Yellow pigment dispersion
AssigneeE. I. Du Pont de Nemours and Company
InventorsChristian Jackson, Robert Paul Held, C. Chad Roberts, Nathaniel Reed Schwartz, Gregory R. Schulz
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Abstract
This invention pertains to an aqueous based dispersion of Pigment Yellow 74 which uses a certain class of polymeric dispersants which dispersant is particularly effective at dispersing the pigment and preventing pigment particle growth on storage. The classes of polymeric dispersants are based on random copolymers of an ionic momomer and a hydrophobic monomer chosen from benzyl(meth)acrylate or alkyl(meth)acrylate where the alkyl group has four to ten carbon atoms and (meth)acrylic acid. The invention also pertains to an inkjet ink comprising this Pigment Yellow 74 dispersion.
Claims14
A yellow pigment dispersion composition comprising an aqueous vehicle and Pigment Yellow 74 stabilized by a dispersant polymer absorbed onto the surface of the Pigment Yellow 74, said dispersant polymer is a random polymer comprising at least
- a. a first monomer which is an ionic monomer;
- b. a second monomer which is a hydrophobic monomer and wherein the hydrophobic monomer is selected from the group consisting of benzyl(meth)acrylate, substituted benzyl(meth)acrylate and linear, branched and cyclic alkyl(meth)acrylate where the alkyl has four to ten carbons;
- c. the hydrophobic monomer is at least 65 weight % of the polymeric dispersant,
- d. the random polymer has a number average molecular weight (Mn) from 6000 to 20,000;
- and
- e. the random polymer has an acid number of from 80 to 200.
Dependencies are inferred from the claim text.