Showing papers on "Ammonium hydroxide published in 1996"

Method for manufacturing cobalt catalysts

Abstract: A method for manufacturing cobalt complexes having the formula: [Co(NH3)5M]Ty, wherein M ligands are selected from substituted and unsubstituted C1-C30 carboxylic acids having the formulas: RC(O)O-; said method comprising reacting cobalt (II) complexes having the formula [Co(H2O)6] Ty (e.g., T is chloride) with concentrated ammonium hydroxide/ammonium chloride, followed by an oxidizing agent (e.g., peroxide), followed by carboxylic acid anhydride of the formula RC(O)O(O)CR.

Silver Electrocrystallization on Vitreous Carbon from Ammonium Hydroxide Solutions

Abstract: The early stages of the electrolytic deposition of silver onto vitreous carbon electrodes from ammonium hydroxide solutions have been investigated by the potential step technique. The analysis of the experimental current transients according to existing theories indicates that this process occurs by multiple three-dimensional nucleation, followed bydiffusion controlled growth of nuclei. It is shown that treatments that involve classifying the process as either instanta-neous or progressive nucleation are not always adequate for the quantitative analysis of electrochemical nucleation phe-nomena. The nucleation kinetics parameters A (nucleation rate constant per site) and No (number density of active siteson the substrate surface) were estimated separately from the current transient maxima by two different approaches. Bothquantities were found to vary with the potential and with the concentration of silver ions, except at very high overpo-tentials for silver deposition. The potential dependence of the nucleation rate A was interpreted according to the atom-istic theory and in all cases it was found that the number of atoms in the critical nucleus (nk) was one over the entirepotential range analyzed.Introduction

An aqueous shower rinsing composition and a method for keeping showers clean

Abstract: The invention relates to a composition for an aqueous rinsing solution for removing deposits from surfaces of showers and the like, and the use of such a composition for rinsing showers clean and for providing a pleasant sheen to shower surfaces without scrubbing or wiping. The composition includes a non-ionic surfactant having an HLB of less than 13, a chelating agent, and optionally, alcohol and/or ammonium hydroxide and/or morpholine.

Wafer-cleaning solution and process for the production thereof

Abstract: A wafer-cleaning solution comprising 20 to 60 wt.% of hydrogen fluoride containing 0.1 to 1000 ppm of at least one compound selected from among CnH2n+1ph(SO3M)Oph(SO3M), CnH2n+1phO(CH2CH2O)mSO3M and CnH2n+1O(CH2CH2O)mSO3M (wherein ph is phenylene; n is 5 to 20; m is 0 to 20; and M is hydrogen or a salt group) dissolved therein, and the balance of water (with the total amount being 100 wt.%); and a process for producing a wafer-cleaning solution by adding water, H2O2, HNO3, CH3COOH, NH4F and so on to the above solution. Another wafer-cleaning solution comprising HF, H2O2, HNO3, CH3COOH, NH4F, HCl, H3PO4, at least one ammonium hydroxide of the general formula: [(R1)(R2)(R3)(R4)N]+OH- (R1, R2, R3 and R4 being each independently optionally hydroxylated C1-C6 alkyl), 0,01 to 1000 ppm of at least one surfactant selected from among CnH2n+1ph(SO3M)Oph(SO3M), CnH2n+1phO(CH2CH2O)mSO3M and CnH2n+1O(CH2CH2O)mSO3M (wherein ph, n, m and M are each as described above) which is dissolved in the above compounds, and the balance of water (with the total amount being 100 wt.%).

Adsorption of dipolar (zwitterionic) surfactants to dipolar surfaces

Abstract: The adsorption of the neutral but dipolar (zwitterionic) surfactants, dodecyldimethyl(3-sulfopropyl)ammonium hydroxide and diheptanoic-sn-glycero-3-phosphocholine to the silicon nitride/water inter...

Reduction of nitrogen oxides

Abstract: A method is provided for reducing the nitrogen oxide content of a flue gas produced by the combustion of fuel by introducing a nitrogen oxide removal agent into either the nitrogen oxide contaminated flue gas or the fuel to be combusted The nitrogen oxide removal agent is the reaction product of a carbon compound in a pyrolysis liquor and a nitrogen compound such as ammonia, ammonium hydroxide or urea The carbon compound is selected from carboxylic acids, phenols, esters, aldehydes and ketones The pyrolysis liquor is derived from a feed stock containing cellulose, lignin or starch

Nonelectrolytic Production of Caustic Soda and Hydrochloric Acid from Sodium Chloride

Abstract: A nonelectrolytic process for the production of sodium hydroxide and hydrochloric acid from sodium chloride is explored. This environmentally friendly process, in which production of chlorine and the use of hazardous mercury are eliminated, is based on the following principle. A thermally stable cation exchanger such as ZSM-5 zeolite in its H-form undergoes a cation-exchange reaction with a sodium chloride solution to liberate hydrochloric acid, and the resulting NaZSM-5 zeolite undergoes a cation-exchange reaction with a ammonium hydroxide solution to liberate sodium hydroxide. The ammonium ion-exchanged zeolite is converted into its H-form by deammoniation in the temperature range of 400−500 °C. The liberated ammonia is trapped in water to form ammonium hydroxide for reuse.

Cleaning solutions for semiconductor devices

Abstract: Cleaning solutions for semiconductor devices comprise tetramethyl ammonium hydroxide, acetic acid, and water. Methods of removing contaminants from semiconductor devices comprise contacting the semiconductor devices with cleaning solutions to remove the contaminants from the semiconductor devices.

Preparation of ammonium glyphosate using aqueous ammonium hydroxide in a liquid-solid reaction system

Abstract: Solid N-phosphonomethylglycine or glyphosate acid is charged to a substantially closed system and then partially pre-dried as by continuously recirculating it through a hot air grinding/drying system. A cooled solution of ammonium hydroxide is then metered into and reacted with the partially dried glyphosate acid as it is being recirculated in a manner such that the moisture content of the reaction mass so formed is continuously decreased throughout the reaction. Following completion of the ammonium hydroxide addition, a powdered reaction mass/product having a moisture content of about 2 wt.% is formed. Significantly, at this stage, the ammonium glyphosate product is suitable for end use and it can be readily dissolved in water and immediately used as a herbicide or plant growth regulator. More importantly, however, this product is capable due to its highly sorptive character to be further formulated into a product exceptionally highly loaded with adjuvants and particularly surfactants.

Application of cobalt ammine complexes for the simultaneous determination of traces of As, Fe, Ti, V and Zr in high-purity cobalt metal by lanthanum hydroxide coprecipitation and inductively coupled plasma-atomic emission spectrometry.

Abstract: Co is not coprecipitated with lanthanum hydroxide in ammonium hydroxide solution due to the formation of soluble salts of cobalt ammine complexes. This complexation reaction has been applied to the simultaneous determination of five trace impurities (As, Fe, Ti, V and Zr) in high-purity Co metal by inductively coupled plasma-atomic emission spectrometry. Warming the solution and double coprecipitation are effective for separating the trace elements simultaneously from a large amount of cobalt ammine complexes. Matrix-matched solutions are used for calibration. The detection limits of the five elements are in the range of 0.06 and 0.6 μg/g and the recoveries are quantitative.

Oxidation catalyst, manufacture thereof and preparation of methacrylic acid

Abstract: PROBLEM TO BE SOLVED: To provide a heteropoly acid based catalyst having high reaction reactivity and selectivity and long catalytic life by producing an oxidation catalyst from an oxide containing phosphorus and molybdenum and a polyelemental oxide containing antimony together with one or more element selected from cerium, zirconium, etc. SOLUTION: This oxidation catalyst is a heteropoly acid type catalyst used for methacrylic acid production by gas-phase oxidation of methacrolein, t- butanol, etc., by bringing them into contact with molecular oxygen and the oxidation catalyst is produced from an oxide containing phosphorus, molybdenum, etc., and a polyelemental oxide containing antimony together with one or more element selected form cerium, etc. That is, solid substances obtained by drying a solution or a suspension produced by dissolving or suspending the catalyst raw materials in water are calcined at 150-300 deg.C and then the resultant calcined substances are kneaded with 0.2-0.8 times by wt. ammonia water containing 0.2-0.8 times by wt. water or 0.015-0.1 times by wt. ammonium hydroxide and after that, the polyelemental oxide is added.

Effective HPLC method for the determination of aromatic Amadori compounds

Abstract: An effective HPLC method was developed to separate and determine the phenylalanine, tryptophan, and tyrosine Amadori compounds in Maillard reaction mixtures. Using ammonium hydroxide as a major eluent component, the Maillard reaction mixtures of aromatic amino acid and glucose were separated in high resolution on an anion exchange column CarboPac PA-1. Aromatic amino acids and their Amadori compounds were determined by a UV detector at 260 nm. Glucose can be determined by a pulsed amperometric detector with the potentials and durations of E1 = 0.05 V (t = 360 ms) and E2 = 0.60 V (t = 120 ms). The effective gradient program was to increase the content of 0.5 mol/L sodium acetate from 0 to 100% in the 0.1 mol/L ammonium hydroxide solution. The separation was based on the acidity differences between the amino acid residues of amino acid and its Amadori compound. The method was simple and sensitive and was demonstrated to be applicable for the kinetic study of the Maillard reactions in aromatic amino acid and...

Calcium carbonate precipitation method

Abstract: A method for producing precipitated calcium carbonate by reacting an aqueous solution of calcium nitrate [Ca(NO3)2] with an aqueous solution of ammonium carbonate [(NH4)2CO3] and allowing calcium carbonate to precipitate from the resultant mixture containing nitrate [NH4NO3] in the mother liquor, the process being characterised in that: (i) the calcium nitrate [Ca(NO3)2)] solution utilised in the processes is prepared by slaking lime [CaO] in water in the presence of ammonium nitrate [NH4NO3] to form calcium nitrate [Ca(NO3)2] and ammonium hydroxide [NH4OH] in solution, filtering the solution to render it solids free, and heating the filtrate to dissociate the ammonium hydroxide [NH4OH] and to drive ammonia gas [NH3] from the solution; (ii) the ammonium carbonate (NH4)2CO3 solution utilised is prepared by absorbing ammonia gas [NH3] and carbon dioxide gas [CO2] in water, the ammonia gas preferably being derived from the step in (i) above in which the Ca(NO3)2 solution is heated; and (iii) the ammonium nitrate used is derived from the precipitation phase during which calcium carbonate is precipitated from the mother liquor containing ammonium nitrate.

Peeling liquid for resist film

Abstract: PROBLEM TO BE SOLVED: To obtain excellent peeling property and corrosion resistance by preparing a peeling liquid from water and at least one kind selected from among ammonium hydroxide, a quaternary ammonium hydroxide and an alkanolamine. SOLUTION: This peeling liquid for a resist film consists of an aq. soln. containing at least one kind selected from among ammonium hydroxide, a quaternary ammonium hydroxide and/or an alkanolamine. Thereby, the obtd. liquid has a function to peel a deposited film for protection of sidewalls of an etching pattern after a thin film of a ferroelectric material such as PZT is etched by using iridium or an iridium compd. as an electrode material. Further, if necessary, a sugar alcohol, a chelating agent and/or an org. solvent may be added to the soln. Thereby, noncorroding property for a wiring material is harmonized and the ability as a peeling liquid can be improved to peel a deposited film for protection of sidewalls of a resist pattern after a thin film made of a ferroelectric material containing a wiring material is etched.

Removal of Metal and Organic Contaminants from Silicon Substrates Using Electrolysis‐Ionized Water Containing Ammonium Chloride

Abstract: The efficiency of removing metal and organic contaminants from silicon substrate surfaces by using electrolysis-ionized water containing ammonium chloride was compared with the removal efficiency using an ammonium hydroxide and hydrogen peroxide mixture and a hydrochloric acid and hydrogen peroxide mixture. Before and after wet cleaning, metal impurities were measured using hydrofluoric acid vapor-phase decomposition atomic absorption spectrometry, and the organic impurities were measured using thermal desorption spectroscopy gas chromatography mass spectrometry. The electrolysis anode water removed both metal and organic contaminants due to its high oxidation-reduction potential and low pH. Oxidation and oxidative degradation are effective for the removal of both metal and organic contaminants from silicon substrate surfaces, and metallic complex acids are stable at low pH of the electrolysis anode water. The electrolysis cathode water, on the other hand, cannot remove metal or organic contaminants because of its high pH and low oxidation-reduction potential.

Method and composition for treating metal surfaces including dispersed silica

Abstract: A method and composition for treating metal surfaces to improve corrosion resistance and paint adhesion. The composition is a non-corrosive aqueous solution including water, a polymeric compound, an additive, and dispersed silica. In a preferred embodiment, the polymeric compound may be a polymer having a plurality of carboxylic functional groups and a plurality of hydroxyl groups. The polymeric compound may be a bifunctional copolymer or the reaction product of a first polymer having a plurality of carboxylic functional groups (e.g., polyacrylic acid or polymethylvinylmaleic anhydride), and a second polymer having a plurality of hydroxyl groups (e.g., polyvinyl alcohol). The additive is selected from at least one of: (i) an acid of a group IV-B element and a weak base, and (ii) an ammonium salt of a group IV-B compound such as ammonium zirconium carbonate. An exemplary acid of a group IV-B element is fluotitanic acid and an exemplary weak base is ammonium hydroxide. Dispersed silica is added, and any attack of the silica is minimized. The method for improving corrosion resistance and paint adhesion of a metal surface includes contacting the metal surface with a composition as described above and drying the composition in place. Prior to contacting the metal surface with such a composition, the metal surface may be cleaned and rinsed.

Method for etching an insulating material

Abstract: A method for etching aluminum containing layers. A layer (13) of aluminum nitride is formed on a semiconductor substrate (11). The layer (13) of aluminum nitride is etched using a dilute ammonium hydroxide solution that is diluted with water such that the ammonium hydroxide solution has one part of ammonium hydroxide to at least fifteen parts of water. The dilute ammonium hydroxide solution is showered onto the semiconductor substrate and forms an aluminum hydroxide layer. The aluminum hydroxide layer is dissolved by excess water in the dilute aluminum hydroxide solution and rinsed from the semiconductor substrate (11).

Process for manufacture of ultra-high purity ammonium hydroxide

Abstract: A process for obtaining an ultra-high purity aqueous ammonium hydroxide solution according to the invention includes the steps of reacting highly pure, typically electronics grade, ammonia (NH3) with ultrapure water (upw) under conditions effective to produce an ultra-high purity stream of aqueous ammonium hydroxide (NH4 OH) which is available for immediate use in a wide variety of applications especially those requiring high purity aqueous solutions of ammonium hydroxide.

Production of precipitated calcium carbonate

Abstract: A process for producing precipitated calcium carbonate having a particle size D50 of from 1 to 2 microns inclusive includes the steps of first contacting carbon dioxide gas with either ammonium hydroxide or with ammonia gas in the presence of water, to produce a solution of ammonium carbonate, and then contacting the solution of ammonium carbonate with a solution of calcium nitrate at a temperature below 58 °C and at a pH from 65 to 90 inclusive, optionally under pressure, to precipitate the calcium carbonate as a fine powder

Simultaneous determination of ammonium and nitrate in soils

Abstract: Continuous flow instrumentation for the automated measurement of ammonium and nitrate was developed at University of California, Davis. The method has been refined and adapted for routine analyses. Soil samples are extracted in 2N KC1 and the extracts are mixed with an alkali solution to liberate ammonia (NH3). The instrument has two channels for simultaneous measurements of ammonia and nitrate. Reduction of nitrates to ammonia takes place in one channel. The amount of ammonia in each channel is then measured by a diffusion‐conductivity method in which the ammonia gas is diffused through a micro‐porous Teflon tube and then redissolved in water to form ammonium hydroxide. The measured conductivity of the ammonium hydroxide is directly related to the ammonium content of the samples. The method is both rapid and reliable.

Polyphosphate Nanoparticles and Gels

Abstract: Amorphous metal (Al, Ca, Fe, Zr) polyphosphate particles and monolyths may be obtained in a range of chemical compositions, by admixture of aqueous solutions of sodium polyphosphate, metal salts and ammonium hydroxide.

Solid-phase extraction of the chromium(III)-diphenylcarbazone complex prior to ion-pair chromatography and application to geological samples.

Abstract: A method for the pre-treatment of acid samples prior to ion chromatography is described. In a strong acid medium, Cr(VI) oxidizes diphenylcarbazide, the resulting products forming a stable complex which can be transferred in a methanolic medium by solid-phase extraction using polyethylene as sorbent. This methanolic sample solution can be injected directly into a chromatographic system with a silica-based column. The separation and determination of the chromium complex can be performed by HPLC-using a mobile phase of 15% (v/v) acetonitrile containing 1 mmol/L tetrabutyl ammonium hydroxide (TBAH). The detection limit is estimated to be 2 μg/L chromate and the linear range is at least 0.05–2 mg/L chromate.

Process for the preparation of optically pure 1,2,3,4-Tetrahydro-3-isoquinoline-carboxylic acid and its derivatives

Abstract: This invention relates to the preparation of optically pure tetrahydro-3-isoquinolinecarboxylic acid derivative of formula (III) which comprises the reaction of optically pure phenylalanine derivative of formula (I) with a formaldehyde precursor, such as formaline, trioxane, dialkoxymethane, or paraformaldehyde, for about 10 hours to 60 hours at about 40 ° C. to about 60 ° C. in concentrated hydrochloric acid to give the compound of formula (II), followed by neutralization in hot water at about 70 ° C. to about 100 ° C. with a base, such as ammonium hydroxide, potassium carbonate, sodium carbonate, sodium hydroxide or potassium hydroxide, according to the following reaction scheme. ##STR1##

Synthesis and Reactions of Ethyl 6-Aryl-3-ethoxy-6-oxo-2, 4-hexadienoates

Abstract: Biologically interesting ethyl 6-aryl-3-ethoxy-6-oxo-2, 4-hexadienoates (1) have been prepared by the Witting reaction of [3-(ethoxycarbonyl)-2-ethoxy-2-propenylidene]triphenylphosphoranes (3a and 3b) and -arsorane (3c) with glyoxal monohydrates (5) and by oxidation of 6-aryl-3-ethoxy-6-hydroxy-2, 4-hexadienoate (9) with activated manganese (IV) oxide supported by silica. Reaction of 1a with 3c gave 3-(4-chlorobenzoyl)-1, 2-trans (and cis)-bis(1-ethoxy-2-ethoxycarbonylethenyl)cyclopropanes (6 and 7). When 1a was treated with a 1 : 5 mixture of concentrated HCl and tetrahydrofuran at room temperature, 3-hydroxy-6-oxo-2, 4-hexadienoate (10a) was obtained in 46% yield. Treatment of 1b with trifluoroacetic acid gave 5, 6-dihydro-2H-pyran-2-one (12) in 53% yield together with 10b in 28% yield. When 1a was treated with 1N ethanolic potassium hydroxide, 12 and 2H-pyran derivative (13) were obtained in 33% and 28% yields, respectively. Reaction of 1a with ammonium hydroxide and primary amines in the presence of a proton acid gave 2-oxo-1, 2, 5, 6-tetrahydropyridines (14) in good yields. The mechanism of the formation of 6, 12, 13, and 14 is discussed.

Methods for treatment of lead-containing surface coatings and soil

Abstract: A method is provided, to render non-hazardous, surfaces which are coated with lead-based paints. A composition comprising an aqueous mixture of hydrogen peroxide, ammonium hydroxide, nitric acid and acetic acid is poured on the surface and, after a time, water is poured onto the surface to remove the lead-based paint. The method is effective on surfaces which may be comprised of wood, metal, concrete, wallboard or plaster without destroying the integrity of these surfaces.

Method for preparation of ferrite powders at room temperature

Abstract: A method for precipitating ferrite at room temperature which involves dissolving metal salts in deaerated water, using a base solution to precipitate metal hydroxides, adding an oxidizing agent that has a standard reduction potential greater than 1.229 V versus standard hydrogen electrode. The oxidizing agent further preferably has a standard reduction potential less than 1.8 V versus standard hydrogen electrode. The oxidizing agent is preferably one of hydrogen peroxide, ammonium peroxydisulfate, ozone, nitrous acid, NO, and N 2 O. The base is preferably ammonium hydroxide.