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外観
無色澄明の液体
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溶解性
水に微溶 (0.02g/100ml水, 25℃), エタノール, エーテルに混和。エタノール、エーテル、アセトン、二硫化炭素に可溶。水にほとんど不溶。エタノール及びジエチルエーテルに溶けやすく、水にほとんど溶けない。
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用途
イソフタル酸?メタキシレンジアミン原料，キシレン樹脂原料。
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化学的特性
Xylene exists in three isomeric forms, ortho-,
meta-, and para-xylene. Commercial xylene is a mixture of
these three isomers and may also contain ethylbenzene as
well as small amounts of toluene, trimethylbenzene, phenol,
thiophene, pyridine, and other nonaromatic hydrocarbons.
m-Xylene is predominant in commercial xylene.
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物理的性質
Clear, colorless, watery liquid with a sweet, aromatic odor. An odor threshold concentration of 48
ppbv was reported by Nagata and Takeuchi (1990).
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使用
m-Xylene is used in the production of isophthalic acid, which is a monomer and utilized in preparation of polyethylene terephthalate. It is used as an important starting material in the production of 2,4- and 2,6-xylidine. It is used as solvent in histology.
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定義
ChEBI: A xylene carrying methyl groups at positions 1 and 3.
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一般的な説明
A colorless watery liquid with a sweet odor. Less dense than water. Insoluble in water. Irritating vapor.
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空気と水の反応
Highly flammable. Insoluble in water.
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反応プロフィール
m-Xylene may react with oxidizing materials. .
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健康ハザード
Vapors cause headache and dizziness. Liquid irritates eyes and skin. If taken into lungs, causes severe coughing, distress, and rapidly developing pulmonary edema. If ingested, causes nausea, vomiting, cramps, headache, and coma; can be fatal. Kidney and liver damage can occur.
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火災危険
Behavior in Fire: Vapor is heavier than air and may travel considerable distance to a source of ignition and flash back.
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化学反応性
Reactivity with Water No reaction; Reactivity with Common Materials: No reaction; Stability During Transport: Stable; Neutralizing Agents for Acids and Caustics: Not pertinent; Polymerization: Not pertinent; Inhibitor of Polymerization: Not pertinent.
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安全性プロファイル
Moderately toxic by
intraperitoneal route. Wdly toxic by
ingestion, skin contact, and inhalation. An
experimental teratogen. Human systemic
effects by inhalation: motor activity changes,
ataxia, and irritabihty. Experimental
reproductive effects. A severe skin irritant.
A common air contaminant. A very
dangerous fire hazard when exposed to heat
or flame; can react with oxidzing materials.
Explosive in the form of vapor when
exposed to heat or flame. To fight fire, use
foam, CO2, dry chemical. Emitted from
modern building materials (CENEAR
69,22,91). When heated to decomposition it
emits acrid smoke and irritating fumes. See
also other xylene entries.
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職業ばく露
Xylene is used as a solvent; as a constituent
of paint, lacquers, varnishes, inks, dyes, adhesives,
cements, cleaning fluids, and aviation fuels; and as a chemical
feed-stock for xylidines, benzoic acid; phthalic anhydride;
isophthalic, and terephthalic acids; as well as their
esters (which are specifically used in the manufacture
of plastic materials and synthetic textile fabrics). Xylene
is also used in the manufacture of quartz crystal oscillators,
hydrogen peroxide; perfumes, insect repellants; epoxy
resins; pharmaceuticals; and in the leather industry.
m-Xylene is used as an intermediate in preparation of isophthalic
acid; o-xylene is used in manufacture of phthalic
anhydride and in pharmaceutical and insecticide synthesis.
p-xylene is used in pharmaceutical and insecticide synthesis
and in production of polyester.
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輸送方法
UN1307 Xylenes, Hazard Class: 3; Labels:
3-Flammable liquid.
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純化方法
The general purification methods listed under xylene are applicable. The o-and p-isomers can be removed by their selective oxidation when a m-xylene sample containing them is boiled with dilute HNO3 (one part conc acid to three parts water). After washing with water and alkali, the product can be steam distilled, collected as for o-xylene, then distilled and purified further by sulfonation. [Clarke & Taylor J Am Chem Soc 45 831 1923.] m-Xylene is selectively sulfonated when a mixture of xylenes is refluxed with the theoretical amount of 50-70% H2SO4 at 85-95o under reduced pressure. By using a still resembling a Dean and Stark apparatus, water in the condensate can be progressively withdrawn while the xylene is returned to the reaction vessel. After cooling, then adding water, unreacted xylenes are distilled off under reduced pressure. The m-xylene sulfonic acid is subsequently hydrolysed by steam distillation up to 140o, the free m-xylene is washed, dried with silica gel and again distilled. It is stored over molecular sieves Linde type 4A. [Beilstein 5 H 370, 5 I 182, 5 II 287, 5 III 823, 5 IV 932.]
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不和合性
Vapor may form explosive mixture
with air. Incompatible with oxidizers (chlorates, nitrates,
peroxides, permanganates, perchlorates, chlorine, bromine,
fluorine, etc.); contact may cause fires or explosions. Keep
away from alkaline materials, strong bases, strong acids,
oxoacids, and epoxides. Electrostatic charges can be
generated from agitation or flow.
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廃棄物の処理
Consult with environmental
regulatory agencies for guidance on acceptable disposal
practices. Generators of waste containing this contaminant
(≥100 kg/mo) must conform with EPA regulations governing
storage, transportation, treatment, and waste disposal.
Incineration.
