Abstract: There is provided an improved method for particle size and distribution determinations using a photosedimentometer having a centrifugal disc chamber for containing a spin fluid. The spin fluid must be characterized by a density gradient. The present process provides a novel way of composing the spin fluid. The less dense component water/alcohol is introduced first, and the more dense component (e.g., water) is introduced second. At no time is the power to the motor driving the disc interrupted as in prior art methods. Better and more reproducible results are secured.

Abstract: The blocked isocyanate crosslinker commonly used in conventional electrocoat compositions are difficult to incorporate satisfactorily into latex paint compositions for such application. An improved homogenized feed process for incorporating such water insoluble crosslinking agents into the latex particle during emulsion polymerization of reactive (hydroxy functional) vinyl monomers provides thermosetting latex of high cleanliness. The invention pertains to an improved cationic, amine-stabilized electrocoating composition and process.

Abstract: New siloxane-esters, useful as powder coating resins, are prepared by random condensation polymerization of a hindered glycol and a hydroxy functional silicone having about two ##STR1## groups per molecule wherein R is lower alkyl or phenyl groups and the remaining silicone valences form ring-structured siloxanes. Improved powder properties, including tack temperatures of 150.degree. F. to 220.degree. F., are believed to result in part from the hindered glycols especially those having carboxylic functionality.

Abstract: Clear topcoats for grain printed, paper overlay and wet print interior wood paneling comprising a low Tg acrylic latex emulsion polymer, a high Tg non-film forming plastic pigment latex emulsion and a glycoluril crosslinker in a solids ratio of 1:6 parts latex to 1 part crosslinker provide coatings of excellent block resistance and gloss retention adapted to cure at temperatures of from about 100.degree. F. to 260.degree. F.

Abstract: Polymer composition particularly useful as protective surface coatings comprise an aqueous mixture of epoxy-acrylic graft copolymers combined with a functional low molecular weight polyester and minor amounts of an amine derivative crosslinking resin. The low molecular weight polyester contains reactive hydroxyl or carboxyl functional groups and a molecular weight less than about 2,000.

Abstract: New Cobalt(II) nitrilomethylidyne dipyrrole complexes such as Cobalt(II) 2,2'-[trimethylenebis(nitrilomethylidyne)]-dipyrrole, Cobalt(II) 2,2'-[o-phenylenebis(nitrilomethylidyne)]-dipyrrole and their basic ligand complexes are effective catalysts for molecular weight control in acrylate/methacrylate polymerization.The process comprises polymerizing monomers, especially including methacrylic monomer or methacrylic/acrylic monomer, in the presence of azo initiator and between 0.0001% and 0.01% of Cobalt(II) 2,2'-[trimethylenebis(nitrilomethylidyne)]-dipyrrole and/or Cobalt(II) 2,2'-[o-phenylenebis(nitrilomethylidyne)]-dipyrrole complexes to produce low molecular weight acrylate polymers and copolymers.