Allied Colloids Limited

Peter Flesher

David Farrar

Adrian Swinburn Allen

John R Field

John G Langley

Malcolm Hawe

John B Clarke

Ian Michael Johnson

Kenneth Charles Symes

Malcolm Skinner

David Marshall

Gerald P Benn

Brian Dymond

Tony Whittaker

John Robinson

Norma Rosier

Ian M Moody

Peter R Lawrence

Alan C Benson

Ken C Symes

A water absorbing particulate polymer material wherein the polymer material when in dry powder form has a particle size of about 50 .mu.m to about 500 .mu.m and wherein the particles consist of internally bonded finer particles which finer particles have a size below 50 .mu.m. The process of using the water absorbing polymer, material to convert a wet sticky mass of inorganic particulate such as coal fines into a crumbly or flowable solid. A process using a water absorbing particulate polymer material to convert a wet sticky mass of organic particulate material into a crumbly or flowable solid wherein the organic matter can be, for example, food waste or sewage.

Water absorbing polymers

Methods of making crystalline-coated polymeric materials

High molecular weight polymer that can form a viscous aqueous solution is chemically modified by mixing the previously formed polymer (as a powder, reverse phase dispersion or oil-in-water emulsion) with water and the reagent for effecting the chemical modification so as to form a viscous aqueous mixture having a viscosity of at least 1OOO cps (Brookfield RVT) and then feeding this mixture as intermittent batches into one end of a tower through which it moves with substantially plug flow and from which it is withdrawn, at the end of the reaction, as intermittent batches. The apparatus for this purpose is also novel.

Process and apparatus for performing chemical reactions

A water absorbent water insoluble polymeric element, such as a fibre, film, coating, bonding layer or foam, is made by forming a substantially linear polymer by polymerisation of water soluble ethylenically unsaturated monomer blends comprising carboxylic and hydroxylic monomers and then reacting the carboxylic and hydroxylic monomers in the linear polymer to form internal cross links within the polymer.

Absorbent products and their manufacture

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.

Polymeric compositions

Particulate metal ore is pellitized by use of a novel polymeric binder that comprises aggregates of polymer particles and that have a size mainly above 100 .mu.m and the aggregates are disintegrated during the process.

Process for pelletizing particulate materials

Film or fibre is made from a polymer of water soluble ethylenically unsaturated monomeric material that includes ionic monomer by extrusion and stretching, and a counterionic lubricant compound is absorbed into the surface of the fibre or film before or during the stretching. The counterionic lubricant compound is also of use for providing a lubricated film on other extruded or comminuted elements of water swellable or water soluble polymeric material.

The invention provides a substantially dry particulate composition comprising a polyacrylamide and an amidase. An aqueous composition made by dispersing this into water will then have a satisfactorily low content of residual acrylamide even if the initial polymer was contaminated with monomer. The composition is made by blending dry polyacrylamide particles with the amidase.

Polymeric compositions and their production

The properties of absorptive synthetic polymer particles formed by polymerisation of water soluble monomers such as sodium acrylate or acrylamide with a cross linking agent are improved, especially as regards absorptive capacity for aqueous electrolytes, by copolymerising the monomers with an ethylenically unsaturated monomer that includes a pendant group --A.sub.m B.sub.n A.sub.p R where B is ethyleneoxy, n is at least 2, A is propyleneoxy or butyleneoxy, m and p are each less than n and are preferably zero, and R is a hydrophobic group.

Absorbent polymers, their manufacture and uses

A water absorbent water insoluble polymeric element, such as fibre, film, coating, bonding layer or foam, is made by forming a substantially linear polymer by polymerization of water soluble ethylenically unsaturated monomer blends comprising carboxylic and hydroxylic monomers and then reacting the carboxylic and hydroxylic monomers in the linear polymer to form internal cross links within the polymer.

Polymer thickeners suitable for use as textile pigment print paste thickeners are particulate cross linked polymers having a particle size of below 20 .mu.m and have defined physical characterization that indicates an optimum degree of cross linking and molecular size within the polymer.

Particulate polymers, their production and uses

When drying an aqueous polysaccharide solution, the viscosification properties are maintained, and often improved, by including a low molecular weight electrolyte in the solution before the drying is completed, and generally before the solution is heated above 50.degree. C.

Polysaccharides

An intimate water soluble or water swellable blend of microbial polysaccharide and synthetic polymer derived from water soluble monomer or monomer blend is made by forming an emulsion in non-aqueous liquid of an aqueous fermentation solution of the microbial polysaccharide and the monomer or monomer blend and then polymerizing the monomer or monomer blend to form a dispersion in non-aqueous liquid of aqueous particles of the water soluble or water swellable blend. This dispersion may then be dehydrated.

Acrylic acid or other unsaturated carboxylic acid is made by hydrolysing the corresponding nitrile in the presence of excess sulphuric acid to form amide sulphate, adding amide in an amount such that the total amount of amide and nitrile fed to the process is greater than 1 mole per mole sulphuric acid, hydrolysing the amide sulphate and amide to the desired acid and separating the acid from the sulphate by-products.

Process for producing unsaturated carboxylic acids

When flocculating an aqueous suspension of suspended solids using a high molecular weight synthetic polymeric flocculant the shear stability of the flocs is increased if the polymeric material includes polymeric particles of below 10 .mu.m dry size. The flocculated solids can therefore be subjected to shear without increasing the amount of discrete suspended solids in the aqueous medium and generally they are suspended to shear by shearing the aqueous medium containing them, either before dewatering, generally on a centrifuge, piston press or belt press, or by continuously agitating them, for instance in a chemical reaction medium. The polymeric material is generally formed by mixing into water polymeric particles made by reverse phase or emulsion polymerization in the presence of added cross linking agent. Alternatively particles insolubilized by insoluble monomer may be used. A reverse phase dispersion of water soluble polymer may be used if the particles remain undissolved, e.g. if they are added in the absence of an oil in water emulsifying agent.

Growing community of inventors

West Yorkshire, United Kingdom

Peter Flesher