Ink compositions

Abstract

A process for the preparation of an ink which comprises mixing an ink vehicle, a colorant and a polyurethane resin emulsion.

Description

PENDING APPLICATIONS AND PATENTSDisclosed in U.S. Pat. No. 5,837,043 and U.S. Pat. No. 5,762,695 the disclosures of each patent being totally incorporated herein by reference in their entirety, are inks with certain surfactants. More specifically, in U.S. Pat. No. 5,762,695, there is disclosed an ink jet ink and imaging process which comprises the development of an image with an aqueous ink jet ink composition comprised of colorant, water, and a polyhydroxy alcohol surfactant present in an amount of from about 2 to about 10 weight percent.The following patents, the disclosures of each being totally incorporated herein by reference relate to ink jet inks:U.S. Pat. No. 5,973,026 relating to an aqueous ink containing a dissipatible polymer, colorant and a zwitterionic component like betaine;U.S. Pat. No. 5,977,209 relating to an ink containing a colorant, polymer, such as a dissipatible polymer, vehicle, and a salt of polyacrylic, a salt of polyamic acid, a salt of alginic acid, or mix...

AI Technical Summary

Benefits of technology

The inks of the present invention possess excellent dry and wet smear resistance, that is a dry smear optical density of at least less than about 0.10, more generally a dry smear optical density of preferably from about 0 to about 0.07. (the less OD values for smear indicate less transfer onto people). The OD smear is a measure of how much ink or developed image can be removed from the original image as compared with a print image of the same ink without the polyurethane resin. The wet smear optical density of the inks is at least about 0.20, and more generally the wet smear optical density is about 0.10, and preferably from about 0 to about 0.10. The advantage to reduction in smear is that the productivity of the output of prints can be increased, when the smear is reduced. If reduced, the page to page contact is unaffected by smeared images on the backside of pages. Also, less of the image would be transferred to people's fingers etc. Another advantage, is possibly for highlighter smearing. Less smear would enable less transfer when a highlighter pen is drawn across the image, or when liquids are spilled and wiped up.

Problems solved by technology

As the bubble begins to collapse, the ink remaining in the channel between the nozzle and bubble starts to move toward the collapsing bubble, causing a volumetric contraction of the ink at the nozzle and resulting in the separation from the nozzle of the bulging ink as a droplet.

Dye-based ink jet inks suffer from deficiencies in waterfastness and lightfastness after being printed on various substrates.

Some cosolvents that can be selected as clogging inhibitors cause destabilization of pigment dispersions and, therefore, are not usually effective in pigmented inks.