Abstract: This invention relates to aqueous "multi-pack" coating compositions, that is, those which comprise at least two discrete components (or "packs") which are mixed prior to application.Prior attempts to provide an aqueous multi-pack composition have failed to provide a suitable combination of the desirable characteristics of adequate "pot-life" (the time for which the mixed components remain workable) and early development of adequate mechanical properties.The compositions of the present invention which provide such a combination consist of a number of components which together comprise a constituent having epoxide groups, a constituent comprising addition polymer in the form of an aqueous dispersion and a constituent capable of reacting with epoxide groups. In an especially preferred embodiment, the aqueous addition polymer dispersion is combined with at least one of the other constituets in the form of a multi-polymer particle dispersion.

Abstract: A crosslinkable coating composition is described which is miscible in all proportions with water and consists of crosslinked water-insoluble polymer microparticles sterically stabilised in dispersion in a liquid blend of a water-soluble crosslinking agent and a water-soluble, non-volatile substance of molecular weight less than 1000 which can take part in the crosslinking reaction but does not dissolve or swell the polymer, the amounts of the crosslinking agent and of the water-soluble non-volatile substance being up to 30% and 40% respectively of the total weight of film-forming material.

Abstract: Sterically stabilized aqueous polymer dispersions of at least 20% solids content are made by free radical-initiated polymerization of monomers in an aqueous medium at a temperature at least 10.degree. C. higher than the glass transition temperature of the polymer to be formed, in the presence of a compound which is soluble in the aqueous medium and contains in the molecule a polymeric component of molecular weight at least 1000 which is solvatable by the aqueous medium and an unsaturated grouping which can copolymerize with the monomers, the conditions being such that there is at no time present a separate monomer phase. The dispersions are useful as a basis of improved coating compositions.

Abstract: This invention relates to a novel product, fibrils of crosslinked polyester resin having a vesiculated structure, and to a process of making them.Vesiculated fibrils of crosslinked polyester resin of length 50 .mu.m-5 cm, diameter 1 .mu.m-2 mm and aspect ratio of 10-50 are prepared by pouring into water with stirring a selected solution in unsaturated monomer of a carboxylated unsaturated polyester resin of acid value 10-90 mg KOH per g., the water containing both a base having a pK.sub.b value of 8 maximum and a dispersion stabilizer, and initiating polymerization. The polyester solution is selected for suitability for fibril formation by means of a buoyancy test.The fibrils are useful in a number of applications, for example, as fillers for paints and putties, viscosity modifiers in liquids and replacements in some applications for fibrous mineral extenders such as asbestos.

Abstract: Dewatering aqueous polymer slurries containing polyvinylalcohol stabilizer by forming an insoluble organic destabilizer in situ from a soluble parent compound comprising ionizable groups. The slurry may then be filtered at 50.degree. C. or higher to yield a soft cake of beads essentially free of stabilizer.

Abstract: A process of preparing vesiculated polyester resin granules in which self-stabilizing and self-vesiculating disperse particles of an unsaturated polyester resin, wherein the polyester contains 2-50% of poly(ethylene oxide) of average molecular weight 1,000 to 10,000, are polymerized in an aqueous medium to polymeric vesiculated granules. The aqueous slurry of granules may be dried to a soft powder. These granules are useful as a component in paint.

Abstract: The invention relates to vesiculated polymer granules having a plurality of discrete internal vesicles whose walls are provided by said polymer, said granules having a mean diameter of 1-500 micron, the vesules having a maximum diameter of 20 micron and containing particulate solids at a concentration not exceeding 60% of the vesicle volume.