Abstract: A two-step emulsion polymerization method for making an aqueous emulsion of core/shell polymer particles recoverable as a polymer powder by spray drying the emulsion, said polymer being capable of swelling and forming a gel in gasoline, and paints and coating compositions containing gasoline and such a polymer powder as a thickening agent or binder.

Abstract: A method for making an aqueous polymodal synthetic resin dispersion by the emulsion polymerization of an ethylenically unsaturated monomer difficultly soluble in water, or a mixture of such monomers forming a polymer which is water insoluble under the conditions of polymerization, in an aqueous phase containing an emulsifier and a water soluble polymerization initiator, which method comprises adding a seed latex to the polymerization mixture in the course of the emulsion polymerization before more than 40 weight percent of said monomers have been polymerized, the particles of said seed latex being smaller by a factor ranging from 2 to 15 than are particles already formed by emulsion polymerization, the amount by weight of the particles in the seed latex being not greater than 10 percent by weight of the monomers and the ratio by weight of particles of said seed latex to the weight of the monomers already polymerized being from 1:4 to 1:500.

Abstract: What is disclosed is a method for making a substantially salt free solid polymer product from an emulsion polymer prepared with the aid of a free emulsifier acid having a pKa in the 1.0 to 4.5 range, the dispersion so obtained being precipitated by the addition thereto of a strong acid.

Abstract: A method for making impact resistant molding compositions wherein a hard phase having a glass transition temperature above 25.degree. C. and consisting principally of methyl methacrylate is polymerized at least partially in a first stage, following which the monomers of a rubbery phase whose polymers have a glass transition temperature below 25.degree. C. are added in a second stage and the polymerization is carried to completion, polymerization of the hard phase in the first stage being performed in a presence of an oil soluble free radical initiator and of an organosulfur chain transfer agent having at least two thiol groups in the molecule, and polymerization of the monomers of the rubbery phase in the second stage being carried out with graft crosslinkers in the presence of the previously formed hard phase.

Abstract: What are disclosed are methods for dispersing a powdered salt-forming synthetic resin in water in the presence of an agent forming a salt with said resin, methods for coating pharmaceutical dosage forms with a dispersion made by such a method, and powdered mixtures of a salt forming resin and salt forming agent for dispersion in water.

Abstract: An emulsion polymer comprising a hard nonelastomeric core, an elastomeric intermediate stage produced in the presence of the core and essentially composed of an acrylic ester and a crosslinking monomer which contains three or more acrylic or methacrylic groups in the molecule, and a hard nonelastomeric final stage produced in the presence of the elastomeric intermediate stage and crosslinked therewith, said polymer being useful as an impact strength modifying agent which, in admixture with a thermoplastic polymethyl methacrylate molding compound for example, yields molded articles exhibiting reduced susceptibility to stress whitening and improved impact strength.

Abstract: What are disclosed are a method for the reinforcement of a fibrous article with an aqueous dispersion of a resin, free of formaldehyde and acrylonitrile, comprising at least 40 weight percent of alkyl acrylates and/or methacrylates having at least 4 carbon atoms in the alkyl group; up to 57 weight percent of alkyl acrylates or methacrylates having not more than 3 carbon atoms in the alkyl group, or of styrene; less than 1 weight percent of acrylic acid or of methacrylic acid; and from 3 to 15 weight percent of a hydroxyalkyl ester of an unsaturated carboxylic acid, as well as reinforced fibrous articles made by this method and distinguished by high wet strength and by low loss of the resin binder on washing with boiling water.

Abstract: What are disclosed are aqueous dispersions of a self-crosslinking synthetic resin, said dispersions consisting of an aqueous phase containing from 0.2 to 5 weight percent of urea and, dispersed therein, resin particles formed of a vinyl polymer comprising (a) from 52.1 to 97.9 weight percent of acrylate or methacrylate esters, vinyl esters, or styrene; (b) from 0.1 to 10 weight percent of N-methylol acrylamide or methacrylamide; (c) from 2 to 10 weight percent of an hydroxyalkyl ester of an unsaturated carboxylic acid; and (d) 0 to 27.9 weight percent of other monomers, which dispersions, on drying and condensation to form films, liberate much less formaldehyde than comparable dispersions without urea while retaining good solvent resistance.

Abstract: What are disclosed are a method for making non-blocking soft polymer beads by applying an adherent polymer deposit on the beads, said deposited polymer having a glass transition temperature at least 10.degree. C. higher than the glass transition temperature of the soft polymer beads, which latter temperature is below 70.degree. C., and non-blocking soft polymer beads made by this method.

Abstract: What is disclosed is making highly concentrated, bimodal, aqueous synthetic resin dispersions by the emulsion polymerization of ethylenically unsaturated monomers, in the presence of emulsifiers and free radical-forming initiators, by adding to a first latex containing a first dispersed synthetic resin and an aqueous phase, a second latex containing a second dispersed synthetic resin and an aqueous phase and a monomer phase containing a free-radically polymerizable monomer, and then polymerizing the monomer, the average size of the particles of said first resin differing by a factor between 2 and 15 from that of the particles of second resin, the total weight of the resins and monomers representing 100 parts by weight, and the total weight of the aqueous phases representing not more than 70 parts by weight.

Abstract: What are disclosed are aqueous dispersions of an acrylic resin which is suitable for the reinforcement of fibrous articles and is free of formaldehyde and acrylonitrile, said resin comprising (a) from 70 to 96.95 weight percent of alkyl esters of acrylic acid and/or methacrylic acid, or mixtures of such esters with styrene; (b) from 2 to 30 weight percent of an hydroxyalkyl ester of an unsaturated carboxylic acid; (c) from 1 to 10 weight percent of acrylamide or of methacrylamide; (d) from 0.05 to 3 weight percent of a crosslinking comonomer having at least two polymerizable double bonds; (e) up to 5 weight percent of an unsaturated carboxylic acid; and (f) up to 20 weight percent of one or more further monomers, as well as fibrous articles reinforced with such a resin dispersion and showing reduced loss of resin binder on dry cleaning and reduced absorption of plasticizers, and methods of making such articles.

Abstract: Coating materials for pharmaceutical dosage forms contain, besides the conventional liquid or solid additives for pharmaceutical coatings, a binder comprising a synthetic polymer, prepared by emulsion polymerization, having 5 to 100% by weight of units derived from monomers of the formula ##STR1## wherein R.sub.1 is a hydrogen atom or a lower alkyl group, R.sub.2 is an alkylene or aralkylene group having at least 3 carbon atoms in the chain between the amino nitrogen and the ester oxygen atom of which at least one is tertiary or quaternary, and R.sub.3 and R.sub.4 are lower alkyl radicals or together with the amino-nitrogen atom form a heteroaliphatic ring, and, optionally, additional comonomer units.

Abstract: What are disclosed are a method for making an emulsion polymer by polymerizing water insoluble free-radically polymerizable monomers, or monomer mixtures predominantly comprising such monomers, by emulsion polymerization in the presence of a polymerization initiator which is soluble in organic solvents and has at least limited solubility in water, and in the further presence of a free non-polymerizable emulsifying acid, also soluble in organic solvents, and the conversion of such an emulsion polymer by spray drying into a polymer powder which is completely soluble in organic solvents to form clear solutions from which polymer films of reduced water sensitivity can be formed.

Abstract: What are disclosed are methods for making an aqueous dispersion of a synthetic resin copolymer, said dispersion having high pigment binding capacity and adaptable to use in the preparation of printing inks or pastes, said copolymer comprising a predominant amount of water insoluble monomers together with from 3 to 8 percent by weight of an acid component which is a water soluble acid or salt, which method comprises gradually adding said water insoluble monomers, together with a portion of said acid component, to an aqueous medium containing the balance of the acid component in the form of a dissolved water soluble salt; aqueous synthetic resin dispersions made by these methods; and printing inks comprising such an aqueous synthetic resin dispersion which has been neutralized and combined with such an amount of an organic solvent as converts the dispersion into a solution or colloidal dispersion of the synthetic resin.

Abstract: What is disclosed are a method for treating pelts or leather in the beamhouse, for tanning, or as an aftertreatment, which method comprises contacting said pelts or leather with an aqueous solution or dispersion of a copolymer comprising monomers of a nitrogenous ester of acrylic acid or of methacrylic acid, a further different ester of acrylic acid or of methacrylic acid, and acrylic acid or methacrylic acid, whereby portions of said copolymer are deposited in the grain layer without formation of a superficial film, and pelts and leather treated by this method.