Polymeric compositions and methods of using them
AssigneeAllied Colloids Limited
InventorsBrian Dymond, John Langley, Malcolm Hawe
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Abstract
Water-immiscible liquids, for example oil-based drilling fluids, are thickened by the addition of an aqueous dispersion of polymeric particles that are water-insoluble, and insoluble but swellable polymer, in the water immiscible liquid. The particles have a unswollen average diameter of less than 10 .mu.m and at least 30% by weight are preferably in the range 0.5 to 5 .mu.m. Preferred polymers are formed from more than 80% by weight hydrophobic monomers, preferably alkyl (meth) acrylates, and up to 20% hydrophilic monomers, preferably unsaturated carboxylic acids, preferably acrylic acid.
Claims28
A water-immiscible liquid thickened by water insoluble polymer particles having a dry weight average particle size of below 10 .mu.m and that are insoluble in the water-immiscible liquid but are swollen by the liquid and that comprise a polymer which has a glass transition temperature of less than about 25.degree. C. and formed from monomers of which 80-100% are hydrophobic and 0-20% are hydrophilic, in which at least 25% of the monomers are both polar and hydrophobic and in which not more than 30% of the monomers are hydrophobic aromatic hydrocarbon monomers, all percentages being by weight of total monomer.
A water-immiscible liquid thickened by water insoluble polymer particles having a dry weight average particle size of below 10 .mu.m and that are insoluble in the water-immiscible liquid but are swollen to 4 to 50 times their dry volume by the liquid, and that comprises a polymer which has a glass transition temperature of less than about 25.degree. C., said polymer particles having been made by emulsion polymerisation of from 80 to 100% C.sub.1-30 alkyl (meth)acrylate monomers of which 50 to 100% are hydrophobic C.sub.6-18 alkyl (meth)acrylate monomers and 0 to 20% are hydrophilic monomers, in which at least 25% of the monomers are both polar and hydrophobic, and in which not more than 30% of the monomers are hydrophobic aromatic hydrocarbon monomers, all percentages being by weight of total monomer, and said liquid having been formed by adding to the water-immiscible liquid the resultant aqueous emulsion of the polymer particles.
Dependencies are inferred from the claim text.