Pigment dispersant
Inventors
Samanta, Shampa R. • Patel, Chintankumar • Wade, Colin • Mohr, Benjamin Georg Robert
Assignees
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Publication Number
US-11859106-B2
Publication Date
2024-01-02
Expiration Date
Abstract
Described herein is a polymeric pigment dispersant, a process for preparation of the polymeric pigment dispersant, and a pigment dispersion including the pigment dispersant that is used for coating and in printing ink, automotive basecoat, automotive clearcoat, mill base, furniture coatings, and wood coatings.
Core Innovation
The invention relates to a polymeric pigment dispersant comprising a polymer backbone (P) bearing at least one moiety of a formula (I), wherein R1 is selected from naphthyl, anthracenyl and phenanthrenyl, and the at least one moiety of formula (I) is bonded to the polymer backbone (P) via the —C(O)O— linkage. The invention addresses sub-100 nm pigment agglomeration and proposes improved anchoring and colloidal stabilization by interactions associated with the moiety of formula (I), including π–π interaction and hydrogen-bonding interaction, to enable strong adsorption to pigment surfaces and improved dispersion behavior for pigments having particle size <100 nm.
The disclosed pigment dispersant is extended to pigment dispersions and coating/ink uses, including printing inks and coating compositions such as automotive basecoat/clearcoat, mill base, furniture coatings, and wood coatings. The claimed improvement includes increased solubility in low-polarity solvents for easier/cost-effective synthesis, steric stabilization originating from the polymer backbone (P), and reduced reaction with strong acid catalysts, while maintaining improved color characteristics described via reduced coating lightness L*.
Claims Coverage
The independent claims cover two inventive features: the polymeric pigment dispersant structure and a process for preparing the polymeric pigment dispersant. The claim set centers on a specific formula (I) moiety linked to a polymer backbone (P) through a —C(O)—O— bond, and on reacting a linear di-block polymer with a compound of formula (IV).
Polymeric pigment dispersant with formula (I) moiety linked via —C(O)—O—
A polymeric pigment dispersant comprising a polymer backbone (P) and at least one moiety of a formula (I), wherein R1 is selected from unsubstituted or substituted naphthyl, anthracenyl and phenanthrenyl, and the at least one moiety of formula (I) is bonded to the polymer backbone (P) via the —C(O)—O— group.
Process by reacting linear di-block polymer with formula (IV) compound
A process for preparing at least one polymeric pigment dispersant by reacting a linear di-block polymer with a compound of formula (IV), with the linear di-block polymer comprising a first and a second block and being obtained by living free radical polymerization.
Across the independent claims, protection is centered on a formula (I) moiety bonded to a polymer backbone (P) through a —C(O)—O— linkage, and on preparing that dispersant by reacting a living free radical-derived linear di-block polymer with a formula (IV) compound.
Stated Advantages
Enhanced dispersion of submicron pigments, including pigments with particle size <100 nm.
Improved chroma/transparent color, described via reduced coating lightness L*.
Strong adsorption to pigment surfaces.
Increased solubility in low-polarity solvents for easier/cost-effective synthesis.
Steric stabilization provided by the polymer backbone (P).
Reduced reaction with strong acid catalysts.
Documented Applications
Pigment dispersions comprising a polymeric pigment dispersant, a solvent, and a pigment.
Printing inks.
Automotive basecoat and automotive clearcoat.
Mill base.
Furniture coatings.
Wood coatings.
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