Pigment Patents

I do all ‘that stuff,’ for the same reason you don’t.

We are on all the time; some onliners have little other life. Learning from them is following apt to lead you to a parking lot at the back lot of their career. Beware is the advice. Beware things like “it can’t be pigments cause they won’t fit through those nozzles. “(from the purchasing agent from the Pela Store)

Just like germs didn’t exist: cause nothing that small can hurt you.

Reading patents isn’t an idling for me. I do it to know more than I did; an easy way of following people with degrees, not just degrees of opinion. Some patents are instructional – these patents contain much more foundation information than typical. They seem written as a farewell address; written at a apex of the industry, the company, even the researcher.

I seek patents written by the major companies involved in photography: Kodak, Fuji, Epson, etc.

In the following, note the definition of “pigment,” and “dye.” These are the current uses of the words in colorant chemistry.

“The inks used in the various inkjet printers can be classified as either pigment-based or dye-based. A pigment is a colorant that is insoluble in the carrier medium, but is dispersed or Suspended in the form of Small particles, often Stabilized against flocculation and Settling by the use of dispersing agents. A dye is a colorant that is molecularly dispersed or dissolved in the carrier medium. In either case, the carrier medium can be a liquid or a Solid at room temperature. Commonly used carrier media are acqueous based and include water as the major constituent, water miscible humectants, water-miscible organic co-Solvents and Surfactants.”US 2005/0139122 A1
— gamut increase 1997 Kodak
The invention provides a pigment set comprising a magenta pigment, a yellow pigment, and a cyan pigment wherein the normalized spectral transmission density distribution curve of the cyan pigment has a density between 0.66 so and 0.94 at 600nm and a density between 0.83 and 1 .0 at 610nm, and the magenta pigment has a density between 0.25 and 0.93 at 520nm, a density between 0.9 and 1 .0 at 540nm, and a density between 0.9 and 1 .0 at 560nm. The invention further includes an imaging system containing such pigment set and a method of imaging there with. EP0831132A2
Which was a long time ago in a growing technology; 25 years. The specifics are still useful as guidance to current readers.

Small pigments have been around for decades (the 90s). There are at least two significant methods of making small pigments. One uses filtration and dispersion to get same size particles. The other uses compression, grinding then filtration dispersion. This method assure shape and size of pigments.

U.S. Pat. No. 5,679,138 describes preparation of nanoparticulate dispersions and inks

U.S. Pat. No. 6,494,943 B1 describes inkjet inks containing colored pigments having one or more desired parameters including a filterability Such that when in a liquid medium, 100 mL having 10% solids of the colored

US 5990197 ESCANO
US 0121093 OGINO
US 0003112 DEMEJO

Pigment inks prepared with mean pigment particle sizes in the preferred range of 0.100 microns
or less, fired continuously, and reliably for longer periods of
time and contributed to longer printhead lifetimes. 2005