47 results about "1,2-Dichlorobenzene" patented technology

The invention relates to a method for preparing crude 1,6-hexamethylene diisocyanate through the phosgene method and separating pure 1,6-hexamethylene diisocyanate through rectification. The method uses o-dichlorobenzene and chlorobenzene as solvents and comprises the following steps: using hexanediamine and excessive phosgene to perform the two-step reaction of low temperature photochemical reaction and high temperature photochemical reaction under the action of catalyst and generate 1,6-hexamethylene diisocyanate (HDI), removing o-dichlorobenzene through distillation for reuse, continuously distilling to remove by-product chlorinated isocyanate, further mixing with DEIP solvent in a certain ratio through compulsory stirring, heating to perform flash evaporation and rectification, preparing the 1,6-hexamethylene diisocyanate product and DEIP through separation and purification, and regularly discharging the slagged tarry macromolecular compound to perform burning treatment.

The invention provides a novel process for preparing p-phenylene diisocyanate (PPDI) based on phosgene, which relates to a process for preparing chemical raw materials, in particular to a novel process for preparing the p-phenylene diisocyanate (PPDI). The process comprises the following steps: 1, hydrochloric acid formation reaction; 2, salifying reaction; and 3, photochemical reaction which is to transfer a mixture solution of para-phenylene diamine dihydrochloride-o-dichlorohenzene to a photochemical kettle, control the temperature, introduce the phosgene in an infinite reflux state to react, determine that the reaction is terminated after reaction materials are settled, introduce quantitative nitrogen to remove acid, sample and analyze the reactant, and obtain the p-phenylene diisocyanate PPDI through rectifying, crystallizing, centrifugating, drying, packaging or refining, slicing and packaging when the acidity content is qualified. In the process, a reasonable salifying reactioncondition is customized to avoid slow reaction of a prepolymer, complicated reaction mechanism, and easy generation of side products and adverse factors influencing the reaction in the next step.

Bis(halophthalimides) are prepared in mixture in an organic liquid such as ortho-dichlorobenzene or anisole, by a reaction at a temperatire of at least 150° C. between at least one diamine compound and at least one halophthalic anhydride in the presence of imidization catalyst. The reaction mixture is maintained at about 15% by weight solids content and rich in the halophthalic anhydride by constantly monitoring the reaction mixture using analytical methods such as high performance liquid chromatography. The product mixture may be directly employed in the direct preparation of polyetherimides, and similar slurries may be employed to prepare other polyether polymers.

The invention discloses a method for producing 2,4-dichloroacetophenone by using solid waste chlorobenzene tar as a raw material. The method mainly comprises the following steps of: extracting m-dichlorobenzene from the solid waste chlorobenzene tar, and then performing five steps of acylation, washing, distillation, crystallization and packing in the 2,4-dichloroacetophenone production process. The method is characterized in that: the acylation reaction comprises that: the m-dichlorobenzene and acetyl chloride undergo the acylation reaction under the action of anhydrous aluminum trichloride, the dripping temperature of the acetyl chloride is kept between 50 and 60 DEG C during reaction, the temperature is gradually raised to between 90 and 95 DEG C after the dripping is finished, and reflux stirring reaction is performed for about 4 hours to obtain the 2,4-dichloroacetophenone. The method has the advantages that: the m-dichlorobenzene is reclaimed from the solid waste chlorobenzene tar during production, and the reclaimed m-dichlorobenzene is used as the raw material for producing the 2,4-dichloroacetophenone, so by the method, the 2,4-dichloroacetophenone is produced by using the m-dichlorobenzene as the raw material while extra worries of m-dichlorobenzene and o-dichlorobenzene production enterprises are solved, the supply and demand pressure of chlorobenzene markets is relieved and extended products are further developed and utilized.

The present invention provides a method for preparing relatively insoluble bisimides under conditions which afford high imidization reaction rates and which permit the monitoring and adjustment of reactant stoichiometry at any stage of the reaction. The bisimides provided by the present invention are prepared either by reaction of a diamine such as 4,4′-diaminodiphenylsulfone (DDS) with an anhydride, for example 3-chlorophthalic anhydride (3-ClPA) in the presence of a solvent at a pressure greater than one atmosphere and at a temperature above the normal boiling point of the solvent, or by reaction of a monoamine with a dianhydride under the same conditions. In one embodiment, the relatively insoluble product bisimides provided by the present invention have a solubility in ortho-dichlorobenzene of less than about 10 percent by weight at a temperature of about 180° C.

The invention discloses an aqueous-phase synthesis method of chlorpyrifos by using trichloro-acetic chloride as an initial material. The method comprises steps of: reacting trichloro-acetic chloride, acrylonitrile, orthodichlorobenzene and a compound catalyst to obtain a 3,5,6-Trichloropyridin-2-ol sodium crude product; adding the 3,5,6-Trichloropyridin-2-ol sodium crude product into a reaction kettle with water, a catalyst and alkali, heating for reflux for 3 h, standing to separate out a solvent, and cooling, crystallizing and filtering an aqueous-phase to obtain the 3,5,6-Trichloropyridin-2-ol sodium; and adding water into the reaction kettle, adding a dispersing agent, 3,5,6-Trichloropyridin-2-ol sodium, ethyl chloride and a catalyst with stirring, reacting, cooling, crystallizing, washing and conducting suction filtration to obtain a chlorpyrifos active compound product. The invention employs trichloro-acetic chloride as the initial material to produce high-purity 3,5,6-Trichloropyridin-2-ol sodium, which is used directly as a raw material for the synthesis of chlorpyrifos. The sodium alkoxide produced by the method does not require refining, purifying or drying; water is used as the medium; and reaction materials are added at once for synthesis of chlorpyrifos. The method has advantages of simpleness, easy operation, environmental protection, energy saving, increased product yield, and improved product purity.

The invention discloses a method for preparing 3,4-dichlorophenyl isocyanate through continuous feeding reaction by using 3,4-dichloroaniline and phosgene as raw materials and using dichloroethane, methylbenzene, dimethylbenzene, chlorobenzene or o-dichlorobenzene as a reaction solvent. According to the method, hydrochloric acid gas generated in reaction can continuously generate 3,4-dichloroaniline hydrochloride together with 3,4-dichloroaniline, 3,4-dichloroaniline hydrochloride continues to react with phosgene at high temperature to remove hydrochloric acid and generate isocyanate, tail gas containing phosgene and the hydrochloric acid gas generated after reaction of each stage is fully utilized in reaction of next stage, and phosgene is utilized to the maximum extent. The method is safe and environment-friendly; in addition, the energy consumption of the whole process is low and the production efficiency is greatly improved.

The invention relates to a method for preparing maleimide stop end type polyimide resin, comprising the following steps: diamine, maleic anhydride and tetracarboxylic dianhydride are sequentially added to a polar solvent according to a molar ratio of (n+1):2:n to have the solid content of 25 plus or minus 1 percent (gram/milliliter) and then stirred for 8-24 hours at room temperature under the protection of nitrogen to generate intermediate polyamide acid, then a dehydrating agent acetic anhydride, a dehydrating catalytic agent triethylamine and the polar solvent are added into the intermediate polyamide acid so that the solid content is reduced to 15 percent (gram/milliliter) and then chemical imidization for 4-6 hours is conducted under the temperature of 30 DEG C-80 DEG C, then reaction liquid is poured into anhydrous ethanol which is stirred at high speed to obtain deposits, and the deposits are sequentially and sufficiently washed by the anhydrous ethanol and anhydrous ether and then dried in vacuum so as to obtain the maleimide stop end type maleimide polyimide resin, or heat dehydration cyclizing is conducted on the generated intermediate polyamide acid under the action of entrainer ortho-dichlorobenzene and chlorobenzene or methylbenzene to obtain outcomes of the maleimide stop end type maleimide polyimide resin.

The invention provides a method for preparing dichlorobenzene and trichlorobenzene and increasing the para-ortho ratio, and is characterized in that a chlorination reaction takes benzene or chlorobenzene as a raw material; a continuous chlorination reaction is carried out in the presence of a main catalyst and an auxiliary agent, through a ring type continuous chlorination reactor or a multi-stage series-connection kettle type reactor and under the conditions of the reaction temperature of 50-120 DEG C and the reaction pressure of -0.05-0.5 MPa; and a reaction liquid passes through a membrane filtration system, the main catalyst remains in the reactor for reaction, a dichlorobenzene clear liquid after filtration is subjected to light component removal, rectification and crystallization to obtain dichlorobenzene, orthodichlorobenzene, 1,2,3-trichlorobenzene and 1,2,4-trichlorobenzene finished products. Compared with a conventional dichlorobenzene preparation process, the method has the dichlorobenzene para-ortho ratio greatly increased to 8.5 and the trichlorobenzene para-ortho ratio greatly increased to 13.6, and has the advantages of low use cost of the catalyst auxiliary agent, continuous production realization, good product selectivity and the like.

The invention discloses a method and specially used apparatus for ortho-dichlorobenzene continuous mononitration reaction. The method is characterized in that raw materials are added into an ortho-dichlorobenzene metering tank; a nitrating agent A is added into a nitrating agent A metering tank; the raw materials and the nitrating agent A are separately input into a first mixer synchronously through a first metering pump and a second metering pump; a reaction is performed at a temperature of 100-200 DEG C for 15-50 min; a reaction solution A enters a first liquid separation device; after liquid separation, an organic phase A enters a second mixer and an inorganic phase A enters a waste acid receiving device; a nitrating agent B stored in a nitrating agent B metering tank is added into the second mixer through a third metering pump; a nitration reaction is performed in a second tube reactor at a temperature of 10-100 DEG C; a reaction solution B enters a second liquid separation device; after liquid separation, an inorganic phase B enters the waste acid receiving device and an organic phase B enters a product postprocessing device for obtaining a mononitration product. The concentration of sulfuric acid used in the preparation method provided by the invention is low, the raw material conversion is complete, the yield of the final product is high, multi-nitro by-products are less, and the safety is higher, so that the preparation method and the apparatus are suitable for industrialized production.

The invention relates to a method for synthesizing and preparing o-phenylenediamine from orthodichlorobenzene. The method for synthesizing and preparing o-phenylenediamine from orthodichlorobenzene comprises the following steps: putting orthodichlorobenzene, a copper catalyst and a ligand into an autoclave according to a molar ratio of 1:(0.25-5%):(0.25-5%), and then adding liquid ammonia or ammonia water into the autoclave, wherein the molar ratio of the added liquid ammonia or ammonia water to orthodichlorobenzene is (2-20):1; reacting for 2-36 hours while the reaction temperature is controlled to be 20-300 DEG C and the reaction pressure is controlled to be 1-10MPa; and finally, discharging while the inner temperature is controlled to be 90-100 DEG C, transferring into a distillation still, and carrying out vacuum distillation, so that white o-phenylenediamine is obtained. The method for synthesizing and preparing o-phenylenediamine from orthodichlorobenzene has the advantages that orthodichlorobenzene is taken as a raw material, direct amination is carried out to obtain o-phenylenediamine, a high power-supply ligand is adopted for improving the activity of the copper catalyst, the reaction difficulty is reduced, reaction conditions are mild, the reaction efficiency and reaction yield are obviously improved, and thus the method is applicable to industrial production.

The invention discloses a process for extracting high-purity m-dichlorobenzene from solid waste chlorobenzene tar, which is a process for extracting the m-dichlorobenzene from a mixture of m-dichlorobenzene, o-dichlorobenzene and p-dichlorobenzene separated from the solid waste chlorobenzene tar by adopting indirect adsorption of zeolite. The process comprises the following steps of: preparing mixed solution of alkanes, then separating a mixture of p-dichlorobenzene and o-dichlorobenzene by using the adsorption of the zeolite, and finally obtaining the m-dichlorobenzene. The process has the advantages that: the process for extracting the m-dichlorobenzene from the isomer mixture is an extraction process implemented by adopting a physical method, and the product obtained by the process hashigh purity and high yield.

The invention provides a process for preparing polycrystalline form oxytitamium phthalocyanine from the miscible liquidof orthodichlorobenzene and butyl alcohol which consists of the steps of, using orthodichlorobenzene and different volume ratio of butyl alcohol mixed liquid as crystal system modifier, charging purified oxytitamium phthalocyanine, agitating, elevating the temperature to 40-80 deg. C, stirring 4-8h again, cooling down and charging water as precipitating agent, methanol, ethanol or propanol solvent, stirring and filtering, washing the filter cake and drying.

The present invention discloses a permanent violet RL intermediate condensation product synthesis process, which comprises: alkylating carbazole to prepare N-ethyl carbazole, and carrying out nitrification and reduction to produce 3-amino-N-ethyl carbazole, and carrying out a condensation reaction in an organic solvent to obtain the permanent violet RL intermediate condensate. According t the present invention, the condensation reaction uses the alcohol solvent to replace the conventional o-dichlorobenzene, such that the conversion rate of 3-amino-N-ethyl carbazole is increased, the purity and the yield of the permanent violet RL crude product are improved, the process is stable, the operation is simple, and the safety coefficient is high.

The triethyl phosphite producing process with ethanol, phosphorus trichloride, o-dichloro benzene and N, N-dimethyl aniline as material includes the main steps of introducing ammonia, synthesis, water washing, layering, drying and distilling. It has sealed operation process, one distilling step, up reflux system and circular utilization of residual liquid and tail gas, and adopts enamel reactor, conic bottom water washing kettle, serially connected drying tower and other apparatus. The triethyl phosphate is used as plasticizer, stabilizer and additive in producing medicine, pesticide, plastic, dye and lubricant grease. The producing process has high yield, high product purity, no environmental pollution and low production cost.

The method for preparing polynorbornene by using novel bridged diimine nickel and palladium catalyst includes the following steps: firstly, adding main catalyst, then adding norbornene monomer solution, then adding solvent, finally adding catalyst promoter, the described main catalyst is the bridged diimine nickel and palladium compounding material, its concentration is 1X10 to the minus sixth-1X10 to the minus third mal/L, the described catalyst promoter is methyl aluminium-oxane, triethyl aluminium o r triisobutylaluminium, the mole ratio of the catalyst promotor and main catalyst is 1-10000, the solvent of the described norbornene monomer solution is methylbenzene, and the concentration of monomer in reaction system is 0.01-6.0 mol/L, the solvent of the described system i s methylbenzene, and its reaction temp. is 0 deg.C-90 deg.C.

The invention relates to methods and systems for preparing macrocyclic polyester oligomer (MPO) directly from monomer via heterogeneous catalysis, rather than by depolymerizing a polyester. For example, in an exemplary embodiment, cyclic poly(butylene terephthalate) (cPBT) is produced by reacting butanediol (BDO) and dimethylterephthalate (DMT) in an organic solvent—for example, ortho-dichlorobenzene (oDCB). The mixture flows over (or otherwise contacts) the catalyst-coated fiberglass or silica gel, e.g., which is packed in a column or bed. MPO is produced in the reaction mixture, while residual linears and catalyst residue remain in the column/bed.

The invention discloses a preparation technology of a solvent dye. O-dichlorobenzene is taken as a solvent, stannous chloride is taken as a catalyst, and condensation reaction is carried out on 1,4-dioxyanthraquinone and isopropylamine hydrochloride to prepare a target product. According to the preparation technology of the solvent dye, volatile solution isopropylamine is replaced with isopropylamine hydrochloride, the isopropylamine does not need to recycled, high-concentration nitrogen-containing wastewater cannot be generated, thereby reducing the difficulty of wastewater treatment; compared with an aqueous phase method, a solvent method is adopted to prepare 1,4-bi(1-isopropylamido) anthraquinone, and the wastewater quantity is sharply reduced; recrystallization is carried out on a mixed solvent of ethyl alcohol and petroleum ether, a sample of which the purity is 99.0% and the colored light is DC 0.5-1.5 specification can be prepared by adjusting a crystallization solvent, and thepreparation technology has a potential commercial prospect; the product yield can reach 92% or above, and the bulk density is 0.5 gram per cubic centimeter or above.