エチルベンゼン 化学特性,用途語,生産方法
外観
無色澄明の液体
製造法
石油のC8留分の成分だが、各成分は沸点が接近しているので分離はむずかしい。工業的には塩化アルミニウム、三フッ化ホウ素、リン酸などの触媒の存在下、ベンゼンにエチレンを吹き込んで製造する。酸化鉄‐三酸化クロム‐炭酸カリウム系脱水素触媒の存在下で600℃前後の高温に加熱すると、エチル基CH3-CH2-がビニル基CH2=CH-に変化してスチレンになる。この方法により、合成樹脂や合成ゴムの原料として重要なスチレンが工業的に製造される。エチルベンゼンは酸化すると安息香酸を与え、光塩素化でα(アルファ)-位が塩素化される。
溶解性
水に難溶 (0.015g/100ml水, 20℃) , エタノール, エーテルに可溶。
解説
C8H10(106.17)．C6H5C2H5．石油精製の際のキシレン留分中に含まれるが，ベンゼンにエテンをフリーデル-クラフツ付加させて製造される．無色の液体．融点－94.4 ℃，沸点136 ℃．d2040.8671．n20D1.4960．引火点20 ℃．多くの有機溶剤とまざる．脱水素してスチレンを製造する．[CAS 100-41-4]
森北出版「化学辞典（第2版）
用途
スチレンモノマー合成原料,有機合成原料,塗料?インキ?接着剤溶剤、NITE初期リスク評価書;スチレン原料,有機合成原料、SRI:CHEMICAL ECONOMICS HANDBOOK;スチレンモノマー原料,有機合成原料,溶剤,ラッカーの希釈剤、化学工業日報社
用途
エチルベンゼンは，水に不溶，ほとんどの有機溶媒と均一に混ざる(溶ける)。ベンゼン，トルエン，キシレンとともに主要な芳香族石油化学製品の一つであり，広範で重要な主要化学原料である。工業的には，主として，ベンゼンを酸触媒(液相法では塩化アルミニウムなど，気相法ではリン酸‐担体)を用いエチレンでアルキル化して製造される。
用途
スチレンの合成、有機合成原料、溶剤
化学的特性
Ethylbenzene is a colorless liquid. Pungent
aromatic odor. The Odor Threshold is 0.0920.60 ppm
物理的性質
Clear, colorless liquid with a sweet, gasoline-like odor. At 40 °C, the average odor threshold
concentration and the lowest concentration at which an odor was detected were 550 and 150 μg/L,
respectively. Similarly, at 25 °C, the average taste threshold concentration and the lowest
concentration at which a taste was detected were 780 and 390 μg/L, respectively (Young et al.,
1996). The average least detectable odor threshold concentrations in water at 60 °C and in air at 40
°C were 2.4 and 72 μg/L, respectively (Alexander et al., 1982). Cometto-Mu?iz and Cain (1994)
reported an average nasal pungency threshold concentration of 10,100 ppm
v.
天然物の起源
Has apparently not been reported to occur in nature.
使用
Anesthetic.
Ethylbenzene is almost exclusively (> 99%) used as an intermediate for the production of styrene monomer. Less than 1 % of the ethylbenzene produced is used as a paint solvent or as an intermediate for the production of diethylbenzene and acetophenone (IARC 2000).
Ethylbenzene is a constituent (15-20%) of commercial xylene (“mixed xylenes”), and hence used as a component of solvents, as a diluent in paints and lacquers, and as a solvent in the rubber and chemical manufacturing industries (WHO 1996).
Ethylbenzene has been added to motor and aviation fuels because of its anti-knock properties. Estimates of ethylbenzene in gasoline have ranged from <1-2.7%. (IARC 2000).
製造方法
By Friedel-Crafts reaction on benzene, ethylbromide and aluminium chloride (Arc tander, 1969).
Ethylbenzene is manufactured by alkylation from benzene and ethylene.
定義
ethylbenzene: A colourless flammableliquid, C
6H
5C
2H
5; r.d. 0.867;m.p. –95°C; b.p. 136°C. It is madefrom ethene and ethybenzene by aFriedel–Crafts reaction and is usedin making phenylethene (for polystyrene).
調製方法
Ethylbenzene is produced by alkylation of benzene with ethylene, except for a very small fraction that is recovered from mixed C8 aromatics by superfractionation. The reaction takes place on acidic catalysts and can be carried out either in the liquid or vapor phase.
一般的な説明
A clear colorless liquid with an aromatic odor. Flash point 59°F. Less dense than water (at 7.2 lb / gal) and insoluble in water. Hence floats on water. Vapors heavier than air. Used as a solvent and to make other chemicals.
空気と水の反応
Highly flammable. Insoluble in water.
反応プロフィール
Ethylenzene can react vigorously with strong oxidizing materials .
危険性
Toxic by ingestion, inhalation, and skin
absorption; irritant to skin and eyes. Flammable,
dangerous fire risk. Possible carcinogen.
健康ハザード
The acute toxicity of Ethylbenzene is low.At high concentrations its exposure producesnarcotic effects similar to benzene andtoluene. A 4-hour exposure to a concentrationof 4000 ppm proved fatal to rats. The lethaldose varies with species. Deaths resulted fromintense congestion and edema of the lungs.
Other than the narcotic effects, Ethylbenzeneexhibits irritant properties that are somewhatgreater than those of benzene or toluene.It is an irritant to the skin, eyes, and nose.Repeated contact with the liquid may causereddening of the skin and blistering. Thevapors at 200 ppm may cause mild irritationof the eyes in humans, which may becomesevere and lacrimating at 2000–3000 ppm.
The oral toxicity in animals was foundto be low to very low. An LD50 value of3500 mg/kg for rats has been documented(NIOSH 1986). No adverse effects werenoted in animals subjected to chronic inhalationexposure at below 400 ppm. At higherdosages only the liver was affected (ACGIH1986). Ethylbenzene is eliminated from thebody by metabolic excretion. The urinarymetabolites in humans are mainly mandelicacid, C6H5CH(OH)COOH, and benzoylformicacid, C6H5COCOOH.
使用用途
エチルベンゼンは低級アルキルベンゼンの一種です。一般的にはエチレンとベンゼンを原料とした触媒反応によって作られていますが、キシレンから分離することで製造することもあります。
エチルベンゼンは主にスチレンモノマーの原料として使われています。その他に、塗料や、インキなどの溶剤としても用いられています。また、上記の通りキシレンにもエチルベンゼンは一定量含まれており、灯油やガソリンにも1%程度含まれています。
有害性と法規制
エチルベンゼンはやベンゼンなどの低分子芳香族化合物と同様に引火性の高い液体で、消防法の危険物第四類 第二石油類に該当します。毒物及び劇物取締法には該当していませんが、人体への有害性があることから、労安法の特定化学物質の第二類に該当するほか、表示・通知対象物質にも該当しています。したがってエチルベンゼンを使用する事業場はリスクアセスメントを行う必要があります。
その他、エチルベンゼンはPRTR法の第一種指定化学物質であるなど、種々の法律が適用される物質です。使用前には最新のSDSを確認の上、適切な取り扱いを行うことが求められます。
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.
安全性プロファイル
Moderately toxic by
ingestion and intraperitoneal routes. Mildly
toxic by inhalation and skin contact. An
experimental teratogen. Other experimental
reproductive effects. Human systemic
effects by inhalation: eye, sleep, and
pulmonary changes. An eye and skin irritant.
Human mutation data reported. The liquid
is an irritant to the skin and mucous
membranes. A concentration of 0.1% of the
vapor in air is an irritant to human eyes, and
a concentration of 0.2% is extremely
irritating at first, then causes dizziness,
irritation of the nose and throat, and a sense
of constriction in the chest. Exposure of
guinea pigs to 1% concentration has been
reported as causing ataxia, loss of
consciousness, tremor of the extremities,
and finally death through respiratory failure.
The pathological findings were congestion
of the brain and lungs with edema. A very dangerous fire and explosion hazard when exposed to heat or flame; can
react vigorously with oxidizing materials. To
fight fire, use foam, CO2, dry chemical.
Emitted from modern budding materials
(CENEAR 69,22,91). When heated to
decomposition it emits acrid smoke and
irritating fumes.
職業ばく露
Ethylbenzene is used in styrene manufacture and in synthesis of p-nitroacetophenone; in the
manufacture of cellulose acetate, and synthetic rubber. It is
also used as a solvent or diluent; and as a component of
automotive and aviation gasoline. Significant quantities of
EB are present in mixed xylenes. These are used as dilatants in the paint industry, in agricultural sprays for insecticides and in gasoline blends (which may contain as much
as 20% EB). In light of the large quantities of EB produced
and the diversity of products in which it is found, there
may exist environmental sources for ethylbenzene, e.g.,
vaporization during solvent use; pyrolysis of gasoline and
emitted vapors at filling stations. Groups of individuals
who are exposed to EB to the greatest extent and could represent potential pools for the expression of EB toxicity
include: (1) individuals in commercial situations where
petroleum products or by-products are manufactured e.g.,
rubber or plastics industry); (2) individuals residing in areas
with high atmospheric smog generated by motor vehicle
emissions
代謝
The main oxidation of ethyl benzene occurs at the activated α-methylene group to yield methylphenylcarbinol which is also the precursor of hippuric and mandelic acids. Both optical isomers of methylphenylcarbinol are formed, probably in equal amounts, and these have been isolated from the urine of rabbits as the corresponding glucuronides. The two optical forms of mandelic acid have also been found (Williams, 1959).
輸送方法
UN1175 Ethylbenzene, Hazard Class: 3; Labels:
3-Flammable liquid
不和合性
Vapors 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. Attacks plastics and rubber. May
accumulate static electrical charges, and may cause ignition
of its vapors.
廃棄物の処理
Dissolve or mix the material
with a combustible solvent and burn in a chemical incinerator
equipped with an afterburner and scrubber. All federal, state,
and local environmental regulations must be observed
エチルベンゼン 上流と下流の製品情報
原材料
準備製品