せっけん 化学特性,用途語,生産方法
解説
せっけん，もっとも古くから知られている界面活性剤で、広義では脂肪酸、樹脂酸、ナフテン酸などの金属塩の総称であるが、通常、高級脂肪酸（炭素数6以上、実用は炭素数12～18）のナトリウム塩（ソーダせっけん）、カリウム塩（カリせっけん）などのアルカリ金属塩をいう。ほかの金属塩は金属せっけんとよばれ、区別される。せっけんは皮膚の垢(あか)やほこりなどの汚れ、衣類に付着した固体汚れ、油性汚れなどを取り除く洗浄剤として用いられる。
性質
せっけんの分子は、炭化水素の長い鎖でできた疎水性の部分と、カルボキシ基（カルボキシル基）がアルカリ金属と結合した親水性の部分からなっており、典型的な陰イオン性界面活性剤である。したがってその水溶液は、水の表面張力、界面張力を低下させ、起泡力、乳化力、可溶化力をもち、強力な洗浄作用を示す。
製法
せっけんは、油脂をカ性アルカリでけん化するか、あるいは脂肪酸をアルカリで中和して製造する。油脂または脂肪酸からせっけん生地をつくる工程と、生地から各種製品をつくる加工工程とからなっている。
使用
According to an ancient Roman legend, soap got its name from Mount
Sapo, where animals were sacrificed. Rain washed a mixture of melted
animal fat or tallow and wood ashes down into the clay soil along the Tiber River. It was found that this clay mixture cleaned the washed
clothes with much less effort.
The term soap is a class name for the sodium and potassium salts of
fatty acids. These fatty acids were found in animal fats and in plant oils
such as coconut oil, palm oil, olive oil, castor oil, or cottonseed oil.
Soaps are manufactured from a renewable source. The triglycerides (or
triesters of fatty acids) are the raw material for the production of soap.
The triglycerides occur widely in plants and animals.
Tallow and coconut oil are the principal fatty materials in soap making
in the United States. The palm oils, palm kernel oil, and their derivatives
are used in soap manufacture in many other parts of the world.
Greases, obtained from hogs and smaller domestic animals, are the
second most important source of glycerides of fatty acids. Coconut oil has
long been important in soap making. The soap from coconut oil is firm
and lathers well. It contains a large amount of the desired glycerides of
lauric and myristic acids [1-6].
The soap maker represents one of the larger consumers of chemicals,
especially caustic soda, salt, soda ash, caustic potash, sodium silicate,
sodium bicarbonate, and trisodium phosphate. Builders are inorganic
chemicals added to soap. In particular, tetrasodium pyrophosphate and
sodium tripolyphosphate were usually effective soap builders [1-6].
定義
(1) The water-soluble reaction product of
a fatty acid ester and an alkali (usually sodium
hydroxide), with glycerol as by-product. For the
reaction, see saponification. A soap is actually a spe-
cific type of salt, the hydrogen of the fatty acid being
re
せっけん 上流と下流の製品情報
原材料
準備製品