Dispersion, inkjet ink, method of manufacturing dispersion, method of manufacturing inkjet ink, and printed matter

A dispersion for ink comprising:

• a dispersion medium;
• pigment having an average particle diameter of not more than 200 nm;
• a polymer dispersing agent containing a first resinous dispersing agent and a second resinous dispersing agent;
• and
• an ionic compound;
• wherein a concentration of the pigment is confined to 2 to 30 parts by weight based on 100 parts by weight of the dispersion medium, a mixing amount of the first resinous dispersing agent is confined to 10% to 60% based on a total weight of the pigment, the second resinous dispersing agent is a resin having a basic terminal and a mixing amount of the second resinous dispersing agent is confined to 1% to 30% based on a total weight of the pigment, and a mixing amount of the ionic compound is confined to 0.01 to 20 parts by weight based on 100 parts by weight of a total of the dispersion medium.

A method for manufacturing a dispersion for inkjet ink comprising:

• adding powder having an average particle diameter of not more than 300 nm to a dispersion medium at a mixing amount of 2 to 60 parts by weight based on 100 parts by weight of the dispersion medium;
• mixing a first resinous dispersing agent with the dispersion medium at an amount of 1 to 60% by weight based on a weight of the powder to coat the powder with the first resinous dispersing agent;
• mixing a second resinous dispersing agent with the powder at an amount of 1 to 30% by weight based on the powder to further disperse the resin-covered powder;
• and
• adding an ionic compound to the dispersion medium at a mixing amount of 0.01 to 40 parts by weight based on 100 parts by weight of the dispersion medium.

A method for manufacturing an inkjet ink comprising:

• adding powder having an average particle diameter of not more than 300 nm to a dispersion medium at a mixing amount of 2 to 60 parts by weight based on 100 parts by weight of the dispersion medium;
• mixing a first resinous dispersing agent with the dispersion medium at an amount of 1 to 60% by weight based on a weight of the powder to coat the powder with the first resinous dispersing agent;
• mixing a second resinous dispersing agent with the powder at an amount of 1 to 30% by weight based on the powder to further disperse the resin-covered powder;
• and
• adding an ionic compound to the dispersion medium at a mixing amount of 0.01 to 40 parts by weight based on 100 parts by weight of the dispersion medium.