クロム酸亜鉛 化学特性,用途語,生産方法
解説
ストロンチウムクロメート、バリウムクロメートなどとともに、クロメート(クロム酸塩)系さび止め顔料である。すなわち、可溶性のクロム酸イオンCrO42-を徐々に放出することによって、金属面を不動態化するものである。ステンレス鋼の場合は、CrO42-によって鉄面に薄い酸化被膜を生成し、鉄イオンが溶出できない状態にする。さびを促進する原因となる硫酸イオンSO42-や塩素イオンCl-を含まない原料を使用することが必要で、このため酸化亜鉛を用いる。これを水中に分散させ、重クロム酸カリウム、無水クロム酸を加え、生じた沈殿を乾燥する。ジンククロメートには2種類あり、ZPCは溶解度を大きくし、速効性をねらったもので、展色料(展色剤)には耐水性の合成樹脂系のものがよい。ZTOは亜鉛イオンによる金属せっけんの生成と可溶性分を小さくすることを目的としているので、展色料には一般のボイル油なども使用できる。[大塚 淳]
小学館 日本大百科全書(ニッポニカ) )
化学的特性
Zinc chromate is a yellow crystalline powder.
使用
Zinc chromate is used in pigments, rubber, linoleum manufacturing, metal surface treatment, electroplating intermediates, research and development. It finds its application as an useful metal for preventing corrosion when applied to other metals.
一般的な説明
Odorless yellow solid. Sinks in water.
反応プロフィール
Oxidizing agents, such as ZINC CHROMATE, can react with reducing agents to generate heat and products that may be gaseous (causing pressurization of closed containers). The products may themselves be capable of further reactions (such as combustion in the air). The chemical reduction of materials in this group can be rapid or even explosive, but often requires initiation (heat, spark, catalyst, addition of a solvent). Explosive mixtures of inorganic oxidizing agents with reducing agents often persist unchanged for long periods if initiation is prevented. Such systems are typically mixtures of solids, but may involve any combination of physical states. Some inorganic oxidizing agents are salts of metals that are soluble in water; dissolution dilutes but does not nullify the oxidizing power of such materials. Organic compounds, in general, have some reducing power and can in principle react with compounds in this class. Actual reactivity varies greatly with the identity of the organic compound. Inorganic oxidizing agents can react violently with active metals, cyanides, esters, and thiocyanates.
健康ハザード
Inhalation of dust causes irritation of nose and throat. Ingestion can cause irritation or corrosion of the alimentary tract, circulatory collapse, and toxic nephritis. Contact with eyes or skin causes irritation.
安全性プロファイル
Confirmed human
carcinogen producing lung tumors. A
poison via intravenous route. Human
mutation data reported. See also
CHROMIUM COMPOUNDS and ZINC
COMPOUNDS.
職業ばく露
Zinc chromate is used as an anticorrosion
pigment in primers and as a coloring agent;
as a pigment in surface coatings and linoleum; to impart
corrosion resistance to epoxy laminates.
輸送方法
UN3288 Toxic solids, inorganic, n.o.s., Hazard
Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name
Required. UN3077 Environmentally hazardous substances,
solid, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous hazardous
material, Technical Name Required.
不和合性
An oxidizer; reacts with reducing agents;
combustibles, organic materials.
クロム酸亜鉛 上流と下流の製品情報
原材料
準備製品