Sumitomo Chemical Company, Limited

Hiroshi Maki

Shigeru Sasaki

Tatsuyuki Mitsuno

Haruhisa Harada

Minoru Tabana

Yoshiaki Ito

Shizuo Narisawa

Michihiro Kawasaki

Hiroshi Shimizu

Horishi Shimizu

Masaaki Takenaka

A process for preparing an N-alkyl-substituted aminophenol is disclosed, comprising continuously feeding an aldehyde or a ketone to a reaction system containing an organic solvent, a catalyst for reduction, hydrogen, and an aminophenol to conduct a reductive alkylation reaction, wherein said reductive alkylation reaction is carried out while continuously adding an organic carboxylic acid into the reaction system. The process attains a high yield even when the catalyst is repeatedly used and does not cause corrosion of equipment.

Process for preparing N-alkyl-substituted aminophenols

A process for preparing an N-alkylaminophenol is disclosed, comprising subjecting an aminophenol to reductive alkylation with an aldehyde or a ketone in the presence of an organic solvent and hydrogen, wherein the reductive alkylation is carried out at a temperature of from 20.degree. to 70.degree. C. in the further presence of a catalyst for reduction comprising platinum and at least one metal element selected from metal elements belonging to the IB group, IIB group, IVB group, VB group, and VIB group of the Periodic Table, supported on activated carbon, or comprising palladium and at least one metal element selected from metal elements belonging to the IB group, IIB group, IVB group, VB group and VIB group of the Periodic Table, supported on activated carbon.

Process for preparing N-alkylaminophenols

A process for producing an N,N-diethylaminophenol is disclosed, comprising subjecting an aminophenol to reductive alkylation with acetaldehyde in the presence of a solvent, a catalyst, and hydrogen is disclosed, in which the reaction mixture from which the catalyst has been removed is subjected to distillation while maintaining the temperature of the bottom at 160.degree. C. or lower to substantially remove the unreacted acetaldehyde and the solvent, the residual bottom is distilled while maintaining the temperature of the bottom at 200.degree. C. or lower to recover a crude N,N-diethylaminophenol as a distillate, and the recovered crude N,N-diethylaminophenol is contacted with a solvent to which at least one of acid sulfites and dithionites has been added, said solvent being substantially incompatible with the N,N-diethylaminophenol, in an inert gas atmosphere, followed by precipitating and recovering the N,N-diethylaminophenol by cooling. N,N-Diethylaminophenols of high purity can be obtained in high yield without involving problems, such as production of large quantities of waste water and sludge, corrosion of materials, and coloring with time.

Process for producing N,N-diethylaminophenols

In a process for the production of an aminophenol which comprises reacting a divalent phenol and ammonia in the absence of a catalyst or in the presence of a water-soluble catalyst, then separating the reaction mixture after the reaction to recover a separated and recovered product containing an aminophenol and the unreacted divalent phenol, and separating and purifying the aminophenol from said separated and recovered product, the process for the production of an aminophenol which is characterized by, on separating and purifying said aminophenol, contacting said separated and recovered product with an aliphatic ether substantially incompatible with said aminophenol in an inert gas atmosphere at a temperature at which said separated and recovered product melts or higher, then cooling to induce the crystallization of the aminophenol, thereafter filtering and recovering to obtain a cake mainly composed of said aminophenol, further melting and contacting this cake with an aliphatic ether in an inert gas atmosphere in the co-presence of water and a surfactant, and then cooling to induce the crystallization of said aminophenol and recovering it. According to the invention, a high-quality aminophenol can be produced.

Process for the production of an aminophenol

A method for producing an aromatic carbonyl compound represented by the formula (B)-1 or (B)-2: ##STR1## comprising decomposing a hydroperoxide represented by the formula (A)-1 or (A)-2: ##STR2## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are defined in the specification, in an inert gas atmosphere in the presence of an aqueous layer containing an iron salt, a copper salt and an acid is disclosed. Novel m-(2-hydroxy-2-propyl)acetophenone and m-isopropenylacetophenone which are useful as an intermediate for the preparation of medicines are also disclosed. A method for producing m-isopropenylacetophenone comprising dehydrating m-(2-hydroxy-2-propyl)acetophenone in the presence of an acid catalyst is further disclosed.

Method for producing aromatic carbonyl compounds

Dihydric phenol is effectively prevented from discoloration by mixing the dihydric phenol with 0.00001 to 0.1% by weight of hydrocarboxylic acid on the basis of the dihydric phenol.

Method for preventing the discoloration of dihydric phenols

A rubber-modified polystyrene resin composition consisting essentially of a rubber-modified polystyrene and a transparent, resinous styrene-butadiene block copolymer containing 65 to 95% by weight of styrene and 5 to 35% by weight of butadiene. This resin composition is excellent in impact strength, elongation, flexural stress clouding, hinging endurance, and surface gloss.

Rubber-modified polystyrene resin composition

A novel thermoplastic resin composition consisting essentially of polystyrene and a styrene-butadiene block copolymer. This resin composition is transparent, is excellent in mechanical properties, particularly in elongation, impact strength, and stiffness, is not liable to become cloudy on being bent, and is favorable in hinging endurance as well as in thermal resistance.

Thermoplastic resin composition

A resin composition consisting essentially of a styrene-butadiene block copolymer resin, a liquid polybutadiene resin or its modification product, and a tackifier. This resin composition is transparent, excellent in mechanical properties, particularly elongation, impact strength and elastic recovery, and is also improved in film-forming ability and tackiness.

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Chiba, Japan

Hiroshi Maki