Stable oil-in-water ink emulsions based upon water-reducible nigrosine dyes for ink-jet printers and felt-tip and roller-ball pens
US5746815A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 31, 1996 |
| Grant date | May 5, 1998 |
| Priority date | — |
| Expiry date | Jul 31, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09D11/328
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A highly fluid water-based ink composition that comprises a stable oil-in-water emulsion of a water-reducible, water-insoluble nigrosine dye-containing solvent solution, preferably containing a high flash-point and high-boiling point solvent, homogeneously dispersed as small, finely divided dye-containing oil droplets in an aqueous carrier solution containing an emulsion stabilizer of a water-soluble resin. Water-insoluble nigrosine dyes are dissolved preferably in relatively low VOC and non-flammable solvent solutions containing non-ionic surfactants to form emulsifiable water-reducible true nigrosine dye-containing solutions. The water-reducible nigrosine dye-containing solutions are then stably emulsified as dye-containing oil droplets in aqueous solutions that contain water, optional solvent diluents, and water-soluble resins that serves as an emulsion stabilizer. The stable oil-in-water ink emulsion is suitable to be ejected through small ink-jet printer nozzles, or through dispensing tips of felt-tip or roller-ball pens, onto a porous substrate, such as paper, to construct a water-fast printed image on the substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.