Showing papers on "Potassium hydroxide published in 1995"

Inhibition of pyramid formation in the etching of Si p(100) in aqueous potassium hydroxide-isopropanol

Abstract: Production of smooth, defect-free silicon surfaces is essential for the fabrication of precise three-dimensional devices. Micromachining usually involves anisotropic etching in alkaline media such as potassium hydroxide-isopropanol mixtures (KOH/IPA). The quality of the etched surfaces is highly dependent on the etching conditions and surface inhomogeneities such as micropyramids or pits can present major problems, In the present investigation, the purity of the reagents used in the etchant and the effects of dissolved gases, such as oxygen and nitrogen, on surface finish have been evaluated for KOH/IPA baths. The purity of both the water and KOH used was found to be extremely important; the best surfaces were obtained with baths prepared with the lowest impurity content. Dissolved gases had marked effects on surface finish. Pyramid-free surfaces were obtained in oxygen-saturated etchants; this is attributed to the rapid reaction of oxygen with hydrogen produced at the surface during etching, thereby decreasing hydrogen bubble formation. The opposite was seen in solutions saturated with nitrogen where pyramid formation increased. The presence of IPA in the nitrogen-saturated bath improved the surface finish but did not prevent pyramid formation whereas with oxygen and IPA, defects were completely eliminated and surfaces with a roughness of less than 5 nm were obtained.

Solubility of potassium hydroxide and potassium phosphate in supercritical water

Abstract: The solubilities of potassium hydroxide and dibasic potassium phosphate in supercritical water solutions have been measured at temperatures from 400 to 525 C and pressures from 22.1 to 32.0 MPa. The solubility of potassium hydroxide varied from 61 mg/kg at 525 C and 22.1 MPa to 594 mg/kg at 450 C and 30.4 MPa. The solubility of dibasic potassium phosphate varied from 2 mg/kg at 450 C and 26.8 MPa to 416 mg/kg at 400 C and 27.1 MPa. The solubility was found to vary directly with pressure and inversely with temperature. Results were fit to a semiempirical solvation model to yield predictive equations for solubility as a function of water density. These studies were motivated by applications for electrolyte solubility data in the supercritical water oxidation process. Supercritical water oxidation (SCWO) is an emerging technology for the thermal destruction of organic compounds in wastewaters and sludges.

Aqueous dispersions of ethylene/ alpha , beta -unsaturated carboxylic acid interpolymers

Abstract: PCT No. PCT/US92/00622 Sec. 371 Date Aug. 27, 1992 Sec. 102(e) Date Aug. 27, 1992 PCT Filed Jan. 24, 1992 PCT Pub. No. WO92/13012 PCT Pub. Date Aug. 6, 1992.Aqueous dispersions of ethylene/ alpha , beta -unsaturated carboxylic acid interpolymers (e.g., random ethylene/acrylic acid interpolymers) are formed using a mixture of bases at a concentration of at least 0.2 equivalents of base per mole of alpha , beta -unsaturated carboxylic acid. The dispersions have at least 10 weight percent dispersed solids and not more than 1 weight percent of the initial polymer in non-dispersed form. Preferred bases for use in forming the dispersions are ammonium hydroxide and/or alkali metal hydroxides. A mixture of ammonium hydroxide and potassium hydroxide is especially preferred for forming the dispersions with ethylene/acrylic acid interpolymers at an ammonium hydroxide:acrylic acid molar ratio of 1:1 and a potassium hydroxide:acrylic acid molar ratio in the range of 0.6-0.8:1. The dispersions are particularly useful in forming thin coatings of adhesive on substrates, such as paper and metal foil, using conventional techniques.

Recycling of sheet-molding compounds by chemical routes

Abstract: This article describes a number of chemical routes for the recycling of sheet-molding compounds (SMC) consisting of glass fibers, filler (calcium carbonate), and an unsaturated polyester–styrene thermoset resin. Treatment of milled SMC with ethanol/potassium hydroxide at 85°C for 48 h ultimately affords a soluble polymeric fraction, consisting of styrene–fumaric acid copolymers. The excess of potassium hydroxide as well as the filler are removed via a neutralization step, which results in a large stream of waste chemicals. Treatment of SMC chips with ethanolamine at 180°C for 48 h gives a reaction mass that can be split into three fractions, viz., the glass fibers, the filler, and a methanol-soluble polymeric residue. The excess of ethanolamine is recovered by distillation at 220°C and reduced pressure. The polymeric fraction consists of terpolymers of styrene, N,N′-di(2-hydroxyethyl)fumaramide and N-2-hydroxyethylmaleimide monomer units, the latter two bearing two and one hydroxyl groups, respectively. The terpolymer shows little solubility in unsaturated polyester, epoxy, or isocyanate resins. The glass fibers and the filler coated with the polymeric fraction can be used as constituents of bulk-molding compounds (BMC). Replacing half of the original amount of glass fibers or filler of a standard BMC formulation by recycled materials does not significantly alter the mechanical properties. Increasing the amount of recyclate results in processing difficulties in the case of the glass fibers or a serious decline of the mechanical properties in the case of the filler/polymer. © 1995 John Wiley & Sons, Inc.

PH adjustors and drinks using the same

Abstract: A pH adjustor for drinks comprising a potassium salt as an active ingredient wherein said potassium salt comprises an effective amount for adjusting pH of at least two members selected from the group consisting of potassium carbonate, dipotassium hydrogenphosphate and potassium hydroxide, whereby the pH adjustor is capable of suppressing the deterioration of aroma and/or taste due to lowering of pH by retort sterilization.

Method of replenishing electroless gold plating baths

Abstract: A replenishing solution for a cyanide-based electroless gold plating bath. The solution includes a gold(III) halide such as gold chloride, gold bromide, tetrachloroaurate (and its sodium, potassium, and ammonium salts), and tetrabromoaurate (and its sodium, potassium, and ammonium salts). The replenishing solution also may include an alkali (such as potassium hydroxide, sodium hydroxide, and ammonium hydroxide) to maintain the pH of the solution between 8 and 14. Also provided is a method of replenishing a cyanide-based electroless gold plating bath with the solution of the present invention.

Design and synthesis of near-infrared absorbing pigments. ii: structure determination of aceanthrene green and derivatives

Abstract: The reported structure of aceanthrene green, a pigment prepared by potassium hydroxide fusion of 1,9-anthracenedicarboxylic imide, was found to be incorrect. The structure of the pigment is reassig...

Method for producing chlorine dioxide and removing chlorine dioxide using chemically impregnated zeolite

Abstract: A method for producing chlorine dioxide by moving fluid (such as air) relative to a first bed of zeolite crystals impregnated with sodium chlorine and/or zeolite crystals impregnated with chlorine, and by moving the fluid relative to a second bed of zeolite crystals impregnated with one of the following: phosphoric acid, acetic acid and citric acid. The first and second beds may be physically mixed together. A further aspect of the present invention relates to removing chlorine dioxide from a fluid by moving the fluid relative to a bed of zeolite crystals impregnated with one of the following: potassium hydroxide, sodium sulfite, sodium bisulfate and ferrous sulfate. This method may be used to remove chlorine dioxide produced using the method for producing chlorine dioxide described above.

Alkaline gel electrolyte for electrochemical cells

Abstract: An alkaline gel electrolyte for an electrochemical cell is based on a polymeric binder of polyvinyl alcohol or polyvinyl acetate. Potassium hydroxide and/or sodium hydroxide is blended into the polymeric binder or matrix, and the resulting solution is used to cast a film that is useful as a gel electrolyte. The hydroxide in the solution is between about 1% to 25% by weight, and the polymer concentration is between about 0.5% to 10% by weight. The resulting gel electrolyte film contains between 10 to 90% water by weight. A nickel or iron porphine modifier may be added in an amount between about 1 to 1000 parts per million. The alkaline gel electrolyte is useful in combination with asymmetric inorganic electrodes to make electrochemical cells, and can also function as a separator. Improved power density and higher cycle life is achieved with the gel electrolyte.

Method for reducing coffee acidity

Abstract: A method of brewing coffee having reduced acidity is disclosed In the method, an acid-neutralizing composition comprising calcium carbonate, potassium hydroxide, magnesium hydroxide, and potassium chloride is utilized to produce a brewed coffee having a pH of from about 57 to about 61 A coffee product comprising ground coffee and an acid-neutralizing composition is also disclosed

Electromembrane processes for the treatment of kraft mill electrostatic precipitator catch

Abstract: Alkali metal hydroxide and acid are recovered from alkali metal salts by water-splitting. A two-compartment cell employs monovalent anion-selective membranes and bipolar membranes; a three-compartment cell (1) employs monovalent anion-selective membranes (3), cation-selective membranes (4) and bipolar membranes (2a, 2b). A particular application is the conversion of the Electrostatic Precipitator Catch of the recovery boiler of coastal and/or closed-cycle kraft pulp mill with reuse of the sodium/potassium hydroxide and sulfate, depleted in chloride.

Purification of aniline

Abstract: PURPOSE: To readily obtain colorless aniline containing only slight amount of phenol by using a method capable of preventing increase in the viscosity of a waste oil having high boiling point from becoming hardly handleable, or by which corrosion with an alkali is scarcely generated. CONSTITUTION: An aniline solution containing phenols is added with an alkali aqueous solution having a prescribed concentration (e.g. sodium hydroxide or potassium hydroxide), mixed, allowed to stand and separated to oil and water phases, then the oil phase part is distilled under 70-200Torr pressure at 110-140°C to reduce phenol to ≤30ppm. In the process, an alkali concentration in the aqueous phase after adding the alkali aqueous solution is preferably 0.1-0.7wt.% and a molar ratio of the alkali to the phenols is preferably 3-500. This reaction can be performed either by a continuous method or a batch method. The raw aniline solution containing phenols is obtained by a hydrogenating reaction of nitrobenzene. COPYRIGHT: (C)1996,JPO

Base solution for cleaning aluminum

Abstract: A solution and solution concentrate for cleaning metal surfaces, particularly aluminum surfaces in which CaO or Ca (OH)2 is added to sulfuric acid to raise the pH to about 13.1 after which the solution is passed through an eleven micron filter and potassium hydroxide is added to raise the pH to greater than 13.8. The resulting concentrate is diluted with water to an appropriate degree, generally 15 parts concentrate to 85 parts of water such as to bring the pH down to a working range of 8.5 to 11.0, degree of dilution depending on the usage.

Alkali-activated glassy silicate foamed concrete

Abstract: The invention pertains to a cementious composition of a strong, light, foamed silicate binder or concrete made from ground, calcium-rich glassy silicates that are the major component of blast-furnace slag. The other materials used to create the material are sodium peroxide and water. The cementious mixture can include a volume modification foaming agent that substitutes a part of the mixture. These agents include sodium hydroxide, potassium hydroxide and hydrogen peroxide.

Process and device for recovering amines and use of residues obtainable thereby

Abstract: The invention relates to a process for recovering amines from acid amine salt solutions by the addition of bases and evaporating the solution at a pH of 11 to 13 in a kneading drier until a useful solid is obtained as the distillation residue and a device for separating sludges and suspensions into a solid and a plurality of liquid fractions separated according to their boiling point. The low-water-content amine phase separated out by distillation is dehydrated with calcium oxide or potassium hydroxide and then separated into pure amine fractions by rectification. The process described makes it possible to utilise all the secondary flows and completely recycle the amines and the absorption medium (sulphuric acid). The flows for the recycling process are amine-charged washing acids from absorbers obtained from the cleaning of amine-containing exhaust gases obtained, produced for instance in the cold box process for hardening core sand in foundries.

Alkaline secondary battery

Abstract: The present invention relates to an alkaline secondary battery improved in the structure of the plate substrate, and provides an alkaline secondary battery which uses a three-dimensional porous substrate which is inexpensive, improved in stability in electrolyte and inhibited from shrinkage at sintering. The battery has such a construction comprising a sealed case containing positive electrodes mainly composed of a nickel oxide, negative electrodes mainly composed of a hydrogen-absorbing alloy or a cadmium oxide, an alkaline electrolyte containing at least one component selected from the group consisting of potassium hydroxide, lithium hydroxide and sodium hydroxide and separators, the substrate used for at least one of the positive electrode and the negative electrode being a three-dimensional porous iron sintered body on the surface of which is provided a nickel coating layer.

Metal hydride electrode, nickel electrode and nickel-hydrogen battery

Abstract: A metal hydride electrode, in which a metallic cobalt powder is mixed within a mixing range of 3 to 20 weight percent, with a hydrogen absorbing alloy powder formed by substituting a part of the Ni of the alloy expressed by a rational formula of MmNi5 with Al and at least one kind of Fe, Cu, Co, Mn, and the mixed powder is loaded into a porous alkaline-proof metal body. A nickel electrode, in which a cobalt monoxide powder is mixed with an active material powder within a mixing range of 5 to 15 weight percent, the active material powder comprising zinc within a range of 2 to 8 weight percent, under a solid solution state in a crystal of nickel hydroxide powder assuming a spherical shape including an inner pore volume of 0.14 ml/g or less, and the mixed powder is loaded into a porous alkaline-proof metal body. A nickel-hydrogen battery consists of the foregoing metal hydride electrode and the foregoing nickel electrode wound together with a separator between them and immersed in an aqueous solution of potassium hydroxide and sealed, after which they are maintained under standing conditions for 5 hours or more.

Vapor Pressure of (Potassium Hydroxide + Ammonia + Water) Solutions

Abstract: Experimental results on equilibrium pressure over KOH+NH 3 +H 2 O solutions are reported. The temperature was varied between -6 and +30 o C, while the molalities of NH 3 and KOH were vied in the range 1-12 and 1-10 mol.kg -1 , respectively. An analytical equation of the equilibrium pressure as a function of temperature and concentrations was obtained. The partial molal enthalpy of solution of ammonia in the KOH+H 2 O mixtures and the Henry coefficients for ammonia were also calculated. For the ternary mixture the Setschenow relation was considered and validated in the range of measured concentrations

Aqueous cleaning composition

Abstract: Non-foaming, low foaming and high foaming liquid, aqueous cleaning compositions which comprise the components potassium hydroxide; sodium metasilicate; an additional sodium ion containing component, preferably sodium hydroxide or a polyacrylic acid neutralized with sodium hydroxide; alkyl diglycol, preferably butyl diglycol or butyl acetate; a quaternary alkylbenzyl ammonium chloride, preferably lauryl dimethyl benzyl ammonium chloride; and optionally foaming agents, fragrances and additives; which components are dissolved in water in effective amounts.

Electrolytic production of potassium permanganate using a cationic membrane in an electrolytic cell

Abstract: A method of producing potassium permanganate in an electrolytic cell is described where the cell is separated into a catholyte and anolyte region, potassium hydroxide is made in the catholyte region and is recycled back into upstream portions of the process to oxidize permanganate dioxide bearing ore.

Harmful gas purifying agent

Abstract: PURPOSE:To obtain a purifying agent capable of efficiently removing harmful acidic gas such as boron trichloride, chlorine, hydrogen chloride, hydrogen bromide, boron trifluoride, tungsten hexafluoride or silicon tetrafluoride contained in exhaust gas discharged from a semiconductor manufacturing process. CONSTITUTION:A molded element using a compsn. based on strontium hydroxide and pref. containing water is used as a purifying agent. At the time of molding, if necessary, a carrier such as alumina or sodium hydroxide, potassium hydroxide or sodium silicate being a binder is added to the compsn.

Production of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide

Abstract: PURPOSE: To industrially and advantageously obtain the subject compound useful as a water-soluble dehydration condensation reaction agent for medicines, etc., by subjecting ethyl(dimethylaminopropyl)thiourea to de-hydrogen sulfide reaction with hypochlorous acid in the presence of KOH in a two-phase system comprising an organic solvent which is incompatible with water and water. CONSTITUTION: 1-Ethyl-3-(3-dimethylaminopropyl)thiourea is subjected to de- hydrogen sulfide reaction with a hypochlorous acid salt (in an amount of 1.5-2.5 times by equivalent) in the presence of potassium hydroxide in a two phase system comprising an organic solvent (preferably a solvent having 10-100 deg.C boiling point, e.g. hexane, chloroform, methylene chloride or diethyl ether) which is incompatible with water and water to provide the objective compound useful for synthesis of medicines, agrochemicals, etc., and as a dehydration condensation reaction agent in production and an intermediate for organic synthesis.

Method for purifying cyclic olefinic polymer

Abstract: PURPOSE:To obtain a polymer, sufficiently freed of a catalyst residue containing a metal or other impurities and capable of manifesting high transparency by adding an oxidizing agent and/or a basic compound to a cyclic olefinic polymer solution and extracting and removing the impurities with a poor solvent. CONSTITUTION:This method for purifying a cyclic olefinic polymer is to carry out a step for adding an oxidizing agent to a polymer solution of the cyclic olefinic polymer produced by the ring opening polymerization using a catalyst containing a metallic element and extracting impurities with a poor solvent and/or a step for adding a basic compound to the polymer solution and extracting and removing the impurities with the poor solvent. Cerium chloride, ferric chloride, etc., are used as the oxidizing agent and lower alkyl ketones or lower alcohols are preferred as the poor solvent. Hydrochloric acid, etc., together with the oxidizing agent are preferably added to the polymer solution. The solution of the polymer is prepared in toluene, xylene, etc., as a good solvent. Sodium hydroxide, potassium hydroxide, etc., are used as the basic compound.