| 摘要 |
Densified carbon black colouring material readily dispersible in water comprises a major proportion of carbon black and at least 1 per cent. by weight of finely divided bentonite intimately dispersed in said carbon black. The densified carbon black has a bulk density of more than about 18 pounds per cubic foot and may be produced by tumbling or pressing under a high load and may be in the form of beads or pellets or crushed granules. The particles of bentonite may be predominantly smaller than 300 mesh (Tyler standard).ALSO:A composition readily dispersible in water for use in water-based paints and inks and for colouring paper comprises a major proportion of carbon black and at least one per cent, preferably about 25 per cent, by weight of finely divided bentonite. The particles of bentonite may be predominantly smaller than 300 mesh (Tyler standard). The bentonite, while essentially montmorillonite, may contain appreciable quantities of calcium and magnesium. Bentonites specified are Wyoming bentonite and materials available under the trade names Aquagel, BC Volclay, National Standard, Magcogel and Control gel. The composition is in the form of bead or pellets or crushed granules produced by tumbling or pressing and has a bulk density of about 18 pounds per cubic foot or more. |
