Abstract
A new method for analyzing the coated clays of the clay-coated papers is reported. It was found that the coated clays were peeled off quantitatively by submerging the coated papers into the concentrated sulfuric acid during 1015 seconds. The peeled off clay was subjected to the X-ray diffraction analysis. The amount of the coated clay was obtained from the difference in ash content between the coated paper and the base paper. This method was applied to the analyris of the commercial coated papers and gave satisfactory reults.
