Abstract: It is an object of the present invention to produce a cooking liquor containing polysulfide sulfur at a high concentration from white liquor in a pulp production process with a high selectivity at a low electric power with very little production of thiosulfate ions as by-product. The present invention provides a method for producing polysulfides, which comprises introducing a solution containing sulfide ions into an anode compartment of an electrolytic cell comprising the anode compartment provided with a porous anode, a cathode compartment provided with a cathode and a diaphragm partitioning the anode compartment and the cathode compartment, for electrolytic oxidation to obtain polysulfide ions, wherein at least the surface of said anode is made of nickel, and the porous anode has a physically continuous three-dimensional network structure.

Abstract: An agent for treating metal ions in an aqueous solution, which comprises an anthrahydroquinone compound and a metal supported on a carbonaceous carrier.

Abstract: A method for producing polysulfides, which comprises introducing a solution containing sulfide ions into an anode compartment of an electrolytic cell comprising the anode compartment provided with a porous anode, of which at least the surface is made of carbon, a cathode compartment provided with a cathode, and a diaphragm partitioning the anode compartment and the cathode compartment, and carrying out electrolytic oxidation to obtain polysulfide ions.

Abstract: Copper phthalocyanine is prepared by heating and reacting phthalic acid or a derivative thereof, urea or a derivative thereof and copper or a copper compound in the presence of molybdenum or a molybdenum compound as a catalyst and sulfur.

Abstract: A method for preparing a solution of an alkali salt of anthrahydroquinone, which comprises reacting a solution of an alkali salt of 1,4-dihydro-9,10-dihydroxyanthracene with anthraquinone in the presence of an alkali.

Abstract: A method for the treatment of waste water, which comprises treating waste water containing at least a sulfide-type malodorous substance, in the presence of a transition metal compound and hydrogen peroxide or a hydrogen peroxide-forming compound, wherein at least an iron family element compound and a vanadium family element compound are used as the transition metal compound.

Abstract: A method for producing copper phthalocyanine, which comprises heating and reacting phthalic acid or a phthalic acid derivative, urea or a urea derivative, and a copper compound, using molybdenum or a molybdenum compound as a catalyst, in the presence or absence of an inert organic solvent, wherein at least one compound selected from the group consisting of an aromatic dithiol compound of the following formula (I), a saturated aliphatic dithiol compound of the following formula (II), and their precursors, or at least one compound selected from the group consisting of a ruthenium compound and an osmium compound, is added to the reaction system: ##STR1##C.sub.m H.sub.2m-x R.sub.x (SH).sub.2 (II)wherein ring A in the formula (I) is a 6-membered single carbon ring or polycyclic condensed carbon ring aromatic compound, R for R.sub.n in the formula (I) or for R.sub.

Abstract: An agent for treating metal ions in an aqueous solution, comprising a solid porous carrier and, supported thereon, an organic reagent (hereinafter referred to as a "redox reagent") which is capable of converting metal ions (inclusive of metal complex ions) contained in an aqueous solution to zero valent metal or monovalent metal ions by a redox reaction and which is capable of carrying out oxidation-reduction reversibly.

Abstract: A 2-(1-alkylaminoalkyl)-3-hydroxy-1,4-naphthoquinone of the formula: ##STR1## wherein R.sup.1 is an alkyl group or a cycloalkyl group, and R.sup.2 is an alkyl group having at least 2 carbon atoms.

Abstract: A process for producing a copper phthalocyanine compound, which comprises heating and reacting phthalic acid or a phthalic acid derivative, urea or a urea derivative and cuprous chloride in the presence of a catalyst in an inert organic solvent, wherein the cuprous chloride is used in an amount of from 95 to 99% of the stoichiometric amount relative to the phthalic acid or the phthalic acid derivative.

Abstract: Naphthoquinone having a purity of higher than 95% is separated from an aqueous slurry of naphthoquinone and phthalic acid prepared by contacting, with an aqueous medium, a reaction mixture gas containing naphthoquinone and phthalic anhydride formed by a catalytic vapor phase oxidation of naphthalene. An extraction of naphthoquinone is carried out with a chain or cyclic saturated hydrocarbon at 60.degree. to 110.degree. C. under the condition adjusting pH to 1.2 to 5 and substantially dissolving phthalic acid in the aqueous phase and leaving resinous materials as a bottom.

Abstract: A 2-(1-alkylaminoalkyl)-3-hydroxy-1,4-naphthoquinone of the formula: ##STR1## wherein R.sup.1 is an alkyl group or a cycloalkyl group, and R.sup.2 is an alkyl group having at least 2 carbon atoms.The compounds are used in the preparation of a 2-(1-alkenyl)-3-hydroxy-1,4-naphthoquinone having insecticidal and fungicidal activity and a 2-alkyl-3-acyloxy-1,4-naphthoquinone having insecticidal and fungicidal activity and a 2-alkyl-3-acyloxy-1,4-naphthoquinone having miticidal activity.

Abstract: In a process for producing a metal phthalocyanine and/or its derivative by heating phthalic anhydride and/or its derivative, urea and a metal compound in an organic solvent in the presence of a catalyst, or by heating phthalodinitrile and a metal or a metal compound in an organic solvent, the improvement wherein the reaction for the production of the metal phthalocyanine and/or its derivative is conducted by an addition of cyanuric acid and/or its derivative.

Abstract: A process for producing 1,4-naphthoquinone by oxidizing naphthalene with molecular oxygen in a vapor phase in the presence of a catalyst. The catalyst is made of a mixture of a carrier and fusible catalytic components including vanadium oxide and alkali metal sulfate and pyrosulfate, and has a molded configuration having one or more through-holes.

Abstract: A method for molding 1,4,4a,9a-tetrahydroanthraquinone by cooling and solidifying a melt of 1,4,4a,9a-tetrahydroanthraquinone, which comprises contacting the melt with a cooling surface of a temperature of from about 50.degree. to about 80.degree. C. for solidification, and peeling off the solidified product.

Abstract: A process for removing an anthraquinone type scale comprises condensing a steam evaporated from a black liquor obtained by separating pulp from a digested mixture of lignocelluloses containing an anthraquinone type digesting assistant; and contacting a heated aqueous solution of a base in the presence or absence of a reducing agent or an alkali resistant surfactant with a wall of a condenser of an evaporator on which said anthraquinone type scale is adhered.

Abstract: A process for preparing a quinone, which comprises reacting a polynuclear aromatic hydrocarbon and a ceric salt in an aqueous acid solution in the presence of an organic solvent selected from the group consisting of chlorobenzene and an alkylbenzene represented by the general formula: ##STR1## where each of R.sub.1, R.sub.2 and R.sub.3 is an alkyl group and the total carbon number of the alkyl groups is from 3 to 6.

Abstract: A method for electrolyzing cerous sulfate in the electrolytic oxidation of cerous sulfate to ceric sulfate in an aqueous sulfuric acid solution, characterized in that the concentration of the cerous sulfate in the electrolyte to be supplied to the electrolytic cell is maintained, by the presence of ceric sulfate, at a level of at least the saturated concentration of cerous sulfate in the aqueous sulfuric acid solution (exclusive of the cerous sulfate and ceric sulfate) at the initial sulfuric acid concentration and at the temperature of electrolysis, and at most the saturated concentration of cerous sulfate in the presence of the ceric sulfate in the aqueous sulfuric acid solution at the initial sulfuric acid concentration and at the temperature of electrolysis, and the concentration of the ceric sulfate in the electrolyte is maintained at a level of at most the saturated concentration of ceric sulfate in the aqueous sulfuric acid solution at the initial sulfuric acid concentration and at the temperature of e

Abstract: A process for removing an anthraquinone type scale comprises condensing a steam evaporated from a black liquor obtained by separating pulp from a digested mixture of lignocelluloses containing an anthraquinone type digesting assistant; and contacting a heated aqueous solution of a base in the presence or absence of a reducing agent or an alkali resistant surfactant with a wall of a condenser of an evaporator on which said anthraquinone type scale is adhered.

Abstract: p-n-Alkylbenzoic acids having high purity without containing isomers are important as intermediates for liquid crystals. The p-n-alkylbenzoic acid is produced by reacting a p-formylbenzoic acid or its ester with a ketone having the formula ##STR1## wherein R represents a C.sub.1 -C.sub.18 n-alkyl or n-alkenyl group in the presence of a basic catalyst to obtain an unsaturated ketone compound having the formula ##STR2## wherein R is defined above and X represents hydrogen atom or a C.sub.1 -C.sub.