INK COMPOSITION COMPRISING CATIONIC, WATER-SOLUBLE RESIN

• US 20010018471A1
• Filed: 03/25/1998
• Published: 08/30/2001
• Est. Priority Date: 03/25/1997
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: TANIGUCHI, MAKOTO, OHTA, HITOSHI, KITAMURA, KAZUHIKO
• Granted Patent: US 6,720,367 B2
• Time in Patent Office: Days
• US Class Current: 523/160
• CPC Class Codes: C09D 11/30 Inkjet printing inks
• CPC Class Codes: C09D 11/40 Ink-sets specially adapted for multi-colour inkjet printing

Abstract

A composition, for ink jet recording, containing a cationic, water-soluble resin comprising a repeating unit represented by the following formula (I) can realize an image possessing excellent waterproofness and lightfastness and having no significant feathering or bleeding, especially no significant color-to-color bleeding:

wherein R¹ and R² which may be the same or different represent a hydrogen atom or a C_1-5 alkyl group, provided that R¹ and R² do not simultaneously represent a hydrogen atom; and n is 0, 1, or 2.

Claims

1. An ink composition comprising an alkali-soluble colorant, a water-soluble organic solvent, water, and a cationic, water-soluble resin,

the cationic, water-soluble resin comprising a repeating unit represented by the following formula (I):

wherein R¹ and R² which may be the same or different represent a hydrogen atom or a C_1-5 alkyl group, provided that R¹ and R² do not simultaneously represent a hydrogen atom; and

n is 0, 1, or 2.

2. The ink composition according to

claim 1

, wherein the cationic, water-soluble resin has an average molecular weight of 300 to 10,000.

3. The ink composition according to

claim 1

or

2

, wherein the cationic, water-soluble resin is an acid addition salt.

4. The ink composition according to any one of

claims 1

to

3

, which further comprises a base.

5. The ink composition according to any one of

claims 1

to

4

, wherein the base is a hydroxide of an alkali metal or an alkaline earth metal.

6. The ink composition according to any one of

claims 1

to

5

, wherein both R₁ and R₂ in the repeating unit represented by the formula (I) represent a methyl group.

7. The ink composition according to any one of

claims 1

to

6

, wherein n is 1.

8. The ink composition according to any one of

claims 1

to

7

, wherein the water-soluble organic solvent has a lower vapor pressure-than water.

9. The ink composition according to any one of

claims 1

to

8

, wherein the water-soluble organic solvent is contained in an amount of 5 to 50% by weight based on the total amount of the ink.

10. The ink composition according to any one of

claims 1

to

9

, wherein the colorant is a dye or a pigment.

11. The ink composition according to any one of

claims 1

to

10

, which further comprises a water-soluble resin other than the cationic, water-soluble resin.

12. An ink set comprising a black ink, a yellow ink, a cyan ink, and a magenta ink, said black, yellow, cyan, and magenta inks each independently being the ink composition according to any one of

claims 1

to

11

,

the black ink comprising a colorant selected from a group of dyes consisting of C.I. Direct Black 19, 35, 154, 168, 171, and 195 and C.I. Food Black 2,

the yellow ink comprising a colorant selected from a group of dyes consisting of C.I. Direct Yellow 50, 55, 86, 132, 142, and 144 and C.I. Acid Yellow 23.

the cyan ink comprising a colorant selected from a group of dyes consisting of C.I. Direct Blue 86, 87, and 199 and C.I. Acid Blue 9 and 249,

the magenta ink comprising a colorant selected from a group of dyes consisting of C.I. Direct Red 9 and 227, C.I. Acid Red 52 and 289, and dyes represented by the following structural formula (TI):

wherein R³ and R⁴ represent a hydrogen atom, a C_1-5 alkyl group, an aryl group, a C_1-5 alkoxy group, or a phenoxy group or a derivative thereof, a triazine ring or a derivative thereof, a carboxyl group or a salt thereof, or a sulfonyl group or a derivative thereof;

X represents a hydrogen or halogen atom; and

Y¹ and Y² which may be the same or different represent an alkali metal atom, ammonium, or a C_1-5 alkylammonium.

13. An ink set comprising a first ink composition or a group of first ink compositions and a second ink composition or a group of second ink compositions,

the first ink composition being the ink composition according to any one of

claims 1

to

11

,

the second ink composition being an ink composition comprising an anionic material.

14. The ink set according to

claim 13

, wherein the group of first ink compositions comprises a yellow ink, a magenta ink, and a cyan ink and

the second ink composition is a black ink.

15. The ink set according to

claim 13

, wherein

the first ink composition is a black ink and

the second group of ink compositions comprises a yellow ink, a magenta ink, and a cyan ink.

16. The ink set according to any one of

claims 13

to

15

, wherein the anionic material contained in the second ink composition is an anionic, water-soluble resin.

17. The ink set according-to any one of claims 16, wherein the colorant contained in the second ink composition is a pigment.

18. The ink set according to any one of

claims 13

to

15

, wherein the anionic material in the second ink composition is a pigment having an anionic functional group on its surface.

19. A recording method comprising the step of:

depositing an ink composition onto a recording medium to form an image on the recording medium,

wherein the ink composition according to any one of

claims 1

to

11

or the ink composition in the ink set according to any one of

claims 12

to

18

is used as the ink composition.

20. An ink jet recording method comprising the step of:

ejecting and depositing droplets of an ink composition onto a recording medium to form an image on the recording medium,

wherein the ink composition according to any one of

claims 1

to

11

or the ink composition in the ink set according to any one of

claims 12

to

18

is used as the ink composition.

21. A recorded medium obtained by the method according to

claim 19

or

20

.