Sulfur-containing penetrants for ink jet inks

• US 5,169,436 A
• Filed: 05/13/1992
• Issued: 12/08/1992
• Est. Priority Date: 05/13/1992
• Status: Expired due to Term

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Matrick, Howard
• Primary Examiner(s): Beck, Shrive
• Assistant Examiner(s): KLEMANSKI, HELENE G
• Application Number:
  US07/882,400
• Time in Patent Office: 209 Days
• Field of Search: 106/20, 106/22
• US Class Current: 106/31.58
• CPC Class Codes: C09D 11/30 Inkjet printing inks

Abstract

Aqueous ink jet ink compositions comprising an aqueous carrier medium, a colorant and a sulfoxide or sulfone penetrant having a solubility in water of at least 4.5% at 25° C. and represented by the formula:

H(CH.sub.2).sub.a S(O).sub.n (CH.sub.2).sub.b H

wherein

a+b=5-8, and

n=1-2;

exhibit rapid drying, excellent image definition, are storage stable and have excellent decap properties.

Claims

1. An aqueous ink jet ink composition comprising:

(a) an aqueous carrier medium,

(b) a colorant; and

(c) a sulfoxide or sulfone penetrant having a solubility in water of at least 4.5% at 25°

C., and which is represented by the formula;

space="preserve" listing-type="equation">H(CH.sub.2).sub.a S(O).sub.n (CH.sub.2).sub.b H

wherein a+b=5-8, and n=1-2.

2. The ink composition of claim 1 wherein the colorant comprises a pigment and a dispersant.

3. The ink composition of claim 2 wherein the dispersant is a polymeric dispersant.

4. The ink composition of claim 1 wherein a+b=7 and n=1-2.

5. The ink composition of claim 1 wherein a+b=6 and n=1-2.

6. The ink composition of claim 1 wherein n=1.

7. The ink composition of claim 1 wherein n=2.

8. The ink composition of claim 1 wherein the penetrant is di-n-propyl sulfoxide.

9. The ink composition of claim 1 wherein the penetrant is di-n-propyl sulfone.

10. The ink composition of claim 1 wherein the penetrant is ethyl-n-propyl sulfone.

11. The ink composition of claim 1 wherein the penetrant is n-butyl-n-propyl sulfone.

12. The ink composition of claim 2 wherein the pigment comprises particles having a median particle size of approximately 0.01 to 0.3 micron.

13. The ink composition of claim 3 wherein said polymeric dispersant comprises a block copolymer and wherein the ink composition comprises approximately 0.1 to 8% pigment, 0.1 to 8% block copolymer, and 94 to 99.8% aqueous carrier medium plus sulfoxide or sulfone penetrant based upon the total weight of the ink composition.

14. The ink composition of claim 1 wherein the aqueous carrier medium comprises water and at least one water soluble organic solvent.

15. The ink composition of claim 14 wherein the aqueous carrier medium comprises from 30% to 95% water based on the total weight of the aqueous carrier medium plus sulfoxide or sulfone penetrant.

16. The ink composition of claim 1 wherein said colorant is a dye and wherein said ink composition comprises approximately 0.2 to 20% dye, and 80 to 99.8% aqueous carrier medium plus sulfoxide or sulfone penetrant, based on the total weight of the ink composition.

17. The ink composition of claim 1 wherein the aqueous carrier medium is a mixture of water and at least one water soluble organic solvent having at least 2 hydroxyl groups.

18. The ink composition of claim 1 wherein said ink composition has a surface tension of approximately 20 to 70 dyne/cm and a viscosity of no greater than 20 cP at 20°

C.

19. The ink composition of claim 1, wherein a surfactant is present.