カオリン 化学特性,用途語,生産方法
外観
本品は白色～類白色の砕きやすい塊又は粉末で，わずか
に粘土ようのにおいがある．
本品は水，エタノール(99.5)又はジエチルエーテルにほと
んど溶けない．
本品は希塩酸又は水酸化ナトリウム試液に溶けない．
本品は水で潤すとき，暗色を帯び，可塑性となる．
定義
本品は、岩石の化学的及び物理的な風化作用により得られるフィロ珪酸塩鉱物の一種であり、主としてがん水シリカとアルミナからなり、その粒径は2ミクロン以下である。
存在
カオリン鉱物の一種。カオリン石ともいう。火成岩、火砕岩（火山砕屑(さいせつ)岩）の熱水変質鉱物として産するほか、長石、火山ガラスや他のアルミニウムを含む珪(けい)酸塩鉱物の風化物として堆積(たいせき)岩や土壌中に産する。また、熱水鉱脈鉱床の脈石鉱物や花崗(かこう)岩ペグマタイト中にも産する。普通、塊状ないし粉状である。電子顕微鏡で観察すると、六角板状ないし鱗片(りんぺん)状の結晶がみられる。カオリナイトを主とする粘土で不純物の少ないものは、陶磁器や耐火物に利用される。また、製紙原料、化粧品、農薬などの増量剤などにも利用される。名称は、中国のこの鉱物産地に近い小山の名前、高陵（Kauling）がなまってつけられたカオリンに由来する。
アルミナ質粘土鉱物の代表的な種。化学式はAl2(Si2O5)(OH)4で，SiO4四面体層と，AlとOおよびOHの形成する八面体層が交互に積み重なって形成する二層構造をもつ層状結晶構造を示す代表的な結晶である。三斜晶系の場合と単斜晶系に属する結晶構造を示す場合とがある。また同一の化学組成をもち同様な構造をもつ鉱物としてディッカイトdickite，ナクライトnacriteが存在し，いずれも微細な六角板状の結晶となる。
解説
Al4[Si4O10](OH)8．高陵(りょう)石ともいう．層状ケイ酸塩鉱物．岩石の風化や熱水作用による二次鉱物として広く分布する．カオリン粘土の主要鉱物．ディッカイト(dickite)，ナクライト(nacrite)とは多形．ハロイサイト(halloysite)，メタハロイサイトは含水量のさらに多いものである．人工的にはAl2O3-SiO2，またはAl(OH)3-SiO2組成のゲルを250～400 ℃ に保って得られる．三斜晶系，空間群 P 1，格子定数 a0 ＝ 0.515，b0 ＝ 0.895，c0 ＝ 0.739，d001 ＝ 0.715 nm．α 91.8°，β 104.8°，γ 90°．普通，数 μm 以下の微小六角板状結晶．へき開{001}完全．硬度2.61～2.68．密度2～2.5 g cm－3．n 1.553～1.570．複屈折0.006．白色または帯赤褐色．塩酸に溶ける．400～525 ℃ で吸熱の脱水反応を起こし，800 ℃ で完全に脱水する．これをメタカオリナイトという．
森北出版「化学辞典（第2版）
用途
製紙、陶磁器、化粧品、農薬、医薬品
化粧品の成分用途
不透明化剤、滑沢剤、結合剤、抗ケーキング剤、皮膚コンディショニング剤、皮膚保護剤、親水性増粘剤、吸着剤、研磨.スクラブ剤、増量剤
主な用途／役割
エマルション系接着剤、エポキシ樹脂系接着剤、ポリウレタン系接着剤、ゴム系接着剤に使用される。
確認試験
(１) 本品1gを磁製皿にとり，水10mL及び硫酸5mLを加え，
ほとんど蒸発乾固するまで加熱する．冷後，水20mLを加え，
2～3分間煮沸した後，ろ過するとき，残留物は灰色である．
(２) (1)のろ液はアルミニウム塩の定性反応の(1)，
(2)及び(4)を呈する．
純度試験
(１) 液性 本品1.0gを水25mLに加え，よく振り混ぜてろ
過した液のpHは4.0～7.5である．
(２) 酸可溶物 本品1.0gを希塩酸20mLに加え，15分間振
り混ぜた後，ろ過する．ろ液10mLを蒸発乾固し，450～
550℃で恒量になるまで強熱するとき，残留物は0.010g以下
である．
(３) 炭酸塩 本品1.0gを水5mLに加えてかき混ぜた後，
薄めた硫酸(1→2)10mLを加えるとき，泡立たない．
(４) 重金属 本品1.5gに水50mL及び塩酸5mLを加
え，20分間よく振り混ぜながら穏やかに煮沸し，冷後，遠
心分離し，上澄液をとり，沈殿を水10mLずつで2回洗い，
毎回遠心分離し，上澄液及び洗液を合わせ，アンモニア水
(28)を滴加し，沈殿がわずかに生じたとき，強く振り動かし
ながら希塩酸を滴加して再び溶かす．この液に塩酸ヒドロキ
シアンモニウム0.45gを加えて加熱し，冷後，酢酸ナトリウ
ム三水和物0.45g及び希酢酸6mLを加え，必要ならばろ過し，
水10mLで洗い，ろ液及び洗液を合わせ，水を加えて150mL
とする．この液50mLをとり，これを検液とし，試験を行う．
比較液は鉛標準液2.5mLに塩酸ヒドロキシアンモニウム
0.15g，酢酸ナトリウム三水和物0.15g，希酢酸2mL及び水
を加えて50mLとする(50ppm以下)．
(５) 鉄 本品40mgに希塩酸10mLを加え，水浴中
で10分間振り混ぜながら加熱する．冷後，L－酒石酸0.5gを
加え，振り混ぜてL－酒石酸を溶かした後，以下第2法によ
り検液を調製し，B法により試験を行う．比較液には鉄標準
液2.0mLを加える(500ppm以下)．
(６) ヒ素 本品1.0gに水5mL及び硫酸1mLを加え，
砂浴上で白煙を生じるまで加熱し，冷後，水を加えて5mL
とする．これを検液とし，試験を行う(2ppm以下)．
(７) 異物 本品5gをビーカーに入れ，水100mLを加えて
かき混ぜ，砂を残すように傾斜する．更に毎回水100mLを
用いてこの操作を数回繰り返すとき，砂状の残留物を残さな
い．
貯法
容器 密閉容器．
説明
Kaolin or china clay is a naturally occurring, almost white, hydrated aluminum silicate. This material does not exhibit a high degree of slip. Kaolin boasts good absorbency, is dense, and is sometimes used to reduce the bulk densities in loose powder products. It provides a matte surface effect, which can slightly reduce sheen left by some talc products.
化学的特性
Kaolin occurs as a white to grayish-white colored, unctuous powder
free from gritty particles. It has a characteristic earthy or claylike
taste, and when moistened with water it becomes darker in color
and develops a claylike odor.
物理的性質
Sericite is a mineral similar to white mica in shape and composition. It has a very fine grain size and a silky shine. This material is soft and smooth and has a slippery feel on the skin. Sericite may be coated with silicone and other treatments for enhanced water repellency and skin adhesion.
天然物の起源
Kaolin is a naturally occurring clay that is treated for impurities.
使用
kaolin (China clay) is a mixture of various aluminum silicates. It is often used in powders and masks given its absorbent, abrasive, bulking, and opacifying properties. This white, soft powder has good coverage and absorption abilities for both water and oil, making it an appropriate absorber of the oil and sweat secreted by the skin. It adheres well to the skin’s surface, yet is easily removed with normal cleansing procedures. Kaolin is considered a non-comedogenic raw material.
定義
A mixture of clays, quartz,
and feldspar usually containing at least 25%
alumina. Ball and china clays are ordinarily used.
A slip or slurry is formed with water to form a
plastic, moldable mass, which is then glazed and
fired to a hard, smooth solid.
調製方法
Kaolin is a hydrated aluminum silicate obtained by mining naturally
occurring mineral deposits. Large deposits are found in Georgia,
USA and in Cornwall, England.
Mined kaolin is powdered and freed of coarse, gritty particles
either by elutriation or by screening. Impurities such as ferric oxide,
calcium carbonate, and magnesium carbonate are removed with an
electromagnet and by treatment with hydrochloric acid and/or
sulfuric acids.
製造方法
The extraction of KAOLIN (china clay) from its deposits is usually performed in three steps: open-pit mining, mineral processing and beneficiation, and drying.
Open-pit operations require the removal of ground overlying the clay (i.e., overburden). The
exposed clay is then mined by a hydraulic mining process, that is, a high-pressure water jet
from a water cannon called a monitor erodes the faces of the pit. This liberates from the
quarry face the china clay, together with sand and mica. The slurry formed flows to the lowest part of the pit or sink, where it is pumped by centrifugal pumps to classifiers, where
coarse silica sand is removed. The silica sand is later reused for landscape rehabilitation. The
remaining suspension of clay is transported by underground pipeline to the mineral-processing and beneficiation plant, where a series of gravity separation techniques are used to
remove particulate materials such as quartz, mica, and feldspars. Sometimes the purified
clay slurry undergoes an additional chemical bleaching process that greatly improves its
whiteness. The refined clay suspension is then filtrated, and the filtration cake with a moisture content of about 25 wt.% passes through a thermal drier fired by natural gas to yield
a final product with 10 wt.% moisture. The end product is normally sold in pelletized form
with a pellet size ranging from 6 to 12 mm.
適応症
Kaolin is a naturally occurring hydrated
aluminum silicate that is prepared for medicinal
use as a very finely divided powder. The rationale behind
its use in acute nonspecific diarrhea stems from its
ability to adsorb some of the bacterial toxins that often
cause the condition.
世界保健機関（WHO）
Kaolin, a hydrated aluminium silicate, is an absorbent and has
been used to treat diarrhoea because of its ability to bind and inactivate bacterial
toxins. However, it has been shown to induce only a slight change in stool
consistency and there is no evidence that it can reduce the duration or the severity
of diarrhoeal disease. It does not reduce fluid and electrolyte losses. It cannot be
recommended in the treatment of diarrhoea.
一般的な説明
Odorless white to yellowish or grayish powder. Contains mainly the clay mineral KAOLINite (Al2O3 SiO2)2 H2O)2), a hydrous aluminosilicate. KAOLINite has mp 740-1785°C and density: 2.65 g cm-3. KAOLINe is insoluble in water but darkens and develops a earthy odor when wet.
反応プロフィール
KAOLIN is stable and chemically unreactive under ordinary conditions.
危険性
Respirable fraction; questionable carcinogen.
応用例（製薬）
Kaolin is a naturally occurring mineral used in oral and topical
pharmaceutical formulations.
In oral medicines, kaolin has been used as a diluent in tablet and
capsule formulations; it has also been used as a suspending vehicle.
In topical preparations, sterilized kaolin has been used in poultices
and as a dusting powder. Therapeutically, kaolin has been used in
oral antidiarrheal preparations.
工業用途
The name kaolin comes from the two Chinese words kao-ling, meaning high ridge, and was originally a local term used to describe the region from which the clay was obtained. Kaolin (Al
2O
32SiO
22 H
2O) usually contains less than 2% alkalies and smaller quantities of iron, lime, magnesia, and titanium. Because of its purity, kaolin has a high fusion point and is the most refractory of all clays. Lone kaolins are widely used in casting sanitaryware, ceramics, and refractories.
Georgia china clay is one of the most uniform kaolins to be found. Generally speaking, there are two types of Georgia-sourced kaolin, both of which are widely used for casting and other processes. One type imparts unusually high strength and plasticity, and is used for both casting and jiggering where a high degree of workability is required. The other type typically is a fractionated, controlled particle size clay that also behaves well in casting, dries uniformly, and reduces cracking of ware.
副作用
It is almost harmless and is effective
in many cases of diarrhea if taken in large enough
doses (2–10 g initially, followed by the same amount after
every bowel movement). The adsorbents are generally
safe, but they may interfere with the absorption of
some drugs from the GI tract.
安全性
Kaolin is used in oral and topical pharmaceutical formulations and
is generally regarded as an essentially nontoxic and nonirritant
material.
Oral doses of about 2–6 g of kaolin every 4 hours have been
administered in the treatment of diarrhea.
Source
Premier-quality deposits of kaolin such as those mined in Cornwall in the United Kingdom, Georgia and the Carolinas in the southe astern United States, and the Amazon Basin of Brazil.
Other suppliers of quality kaolin include France, Germany, the Czech Republic, Malaysia, and Australia.
貯蔵
Kaolin is a stable material. Since it is a naturally occurring material,
kaolin is commonly contaminated with microorganisms such as
Bacillus anthracis, Clostridium tetani, and Clostridium welchii.
However, kaolin may be sterilized by heating at a temperature
greater than 160°C for not less than 1 hour. When moistened with
water, kaolin darkens and becomes plastic.
Kaolin should be stored in a well-closed container in a cool, dry
place.
不和合性
The adsorbent properties of kaolin may influence the absorption of
other orally administered drugs. Drugs reportedly affected by
kaolin include amoxicillin; ampicillin;cimetidine; digoxin;
lincomycin; phenytoin; and tetracycline. Warfarin absorption by
rat intestine in vitro was reported not to be affected by kaolin.
With clindamycin, the rate (but not the amount) of absorption was
affected by kaolin.
規制状況(Regulatory Status)
Accepted in Europe as a food additive in certain applications.
Included in the FDA Inactive Ingredients Database (oral capsules,
powders, syrups, and tablets; topical preparations). Included in
nonparenteral medicines licensed in the UK.
カオリン 上流と下流の製品情報
原材料
準備製品