Image forming method and ink set

1. An image forming method comprising:

a step of preparing an ink which contains a coloring material, water, and an organic solvent A having a vapor pressure of 0.20 kPa or less at 20° C. and in which a content of the organic solvent A is 10% by mass or greater with respect to a total amount of the ink;

a step of preparing an aggregating liquid which contains an aggregating agent aggregating components in the ink and water;

a step of preparing an overcoat liquid which contains a resin and an organic solvent B having a vapor pressure of 2.50 kPa or greater at 20° C. and in which a content of the organic solvent B is 25% by mass or greater with respect to a total amount of the overcoat liquid;

a step of applying the aggregating liquid onto an impermeable base material;

a step of applying the ink to at least a portion of a region in the impermeable base material to which the aggregating liquid has been applied according to an ink jet method to form an image; and

a step of applying the overcoat liquid onto the region to which the aggregating liquid has been applied in the impermeable base material, on which the image has been formed, to form an overcoat layer,

wherein a content of the water in the overcoat liquid is 20% by mass or less with respect to the total amount of the overcoat liquid.

2. The image forming method according to claim 1 ,

wherein at least one of the organic solvent A contained in the ink has a vapor pressure of 0.10 kPa or less at 20° C.

3. The image forming method according to claim 1 ,

wherein in the overcoat liquid, a content of an organic solvent which has a vapor pressure of 0.10 kPa or less at 20° C., is 10% by mass or less with respect to the total amount of the overcoat liquid.

4. The image forming method according to claim 1 ,

wherein in a case where a unit of an SP value is set as MPa 1/2 , an average SP value of the organic solvents A contained in the ink is set as I SP , and an average SP value of all liquid components contained in the overcoat liquid is set as O SP , an expression of I SP −O SP ≥3 is satisfied.

5. The image forming method according to claim 1 ,

wherein the aggregating liquid contains resin particles.

6. The image forming method according to claim 1 ,

wherein the overcoat liquid contains inorganic particles.

7. The image forming method according to claim 6 ,

wherein at least one kind of the inorganic particles contained in the overcoat liquid has a Mohs hardness of 4 or greater.

8. The image forming method according to claim 1 ,

wherein the impermeable base material is a resin base material.

9. The image forming method according to claim 1 ,

wherein the aggregating agent is at least one selected from the group consisting of a polyvalent metal compound, an organic acid or a salt thereof, and a metal complex.

10. The image foaming method according to claim 1 ,

wherein a ratio of a mass of the aggregating liquid to be applied per unit area to a mass of the overcoat liquid to be applied per unit area is 1.0 or greater.

11. An ink set comprising:

an ink which contains a coloring material, water, and an organic solvent A having a vapor pressure of 0.20 kPa or less at 20° C. and in which a content of the organic solvent A is 10% by mass or greater with respect to a total amount of the ink;

an aggregating agent which aggregates components in the ink and an aggregating liquid containing water; and

an overcoat liquid which contains a resin and an organic solvent B having a vapor pressure of 2.50 kPa or greater at 20° C. and in which a content of the organic solvent B is 25% by mass or greater with respect to a total amount of the overcoat liquid,

wherein a content of the water in the overcoat liquid is 20% by mass or less with respect to the total amount of the overcoat liquid.