PROCESS FOR MAKING VESICULATED POLYMER AND COATINGS MADE THEREFROM

摘要

1329985 Vesiculated polymers DULUX AUSTRALIA Ltd 1 Dec 1970 [1 Dec 1969] 57060/70 Headings C3C and C3R A vesiculated polymer is made by converting to a solid polymer a liquid medium in which is dispersed particles of another polymer insoluble in the liquid medium and swollen by a liquid swellant, the liquid swellant then being at least partially removed from the disperse polymer particles. The liquid medium may be a solution of a polymer in a solvent, the solvent being removed to effect solidification, or a polymerizable monomer. Particles of the other polymer, the diameters of which are smaller than the required vesicle size, may be dispersed in the liquid medium, liquid swellant for the polymer then being added to the dispersion until the size of the dispersed particles which imbibe the swellant increases to the required vesicle size. In a preferred method, the dispersion of polymer particles in the liquid medium is itself dispersed in a suspending liquid, suitably water or an aqueous liquid in which the liquid is insoluble. Particles of the polymer to be dispersed in the liquid medium may be pre-formed and dispersed in the liquid medium in the presence of a stabilizer. The particles may be formed by dispersion polymerization of monomer in an organic liquid in which the monomer is soluble and the resulting polymer is insoluble, the liquid containing a stabilizer for the polymer particles. Examples I, II, III and V illustrate the preparation of vesiculated granules of poly- (styrene/divinyl benzene) by an emulsification process using an aqueous swellant and suspending liquid. Examples XV to XVII are modifications of the method of Example V. Example IV is similar but the vesicles comprise a proportion of pigment particles. Examples VI to X describe respectively the preparation of vesiculated granules of (i) poly-(methyl methacrylate/ divinyl benzene), (ii) poly-(styrene/divinyl benzene), (iii) cross-linked polyester granules, (iv) urea formaldehyde polymer, (v) casein/formaldehyde polymer. Examples XI and XII relate to the preparation respectively of (i) matt aqueous latex paints, and (ii) non-aqueous paints, comprising the vesiculated granules of the invention. Example XIII illustrates the preparation of a vesiculated polystyrene moulding, and Example XIV that of a vesiculated polymer coating film as a substrate. Examples XV and XVI are modifications of Example V.