Dispersing agents
AssigneeAllied Colloids Limited
InventorsMalcolm Hawe, David Farrar
Life of this patent
Estimating the term…
Abstract
A dispersing agent for particles in aqueous media comprises a copolymer formed from ethyleneically unsaturated monomers including a water-soluble monomer and a monomer carying a pendant group A.sub.m B.sub.n A.sub.p R in which B is ethyleneoxy and n is at least 2, m and p are each generally 0 and R is a hydrophobic group, generally a C.sub.12-18 alkyl group or alkaryl group. The polymers generally have molecular weights in the range 500-100,000. The dispersants are particularly useful for suspending hydrophobic particles in aqueous media, for example to produce coal slurries, or to suspend hydrophilic particles in aqueous media having high electrolyte concentrations, for example for producing paints and, particularly, drilling muds formed in sea water.
Claims10
A dispersion of hydrophobic particles in an aqueous medium containing a polymeric dispersing agent, wherein the viscosity of the dispersion is reduced by the presence of a thinning amount of dispersing agent and the dispersing agent is a water-soluble polymer comprising, by weight:
- (a) 30-99% of an ionic water-soluble ethylenically unsaturated monomer, which is free of polyalkylene oxide chains and of other substituents creating side chains of longer than 6 atoms chain length, and
- (b) 1-70% of an ethylenically unsaturated monomer that carries a pendant group --B.sub.n R wherein B is ethyleneoxy, n is an integer of at least 5, and R is a hydrocarbyl group containing 8 to 30 carbon atoms, the polymer having a molecular weight in the range 500-100000.
Dependencies are inferred from the claim text.