Abstract: The invention is directed to the composition and use of substantially water-soluble amphoteric (co)polymers as co-binders for paper and paperboard coating applications.

Abstract: The invention is directed to the composition and use of substantially water-soluble amphoteric (co)polymers as co-binders for paper and paperboard coating applications.

Abstract: A method of sizing paper by applying a composition comprising an aqueous dispersion of polymeric particles of particle size up to 1 micron, preferably 80-200 nm, wherein the polymeric particles comprise a water insoluble polymer matrix, preferably formed from styrene and 2-ethylhexyl acrylate, characterized in that an oligomer formed from a monomer blend comprising, (a) (meth)acrylamide, and (b) organic mercaptan or an organic sulphone, preferably dodecyl mercaptan or dodecyl sulphone is located at the surface of the particles. Compositions where the oligomer further comprises an ethylenically unsaturated monomer comprising either a tertiary amine group or a quaternary ammonium group, preferably dimethylaminoethylmethacrylate are novel. Advantages of the composition when applied to the surface of paper, include improved water resistance, brightness and printability properties of the treated paper.

Abstract: A process for making paper comprising forming a cellulosic suspension, flocculating the suspension, draining the suspension on a screen to form a sheet and then drying the sheet, wherein the cellulosic suspension is flocculated by addition of a water soluble polymer which is selected from a) a polysaccharide or b) a synthetic polymer of intrinsic viscosity at least 4 dl/g and then reflocculated by a subsequent addition of a reflocculating system, wherein the reflocculating system comprises i) a siliceous material and ii) a water soluble polymer. In one aspect the siliceous material is added prior to or simultaneous with the water soluble polymer. In an alternative for the water soluble polymer is anionic and added prior to the siliceous material.

Abstract: A process and apparatus therefore in which a sludge treatment stage 24 is controlled in response to the density or solids content of the sludge includes flowing sludge along a flow line 1 towards the treatment stage, taking a sample from the flow line 1, degassing the sample to produce a degassed sample, measuring the density or solids content of the degassed sample, and utilizing the measured degassed density or solids content of the degassed sample for controlling the treatment stage 24.

Abstract: The invention provides an aqueous soil treatment composition comprising water and, (a) a calcium compound, (b) a water-soluble anionic polymer which has intrinsic viscosity of less than 30 dl/g and is formed from water-soluble monomer or monomer blend of which less than 40% by weight is anionic monomer.

Abstract: A solution having a high concentration of ammonium (meth)acrylate and which is substantially free of (meth)acrylonitrile is made by enzymatic hydrolysis of (meth)acrylonitrile in the presence of water using an enzyme that has Km for (meth)acrylonitrile below 500 &mgr;m and Ki for ammonium (meth)acrylate about 100,000.

Abstract: Particles have a hydrophilic core, for instance including an enzyme and a polymer, surrounded by a shell formed by interfacial condensation polymerisation in the presence of a polymeric stabilizer. Preferably the polymeric stabilizer is a random copolymer which will concentrate at the interface between oil and water and association by ionic interaction, condensation or otherwise is achieved between the stabilizer and one of the reactants before reaction with the other reactant. Dispersions of aqueous capsules in an aqueous medium are also disclosed.

Abstract: Polymer particles comprising a hydrophobic organic matrix and located at the exterior free cationic groups and a further polymer which comprises free hydroxy groups. The particles are produced by an aqueous suspension polymerization process wherein the continuous aqueous phase contains a polymerization stabilizer and a dissolved vinyl addition cationic monomer. The polymerization stabilizer can be any suitable polymer that comprises free hydroxy groups. The process results in polymers of average particle size in the range 50 to 150 microns and reduced levels of undesired polymer emulsion or undersized particles. The particles are particularly useful for absorbing water insoluble active ingredients, such as insecticides, insect repellents, fragrances, pheromones for subsequent slow release. The cationic surface character of said polymer particles makes them especially useful for forming stable dispersions or slurries in active concentrates such as perfume bases or detergent concentrates.

Abstract: Paper is made by a dual soluble polymer process in which a cellulosic suspension which usually contains alum or cationic coagulant is first flocculated with a high IV cationic synthetic polymer or cationic starch and, after shearing, the suspension is reflocculated by the addition of a branched anionic water soluble polymer having IV above 3 dl/g and tan delta at 0.005 Hz of at least 0.5. The process gives an improved combination of formation, retention and drainage.

Abstract: A composition (1) comprising water, in solution, a) an inorganic water-soluble compound in an amount of at least 10%, b) an anti-drift agent which is a water soluble anionic polymer of intrinsic viscosity at least 6 dl/g which is formed from water soluble monomer or monomer blend, characterized in that the water-soluble polymer (b) is present in an amount up to 1.9 wt. % based on weight of composition. Said composition (1) can be a liquid fertilizer concentrate that can conveniently be applied through conventional spray distribution equipment without the need for additional dosing of anti-drift control chemicals. Said composition (1) can be a low viscosity liquid anti-drift agent that can be combined with a herbicide or pesticide in conventional spray distribution equipment.

Abstract: Sizing dispersions of liquid reactive size are made by dispersing the reactive size as a neat liquid into a dispersion of bentonite or other anionic microparticulate material in water. These dispersions can be used for internal sizing, for instance wherein the dispersion is used as the anionic microparticulate stage in a microparticulate retention paper-making process, or they can be used for external sizing.

Abstract: A process for producing &agr;-amino acid from starting material comprising &agr;-amino amide enantiomers (A) and (B) is such that enantiomer (A) is converted preferentially over enantiomer (B) so that a time independent excess of at least 90%, preferably at least 98% is given. The reaction is catalyzed by an amidase which may in particular be produced by specific Rhodococcus species.

Abstract: Cellulosic fines and cellulosic fibers are separated from a suspension containing the fines, the fibers and hydrophobic materials by screening the suspension to remove the fibers, and then subjecting the resultant filtrate to dispersed air flotation in the presence of calcium and generally a separation aid to form an upper Reject fraction in which the hydrophobic material is concentrated and a lower Accept fraction in which the cellulosic fines are concentrated.

Abstract: Starch is added to the thinstock in a papermaking process in the form of a coagulated slurry containing undissolved starch particles, cationic polymeric flocculant and anionic microparticulate network agglomeration aid, such as bentonite. The flocculant and agglomeration aid interact to give network flocculation in which the starch particles are trapped. Improved retention of the starch in the resulting paper is achieved.

Abstract: A process of thickening an aqueous suspension of mineral solids by sedimentation comprising adding to the suspension water-soluble anionic bridging polymeric flocculant having intrinsic viscosity at least 5 dl/g and water-soluble cationic polymeric flocculant, allowing the solids to settle under gravity so as to form a lower underflow fraction containing a concentration of solids greater than that of the suspension and an upper overflow fraction containing a concentration of solids lower than that of the suspension and removing the underflow fraction, characterised in that the anionic and cationic flocculants are added to the suspension as an aqueous composition formed by blending 1 part by weight of the cationic polymeric flocculant with 2 to 99 parts by weight of the anionic polymeric flocculant and sufficient water to give a total polymer concentration of below 5 wt % and under conditions whereby counter-ionic precipitation can occur and in the aqueous composition substantially all of the anionic polymer

Abstract: A dispersion in a liquid electrolyte (such as a detergent concentrate) of particles having a core containing an enzyme or other detergent active ingredient and a shell made by interfacial condensation is stabilised by covalently reacting a stabiliser on to reactive groups on the shell.

Abstract: A process of recovering alumina from a pregnant Bayer process liquor by crystallisation after adding to the liquor a crystallisation modifier characterised in that the crystallisation modifier comprises: (a) a polyalkoxylated non-ionic surfactant, (b) a surfactant, or precursor thereof, which is not a polyalkoxylated non-ionic surfactant and (c) water. In a further aspect of the invention the composition may contain water but preferably contains substantially no water. Preferred compositions for the crystallisation modifier for use in this process contain a surfactant blend which consists essentially only of the polyalkoxylated non-ionic surfactant (a) and the surfactant (b) or precursor thereof. The process consistently gives excellent improvement in crystal size without decreased yield. Specifically the process results in a reduction in the percentage of undersized crystals.

Abstract: A solution having a high concentration of ammonium (meth)acrylate and which is substantially free of (meth)acrylonitrile is made by enzymatic hydrolysis of (meth)acrylonitrile in the presence of water using an enzyme which has Km for (meth)acrylonitrile below 500 .mu.m and Ki for ammonium (meth)acrylate above 100,000.

Abstract: A process is provided for pelletising a metal ore comprising forming an intimate mixture of particulate ore and a binder in the presence of moisture, forming green pellets by agitation of the mixture and firing the green pellets to produce ore pellets. In the process the binder comprises a hydroxamate polymer made from water-soluble ethylenically unsaturated monomer or monomer blend and which has pendant groups of the formula ##STR1## This provides advantages in wet strength, dry strength and drop number of pellets, especially at low moisture content of the pellets.