method for stabilising a dispersion using a polyelectrolyte, formed by ionogene non-ionic hydrophilic and hydrophobic units.randomly on the chain of the polyelectrolyte are divided.

摘要

A colloidal dispersion contains as the surfactant a stabilising amt. of a nonpolymerisable, linear, interpolymeric, interfacially spreading polyelectrolyte in both the disperse and continuous phase, where (1) the polyelectrolyte is a mixt. of nonionic hydrophobic and ionic hydrophilic units, (a) the nonionic hydrophobic units being copolymerised ethylenically unsatd. monomers which when in the form of amorphous homopolymers, are 0.1% soluble in water the monomer having no. substits. extending more than 10 angstroms from the point of ethylenic unsatn., and the units being randomly distributed in the backbone of the polyelectrolyte, and (b) the ionic hydrophilic units being copolymsd. ethylenically unsatd. ionic monomers which when in the form of amorphous homopolymers are soluble in water, the ionic hydrophilic units remaining completely ionised over the entire pH range 0-14; (2) the polyelectrolyte is adsorbed at the disperse phase in a flat configuration, the area occupied by each ionic hydrophilic unit of the polyelectrolyte at the disperse phase surface being 60-100 angstroms2 per hydrophilic unit; and (3) the polyelectrolyte has an adsorption constant =1 at the point where the disperse phase is satd. with the polyelectrolyte, the adsorption constant being determined by the amt. of polyelectrolyte in the disperse phase divided by the amt. of polyelectrolyte in the continuous phase. The dispersion is used as a coating compsn. and in the prepn. of microspheres and seed latexes.