Aqueous ink compositions containing anti-curl agents

Claim 2

The ink composition of claim 1, wherein the anti-curl agent has a solubility in water at least 4.5% at 25° C and is selected from the group consisting of: (a) 1,3-diols, 1,3,5-triols, amino-1,3-diols and polyoxyalkylene derivatives thereof having the following structure: wherein R₁, R₂, R₄, R₅ and R₆ are independently H; C n H 2n+1 , where n = 1-4; or C n H 2n O(CH₂CHYO) b H where n = 1-6 and b = 0-25; R₃ = H; C n H 2n+1 where n = 1-4; C n H 2n O(CH₂CHYO) b H where n = 1-6 and b = 0-25; or (CH₂) e NXZ, where X and Z are independently H, CH₃, C₂H₅ or C₂H₄O(CH₂CHYO) d H, where d = 0-25 and e = 0-3; Y = H or CH₃; a and c are independently 0-25; and wherein the total number of CH₂CHYO units is 0-100; (b) polyols and oxyalkylene derivatives thereof having the following structure: wherein R is independently H, C n H₂₊₁, where n = 0-4, or CH₂O(CH₂CHYO) e H; Y = H or CH₃, b = 0 or 1; a, c, d and e are independently 0-40, f = 1-6; and wherein the total number of CH₂CHYO units is 0-100; with the proviso that when a, b, c and d = 0, and f = 1, R is not H and when a, c, and d = 0 and b and f = 1, e is not 0; (c) compounds having the following structure: wherein X = H; OH; CH₂O(CH₂CHYO) a H; O(CH₂CHYO) b H; or OM where M is a metal cation; n = 2-7; R = (CH₂CHYO) c , where Y = H or CH₃; a, b and c are independently 0-25; and wherein the total number of CH₂CHYO units is 0-125; (d) pyranosides and polyalkoxyalkylene derivatives thereof having the following structure: wherein R = H or C n H₂₊₁, where n = 0-4; a, b, c and d are independently 0-30; Y = H or CH₃; and wherein the total number of CH₂CHYO units is 0-120; (e) poly(oxyalkylene) compounds having the following structure: H-(OCH₂CHY) x OH wherein Y = H or CH₃, and x = 3-20; and (f) polyoxyalkylene derivatives of aliphatic polyamines having the structure: Z₁Z₂N(CH₂CH₂NZ₃) n Z₄ wherein Z₁, Z₂, Z₃, or Z₄ are independently (CH₂CHYO) a H  where Y = H or CH₃; n = 1-20; a is independently 0-20; and wherein the total number of CH₂CHYO units is 3-200.

Claim 3

The ink composition of claim 2, wherein the colorant is a pigment dispersion comprising a pigment and a polymeric dispersant.

Claim 4

The ink composition of claim 2, wherein the colorant is a dye.

Claim 5

The ink composition of claim 2, wherein the anti-curl agent is a compound having structure (a).

Claim 6

The ink composition of claim 5, wherein R₃ and R₄ are independently selected from the group consisting of H and C n H 2n+1 , where n = 1-4.

Claim 7

The ink composition of claim 5, wherein the anti-curl agent is 2,2-dimethyl-1,3-propanediol.

Claim 8

The ink composition of claim 5, wherein R₃ is NXZ, wherein X is selected from the group consisting of H, CH₃, C₂H₅ and C₂H₄OH.

Claim 9

The ink composition of claim 5, wherein the total number of CH₂CHYO units = 2-50.

Claim 10

The ink composition of claim 5, wherein the anti-curl agent is 3-methyl-1,3,5-pentanetriol.

Claim 11

The ink composition of claim 2, wherein the anti-curl agent is a compound having structure (b).

Claim 12

The ink composition of claim 11, wherein the total number of CH₂CHYO units = 3-50.

Claim 13

The ink composition of claim 11, wherein the anti-curl agent is 2-ethyl-2-(hydroxymethyl)-1,3-propanediol.

Claim 14

The ink composition of claim 11, wherein the anti-curl agent is 2-methyl-2-(hydroxymethyl)-1,3-propanediol.

Claim 15

The ink composition of claim 11, wherein the anti-curl agent is sorbitol.

Claim 16

The ink composition of claim 2, wherein the anti-curl agent is a compound having structure (c).

Claim 17

The ink composition of claim 16, wherein the anti-curl agent is alpha-D-glucose.

Claim 18

The ink composition of claim 2, wherein the anti-curl agent is a compound having structure (d).

Claim 19

The ink composition of claim 18, wherein the anti-curl agent is an oxyalkylene derivative of methyl alpha-D-glucoside.

Claim 20

The ink composition of claim 2, wherein the anti-curl agent is a compound having structure (e).

Claim 21

The ink composition of claim 20, wherein the anti-curl agent is selected from the group consisting of triethylene glycol, tetraethylene glycol and polyethylene glycol having a molecular weight in the range of 200-400.

Claim 22

The ink composition of claim 2, wherein the anti-curl agent is a compound having structure (f).

Claim 23

The ink composition of claim 22, wherein the anti-curl agent is a polyoxyethylene derivative of ethylenediamine.

Claim 24

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 84 to 99.8% aqueous carrier medium taken together with the weight of the anti-curl agent, based upon the total weight of the ink composition.

Claim 25

The ink composition of claim 4, comprising approximately 0.01 to 20% dye, and 80 to 99.99% aqueous carrier medium taken together with the weight of the anti-curl agent, based on the total weight of the ink composition.

Claim 26

The ink composition of claim 4, further comprising a polymer selected from the group consisting of AB block polymers, BAB block polymers, ABC block polymers and random polymers.

Claim 27

The ink composition of claim 4, wherein said ink is part of an aqueous dye-based ink set for ink jet printers having improved color gamut, said ink set comprising a cyan ink, a magenta ink and a yellow ink, and wherein each of said inks comprises an anti-curl agent.

Claim 28

The ink composition of claim 27, wherein the cyan ink comprises 1.75 to 2.5% of Acid Blue 9 dye, the yellow ink comprises 1.75 to 3% of Acid Yellow 23 dye, and the magenta ink comprises 1 to 3% of Reactive Red 180 dye and 0.3 to 1.5 % of Acid Red 52 dye.

Claim 29

The ink composition of claim 1, wherein the anti-curl agent is present in the amount of 10-75% by weight, based on the total weight of ink.

Claim 30

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

Claim 31

The ink composition of claim 1, further comprising a surfactant.

Claim 32

A process for reducing paper curl in plain-paper printed elements, consisting essentially of the step of applying an ink composition to a plain-paper substrate, wherein said ink composition comprises an aqueous carrier medium, a colorant and at least one anti-curl agent in an amount sufficient to substantially eliminate curl in said plain-paper substrate.

Claim 33

The process of claim 32, wherein the anti-curl agent has a solubility in water of at least 4.5% at 25° C and is selected from the group consisting of: (a) 1,3-diols, 1,3,5-triols, amino-1,3-diols and polyoxyalkylene derivatives thereof having the following structure: wherein R₁, R₂, R₄, R₅ and R₆ are independently H; C n H 2n+1 , where n = 1-4; or C n H 2n O(CH₂CHYO) b H where n = 1-6 and b = 0-25; R₃ = H; C n H 2n+1 where n = 1-4; C n H 2n O(CH₂CHYO) b H where n = 1-6 and b = 0-25; or (CH₂) e NXZ, where X and Z are independently H, CH₃, C₂H₅ or C₂H₄O(CH₂CHYO) d H, where d = 0-25 and e = 0-3; Y = H or CH₃; a and c are independently 0-25; and wherein the total number of CH₂CHYO units is 0-100; (b) polyols and oxyalkylene derivatives thereof having the following structure: wherein R is independently H, C n H₂₊₁, where n = 0-4, or CH₂O(CH₂CHYO) e H; Y = H or CH₃, b = 0 or 1; a, c, d and e are independently 0-40, f = 1-6; and wherein the total number of CH₂CHYO units is 0-100; with the proviso that when a, b, c and d = 0, and f = 1, R is not H and when a, c, and d = 0 and b and f = 1, e is not 0; (c) compounds having the following structure: wherein X = H; OH; CH₂O(CH₂CHYO) a H; O(CH₂CHYO) b H; or OM where M is a metal cation; n = 2-7; R = (CH₂CHYO) c , where Y = H or CH₃; a, b and c are independently 0-25; and wherein the total number of CH₂CHYO units is 0-125; (d) pyranosides and polyalkoxyalkylene derivatives thereof having the following structure: wherein R = H or C n H₂₊₁, where n = 0-4; a, b, c and d are independently 0-30; Y = H or CH₃; and wherein the total number of CH₂CHYO units is 0-120; (e) poly(oxyalkylene) compounds having the following structure: H-(OCH₂CHY) x OH wherein Y = H or CH₃, and x = 3-20; and (f) polyoxyalkylene derivatives of aliphatic polyamines having the structure: Z₁Z₂N(CH₂CH₂NZ₃) n Z₄ wherein Z₁, Z₂, Z₃, or Z₄ are independently (CH₂CHYO) a H where Y = H or CH₃; n = 1-20; a is independently 0-20; and wherein the total number of CH₂CHYO units is 3-200.

Claim 34

The process of claim 33, wherein the anti-curl agent is a compound having structure (a).

Claim 35

The process of claim 33, wherein the anti-curl agent is a compound having structure (b).

Claim 36

The process of claim 33, wherein the anti-curl agent is a compound having structure (c).

Claim 37

The process of claim 33, wherein the anti-curl agent is a compound having structure (d).

Claim 38

The process of claim 33, wherein the anti-curl agent is a compound having structure (e).

Claim 39

The process of claim 33, wherein the anti-curl agent is a compound having structure (f).

Claim 40

The process of claim 33, wherein said colorant comprises a pigment and a polymeric dispersant.

Claim 41

The process of claim 33, wherein the colorant comprises a dye.

Claim 42

The process of claim 41, wherein said ink composition further comprises a polymer selected from the group consisting of AB block polymers, BAB block polymers, ABC block polymers and random polymers.

Claim 43

The process of claim 33, wherein said ink composition comprises an ink jet ink and wherein said step of applying said ink to a substrate comprises applying said ink with an ink jet printer.