Plastic, Rubber
Do you have questions?
We unleash your business potential by maximize the business innovation.
Send EmailXylene mixture (m-xylene, o-xylene, p-xylene), Xylene, OVEN THINNER / XYLENE, Xylene mixture of isomers, Xylol , Xylene Low Cumene, Xylene (isomeren), Xylene solvent, 1330-20-7
CAS: 1330-20-7
Molecular Formula: C8H10
Names and Identifiers
| Name | Xylene mixture (m-xylene, o-xylene, p-xylene) |
| Synonyms | ai3-02209-x Total xylenes Xylene (mixed) m-,p-,o-Xylene o-,m-,p-Xylene Xylene mixture SEALIT SEALANT Xylenes (mixed) Xylene, (total) NAPHTHA SOLVENT benzene,dimethyl- Xylene (o-,m-,p-) SCINTILENE COCKTAIL Xylenes mixed isomers SCINTIVERSE I COCKTAIL SCINTIVERSE E COCKTAIL Xylene (mixed isomers) Xylene (o-, m-, p-isomers) Socal aquatic solvent 3501 Dimethylbenzene (mixed isomers) except p-xylene, mixed or all isomers xylene, mixed or all isomers, except p- Xylene mixture (m-xylene, o-xylene, p-xylene) |
| CAS | 1330-20-7 |
| EINECS | 215-535-7 |
| InChI | InChI=1/4C8H10/c1-7-3-5-8(2)6-4-7;1-7-4-3-5-8(2)6-7;1-7-5-3-4-6-8(7)2;1-2-8-6-4-3-5-7-8/h3*3-6H,1-2H3;3-7H,2H2,1H3 |
| InChIKey | KAKOUNRRKSHVJO-UHFFFAOYSA-N |
Physico-chemical Properties
| Molecular Formula | C8H10 |
| Molar Mass | 106.17 |
| Density | 0.86 g/mL at 25 °C (lit.) |
| Melting Point | -34 °C |
| Boling Point | 137-140 °C (lit.) |
| Flash Point | 77°F(lit.) |
| Vapor Presure | 18 mm Hg ( 37.7 °C) |
| Vapor Density | 3.7 (vs air) |
| Appearance | Liquid |
| Color | APHA: ≤10 |
| Exposure Limit | ACGIH: TWA 100 ppm; STEL 150 ppmOSHA: TWA 100 ppm(435 mg/m3) |
| Merck | 14,10081 |
| BRN | 1901563 |
| Storage Condition | Flammables area |
| Explosive Limit | 7% |
| Refractive Index | n20/D 1.497(lit.) |
| Physical and Chemical Properties | The
trait was a mixture of P-xylene, O-xylene, M-xylene and ethylbenzene. Colorless transparent liquid. |
| Use | Widely used as organic solvents and synthetic medicines, coatings, resins, dyes, explosives and pesticides and other raw materials |
Risk and Safety
| Risk Codes | R10 - Flammable R20/21 - Harmful by inhalation and in contact with skin. R38 - Irritating to the skin R36/38 - Irritating to eyes and skin. R65 - Harmful: May cause lung damage if swallowed R48/20 - |
| Safety Description | S25 - Avoid contact with eyes. S36/37 - Wear suitable protective clothing and gloves. S62 - If swallowed, do not induce vomitting; seek medical advice immediately and show this container or label. |
| UN IDs | UN 1307 3/PG 3 |
| WGK Germany | 2 |
| RTECS | ZE2100000 |
| TSCA | Yes |
| HS Code | 29024400 |
| Hazard Class | 3 |
| Packing Group | II |
| Toxicity | LD50 oral in rat: 4300mg/kg |
Upstream Downstream Industry
| Raw Materials | Sulfuric acid Sulfuric acid Sodium hydroxide Naphtha (petroleum), light alkylate |
| Downstream Products | Ethylbenzene Toluenediisocyanate bornan-2-one Maleic anhydride alpha,alpha'-diamino-P-xylene xylidine mixture of isomers Fenbutatin oxide |
Nature
colorless transparent liquid. A mixture of three isomers (para, Ortho, Meta) and ethylbenzene. With ethanol, ether, chloroform and other organic solvents miscible, insoluble in water.
Use
for the determination of moisture in compounds. Solvents and cleaning agents for precision optical instruments and the electronics industry.
Preparation Method
The mixed benzene of the light petroleum fraction was purified by hydrogenation, and was subjected to catalytic reforming to obtain xylene. Or coking crude benzene by washing, fractionation and obtained.
Safety
- This product has moderate toxicity. The percutaneous absorption was minimal. After harvest, the impact on health is much smaller than that of benzene. The LC of xylene vapor to mice was 6000 x 10-6, and the minimum oral lethal dose to rats was 4000mg/kg.
- for the packaging and storage of this product, see benzene. Packing, marking, storage, transportation and delivery acceptance shall be carried out according to zbe30005.
Reference Information
| LogP | 3.16 at 20℃ |
| (IARC) carcinogen classification | 3 (Vol. 47, 71) 1999 |
| Overview | xylene is a colorless, transparent and aromatic liquid, it is a product in which two hydrogens on the benzene ring are substituted by methyl groups, and the boiling point is 137~140 ℃. Xylene is divided into three isomers, O-xylene, M-xylene and p-xylene, according to the different positions of the two methyl groups, xylene refers to a mixture of the above isomers and ethylbenzene. Grade water is generally 3 ℃ and 5 ℃ distillation range of high-grade products and first-grade products. With ethanol, chloroform or ether can be mixed at will, insoluble in water. Widely used in organic solvents and the synthesis of medicines, coatings, resins, dyes, explosives and pesticides. Xylene moderate toxicity, but also a certain carcinogenicity. Xylene pollution mainly comes from synthetic fiber, plastic, fuel, rubber, various coating additives and various adhesives, waterproof materials, but also from fuel and tobacco combustion gas. |
| xylene isomer | xylene is an aromatic hydrocarbon in which two hydrogen atoms on the benzene ring are substituted by two methyl groups. In the coking industry, it is one of the refined products of crude benzene. Xylene insoluble in water, soluble in ethanol and ether and other organic solvents. There are three kinds of xylene isomers, namely, O-xylene, M-xylene and p-xylene, and ethylbenzene, which has the same elemental composition as xylene, is also its isomer. Their molecular formula is C8H10, the molecular weight is 106.16, and other physical properties are different. The chemical properties of ortho-, meta-and para-xylene were similar. Side chain alkyl can be oxidized under the action of catalyst, M-xylene, p-xylene to produce phthalic acid, O-xylene to produce dimethyl anhydride. It reacts with ammonia and oxygen to form phthalonitrile. O-xylene, M-xylene and p-xylene can be isomerized with each other. At the time of heat-condensation, poly-P-dimethylbenzene is formed. The aromatic ring of the three can also undergo electrophilic substitution reaction under the action of catalyst. Both of them can form complexes. All three were combustible. It is irritating to eyes and skin. Low concentration can cause Head Pain, high concentration of anesthesia. The maximum allowable concentration in the workplace is 100 × 10-6. |
| organic chemical raw materials | xylene is an important organic chemical raw materials, there are three kinds of isomers, O-Xylene is mainly used for the preparation of phthalic anhydride, which is an important raw material for the manufacture of a variety of dyes and indicators (such as phenolphthalein). 4, 6-dimethyl-1, 3-phenylenediamine produced by nitration and reduction of M-Xylene is an intermediate for the synthesis of dyes, and M-xylene can also be used as a raw material for the synthesis of fragrances (such as Musk xylene). P-xylene is mainly used in the manufacture of terephthalic acid, which is an important raw material for the synthesis of polyester fiber (polyester). xylene is present in coal tar and certain petroleum oils. The extraction of the C8 fraction in the naphtha reformate is industrially the main one. Industrial xylene contains 50% ~ 60% M-xylene, and O-and p-xylene each account for 20% ~ 25% (volume). Xylene can be directly used as a solvent without separation, and can be added to gasoline to improve the Antiknock, which is a component of aviation gasoline. The boiling point of O-Xylene is relatively high, which can be separated by distillation. The melting point of p-xylene is relatively high, and the purification is carried out by fractional crystallization. xylene is also present in coking crude benzene and petroleum cracked oil. Crude benzene by preliminary distillation, sulfuric acid washing and distillation, separation of benzene and toluene, and then by distillation can be obtained xylene, also known as coking xylene. The quality of coking xylene depends on the separation capacity, overhead temperature and reflux ratio of the rectification column. China will be coking xylene products are divided into three levels. China coking xylene technical index Reference: Wu Yongren, editor-in-chief. Chemistry Volume, Encyclopedia of Chinese middle school teaching. SHENYANG: Shenyang Publishing House. 1990. Page 247. |
| comparison of benzene, toluene, xylene | benzene and its homologs toluene, xylene are mainly obtained from the fractionation of coal tar and cracking of petroleum. The three are colorless, transparent and aromatic liquid, highly volatile. Industrial use of the three different boiling point and its separation. But in general, it is difficult to separate the three completely. Therefore, general industrial benzene contains a considerable amount of toluene and xylene, industrial toluene also contains a considerable amount of benzene. Therefore, in the production environment Air, benzene, toluene, xylene often exist at the same time. Coal tar fractionation and oil cracking can contact benzene, toluene, xylene; These three are mainly used as organic solvents and chemical raw materials. Rubber, paint, paint, pharmaceutical, synthetic fiber (polyester), dyes, pesticides, artificial leather production and printing industry can be exposed to benzene. Toluene is less toxic than benzene. In recent years, it has been used to replace benzene as a solvent for rubber and resin, as well as a diluent for paint, paint and ink. It is also used in explosive, pharmaceutical and other chemical production. Xylene is less toxic than toluene, and is used as a solvent for paint, pesticide, and a substitute for benzene and toluene. |
| preparation of xylene by sulfonation | mixed fraction of M-xylene and p-xylene (I. E. Mixed xylene fraction) reacts with concentrated sulfuric acid, A method of selectively sulfonating meta-xylene to separate meta-xylene and para-xylene. The mixed xylene fraction is contacted with concentrated sulfuric acid, and M-Xylene is selectively sulfonated at 30-35 ℃ to form M-xylene sulfonic acid: p-xylene does not undergo sulfonation reaction. After hydrolysis, neutralization and rectification of the separated m-xylene sulfonic acid, M-xylene with a purity of 95-98% can be obtained. The non-sulfonated substance containing p-xylene was neutralized with a base and crystallized to obtain p-xylene with a purity of 95%. flow chart for separation of xylene by sulfonation |
| crystallization method | a mixed xylene fraction containing m-xylene and p-xylene is eutectic CRYSTALLIZED (crystallization temperature -53.1 °c), A eutectic containing 12.5% of p-xylene and 87.5% of M-xylene was obtained, and the two products were separated by secondary crystallization. The crystals obtained by the first crystallization and filtration are commercial-xylene. When the filtrate is crystallized for the second time, an appropriate amount of carbon tetrachloride is added, which can form a solid complex with p-xylene at an initial crystallization temperature of -40 °c, A solid complex with an initial crystallization temperature of -78 °c is formed with M-xylene. The crystallization temperature was controlled to crystallize only carbon tetrachloride and p-xylene. The crystals obtained by filtration were melted, and carbon tetrachloride was separated by distillation to obtain p-xylene. After carbon tetrachloride was recovered from the filtrate by distillation, M-xylene was obtained. The carbon tetrachloride in the process is recycled. |
| toxicity and harm to human health | xylene has moderate toxicity. After absorption through the skin, the effect on health is much smaller than that of benzene. If the accidental oral xylene or xylene solvent containing, namely strong irritation of the esophagus and stomach, and cause Vomit, may also cause bloody Pneumonia, should immediately drink liquid paraffin, the doctor for diagnosis and treatment. The LC of xylene vapor to mice is 6000*10-6, and the minimum oral lethal dose to rats is 4000mg/kg. Xylene has a stimulating effect on the eye and upper respiratory tract, and has an anesthetic effect on the central system at high concentrations. Acute poisoning: short-term inhalation of higher concentrations of this product can appear eye and upper respiratory tract irritation symptoms, conjunctival and pharyngeal congestion, dizziness, Head Pain, Nausea, chest tightness, weakness, confusion, gait. Severe cases may have irritation, convulsions or Coma. Some had hysteria-like episodes. Chronic Effects: Long-term exposure to neurasthenia syndrome, women may lead to abnormal menstruation. Skin contact often occurs dry skin, chapped, dermatitis. |
| metabolism and degradation | in humans and animals, except 3~6% of inhaled xylene is directly exhaled, all three isomers of xylene are metabolized to the corresponding benzoic acids (60% o-xylene, 80%-90% m-p-xylene), which are then reacted with glucuronic acid and glycine. In this process, a large amount of O-benzoic acid is combined with glucuronic acid, while P-benzoic acid must be completely combined with glycine to form the corresponding methyl hippuric acid and excreted from the body. At the same time, a small amount of the corresponding xylenol (phenol) and hydrogenated 2-methyl-3-hydroxybenzoic acid (2% or less) may be formed. |
| residue and accumulation | During occupational exposure, xylene enters the body mainly through the respiratory tract. For all xylene isomers, the absorption of their vapor by the lungs is the same, with a total of 60% to 70%, which is relatively constant throughout the exposure period. Xylene solution can be absorbed through intact skin with an average absorption rate of 2.25 µg/(cm3 · min)(range 0.7~4.3 µg/(cm3 · min)), percutaneous absorption of xylene vapor is negligible compared to direct contact with liquid. The residue and accumulation of xylene is not serious. We have said that xylene entering the human body can generate methylbenzoic acid in the presence of NADP (transferase II) and NAD (transferase I), then combined with glycine to form methyl hippuric acid, almost all of which were excreted in 18 hours. Even 3-6% of xylene remaining in the lungs after inhalation is exhaled within 3 hours after exposure (half-life of 0.5-1 hour). To evaluate the residual test of exposure to xylene, mainly to determine the content of methyl hippuric acid in urine, It has also been suggested to determine the content of xylene in the gas or blood, but the latter results are often not accurate. Since methylhippuric acid is not naturally present in the urine, and since it is almost entirely a retained xylene metabolite, the determination of its presence is the best confirmation of the xylene exposure test. Xylene can be found in drinking water for a relatively long time. When the concentration of xylene in tap water is 5mg/L, the odor intensity is equivalent to grade 5, and the characteristic odor of xylene will disappear in 7 to 8 days; when the odor intensity is 3, it takes 4 to 5 days. The smell of xylene in the river water is kept for a short time, which is related to the initial concentration, and can be retained for 3 to 5 days. |
| migration and transformation | xylene is mainly produced from crude oil in petrochemical process, it is widely used in pigment, paint and other diluents, solvents for the printing, rubber, and leather industries. As a detergent and grease remover, a component of aviation fuel, raw materials and intermediates for chemical plants and the synthetic fiber industry, as well as for the coating and impregnating of textile paper. Xylene can cause pollution by mechanical ventilation and ventilation equipment into the atmosphere. A refined refinery emits up to 13.18~1145G/h of xylene into the atmosphere. Xylene can enter the water body with the waste water discharged from its production and use unit to produce 1 ton of xylene, generally, 2 cubic meters of wastewater containing 300 ~ 1000mg/L of xylene are discharged. Due to the strong trend of xylene Volatilization in aqueous solution, it can be considered that it is not a persistent pollutant in surface water. Xylene is also biodegradable in the environment, but the rate of this process is much lower than the rate of the volatile process. Xylene volatilized into the air may also be photolyzed, which is its main migration and transformation process. Xylene is excreted from the human body by exhalation and metabolites at a rapid rate, almost all of which are excreted within 18 hours of contact Cessation. Xylene can be found in drinking water for a long time. Due to the strong volatility of xylene in aqueous solution, it can be considered that it is not a persistent pollutant in surface water. Xylene in the environment can also be biodegradable and chemical degradation, but its rate is much lower than volatile, volatile xylene into the air can be photolyzed. Can react with the oxidant, high concentration of gas and air mixed explosion. Xylene has a moderate risk of combustion. Since its vapor is heavier than air, the flame diffuses along the ground during combustion. Xylene is easy to volatilize, and the accident will be diffused with the special aromatic taste of xylene. The xylene in the poured water can float on the water surface or be distributed in the water surface, can cause the death of fish and aquatic organisms. |
| National Standard | China (TJ36-79) maximum allowable concentration of hazardous substances in the air of workplace of 100mg/m3 (xylene) china (TJ36-79) the maximum allowable concentration of harmful substances in the atmosphere of residential area 0.30mg/m3 (a value, xylene) China (GB16297-1996) air pollutant emission standard (xylene) ① maximum allowable emission concentration (mg/m3):70 (Table 2);90 (Table 1) ② maximum allowable emission rate (kg/h): grade II: 1.0-10 (Table 2);1.2-12 (Table 1); Grade III: 1.5-15 (Table 2);1.8-18 (Table 1) ③ monitoring concentration limits of unorganized emissions: 1.2mg/m3 (Table 2);1.5mg/m3 (Table 1) China (to be promulgated) the maximum allowable concentration of harmful substances in drinking water sources 0.5mg/L (xylene) china (GHZB1-1999) surface water environmental quality standard (I, II, III waters specific value) 0.5mg/L (xylene) China (GB8978-1996) Integrated Wastewater Discharge Standard Class I: 0.4mg/L Grade II: 0.6mg/L grade III: 1.0mg/L |
| uses | widely used as organic solvents and synthetic medicines, coatings, resins, dyes, explosives and pesticides and other raw materials used as cleaning agent solvent, determination of moisture in many organic compounds, microscope cleaner. Cleaning agents for silicon components and thermistors. Mixed xylene is a mixture of Ortho; Meta; Para-xylene and ethylbenzene. When used as a chemical raw material, each isomer may be separated in advance. The mixture is mainly used as a solvent for paint coatings and as an additive for aviation gasoline. |
| production method | 1. Recovery of benzene from coking by-products high temperature tar from high temperature coking by-products contains a part of benzene. First of all, the initial distillation column, the top of the light benzene, heavy benzene at the bottom of the column (heavy benzene is used as a raw material for the preparation of coumarone resin). The light benzene is first separated by an initial distillation column, and the mixed fraction at the bottom of the column is washed with acid and alkali to remove impurities. Then it is steamed and blown in a benzene blowing column, and then distilled by a rectification column to obtain pure benzene. 2. The light gasoline (initial distillation point is about 138 ℃) obtained by the atmospheric distillation of platinum reforming method, and the fraction of more than 65 ℃ is cut off. The harmful impurities are removed by catalytic hydrogenation of the molybdenum-containing catalyst, and then reformed by the platinum catalyst, extraction with a diethylene glycol ether solvent followed by column-by-column distillation yields the products of benzene, toluene, xylene, etc. |
| category | flammable liquid |
| toxicity grade | poisoning |
| Acute toxicity | oral-rat LD50: 4300 mg/kg; Oral-mouse LD50:2119 mg/kg |
| stimulation data | Skin-rabbits 500 mg/24 h moderate; eye-rabbit 5 mg/24 h severe |
| explosive hazard characteristics | explosive when mixed with air |
| flammability hazard characteristics | flammable in open flame, high temperature, strong oxidant; combustion-induced smoke |
| storage and transportation characteristics | The package is complete, light and light unloading; The warehouse is ventilated, away from open flame, high temperature, separate from oxidant |
| fire extinguishing agent | foam, dry powder, carbon dioxide, sand |
| Occupational Standard | TWA 435 mg/m3; Tel 750 mg/m3 |
| spontaneous combustion temperature | 867 ° F. |
