メチルセルロース 化学特性,用途語,生産方法
外観
白色〜わずかにうすい褐色, 粉末
定義
本品は、セルロース(*)のメチルエーテルである。参照表示名称：セルロース
溶解性
水に溶ける。水溶液は、高温で熱ゲル化し、冷却するとともに元に戻る。
解説
メチルセルロース，無臭の白色～帯黄白色の無晶または繊維状の粉末あるいは粒．冷水に可溶，熱水に不溶．水に溶解するには80～90 ℃ に加温し，よくかくはんして分散させ，同温度で20～30 min 放置し，5～10 ℃ に冷却する．水溶液を加温すると，はじめ粘度は下がるが，ふたたび増加してゲル化する．置換度の大きいほうがゲル化の温度が低い．薬用として緩下剤に用いられ，また水溶液としてのり剤，粘ちゅう剤，エマルション(乳濁液)およびラテックス安定剤，香粧品などに用いられる．
森北出版「化学辞典（第2版）
用途
糊(のり)剤、粘化剤、エマルジョンの安定剤、布のサイズ剤などに用いられる。人体に無毒であるので、乳化・保水などの目的で食品添加物として用いられるほか、化粧品、医薬にも配合されている。
化粧品の成分用途
結合剤、親水性増粘剤、乳化安定剤、香料
製法
メチルセルロースは、セルロースを水酸化ナトリウム水溶液および硫酸ジメチルと処理してメチル化するか、アルカリセルロースを加圧下で塩化メチルと処理する方法により合成される。セルロースがもつ全ヒドロキシ基のうち27～32％がメトキシ基になっているものは水溶性であり、38～43％のものは有機溶媒に可溶である。
主な用途／役割
ユリア樹脂系接着剤、メラミン樹脂系接着剤、エマルション系接着剤の増粘剤として使用される。
化学的特性
Methyl cellulose is a water soluble, gel-like substance with no odor and no taste.
使用
Methyl cellulose is used as a thickener and an emulsifier in various food and cosmetic products; as a gel in advanced cookery and as a lubricant. It is also involved in the treatment of constipation. It acts as a buffer additive in capillary electrophoresis to control electoosmotic flow for improved separations. In paper and textile industries, it is used as a sizing, thereby protecting the fibers from water or oil.
製造方法
Prepared from wood pulp or cotton by treatment with alkali and methylation of alkali cellulose with methyl chloride.
調製方法
Methylcellulose is prepared from wood pulp (cellulose) by
treatment with alkali followed by methylation of the alkali cellulose
with methyl chloride. The product is then purified and ground to
powder form.
一般的な説明
Odorless white or creamy white fibrous powder. Tasteless.
空気と水の反応
Methyl cellulose is hygroscopic. Swells in water to a viscous, colloidal solid. Slightly water soluble.
反応プロフィール
Methyl cellulose is incompatible with strong oxidizing agents. Methyl cellulose is also incompatible with aminacrine HCl, chlorocresol, mercuric chloride, phenol resorcinol, tannic acid and silver nitrate.
火災危険
Flash point data for Methyl cellulose are not available; however, Methyl cellulose is probably combustible.
安全性プロファイル
A poison by
intraperitoneal route. When heated to
decomposition it emits acrid smoke and
irritating fumes.
貯蔵
Methylcellulose powder is stable, although slightly hygroscopic.
The bulk material should be stored in an airtight container in a cool,
dry place.
Solutions of methylcellulose are stable to alkalis and dilute acids
at pH 3–11, at room temperature. At pH less than 3, acid-catalyzed
hydrolysis of the glucose–glucose linkages occurs and the viscosity
of methylcellulose solutions is reduced.On heating, solution
viscosity is reduced until gel formation occurs at approximately
50°C;
Methylcellulose solutions are liable to microbial spoilage and
antimicrobial preservatives should therefore be used. Solutions may
also be sterilized by autoclaving, although this process can decrease
the viscosity of a solution.The change in viscosity after
autoclaving is related to solution pH. Solutions at pH less than 4 had viscosities reduced by more than 20% subsequent to autoclaving.
不和合性
chlorocresol; mercuric chloride; phenol; resorcinol; tannic acid;
silver nitrate; cetylpyridinium chloride; p-hydroxybenzoic acid; paminobenzoic
acid; methylparaben; propylparaben; and butylparaben.
Salts of mineral acids (particularly polybasic acids), phenols, and
tannins will coagulate solutions of methylcellulose, although this
can be prevented by the addition of ethanol (95%) or glycol
diacetate. Complexation of methylcellulose occurs with highly
surface-active compounds such as tetracaine and dibutoline sulfate.
High concentrations of electrolytes increase the viscosity of
methylcellulose mucilages owing to the ‘salting out’ of methylcellulose.
With very high concentrations of electrolytes, the methylcellulose
may be completely precipitated in the form of a discrete or
continuous gel. Methylcellulose is incompatible with strong
oxidizing agents.
規制状況(Regulatory Status)
GRAS listed. Accepted as a food additive in the USA, Europe and
Japan. Included in the FDA Inactive Ingredients Database
(sublingual tablets; IM injections; intrasynovial injections; nasal
preparations; ophthalmic preparations; oral capsules, oral suspensions,
and oral tablets; topical and vaginal preparations). Included
in nonparenteral medicines licensed in the UK. Included in the
Canadian List of Acceptable Non-medicinal Ingredients.Reported
in the EPA TSCA inventory.
メチルセルロース 上流と下流の製品情報
原材料
準備製品