Abstract: This invention relates to a process for the production of an alkanesulfionic acid such as isethionic acid with a high purity in a high yield and at a low cost by oxidation of a (hydroxy)alkylmercaptan with hydrogen peroxide characterized in that a whole amount beyond a stoichiometric amount of a solution of hydrogen peroxide having a H.sub.2 O.sub.2 concentration of not less than 50% by weight is charged into a reaction vessel, said mercaptan is continuously fed at a temperature of 50.degree. C. or lower, aging is carried out, distillation with boiling is carried out and then the reaction mixture is contacted with an anion exchanger.

Abstract: A stabilized sodium percarbonate is obtained by incorporating therein (A) at least one compound selected from the group consisting of mono- and dicarboxylic acids having not less than four carbon atoms and salts thereof; and (B) at least one compound selected from the group consisting of sulfates, nitrates and silicates of alkali metals and alkaline earth metals.

Abstract: A chemical solubilizing agent for tin or a tin alloy used for electroconductive materials is provided. Said chemical solubilizing agent is an acidic solution containing hydrogen peroxide and an inorganic acid and 0.5-50 g liter of said acidic solution of at least one nitrogen-containing compound selected from the group consisting of heterocyclic compounds not having a double bond in the respective heterocyclic rings, cyclopentylamines and cyclohexylamines.

Abstract: An acidic aqueous hydrogen peroxide solution containing copper can be stabilized by adding an amino acid having the formula ##STR1## wherein Ar is an aromatic group.

Abstract: Styrene oxide is prepared by reacting styrene and hydrogen peroxide in a heterogenous system in the presence of a bis(tri-n-alkyltinoxy) molybdic acid and an inorganic anion.

Abstract: A novel water-soluble produced by contacting thiourea dioxide with an aqueous solution comprising an amino acid having the general formula NH.sub.2 (CH.sub.2).sub.n COOH wherein n is an integer of 1 to 7 and a sodium, potassium or calcium salt of acetic acid.

Abstract: A crystallized, stable histidine-hydrogen peroxide adduct intermolecular-bonded at 1:1 ratio is provided.

Abstract: Metal ions contained in hydrogen peroxide can be removed efficiently, safely and inexpensively by contacting hydrogen peroxide to be purified with an anion exchange resin with a chelating agent adsorbed therein.

Abstract: Styrene oxide is prepared by reacting styrene and hydrogen peroxide in a heterogeneous system in the presence of a bis(tri-n-alkyltinoxy)molybdic acid and an amine represented by the following general formula: ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 each independently represent H, CH.sub.3, C.sub.2 H.sub.5, C.sub.3 H.sub.7, C.sub.4 H.sub.9, or HOCH.sub.2 CH.sub.2.

Abstract: An aqueous solution containing 0.1 g/l or more of piperidine or a derivative, 100-500 g/l of sulfuric acid, 10-50 g/l of hydrogen peroxide and 0.5 g/l or more of phosphoric acid is used for treating the surface of copper or copper alloy used in manufacturing of printed circuit.

Abstract: An amine-substituted thiourea dioxide is obtained by reacting thiourea dioxide and an aliphatic or aromatic primary amine in a neutral or acidic pH range.

Abstract: Activating thiourea dioxide is characterized by incorporating in the thiourea dioxide a substance which dissolves in water or an acidic aqueous solution and produces hydrogen.

Abstract: 4,4'-Dihydroxydiphenyl sulfone is isolated from a mixture of dihydroxydiphenyl sulfone isomers by heat dissolving the mixture in phenol and then cooling the resulting solution thereby allowing 4,4'-dihydroxydiphenyl sulfone to precipitate as an adduct with phenol.

Abstract: According to this invention, there is provided an improved method of dyeing fibrous products characterized in that, in the dyeing of fibrous products using an oxidation-reduction dyeing type dye and an aqueous alkali solution of thiourea dioxide as a reducing solution, the reduction of the dye with the said aqueous alkali solution of thiourea dioxide is carried out in the presence of one or more substances selected from the group consisting of saturated aliphatic ketones having 3 to 10 carbon atoms, saturated aliphatic ketocarboxylic acids having 3 to 10 carbon atoms and alicyclic ketones having 3 to 10 carbon atoms.

Abstract: According to this invention, there is provided a method of dyeing fibrous products characterized in that, in the dyeing of fibrous products using an oxidation-reduction dyeing type dye and an aqueous alkali solution of thiourea dioxide as a reducing solution, the reduction of the dye with the said aqueous alkali solution of thiourea dioxide is carried out in the presence of one or more dialdehyde compounds selected from dialdehyde compounds represented by the general formulaOHC--R--CHO (I)in which R is a saturated or unsaturated aliphatic or aromatic organic compound radical.

Abstract: According to this invention there is provided a method of recovering thiourea dioxide characterized in that in the production of thiourea dioxide by the reaction of thiourea and hydrogen peroxide in an aqueous solvent, the waste liquor after separation of the crystals of thiourea dioxide after reaction is treated with an ion-exchange resin to remove side reaction products and impurities contained therein, and is then concentrated with a reverse-osmotic membrane to crystallize the thiourea dioxide dissolved therein.

Abstract: According to this invention there is provided a process for preparing thiourea dioxide characterized in that in the production of thiourea dioxide by the reaction of thiourea and hydrogen peroxide in an aqueous solvent, ammonium bicarbonate is added to the reaction solution at a proper time.

Abstract: According to this invention there is provided a process for preparing thiourea dioxide characterized in that in the production of thiourea dioxide by the reaction of thiourea and hydrogen peroxide in an aqueous solvent, the filtrate after separation of the crystals of thiourea dioxide after reaction is treated with an ion-exchange resin to remove side reaction products and impurities contained therein and then is used again as a reaction solvent.

Abstract: According to this invention, there is provided a method of stabilizing an alkaline aqueous solution of thiourea dioxide characterized in that one or more substances selected from the group consisting of aliphatic ketones, alicyclic ketones and aliphatic dialdehydes are added to the said alkaline aqueous solution of thiourea dioxide.

Abstract: According to the present invention, there is provided a process for preparing pyrazines characterized in that a diol represented by the formula ##STR1## wherein R.sub.1 and R.sub.2 are each a hydrogen atom or a hydrocarbon radical, and a diamine represented by the formula ##STR2## wherein R.sub.3 and R.sub.4 are each a hydrogen atom or a hydrocarbon radical, are subjected to a gas phase contact reaction in the presence of a zinc-containing catalyst.