Color-bleed resistant silica and silicate pigments and methods of making same
Color-bleed resistant pigment particles containing an anionic dye, a quaternary ammonium compound, and a silica and/or silicate material having a negative zeta potential are disclosed. Related methods of making these colored pigment particles also are provided.
1. Colored pigment particles comprising:
(i) a silica and/or silicate material having a negative zeta potential;
(ii) an anionic dye; and
(iii) a quaternary ammonium compound; wherein:
a ratio of the quaternary ammonium compound to the silica and/or silicate material is in a range from about 50% to 300% of the amount, by weight, of the quaternary ammonium compound sufficient to achieve a zero my zeta potential of a 1 wt. % mixture of the dry silica and/or silicate material in deionized water; and
a weight ratio of the anionic dye is in a range from about 0.02:1 to 0.24:1, based on the weight of the quaternary ammonium compound.
2. The pigment particles of claim 1 , wherein:
the ratio of the quaternary ammonium compound to the silica and/or silicate material is in a range from about 75% to about 175% of the amount, by weight, of the quaternary ammonium compound sufficient to achieve a zero mV zeta potential of a 1 wt. % mixture of the dry silica and/or silicate material in deionized water; and
the weight ratio of the anionic dye is in a range from about 0.04:1 to 0.24:1, based on the weight of the quaternary ammonium compound.
3. The pigment particles of claim 1 , wherein:
the colored pigment particles are characterized by a pH in a range from about 5 to about 9;
the ratio of the quaternary ammonium compound to the silica and/or silicate material is in a range from about 75% to about 200% of the amount, by weight, of the quaternary ammonium compound sufficient to achieve a zero mV zeta potential of a 1 wt. % mixture of the dry silica and/or silicate material in deionized water; and
the weight ratio of the anionic dye is in a range from about 0.02:1 to about 0.18:1, based on the weight of the quaternary ammonium compound.
4. The pigment particles of claim 1 , wherein the colored pigment particles are characterized by:
an average particle size in a range from about 1 μm to about 1000 μm,
a BET surface area in a range from about 1 m 2 /g to about 1200 m 2 /g;
an oil absorption value in a range from about 30 cc/100 g to about 600 cc/100 g;
a pH in a range from about 3 to about 10.5; and
a pack density in a range from about 3 lb/ft 3 to about 60 lb/ft 3 .
5. The pigment particles of claim 1 , wherein the silica and/or silicate material comprises a precipitated silica.
6. The pigment particles of claim 1 , wherein the silica and/or silicate material comprises alkali metal aluminosilicate particles, alkaline earth metal-modified alkali metal aluminosilicate particles, or combinations thereof.
7. The pigment particles of claim 1 , wherein the silica and/or silicate material is characterized by:
an average particle size in a range from about 1 μm to about 1000 μm;
a BET surface area in a range from about 1 m 2 /g to about 1200 m 2 /g;
a pore volume in a range from about 0.5 cc/g to about 6 cc/g;
an oil absorption value in a range from about 30 cc/100 g to about 600 cc/100 g;
a pH in a range from about 3 to about 10.5; and
a zeta potential in a range from about −2 mV to about −70 mV.
8. The pigment particles of claim 1 , wherein the colored pigment particles are substantially free of a binder.
9. The pigment particles of claim 1 , wherein the colored pigment particles are free-flowing.
10. The pigment particles of claim 1 , wherein the anionic dye comprises Red 33, FD&C Red 3, FD&C Red 40, FD&C Blue 1, FD&C Yellow 5, FD&C Yellow 6, FD&C Green 3, or combinations thereof.
11. The pigment particles of claim 1 , wherein the quaternary ammonium compound comprises a polymeric quaternary ammonium compound.
12. The pigment particles of claim 1 , wherein the quaternary ammonium compound comprises a non-polymeric quaternary ammonium compound.
13. The pigment particles of claim 1 , wherein the colored pigment particles exhibit substantially no color bleed in water.
14. The pigment particles of claim 1 , wherein the colored pigment particles are yellow, red, blue, orange, green, or combinations thereof.
15. A composition comprising the pigment particles of claim 1 .
16. The pigment particles of claim 2 , wherein:
the silica and/or silicate material comprises a precipitated silica, and
the quaternary ammonium compound comprises cetylpyridinium chloride (CPC), cetyltrimethylammonium bromide (CTAB), benzalkonium chloride (BAC), or any combination thereof.
17. The pigment particles of claim 16 , wherein:
the colored pigment particles are free-flowing; and
the colored pigment particles exhibit substantially no color bleed in water.
18. The pigment particles of claim 17 , wherein the colored pigment particles are characterized by:
an average particle size in a range from about 1 μm, to about 1000 μm;
a BET surface area in a range from about 1 m 2 /g to about 1200 m 2 /g;
an oil absorption value in a range from about 30 cc/100 g to about 600 cc/100 g;
a pH in a range from about 3 to about 10.5; and
a pack density in a range from about 3 lb/ft 3 to about 60 lb/ft 3 .
19. The pigment particles of claim 3 , wherein:
the silica and/or silicate material comprises a precipitated silica; and
the quaternary ammonium compound comprises cetylpyridinium chloride (CPC), cetyltrimethylammonium bromide (CTAB), benzalkonium chloride (BAC), or any combination thereof.
20. A composition comprising the pigment particles of claim 19 , wherein the colored pigment particles exhibit substantially no color bleed in water.