Molecular Formula | C6H4Cl2 |
Molar Mass | 147.002 |
Density | 1.297g/cm3 |
Melting Point | -15℃ |
Boling Point | 180.5°C at 760 mmHg |
Flash Point | 65.6°C |
Water Solubility | 0.13 g/L (20℃) |
Vapor Presure | 1.21mmHg at 25°C |
Refractive Index | 1.548 |
Physical and Chemical Properties | Characteristics of colorless liquid flow, with flavor. melting point -15 ℃ boiling point 180.5 ℃ relative density 1.3022 refractive index 1.5501 flash point 71 ℃ solubility insoluble in water, it is miscible with ethanol, ether and benzene. |
Use | Mainly used in medicine, pesticide, organic synthesis, and as a solvent |
Hazard Symbols | Xn - Harmful N - Dangerous for the environment |
Risk Codes | R22 - Harmful if swallowed R36/37/38 - Irritating to eyes, respiratory system and skin. R50/53 - Very toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment. |
Safety Description | S23 - Do not breathe vapour. S60 - This material and its container must be disposed of as hazardous waste. S61 - Avoid release to the environment. Refer to special instructions / safety data sheets. |
UN IDs | UN 1591 |
colorless flowing liquid, aromatic, flammable. The relative density was 1. 3022. Melting Point -15 °c. Boiling point 180.5 °c. Refractive index 5501. Spontaneous ignition point was 647. 78 ℃. Insoluble in water, with ethanol, ether and benzene miscible.
prepared from chlorobenzene by-product and by synthetic methods.
Special Purpose Solution, remove carbon and lead on engine parts; As anti-rust agent, degreasing agent, remove metal surface coating without corrosion of metal; Paint solvent, the dye industry is used for the manufacture of reduced Blue CLB and reduced Blue CLG, etc.; Polymer wet spinning solvent, reduce the thermal shrinkage rate of fiber; Epoxy resin diluent, coolant, heat exchange medium; Also used for the preparation of pesticides, long-acting sulfonamides, etc.
introduction
dichlorobenzene mainly refers to p-dichlorobenzene and o-dichlorobenzene, which is an important fine chemical raw material. The nomenclature of the o-dichlorobenzene system is written as 1,2-dichlorobenzene, also referred to as o-DCB. After inhaling 1, 2-dichlorobenzene, respiratory irritation, headache, dizziness, anxiety, anesthesia, resulting in unconsciousness. Liquid o-dichlorobenzene and high-concentration o-dichlorobenzene vapor are irritating to the eyes and can be absorbed through the skin to cause poisoning, which is similar to inhalation. Oral administration causes gastrointestinal reactions. Skin contact can cause erythema and edema. Ortho-dichlorobenzene is flammable, toxic and irritating.
Preparation
78kg of benzene and 0.1kg of catalyst (5,10,15,20-tetraphenyl iron porphyrin) were added to the reaction device, and 145kg of chlorine was introduced to react. The reaction temperature was 70-120 degrees, the reaction pressure was 1-4 atmospheres, and the reaction time was 2-7 hours. Use a proper amount of water to absorb the hydrogen chloride gas generated by the reaction. The solution after the reaction is distilled to obtain a mixture of chlorobenzene and o-dichlorobenzene. The mixture is washed with a sodium hydroxide solution with a mass concentration of 5%, dried, and then rectified to obtain 135kg of o-dichlorobenzene with a purity of 99.5%. And a small amount of chlorobenzene. The residue in the reactor was directly used in the subsequent reaction, and the yield of o-dichlorobenzene was 98%.
chemical properties
colorless flowing liquid with fragrance. Insoluble in water, miscible with ethanol, ether and benzene.
use
production method
by-product of chlorobenzene and prepared by synthetic method. 1. Chlorobenzene by-product recovery Whether the benzene liquid phase chlorination method or the benzene gas phase oxychlorination method is used to produce chlorobenzene, dichlorobenzene is co-produced. According to the actual demand, the chlorination process conditions can be changed to adjust the production ratio of monochlorobenzene and dichlorobenzene. According to the current process control conditions and production conditions of chlorobenzene, the ratio of chlorobenzene to dichlorobenzene is 30-35:1. The industrial separation methods of ortho-and para-dichlorobenzene mainly include rectification and crystallization. 2. The o-chloroaniline and hydrochloric acid are added to the reaction pot by diazotization and replacement, and mixed evenly below 25 ℃. Cooling to 0 ℃, dropping sodium nitrite solution, maintaining the temperature at 0~5 ℃, until potassium iodide starch liquid turns blue, stop feeding, and obtain diazonium salt solution. Add cuprous chloride in hydrochloric acid solution at 0~5 ℃, stir and mix well, raise the temperature to 60~70 ℃, react for 1h, cool and stand for stratification, repeatedly wash the oil layer with 5% sodium hydroxide and water, dehydrate and fractionate with anhydrous calcium chloride, collect the fraction at 177~183 ℃, and obtain the finished product.
category pesticides
toxicity classification poisoning
acute toxicity oral-rat LD50: 500 mg/kg; oral-mouse LD50: 4386 mg/kg
stimulation data eyes-rabbit 100 mg/30 s mild
Explosive hazard characteristics Explosive when mixed with air
Flammability hazard characteristics Open flame is combustible; combustion produces toxic chloride smoke
Storage and transportation characteristics The warehouse is ventilated and dry at low temperature; stored separately from oxidants and food additives
fire extinguishing agent mist water, foam, carbon dioxide, sand
occupational standard TWA 300 mg/m3; STEL 450 mg/m3