NON-BLOCKING OF DISPENSING NOZZLES BY AQUEOUS TINTERS

摘要

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/m2 (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 2mm in diameter and 15mm long by a pressure of not more than 320 MN/m 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.