Abstract: Powders of an emulsion polymer having reduced fines and exhibiting low dusting are made by spray drying an emulsion of a polymer having a Vicat softening temperature above 60.degree. C., said emulsion containing an external plasticizer having a boiling point of at least 150.degree. C.

Abstract: Polymer powders comprising aggregated polymer particles, said powders having a low content of fines and being suitable as processing aids in the manufacture of polyvinyl chloride, are made by spray drying an aqueous dispersion (latex) of two emulsion polymers, one of which has a dynamic glass transition temperature above 90.degree. C. and the other of which has a dynamic glass transition below 105.degree. C., the latter being at least 10 K. degrees below the former.

Abstract: The formation of interfering polymer deposits in spary drying apparatus during the spray drying of aqueous dispersions or solutions of polymers in a stream of warm air is avoided if water is atomized together with the dispersion or solution.

Abstract: A method for obtaining redispersible powders of a copolymer having a dynamic glass transition temperature, T.sub.max, below 150.degree. C., by spray drying an aqueous dispersion thereof having a minimum film forming temperature, MFT, using an inlet temperature T.sub.i and an outlet temperature T.sub.o such that MFT<T.sub.i <T.sub.max and MFT<T.sub.o <65.degree. C.

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: What are disclosed are plastisols of copolymers of methyl methacrylate with from 0.1 to 10 weight percent of itaconic acid or of itaconic acid anhydride, which copolymers have a glass transition temperature above 50.degree. C., a degree of polymerization higher than 400 and an average particle size ranging from 0.1 to 500 microns and contain, per 100 parts by weight of the copolymer, from 100 to 1000 parts by weight of an organic plasticizer compatible with the copolymer, and optional fillers and further conventional additives.

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: 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: 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: 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: A storage-stable plastisol is disclosed comprising an organic plasticizer and particles of a methyl methacrylate copolymer, said particles comprising a core portion of a polymer compatible with said plasticizer and a surrounding shell portion of a polymer incompatible with the plasticizer.

Abstract: Powders of physiologically-tolerable copolymers of vinyl and vinylidene monomers, said copolymers being useful as fast-dissolving resin binders for the preparation of pharmaceutical coatings, having a residual monomer content of less than 0.05 percent by weight, and having a primary particle size less than one micron; a method of preparing such powders by spray drying an aqueous dispersion of a copolymer under non-sintering temperature conditions; a method for preparing solutions for coating orally-ingestible dosage unit forms with said copolymers; and such dosage unit forms coated with said copolymers.

Abstract: A powdery copolymer having a powder particle size from 0.1 to 200 microns, said copolymer comprising at least 50 percent by weight of methyl methacrylate and 0.2 to 10 percent by weight of at least one monomer having a basic nitrogen atom, the balance, if any, being other monomers copolymerizable therewith, said copolymer being prepared by emulsion copolymerization such that all or a predominant portion of the monomer or monomers having a basic nitrogen atom is first added to the remaining monomers after the polymerization of at least half of said remaining monomers, the resulting copolymer then being recovered from the resultant latex in powder form.