초록

The invention relates to a filler used in paper manufacture and mainly consisting of calcium carbonate, and to a procedure for producing the filler. The filler consists of porous aggregates formed by precipitated calcium carbonate particles. In the procedure, calcium carbonate is precipitated.

대표청구항 ▼

1. A method for producing filler for use in paper manufacture, the method comprising steps of: (a) refining cellulose fibre, mechanical pulp fibre, or mixture of mechanical pulp fibre into fibrils, wherein: (i) the fibrils having a thickness of between 0.1 μm and 2 μm, and a length of between 1

1. A method for producing filler for use in paper manufacture, the method comprising steps of: (a) refining cellulose fibre, mechanical pulp fibre, or mixture of mechanical pulp fibre into fibrils, wherein: (i) the fibrils having a thickness of between 0.1 μm and 2 μm, and a length of between 10 μm and 400 μm; and (ii) the fibrils being detached from fibers; and (b) chemically precipitating calcium carbonate onto the surface of the fibrils to provide a porous aggregate of calcium carbonate precipitated onto the surface of fibrils, wherein: (i) the calcium carbonate on the fibrils have a diameter of between 0.2 μm and 3 μm. 2. A method according to claim 1, wherein the step of precipitating calcium carbonate onto the surface of the fractionated fibrils fraction comprises reacting calcium hydroxide and carbon dioxide. 3. A method according to claim 2, wherein the mass ratio of calcium hydroxide and fibrils is 0.1:1 to 20:1. 4. A method according to claim 2, wherein the mass ratio of calcium hydroxide and fibrils is 1.4:1 to 4:1. 5. A method according to claim 1, wherein the step of precipitating calcium carbonate onto the surface of the fractionated fibrils fraction comprises reacting calcium chloride and sodium carbonate. 6. A method according to claim 5, wherein the mass ratio of calcium chloride to fibrils is between 0.15:1 and 30:1. 7. A method according to claim 5, wherein the mass ratio of calcium chloride to fibrils is between 2.1:1 and 6:1. 8. A method according to claim 1, wherein said step of precipitating calcium carbonate onto the surface of the fractionated fibrils comprises providing a concentration of fibrils of 0.001 wt. % and 18 wt. %. 9. A method according to claim 1, wherein said step of precipitating calcium carbonate onto the surface of the fractionated fibrils comprises providing a concentration of fibrils of 0.4 wt. % to 10 wt. %. 10. A method according to claim 1, wherein the fractionated fibrils fraction has an average length of between 10 μm and 150 μm. 11. A method according to claim 1, further comprising a step of screening the fibrils through a 200 mesh wire. 12. A method according to claim 1, wherein the step of precipitating comprising precipitating at a temperature of between 5° C. and 150° C. 13. A method according to claim 1, wherein the step of precipitating comprising precipitating at a temperature of between 10° C. and 90° C. 14. A method according to claim 1, wherein the step of precipitating comprising precipitating at a temperature of between 15° C. and 80° C. 15. A method according to claim 1, wherein the step of precipitating calcium carbonate onto the surface of the fractionated fibrils comprises providing a concentration of fibrils of 0.0001 wt. % and 18 wt. %. 16. A method according to claim 1, wherein said step of precipitating calcium carbonate onto the surface of the fractionated fibrils comprises providing a concentration of fibrils of 0.4 wt. % to 10 wt. %. 17. Porous aggregate prepared according to the method of claim 1.