Abstract: Paper or paper board is made by adding cationic polymeric retention aid to a cellulosic supension, shearing the suspension to degrade the resultant flocs, aggregating the suspension by adding an aqueous composition of bentonite or other anionic bridging coagulant in the presence of anionic dye, pigment or optical brightening agent, and forming paper from the aggregated suspension.

Abstract: A dispersion is formed of aqueous polymer particles in a non-aqueous liquid and a stabiliser is covalently reacted on to the particles.

Abstract: The invention provides an aqueous polymer dispersion in which the copolymer is formed from70 to 90% by weight alkyl methacrylate provided by 0 to 30% by weight C.sub.1-3 alkyl methacrylate and 50 to 90% by weight C.sub.4-12 alkyl methacrylate;5 to 20% by weight styrene or alkyl styrene;2 to 10% by weight water soluble ethylenically unsaturated monomer;0.5 to 4% polyethylenically unsaturated monomer; and0 to 4% carbonyl containing ethylenically unsaturated monomer. The dispersion of the invention is particularly suitable for incorporation into compositions for coating on wood.

Abstract: A plant for conditioning and dewatering a suspension comprises a belt press, centrifuge or other continuous dewatering apparatus (3), a flow-line (1) leading to the dewatering apparatus, a pump (2) for causing suspension to flow along the line (1), means (5-9) for dosing conditioner into he suspension at a dosing point (4), means (12) for measuring density D, means (10) for measuring the flow rate V and thereby for calculating the dry mass per unit time M, and control means (16, 17, 18) for automatically dosing a mount A of conditioner into the suspension where A-kM and k is a constant and for automatically varying V in response to D and for automatically varying the constant k in response to D.

Abstract: Paper strengthened by starch, typically in amounts of 3 to 15% dry weight, is made by flocculating a cellulosic suspension using a polymeric retention aid which can be dissolved cationic starch but is preferably a synthetic polymer having IV above 4 dl/g, optionally shearing the resultant flocculated suspension and reflocculating it by adding bentonite or other microparticulate anionic material, draining the flocculated or reflocculated suspension and drying the resultant wet sheet, wherein insoluble particles of starch are added to the suspension as a slurry of substantially freely dispersed particles in part or all of the aqueous solution of the polymeric retention aid or in part or all of the aqueous suspension of microparticulate anionic material.

Abstract: A print paste composition contains, as binder, a curable polymer which is free of N-methylol groups and which contains anhydride-forming dicarboxylic acid and/or dicarboxylic anhydride groups which can react with hydroxyl groups in the cotton or other textile substrate and/or with hydoxyl or epoxy groups in the curable polymer.

Abstract: A suspension is dosed with a coagulant and then with a flocculant and is dewatered to form a thickened sludge or cake and separated liquor, and control of the dewatering performance is improved by adding the flocculant at a predetermined dosage, monitoring the charge in the separated liquor (or monitoring other dewatering parameter of the separated liquor or suspension) and adding coagulant at a dosage selected in response to the monitored charge or other parameter value in order to maintain the value substantially at a preselected optimum value.

Abstract: Reverse phase polymer particles having a size below 10 .mu.m are provided as a solid product comprising a solid dispersion of the particles in a wax matrix which is solid at 20.degree. C. and which melts below 250.degree. C. The product may be made by dissolving the wax into the organic liquid phase of the product of a reverse phase emulsion polymerisation process followed by distillation of the organic liquid and cooling of the resultant product. The product is generally in particulate form and can be used as a flocculant or viscosifier, especially as a textile print paste thickener.

Abstract: Filled paper is made by adding a cationising amount of cationic polymer to a slurry of precipitated calcium carbonate, mixing this slurry into a cellulosic suspension and forming a thin stock, adding anionic particulate material to the suspension before or after the slurry, mixing a polymeric retention aid into the thin stock which includes the precipitated calcium carbonate and the anionic particulate material, draining the thin stock on a screen to form a sheet and drying the sheet. A suitable slurry for this purpose is a slurry of 5 to 70% by weight precipitated calcium carbonate and cationic polymer selected from 0.1 to 1% cationic starch and 0.01 to 0.3% of a high charge density, relatively low molecular weight, cationic polymer.

Abstract: A process for the production of stable fluid enzyme dispersions having a content of at least 0.5% by weight enzyme, in which the enzyme is present in the form of anhydrous particles of a diameter less than 30 .mu.m, comprising emulsifying an enzyme composition into a water immiscible liquid in the presence of a polymeric dispersion stabilizer to form a stable dispersion of aqueous enzyme particles having a dry size below 30 .mu.m dispersed in the liquid, and dehydrating the dispersed particles by azeotropic distillation, wherein before, during or after dehydrating the particles the process comprises adding an organic liquid which is less volatile than the water immiscible liquid and which is selected from surfactants and water miscible liquids to the dispersion and distilling the water immiscible liquid from the dispersion until the amount of the initial water immiscible liquid remaining in the dispersion is below 20% by weight of the liquid phase in the dispersion.

Abstract: Filled paper is made by adding a cationising amount of cationic polymer to precipitated calcium carbonate or other filler either as a slurry or in a thick stock component, producing a thin stock containing the cationised filler and then treating the thin stock with a formaldehyde resin and polyethylene oxide as a retention system prior to drainage and drying.

Abstract: Soil adjacent to an elongated furrow is irrigated by flowing the water from a header into and along the furrow, and erosion of the furrow is reduced and infiltration into the soil is increased by dissolving solid flocculant in the header or in the furrow into the water. The solid flocculant is best provided as a block of particulate flocculant bonded by a water-soluble wax. The irrigation process is best conducted on a cyclic basis with the solid flocculant being removed from the header or furrow during the cycle and with the supply of water being continued so that there is subsequent run-off of water from the furrow.

Abstract: Flexographic or other printed paper is deinked by a process which comprises pulping in the presence of an emulsion of crosslinked, insoluble, ionisable and swellable polymer particles. The emulsion preferably provides a viscosity (at 3%) in the ionised state of below 50,000 cps (Brookfield RVT) and is novel.

Abstract: Stickies derived from pulping or deinking of cellulosic material are controlled by adding to the cellulosic liquor containing the stickies an emulsion in water of cross-linked, insoluble, ionisable and swellable polymer particles.

Abstract: Release of an active ingredient can be controlled and the active ingredient can be protected from the environment during storage, by distributing it throughout a matrix containing a relatively large amount of polymeric material that is soluble and swellable in aqueous alkali but less soluble and swellable at a lower pH value and which is in the form of a dried oil-in-water emulsion of the polymer or a relatively insoluble partial salt of the polymer with a volatile amine, the full salt of the polymer being relatively soluble. The composition is of particular value for the protection of detergent enzymes.

Abstract: During the manufacture of paper from a cellulosic suspension, retention is improved by adding to the suspension a water soluble cationic polymer containing 0.1 to 15 mole % cationic monomer groups and having an intrinsic viscosity of at least 4 dl/g and then adding a substantially water soluble formaldehyde condensate resin. This resin is preferably a phenol sulphone formaldehyde resin. Preferred phenol sulphone formaldehyde resins are materials wherein at last 70 mole % of the recurring groups are dihydroxyl phenyl sulphone groups free of sulphonic acid groups.

Abstract: A flocculant, viscosifier or other water soluble or water swellable particulate polymer is formulated as a block having a dimension of at least 10 mm and which comprises a wax matrix in which the polymer particles are dispersed. The block can be made by blending polymer powder with the molten wax matrix and cooling and solidifying it. The block is of particular value for releasing flocculant into a flowing stream of suspension.

Abstract: The invention provides a downhole process for the reduction of the permeability to water of a microporous subterranean formation which has average permeability of not greater than 10 Darcy,the process comprisingapplying to the formation a dispersion in non-aqueous liquid of water swellable, reverse-phase polymerized, substantially spherical particles of absorbent polymer of which at least 90% by weight have a diameter less than 10 .mu.mwhereby the dispersion of the substantially spherical particles of which at least 90% by weight have a size below 10 .mu.m is injected into the micropores of the subterranean formation and the particles are allowed to swell on contact with water and cause the reduction in permeability.

Abstract: An aqueous suspension of coagulatable material is coagulated by adding polymeric coagulant to the suspension and then separating the resultant coagulated material from the liquor. The coagulatable material may be present in the aqueous suspension as a suspension of suspended solids or as colloidally dispersed solids. The suspension may be coal tailings or other aqueous (generally mineral) suspension. The polymeric material must be a low molecular weight, highly ionic, polymeric material formed from a diallyl dialkyl ammonium salt. It is added to the aqueous suspension while in the form of polymeric particles having a size mainly above 30 .mu.m and that will dissolve into the suspension and coagulate the coagulatable material. An anionic high molecular weight, flocculant is generally added subsequently in order to flocculate the coagulated material.

Abstract: A phosphate feed is separated into an enriched phosphate fraction and a waste aqueous stream which includes recoverable phosphate feed particles in an aqueous clay slime and which is flowed along a flow passage through a settling zone (where recoverable phosphate feed is recovered) into a quiescent sedimentation area where the slime settles, and water soluble polymeric flocculant for the slime is added to the aqueous stream to promote settling of the phosphate feed particles substantially without settling of slime in the settling zone and to accelerate sedimentation of flocculated slime in the sedimentation zone.