Imperial Chemical Industries Limited

John Bentley

Morice W Thompson

Auguste L Palluel

Thomas Whitehead Stafford

Brian Robert Letchford

Coating compositions are described in which the film-forming material consists of (a) 30-85% by volume of disperse particles of size 0.01-20 microns, of which not less than 50% by volume are non-crosslinked polyester microparticles, and (b) 70-15% by volume of a liquid continuous phase of viscosity 0.1-20 poise which is curable to a film-forming polymer by means of an autoxidative (i.e. air-drying) mechanism, the particles (a) being stably dispersed in the liquid (b) in a deflocculated state by means of an amphipathic steric stabilizing agent; the liquid continuous phase is composed of an autoxidizable derivative, such as a drying-oil fatty acid ester of a polyol in conjunction with a coreactive liquid such as an acrylic or methacrylic ester of a higher alcohol or a polyol.

Coating compositions

A coating composition is provided in which the film-forming material consists of (a) 30-85% by volume of disperse phase particles of size 0.01-20 microns, of which not less than 50% are polymer microparticles, stably dispersed in (b) 70-15% by volume of a liquid continuous phase which is capable of curing by a condensation polymerization reaction, the total volume of components (a) and (b) being 100% and the disperse phase being capable of taking part in the curing reaction. The composition can have a very high solids content and makes possible the production of thick films free from surface shrinkage.

A dispersion of a condensation polymer in an organic liquid medium in which the polymer is insoluble is prepared by heating in the liquid medium one or more appropriate reactants one of which is present in the liquid disperse phase of an emulsion of which the continuous phase is constituted by the said liquid medium, in the presence dissolved in the liquid medium of a single-chain polymeric material of molecular weight between 1000 and 20,000 which carries at least one reactive group capable of taking part in the condensation polymer-forming reaction.

Process for the preparation of polymer dispersions

Coating compositions are described in which the film-forming material consists of (a) 30-85% by volume of disperse particles of size 0.01-20 microns, of which not less than 50% by volume are cross-linked polymer microparticles, and (b) 70-15% by volume of a liquid continuous phase of viscosity 0.1-20 poise which is curable to a film-forming polymer by means of an autoxidative (i.e. air-drying) mechanism, the particles (a) being stably dispersed in the liquid (b) in a deflocculated state by means of an amphipathic steric stabilizing agent. Typically, the polymer microparticles may be composed of a cross-linked polyester and the liquid continuous phase of a drying-oil fatty acid ester of a polyol, optionally in conjunction with a coreactive liquid such as an acrylic or methacrylic ester of a higher alcohol or a polyol.

Autoxidizable coating compositions

A process for manufacturing a stable dispersion in an organic liquid of particles consisting of (a) a polymer insoluble in the liquid and formed by polymerization of monomer(s) at least one of which is solid at the polymerization temperature and (b) sub-particles of a solid modifying agent for the polymer, the process comprising dispersing the solid monomer and the modifying agent together in the liquid in the presence of a specified dispersing agent so as to form a stable dispersion of solid particles not larger than 50.mu., and heating the dispersion together with any other monomers required, so as to bring about polymerization, in the presence of a specified stabilizing agent for the polymer formed. The functions of dispersing agent and stabilizing agent may be combined in a single substance.

Stable dispersions of polymer particles containing sub-particles of a

A process is described for the production of a stable dispersion of a copolymer, in particular of a copolyester, copolyamide or copolyesteramide, in a non-solvent organic liquid. The process involves the steps of (1) dispersing two or more comonomers, each of which is capable of undergoing homopolymerization and is solid at the copolymerization temperature, in the liquid with the aid of a defined monomer-stabilizing agent and so as to produce monomer particles no larger than 50.mu., and (2) heating the dispersion so obtained so as to bring about copolymerization, in the presence of a defined polymer-stabilizing agent. The copolymers so produced are believed to be different in structure from those obtained from the same comonomers by melt or solution copolymerization.

Polymer dispersions

A flexible sheet material provided with a flexible coating of an organic material which is curable on exposure to actinic light to produce a less flexible coating on the sheet. The coated sheet is rolled up for storage in the absence of actinic light such that when the sheet is unrolled and attached to a wall or other surface so exposing the coating to actinic light, a less flexible coating on the sheet results.

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Maidenhead, United Kingdom

John Bentley