Casionic saructured-particle laser and dispersion

1533174 Cationic polymer dispersions DOW CHEMICAL CO 21 April 1976 [21 April 1975 (2)] 16117/76 Headings C3L and C3P Aqueous colloidal dispersions of cationic structured particles of polymer consisting of a non-ionic organic polymer core encapsulated by a thin layer of water-insoluble organic copolymer of (a) an unsaturated non-ionic monomer free from activated halogen and (b) an unsaturated nonionic activated halogen-containing monomer, and having pH indpendent cationic groups chemically bound to the copolymer at or near the particle surface, may be prepared by reacting a latex of copolymer particles having activated halogen bound to a thin layer of the copolymer at or near the particle surface with a water-stable non-ionic nucleophile capable of diffusing through aqueous media whereby pH independent cationic groups are chemically bound to the particles at or near the particle surface. The active halogen containing polymer may be derived from unsaturated benzylic chlorides and bromides and unsaturated aliphatic bromides and iodides. The nucleophile may be a monobasic aromatic amine, tetraalkyl thiourea, t-amine or t-phosphine. Sulphonium groups may be oxidized, e.g. with hydrogen peroxide to sulphoxonium groups. Examples describe the reaction of dispersions of structured particles of copolymers of ethyl acrylate/methyl methacrylate/vinyl benzyl chloride (VBC), butadiene / styrene / butyl acrylate / VBC, butadiene / styrene / hydroxyethyl acrylate / VBC, styrene / butadiene/ VBC, styrene / butyl acrylate / 2 - bromoethyl methacrylate, styrene / butyl acrylate / 2 - chloromethylbutadiene and methyl methacrylate / butyl acrylate / vinyl bromide with trimethylamine, triethylamine, pyridine, tetramethylthiourea, dimethyl sulphide, ethylthioethanol and triphenylphosphine, and (XXIII) oxidation of sulphonium groups to sulphoxonium with hydrogen peroxide. The dispersions may be used for coating.