Latex paint containing titanium dioxide pigment

Abstract

The present invention relates to latex paints, which contain a) a multistage carboxylated polymer latex binder obtainable by multistage aqueous emulsion polymerisation of a monomer composition M consisting of at least one non-ionic monomer M1, which is selected from C1-C20-alkyl esters of acrylic acid, C1-C20-alkylesters of methacrylic acid, and vinyl aromatic monomers; one or more monoethylenically unsaturated monomers M2, which are selected from monoethylenically unsaturated monocarboxylic acids having 3 to 6 carbon atoms and monoethylenically unsaturated dicarboxylic acids having 4 to 6 carbon atoms, and optionally one or more non-ionic monomers M3, which are different from monomers M1; where in at least one stage, the relative amount of monomers M2 added in this stage is at least 6% byweight, based on the total amount of monomers added in said stage, the total amount of monomers M2 being from 0.05 to 5% by weight, based on the total amount of the monomer composition M; b) a titanium dioxide pigment; and c) a polymeric dispersant PD which is selected from homo and copolymers of monomers M4, which are selected from monoethylenically unsaturated monocarboxylic acids having 3 to 6carbon atoms and monoethylenically unsaturated dicarboxylic acids having 4 to 6 carbon atoms, where the monomers M4 make up at least 85% of the monomers forming the polymeric dispersant and where thepolymeric dispersant PD has a number average molecular weight, as determined by GPC, of at most 5500 Dalton.

Description

[0001] The present invention relates to latex paint, it contains [0002] a) a multi-stage carboxylated polymer latex adhesive obtainable by multi-stage aqueous emulsion polymerization; [0003] b) titanium dioxide pigments; and [0004] c) Polymer dispersant PD. [0005] The invention also relates to a process for the preparation of such latex paints and to the use of said latex paints for coating surfaces, in particular for coating interior or exterior walls and ceilings. technical background [0006] Titanium dioxide (TiO 2 ) are often used as pigments in aqueous coating compositions, such as latex paints. In addition to whiteness, TiO 2 Also provides opacity or hiding power to paints. The opacity or hiding power of such a paint or lacquer is a measure of the paint's ability to hide the surface to which it is applied. [0007] The opacifying power is a function of the spacing between opacifying pigment particles in the dried applied paint (see US 6,080,802, EP 1398333...

AI Technical Summary

Problems solved by technology

[0017] Proposed prior art for improving TiO 2 Methods for hiding or opacifying efficacy of pigments are unsatisfactory because either the polymer dispersion requires expensive phosphorus-containing monomers to achieve acceptable hiding or opacifying efficacy and flocculation stability, or the formulation requires additional expensive dispersion agent or cumbersome preparation of TiO 2 Pigment / polymer pre-composite method

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