ジクロロカルシウム

外観

白色, 粉末又は塊

定義

本品は、カルシウムの塩化物であり、次の化学式で表される。

溶解性

水に易溶 (75g/100g水, 20℃)。水に溶けやすく、エタノールにやや溶けやすい。

解説

塩化カルシウム 炭酸カルシウムまたは水酸化カルシウムに塩酸を作用させ濃縮すると得られる．天然には海水中に約0.15％ 存在し，また鉱物としても産出する．工業的には，アンモニアソーダ法の副産物として得られる．無水物は白色の固体で斜方晶系．格子定数a ＝ 0.624，b ＝ 0.643，c ＝ 0.420 nm．融点772 ℃，沸点1600 ℃ 以上．密度2.15 g cm－3．潮解性で吸湿性が大きく乾燥剤に用いられる．水に易溶，種々のアルコール，アセトンに可溶．アンモニアおよびエタノールとはそれぞれCaCl2･8NH3，CaCl2･4C2H5OHのような分子化合物をつくるので，それらの乾燥には適当でない．飽和水溶液から結晶させると30 ℃ 以下では六水和物，30～40 ℃ では四水和物，40 ℃ 以上では二水和物を析出する．175 ℃ で一水和物となり，300 ℃ では無水物を生じる．六水和物と氷とを1.44：1の割合でまぜると，氷晶点は－54.9 ℃ で，寒剤として用いる．

用途

汎用試薬、合成原料。

用途

汎用試薬。

用途

粉じん防止剤、防じん剤,氷結防止剤,石灰塩原料,紙?織物のサイズ剤?電子セラミック材料?金属石けん原料,医薬,医薬部外品,食品添加物,農薬(植物成長調整剤)

用途

日本薬局方には塩化カルシウムと塩化カルシウム注射液が収載されている。医療用には2％または3％の水溶液、および電解質補正用に0.5モルの水溶液が使われる。また、リンゲル液の組成としても含まれている。骨格や歯牙(しが)の強化、発育促進などを目的としてカルシウムの補給に使われるが、注射液は栄養剤としてよりも治療薬として臨床的に使われることが多い。すなわち、カルシウムの作用が血液凝固促進因子として、また筋収縮にも関係することから、低カルシウム血症性テタニーをはじめ、けいれん性素因や出血性素因のほか、じんま疹(しん)、湿疹、薬疹、瘙痒(そうよう)症などの皮膚疾患などに使われる。筋肉注射をすると局所壊死(えし)の危険があるため、静脈注射を行う。

化粧品の成分用途

親水性増粘剤、収れん剤

使用上の注意

潮解性がある。

化学的特性

Calcium chloride, CaC12, is colorless deliquescent solid that is soluble in water and ethanol. It is formed from the reaction of calcium carbonate and hydrochloric acid or calcium hydroxide and ammonium chloride. It is used in medicine, as an antifreeze, and as a coagulant.

物理的性質

White crystal, powder or flake; highly hygroscopic; the compound and its solutions absorb moisture from the air at various rates depending on calcium chloride concentrations, relative humidity and vapor pressure of water in the air, temperature, surface area of exposed material, and the rate of air circulation; at 40% and 95% relative humidity and 25°C, one gram anhydrous calcium chloride may absorb about 1.4 g and 17 g water, respectively. (Shearer, W. L. 1978 . In Kirk-Othmer Encyclopedia of Chemical Technology, 3rd ed., vol. 4, pp. 432-6. New York: Wiley Interscience); density 2.15, 2.24, 1.85, 1.83 and 1.71 g/cm3 for the anhydrous salt and its mono-, di-, tetra- and hexahydrates, respectively; anhydrous salts melts at 772°C, while the mono-, di-, tetra- and hexahydrates decompose at 260°, 175°, 45.5° and 30°C, respectively; the anhydrous salt vaporizes at 1,935°C; highly soluble in water, moderate to high solubility in alcohol.
Densities and crystallizing temperatures of commercial calcium chloride solutions (Courtesy Allied Corp.):

天然物の起源

Calcium chloride may be found in nature as the mineral tachhydrite, CaCl₂?2MgCl₂?12H₂O. It also is found in other minerals. Its concentration in sea water is about 0.15%.
Calcium chloride has several industrial applications. The major applications of this compound are in deicing of roads, dust control, imparting stability to roads and buildings, and to improve traction in tractor tires. It is mixed with ice to make freezing mixtures. Hexahydrate mixed with crushed ice can lower the temperature of the cooling bath to below -50°C. It also is used as a desiccant for dehydrating gases and liquids. It is added to cement in various proportions to manufacture different types of concrete. Other uses are in adhesives, to lower gel temperatures, and as a calcium source in liquid feed supplements for dairy cattle. Also, the compound is used to control particle size development and reduce coalescence in plastics.

使用

Calcium chloride is highly hygroscopic and is often used as a desiccant.

製造方法

Calcium chloride is obtained as a by-product in the manufacture of sodium carbonate (soda ash) by ammonia-soda (Solvay) process. The process involves the reaction of sodium chloride with calcium carbonate and ammonia. Calcium chloride is currently produced in bulk amounts by evaporation of natural underground brines. In the laboratory, calcium chloride can be prepared by treating limestone with hydrochloric acid followed by evaporation of solution to obtain crystals. The crystals are dehydrated to obtain anhydrous salt. Calcium oxide or hydroxide may be used instead of carbonate.

定義

calcium chloride: A white deliquescentcompound, CaCl₂, which issoluble in water; r.d. 2.15; m.p.782°C; b.p. >1600°C. There are anumber of hydrated forms, includingthe monohydrate, CaCl₂.H₂O, the dihydrate,CaCl₂.2H₂O (r.d. 0.84), andthe hexahydrate, CaCl₂.6H₂O (trigonal;r.d. 1.71; the hexahydrate loses4H₂O at 30°C and the remaining2H₂O at 200°C). Large quantities of itare formed as a byproduct of theSolvay process and it can be preparedby dissolving calcium carbonateor calcium oxide in hydrochloricacid. Crystals of the anhydrous saltcan only be obtained if the hydratedsalt is heated in a stream of hydrogenchloride. Solid calcium chloride isused in mines and on roads to reducedust problems, whilst the molten saltis the electrolyte in the extraction ofcalcium. An aqueous solution of calciumchloride is used in refrigerationplants.

調製方法

Calcium chloride is a principal byproduct from the Solvay process.

一般的な説明

Calcium Chloride (CaCl₂) is a water soluble ionic crystal with a high enthalpy change of solution. It is majorly derived from limestone and is a by-product of the Solvay process. It is an anhydrous salt that has a hygroscopic nature and can be used as a desiccant.

空気と水の反応

Deliquescent. Water soluble. Adding Calcium chloride to hot water caused violent boiling, [MCA Case History No. 69].

反応プロフィール

Bromine trifluoride rapidly attacks the following salts: barium chloride, cadmium chloride, Calcium chloride, cesium chloride, lithium chloride, silver chloride, rubidium chloride, potassium bromide, potassium chloride, potassium iodide, rhodium tetrabromide, sodium bromide, sodium chloride, and sodium iodide [Mellor 2 Supp. 1:164, 165 1956]. Long term exposure of Calcium chloride solution upon a zinc coated galvanized iron vessel caused slow evolution of hydrogen which ignited and exploded [Bretherick, 5th Ed., 1995].

健康ハザード

Inhalation causes irritation of nose and throat. Ingestion causes irritation of mouth and stomach. Contact with eyes (particularly by dust) causes irritation and possible transient corneal injury. Contact of solid with dry skin causes mild irritation; strong solutions can cause marked irritation, even a superficial burn.

応用例（製薬）

The main applications of calcium chloride as an excipient relate to its dehydrating properties and, therefore, it has been used as an antimicrobial preservative, as a desiccant, and as an astringent in eye lotions.
Therapeutically, calcium chloride injection 10% (as the dihydrate form) is used to treat hypocalcemia.

安全性プロファイル

Moderately toxic by ingestion. Poison by intravenous, intramuscular, intraperitoneal, and subcutaneous routes. Human systemic effects: dermatitis, changes in calcium. Questionable carcinogen with experimental tumorigenic data. Mutation data reported. Reacts violently with (B203 + CaO), BrF3. Reaction with zinc releases explosive hydrogen gas. Catalyzes exothermic polymerization of methyl vinyl ether. Exothermic reaction with water. When heated to decomposition it emits toxic fumes of Cl-. See also CALCIUM COMPOUNDS and CHLORIDES.

安全性

Calcium chloride is used in topical, ophthalmic, and injection preparations. The pure form of calcium chloride is toxic by intravenous, intramuscular, intraperitoneal, and subcutaneous routes, and moderately toxic by ingestion, causing stomach and heart disturbances. It is a severe eye irritant and can cause dermatitis.
LD₅₀ (mouse, IP): 0.21 g/kg
LD₅₀ (mouse, IV): 0.042 g/kg
LD₅₀ (mouse, oral): 1.94 g/kg
LD₅₀ (mouse, SC): 0.82 g/kg
LD₅₀ (rat, IM): 0.025 g/kg
LD₅₀ (rat, IP): 0.26 g/kg
LD₅₀ (rat, oral): 1.0 g/kg
LD₅₀ (rat, SC): 2.63 g/kg

職業ばく露

Calcium chloride is used as road salt for melting snow, a drying agent in desiccators, for dehydrating organic liquids and gases, in refrigeration brines and antifreeze, as a dust-proofing agent, food additives, concrete hardening accelerator, and others. May react with strong oxidizers.

貯蔵

Calcium chloride is chemically stable; however, it should be protected from moisture. Store in airtight containers in a cool, dry place.

輸送方法

There are no label or maximum shipping quantity requirements set by DOT.

純化方法

It is available as fused granules or cubic crystals. It is very hygroscopic, very soluble in H2O (exothermic), and EtOH. Store it in a tightly closed container. [Ehrlich in Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol I p 931 1963.]

不和合性

Calcium chloride is incompatible with soluble carbonates, phosphates, sulfates, and tartrates. It reacts violently with bromine trifluoride, and a reaction with zinc releases explosive hydrogen gas. It has an exothermic reaction with water, and when heated to decomposition it emits toxic fumes of chlorine.

規制状況(Regulatory Status)

GRAS listed. Included in the FDA Inactive Ingredients Database (injections, ophthalmic preparations, suspensions, creams). Included in medicines licensed in the UK (eye drops; intraocular irrigation; vaccines; injection powders for reconstitution; nebulizer solution; oral suspension).