Abstract: A low formaldehyde high gel fraction latex binder is made utilizing a compound having the formula ##STR1## wherein R and R', independently, is an alkyl having from 1 to 10 carbon atoms, and R.sup.4 is hydrogen, or wherein R.sup.3 and R.sup.4, independently is an alkyl, an aromatic, or combinations thereof having from 1 to 10 carbon atoms, or wherein said R.sup.3 and R.sup.4 are connected to form an internal amide, and wherein the isopropenyl group is either in the ortho, meta or para position. The latex binder is generally an emulsion or latex copolymer made from various monomers including at least one or more conjugated dienes having a total of from 4 to 10 carbon atoms with butadiene being preferred and from one or more vinyl-substituted aromatics having from 8 to 14 carbon atoms, with styrene being preferred. The amount of the above formulation compounds is generally from about 0.

Abstract: An electrophoresis separation layer is produced which comprises a polyacrylamide gel which remains stable even when stored for a long time and is available for analyzing substances of an extremely wide molecular weight range in electrophoresis for determining molecular weight. The electrophoresis separation layer of the present invention includes a polyacrylamide gel with an aqueous solution containing an amine of a specific pH value, an ampholyte and an acid at a specific ratio as an electrolytic solution in the gel. This separation layer can be produced by lowering the pH value of the electrolytic solution in the polyacrylamide gel to such an extent as not to cause any hydrolysis of amide while achieving a suitable potential gradient distribution in the gel during the electrophoresis.

Abstract: The invention relates to aqueous dispersions of water soluble polymers, formed by polymerization of a mixture A of various monomer components (a1, a2, and possibly a3) in the presence of a polymeric dispersant D; wherewith the mixture A is comprised of the following different monomera1 (in the amount of 99-70 wt. %), comprised of at least one water soluble monomer,a2 (in the amount of 1-30 wt. %), comprised of at least one hydrophobic monomer, and (possibly)a3 (in the amount of 0-20 wt. %), comprised of at least one amphipathic monomer, wherewith in each instance the sum of the amounts of a1, a2, and a3 is 100%;and wherewith the water soluble polymers have a mean molecular weight M.sub.w (gravimetric mean) of at least 10.sup.6 Dalton.

Abstract: A method for reducing the amount of microfoam in a spray-applied clear waterborne polymeric composition is provided, wherein the clear composition contains certain emulsion-polymerized addition polymers or certain multi-staged emulsion-polymerized addition polymers is formed; is spray-applied to a substrate; and is dried. Also provided are substrates bearing such spray-applied clear compositions.

Abstract: A low formaldehyde, high gel fraction latex binder is made utilizing a compound having the formula ##STR1## wherein R and R', independently, is an alkyl having from 1 to 10 carbon atoms, and R.sup.4 is hydrogen, or wherein R.sup.3 and R.sup.4, independently is an alkyl, an aromatic, or combinations thereof having from 1 to 10 carbon atoms, or wherein said R.sup.3 and R.sup.4 are connected to form an internal amide, and wherein the isopropenyl group is either in the ortho, meta or para position. The latex binder is generally an emulsion or latex copolymer made from various monomers including at least one or more conjugated dienes having a total of from 4 to 10 carbon atoms with butadiene being preferred and from one or more vinyl-substituted aromatics having from 8 to 14 carbon atoms, with styrene being preferred. The amount of the above formulation compounds is generally from about 0.

Abstract: In a papermaking process, improved drainage and retention are obtained when ionic, organic microbeads of less than about 1,000 nm in diameter if crosslinked or less about than 60 nm in diameter if noncrosslinked are added either alone or in combination with a high molecular weight organic polymer, and/or polysaccharide. Further addition of alum enhances drainage formation and retention properties in papermaking stock with and without the present of other additives used in papermaking processes.

Abstract: Aqueous polyurethane dispersions are prepared by reacting (a) dihydroxy compounds having a molecular weight of from 500 to 5,000, (b) diisocyanates and, if required, (c) chain extenders having at least two hydrogen atoms which are reactive toward isocyanate groups and a molecular weight of less than 300 in the melt or in the presence of a water-miscible, inert organic solvent (S) which boils below 100.degree. C. to give a prepolymer having terminal isocyanate groups, then reacting the prepolymer with (d) salts of aliphatic aminocarboxylic or aminosulfonic acids or tertiary ammonium salts and dispersing the resulting polyurethane in water, by a process in which, before the polyurethane obtained is dispersed in water, from 5 to 60 parts by weight, based on 100 parts by weight of the polyurethane, of a polymer (p) [sic]which is dissolved in a solvent (S') boiling below 100.degree. C.

Abstract: Electrophoretic media based on polymers with novel structures are disclosed. The polymers are formed by polymerization of acrylamide monomers, such as N-methylolacrylamide, with cross-linking agents or comonomer agents such as tetraethylene diacrylate and bisacrylamide methylether.

Abstract: Stable emulsions and dispersions of both the water-in-oil and oil-in-water types are prepared by subjecting mixtures of the two phases to shear stress in the presence of nitrile group-containing copolymers capable of forming hydrogels containing at least 90% by weight of water at room temperature.

Abstract: An aqueous vinyl acetate/N-methylolacrylate copolymer emulsion for RF curable Type I wood adhesive compositions prepared by the polymerization of vinyl acetate and N-methylolacrylamide in the presence of 1 to 5 wt% tetramethylol glycoluril and a stabilizing system consisting essentially of 3 to 5 wt% polyvinyl alcohol, the weight percentages being based upon vinyl acetate monomer.

Abstract: An invert microlatex of at least one cationic water-soluble vinyl monomer, if necessary copolymerized with at least one anionic or non-anionic water-soluble vinyl monomer, is prepared by a process consisting in a first stage (a) of preparation of an invert microemulsion (of the water-in-oil type) and a second stage (b) in which the invert microemulsion obtained in stage (a) is subjected to conditions of polymerization, stage (a) consisting in mixing: (A) an aqueous solution of at least one cationic water-soluble vinyl monomer, if necessary mixed with at least one anionic or non-ionic water-soluble vinyl monomer, (B) an oil phase containing at least one liquid hydrocarbon, and (C) at least one non-ionic surface active agent, in a proportion sufficient to obtain an invert microemulsion, and having an HLB, either between 11 and 15 when the cationic water-soluble vinyl monomer is alone or mixed with an anionic water-soluble vinyl monomer, or between 7.

Abstract: A coating of hydrophobic polymer is prepared by contacting a substrate with an aqueous media containing amphiphilic polymer and polymerizing polymerizable component to provide the hydrophobic polymer coating. The processes can be used to make stable dispersions of particles, such as pigments, for paint compositions.

Abstract: Wet adhesion, ICI viscosity, and scrub resistance of a paint are improved by incorporating into the paint a binder that comprises a film former and polymeric composition. The polymeric composition comprises either (a) about 15 to about 35 weight percent of substantially non-self-polymerizable monomer, about 30 to about 70 weight percent of a copolymerizable monomer whose homopolymer is water-soluble, and about 10 to about 35 weight percent of a wet adhesion promoting monomer, or (b) about 35 to about 65 weight percent of the substantially non-self-polymerizable monomer and about 35 to about 65 weight percent of the wet adhesion promoting monomer. The polymeric composition and film former are substantially inseparable by chromatographic means.

Abstract: A method for producing expandable thermoplastic microspheres by polymerisation in a reaction vessel of an ethylenically unsaturated monomer or a mixture of monomers in an aqueous suspension in the presence of a condensed propellant. In the method, the monomer or monomer mixture is suspended in the aqueous medium in the presence of a powder stabilizer which consists of a salt or hydroxide of any of the metals Ca, Mg, Ba, Fe, Zn, Ni or Mn. The powder stabilizer is insoluble in the aqueous medium at the pH the aqueous medium has at the polymerisation. The aqueous medium has at the polymerization. The aqueous medium may also contain a co-stabilizer. The method further comprises the step of washing off the powder stabilizer from the microspheres after the polymerization by lowering the pH of the aqueous medium by the addition of acid. Alternatively, amphoteric hydroxides can also be dissolved by a pH increase.

Abstract: A method for molding ceramic powders comprises forming a slurry mixture including ceramic powder, a dispersant, and a monomer solution. The monomer solution includes at least one monofunctional monomer and at least one difunctional monomer, a free-radical initiator, and a aqueous solvent. The slurry mixture is transferred to a mold, and the mold containing the slurry mixture is heated to polymerize and crosslink the monomer and form a firm polymer-solvent gel matrix. The solid product may be removed from the mold and heated to first remove the solvent and subsequently remove the polymer, whereafter the product may be sintered.

Abstract: A process for preparing a dispersion of a filler e.g., melamine, urea or borax in a dispersion or graft polymer polyol is provided. The process comprises (1) dispersing the filler in a suitable basestock (e.g., a polyether polyol) and (2) thereafter using this as the basestock for preparing the dispersion or graft polymer polyol.The polymer which is prepared in dispersed form in the second step may be for example (1) the reaction product of a polyamine, hydrazine or hydrazide and an isocyanate (PHD polymer) or (2) the reaction product of an olamine and an isocyanate (PIPA polymer). Alternatively styrene and acrylonitrile can be graft polymerised in the basestock in step (2). The new dispersion or graft polymer polyols containing dispersed filler are useful in the manufacture of fire resistant polyurethane foam for e.g., furniture applications.

Abstract: A Mannich emulsion containing a stabilizing amount of a guanidine salt has been found to exhibit substantially increased long term stability, even at elevated temperature.

Abstract: An aqueous polymeric gel-forming composition which slowly crosslinks to form stable gels for plugging highly permeable zones in subterranean oil-bearing formations. The composition comprises an aqueous solution of a water-dispersible polymer present in a viscosifying amount and a crosslinking agent present in an amount effective to cause gelation of the polymeric solution which comprises a mixture of an aldehyde and a member selected from the group consisting of phenolic esters, naphtholic esters, halogenated phenolic esters and halogenated naphtholic esters.

Abstract: An optically transparent aqueous intumescent gel for use with transparent laminates comprising about 5 to 30% by weight acrylamide, about 0 to 4% by weight of a crosslinking agent, about 5 to 28% by weight of an ammonium or alkali metal salt of an alkanoic acid having 1 to 4 carbon atoms, about 0.05 to 10% by weight of a polymerization catalyst, and water, and a laminate with the gel.

Abstract: Functionalized polymer microparticles having particle diameters of from about 200 to about 4000.ANG. are prepared and are useful in facilitating a variety of flocculation and thickening of dispersions of suspended solids applications.

Abstract: This invention describes novel hydrophobically associating ter or tetra polymers which can contain sulfonate functionality which are useful as aqueous fluid rheology or flow modifiers. These high molecular weight water soluble polymers contain both water soluble and water insoluble monomers. The water soluble monomers are N, N dimethylacrylamide acrylamide (DMA) and optionally a salt of an ethylenically unsaturated sulfonic acid (s) or N-vinylpyrrolidinone or a metal acrylate and the water insoluble monomer is a higher alkyl acrylamide (R). The process for their preparation relies on solubilizing the water insoluble monomer into an aqueous micellar solution containing one or more surfactants and the water soluble monomers. The surfactants are specifically selected to enable homogeneous dispersion of the hydrophobic monomer(s) in the presence of anionic sulfonate containing monomers.

Abstract: The invention provides a substantially dry particulate composition comprising a polyacrylamide and an amidase. An aqueous composition made by dispersing this into water will then have a satisfactorily low content of residual acrylamide even if the initial polymer was contaminated with monomer. The composition is made by blending dry polyacrylamide particles with the amidase.

Abstract: A toner for electrophotography produced by polymerizing a monomer dispersed by emulsification in the presence of a colorant and/or a magnetic powder, followed by coagulation is excellent in properties, particularly in cleaning properties, charge stability and caking resistance.

Abstract: Process for treating an aqueous solution of acrylamide resin, characterized in that an emulsifier which is preferably nonionic or anionic, a solution of initiator comprising an organic peroxide, preferably a diperoxide, and optionally a solution of a retarder preferably consisting of a phenol derivative or an alkali metal inorganic derivative are added slowly and with stirring, preferably in the form of a pre-emulsion, to an aqueous solution of acrylamide resin monomer.

Abstract: A process for preparing aqueous polymer solutions wherein a section of a fluid conduit through which a stream of liquid polymer product flows contains spaced static mixers. Heated water from a heat exchanger surrounding the section of conduit containing the mixers is introduced to a reactor to function as reaction water. The static mixers are spaced apart enough to enable the heat exchanger to sufficiently cool the liquid polymer product. The mixers function to mix other liquid agents with the liquid polymer product and to mix together warmer and cooler quantities of liquids encountered in the conduit.

Abstract: Water-in-oil emulsions of water-soluble polymers, i.e. polyacrylamides, which are subject to freeze-thaw degradation are stabilized against repeated freeze-thaw cycles by incorporating specific substituted succinic anhydrides.

Abstract: Sizing agents for paper are based on finely divided aqueous dispersions of copolymers obtainable by copolymerizing from 40 to 140 parts by weight of a monomer mixture of(a) from 20 to 65% by weight of (meth)acrylonitrile,(b) from 35 to 80% by weight of one or more acrylates of monohydric saturated C.sub.3 -C.sub.8 -alcohols and(c) from 0 to 10% by weight of other ethylenically unsaturated copolymerizable monomers,the weight percentages (a), (b) and (c) always adding up to 100, in the manner of an emulsion polymerization in 100 parts by weight of an aqueous solution containing in solution from 2.7 to 15% by weight of a degraded starch having a viscosity n.sub.i from 0.04 to less than 0.12 dl/g at from 40.degree. to 100.degree. C. in the presence of a peroxide initiator.

Abstract: Polymer water-in-oil emulsions for the production of aqueous flocculants solutions are described in which the oil phase consists entirely or to a large degree of readily biodegradable compounds and these compounds are aliphatic dicarboxylic esters.

Abstract: A method and apparatus for continuously manufacturing water absorbing resin. A mixed monomer solution is stored in a storage vessel and a polymerization initiator stored in an initiator storage vessel. The monomer solution is fed by gravity or otherwise through a conduit to a lower position (below the liquid surface) of a reaction chamber of a reaction vessel at a rate of, for example, 4 gallons per minute. Simultaneously, the polymerization initiator is fed at a rate of, for example, 0.2 gallons per minute by gravity or otherwise through a conduit to an opposite side of the reaction chamber, again at a lower portion (below a continuously maintained liquid level) to begin polymerization. The reaction product forms from an upper surface of the reactant mixture (mixed monomer solution plus initiator) and travels upwardly through a truncated frustoconical cone shaped upper portion of the reaction chamber as a solid resin.

Abstract: Disclosed is a process for preparing relatively low molecular weight, water absorbing, acrylic polymers for use as drilling fluid additives by aqueous polymerization of (A) an acrylic monomer, such as acrylic acid neutralized 0 to 100 mole percent with, for example, ammonia, and/or an alkali such as Na.sub.2 O.sub.3, and/or an amine; with (B) acrylamide in a mole ratio of 70 to 100 mole percent (A) to 30:0 mole percent (B). The molecular weight is limited to 1,000 to 50,000, such as by adding a chain transfer agent to the polymerization mixture, to achieve excellent results as a drilling fluid additive. The monomer, such as partially neutralized acrylic acid, is polymerized in aqueous solution in the presence of a polymerization initiator without external heating while allowing water to evaporate off.

Abstract: A water-in-oil emulsion, the aqueous phase of which contains Amidase. An improved method of treating water-in-oil emulsions of acrylamide polymers with Amidase to reduce the acrylamide content thereof which comprises adding the Amidase in the form of a water-in-oil emulsion.

Abstract: Water-in-oil emulsions of water-soluble polymers, i.e. polyacrylamides, which are subject to freeze-thaw degradation are stabilized against repeated freeze-thaw cycles by incorporating specific substituted succinic anhydrides.

Abstract: Acrylic resin dispersions are prepared by a monomer addition process in the presence of a free-radical initiator and an emulsifier, wherein a portion of the emulsifier is dissolved in the initial aqueous phase and the remaining portion in the added monomer phase. The new process decreases the formation of coagulates, reduces the required amount of emulsifier, and allows the preparation of dispersions of resins incorporating a large proportion of units derived from water-soluble monomers, such as carboxylic acids.

Abstract: This invention provides organic solid solutions which exhibit nonlinear optical properties.Illustrative of the invention is an optically clear solid solution of poly(N,N-dimethylacrylamide) and 13,13-di(n-hexydecylamino)-14,14-dicyano-4,5,9,10-tetrahydropyrenoquinodim ethane.

Abstract: A water-in-oil emulsion, the aqueous phase of which contains Amidase. An improved method of treating water-in-oil emulsions of acrylamide polymers with Amidase to reduce the acrylamide content thereof which comprises adding the Amidase in the form of a water-in-oil emulsion.

Abstract: Disclosed is a process for preparing relatively low molecular weight, water absorbing, acrylic polymers for use as drilling fluid additives by aqueous polymerization of (A) an acrylic monomer, such as acrylic acid neutralized 0 to 100 mole percent with, for example, ammonia, and/or an alkali such as Na.sub.2 O.sub.3, and/or an amine; with (B) acrylamide in a mole ratio of 70 to 100 mole percent (A) to 30:0 mole percent (B). The molecular weight is limited to 1,000 to 50,000, such as by adding a chain transfer agent to the polymerization mixture, to achieve excellent results as a drilling fluid additive. The monomer, such as partially neutralized acrylic acid, is polymerized in aqueous solution in the presence of a polymerization initiator without external heating while allowing water to evaporate off.

Abstract: An improved method for reducing the acrylamide present water-in-oil emulsions of acrylamide polymers with amidase which comprises adding the amidase to the water-in-oil emulsion of the acrylamide polymer upon completion of its polymerization and then subjecting the thus treated water-in-oil emulsion to one or more of the following steps:(a) pH adjustment(b) heating(c) inert gas sparging(d) adding a chemical reducing agent.

Abstract: By a new process, inverse microlatices of watersoluble copolymers are prepared by copolymerization within an inverse microemulsion obtained by admixing an aqueous phase containing the hydrosoluble monomers to be copolymerized, an organic phase and a non-ionic surfactant or a mixture of non-ionic surfactants, whose H L B ranges from 8 to 11.The resultant microlatices can be diluted in water so as to form thickened solutions, which can be used to improve the production of hydrocarbons from oil formations, particularly in enhanced recovery methods or methods for preventing water inflows in producing wells.

Abstract: A method for forming shaped hydrogel articles such as soft contact lenses wherein hydrophilic monomers are mixed with an inert diluent prior to polymerization, and the diluent is replaced with water following the polymerization. Diluents yielding optically clear hydrogels with good mechanical properties are selected on the basis of their viscosity and their Hanson cohesion parameters relative to the cohesion parameters of the polymeric component of the hydrogel.

Abstract: A polymaleate having an average molecular weight of 300 to 5000 is obtained by polymerizing a monoalkali metal maleate or monoammonium maleate at 80.degree. to 180.degree. C. in the presence of a polymerization initiator in an aqueous solvent.

Abstract: Beads comprising a polymeric matrix containing a releasable lipophilic compound are made by precipitating the compound from solution within the matrix. Beads may be made by forming a homogeneous blend of the compound in lipophilic polymerizable material and subjecting the blend to bead polymerization while the blend is dispersed as beads in an aqueous medium containing hydrophilic polymerization stabilizer. The lipophilic compound may be a behenyl ester wax inhibitor or other reagent useful downhole or for other purposes and preferably has a relatively high melting point. The polymerizable material preferably dissolves the lipophilic compound and may include acrylic acid, methacrylic acid or other hydrophilic polymerizable material.

Abstract: Concentrated, stable water-in-oil emulsions of water-soluble or water-swellable polymers are prepared by polymerization of one or more water-soluble ethylenically unsaturated monomers in a water-in-oil emulsion and removal of water from the water-in-oil polymer emulsion by azeotropic distillation, by a method in which superheated vapor of an inert organic solvent which is immiscible with water is passed into the water-in-oil polymer emulsion. Using the process, it is also possible to concentrate emulsions which tend to coagulate or water-in-oil emulsions which are sensitive to shearing, without the polymers losing their effectiveness.

Abstract: A process for producing an aqueous partially hydrolyzed polyacrylamide solution employed to recover oil from a subterranean oil-bearing formation. The properties of viscosity and screen factor for an aqueous polymer solution are correlated to the polymerization reaction parameters. Values of the parameters are selected which correlate to the specific predetermined polymer properties capable of meeting the performance demands of the formation and the aqueous partially hydrolyzed polyacrylamide solution is produced at the selected values of the reaction parameters.

Abstract: Disclosed is a process for preparing water absorbing, cross-linked acrylate resins by aqueous polymerization of (A) acrylic acid neutralized 70 to 100 mole percent for example with ammonia, and/or caustic alkali and/or an amine; with (B) acrylamide in a mole ratio of 70 to 100 mole percent (A) to 30:0 mole percent (B); and (C) a water miscible or a water soluble polyvinyl monomer in an amount of 0.001 to 0.3 weight percent based on the total weight of (A) and (B). In accordance with one embodiment of the invention, the concentration of monomers (A) plus (B) should be at least 70 percent by weight of the polymerization mixture of (A) plus (B) plus (C) to achieve a substantially dry polymer (less than 15 weight percent water) when polymerization is completed by utilizing the exothermic heat of polymerization and cross-linking to drive off water without the need for additional heating to obtain a dry solid.

Abstract: A method for preparing dilute aqueous polymer solutions, especially dilute aqueous partially hydrolyzed polyacrylamide solutions, for use in secondary and tertiary oil recovery processes. The method comprises producing a concentrated polymer solution in a polymerization reactor and diluting the resulting gel-like, relatively high concentration polymer solution to obtain a free-flowing, relatively low concentration polymer solution by means of a staged dilution process. In each stage, an aqueous diluent is combined with the polymer solution to produce a nonuniform mixture which is maintained in a vessel in a quiescent state until the mixture becomes uniform. The stages are repeated as many times as necessary until the free-flowing, relatively low concentration polymer solution is obtained.

Abstract: Provides new and improved water-reducible coating compositions and methods of making them. Three preferred processes are disclosed. These differ in the manner of incorporating and chemical nature of an extender polymer.Broadly, the process of the invention is one for forming an aqueous dispersion of a fluent resinous composition ofa. a mixture in an organic solvent of(i) an ionizable graft polymer of an epoxy resin and an addition polymerized resin, the addition polymerized resin being bonded to aliphatic backbone carbon atoms of the epoxy resin by carbon-to-carbon bonds, and(ii) an extender resin;b. an aqueous vehicle, andc. an ionizing agent;the ionization present from said combined components being sufficient to establish the components as a dispersion in the aqueous vehicle, and then addition polymerizing a quantity of addition polymerizable monomer, under addition polymerizing conditions, in said aqueous dispersion, the aqueous dispersion serving as a vehicle therefor.

Abstract: An on-site, in-line process and system for recovering oil from oil-bearing subterranean formations which involves the production, modification, dilution and injection of a polymer solution, preferably consisting essentially of an aqueous solution of a partially hydrolyzed polyacrylamide, having injectivity and mobility properties capable of meeting the specific permeability requirements of substantially any subterranean formation to be achieved. The polymer solutions prepared by the process and system can be used as drive fluids for displacing oil (secondary polymer flood) in an oil-bearing formation, as mobility buffers to follow micellar dispersion floods in the conjoint presence of chemical reagents in other chemical floods (e.g., surfactant, caustic, etc.), or they can follow a water flood. The solutions can also be used to promote pipelining of high viscosity crude oil.

Abstract: A method for the on-site continuous preparation of aqueous solutions of polymers, especially aqueous solutions of partially hydrolyzed polyacrylamides, for use in secondary and tertiary oil recovery processes. The method utilizes an apparatus comprised of a polymerization reactor and a post polymerization reactor. Successive batches of an initiated reaction mixture are sequentially fed into the polymerization reactor in discrete volumes. The volumes are moved through the polymerization reactor at a rate such that when a volume reaches the outlet of the polymerization reactor, the reaction will have gone to substantial completion. The resulting polymer solution is withdrawn from the polymerization reactor and continuously conveyed to the post polymerization reactor. Enroute dilution water and a polymer modifying agent are continuously introduced into the polymer solution to form a second reaction mixture.

Abstract: A process for the preparation of aqueous polymer dispersions comprising polymerizing compounds with unsaturated ethylenic bonds at a temperature of 10.degree. to 100.degree. C. in the presence of an at least partially water-soluble free-radical initiator and at least one water-soluble protein and optionally present conventional adjuvants with the starting mixture containing not more than 40% of the total monomers and the remaining monomer being added by metering during the polymerization, the initiators being at least one member of the group consisting of ketone peroxides and organic hydroperoxides in an amount of at least 30 mmol per kg of total monomer mixture and optionally present water-soluble reducing agents and the amount of protein being at least 3% by weight based on the total monomer weight and at least 30% by weight is added during the polymerization and the isoelectric point of the protein is not reached or exceeded during polymerization.

Abstract: A process for the preparation of aqueous polymer dispersions comprising polymerizing vinyl esters and up to 50% by weight of the total monomer of compounds with unsaturated ethylenic bonds at a temperature of 10.degree. to 100.degree. C. in the presence of an at least partially water-soluble free-radical initiator and at least one starch member of the group consisting of cyanalkylated starch, hydroxyalkylated starch and carboxyalkylated starch and optionally present conventional adjuvants with the starting mixture containing not more than one-third of the total monomers and the remaining monomers being added by metering during the polymerization, the initiators being at least one member of the group consisting of hydrogen peroxide and organic hydroperoxides in an amount of at least 30 mmol per kg of total monomer mixture and optionally present water-soluble reducing agent and the amount of starch being at least 1% by weight based on the total monomer weight.