IMPROVED INK JET INK COMPOSITIONS
Original Publication Date: 1995-Apr-30
Included in the Prior Art Database: 2004-Apr-07
Xerox Disclosure Journal
Marcel P. Breton John F. Oliver Int. C1. G03g 15/10 Raymond W. Wong Gary R Fague Geoffrey A. Nobes Ken Woodcock Carol Ann Jennings Lesley P. Dudek W. Conrad Richards Richard L. Colt William M. Schwarz Kurt B. Gundlach
XEROX DISCLOSURE JOURNAL
IMPROVED INK JET INK COMPOSITIONS U.S. C1,355/256 Marcel P. Breton John F. Oliver Int. C1. G03g 15/10 Raymond W. Wong Gary R Fague
Geoffrey A. Nobes Ken Woodcock
Carol Ann Jennings Lesley P. Dudek
W. Conrad Richards Richard L. Colt William M. Schwarz Kurt B. Gundlach
Disclosed are fast drying ink jet inks with improved latency, maintainability, recoverability, and excellent print quality on plain paper. The inks have latencies at about 15% relative humidity in the range of about 100 to about 10,000 seconds. The inks are optimized with respect to the dye and cosolvent combination based on their respective solubility parameters. Preferably, the cosolvents have a low viscosity. The dye has a high solubility in the ink. The dye has good solubility in water. At least one of the cosolvents selected is a very good penetrant, and is used in an amount suitable for reducing the surface tension of the ink to from 30 and 40 dynes per centimeter, and preferably between about 33 and 38 dynes per centimeter. The improved inks are comprised of water, butyl carbitol, and one or more of the following cosolvents: cyclohexylpyrolidinone, glycerol, 2-pyrrolidinone, diethylene glycol, ethylene glycol, and sulfolane. The drying times of the inks are less than 1 second at greater than about 80% relative humidity on plain papers. Suitable dyes for use in the improved inks include: Pro-jet Black 1 (Direct Black 168), Food Black 2, Pro-jet Cyan 1 (Direct Blue 199), Pro-jet Yellow 1G (Direct Yellow 132), and Mitsubishi Magenta MKJR-064-1. The improved ink compositions possess a latency greater than about 100 seconds at 15% relative humidity. The improved inks possess minimum intercolor bleeding on plain papers.
In an alternative embodiment, the improved inks may contain a standard ink
, et dye, sulfolane, butyl carbitol, polyethylene oxide, and water in addition to an ionic salt which enables the inks to absorb microwave energy more efficiently and thus allow for assisted drying of printed images. A suitable ionic salt is, for example, ammonium bromide. Latency is defined as the length of time that a printhead can settle, without firing a drop, and upon firing once again produce a drop with a velocity of greater than 5 meters per second. In the context of a Full-width array thermal ink jet device, two types of latency are relevant: PERF latency wherein a single jet is used; and a GRAPE text fixture wherein a full-width array at 600 spi is used.
Thermal Ink Jet (TIJ) inks containing ammonium bromide as the ionic salt were formulated and evaluated according to a base formulation: 3.0 to 5.0% by weight of a water soluble ink jet dye (i.e. Direct Black 168 or Basacid Black X-
34), 14.2 to 28.3% by weight tetramethylene sulfone (sulfolane), 5.8 to 11.7% by weight butyl carbitol, 2.0 to 4.0% by weight ammonium bromide, 0.03 to
0.10% by weight polyethylene oxide 18,500 and deionized water to 100%. The total amount of...