Imperial Chemical Industries Limited

Alan J Backhouse

Stephen J Thorne

Morice W Thompson

Charles W Bromley

Malcolm S Andrew

Auguste L Palluel

Andrew Frangou

Patrick A Hunt

A polyisocyanate mixture which is emulsifiable in water comprising;

Polyisocyanate mixture

The tendency of metallic pigments, especially of aluminum flake pigments, to react with the aqueous medium of a water-born paint composition with the generation of gaseous material is prevented or reduced by incorporating in the composition an agent containing in the molecule at least one P--OH group, or a salt derivative thereof, which is obtained by reacting a compound containing the grouping --O--PO(OH.sub.2) with one or more epoxide group-containing compounds at least one of which also contains at least one aromatic or alicyclic group.

Water-born coating compositions comprising metallic powder or flake

For use in a process for producing a multi-layer coating upon a substrate surface, in which there is first applied to the surface a pigmented basecoat composition and there is then applied to the basecoat film a transparent topcoat composition, a pigmented basecoat composition which is based upon a dispersion in an aqueous medium of crosslinked polymer microparticles which have a diameter of 0.01-10 microns, are insoluble in the aqueous medium and are stable towards gross flocculation, the dispersion having a pseudoplastic or thixotropic character.

Pigmented basecoat composition

The production is described of a dispersion of polymer microparticles, which may optionally be crosslinked, by dispersion polymerisation in aliphatic hydrocarbon liquid under specified conditions of a monomer mixture which comprises up to 50% of styrene or a substituted derivative thereof and up to 50% by weight of a derivative of maleic acid or fumaric acid which is soluble in the hydrocarbon liquid at the polymerization temperature. The microparticles have a size in the range 100-400 nm and a high refractive index, and are suitable for incorporation in coating compositions which are based on a film-forming polymer, such as a thermosetting acrylic resin or an alkyd resin, containing a significant proportion of aromatic residues, and which are intended to be used either unpigmented or when containing only light-absorbing pigments.

Production of polymer microparticles and coating compositions containing

A process is described for making sterically stabilized non-aqueous dispersions of composite polymer microparticles, in which (1) monomers including at least one crosslinking monomer are polymerized in an aqueous medium at a temperature at least 10.degree. higher than the glass transition temperature of the polymer to be formed, in the presence of a block or graft copolymer stabilizing agent, under conditions such that there is at no time present a separate monomer phase, (2) further monomers, not including any crosslinking monomer, are polymerized in the dispersion thus obtained, the presence of a separate monomer phase again being avoided, and (3) the microparticles are transferred from the resulting dispersion into a non-aqueous medium which is a solvent for the non-crosslinked polymer generated in (2). The microparticles are of value for incorporation into coating compositions the main film-forming constituent of which is compatible with the non-crosslinked component of the particles.

Polymerization process

A process for producing a multi-layer coating upon a substrate surface, in which there is first applied to the surface a pigmented basecoat composition and then there is applied to the basecoat film a transparent topcoat composition; characterized in that the basecoat composition is based upon a dispersion in an aqueous medium of crosslinked polymer microparticles which have a diameter of 0.01-10 microns, are insoluble in the aqueous medium and are stable towards gross flocculation, the dispersion having a pseudoplastic or thixotropic character.

Article having basecoat/clearcoat and process for coating

Crosslinked addition polymer microparticles are produced by dispersion polymerization of monomers in an aliphatic hydrocarbon liquid in the presence of a dispersion stabilizer and also of a specified type of amino resin which is insoluble in the hydrocarbon liquid, at least one of the monomers polymerized carrying a group which can react with the amino resin under the conditions of polymerization. Coating compositions having improved application characteristics and/or giving improved film properties are obtained by dispersing the microparticles in combinations of suitable film-forming polymers and diluents.

Improved application characteristics of spray-applied coatings, particularly for automobile bodies, are obtained when the composition applied comprises (A) a film-forming polyester or alkyd resin, (B) a volatile liquid solvent for the resin and (C) polymer microparticles which are stably dispersed in the solution of the resin in the solvent. Improvements observed include increased resistance to 'sagging.'

Coating process

A process for coating a substrate, especially an automobile body, by spray application whereby improved resistance to 'sagging' or 'running' on application can be obtained without reduction of the thickness of film which is applied; the process is characterized by the use of a coating composition comprising a film-forming acrylic resin, a volatile organic liquid diluent, a pigment other than a metallic flake pigment, and specified polymer microparticles which are stably dispersed in the combination of the resin and the diluent.

Spray coating of acrylic resin comprising polymeric microparticles

A multilayer coating is produced by applying to a substrate as a base-coat composition a pigmented solution in a volatile organic liquid of a film-forming polymer, the solution also containing specified polymer microparticles, forming a polymer film from the base-coat composition, then applying to the film so obtained a transparent top-coat composition and finally forming a second polymer film upon the base-coat film.

Coating composition for spray application to a substrate comprising a film-forming polymer, a volatile organic liquid diluent, specified polymer microparticles stably dispersed in the combination of the film-forming polymer and the diluent, and metallic pigmentation also dispersed in the said combination. The composition affords improved control of the orientation of the metallic pigment.

Growing community of inventors

South Ascot, United Kingdom

Alan J Backhouse