Back to results
US 5,171,781 AGranted
Polymeric compositions
AssigneeAllied Colloids Limited
InventorsDavid Farrar, John R. Field, Peter Flesher
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeAllied Colloids Limited
InventorsDavid Farrar, John R. Field, Peter Flesher
Estimating the term…
Water absorbent particulate polymers and their uses are described. Friable aggregates may be made by bonding substantially dry polymer particles with an aqueous liquid and drying the aggregates. These aggregates can be broken down to the individual polymer particles upon mixing with an aqueous medium and thus can have the flow properties of relatively coarse particles and the performance properties of relatively fine particles. They may be soluble nd used as flocculants or viscosifiers or binders for, for instance, iron ore pelletisation. Alternatively they may be swellable and insoluble, for instance for converting a sticky particulate mass (such as coal fines filter cake) to a crumbly solid. When pellets are formed by compression moulding from a crumbly solid made by mixing water absorbent polymer particles with a sticky mass of inorganic particles (such as a coal fines filter cake) improved properties are obtained when the absorbent polymer particles are introduced in the form of a dispersion in water-immiscible liquid.
A particulate polymeric product comprising particles of a water soluble polymeric viscosifier or flocculant wherein the particles have a size of below 10 .mu.m and are present in the form of friable aggregates of which at least 90% have a size above 50 .mu.m and said aggregates having been made by bonding substantially dry polymer particles with an aqueous liquid and drying the aggregates and said aggregates being friable in that they can be broken down to the individual polymer particles by mixing with an aqueous medium that is to be thickened or flocculated, and wherein the soluble polymer particles are cross linked or branched and were made by polymerization of water soluble ethylenically unsaturated monomer or monomer blend.
A particulate polymeric product comprising particles of a water soluble polymeric flocculant wherein the particles have a size of below 10 .mu.m and are present in the form of friable aggregates of which at least 90% have a size above 50 .mu.m and said aggregates having been made by bonding substantially dry polymer particles with an aqueous liquid and drying the aggregates and said aggregates being friable in that they can be broken down to the individual polymer particles by mixing with an aqueous medium that is to be flocculated, and wherein the soluble polymer particles are cross linked or branched and were made by polymerization of water soluble ethylenically unsaturated monomer or monomer blend by gel or reverse phase polymerization.
Dependencies are inferred from the claim text.