| 摘要 |
PROBLEM TO BE SOLVED: To provide a calcium carbonate-silica composite material which has high oil absorbing property so as to improve printability and high bulking effect on paper when it is used as a filler in the paper. SOLUTION: The calcium carbonate-silica composite material is characterized in that (1) the molar ratio of calcium carbonate to silica is within a range of 25:75 to 40:65, and (2) in the case when its pore radius r is expressed by formula (I) and the pore volume Va is measured by a mercury penetration method within a range of a of -3 to 23, the comparison of the pore volume Va in each pore radius range partitioned so that the difference between the values of a is 1 shows that the range of pore radius where Va is maximum is within a partition range where a is >12 and≤16, and the total pore volume of pores each having a pore radius at which a is≤16 is within a range of 1.6-2.5 cc/g. The calcium carbonate-silica composite material is produced by mixing sodium silicate with a slurry containing calcium chloride and calcium sulfate in a prescribed ratio to obtain calcium silicate and reacting the calcium silicate with carbon dioxide. COPYRIGHT: (C)2009,JPO&INPIT
|
