Imperial Chemical Industries Limited

Trevor Stephen Sayer

Jonathan A Graystone

Michael A Simpson

Jennifer Ruth Coutts

For paints and the like, an aqueous tinter which does not block dispensing nozzles and which has a viscosity of from 0.05 to 1.5 Ns/m.sup.2 (20.degree. C.) and which contains pigment particles, water, micellising dispersant and a non-micellising auxiliary material. The weight ratio of dispersant to pigment must exceed the ratio which would be present at the Daniel Flow Point for a notional tinter consisting only of the pigment, water and the dispersant. The amount of auxiliary material must be sufficient to enable the tinter to be expelled through a bore 2 mm in diameter and 15 mm long by a pressure of not more than 320 MN/m.sup.2 after storage in the bore at 25.degree. C. for 18 hours under a relative humidity of 50%. Preferred dispersants comprise long chain hydrophilic and long chain hydrophobic moieties which may be poly(alkylene glycol) esters of long chain fatty acids or hydrophobic backbone copolymers with pendant poly(alkylene glycol) moieties as hydrophilic side chains.

Aqueous non-blocking tinter for paints

An amphipathic co-polymer having a weight average molecular weight of from 2,500 to 20,000 inclusive and comprising an addition polymer backbone and at least one C.sub.1-4 alkoxy polyethylene or polyethylene copropylene glycol acrylate or methacrylate stabilizer unit where the backbone comprises up to 30% by weight of non-functional structural units and at least 70% by weight in total of stabilizer units and functional units where the functional units are optionally substituted styrene-containing units, hydroxy group-containing units and carboxyl group containing units, such that the proportions of hydroxy groups to carboxyl groups to styrene groups to propylene-oxy or ethylene-oxy groups are respectively 1 : 0.10-26.1; 0.28-25.0; 0.80-66.1.

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Woosehill, United Kingdom

Trevor Stephen Sayer