Showing papers on "Phosphotungstic acid published in 1996"

Alkoxycarbonylnorbornyl (meth)acrylate, its production and photosensitive resin composition

Abstract: PURPOSE: To obtain a new alkoxycarbonylnorbornyl (meth)acrylate which is useful for a photosensitive resin composition giving a (formulated) cured product with reduced shrinkage in polymerization and curing and high adhesion to a variety of substrate materials, for example, a coating material of a type that is curable by irradiation with ultraviolet rays CONSTITUTION: This compound is represented by formula I (R is a 1-30C alkyl; R' is H, methyl), for example, butoxycarbonylnorbornyl acrylate The compound of formula I is prepared by Diels-Alder reaction between cyclopentadiene and an acrylic ester to form a compound of formula II followed by reaction of the adduct with (meth)acrylic acid in the presence of an acidic catalyst such as boron trifluoride or phosphotungstic acid

Collecting method of heteropoly acid

Abstract: PROBLEM TO BE SOLVED: To efficiently recover a heteropoly acid by bringing a water phase containing a heteropoly acid into contact with an org phase comprising an org solvent containing oil-soluble amine to transfer the heteropoly acid to the org phase, and then bringing the org phase into contact with the water phase to transfer the heteropoly acid to the water phase SOLUTION: When heteropoly acid in a water medium is to be recovered, in a first process, the water phase containing the heteropoly acid is brought into contact with an org phase comprising an org solvent containing oil-soluble amine In a second process, the org phase obtd in the first process is brought into contact with water The water phase after the heteropoly acid is transferred to the org phase in the first process is controlled to pH≤64, and the molar amt of the oil-soluble amine used is controlled to equal or higher than the acid equiv of the heteropoly acid In the second process, the water phase after the heteropoly acid is transferred to the water phase is controlled to pH≥71 As for the oil-soluble amine, aliphatic amine having ≥5 carbon atoms is used, and phosphotungstic acid is used for the heteropoly acid COPYRIGHT: (C)1998,JPO

The oxidation of penicillin-G-potassium salt using supported polyoxometalates with hydrogen peroxide

Abstract: The oxidation of the sulfide group in penicillin G potassium salt to the sulfoxide with hydrogen peroxide has been investigated using a wide range of polyoxometalates immobilized on high-surface-area supports. The highest activity and selectivity for the sulfur oxidation of the penicillin compound was obtained with ammonium molybdate supported on to strongly basic anion-exchange resin. The oxidation proceeds smoothly at ambient and sub-ambient temperatures in water or water/alcohol solvents. The use of supported oxidation catalysts has been extended to the transformation of benzenethiol to benzenesulfonic acid which was found to proceed in high yield and selectivity employing phosphotungstic acid on γ-alumina. The use of a supported catalyst with H2O2 as the primary oxidant allows the circumvention of environmental and product isolation problems to be overcome simply and economically.

Production of 1,2,3,4-butanetetracarboxylic acid

Abstract: PURPOSE: To obtain 1,2,3,4-butanetetracarboxylic acid repeatedly in high yield by efficiently separating and recovering a catalyst and reusing it in oxidizing tetrahydrophthalic acid anhydride with hydrogen peroxide. CONSTITUTION: Tetrahydrophthalic acid anhydride or its hydrous acid is oxidized by using hydrogen peroxide in the presence of a catalyst composed of tungstic acid, phosphotungstic acid or its salt and the reaction solution or a solution of a crude reaction product prepared by subjecting the reaction solution to solid-liquid separation is brought into contact with a weakly basic anion exchange resin to give 1,2,3,4-butanetetracarboxylic acid not containing the catalytic metal acid anion. The weakly basic anion exchange resin having adsorbed the anion is brought into contact with an alkali metal hydroxide or ammonium hydroxide and an aqueous solution containing the anion free from the reaction product is eluted and reused as the catalyst for the synthetic reaction. When the catalyst is reused, its pH is previously adjusted to <=2 with sulfuric acid.

Production of alpha-alkylstyrene oligomer

Abstract: PURPOSE:To provide a method for projection of alpha-alkylstyrene oligomers, especially trimer or more, capable of improving conversion to the oligomers of trimer or more and readily recovering and recycling the catalyst. CONSTITUTION:This method for production of alpha-alkylstyrene oligomers is carried out by reacting an alpha-alkylstyrene, e.g. a compound of the formula [R and R are each a 1 to 6C alkyl; (n) is 0 to 5] in the presence of a heteropolyacid, preferably silicomolybdic acid, phosphomolydbic acid, borotungstic acid, silicotungstic acid or phosphotungstic acid in a solventless solid-liquid heterogeneous system at 3 to 80 deg.C, especially 50 to 60 deg.C and preferably ordinary pressure to 10kg/cm . The amount of used catalyst is 0.5 to 100wt.%, especially 2 to 50wt.% based on the raw material. This method enables production of the alpha-alkylstyrene oligomers of trimer or more in a high yield although those oligomers can obtained only as a low-yield by-product in the conventional method.

High Performance Fuel Cell Based on Phosphotungstic Acid as Proton Conducting Electrolyte.

Abstract: A new low temperature fuel cell based on phosphotungstic acid electrolyte was realized. The electrochemical activity was investigated by polarization curves and lifetime experiments. An output electrical power of 700 mW cm−2 was obtained at 25 °C and 1 atm. Lifetime tests showed that the cell performance remained stable for prolonged periods of operation (more than 300 h). The influence of electrokinetic and mass transport parameters was investigated by digital simulation of the galvanostatic current-potential data. Cell performance is mainly determined by the high conductivity characteristics of the electrolyte and its promoting effect towards the oxygen reduction reaction.

Neutron Vibrational Spectroscopy of the H5O2+ Ion and Its Deuterated Analog in Phosphotungstic Acid Hexahydrate

Abstract: Heteropolyacid hydrates of the general form H 3 PM 12 O 40 . n H 2 O are of interest to researchers in areas such as proton conductivity and catalysis. The water molecules in these hydrated acids reside in the interstitial volume between the large Keggin anions and can, under certain conditions, complex with the acidic protons to form stable cations such as the “dioxonium” ion (H 5 O 2 + ). We have used incoherent inelastic neutron scattering (IINS) measurements of dodecatungstophosphoric acid hexahydrate (H 3 PW 12 O 40 · 6H 2 O) to obtain the vibrational density of states spectrum of H 5 O 2 + stabilized by the PW 12 O 40 3− Keggin anions. Spectra were measure for fully hydrogenated and fully deuterated ions in order to determine the relative merit of previous assignments of the normal mode vibrations.