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外観
無色澄明の液体
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性質
芳香性のある無色の液体で、比重は0.9044で水よりも軽く、水に溶解しないため、水に浮きます。引火点32℃、融点-30.63℃、沸点145.2℃、屈折率は1.5439です。アルコールやエーテルに可溶です。
スチレンは、の水素原子の1つがビニル基に置換された構造をしています。ビニル基を持つため、極めて反応性が高く、加熱・光・過酸化物等により容易に重合してを生成し、液体状態から徐々に粘度が高くなり、無色の固体状に変化します。
蒸気密度は3.6で空気より重く、低所に滞留し爆発性混合ガスを作りやすいです。日光などの影響で温度が上がると重合することがあり、火災または爆発の危険性を伴います。そのため、通風の良い冷暗所に保管することが推奨されます。
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溶解性
水に難溶 (0.03g/100ml, 25℃), エタノール, エーテルに混和。エタノール及びアセトンに極めて溶けやすく、水にほとんど溶けない。
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解説
スチレン,C8H8(104.15)．スチロール，フェニルエテンともいう．不飽和炭化水素の側鎖をもつ芳香族の一つ．石炭および石油系炭化水素の熱分解生成物中に少量存在する．工業的製法は，おもにエチルベンゼンを原料とする方法である．現在，操業されている製造法には，高温(590 ℃ 以上)，スチーム存在下で鉄-クロム-カリウム系触媒を用いたエチルベンゼンの直接脱水素法と，エチルベンゼンを一度酸化して過酸化物をつくり，炭化水素(プロペンなど)で還元してアルコールとし，さらにこれを脱水する方法とがある．後者の場合には還元の際に有用な酸化物(酸化プロピレンなど)を併産することができる．ほかにエテン製造の際に副生する炭化水素油から分離する方法もある．引火性，特臭を有する無色の液体．融点－30.63 ℃，沸点145.14 ℃．0.90122．1.54395．爆発範囲1.1～6.1体積％．各種有機溶剤に可溶，水に不溶．反応性がきわめて高いため，貯蔵には重合防止剤の添加を必要とする．重要な石油化学工業の中間体で，数多くの誘導製品がある．おもなものは，スチレン-ブタジエンゴム(SBR)，ポリスチレン，ABS樹脂などである．
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用途
ポリエチレンの製造原料
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用途
ポリスチレン樹脂?アクリロニトリルブタジエンスチレン共重合体 (ABS) 樹脂?合成ゴム?不飽和ポリエステル樹脂合成原料, 塗料樹脂?イオン交換樹脂?化粧品原料
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用途
大気中等スチレンのGC分析用標準液。
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用途
スチレンモノマー定量用標準品。
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説明
Styrene has a characteristic, sweet, balsamic, almost floral odor that is extremely penetrating. Styrene occurs naturally in plants. It was first isolated from a resin called storax obtained from the inner bark of the Oriental sweet gum tree (Liquidambar orientalis) by Bonastre. In 1839, the German apothecary Eduard Simon prepared styrene by distilling it from storax and called it styrol. Simon observed it solidifi ed into a rubbery substance after being stored and believed it had oxidized into styrol oxide. Subsequent analysis showed the solid did not contain oxygen and it was renamed metastyrol. This was the first written record of polymerization in chemistry. In 1845, the English chemist, John Blyth, and the German chemist, August Wilhelm von Hofmann (1818 1892), observed that styrene was converted to polystyrene by sunlight and that styrene could be polymerized to polystyrene by heating in the absence of oxygen. It took another 70 years for the polymerization of styrene to be described by Hermann Staudinger (1881 1965) in the 1920s. This laid the foundation for the commercial polystyrene industry that developed in the 1930s.
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化学的特性
Styrene is a colorless or yellow, sweet odor liquid with a penetrating odor. It is produced during alkylation of benzene with ethylene. It is highly reactive and polymerizes rapidly with a violent explosive reaction. This demands proper handling, transportation, and storage by adding polymerization inhibitors in adequate quantities during these operations. Styrene monomer has been extensively used in the manufacture of chemical intermediates, fi lling components, plastics, resins, and stabilizing agents.
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物理的性質
Clear, colorless, watery liquid with a penetrating or pungent rubber-like odor. Becomes yellow to
yellowish-brown on exposure to air. Experimentally determined odor threshold concentrations in
air for inhibited and unhibited styrene were 0.1 and 0.047 ppmv, respectively (Leonardos et al.,
1969). Experimentally determined detection and recognition odor threshold concentrations were
220–640 μg/m3 (52–150 ppbv) and 64 μg/m3 (15 ppbv), respectively (Hellman and Small, 1974).
At 40 °C, the average odor threshold concentration and the lowest concentration at which an odor
was detected were 65 and 37 μg/L, respectively. At 25 °C, the lowest concentration at which a
taste was detected was 94 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 3.6 and 120 μg/L,
respectively (Alexander et al., 1982).
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天然物の起源
Reported found in cranberry and bilberry, currants, grape, parsley, milk and dairy products, whiskey, cocoa, coffee, tea, roasted filberts and roasted peanuts. Also reported found in fresh apple, guava fruit, pineapple, vinegar, butter, fish oil, black tea, roasted filbert, roasted peanut, soybean, plum brandy, apple brandy, Brazil nut, rice bran, Bourbon vanilla, grapes, peach, strawberry, onion, peas, bell pepper, cassia leaf, cheeses, parsley, milk, boiled and scrambled egg, lean fish, fish oil, cooked chicken and beef, rum, malt and Scotch whiskey, cider, grape, wine, cocoa, coffee, honey, cloudberry, plum, rose apple, beans, trassi, walnut, buckwheat, soursop, watercress, kiwifruit, wild rice, sapodilla fruit, nectarine, okra, crab, crayfish and pawpaw.
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使用
Styrene (monomer) is a viscous, highly flammable liquid that evaporates easily and polymerizes readily to polystyrene unless a stabilizer is added. Styrene is used in multiple industries, especially in reinforced plastics (e.g., fiberglass boats), and is widely used to make plastics and rubber, packaging materials (e.g., packing peanuts ), insulation for buildings, plastic pipes, food containers (e.g., takeout containers), and carpet backing) (ATSDR, 2010).
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定義
ChEBI: A vinylarene that is benzene carrying a vinyl group. It has been isolated from the benzoin resin produced by Styrax species.
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調製方法
Styrene is made by dehydrogenation of ethylbenzene at high temperature using metal catalysts: C6H5CH2CH2(g)→ C6H5CH = CH2(g) + H2(g). This is called the EB/SM (ethylbenzene/styrene monomer) process. Styrene can also be made by PO/SM (propylene oxide/styrene monomer) process). This process starts by oxidizing ethylbenzene (C6H5CH2CH2) to its hydroperoxide (C6H5CH(OOH)CH3), which is then used to oxidize propylene (CH3CH = CH2) to produce propylene oxide (CH3CH2CHO) and phenylethanol (C6H5CH(OH)CH3). The phenylethanol is then dehydrated to give styrene and water. Styrene can also be synthesized by reacting benzene and ethylene or natural gas.
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製造方法
Prepared from ethylbenzene or from phenylethanol.
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安全性
スチレンは引火性液体であり、自己反応性化学物質であることが報告されています。また、加温や光、酸化剤、酸素および過酸化物の影響下で重合し、火災や爆発の危険を生じることがあるため注意が必要です。
吸入すると有害で、皮膚および眼に刺激を与えることがあります。長期または反復曝露により中枢神経系および肝臓障害を引き起こす可能性があるため、作業環境における許容濃度にも注意が必要です。
環境省の環境リスク初期評価書では、呼吸によってスチレンを取り込んだ場合、健康への影響があることが示唆されています。取扱う際には、保護手袋、不浸透性保護前掛け、保護眼鏡か安全ゴーグル、有機ガス用防毒マスクなどの適切な保護具を用いることを推奨します。
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製造法
無色、特異なにおいをもつ液体。工業的製造法としては、塩化アルミニウム触媒の存在下、ベンゼンとエチレンからエチルベンゼンをつくり、ついで酸化鉄(Ⅲ)‐三酸化クロム系の金属酸化物触媒の存在下、高温で脱水素する。スチレンは反応性に富み、明るいところに放置すると重合し、空気の存在下では過酸化物を与えるので、カテコールなどの重合禁止剤や酸化防止剤を加えて貯蔵する。有機過酸によりスチレンエポキシドを与え、過マンガン酸カリウムで酸化すると安息香酸を生ずる。スチレンは高分子工業の重要な原料である。スチレンを原料とする樹脂としては、ポリスチレン、AS樹脂、ABS樹脂、スチレン・メチルメタアクリラート樹脂、ハイスチレンがあり、塗料、乾性油、イオン交換樹脂として用いられる。
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一般的な説明
A clear colorless to dark liquid with an aromatic odor. Flash point 90°F. Density 7.6 lb/gal. Vapors heavier than air and irritating to the eyes and mucous membranes. Subject to polymerization. If the polymerization takes place inside a closed container, the container may rupture violently. Less dense than water and insoluble in water. Used to make plastics, paints, and synthetic rubber.
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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
STYRENE MONOMER is a colorless, oily liquid, moderately toxic, flammable. A storage hazard above 32°C, involved in several industrial explosions caused by violent, exothermic polymerization [Bond, J., Loss Prev. Bull., 1985, (065), p. 25]. Polymerization becomes self-sustaining above 95°C [MCA SD-37, 1971]. Presence of an inhibitor lessens but does not eliminate the possibility of unwanted polymerization. Violent polymerization leading to explosion may be initiated by peroxides (e.g., di-tert-butyl peroxide, dibenzoyl peroxide), butyllithium, azoisobutyronitrile. Reacts violently with strong acids (sulfuric acid, oleum, chlorosulfonic acid), strong oxidizing agents [Lewis, 3rd ed., 1993, p. 1185]. Reacts with oxygen above 40°C to form explosive peroxide [Barnes, C. E. et al., J. Amer. Chem. Soc., 1950, 72, p. 210]. Oxidizes readily in air to form unstable peroxides that may explode spontaneously [Bretherick 1979 p.151-154, 164]. Mixing styrene in equal molar portions with any of the following substances in a closed container caused the temperature and pressure to increase: chlorosulfonic acid, oleum, and sulfuric acid [NFPA 1991].
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危険性
Flammable, moderate fire risk, explosive
limits in air 1.1–6.1%, must be inhibited during
storage. Toxic by ingestion and inhalation. Central
nervous system impairment, upper respiratory
tract irritant, and peripheral neuropathy. Possible
carcinogen.
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健康ハザード
Like all other aromatic hydrocarbons, styreneis an irritant to skin, eyes, and mucous membranes and is narcotic at high concentrations.Exposure to its vapors may cause drowsiness,nausea, headache, fatigues, and dizziness inhumans (Hamilton and Hardy 1974). Inhalation of 10,000 ppm for 30–60 minutes maybe fatal to humans.
Absorption of styrene by inhalation isthe major path of absorption into the body.Skin absorption of the liquid is also significant. According to an estimate, contactwith styrene-saturated water for an hour orbrief contact with the liquid may result inabsorption equivalent to 8 hours of inhalationof 12 ppm (Dutkiewicz and Tyras 1968). Itmay accumulate in the body due to its highsolubility in fat. This would happen whenthe metabolic pathway becomes saturated atexposure concentrations of 200 ppm (ACGIH 1986). Mandelic acid and benzoylformic acidare the major urinary metabolites. However,the excretion of mandelic acid was less whenstyrene was absorbed through the skin.
Styrene tested positive in an EPA mutagenicity study. It tested positive in a histidine reversion–Ames test, Saccharomycescerevisiae gene conversion, in vitro humanlymphocyte micronucleus, and Drosophilamelanogaster sex-linked lethal tests (NIOSH1986). Carcinogenicity of styrene in humansis not known. There is limited evidence of carcinogenicity in animals for both the monomerand the polymer..
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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. At elevated temperatures such as in fire conditions, polymerization may take place which may lead to container explosion.
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使用用途
スチレンは、主に合成樹脂の原料として利用されます。ポリスチレン (PS) を始めとして、ABS樹脂やAS樹脂、不飽和ポリエステルなどの合成樹脂の製造に使用されます。また、スチレンは熱・触媒の存在で容易に重合してポリスチレンとなるため、重合用のモノマーとしても利用可能です。
そのほか、合成ゴムであるスチレンブタジエンゴムやポリスチレン、合成樹脂塗料、FRP等の製造原料としてだけでなく、粘着剤や接着剤、等の建材、乾性油、、等の製造にも利用されています。
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化学性质
重合性モノマーで，アルキド樹脂の変性剤として用いられる。
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安全性プロファイル
Confirmed carcinogen. Experimental poison by ingestion, inhalation, and intravenous routes. Moderately toxic experimentally by intraperitoneal route. Mildly toxic to humans by inhalation. An experimental teratogen. Human systemic effects by inhalation: eye and olfactory changes. It can cause irritation and violent itching of the eyes @200 ppm, lachrymation, and severe human eye injuries. Its toxic effects are usually transient and result in irritation and possible narcosis. Experimental reproductive effects. Human mutation data reported. A human skin irritant. An experimental skin and eye irritant. The monomer has been involved in several industrial explosions. It is a storage hazard above 32°C. A very dangerous fire hazard when exposed to flame, heat, or oxidants. Explosive in the form of vapor when exposed to heat or flame. Reacts with oxygen above 40°C to form a heat-sensitive explosive peroxide. Violent or explosive polymerization may be initiated by alkahmetal-graphite composites, butyllithium, dibenzoyl peroxide, other initiators (e.g., azoisobutyronitrile, di-tert-butyl peroxide). Reacts violently with chlorosulfonic acid, oleum, sulfuric acid, chlorine + iron(IⅡ) chloride (above 50°C). May ignite when heated with air + polymerizing polystyrene. Can react vigorously with oxidizing materials. To fight fire, use foam, CO2, dry chemical. When heated to decomposition it emits acrid smoke and irritating fumes
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職業ばく露
Styrene is used in the production of plastics and polystyrene resins. It is also used in combination with 1,3-butadiene or acrylonitrile to form copolymer elastomers, butadiene-styrene rubber; and acrylonitrilebutadiene-styrene. It is also used in the manufacture of protective coatings; resins, polyesters; in making insulators and in drug manufacture.
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発がん性
Styrene is reasonably anticipated to be a human carcinogen based on limited evidence of carcinogenicity from studies in humans, sufficient evidence of carcinogenicity from studies in experimental animals, and supporting data on mechanisms of carcinogenesis.
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製造方法
脱水素法
原料のエチルベンゼンを高温で脱水素してスチレンを合成する方法です。を主体とした触媒を用いて、550℃以上の減圧下で行います。この反応は可逆反応であるため、エチルベンゼンの酸化により生成する水素を除去することで反応を進行させてスチレンを合成します。
他にも反応で生成する水素を酸化させることで、水素の分圧を下げ、かつ反応熱により系内温度を上昇させることで、反応を進行させてスチレンを合成する方法も行われています。
ハルコン法
アメリカのHalcon International社が開発した合成法であり、エチルベンゼンとプロピレンからスチレンと酸化プロピレンを合成できます。この方法では、エチルベンゼンを空気酸化してエチルベンゼンヒドロペルオキシドとし、2～7 MPa、100～130℃の反応条件下でプロピレンと反応させると、酸化プロピレンとメチルベンジルアルコールを生成します。
さらに、生成したメチルベンジルアルコールを酸化チタン触媒により接触的に脱水することでスチレンが得られます。酸化プロピレンとスチレンの収率が高く、これらの同時合成法として有利な製造方法とされています
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貯蔵
Styrene is stored in a flammable liquid storagecabinet, separated from oxidizing substances An inhibitor such as 4-tert-butylcatechol intrace amounts is added to the monomer toprevent polymerization. It is shipped in glassbottles, metal cans, drums, and tank cars.
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合成方法
ベンゼンのアルキル化と脱水素を経て合成
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輸送方法
UN2055 Styrene monomer, stabilized, Hazard Class: 3; Labels: 3-Flammable liquid.
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純化方法
Styrene is difficult to purify and keep pure. 25 1.5441. Usually it contains added inhibitors (such as a trace of hydroquinone). Wash it with aqueous NaOH to remove inhibitors (e.g. tert-butanol), then with water, dry it for several hours with MgSO4 and distil it at 25o under reduced pressure in the presence of an inhibitor (such as 0.005% p-tert-butylcatechol). It can be stored at -78o. It can also be stored and kept anhydrous with Linde type 5A molecular sieves, CaH2, CaSO4, BaO or sodium, being fractionally distilled, and distilled in a vacuum line just before use. Alternatively styrene (and its deuterated derivative) are passed through a neutral alumina column before use [Woon et al. J Am Chem Soc 108 7990 1986, Collman J Am Chem Soc 108 2588 1986]. [Beilstein 5 IV 1334.]
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不和合性
Styrene May form explosive mixture with air. A storage hazard above 31C. Upon heating to 200C, styrene polymerizes to form polystyrene, a plastic. Before entering confined space where this chemical may be present, check to make sure that an explosive concentration does not exist. Store in a cool, dry area away from oxidizers, catalysts for vinyl polymers; peroxides, strong acids; aluminum chloride. May polymerize if contaminated, subjected to heat; under the influence of light; and on contact with many compounds, such as oxygen, oxidizing agents; peroxides and strong acids. Usually contains an inhibitor, such as tert-butylcatechol. Corrodes copper and copper alloys. Attacks some plastics, rubber, and coatings.
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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. In some cases, recovery and recycle of styrene monomer is economic and the technology is available.
