Abstract: The present invention relates to a process for preparing a zinc dithionite solution wherein the process comprises reacting an aqueous slurry of zinc particles with sulfur dioxide in presence of a promoter compound. The zinc particles can either be a commercial particulate zinc material or a particulate zinc material prepared by electrolyzing an aqueous alkaline suspension or slurry containing zinc based species. The addition of the promoter compound significantly increases the conversion of zinc to zinc dithionite and significantly reduces the cycle time of the reaction. The promoter compound is selected from the group consisting of sodium hydroxide and metal compounds. The promoter metal compounds are selected from the group consisting of an alkali metal hydroxide, zinc oxide, zinc sulfite, zinc bisulfite, zinc metabisulfite, an alkali metal zincate, an alkali metal sulfite, an alkali metal bisulfite, and mixtures thereof.

Abstract: The present invention provides a low corrosion electrochemical process for preparing zinc metal which comprises electrochemically reducing an aqueous alkaline slurry or solution of zinc oxide or any other compound that reacts with an aqueous base to produce zinc oxide, wherein the electrochemical process is carried out in an undivided electrochemical cell and wherein sodium bisulfide (NaSH) is added to the aqueous alkaline slurry or solution. The present invention also provides a process for preparing zinc dithionite, which comprises reacting zinc metal with sulfur dioxide, wherein the zinc metal is produced by the aforementioned electrochemical process.

Abstract: Disclosed is a process for preparing zinc dithionite comprising reacting zinc metal with sulfur dioxide, wherein the zinc metal used in the reaction is produced by electrochemical reduction in an undivided electrochemical cell of an aqueous alkaline slurry or solution of zinc oxide or any other zinc compound that reacts with aqueous base to form zinc oxide.

Abstract: Disclosed is a low corrosion electrochemical process for preparing zinc metal which comprises electrochemically reducing an aqueous basic solution or slurry of zinc oxide or any other zinc compound that reacts with an aqueous base to produce zinc oxide, wherein the electrochemical process is carried out in an undivided electrochemical cell, and wherein air or nitrogen is bubbled in through the solution or slurry of zinc oxide or said other zinc compound during said electrochemical process.

Abstract: Disclosed is an electrochemical process for preparing zinc powder which involves: a) providing to an electrochemical cell a basic solution of zinc oxide or any other zinc compound that reacts with an aqueous base to produce zinc oxide, the basic solution prepared by dissolving the zinc oxide or the other zinc compound in an aqueous 2.5 to 10.0 M base solution; and b) passing current to the cell at a current density of about 10,000 to about 40,000 A/m2 for a time period sufficient to electrochemically reduce the zinc oxide to zinc powder, wherein the electrochemical process has a current efficiency of at least 70% and is substantially free from electrode corrosion.

Abstract: The present invention relates to a continuous electrochemical process for preparing zinc powder. The process involves providing to an electrochemical cell a suspension in a 1.25 Molar to 10.0 Molar aqueous alkaline solution of zinc oxide or any other zinc compound that reacts with an aqueous alkaline solution to produce zinc oxide, such that the solution or suspension comprises at least 2 millimoles of solubilized zinc based species per 100 grams of electrolyte. Current is passed to the cell at a current density of about 500 to 40,000 A/m2, for a time period sufficient to electrochemically reduce the solubilized zinc based species to zinc powder, while continuously or intermittently adding a sufficient amount of the zinc oxide or the other zinc compound to the cell to maintain the concentration of the solubilized zinc based species at a level of at least 2 millimoles per 100 grams of electrolyte.

Abstract: The present invention provides a composition comprising a saturated solution of zinc oxide in an aqueous sodium or potassium hydroxide solution wherein the concentrations of the zinc oxide and the sodium hydroxide in said solution are as set forth in FIG. 1, and the concentrations of the zinc oxide and potassium hydroxide are as set forth in FIG. 2.

Abstract: Disclosed is a continuous electrochemical process for preparing zinc powder which involves: providing to an electrochemical cell a solution or suspension in an aqueous 1.25 Molar to 10.

Abstract: Disclosed is an electrochemical process for preparing zinc powder which involves: a) providing to an electrochemical cell a basic solution of zinc oxide or any other zinc compound that reacts with an aqueous base to produce zinc oxide, the basic solution prepared by dissolving the zinc oxide or the other zinc compound in an aqueous 2.5 to 10.0 M base solution; and b) passing current to the cell at a current density of about 10,000 to about 40,000 A/m2 for a time period sufficient to electrochemically reduce the zinc oxide to zinc powder, wherein the electrochemical process has a current efficiency of at least 70% and is substantially free from electrode corrosion.

Abstract: An improved electrochemical process for thiocyanating aminobenzene compounds (e.g., 3,4-dichloroaniline), and in particular a process for preparing 2-aminobenzothiazole compounds, is disclosed which provides attractive yields under relatively favorable temperature conditions, and with reduced or minimal cyanide formation. In a further aspect, use of quaternary ammonium salts in the thiocyanation medium has been found to inhibit cathodic corrosion.

Abstract: An improved process for reducing aromatic nitro compounds to form the corresponding aromatic amine compounds, and intermediates therefore, and a reducing agent therefor, are disclosed. According to the process, a titanium(IV)oxy salt such as titanium(IV) oxysulfate is electrochemically reduced to form a titanium(III)oxy reducing agent, which can be employed to chemically reduce the aromatic nitro compounds, and the resulting re-oxidized titanium salts may be recycled to the electrochemical reduction step of the process. The titanium(III)oxy salt product is highly soluble in strong acid solutions and exhibits improved oxidation stability.

Abstract: A process is disclosed for electrochemically treating p-nitrotoluene-2-sulfonic acid salts under oxidizing conditions to form 4,4'-dinitrostilbene-2,2'-disulfonic acid or the salts thereof. The process provides satisfactory yields of the stilbene compound while enabling substantial recycling of reaction materials. Substantial benefits are obtained when lithium hydroxide is employed in the reaction medium, including recovery of product of high purity, and improved recovery and recycling of lithium to the process.

Abstract: An antioxidant for lubricating oils comprising an amine compound selected from substituted benzylamines or a substituted 1-amino-1,2,3,4-tetrahydro-naphthalene. The preferred anti-oxidants are N-(alpha -methyl -p -octylbenzyl) aniline, N-(alpha-methylbenzyl)- p -nonylaniline or 1-( p -dodecylanilino)-1,2,3,4-tetrahydronaphthalene.

Abstract: Polyurethane sealant and coating compositions made from blocked isocyanate-terminated prepolymers have improved shelf stability when an effective amount of a carbodiimide is utilized therewith. Such compositions and coating materials can be stored in sealed containers or cartridges for relatively long periods of time, for example in excess of five or six months, without significant loss of curability which adversely affects physical properties upon cure. One part as well as two part polyurethane sealant and coating compositions are stabilized by the addition of the carbodiimide stabilizing agent whereas the addition of an organosilane abates viscosity increase during storage.

Abstract: A urethane sealant or coating composition is made from a physical blend of a polypropyleneoxide polyol intermediate and an organic-silicone block copolymer based polyol intermediate. The urethane prepolymer is made by reacting the physical intermediate blend with a polyisocyanate and preferably blocking the same with blocking agents such as phenols to prevent reaction with moisture in the air. Cure is effected through the utilization of curing agents such as polyamines or polyimines, for example, diamines, amine terminated polyethers, ketimines, aldimines, and the like. The sealant composition can contain various fillers, organosilanes, and the like. The prepolymers of the present invention generally have improved elongation and reduced modulus. Either a one-part or a two-part system can be utilized.

Abstract: A high performance urethane sealant or coating composition is made from a physical blend of a polypropyleneoxide polyol intermediate and a high molecular weight polybutyleneoxide polyol intermediate or copolymers thereof wherein the comonomer is preferably ethyleneoxide. The urethane prepolymer is made by reacting the physical intermediate blend with a polyisocyanate and preferably blocking the same with blocking agents such as phenols to prevent reaction with moisture in the air. Alternatively, the prepolymer can be end capped with an epoxy. Cure is effected through the utilization of curing agents such as polyamines or polyimines, e.g., diamines, amine terminated polyethers, ketimines, aldimines, and the like. The sealant composition can contain various fillers, organosilanes, and the like. The prepolymers as well as the sealants of the present invention have improved physical rubbery type properties such as higher elongation, lower modulus, and generally improved tensile strength.

Abstract: A sealant or coating composition admixture contains a blocked isocyanate-terminated prepolymer in which generally all of the NCO groups are blocked, a curing agent such as a polyamine or a polyimine, and a functional silane or siloxane nonreactive with blocked isocyanates. The sealants or coating compositions when cured have improved properties such as adhesion.

Abstract: A polymer of monoallylamine, preferably a water-soluble polymer of monoallylamine, whether in free (i.e., unneutralized) form or in salt (i.e., partially or completely neutralized) form is used in conjunction with a sulfonated polymer such as a water-soluble lignosulfonate, condensed naphthalene sulfonate, or sulfonated vinyl aromatic polymer, to minimize fluid loss from the slurry during subterranean well cementing operations. The polymer of monoallyl amine may be a homopolymer or a copolymer, and may be crosslinked or uncrosslinked. These components interact with each other in the presence of water to produce a gelatinous material that tends to plug porous zones and minimize premature water loss from the well cement slurry when present in the subterranean well formation. In addition, the gelatinous material so formed prevents de-stabilization of the slurry in the well formation.

Abstract: A polymer of monoallylamine, preferably a water-soluble polymer of monoallylamine, whether in free (i.e., unneutralized) form or in salt (i.e., partially or completely neutralized) form is used in conjunction with a sulfonated polymer such as a water-soluble lignosulfonate, condensed naphthalene sulfonate, or sulfonated vinyl aromatic polymer, to minimize fluid loss from the slurry during subterranean well cementing operations. The polymer of monoallyl amine may be a homopolymer or a copolymer, and may be crosslinked or uncrosslinked. These components interact with each other in the presence of water to produce a gelatinous material that tends to plug porous zones and minimize premature water loss from the well cement slurry when present in the subterranean well formation. In addition, the gelatinous material so formed prevents de-stabilization of the slurry in the well formation.

Abstract: A polymer of monoallylamine, preferably a water-soluble polymer of monoallylamine, whether in free (i.e., unneutralized) form or in salt (i.e., partially or completely neutralized) form is used in conjunction with a sulfonated polymer such as a water-soluble lignosulfonate, condensed naphthalene sulfonate, or sulfonated vinyl aromatic polymer, to minimize fluid loss from the slurry during subterranean well cementing operations. The polymer of monoallyl amine may be a homopolymer or a copolymer, and may be crosslinked or uncrosslinked. These components interact with each other in the presence of water to produce a gelatinous material that tends to plug porous zones and minimize premature water loss from the well cement slurry when present in the subterranean well formation. In addition, the gelatinous material so formed prevents de-stabilization of the slurry in the well formation.