Jiangsu Sinorgchem Technology Co., Ltd.

Finings Co. Ltd.

Sinorgchem Company, Shandong

Shanghai Fanglun New Material Technology Co., Ltd.

Sinorgchem Shandong Co., Ltd.

Nongyue Wang

Xiaohui Mao

Xiaogen Feng

Qianwen Cheng

Ruibiao Yu

Quanzhong Zhao

Jianming Shao

Guoqiang Wen

Guohua Li

Xiongwei Qu

Luxin Wang

Renping Jiao

Qianwan Cheng

Disclosed herein is a method for aramid polymerization using carbon dioxide as a solvent, comprising reacting phenylenediamine with benzenedicarbonyl dichloride, wherein an acid-binding agent is added to the reaction system, and liquid carbon dioxide and/or a supercritical carbon dioxide fluid is used as a reaction solvent. The method of the present application is environmentally friendly, saves resources, has low cost, and is safe for production and suitable for industrial production. The polycondensate obtained in the present application has a controllable molecular weight, a good product quality, and an intrinsic viscosity ηinh of 8-9 dl/g. The yield in the aramid condensation stage can reach 98%, and the recovery rate of the aramid condensation solvent is higher than 90%.

Aramid polymerization method using carbon dioxide as solvent

A method for preparing chlorine gas through catalytic oxidation of hydrogen chloride is carried out by one-time hydrogen chloride feeding and multi-stage oxygen feeding, one-time oxygen feeding and multi-stage hydrogen chloride feeding, or both, returning a product gas stream without separation thereof, and optionally carrying out heat insulation means. In the present invention, excessive reaction heat concentration is prevented, therefore, the method of the present invention is a chlorine gas recovery method implemented through the Deacon catalytic oxidation of hydrogen chloride that may be industrialized.

Method for preparing chlorine gas through catalytic oxidation of hydrogen chloride

Clean process for preparing a chloroformyl-substituted benzene by oxidation of a tail gas hydrogen chloride from a chlorination reaction and a chloroacylation reaction and recycling of the resulting oxidation product chlorine gas into the chlorination reaction. The present invention provides a clean process for preparing a polymer-grade chloroformyl-substituted benzene.

Clean process for preparing chloroformyl-substituted benzene

The present application relates to a method for photochlorination, and specifically to photochlorination by a photochemical reaction of an aromatic compound with gaseous chlorine so as to prepare a trichloromethyl-substituted benzene, and to a method using bis-(trichloromethyl)-benzene as the trichloromethyl-substituted benzene to prepare by further reaction bis-(chloroformyl)-benzene. Through the control of temperature, illuminance and consumption of gaseous chlorine, the method of this application can greatly improve the purity of trichloromethyl-substituted benzene and further prepare polymer-grade bis-(chloroformyl)-benzene with low cost. The present application also relates to a method for purifying trichloromethyl-substituted benzene, and specifically to a method for purifying trichloromethyl-substituted benzene via molecular distillation. The present application further relates to a photochlorination reactor for use in photochlorination reactions (such as those of the present application).

Method for the preparation of trichloromethyl-group-substituted benzene

A process for preparing alkylated p-phenylenediamine having the steps of reacting aniline and nitrobenzene in presence of a complex base catalyst to obtain 4-aminodiphenylamine intermediates, hydrogenating the 4-aminodiphenylamine intermediates to 4-aminodiphenylamine in presence of a hydrogenation catalyst, and reductively alkylating the 4-aminodiphenylamine to alkylated p-phenylenediamine.

Process for preparing alkylated p-phenylenediamines

A method for refining an organic composition containing 4-aminodiphenylamine, aniline, azobenzene, and phenazine, having the steps of feeding the organic composition to a first rectification column, producing a first effluent composition containing aniline, azobenzene, phenazine, and a small amount of 4-aminodiphenylamine at the top of the first rectification column and a second effluent composition containing crude 4-aminodiphenylamine at the bottom of the first rectification column, feeding the second effluent composition to a second rectification column, and producing a 4-aminodiphenylamine composition at the top of the second rectification column and a residual composition at the bottom of the second rectification column.

Process for preparing 4-aminodiphenylamine

A falling film evaporator having a shell pass, multiple tubes parallel to each other, a condensed steam outlet, an inlet for an aqueous solution on the top of the tube pass, an outlet for the aqueous solution at the bottom of the tube pass, a distributing assembly having a plurality of distributing trays arranged vertically from top to bottom in incremental diameters and each having multiple holes, and a plate for collecting the aqueous solution below the distributing assembly. The tubes are straight and installed vertically in the evaporator; inner wall of the tubes is smooth, and the top portion of the tubes is protruded above a horizontal plane of the plate. The evaporator is particularly useful for concentrating an aqueous solution containing thermosensitive materials.

Falling film evaporator

The present invention provides spherical rubber chemicals and the method for preparing the same. The spherical rubber chemicals of the present invention include spherical antioxidants, spherical vulcanization agents, spherical processing aids, spherical reinforcing agents, or spherical adhesive agents. With the spherical rubber chemicals of the present invention, the shortcomings of powdery or semi-spherical rubber chemicals are overcome, including eliminating the dust pollution during granulation procedure and avoiding the raw material loss and the environmental pollution, while solving the quality problem of lower melting point of product caused by the presence of fine powder crystal. Furthermore, the resultant rubber chemicals has an improved smoothness of surface, which is helpful to improve the flowing and mixing behaviors of the rubber chemicals in mixing or open milling process with rubbers.

Spherical rubber chemicals and the method for preparing the same

A complex base catalyst comprising tetraalkyl ammonium hydroxide and tetraalkyl ammonium salt for the condensation reaction of aniline and nitrobenzene.

The present invention relates to a magnetic separation apparatus for continuous separating and recovering magnetic solid particles from a solid-liquid mixture. The apparatus includes at least one magnetic separation unit and each unit includes: an outer cylindrical vessel having a material inlet, a first outlet, and a second outlet; an inner cylindrical vessel, at least part of which extends along the axis inside the first cylindrical vessel without contacting with the inner surface of the outer cylindrical vessel; and a magnet, rendering the bottom of the inner cylindrical vessel magnetism during the first period and making the part of the surface lose its magnetism during a second period. When the solid-liquid mixture flows through the magnetic surface of the inner cylindrical vessel in the passage, the magnetic solids are absorbed and separated from the mixture.

Magnetic separation apparatus and method for recovery of solid material from solid-liquid mixture

A process for preparing 4-aminodiphenylamine having the steps of reacting nitrobenzene and aniline in the presence of a complex base catalyst, hydrogenating the reaction mixture with hydrogen, a powdery composite catalyst, and a hydrogenation solvent; separating, recovering, and reusing the complex base catalyst and the powdery composite catalyst from the reaction mixture; separating, recovering, and reusing aniline, and optionally water, from the reaction mixture; refining the reaction mixture to obtain 4-aminodiphenylamine. The complex base catalyst comprises tetraalkyl ammonium hydroxide, and tetraalkyl ammonium salt.

A process for preparing 4-aminodiphenylamine having the steps of reacting nitrobenzene and aniline in the presence of a complex base catalyst, hydrogenating the reaction mixture with hydrogen, a powdery composite catalyst, and a hydrogenation solvent; separating, recovering, and reusing the complex base catalyst and the powdery composite catalyst from the reaction mixture; separating, recovering, and reusing aniline, and optionally water, from the the reaction mixture; refining the reaction mixture to obtain 4-aminodiphenylamine. The complex base catalyst comprises tetraalkyl ammonium hydroxide, and tetraalkyl ammonium salt.

The present invention discloses a process for preparing 4-aminodiphenylamine, which process uses nitrobenzene and aniline as raw materials, a complex base catalyst as condensation catalyst and a powdery composite catalyst as hydrogenation catalyst, and comprises five process stages: condensation; separation I; hydrogenation; separation II; and refining. The process can be continuously carried out. By selecting a complex base catalyst to catalyze the condensation reaction and separating it prior to the hydrogenation, the problem that the complex base catalysts thermally decompose in the hydrogenation reaction is avoided, the selectable range of hydrogenation catalysts is largely enlarged so that it is possible to select cheaper hydrogenation catalyst, and the selection of production process and equipment is easier and further industrialization is easier. The complex base catalysts used in the present invention are inexpensive and have higher catalytic activity. The process can be carried out at mild conditions and can adapt to broad range of water content, by-product is less and conversion and selectivity are higher. The operational strength is low, no corrosive liquid is produced, and environment pollution is reduced. The purity of 4-aminodiphenylamine prepared can exceed 99 wt.-%, and the yield in the industrial production process can be over 95%.

A process for preparing 4-aminodiphenylamine using nitrobenzene and aniline as raw materials, a complex base catalyst as the condensation catalyst, and a powdery composite catalyst as the hydrogenation catalyst. The process has 5 process stages including condensation, hydrogenation, separation I, separation II, and refining.

Growing community of inventors

Shanghai, China

Nongyue Wang