Method of preparing poly-silicic-ferric coagulant (PSFC) for electrostatic charge image developing toner
Provided is a method of preparing a poly-silicic-ferric coagulant (PSFC) having a controlled aggregating strength. In particular, according to an embodiment, provided is a method of preparing a PSFC that may effectively suppress both formation of fine toner particles having a particle size that is smaller than a desired particle size and formation of coarse toner particles having a particle size that is greater than the desired particle size, wherein the PSFC for a toner is used in preparation of a toner by using an emulsion aggregation (EA) method. The PSFC for a toner prepared by using the method, according to an embodiment, significantly exhibits a controlled aggregating strength, and thus a viscosity of an emulsion aggregation solution for the toner preparation is appropriate, which results in suppressing production of fine toner particles and coarse toner particles. In this regard, a toner preparation yield may improve.
1. A method of producing a poly-silicic-ferric coagulant, the method comprising:
providing a silicic acid aqueous solution having a silicon content, and polymerizing silicic acid in the silicic acid aqueous solution for a polymerization time to form a polymerized silicic acid; and
mixing iron ions and the polymerized silicic acid to produce the coagulant, wherein
the silicon content, a pH of the silicic acid aqueous solution at a start of the polymerizing, and the polymerization time satisfy:
6.20≤log e T −(11.7−3.0×pH−2.6×log e 2.139 C )≤6.65
where T is the polymerization time in hours, and C is the silicon content in wt % based on 100 wt % of a total weight of the silicic acid aqueous solution,
the pH of the silicic acid aqueous solution at the start of the polymerizing is in a range of about 3.5 to about 5.0,
the silicon content is in a range of about 2.9 wt % to about 7.0 wt % based on 100 wt % of the total weight of the silicic acid aqueous solution, and
in the mixing, the iron ions are added to silicic acid aqueous solution in an amount such that a molar ratio of iron atoms to silicon atoms in the produced coagulant is in a range of about 1.1:1 to about 1:1.
2. The method of claim 1 , wherein the silicon content is below 3.5 wt % based on 100 wt % of the total weight of the silicic acid aqueous solution.
3. The method of claim 1 , wherein a pH of the silicic acid aqueous solution during the polymerizing is in a range of about 3.5 to about 5.0.
4. A method of producing a toner using a poly-silicic-ferric coagulant, comprising:
producing the coagulant by a method including
providing a silicic acid aqueous solution having a silicon content, and polymerizing silicic acid in the silicic acid aqueous solution for a polymerization time to form a polymerized silicic acid; and
mixing iron ions and the polymerized silicic acid to produce the coagulant, wherein
the silicon content, a pH of the silicic acid aqueous solution at a start of the polymerizing, and the polymerization time satisfy:
6.20≤log e T −(11.7−3.0×pH−2.6×log e 2.139 C )≤6.65
where T is the polymerization time in hours, and C is the silicon content in wt % based on 100 wt % of a total weight of the silicic acid aqueous solution,
the pH of the silicic acid aqueous solution at the start of the polymerizing is in a range of about 3.5 to about 5.0,
the silicon content is in a range of about 2.9 wt % to about 7.0 wt % based on 100 wt % of the total weight of the silicic acid aqueous solution, and
in the mixing, the iron ions are added to silicic acid aqueous solution in an amount such that a molar ratio of iron atoms to silicon atoms in the produced coagulant is in a range of about 1.1:1 to about 1:1; and
producing the toner by emulsion aggregation performed using the coagulant, the toner comprising 7 wt % or less of particles having a particle size greater than 16 μm.
5. The method according to claim 4 , wherein the producing the toner by emulsion aggregation comprises:
preparing a emulsion aggregation reaction solution including the coagulant and having a viscosity of equal to or less than about 222 cps.