Image forming method
An image forming method including adhering a pretreatment liquid to a surface of a recording medium bearing a coat layer thereon; adhering an ink including a colorant, an organic solvent, a surfactant and water to the surface of the recording medium to form an image of the ink; and adhering an aftertreatment liquid to the image-bearing surface of the recording medium to form a protective layer on at least the image on the recording medium. The organic solvent of the ink includes a polyalcohol having an equilibrium moisture content of not less than 30% by weight at 23° C. and 80% RH; a β-alkoxy-N,N-dimethylpropionamide compound, and at least one compound selected from 1,3-dioxane-4-methanol compounds, oxetane compounds, and sebacic acid dialkylester compounds.
1. An image forming method comprising:
adhering a pretreatment liquid to a surface of a recording medium bearing a coat layer thereon, wherein the recording medium includes a support, and the coat layer is located on at least one surface of the support;
adhering an inkjet ink including a colorant, an organic solvent, a surfactant and water to the surface of the recording medium, to which the pretreatment liquid has been adhered, to form an image of the ink; and
adhering an aftertreatment liquid to the surface of the recording medium, on which the image has been formed, to form a protective layer at least on the ink image on the recording medium,
wherein the organic solvent of the ink includes:
a polyalcohol having an equilibrium moisture content of not less than 30% by weight at 23° C. and 80% RH;
an amide compound having the below-mentioned formula (I):
wherein R represents an alkyl group having 4 to 6 carbon atoms; and
a compound having a formula selected from the group consisting of the below-mentioned formulae (II) to (IV):
wherein R 1 represents a hydrogen atom, or an alkyl group having 1 or 2 carbon atoms, and R 2 represents an alkyl group having 1 to 4 carbon atoms;
wherein R′ represents an alkyl group having 1 or 2 carbon atoms, and R 3 represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cyclic alkyl group, or an aromatic group; and
wherein each of R 4 and R 5 independently represents an alkyl group having 1 to 8 carbon atoms.
2. The image forming method according to claim 1 , wherein the amide compound has the following formula (I-1):
3. The image forming method according to claim 1 , wherein the pretreatment liquid includes a water-soluble aliphatic organic acid having the following formula (V):
wherein R 6 represents a hydrogen atom, or a methyl group substituted with a hydroxyl group or a carboxyl group; R 7 represents a methyl group, a methyl group substituted with a carboxyl group, or a methyl group substituted with a hydroxyl group and a carboxyl group.
4. The image forming method according to claim 3 , wherein the pretreatment liquid further includes a water-soluble organic monoamine compound.
5. The image forming method according to claim 4 , wherein the water-soluble organic monoamine compound has one of the following formulae (VI) and (VII):
wherein each of R 8 , R 9 and R 10 independently represents a hydrogen atom, an alkoxyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 8 carbon atoms, a hydroxyethyl group, or a hydroxypropyl group, wherein R 8 , R 9 and R 10 are not simultaneously a hydrogen atom; and
wherein R 11 represents a hydroxymethyl group; R 12 represents a methyl group, an ethyl group, or a hydroxymethyl group; and R 13 represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a hydroxymethyl group.
6. The image forming method according to claim 1 , wherein the pretreatment liquid includes at least one of ammonium lactate, ammonium acetate, and a water-soluble cationic polymer.
7. The image forming method according to claim 1 , wherein the aftertreatment liquid includes at least one water-dispersing resin selected from the group consisting of acrylic resins, styrene-acrylic resins, urethane resins, acrylic-silicone resins, and fluorine-containing resins.