CALCIUM CARBONATE PIGMENT FOR THERMOSENSIBLE PAPER, ITS PRODUCTION, COATING COMPOSITION FOR THERMOSENSIBLE PAPER AND THERMOSENSIBLE PAPER

摘要

PURPOSE:To obtain a calcium carbonate pigment for thermosensible paper having high oil-absorption, antifogging property, light-resistance of recorded image, etc., by adding a specific surface-conditioning agent to an aqueous suspension of CaCO3 having a specific BET surface area and stirring the mixture. CONSTITUTION:An aqueous suspension of a calcium carbonate having a BET specific surface area of 17-55m2/g is added with one or more kinds of surface- controlling agents for calcium carbonate selected from alkaline-earth metal hydroxide (e.g. magnesium hydroxide), alkali metal hydroxide (e.g. sodium hydroxide), alkali metal carbonate (e.g. sodium carbonate), alkali metal bicarbonate, sodium aluminate, aluminum acetate and 4-14C aliphatic amine acetic acid salt (e.g. butylamine acetate) and the mixture is stirred to obtain the objective calcium carbonate for thermosensible paper having a solid acidity (y) shown by formula and an oil absorption of 90-220ml/100g (measured by Ogura method).