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US 6,632,858 B1Granted
Colored polyurethanes
AssigneeAvecia Limited
InventorsDavid Alan Pears, John Christopher Padget, Mark Robert James, Peter Gregory
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Abstract
The invention relates to polyurethanes, inks comprising polyurethanes and their use in ink jet printing where the polyurethane comprises a colored water-dissipatable polyurethane obtainable from the reaction of a polyisocyanate, a compound providing water-dispersing groups and a colorant having at least two functional groups.
Claims9
An ink having a viscosity of less than 20 cp at 20° C. comprising
- (a) a non-isocyanate terminated, coloured, water-dissipatable polyurethane, having a weight average molecular weight from 1,000 to 15,000 obtained from the reaction of a mixture comprising the components:
- (i) at least one organic polyisocyanate;
- (ii) at least one isocyanate-reactive compound providing ionic water-dispersing groups provided that the isocyanate-reactive compound providing ionic water-dispersing groups excludes polyesters bearing sulphonic acid groups;
- and
- (iii) at least one colorant having at least two functional groups selected from isocyanate groups and isocyanate-reactive groups;
- where the proportion of insoluble polyurethane in water is less than 50%;
- provided that the polyurethane is not a chain-extended polyurethane and
- (b) a liquid medium.
5 more elements
Dependencies are inferred from the claim text.