High performance ink is ink that satisfies all of the following requirements.
If priority is focused for example on color reproducibility when examining ink compositions, and the concentration of the colorant is increased, it becomes difficult to secure the necessary head discharge characteristics and reliability. On the other hand, if a moisturizing agent is added in large amounts in order to increase reliability, ink drying becomes an issue, and if solidification is suppressed, the speed at which ink permeates paper and dries is significantly delayed. Furthermore, the generation of foreign material from ink significantly hinders the long-term stable use of inkjet printers.
When there is a significant amount of foreign material, it is generated due to the printer components being affected by the ink solvent and by deposition of the added colorant. However, when measures are adopted to avoid this, restrictions are placed on the additives, thereby making it difficult to secure image quality, drying performance, and head discharge characteristics.
The requirements listed in A, B, C, and D above are contradictory performance factors, making it technically difficult to satisfy these requirements and achieve a good balance. Ink compositions are realized through “Combinational Excellence = Artistic Skill” in combining colorants ― moisturizing agents ― surfactants ― other additives ― and organic solvents.
Permeation into paper must also be considered. Surfactants and other additives are often used to improve drying performance, but the result is ink that can cause significant bubbling like a detergent. When air bubbles enter the head of an inkjet printer, they can cause problems with ink discharge and a decrease in reliability. Therefore, ink compositions that easily eliminate bubbling must be formulated.