無水マレイン酸

解説無水マレイン酸，ムスイマレインサン，2,5-furandione．C4H2O3(98.06)．工業的には，ベンゼンを酸化バナジウムあるいは酸化モリブデンの存在下に空気酸化すると得られる．実験室的には，マレイン酸あるいはリンゴ酸を脱水するか，アセチルマレン酸無水物を熱分解すると得られる．無色の針状結晶．融点52.8 ℃，沸点202 ℃，95 ℃(2.66 kPa)．d1.48．昇華性．水，アセトン，酢酸エチル，クロロホルム，ベンゼンに可溶，四塩化炭素，石油エーテルに難溶．共役二重結合をもつ鎖状あるいは環状化合物と容易にディールス-アルダー反応を行う．還元すると無水コハク酸となる．また，加圧下でアンモニアあるいは種々のアミンと反応させると，アスパラギン酸あるいはそのN-置換体を生じる．不飽和ポリエステル樹脂および種々の共重合体の製造のほか，有機合成の中間体になる．皮膚や眼などについたときは十分に水で洗う．

用途可塑剤、合成樹脂塗料

用途不飽和ポリエステル樹脂、テトラハイドロフラン、フマール酸、コハク酸、リンゴ酸、紙サイズ剤、合成樹脂塗料、塩ビ安定剤、可塑剤、農薬、皮なめし、界面活性剤

説明Maleic Anhydride (MAN) is an organic compound with the chemical formula C4H203. It is the acid anhydride of maleic acid and in its pure state it is a colourless or white solid with an acrid odour. Maleic anhydride is truly a remarkable molecule in that it possesses two types of chemical functionality making it uniquely useful in chemical synthesis and applications.Maleic Anhydride is a multifunctional chemical intermediate with applications in several fields of chemical industry. Its major end use is as feedstock in the production of unsaturated polyester resins (UPR).These resins are used both in glass-reinforced and in unreinforced applications. The UPR end uses includes a wide range of applications in construction, marine and automobile industries.

使用Maleic Anhydride is heterocyclic compound used in the manufacture of unsaturated polyester resins. It has a wide range of other applications; it is used in synthetic tensides, insecticides, herbicides and fungicides.

一般的な説明Colorless crystalline needles, flakes, pellets, rods, briquettes, lumps or a fused mass. Melts at 113°F. Shipped both as a solid and in the molten state. Vapors, fumes and dusts strong irritate the eyes, skin and mucous membranes. Flash point 218°F. Autoignition temperature 890°F. Used to make paints and plastics and other chemicals.

製造方法To a flask equipped with a Dean-Stark trap, condenser, and mechanical stirrer is added 116 gm (1.0 mole) of maleic acid and 120 ml of tetrachloroethane. The contents are heated, the water (18 ml, 1.0 mole) distilled off as the azeotrope, and the residue distilled under reduced pressure to afford 87.7 gm (89.5%) of the anhydride, b.p. 82-84°C (15 mm), m.p. 53°C. The residue remaining in the flask consists of about 10 gm of fumaric acid, m.p. 287°C. Fumaric and maleic acids both give maleic anhydride on heating. Fumaric acid must first be heated to a higher temperature to effect its conversion to maleic acid prior to its dehydration.

Maleic anhydride was traditionally manufactured by the oxidation of benzene or other aromatic compounds. As of 2006, only a few smaller plants continue to use benzene; due to rising benzene prices, most maleic anhydride plants now use n-butane as a feedstock. In both cases, benzene and butane are fed into a stream of hot air, and the mixture is passed through a catalyst bed at high temperature. The ratio of air to hydrocarbon is controlled to prevent the mixture from catching on fire. Vanadium pentoxide and molybdenum trioxide are the catalysts used for the benzene route, whereas vanadium and phosphorus oxides are used for the butane route. 2 CH3CH2CH2CH3 + 7 O2 → 2 C2H2(CO)2O + 8 H2O.

合成方法ベンゼン酸化法，ブタン酸化法

純化方法Crystallise it from *benzene, CHCl3, CH2Cl2 or CCl4. Sublime it under reduced pressure. [Skell et al. J Am Chem Soc 108 6300 1986, Beilstein 17 III/IV 5897, 17/11 V 55.]