Kaolin, delaminated clay

Chem. Descrip. Delaminated kaolin clay CAS 1332-58-7 EINECS/ELINCS 296-473-8 Uses Filler, pigment for paper coatings, esp. merchant grade papers, label and glossy cover stock Features Easy glossing... 

Astra-Fil. [ECCIntT.] Kaolin delaminated filling clay. 

Kaolin deposits are cored and analyzed before mining to determine quality. Mined clays are then either wet or dry processed by air floatation or water fractionation. Surface-modified clays can be made by treating standard, delaminated, and calcinated grades with surface modifiers. The treatment can be performed by either the supplier or the end user. These surface modifiers include silane, titanate, polyester, and metal hydroxide. The objective of these surface treatments is to increase filler loadings and/or improve physical properties such as melt viscosity, thermal stability, and modulus without loss of physical characteristics. Electrical applications represent the largest use of surface-modified kaolin in plastics. 

Delaminated kaolins differ from the standard water-washed grades in that they are thin platelets of varying widths, and they are devoid of stacks and ultrafines. Delaminated clays can be supplied in a variety of particle sizes and shapes. At... 

The United States is the leading supplier of kaolin cl, with about 40% of world production. Second largest is the United Kingdom with about 12%. US annual production capacity of 10 million metric tons is comprised of 40% water-washed, 15% airfloated, 13% calcined, and 10% delaminated clay. The major worldwide use for kaolin is in paper. In the US 40% of kaolin consumption is for coating and filling paper. Much lower but still substantial... 

Paper fillers - High-brightness, low-abrasion airfloated, water-washed and delaminated kaolins are used as pulp extenders in acid-sized paper, where they improve opacity, smoothness and ink receptivity. Partially calcined clay is used as a Ti02 extender. 

Rubber - About 80% of the kaolin for rubber is airfloated hard clay. Water-washed and delaminated clays are used for further improved color, physical propeties, and abrasion resistance. Calcined and smface-treated clays are used for improved electrical properties and ease of extrusion. 

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