Ink set for ink-jet recording, process for producing same, method of image recording, and print
AssigneeSeiko Epson Corporation
InventorToshiyuki Miyabayashi
Life of this patent
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Abstract
The present invention relates to an ink jet recording ink set comprising a plurality of ink compositions each containing at least a colorant, a water-soluble organic solvent and water; and to a preparation process thereof. The invention is characterized by that the flowing characteristics or dynamic viscoelasticity at 20° C. of each of said plurality of ink compositions are set to satisfy specific conditions. The present invention also relates to an image recording method and recorded matter having an image formed thereon, each of the image being formed using the above-described ink jet recording ink set or an ink jet recording ink set prepared by the above-described process.
Claims51
An ink jet recording ink set comprising a plurality of ink compositions each containing at least a colorant, a water-soluble organic solvent and water, wherein among said plurality of ink compositions, a difference in zero shear viscosity which is a value at sin θ=0 (θ=0) is 0.2 mPa·s or less and a difference in the slope of a sin θ vs. viscosity curve is within 0.04, said sin θ vs. viscosity curve being obtained by carrying out rolling-ball system measurement of the viscosity of each of the ink compositions under the temperature condition of 20° C. while changing an inclination angle θ to predetermined angles, determining the viscosity at the predetermined angles, and plotting the sin θ and the viscosity along the abscissa and the ordinate, respectively.
An inkjet recording ink set comprising a plurality of ink compositions each containing at least a colorant, a water-soluble organic solvent and water, wherein each of said plurality of ink compositions has flowing characteristics at 20° C. set to satisfy the following expression (I):
- 0.6 ≤ log σ γ = 5 · - log σ γ = 3 · log 5 - log 3 ( I )
- wherein
- σγ=3:
- shear stress (Pa) when the shear rate of the ink is 3 (sec−1), and
- σγ=5:
- shear stress (Pa) when the shear rate of the ink is 5 (sec−1).
An ink jet recording ink set comprising a plurality of ink compositions each containing at least a colorant, a water-soluble organic solvent and water, wherein each of said plurality of ink compositions having flowing characteristics at 20° C. set to satisfy the below-described expression (IV):
- 0.6 ≤ log σ γ = 4 × 10 4 · - log σ γ = 3 × 10 4 · log ( 4 × 10 4 ) - log ( 3 × 10 4 ) ≤ 1 ( IV )
- wherein
- σγ=3×104:
- shear stress (Pa) when the shear rate of the ink is 3×104 (sec−1), and
- σγ=4×104:
- shear stress (Pa) when the shear rate of the ink is 4×104 (sec−1).
An ink jet recording ink set comprising a plurality of ink compositions each containing at least a colorant, a water-soluble organic solvent and water, wherein each of said plurality of ink compositions has dynamic viscoelasticity at 20° C. set to satisfy the following expression (VII):
- 1.2 ≤ log G ω = 0.8 ′ - log G ω = 0.6 ′ log 0.8 - log 0.6 ≤ 2 ( VII )
- wherein
- G′ω=0.6:
- storage shear modulus (Pa) when frequency (ω) applied to the ink composition is 0.6 rad/s, and,
- G′ω=0.8:
- storage shear modulus (Pa) when frequency (ω) applied to the ink composition is 0.8 rad/s.
The ink jet recording set according to any one of claims 1, 36 and 9, wherein the colorant is a self-dispersion type pigment.
A process for preparing an ink jet recording ink set comprising a plurality of ink compositions each containing at least a colorant, a water-soluble organic solvent and water, which comprises adjusting said plurality of ink compositions so that a difference in zero shear viscosity which is a value at sin θ=0 (θ=0) is 0.2 mPa·s or less and a difference in the slope of a sin θ vs. viscosity curve is within 0.04, said sin θ vs. viscosity curve being obtained by carrying out rolling-ball system measurement of the viscosity of each of the ink compositions under the temperature condition of 20° C. while changing an inclination angle θ to predetermined angles, determining the viscosity at the predetermined angles, and plotting the sin θ and the viscosity along the abscissa and the ordinate, respectively.
A process for preparing an ink jet recording ink set comprising a plurality of ink compositions each containing at least a colorant, a water-soluble organic solvent and water, which comprises adjusting flowing characteristics at 20° C. of each of said plurality of ink compositions to satisfy the following expression (I):
- 0.6 ≤ log σ γ = 5 · - log σ γ = 3 · log 5 - log 3 ≤ 1 ( I )
- wherein
- σγ=3:
- shear stress (Pa) when the shear rate of the ink is 3 (sec−1), and
- σγ=5:
- shear stress (Pa) when the shear rate of the ink is 5 (sec−1).
A process for preparing an ink jet recording ink set comprising a plurality of ink compositions each containing at least a colorant, a water-soluble organic solvent and water, which comprises adjusting flowing characteristics at 20° C. of each of said plurality of ink compositions to satisfy the following expression (IV):
- 0.6 ≤ log σ γ = 4 × 10 4 · - log σ γ = 3 × 10 4 · log ( 4 × 10 4 ) - log ( 3 × 10 4 ) ≤ 1 ( IV )
- wherein
- σγ=3×104:
- shear stress (Pa) when the shear rate of the ink is 3×104 (sec−1), and
- σγ=4×104:
- shear stress (Pa) when the shear rate of the ink is 4×104 (sec−1).
A process for preparing an ink jet recording ink set comprising a plurality of ink compositions each containing at least a colorant, a water-soluble organic solvent and water, which comprises adjusting dynamic viscoelasticity at 20° C. of each of said plurality of ink compositions to satisfy the following expression (VII):
- 1.2 ≤ log G ω = 0.8 ′ - log G ω = 0.6 ′ log 0.8 - log 0.6 ≤ 2 ( VII )
- wherein
- G′ω=0.6:
- storage shear modulus (Pa) when frequency (ω) applied to the ink composition is 0.6 rad/s, and,
- G′ω=0.8:
- storage shear modulus (Pa) when frequency (ω) applied to the ink composition is 0.8 rad/s.
Dependencies are inferred from the claim text.