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外観
白色の粉末
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定義
本品は、カルシウムの水酸化物であり、次の化学式で表される。
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反応性
消石灰ともいう。酸化カルシウム（生石灰）に水または水蒸気を作用させると得られる（生石灰の消和）。急速に生成したものは白色粉末であるが、水中に放置すると六方晶系の板状晶に変わる。加熱すると580℃で水蒸気を出して分解し、酸化カルシウムに戻る。
Ca(OH)2→CaO＋H2O
水にわずかしか溶けず、しかも温度が上昇すると溶解度はかえって減少する。水酸化カルシウム，水溶液は石灰水とよばれ、強いアルカリ性を示す。工業的には懸濁液の形で使われることが多く、これは石灰乳とよばれる。固体または溶液の状態で二酸化炭素を吸収し、水に不溶性の炭酸カルシウムに変わる。Ca(OH)2＋CO2→CaCO3＋H2O
また、塩素を吸収して次亜塩素酸カルシウム（高度さらし粉の主成分）を生成する。水酸化カルシウムは安価な強アルカリ物質なので、酸性廃棄物の処理剤、酸性土壌の中和剤、消毒剤などとして用いられる。化学工業ではさらし粉の原料となるほか、反応用アルカリとして広く利用され、建築分野でもモルタル、漆食(しっくい)の材料として重要である。［鳥居泰男］
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溶解性
水に難溶, 酸に可溶。酸には発熱して溶ける。グリセリン、糖および塩化アンモニウム水溶液に可溶。エタノールに不溶。水100gに対する溶解度は0.185g(0℃)、0.077g(100℃)。水に溶けにくく、エタノール及びジエチルエーテルにほとんど溶けない。塩酸又は硝酸に溶ける。
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解説
カルシウムの水酸化物。消石灰ともいう。酸化カルシウム（生石灰）に水または水蒸気を作用させると得られる（生石灰の消和）。急速に生成したものは白色粉末であるが、水中に放置すると六方晶系の板状晶に変わる。加熱すると580℃で水蒸気を出して分解し、酸化カルシウムに戻る。 Ca(OH)2→CaO＋H2O 水にわずかしか溶けず、しかも温度が上昇すると溶解度はかえって減少する。水溶液は石灰水とよばれ、強いアルカリ性を示す。工業的には懸濁液の形で使われることが多く、これは石灰乳とよばれる。固体または溶液の状態で二酸化炭素を吸収し、水に不溶性の炭酸カルシウムに変わる。 Ca(OH)2＋CO2→CaCO3＋H2O また、塩素を吸収して次亜塩素酸カルシウム（高度さらし粉の主成分）を生成する。 水酸化カルシウムは安価な強アルカリ物質なので、酸性廃棄物の処理剤、酸性土壌の中和剤、消毒剤などとして用いられる。化学工業ではさらし粉の原料となるほか、反応用アルカリとして広く利用され、建築分野でもモルタル、漆食(しっくい)の材料として重要である。［鳥居泰男］[補完資料] | 水酸化カルシウム（データノート）
小学館 日本大百科全書(ニッポニカ) ）
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用途
高純度金属化合物。
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用途
汎用試薬。
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用途
さらし粉、農薬、肥料等の原料。
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用途
建築用、肥料、サラシ粉、豆炭、練炭、非鉄金属、パルプ、製紙、食品添加物、農薬化粧品原料(清浄用化粧品、頭髪化粧品、基礎化粧品、メークアップ化粧品、芳香化粧品、日焼け?日焼け止め化粧品、爪化粧品、口唇化粧品、口腔化粧品、入浴用化粧品)
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化粧品の成分用途
pH調整剤
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効能
収斂薬
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主な用途／役割
イソブテン・無水マレイン酸共重合樹脂の架橋剤として使用される。
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使用上の注意
空気中の二酸化炭素を吸収する。
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説明
Calcium Hydroxide is a colorless crystal or white powder,
obtained when CaO (called lime or quicklime) is mixed, or
“slaked” with water. It can also be precipitated by mixing
CaCl2 andNaOH.The nameof the natural,mineral formis
“portlandite”. It is a relatively rare mineral, known from
some volcanic, plutonic, and metamorphic rocks. It has
also been known to be formed in burning coal dumps.
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化学的特性
Calcium hydroxide occurs as a white or almost white, crystalline or
granular powder. It has a bitter, alkaline taste. Calcium hydroxide
readily absorbs carbon dioxide to form calcium carbonate.
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物理的性質
Soft white crystalline powder; hexagonal; density 2.34 g/cm3; slightly bitter taste; loses water when heated at elevated temperatures (580°C); slightly soluble in water; Ksp 1.2x10-14; aqueous solution alkaline; soluble in glycerol and acids; insoluble in alcohol.
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使用
calcium hydroxide is an inorganic base used to adjust the pH of a product, it can also serve as a topical astringent and alkali in solutions or lotions. It can burn the skin and eyes.
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定義
Lime water: A solution of calcium hydroxide
in water. If carbon dioxide is bubbled
through lime water a milky precipitate of
calcium carbonate forms. Prolonged bubbling
of carbon dioxide turns the solution
clear again as a result of the formation of
soluble calcium hydrogencarbonate
(Ca(HCO3)2).
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調製方法
Calcium hydroxide is manufactured by adding water to calcium
oxide, a process called slaking.
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一般的な説明
Odorless white granules. Sinks in water.
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空気と水の反応
Water soluble. The amount of heat generated by hydrolysis may be large.
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反応プロフィール
The nitroparaffins, nitromethane, nitropropane, etc. form salts with inorganic bases such as Calcium hydroxide . The dry salts are explosive [Chem. Eng. news 30:2344 1952]. Bases are chemically similar to sodium hydroxide (NaOH) or sodium oxide (Na2O). They neutralize acids exothermically to form salts plus water. When soluble in water they give solutions having a pH greater than 7.0. Mixing these materials with water can generate troublesome amounts of heat as the base is dissolved or diluted. Bases react with certain metals (such as aluminum and zinc) to form oxides or hydroxides of the metal and generate gaseous hydrogen. Bases may initiate polymerization reactions in polymerizable organic compounds, especially epoxides). They may generate flammable and/or toxic gases with ammonium salts, nitrides, halogenated organics, various metals, peroxides, and hydroperoxides. Materials of this group often serve as catalysts. A strong base. Forms caustic solution in water [Merck 11th ed. 1989].
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危険性
Skin, eye, and upper respiratory tract irri-
tant, avoid inhalation.
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健康ハザード
Dust irritates eyes, nose and throat.
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応用例（製薬）
Calcium hydroxide is a strong alkali and is used as a pharmaceutical
pH adjuster/buffer and antacid in topical medicinal ointments,
creams, lotions, and suspensions, often as an aqueous solution (lime
water). It forms calcium soaps of fatty acids, which produce
water-in-oil emulsions (calamine liniment), and it is also used as a
topical astringent.
Calcium hydroxide is a common cosmetic ingredient in hairstraightening
and hair-removal products, and in shaving preparations.
1) In dentistry, it is used as a filling agent and in dental pastes
to encourage deposition of secondary dentine. Calcium hydroxide
was traditionally used as an escharotic in Vienna Paste.
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农业用途
Calcium hydroxide, [Ca(OH)2], also called slaked lime
or hydrated lime, is a white solid that dissolves
sparingly in water. It is manufactured by adding water to
calcium oxide, a process that emits heat and is known as
slaking.
Calcium hydroxide is a cheap alkali, used for
neutralizing the acidity of acid soils and in the
manufacture of mortar, white wash, bleaching powder
and glass. It is an excellent absorbent for carbon dioxide
to produce insoluble calcium carbonate and has a
neutralizing value of 179%, compared to 100% of pure
calcium carbonate.
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安全性プロファイル
Mildly toxic by
ingestion. A severe eye irritant. A skin,
mucous membrane, and respiratory system
irritant. Mutation data reported. Causes
dermatitis. Dust is considered to be a
significant industrial hazard. A common air
contaminant. Violent reaction with maleic
anhydride, nitroethane, nitromethane,
nitroparaffins, nitropropane, phosphorus.
Reaction with polychloiinated phenols +
potassium nitrate forms extremely toxic
products. See also CALCIUM
COMPOUNDS
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安全性
Calcium hydroxide is used in oral and topical pharmaceutical
formulations. It is mildly toxic by ingestion. In the pure state,
calcium hydroxide is a severe skin, eye, and respiratory irritant, and
it is corrosive, causing burns. Typical exposure limits are TVL
5 mg/m3 in air.
LD50 (mouse, oral): 7.3 g/kg
LD50 (rat, oral): 7.34 g/kg
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職業ばく露
Calcium hydroxide is used in agriculture and in fertilizer manufacture; it is used in the formulation of mortar, plasters, and cements; it is used as a
scrubbing and neutralizing agent in the chemical industry.
For making insecticides, acaricides, and products to control
arthropods
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貯蔵
Calcium hydroxide should be stored in an airtight container, in a
cool, dry, well-ventilated place. Calcium hydroxide powder may be
sterilized by heating for 1 hour at a temperature of at least 1608℃.
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輸送方法
UN3262 Corrosive solid, basic, inorganic, n.o.s.,
Hazard class: 8; Labels: 8-Corrosive material, Technical
Name required
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純化方法
Heat analytical grade calcium carbonate at 1000o during 1hour. Allow the resulting oxide to cool and add slowly to water. Heat the suspension to boiling, cool and filter through a sintered glass funnel of medium porosity (to remove soluble alkaline impurities). Dry the solid at 110o and crush it to a uniformly fine powder. [Ehrlich in Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol I p 934 1963.]
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不和合性
Incompatible with strong acids, maleic anhydride, phosphorus,
nitroethane, nitromethane, nitroparaffins, and nitropropane. Calcium
hydroxide can be corrosive to some metals.
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廃棄物の処理
Landfill or admixture with
acid industrial wastes prior to lagooning
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規制状況(Regulatory Status)
GRAS listed. Accepted for use as a food additive in Europe.
Included in the FDA Inactive Ingredients Database (intravenous and
subcutaneous injections; oral suspensions and tablets; topical
emulsions and creams). Included in parenteral preparations licensed
in the UK.
