Abstract: A suspension may be flocculated using a water soluble substantially linear polymer having a single point intrinsic viscosity above 3 and that is a copolymer of two or more ethylenically unsaturated monomers including at least 0.5% by weight of monomer carrying pendant hydrophobic groups. The cationic polymers are novel. Preferred polymers are those in which the hydrophobic group is introduced as an allyl ether.

Abstract: Aqueous well fluids, such as completion, stimulation and work over fluids contain, as a viscosifier, a polymer having recurring units derived from monomers of the formulaCH.sub.2 .dbd.C(R.sup.1)CONHR.sup.2 NR.sup.3 R.sup.4wherein R.sup.1 is hydrogen or methyl, R.sup.2 is straight or branched chain is C.sub.2-8 alkylene having at least 2 carbon atoms in the backbone and R.sup.3 and R.sup.4 are independently selected from C.sub.1-4 alkyl. Preferred units are derived from dimethylaminopropyl methacrylamide, generally as an acid addition salt. The fluids may contain high ion concentrations. The fluids may be used in processes in which they are maintained downhole for long periods of time at high temperatures.

Abstract: A polymer of an ethylenically unsaturated monomer containing a pendant hydrophobic group and, optionally, other monomers such as (meth) acrylic acid, ethyl acrylate or acrylamide is provided as a stable, substantially anhydrous dispersion containing at least 40% by weight of the polymer in a continuous phase of a non-aqueous liquid. The polymer in the dispersion generally includes acid groups and is neutralized, preferably with ammonia or a volatile amine. The dispersion can be made by reverse phase polymerization of an aqueous blend of monomers, followed by dehydration, or by making the polymer from a water insoluble blend of monomers by oil in water emulsion polymerization, dispersing the resultant oil in water emulsion into the non-aqueous liquid, and then dehydrating. The monomer including the hydrophobic group is preferably an allyl ether.

Abstract: Sulphonated polymers and copolymers are used as thinners in aqueous drilling or packer fluids. The sulphonated polymer has polydispersity below 2 and has a low solution viscosity. It is generally a copolymer of beta-acrylamidoalkane sulphonate or allyl sulphonate or other aliphatic sulphonate with an ethylenically unsaturated carboxylic acid, generally acrylic acid.

Abstract: A water miscible, stable, fluid product comprises particles above 20 microns in size of a high molecular weight polymer gel interconnected by a continuous phase that is an aqueous solution of an equilibrating agent that holds the water content of the particles in equilibrium with the water content of the aqueous phase and that prevents substantial agglomeration of the particles in the fluid product. Preferred equilibrating agents are sodium polyacrylate and poly-diallyl dimethyl ammonium chloride.

Abstract: An ester interchange process, preferably for the formation of vinyl higher esters from methyl acrylate or methacrylate, is conducted in the presence of a novel alcoholate of the formula[M.sup.1 (OR.sup.4).sub.2-a R.sub.a.sup.6 ].sub.x [M.sup.2 (OR.sup.4).sub.n-b R.sub.b.sup.6 ].sub.y IwhereinM.sup.1 is selected from Mg, Ca and BaM.sup.2 is selected from Ti, Zr and Aln is 3 or 4 and is the valency of M.sup.2a is a number from 0 to 1.5b is a number from 0 to 0.75nx+Y=1 and each is a number from 0.005 to 0.995 and is such that the compound is liquid at 30.degree.0 C.R.sup.4 is selected from alkyl having at least 4 carbon atoms, cycloalkyl having at least 4 carbon atoms and aminoalkyl, andeach group R.sup.6 is individually selected from C.sub.1-3 alkoxy and blocking groups that are substantially less reactive in the ester interchange reaction than the groups OR.sup.4.

Abstract: A stable, water dispersable, substantially anhydrous disperson of water soluble or water swellable polymer particles in water immiscible liquid is made by reverse phase suspension polymerization and dehydration of the dispersion and is rendered dispersable in water by the addition of an oil soluble surfactant having HLB above 7.

Abstract: An exothermic gel polymerization process conducted in the presence of water is initiated at a low temperature, is held for most of the process at a higher temperature by including in the medium a particulate heat sink material, such as sodium sulphate decahydrate, that is substantially insoluble in the medium and which undergoes an endothermic phase change and is then allowed to rise to a higher temperature. Either as a result of the endothermic change, or as a result of a subsequent exothermic change, at the end of the process the heat sink material is again solid particulate material substantially insoluble in the medium and so the product is a dispersion of the material in a polymer gel. The polymer is water soluble.

Abstract: A substantially anhydrous mixture of methanol with an organic compound with which it forms an azeotrope can be separated by dissolving into the mixture lithium chloride or other suitable salt that forms a complex with methanol so as to form a homogeneous mixture, adding an organic solvent that is miscible with the organic compound but immiscible with the complex and thereby forming a heterogeneous mixture, and separating the phases. The methanol can be recovered from one phase and the organic compound from the other. The organic compound may typically be methyl acrylate or methacrylate, the blend being, for instance, obtainable during the transesterification of methyl (meth)acrylate with an alcohol to form a higher boiling ester such as dimethylaminoethyl (meth)acrylate or 2-ethylhexyl acrylate.

Abstract: Pigment dispersions contain, as dispersing agent novel water soluble polymers containing acid groups, preferably polyacrylic acid or copolymers of polyacrylic acid with AMPS, having polydispersity below 1.5 and molecular weight in the range about 1,000 to about 5,000.

Abstract: A water soluble polymer containing acid groups can be fractionated into higher and lower molecular weight fractions by partial neutralization of the polymer as a solution in a blend of water and a low molecular weight alcohol and separating the resultant aqueous and organic phases.

Abstract: A vinyl ester of the formula R.sup.3 COOR.sup.4 where R.sup.3 is CH.sub.2 .dbd.CH-- or CH.sub.2 .dbd.C.CH.sub.3 -- and R.sup.4 contains at least four carbon atoms and is selected from alkyl, cycloalkyl and aminoalkyl is conducted by reaction of an ester R.sup.3 COOR.sup.1, where R.sup.1 is C.sub.1-3 alkyl, with metal alcoholate formed from an alcohol R.sup.4 OH and titanium, aluminum, zirconium, calcium or magnesium in the absence of water or reactive alcohol.

Abstract: A nitrile, such as acrylonitrile, is hydrated to the corresponding amide in the presence of a Raney copper catalyst that, before use in the reaction, is partially oxidized by contact with a controlled oxidizing system comprising oxygen, peroxide, iodate, chlorate, bromate or nitrate.

Abstract: Concentrated (e.g. above 72% by weight) dispersions of calcium carbonate ground to a particle size such that at least 87% by weight of the particles are less than 2 .mu.m in size have a tendency to gel on standing. In the invention this tendency is minimized or eliminated by using, as dispersing agent, a copolymer of from 5 to 75% by weight AMPS and 95 to 25% by weight acrylic acid, or a water soluble salt thereof, having a molecular weight in the range 1000 to 20,000.

Abstract: Pigment dispersions contain, as dispersing agent novel water soluble polymers containing acid groups, preferably polyacrylic acid or copolymers of polyacrylic acid with AMPS, having polydispersity below 1.5 and molecular weight in the range about 1,000 to about 5,000.

Abstract: A water soluble polymer containing acid groups can be fractionated into higher and lower molecular weight fractions by partial neutralization of the polymer as a solution in a blend of water and a low molecular weight alcohol and separating the resultant aqueous and organic phases.