Abstract: A process for preparing an emulsion polymer comprising placing a first mixture of monomers in a feed tank B which is connected directly to a reactor, placing a second mixture of monomers in a feed tank A which is connected to the feed tank B, and continuously varying the composition ratio of the monomers of feed tanks A and B in the emulsion polymer. The composition ratio is varied by varying the rate of feeding of the second mixture of monomers present in tank A into tank B while simultaneously varying the rate of feeding of the first mixture of monomers present in tank B into the reactor. The polymerization occurs as the first and second mixtures of monomers are simultaneously fluxed in the reactor while stirring.

Abstract: A method of producing silicone-containing aqueous coating compositions excellent in shelf stability of the emulsion and in weather resistance, stain resistance, water resistance and solvent resistance of coatings derived therefrom is provided. The method comprises subjecting an aqueous emulsion prepared in advance by emulsification in an aqueous medium containing a polyalkoxypolysiloxane (A), an unsaturated monomer (B) and an emulsifier (C) so as to attain an oil droplet diameter not more than 1,000 nm to polymerization in the presence of a polymerization initiator (D).

Abstract: Poly(meth)acrylate dispersions, comprised of: (A) 50-90 wt. % methacrylic acid esters; (B) 5-30 wt. % acrylic acid alkyl esters; (C) 2-10 wt. % of another functionalized monomer; (D) 2-10 wt. % of a radically polymerizable carboxylic acid or a polycarboxylic acid or a partially esterified polycarboxylic acid; and (E) 0-40 wt. % of a monomer which is copolymerizable with components (A) to (D).

Abstract: Copolymerizates of methyl methacrylate and butyl methacrylate are used as plastisols in the automotive sector and as floor coverings. The invention describes a way to increase the storage stability of the plastisols by using small amounts of cross-linking agents.

Abstract: A pressure-sensitive adhesive sheet prepared by coating a composition containing a) 100 parts by weight of monomers composed of from 70 to 100% by weight of a (meth)acrylic acid alkyl ester, said alkyl group having from 2 to 14 carbon atoms, and from 0 to 30% by weight of a monoethylenically unsaturated monomer copolymerizing therewith, b) from 0.1 to 5 parts by weight of a radical chain inhibitor, c) from 0.02 to 5 parts by weight of a polyfunctional (meth)acrylate as a crosslinking agent, d) from 0.005 to 1 part by weight of a photopolymerization initiator, and e) from 0.01 to 10 parts by weight of a silane coupling agent, on a releasing-treated film having a good surface smoothness and photopolymerizing the coated layer to form a pressure-sensitive adhesive layer having a haze value of 1% or lower and a total light transmission of at least 90%.

Abstract: Polymer compositions which are useful to improve water repellency and durability in fiber, nonwoven, textile, and paper compositions are disclosed. A method of improving water repellency and durability in fiber, nonwoven, textile, and paper compositions is also disclosed.

Abstract: Poly(meth)acrylate dispersions, comprised of:

Abstract: The present invention relates to pressure-sensitive removable adhesives based on polyacrylates, characterized in that they comprise a compound of formula: wherein R1, R2 and R3, which are identical or different, represent a linear or branched C1-C8, preferably C2-C6, alkyl radical; and R4 represents H or an acyl radical COR5 wherein R5 is a linear or branched C1-C3 alkyl radical. The present invention also relates to a process for the preparation of said adhesives. The present invention further relates to adhesive labels and tapes comprising said adhesives.

Abstract: A hot-sealable coated substrate comprising a primer layer from an aqueous poly(meth)acrylate dispersion, comprised of: (A) 50-90 wt. % methacrylic acid esters; (B) 5-30 wt. % acrylic acid alkyl esters [lit., “acrylic acid acrylic esters”]; (C) 2-10 wt. % of another functionalized monomer; (D) 2-10 wt. % of a radically polymerizable carboxylic acid or a polycarboxylic acid or a partially esterified polycarboxylic acid; and (E) 0-40 wt. % of a monomer which is copolymerizable with components (A) to (D).

Abstract: Described is a polymer dispersion comprising in an aqueous medium (a) dispersed particles of a polymer containing more than from 5 to 20% by weight of &agr;,&bgr;-ethylenically unsaturated mono- or dicarboxylic acid, (b) a dissolved polymer containing from 60 to 100% by weight of &agr;,&bgr;-ethylenically unsaturated mono- or dicarboxylic acid, and (c) an alkoxylated long-chain amine. Heat-curable compositions are obtained by adding polyfunctional alcohols and, optionally, reaction accelerant. The polymer dispersions and the heat-curable compositions are suitable for use as binders for textile sheetlike structures and for moldings.

Abstract: The present invention relates to crosslinked, water-soluble or water-dispersible polyurethanes of A) at least one water-soluble or water-dispersible polyurethane prepolymer having terminal isocyanate groups of a) at least one compound having a molecular weight in the range from 56 to 300 which contains two active hydrogen atoms per molecule, b) at least one polymer containing two active hydrogen atoms per molecule, c) at least one compound which contains two active hydrogen atoms and at least one ionogenic or ionic group per molecule, d) at least one diisocyanate, B) at least one polymer containing groups which are reactive toward isocyanate groups, chosen from hydroxyl, and primary and secondary amino and/or carboxyl groups, or the salts thereof.

Abstract: Aqueous laminating construction adhesive compositions incorporating a one-part adhesive copolymer, the copolymer being a vinyl ester/acrylic copolymer containing from about 0.1% to about 20%, by weight based on copolymer weight, of a copolymerized polar monomer, the copolymer having a Tg from about 10° C. to about −35 C. are provided which exhibit a good balance of high temperature and ambient temperature adhesion performance in a one-part adhesive composition.

Abstract: The present invention relates to a water based laminating adhesive composition and a method of using thereof. More particularly, the invention relates to a water-based laminating adhesive comprising: a first component comprising at least one aqueous vinyl polymer dispersion (A) comprising the reaction product of i) at least one ethylenically unsaturated monomer; ii) at least one free radical initiator; and iii) optionally, at least one ethylenically unsaturated oligomer; and b) a second component comprising at least one water dispersible polyfunctional aziridine crosslinking agent (B). The adhesive optionally comprises at least one aqueous polyurethane polymer dispersion (C). Improved bonded properties of dry laminated flexible film substrates such as polyolefin, polyester and polyamide, as well as cellophane, metals or paper are obtained.

Abstract: Acrylic emulsion PSA polymers which when cast as a film resist water whitening by hot or ambient temperature water are provided, and are formed by copolymerizing a monomer mixture comprising at least one alkyl acrylate ester of an alcohol containing at least four carbon atoms, at least one polar comonomer and at least one partially water soluble comonomer present in an amount of at least about 7% by weight of the monomers. Polymerization is carried out in the presence of at least one nonionic surfactant containing at least about 8 moles of ethylene oxide per mole nonionic surfactant and at least one anionic surfactant containing up to about 10 moles ethylene oxide per mole anionic surfactant. There is added to the product of polymerization at least one base to produce an emulsion having a pH greater than 7 and containing particles having a mean “volume-average” particle diameter of up to about 210 nm as determined by laser light scattering.

Abstract: A method for aqueous bead-type suspension polymerization of (meth)acrylic monomers to prepare non-agglomerating, storage stable (meth)acrylic polymer beads which are extrudable at low temperatures. The invention also relates to the polymer beads and to their use as adhesive, in particular as a pressure sensitive adhesive. The invention also discloses adhesive compositions comprising the polymer beads.

Abstract: The invention provides a redispersible polymer powder based on a mixture of water-insoluble polymer and a water-soluble atomized protective colloid which can be de-activated through a pH change. In addition, the invention concerns aqueous dispersions that can be prepared with the polymer powder and the use of the polymer powder or its aqueous dispersions as a bonding agent in adhesives, plasters or paints.

Abstract: The invention pertains to an aqueous acrylic copolymer thickener particularly useful for thickening latex paints, the thickener copolymer comprising aqueous copolymerized ethylenically unsaturated monomers comprising between 10% and 90% carboxyl functional monomer, between 1% and 50% long alkyl ester of acrylate or methacrylate, and preferably between 20% and 90% methyl or ethyl acrylate or methacrylate. The mixture of monomers is mixed with water and surfactant, micronized to droplet size less than 5 microns, copolymerized to form a carboxyl functional copolymer, which is then neutralized with amine to form a thickener copolymer.

Abstract: A method for polymerizing predominantly one or more acrylate and/or vinyl acetate monomers in the presence of a latex results in high solids dispersions of polymer particles with lower viscosities than traditionally observed. A significant wt. % of added monomers can be present in large particles, having nonspherical shapes. Some of the original latex particles are retained during the polymerization and these increase the solids content and lower the viscosity by packing in the interstices between large particles. The total polymer solids content can easily be varied from 70 to 92 or more wt. % which are higher than achieved in any previously reported aqueous polymerizations. The viscosities at very high solids contents become paste-like but the materials still are stable to storage and further handling without breaking the dispersion into an agglomerated polymer portion and released water. The dispersions are useful to form sealants, membranes, etc., either with or without other additives.

Abstract: Poly(meth)acrylate dispersions, comprised of: (A) 50-90 wt. % methacrylic acid esters; (B) 5-30 wt. % acrylic acid alkyl esters, [lit., “acrylic acid acrylic esters”]; (C) 2-10 wt. % of another functionalized monomer; (D) 2-10 wt. % of a radically polymerizable carboxylic acid or a polycarboxylic acid or a partially esterified polycarboxylic acid; and (E) 0-40 wt. % of a monomer which is copolymerizable with components (A) to (D).

Abstract: An aqueous adhesive composition for wet lamination of substrate layers to form a laminated article includes from about 40 weight percent to about 65 weight percent solids dispersed in an aqueous medium, wherein the solids include a polymer having repeating units derived from a vinyl ester monomer and having a glass transition temperature of about −15° C. to about +15° C.; and from about 0.1 parts by weight to about 40 parts by weight of a plasticizer compound per 100 parts by weight of the polymer. A method for making a laminated article includes applying a wet layer of the aqueous laminating adhesive composition of the to a first substrate layer; covering the wet layer of adhesive composition with a second substrate layer; and drying the layer of adhesive composition to form the laminated article. A laminated article includes two substrate layers bonded together by an interposed layer of the dried adhesive composition.

Abstract: The present invention relates to a blend composition and a method for the use of such to improve the adhesion properties of coatings. More particularly, the present invention relates to the use of a polymeric blend containing a macromolecular aqueous dispersion, an acid-functional alkali-soluble resin, and an aminosilane in order to provide adhesion of coatings over difficult surfaces such as chalky substrates.

Abstract: Inherently tacky, pressure-sensitive adhesive compositions useful in marking film applications are provided. The compositions comprise polymer particles prepared by emulsion polymerization of at least one monomer mixture. The monomer mixture comprises at least one alkyl acrylate, the alkyl group of which has from about 4 to 12 carbon atoms, preferably in an amount of from about 73% to 90% by weight, at least one unsaturated carboxylic acid containing from about 3 to 5 carbon atoms, preferably in an amount of from about 2% to 12% by weight, and at least one hard monomer, preferably present in an amount of from about 5% to 15% by weight. The particles have a mean diameter of about 300 nm or less, as determined by laser light scattering. Preferably the hard monomer comprises a styrenic monomer, more preferably both a styrenic monomer and an alkyl methacrylate. In some embodiments, the compositions are prepared by sequential polymerization of the first and second monomer charges.

Abstract: The present invention provides a multiple part ionomeric cement system comprising an organic composition that is substantially free of added water, and an aqueous composition comprising water. The organic composition contains at least a hydrophilic component and an acid functional compound that is provided as greater than 1.0% weight of the organic composition. The liquid ingredients of the compositions are miscible, both as separate compositions and when mixed together.

Abstract: A copolymer latex with a total solids content of at least 67% by weight, which is characterized by having a viscosity of 2,000 centipoises or less as measured with a BM viscometer under the conditions of total solids content of 67% by weight and at room temperature, is provided. Such a low viscosity and high solids-content copolymer latex is produced through an emulsion polymerization in which the method of use of the emulsifier and the amount thereof are controlled following specific conditions.

Abstract: An improved method for forming book casing is provided through an adhesive composition. The adhesive provides surprising adhesion to both paper and plastic films with also allowing higher processing rates. Book casings produced with the adhesives are also claimed.

Abstract: General purpose inherently tacky acrylic pressure sensitive adhesive polymers formed of alkyl acrylates, vinyl esters, and saturated carboxylic acids, having improved properties, a lower residual monomer content are formed by a sequential emulsion polymerization process in which 40 to 70 percent, typically 45 percent, of the monomers are incrementally added to a reactor as a first charge containing substantially all of the vinyl esters, the balance of the monomers being fed in a second incremental charge.

Abstract: An aqueous adhesive composition for wet lamination of substrate layers to form a laminated article includes from about 40 weight percent to about 65 weight percent solids dispersed in an aqueous medium, wherein the solids include a polymer having repeating units derived from a vinyl ester monomer and having a glass transition temperature of about -15.degree. C. to about +15.degree. C.; and from about 0.1 parts by weight to about 40 parts by weight of a plasticizer compound per 100 parts by weight of the polymer. A method for making a laminated article includes applying a wet layer of the aqueous laminating adhesive composition of the to a first substrate layer; covering the wet layer of adhesive composition with a second substrate layer; and drying the layer of adhesive composition to form the laminated article. A laminated article includes two substrate layers bonded together by an interposed layer of the dried adhesive composition.

Abstract: The present invention is directed to improved aqueous based pressure sensitive adhesive emulsion polymers. Conventional emulsion based pressure sensitive adhesives are comprised of a copolymer comprised of polymerized units of acrylic esters and ethylenically unsaturated monomers, the copolymer having a T.sub.g of from -15 to -70.degree. C. The improvement in the aqueous based, emulsion polymerized pressure sensitive adhesives resides in the incorporation of a vinyl C.sub.8-13 ester of a neo-acid into the copolymer present in the pressure sensitive adhesives. Such vinyl ester is formed from a mixture of propylene oligomers and such vinyl ester is represented by the chemical formula C.sub.8-13 H.sub.17-27 CO.sub.2 CH.dbd.CH.sub.2.

Abstract: The present invention is a method of making a stable colloidal non-aqueous wax particle dispersion. The method includes the steps of forming a mixture of a first vinyl monomer of a polymerizable mono-alpha, beta-ethylenically unsaturated compound free of ionic charge groups and capable of addition polymerization and a second vinyl monomer capable of addition polymerization and wax particle in a aqueous medum. The mixture is polymerized using an azo or diazo initiator to form an aqueous dispersion of composite wax particles. The wax particles are redispersed in an organic solvent.

Abstract: The present invention relates to a water-based high-solids moisture-resistant latex pressure sensitive adhesive which has a low coating viscosity and which has high shear, high compliance, and controlled adhesion buildup.

Abstract: A method for polymerizing predominantly one or more acrylate and/or vinyl acetate monomers in the presence of a latex results in high solids dispersions of polymer particles with lower viscosities than traditionally observed. A significant wt. % of added monomers can be present in large particles, having nonspherical shapes. Some of the original latex particles are retained during the polymerization and these increase the solids content and lower the viscosity by packing in the interstices between large particles. The total polymer solids content can easily be varied from 70 to 92 or more wt. % which are higher than achieved in any previously reported aqueous polymerizations. The viscosities at very high solids contents become paste-like but the materials still are stable to storage and further handling without breaking the dispersion into an agglomerated polymer portion and released water. The dispersions are useful to form sealants, membranes, etc., either with or without other additives.

Abstract: A method for improving the flocculation of suspended solids in a Bayer process liquor in a primary settler stage. The method includes the step of adding to a primary settler feed a composition including water-continuous polymer, said polymer being hydrolyzable in a Bayer process liquor to an acid form, said acid form being an active red mud flocculent. A novel emulsion, and a polymerization technique for obtaining high molecular weight emulsions are also disclosed.

Abstract: Water resistant, low haze acrylic emulsion pressure sensitive adhesive compositions for use in decorative, light management or optical articles are disclosed. These emulsion pressure sensitive adhesives comprise (a) 50-90% by weight n-butyl acrylate, and (b) 10-50% by weight 2-hydroxy ethyl acrylate, or 2-hydroxy ethyl methacrylate, hydroxy propyl acrylate monomer, or mixtures thereof. These emulsion pressure sensitive adhesives can be used in wet lamination processes, and exhibit less than 2% increase in haze, less than 2% increase in opacity and greater than 95% transmittance after the wet lamination process.

Abstract: Novel latex or emulsion compositions containing internally plasticizing and crosslinkable long-chain alkenol ester monomers are disclosed and claimed. Preferred embodiments include latex formed from acrylate or methacrylate esters of long-chain alkenols. A process for the synthesis of the latex composition is also disclosed, which involves (a) esterification of a long-chain alkenol with an ethylenically unsaturated carboxylic acid; (b) polymerization of the ethylenically unsaturated ester in an aqueous phase with at least one other copolymerizable monomer; and (b) blending of so formed polymer with at least one drier and a surfactant to form the novel latex or emulsion compositions. These compositions form films at low minimum film forming temperatures (MFT) ranging from -5 to 10.degree. C. and cure to above ambient glass transition (T.sub.g) polymers without the use of traditional organic cosolvents which contribute to environmental pollution via volatile organic compounds (VOCs) emissions.

Abstract: A process for preparing aqueous polymer dispersions by emulsion polymerization of free-radically polymerizable compounds (monomers) comprises adding, during the polymerization of the monomers, a miniemulsion which is an aqueous, surfactant-stabilized emulsion of monomers whose emulsified droplets have a size of from 10 to 500 nm and which comprises a compound (stabilizer) which is dissolved in the monomers of the droplets and whose solubility in the monomers is at least twice its solubility in water.

Abstract: This invention provides an aqueous coating composition, more particularly an aqueous floor finish composition, comprising water, at least one polymeric film forming agent, and a plasticizing agent, wherein the improvement comprises at least a portion of the plasticizing agent being at least one tertiary alkyl monocarboxylic acid having an average of from about 6 to 30 carbon atoms per molecule. Such compositions have one or more improved properties such as increased hardness as compared with the same compositions using only conventional plasticizers such as tributoxyethyl phosphate, improved wetting of the substrate by the composition during application, improved coating film leveling, improved multiple coat gloss development, and improved resistance to wear, black heel marking and scuffing.

Abstract: The present invention relates to an aqueous-based coating composition for forming strippable, protective coating for protecting surfaces, such as glass, metal, ceramic, plastic or other materials of construction. More specifically, the compositions and coatings formed therefrom of this invention are particularly useful in connection with protecting precision surfaces, such as optical lenses, including but not limited to ophthalmic lenses, telescopic lenses, microscopic lenses, and the like, which protection is desirably only of a temporary nature.

Abstract: A vinyl acetate-ethylene copolymer emulsion having a solids content of at least about 65 percent by weight comprises about 5 to 40 percent by weight ethylene; about 60 to 95 percent by weight vinyl acetate; greater than about 3.0 percent by weight of a polyvinyl alcohol having a degree of polymerization of from about 100 to 500; about 1 to about 4 percent by weight of an ethyoxylated aliphatic surfactant having an HLB of from about 16.5 to 18.0; and about 0.2 to about 1.0 weight percent of a dispersant.

Abstract: Aqueous polymer emulsions are obtained by polymerizing a mixture of hydrophobic and hydrophilic ethylenically unsaturated monomers by the free radical aqueous emulsion polymerization method and using, as the dispersing medium, a mixture of water and an organic solvent which is not completely soluble in water, the amount of solvent accounting for more than 20% by weight of the total amount of monomers to be polymerized.

Abstract: It has been determined that rubbery terpolymers of a conjugated diolefin monomer, a vinyl aromatic monomer, and N-(isobutoxymethyl) acrylamide (IBMA) can be used to modify asphalt cement to greatly enhance the resistance to shoving, rutting, and low temperature cracking of asphalt concretes made therewith. These rubbery polymers have a Mooney viscosity which is within the range of about 35 to about 80. It has further been determined that these rubbery terpolymers are compatible with virtually all types of asphalt. It is particularly preferred for the rubbery polymers of this invention to also contain repeat units which are derived from hydroxypropyl methacrylate (HPMA).

Abstract: Aqueous composition intended to form an antimigration and antiozone protective coating on the external surface of a tire, comprising an aqueous emulsion of at least: (a) a polymer called constituent I, said constituent I being a homopolymer or copolymer based on at least one monomer chosen from the group of acrylic, methacrylic and vinyl esters and having a glass transition temperature below 0.degree. C.; and (b) a constituent II chosen from the group consisting of a hydrophilic silica and a homopolymer or copolymer based on at least one monomer chosen from the group of acrylic, methacrylic and vinyl monomers, said homopolymer or copolymer having a glass transition temperature above 25.degree. C.

Abstract: A process for producing an aqueous dispersion-type acrylic polymer is disclosed, which comprises introducing a monomer comprising an alkyl (meth)acrylate as the main component into a polymerization vessel at a time at a monomer concentration of 40% by weight or higher, adding a water-soluble radical polymerization initiator thereto in an amount of from 0.001 to 0.05 parts by weight per 100 parts by weight of the monomer, and emulsion-polymerizing the monomer substantially at 20.degree. to 60.degree. C. The aqueous dispersion-type acrylic polymer thus obtained satisfies the equation log M>3log S-2, wherein S is a tetrahydrofuran (THF)-soluble content (wt %) of the polymer and M is a weight-average molecular weight (.times.10,000) of a soluble part of the polymer. This polymer is preferably used for a pressure-sensitive adhesive in pressure-sensitive adhesive-covered products.

Abstract: Water retention additives for aqueous construction systems including joint compounds are described which are the reaction product of monomers comprising carboxylic acid monomers, nonionic vinyl monomers and specific surfactant monomers. Processes for making such polymers are described as well as the use of aqueous construction systems using the polymers. The polymers are useful in joint compounds and a broad range of similar construction systems as cellulosic replacements.

Abstract: A method of producing low-viscosity water-based water-soluble polymer dispersions having a high concentration of the principal substance is achieved by polymerizing the following monomer components,(a1) 50-99.999 wt. % of at least one water-soluble monomer;(a2) 0.001-1 wt. % of at least one crosslinking monomer with at least two ethylenically unsaturated radically polymerizable groups;(a3) 0-30 wt. %, particularly 1-25 wt. %, of at least one hydrophobic monomer; and(a4) 0-25 wt. %, particularly 0.1-15 wt. %, of at least one amphiphilic monomer,in aqueous solution, in the presence of at least one polymer dispersant, to form a polymer (A), where the sum of the amounts of the components represented by the monomers (a1), (a2), (a3), and (a4) is 100 wt. % of the monomers, the weight average molecular weight of the resulting polymer (A) is at least 500,000 Dalton, and polymer (A) is incompatible with the dispersant.

Abstract: Method for homopolymerization of polyorganosiloxane macromonomers having acryloxy or methacryloxy groups. A miniemulsion of a methacryloxy functional polydimethylsiloxane macromonomer was prepared by mixing the macromonomer with a surfactant(s), and subjecting it to a high shear device. The macromonomer was polymerized in the miniemulsion by using a free radical initiator at high temperature. The amount of unreacted macromonomer is very low.

Abstract: An emulsion compositions comprising (i) an alkyl-modified carboxyvinyl polymer, (ii) a C.sub.12 to C.sub.18 higher alcohol solid at room temperature (for example 15.degree. to 20.degree. C.), and (iii) a silicone oil, wherein the weight ratio of the component (i)/component (ii) is not more than 0.5. This emulsion further contains no surfactant.

Abstract: This invention relates to dicyclopentyl-oxyethyl methacrylate acrylic copolymer latices forming photocurable coalesced films and prepared by adding a photoinitiator to the latex, and which are useful for preparing lacquers and paints, particularly for building facades.

Abstract: New environmentally friendly, water-based, silicone-resin compositions for mold release, substrate surface treatment or other applications are described. The invention uses a non-traditional dispersing technology and offers a catalytic system for the faster cure of the silicone resin. Said compositions comprise a silicone resin, a hydrophobically modified polycarboxylic acid copolymer dispersion stabilizer and water. The composition may also contain one or more of the following components: a gelling control agent, a catalyst, a particle-size reducing agent, a thickening agent, a wetting agent, a surface modifier, an anticorrosion agent, a preservative, and other optional additives.

Abstract: A process for the preparation of an aqueous polymer emulsion, in which an aqueous emulsion of a polymer which contains at least one chemically bonded monomer having at least one ethylenically unsaturated group is produced in a manner known per se so that the total content of free monomers having at least one ethylenically unsaturated double bond, ie. monomers of this type which are not chemically bonded, in the aqueous polymer emulsion is from >0 to .ltoreq.1% by weight, based on the polymer content of the aqueous polymer emulsion, and this residual monomer content is then reduced by the action of a free radical redox initiator system comprising at least one oxidizing agent and at least one reducing agent, wherein the redox initiator system comprises, as the reducing agent, one which is present, in aqueous solution, in at least two tautomeric forms in equilibrium with one another (for example aminoiminomethanesulfinic acid and/or the salts thereof).

Abstract: A method for polymerizing at least one unsaturated monomer in the presence of a latex results in a high solids dispersion of polymer particles with lower viscosities than traditionally observed. A significant wt. % of the polymer from added monomers can be present in large particles, having nonspherical shapes. Some of the original latex particles are retained during the polymerization and these increase the solids content and lower the viscosity by packing in the interstices between large particles. The total polymer solids content can easily be varied from 70 to 92 or more wt. %. The viscosities at very high solids contents become paste-like but the materials still are stable to storage and further handling without causing the dispersion to separate into an agglomerated polymer portion and released water. The dispersions are useful to form sealants, membranes, etc., either with or without other additives.