Amphoteric calcium carbonate filling and preparation method thereof

Abstract

The present invention involves new amphiprotic calcium carbonate filler and the preparation method. The raw materials components are: protein water solution which protein content weight percentage is 0. 01% - 8%; mixture which molar ratio of calcii chloridum and carbonas is 0. 8 - 2:1; the weight ratio of protein and carbonate is 0. 01-4:1. On the role of specific matrix, the mixing reaction of calcium salt and carbonates prepares amphiprotic calcium carbonate with different shapes and controllable grain size, the two phases are prepared after reaction: upper liquid phase containing chlorinated salt and lower white calcium carbonate solid phase containing certain matrix. The shape of calcium carbonate includes petal-shaped, spindle, spherical and piece and so on. The amphiprotic calcium carbonate filler can be used for paper making filler to improve the combination between fiber and filler and between fibers, increase the retention ratio of filler and fine fiber in pulp; and increase the filler content and improve the quality of the paper.

Description

technical field [0001] The invention belongs to the field of paper-making additives, and in particular relates to an amphoteric calcium carbonate filler and a preparation method thereof, in particular to a method for preparing a protein-modified calcium carbonate additive by utilizing protein and inorganic substances. Background technique [0002] Calcium carbonate is an important paper-making filler. The use of fillers in paper mills can reduce production costs and energy consumption. The filling of calcium carbonate between paper fibers can improve the opacity, whiteness, softness and gloss of paper, and provide the necessary performance and end-use characteristics. However, due to the physical adsorption of calcium carbonate on the paper fibers, the active surface for bonding between fibers is reduced, not only the strength of the paper is reduced, the demand for sizing is increased, and the loss rate of calcium carbonate is large. [0003] By adding polyelectrolyte, the...

AI Technical Summary

Problems solved by technology

However, the adsorption of cationic polymers cannot fully compensate the demand for the surface charge of fibers and fillers. When the amount of calcium carbonate filler is 30%, no matter how much cationic polymer is added, the highest retention rate of fillers may reach 88%.

However, sharing anionic and cationic polyacrylamide can produce excellent retention effect; the synergistic retention effect of cationic starch and cationic polyacrylamide can make the retention rate of filler close to 100%, but the sharing of the two will cause Affects the ability of starch to increase paper dry strength