Acrylate ink compositions for ink-based digital lithographic printing
View Patent ↗An ink composition, including 30% or less pigment, 10% or less dispersant, between 40% and 80% acrylate, 12% or less photoinitiator, and having a viscosity between 2×10 6 cP and 5×10 7 cP at 25° C., and between 2.×10 5 cP and 4.×10 6 cP at 60° C., and a 60 second tack between 40 and 65 g-m at 25° C., and between 10 and 20 g-m at 60° C.
1. An ink composition, comprising:
20% or less by weight pigment, based on a total weight of the ink composition;
10% or less by weight dispersant, based on the total weight of the ink composition;
between 50% and 75% by weight acrylate, based on the total weight of the ink composition, wherein the acrylate comprises propoxylated (6) trimethylolpropane triacrylate, tetra-functional acrylated polyester oligomer and a high-viscosity di-functional acrylated polyester oligomer; and
between 5% and 10% by weight photoinitiator, based on the total weight of the ink composition,
wherein a near-zero shear viscosity of the ink composition is:
between 2×10 6 cP and 5×10 7 cP at 25° C., and
between 2×10 5 cP and 4×10 6 cP at 60° C., and
wherein a 60 second tack of the ink composition is:
between 40 g-m and 65 g-m at 25° C., and
between 10 g-m and 20 g-m at 60° C.
2. The ink composition of claim 1 , further comprising:
1.5% or less by weight stabilizer, based on the total weight of the ink composition; and
12% or less by weight rheology modifier, based on the total weight of the ink composition.
3. The ink composition of claim 2 , comprising:
between 15% and 20% pigment;
between 4% and 8% dispersant;
between 60% and 70% acrylate;
between 5% and 10% photoinitiator;
between 0.1% and 0.3% stabilizer; and
3% or less rheology modifier,
wherein the ink composition has a near-zero shear viscosity between 4×10 6 cP and 1×10 7 cP at 25° C., and between 4×10 5 cP and 8×10 5 cP at 60° C., and
wherein a 60 second tack of the ink composition is between 45 g-m and 55 g-m at 25° C., and between 10 g-m and 15 g-m at 60° C.
4. The ink composition of claim 3 , wherein the acrylate further comprises at least one of an acrylate monomer, acrylate polymer, acrylate oligomer, a difunctional acrylate monomer, and mixtures thereof.
5. The ink composition of claim 1 , wherein the high-viscosity di-functional acrylated polyester oligomer has a viscosity of at least 11,000 cps at 60° C.
6. An ink composition, essentially consisting of:
20% or less by weight pigment, based on a total weight of the ink composition;
10% or less by weight dispersant, based on the total weight of the ink composition;
between 50% and 75% by weight acrylate, based on the total weight of the ink composition,
wherein the acrylate comprises a trifunctional acrylate monomer and a high-viscosity, di-functional acrylated polyester oligomer; and,
optionally, one or more acrylates selected from the group consisting of an acrylate monomer, acrylate polymer, acrylate oligomer, and a difunctional acrylate monomer,
between 5% and 10% by weight photoinitiator, based on the total weight of the ink composition;
1.5% or less by weight stabilizer, based on the total weight of the ink composition;
and 12% or less by weight rheology modifier, based on the total weight of the ink composition,
wherein a near-zero shear viscosity of the ink composition is:
between 2×10 6 cP and 5×10 7 cP at 25° C., and
between 2×10 5 cP and 4×10 6 cP at 60° C.,
and wherein a 60 second tack of the ink composition is:
between 40 g-m and 65 g-m at 25° C., and
between 10 g-m and 20 g-m at 60° C.
7. The ink composition of claim 6 , essentially consisting of:
between 15% and 20% pigment;
between 4% and 8% dispersant;
between 60% and 70% acrylate;
between 5% and 10% photoinitiator;
between 0.1% and 0.3% stabilizer; and
3% or less rheology modifier,
wherein the ink composition has a near-zero shear viscosity between 4×10 6 cP and 1×10 7 cP at 25° C., and between 4×10 5 cP and 8×10 5 cP at 60° C., and
wherein a 60 second tack of the ink composition is between 45 g-m and 55 g-m at 25° C., and between 10 g-m and 15 g-m at 60° C.
8. The ink composition of claim 6 , wherein the high-viscosity di-functional acrylated polyester oligomer has a viscosity of at least 11,000 cps at 60° C.
9. A method of printing using a variable data digital lithographic printing device, comprising:
applying an ink composition to a reimageable surface of an imaging member; and
transferring the ink composition from the reimageable surface to a substrate, wherein the ink composition does not require pre-curing before transferring the ink composition from the reimageable surface to the substrate, wherein the ink composition comprises:
20% or less by weight pigment, based on a total weight of the ink composition;
10% or less by weight dispersant, based on the total weight of the ink composition;
between 50% and 75% by weight acrylate, based on the total weight of the ink composition,
wherein the acrylate comprises a trifunctional acrylate monomer and a high-viscosity, di-functional acrylated polyester oligomer
and optionally one or more acrylates selected from the group consisting of an acrylate monomer, acrylate polymer, acrylate oligomer, and a difunctional acrylate monomer,
between 5% and 10% by weight photoinitiator, based on the total weight of the ink composition;
1.5% or less by weight stabilizer, based on the total weight of the ink composition; and
12% or less by weight rheology modifier, based on the total weight of the ink composition,
wherein a near-zero shear viscosity of the ink composition is:
between 2×10 6 cP and 5×10 7 cP at 25° C., and between 2×10 5 cP and 4×10 6 cP at 60° C.
and wherein a 60 second tack of the ink composition is:
between 40 and 65 g-m at 25° C.,
and between 10 and 20 g-m at 60° C.
10. The method of claim 9 , wherein the ink composition consists essentially of:
between 15% and 20% pigment;
between 4% and 8% dispersant;
between 60% and 70% acrylate;
between 5% and 10% photoinitiator;
between 0.1% and 0.3% stabilizer; and
3% or less rheology modifier;
wherein the ink composition has a near-zero shear viscosity between 4×10 6 cP and 1×10 7 cP at 25° C., and between 4×10 5 cP and 8×10 5 cP at 60° C., and wherein a 60 second tack of the ink composition is between 45 g-m and 55 g-m at 25° C., and between 10 g-m and 15 g-m at 60° C.
11. The method of claim 9 , wherein the high-viscosity di-functional acrylated polyester oligomer has a viscosity of at least 11,000 cps at 60° C.
12. A method of printing using a variable data digital lithographic printing device, comprising:
applying an ink composition at a first temperature to a reimageable surface of an imaging member; and
transferring the ink composition from the reimageable surface to a substrate at a second temperature,
wherein the ink composition does not require pre-curing before transferring the ink composition from the reimageable surface to the substrate,
wherein the ink composition comprises:
20% or less by weight pigment, based on a total weight of the ink composition;
10% or less by weight dispersant, based on the total weight of the ink composition;
between 50% and 75% by weight acrylate, based on the total weight of the ink composition, wherein the acrylate comprises propoxylated (6) trimethylolpropane triacrylate, tetra-functional acrylated polyester oligomer and a high-viscosity di-functional acrylated polyester oligomer; and
between 5% and 10% or less by weight photoinitiator, based on the total weight of the ink composition,
wherein a near-zero shear viscosity of the ink composition is
between 2×10 6 cP and 5×10 7 cP at 25° C., and
between 2×10 5 cP and 4×10 6 cP at 60° C., and
wherein a 60 second tack of the ink composition is
between 40 g-m and 65 g-m at 25° C., and
between 10 g-m and 20 g-m at 60° C.
13. The method of claim 12 , wherein the composition comprises:
between 15% and 20% pigment;
between 4% and 8% dispersant;
between 60% and 70% acrylate;
between 5% and 10% photoinitiator;
between 0.1% and 0.3% stabilizer; and
3% or less rheology modifier,
wherein the ink composition has a near-zero shear viscosity between 4×10 6 cP and 1×10 7 cP at 25° C., and between 4×10 5 cP and 8×10 5 cP at 60° C., and
wherein a 60 second tack of the ink composition is between 45 g-m and 55 g-m at 25° C., and between 10 g-m and 15 g-m at 60° C.
14. The method of claim 13 , wherein the acrylate further comprises at least one of an acrylate monomer, acrylate polymer, acrylate oligomer, a difunctional acrylate monomer, and mixtures thereof.
15. The method of claim 12 , wherein the high-viscosity di-functional acrylated polyester oligomer has a viscosity of at least 11,000 cps at 60° C.