Patent attributes
The present invention provides a low-density neutral paper offering excellent opacity, opacity after printing and other advantageous printability properties despite high bulk, by containing, as a filler, precipitated calcium carbonate-silica composite having an average particle size of 30 μm or less and produced by neutralizing a mixture of precipitated calcium carbonate and alkaline silicate to pH 7 to 9, wherein the ratio of precipitated calcium carbonate to silica (precipitated calcium carbonate/silica) is 30/70 to 70/30 in solid content by weight and the surface of precipitated calcium carbonate particles is covered with silica. In particular, the present invention provides a low-density printing paper, or an electrophotographic transfer paper offering excellent stiffness and copier suitability, by means of adjusting the filler content in paper to a range of 1 to 25 solid content percent by weight, or provides a neutral newsprinting paper by means of adjusting the filler content in paper to a range of 0.1 to 25 solid content percent by weight.
