Opaque ink formulations and associated writing instruments

Patent metadata

Field	Value
Publication number	US-12209192-B2
Application number	US-201816755936-A
Country	US
Kind code	B2
Filing date	Oct 25, 2018
Priority date	Oct 26, 2017
Publication date	Jan 28, 2025
Grant date	Jan 28, 2025

Abstract

High opacity permanent ink formulations comprising a solvent, a polymer-based opacifier, a coloring agent, a resin, and a humectant, wherein the ink formulation displays a viscosity of less than about 50 cP, are provided herein.

First claim

What is claimed is:

1. An opaque permanent ink formulation, comprising:
a solvent;
a polymer-based opacifier;
a coloring agent;
a styrene acrylic resin; and
a humectant,
wherein the polymer-based opacifier has a specific gravity between 0.9 g/cc and 1.3 g/cc and is a hybrid between an inorganic pigment and an organic polymer; and
wherein the ink formulation displays a viscosity of less than 50 cP.

2. The ink formulation of claim 1 , wherein the ink formulation displays a viscosity of less than 20 cP.

3. The ink formulation of claim 1 , wherein the ink formulation displays a viscosity of less than 10 cP.

4. The ink formulation of claim 1 , wherein the resin shows a solubility of at least 5% by weight in the solvent and possesses both polar and non-polar domains.

5. The ink formulation of claim 1 , wherein the resin is a water-based resin.

6. The ink formulation of claim 1 , wherein the solvent and resin are selected such that the solvent is capable of dissolving the resin.

7. The ink formulation of claim 1 , wherein the solvent is protic polar or aprotic polar.

8. The ink formulation of claim 1 , wherein the solvent is selected from water, alcohols, ethers, and acetone.

9. The ink formulation of claim 1 , wherein the coloring agent is a dye or pigment.

10. The ink formulation of claim 9 , wherein the coloring agent is a pigment provided in the form of a dispersion in a solvent prior to addition to the formulation.

11. The ink formulation of claim 9 , wherein the coloring agent is a dye capable of adhering to a surface of the polymer-based opacifier particles.

12. The ink formulation of claim 1 , wherein the humectant is selected from simple polyols, oligomeric and polymeric polyols, polyethylene glycol, polypropylene glycol, and poly (tetramethylene ether) glycol.

13. The ink formulation of claim 1 , further comprising one or more additives selected from dispersants, surfactants, co-solvents, rheological additives, biocides, and water-based optical brighteners.

14. The ink formulation of claim 1 , wherein the ink formulation is substantially opaque when disposed at a film thickness of 20 microns or less.

15. An opaque permanent ink formulation, comprising:
a solvent comprising water;
a polymer-based opacifier;
a coloring agent;
a permanent ink resin; and
a humectant,
wherein the polymer-based opacifier has a specific gravity between 0.9 g/cc and 1.3 g/cc and is a hybrid between an inorganic pigment and an organic polymer;
wherein the ink formulation displays a viscosity of less than 50 cP; and
wherein the permanent ink resin is a styrene acrylic resin.

16. A writing instrument comprising the ink formulation of claim 15 .

17. The writing instrument of claim 16 , further comprising:
a reservoir containing the ink formulation; and
a nib in fluid communication with the reservoir, the nib being configured to deliver the ink formulation from the writing instrument.

18. The ink formulation of claim 15 , wherein the ink formulation displays a viscosity of less than 20 cP.

19. The ink formulation of claim 15 , wherein the ink formulation displays a viscosity of less than 10 cP.

Assignees

• Sanford Lp

Inventors

• Kwan Wing Sum Vincent
• Sexton Marty

Classifications

• C09D11/20

  indelible · CPC title

• C08L101/00

  Compositions of unspecified macromolecular compounds · CPC title

• C08K5/0041

  Optical brightening agents, organic pigments · CPC title

• B43K7/02

  Ink reservoirs; Ink cartridges (B43K7/01 takes precedence) · CPC title

• B43K7/01

  for low viscosity liquid ink · CPC title