy means; highly unsaturated fatty acid esters of ascorbic acid which are improved in stability by powdering; and compositions containing the powdered highly unsaturated fatty acid esters of ascorbic acid. Specifically, a process for powdering a highly unsaturated fatty acid ester of ascorbic acid as represented by the general formula (I): RCO-A [wherein RCO— is acyl derived from a highly unsaturated fatty acid; and A is an ascorbic acid residue bonded through an —O— linkage resulting from an hydroxyl group of ascorbic acid], characterized by mixing a highly unsaturated fatty acid ester of ascorbic acid as represented by the general formula (I) with an aqueous solution of a water-soluble filler to form an emulsion and dehydrating and drying the emulsion by a spray drying method.

Abstract: Disclosed is a synthetic resin emulsion powder obtained by spray-drying a composition that comprises an emulsion (A) where the dispersoid is a polymer that having one or more unsaturated monomer units selected from ethylenic unsaturated monomers and dienic monomers, and a polyvinyl alcohol (B) having, in the molecule, from 1 to 12 mol % of ethylene units. The emulsion powder has good redispersibility and good water resistance. Its redispersion well form good films and has good storage stability at low temperatures. The emulsion powder is favorable for additives to hydraulic substances, as it well disperses in hydraulic substances such as cement mortar and gives hardened articles of high mechanical strength. The emulsion powder is also favorable for joint materials for hydraulic substances, as its adhesiveness and durability are both good and gives jointed articles of high mechanical strength.

Abstract: A filler-containing an organic polymer dispersion is provided. The organic polymer of the dispersion is polymerized in the presence of particles of at least one filler. The ratio of the particle size of the filler particles to the particle size of the polymer particles is in the range of from 1.1:1 to 20:1.

Abstract: A surfactant composition has good emulsifiability for monomer(s), and can provide a polymer emulsion (herein after simply called “the emulsion”) of good stability while decreasing coagulations of polymer particles in the emulsion. The surfactant composition contains the following components (A) and (B): (A) a reactive surfactant containing at least one polymerizable double-bond group and at least one ionic group in a molecule, and (B) a nitrogen compound insoluble or slightly soluble in ethanol. A weight ratio (A:B) of the component (A) to the component (B) is from 100:0.03 to 100:1.0.

Abstract: Aqueous polymer dispersions which are obtainable by emulsion polymerization of ethylenically unsaturated monomers in an aqueous medium in the presence of free radical polymerization initiators and stabilizers, amphiphilic polymers which comprise one or more hydrophobic units (A) and one or more hydrophilic units (B) being used as the stabilizer before, during or after the polymerization, and the hydrophobic units (A) being formed from a polyisobutene block, at least 50 mol % of whose polyisobutene macromolecules have terminally arranged doubled bonds, processes for the preparation of the aqueous polymer dispersions by polymerizing ethylenically unsaturated monomers in the presence of free radical initiators and said amphiphilic polymers, which are used before, during or after the polymerization, and the use of the resulting aqueous polymer dispersions as associative thickeners in paper coating slips, in textile production, as thickeners for textile print pastes, in the pharmaceutical and cosmetics sector, for

Abstract: An elastomeric composition includes a reaction product of an isocyanate component and a resin component comprising a polyol and a polyetheramine in the presence of a first catalyst comprising a metal and a second catalyst comprising an amine. An elastomeric system and a method of making an elastomer are provided. The method includes providing the isocyanate component and the resin component, combining the resin component and the isocyanate component in the presence of the first and second catalysts to form an elastomeric composition, applying the elastomeric composition to a mold having a mold cavity, curing the elastomeric composition to form the elastomer, and demolding the elastomer from the mold cavity. An article including a first layer formed from the elastomeric composition emits less than 100 ?g/g of volatile organic compounds over 0.5 hour at 90° C.

Abstract: Various processes and methods are disclosed for incorporating polyvinyl alcohol additives into products. In one embodiment, polyvinyl alcohol particles are dissolved in a solvent without the use of external heat to form a polyvinyl alcohol solution for incorporation into a product. In an alternative embodiment, polyvinyl alcohol particles are directly incorporated into a starch-based adhesive composition. Through the processes of the present disclosure, solid polyvinyl alcohol particles can be delivered directly to a manufacturing facility where the product that incorporates the polyvinyl alcohol additive is being made or formulated. In this manner, since the polyvinyl alcohol particles are not predissolved, the costs associated with shipping and transporting the polyvinyl alcohol product are greatly reduced.

Abstract: The present invention provides a black ink composition comprising (1) water, (2) carbon black, and (3) a fine particle emulsion, wherein (A) the content of said carbon black is less than 0.4 wt %, and wherein (B) the solid content of said fine particle emulsion is 20 times or more the content of said carbon black. Also disclosed are an ink set comprising the black ink composition, a recording method using the ink set, and recorded matter obtained by the method.

Abstract: The invention provides a process for preparing polymeric beads of complexing resin incorporating magnetic particles, which process comprises: producing a dispersion having a continuous aqueous phase and a dispersed organic phase, said organic phase comprising one or more polymerisable monomers, magnetic particles and a dispersing agent for dispersing said magnetic particles in the organic phase; polymerising said one or more polymerisable monomers to form polymeric beads incorporating said magnetic particles, wherein said polymeric beads include amine groups capable of complexing a transition metal cation, or wherein said polymeric beads are reacted with one or more compounds to provide amine groups capable of complexing a transition metal cation, complexing resins prepared by this process, and polymeric beads of complexing resin comprising a polymer matrix having magnetic particles dispersed substantially uniformly therein, wherein the polymer matrix incorporates amine groups capable of complexing a transiti

Abstract: The present invention relates to hyperbranched copolymers and compositions in which they are incorporated, e.g., colorant compositions, tint bases, and coatings such as latex paint, and methods for making such copolymers and compositions.

Abstract: The present invention provides an aqueous emulsion having excellent polymerization stability and standing stability and a redispersible powder. Specifically, the present invention relates to an aqueous emulsion of a polymer obtained by polymerizing an acrylic monomer in the presence of a polyvinyl alcohol containing an acetoacetic ester group; wherein the polyvinyl alcohol containing an acetoacetic ester group has block character [?] of 0.3 to 0.6, hydrolysis degree of at least 97% by mol and acetoacetic esterification degree of 0.01 to 1.5% by mol, and the value obtained by dividing the maximum value by the minimum value of the respective average acetoacetic esterification degree for each of the polyvinyl alcohol containing an acetoacetic ester group separated by particle size of 44 to 74, 74 to 105, 105 to 177, 177 to 297, 297 to 500 and 500 to 1680 ?m is 1.0 to 3.0. Also, the present invention relates to a redispersible fiber obtained by drying the aqueous emulsion.

Abstract: A polychloroprene latex is provided with excellent adhesive strength, particularly for an EVA material, by dissolving an ethylene/vinyl acetate copolymer in a chloroprene monomer alone or in a mixture of a chloroprene monomer and a monomer copolymerizable with chloroprene to prepare a monomer solution, which is emulsified and dispersed in an aqueous solution containing an emulsifier and/or a dispersant, followed by polymerization to produce a polychloroprene latex. The obtained polychloroprene latex can provide improved adhesive strength particularly for an EVA material.

Abstract: A resin composite having excellent tensile strength and a process for producing the composite are provided. The resin composite comprises a resin and aluminum hydroxide having an average primary-particle diameter of about 100 nm or smaller and has an index Y/X of 0.1 or less provided that the value X is an average intensity of intensities of aluminum characteristic X-ray measured by scanning a beam on a straight line on the composite with an electron-probe X-ray microanalyzer and the value Y is a standard deviation of the intensities.

Abstract: The invention relates to aqueous polymer dispersions, obtained by the emulsion polymerisation of ethylenically unsaturated monomers in an aqueous medium in the presence of polymerisation initiators and stabilisers that form radicals. According to the invention, amphiphilic polymers are used as stabilisers prior to, during or after polymerisation, said polymers containing one or more hydrophobic units (A) and one or more hydrophilic units (B), the hydrophobic units (A) being formed from a polyisobutene block, wherein at least 50 mol % of the polyisobutene macro-molecules have terminal double bonds. The invention also relates to a method for producing the aqueous polymer dispersions by the polymerisation of ethylenically unsaturated monomers in the presence of initiators that form radicals and the aforementioned amphiphilic polymers, which are used prior to, during or after polymerisation.

Abstract: A description is given of a process for preparing bimodal or multimodal polymers from olefinically unsaturated monomers in an aqueous medium. The process features the introduction as initial charge of selected mixtures of polymeric stabilizers and of at least one selected ionic comonomer. In the polymerization process the monomer is metered continuously or discontinuously into the said initial charge. In this way it is possible by means of simple process measures to prepare bimodal or multimodal dispersions.

Abstract: The invention relates to methods for manufacturing a water-in-water polymer dispersion containing polymer A and at least one polymer dispersant B, according to which monomers, which are dispersed in an aqueous phase containing water-soluble dispersant B, are subjected to radical polymerization, possibly following the addition of a water-soluble salt, and, after polymerisation, a water-soluble acid is added to the water-soluble and/or water-swellable polymer A obtained in this way, where the acid is added in quantities of 0.1 to 5% by weight and the salt in quantities of up to a maximum of 3% by weight, each referred to the total dispersion, and the total quantity of salt and acid amounts to a maximum of 5% by weight, referred to the total dispersion.