四ホウ酸ナトリウム（無水物） 化学特性,用途語,生産方法
外観
白色, 顆粒～粉末
溶解性
うすい鉱酸及び熱水にやや溶けやすい。
解説
Na2B4O7(201.22)．無水物および数種類の水和物がある．天然に産出するホウ砂は，Na2B4O7･10H2Oとみなされる．このほか，カーン石(kernite)(四水和物)，チンカルコ石(tincalconite)(五水和物)などがある．ホウ砂の水溶液から，60 ℃ 以下で十水和物，60 ℃ 以上で五水和物が析出する．十水和物結晶を100 ℃ で加熱脱水すると五水和物になり，125 ℃ で二水和物，180 ℃ で一水和物，約350 ℃ で無水塩となる．無水塩はガラス状の固体．密度2.37 g cm－3．融点741 ℃．工業的な用途に用いるホウ砂は，天然産のホウ砂を精製して用いるほか，各種のホウ酸塩鉱物を粉砕し，水，ソーダ灰などを加え，加圧，加熱してつくられる．十水和物(ホウ砂)は単斜晶系．密度1.723 g cm－3．平面三角形型のBO3 2個と正四面体型BO4 2個が結合してできた陰イオンで，構造上はNa2[B4O5(OH)4]･8H2Oである．四水和物(kernite)は単斜晶系．密度1.953 g cm－3．構造式Na2[B4O6(OH)2]･3H2Oで，正四面体型のBO4と平面三角形型のBO3が酸素共有で鎖状につながった構造．無水塩は三方晶系で，BO3とBO4が，酸素共有で三次元的に結合している．工業的に，ホウ酸，そのほか多くの物質の製造原料になる．ホウ砂を溶融した小球に金属塩をつけて再溶融すると，金属特有の色が現れる．これをほう砂球反応といい，定性分析に利用される．ホウ砂は，ホウロウ，ガラス，陶磁器のうわぐすりに用いられるほか，はんだ付け用融剤，洗剤，染色，皮なめし，防炎剤，木などの防腐・防食剤，農薬や殺虫剤(ゴキブリ用など)にも用いられる．[CAS 1303-96-4:十水和物][CAS 12045-87-3:四水和物][CAS 1330-43-4:無水塩]
森北出版「化学辞典（第2版）
用途
ホウ素の原料鉱石として工業的に使用されるほか、以下のようにホウ砂そのものの特性を利用した様々な用途がある。
これは多くの金属酸化物を融解する性質を持つため、融剤として使われるほか、このとき金属によって特有の色を呈するため、定性分析や陶芸用の釉薬溶解剤として使われる（硼砂球反応）。
ガラスに混ぜると熱衝撃や化学的浸食に強いホウケイ酸ガラスとなるため、耐熱ガラスなどの原料となる。 水溶液は弱アルカリ性となり、洗浄作用?消毒作用があるため洗剤や防腐剤などに使われる。またホウ酸と同様に、目の洗浄?消毒に用いられる。また、銀塩写真の現像液にアルカリ調整剤として添加される。日本の国産の写真用ホウ砂（10水塩）とアメリカ産のホウ砂（7水塩）では結晶水の数が異なるため、同じ量で現像液を調合した場合にpH値がやや異なり、現像感度に差異が生じるので注意が必要である。
用途
ガラス繊維、セラミック、接着剤
用途
蛍光X線分析用の試料調製用。
用途
融剤、窯業原料。
化学的特性
Sodium borate, Na2B407.10H20, also known as sodium tetraborate and sodium pyrobomte, is a white crystalline powder that melts at 120°C (248 °F). Sodium borate in its natural impure form is also known as borax, Borax is a noncombustible (an inherent fire retardant), bluish-gray or green, odorless crystalline powder or granules. Sodium borate is used in glass and ceramic enamel mixes,detergents, fertilizers, pharmaceuticals, and photograph.
使用
Sodium Tetraborate, is an important boron compound, which has a wide variety of applications. It is a component of many detergents, cosmetics, and enamel glazes. It is also used to make buffer solutions in biochemistry, as a fire retardant, as an anti-fungal compound for fiberglass, as a flux in metallurgy, neutron-capture shields for radioactive sources, a texturing agent in cooking, and as a precursor for other boron compounds.
調製方法
Anhydrous borax is produced from borax through high
temperature fusion. On cooling, the clear, glass-like material
is ground into fine white granules. Because of its higher bulk
density, it is preferred where storage space is limited. It is
used principally in the manufacture of glass, ceramics, and
enamel.
一般的な説明
Pale yellow solid or thick liquid with a faint odor of detergent. Mixes with water. Soap bubbles may be produced.
空気と水の反応
Water soluble.
反応プロフィール
SODIUM PEROXOBORATE is incompatible with the following: Zirconium, strong acids, metallic salts . The true peroxoborate has been reported to detonate on light friction. The common "tetrahydrate" is not a peroxoborate, Sodium tetraborate is relatively stable under mild grinding with other substances.
健康ハザード
No adverse effects from inhaling borax have been reported. Ingestion may cause acute or chronic effects; initial symptoms are nausea, vomiting, and diarrhea; these may be followed by weakness, depression, headaches, skin rashes, drying skin, cracked lips, and loss of hair; shock may follow ingestion of large doses and may interfere with breathing. Eye contact with powder or solutions may cause irritation; no chronic effects have been recognized, but continued contact should be avoided. Local skin irritation may result from contact with powder or strong solutions; the latter may cause chronic dermatitis on prolonged contact, and if skin is broken, enough boron may be absorbed to cause boron poisoning (symptoms are similar to those for ingestion).
农业用途
Sodium tetraborate, also called borax, sodium borate, sodium pyroborate and sodium tetraborate decahydrate (Na2B4O7.10H2O) is a type of borate, and is used as a fertilizer to reduce boron deficiency. It is a white salt, finely ground for fertilizer application.
Sodium tetraborate(Na2B4O7) and sodium metaborate (Na2B2O4) are non-selective, taken up by roots, and have an unknown mechanism of action. Boron accumulates in reproductive structures after translocation from roots. Boron compounds are used for long-term, nonselective weed control in industrial and power line areas in combination with triazine and urea herbicides.
安全性プロファイル
A nuisance dust.
Experimental reproductive effects. When
heated to decomposition it emits toxic
vapors of B.
職業ばく露
Borax is used as a soldering flux,
preservative against wood fungus; and as an antiseptic.
Used in ant poisons, for fly control around refuse and
manure piles, as a larvicide. It is used in the manufacture
of enamels and glazes, fiberglass insulation; sodium perborate
bleach; in tanning, cleaning compounds; for fireproofing
fabrics and wood; and in artificial aging of
wood.
純化方法
Most of the water of hydration is removed from the decahydrate (see below) by evacuation at 25o for three days, followed by heating to 100o and evacuation with a high-speed diffusion pump. The dried sample is then heated gradually to fusion (above 966o), allowed to cool gradually to 200o, then tranferred to a desiccator containing P2O5 [Grenier & Westrum J Am Chem Soc 78 6226 1956]. [Becher in Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol I pp 794-795 1963.]
不和合性
Dissolves in water forming a basic solution.
Boron dust may form explosive mixture with air.
Contact with strong oxidizers may be violent. Boron is
incompatible with ammonia, bromine tetrafluoride, cesium
carbide, chlorine, fluorine, interhalogens, iodic acid, lead
dioxide, nitric acid, nitric oxide, nitrosyl fluoride, nitrous
oxide, potassium nitrite, rubidium carbide, silver fluoride.
廃棄物の処理
Borax, dehydrated: The material
is diluted to the recommended provisional limit
(0.10 mg/L) in water. The pH is adjusted to between 6.5
and 9.1 and then the material can be discharged into sewers
or natural streams.
四ホウ酸ナトリウム（無水物） 上流と下流の製品情報
原材料
準備製品