Abstract: An aqueous dispersion of pigmented opacifying polymer particles, the particles comprising: i. an inorganic core comprising dispersed inorganic pigment particle and a dispersant ii. a first layer of base-swellable polymer comprising acid groups encapsulating the core iii. a second layer of non-base-swellable polymer encapsulating the first layer wherein the dispersant comprises or consists of hydroxyl moieties; and carboxyl groups derived from itaconic acid.

Abstract: A method of preparing an aqueous dispersion of opacifying polymer particles containing inorganic pigment particles therein is disclosed. The method yields hollow polymer particles containing pigment particles therein using a non-RAFT emulsion polymerization process by free radical polymerization. The technique is much faster and simpler than known RAFT methods.

Abstract: An aqueous dispersion of pigmented opacifying polymer particles, the particles comprising: i. an inorganic core comprising dispersed inorganic pigment particle and a dispersant ii. a first layer of base-swellable polymer comprising acid groups encapsulating the core iii. a second layer of non-base-swellable polymer encapsulating the first layer wherein the dispersant comprises or consists of hydroxyl moieties; and carboxyl groups derived from itaconic acid.

Abstract: A method of preparing an aqueous dispersion of opacifying polymer particles containing inorganic pigment particles therein comprising or consisting of the steps of: i. dispersing inorganic pigment in aqueous medium using a dispersant of acid value at least 65 mg KOH/g of dispersant, the dispersant comprising acid moieties and the pH during dispersion is greater than the pKa of the acid moieties and also at least 0.25 pH units above or below the iso-electric point of the pigment particles, to form a stable aqueous dispersion of the pigment in the aqueous medium ii. adjusting the pH of the pigment dispersion to below the pKa of the acid moieties comprising the base swellable polymer of step iii. whilst satisfying the pH criteria of step i. iii. forming a first layer of a base swellable polymer on the pigment particles by polymerising monomers comprising acid moieties iv. forming a second layer of non-base swellable polymer v.

Abstract: An aqueous coating composition having a PVC of from 70 to 80% comprising, based on the total volume solids of the dry coating unless otherwise stated, a) opacifying pigment particles comprising i) from 4 to 10% titanium dioxide ii) from 0 to 20% of hollow polymeric particles b) non-opacifying extender particles comprising i) calcium magnesium carbonate and/or ii) calcium carbonate and/or iii) nepheline syenite and/or iv) kaolin wherein i)+ii)+iii)+iv)=40 to 75% (to be announced by Katy) and iv) is 0 to 45% c) styrene-acrylic polymer binder particles having a calculated Fox Tg of from ?30 to 5° C. having an acid value of from 15 to 65 mg KOH/g of polymer and wherein the polymer particles are derived from acrylic monomers and optionally further comprising styrene and/or its derivatives d) dispersant which is insoluble in water at pH 3 wherein the composition is free of volatile organic solvent.

Abstract: An aqueous coating composition having a PVC of from 78 to 88% comprising, based on the total volume solids of the dry coating unless otherwise stated: a) opacifying pigment particles comprising i) from 3 to 10% titanium dioxide, ii) from 0 to 20% of hollow polymeric particles; b) non-opacifying extender particles comprising i) calcium magnesium carbonate, and/or ii) calcium carbonate, and/or iii) nepheline syenite, and/or iv) kaolin, wherein i)+ii)+iii)+iv)=40 to 80%, and iv) is 0 to 20%; c) polymer binder particles of calculated Fox Tg of from 25 to 70° C. having an acid value of from 15 to 65 mg KOH/g of polymer and wherein the polymer particles are derived from acrylic monomers and optionally further comprising styrene and/or its derivatives; d) dispersant having a weight average molecular weight of at least 3500 Daltons; e) fugitive coalescing solvent; wherein the composition is free of non-fugitive coalescing solvent.

Abstract: Aqueous coating composition having a PVC from 78 to 85% and free of non-fugitive coalescing solvent, comprising, based on the total volume solids of the dry coating unless otherwise stated, a) opacifying pigment particles comprising from 3 to 10% titanium dioxide and from 0 to 20% of hollow polymeric particles; b) non-opacifying extender particles comprising calcium magnesium carbonate and/or calcium carbonate and/or nepheline syenite and/or kaolin; c) polymer binder particles of calculated Fox Tg of from 5 to 25° C. having an acid value of from 15 to 65 mg KOH/g of polymer; d) dispersant having weight average molecular weight of at least 3500 Daltons, and wherein the dispersant demand of a mixture of the opacifying pigment particles, other than the hollow polymeric particles, of a) and the extender particles of b) is greater than 0.35 wt %, calculated on the weight of the titanium dioxide and extender particles; e) fugitive coalescing solvent.

Abstract: Aqueous coating composition having a PVC from 78 to 85% and free of non-fugitive coalescing solvent, comprising, based on the total volume solids of the dry coating unless otherwise stated, a) opacifying pigment particles comprising from 3 to 10% titanium dioxide and from 0 to 20% of hollow polymeric particles; b) non-opacifying extender particles comprising calcium magnesium carbonate and/or calcium carbonate and/or nepheline syenite and/or kaolin; c) polymer binder particles of calculated Fox Tg of from 5 to 25° C. having an acid value of from 15 to 65 mg KOH/g of polymer; d) dispersant having weight average molecular weight of at least 3500 Daltons, and wherein the dispersant demand of a mixture of the opacifying pigment particles, other than the hollow polymeric particles, of a) and the extender particles of b) is greater than 0.35 wt %, calculated on the weight of the titanium dioxide and extender particles; e) fugitive coalescing solvent.

Abstract: An aqueous coating composition having a PVC of from 78 to 88% comprising, based on the total volume solids of the dry coating unless otherwise stated: a) opacifying pigment particles comprising i) from 3 to 10% titanium dioxide, ii) from 0 to 20% of hollow polymeric particles; b) non-opacifying extender particles comprising i) calcium magnesium carbonate, and/or ii) calcium carbonate, and/or iii) nepheline syenite, and/or iv) kaolin, wherein i)+ii)+iii)+iv)=40 to 80%, and iv) is 0 to 20%; c) polymer binder particles of calculated Fox Tg of from 25 to 70° C. having an acid value of from 15 to 65 mg KOH/g of polymer and wherein the polymer particles are derived from acrylic monomers and optionally further comprising styrene and/or its derivatives; d) dispersant having a weight average molecular weight of at least 3500 Daltons; e) fugitive coalescing solvent; wherein the composition is free of non-fugitive coalescing solvent.

Abstract: An environmentally friendly stable aqueous optionally structured water-resistant architectural coating composition (especially a paint) containing a film-forming binder polymer composed of a starch modified by the presence of carboxylic acid or inorganic carboxylate groups and bonded (probably grafted) to chains of copolymerized mono-ethylenically unsaturated monomers (e.g. “acrylic”, “vinyl” or “styrenic” copolymers) permitting a stable aqueous dispersion of the binder polymer to be made which retains good water-resistance in the dried paint. The modified starch allows paints to be made with less dependence on materials obtained from non-renewable resources whilst retaining a low water-sensitivity.

Abstract: An environmentally friendly stable aqueous optionally structured water-resistant architectural coating composition (especially a paint) containing a film-forming binder polymer composed of a starch modified by the presence of carboxylic acid or inorganic carboxylate groups and bonded (probably grafted) to chains of copolymerized mono-ethylenically unsaturated monomers (e.g. “acrylic”, “vinyl” or “styrenic” copolymers) permitting a stable aqueous dispersion of the binder polymer to be made which retains good water-resistance in the dried paint. The modified starch allows paints to be made with less dependence on materials obtained from non-renewable resources whilst retaining a low water-sensitivity.

Abstract: An environmentally friendly stable aqueous optionally structured water-resistant architectural coating composition (especially a paint) containing a film-forming binder polymer composed of a starch modified by the presence of carboxylic acid or inorganic carboxylate groups and bonded (probably grafted) to chains of copolymerized mono-ethylenically unsaturated monomers (e.g. “acrylic”, “vinyl” or “styrenic” copolymers) permitting a stable aqueous dispersion of the binder polymer to be made which retains good water-resistance in the dried paint. The modified starch allows paints to be made with less dependence on materials obtained from non-renewable resources while retaining a low water-sensitivity.