1. Technical Field
The present invention relates to an ultraviolet-curable ink jet composition and a storage body thereof.
2. Related Art
Ink jet recording methods have been rapidly developed in many areas because high-definition images can be recorded by a relatively simple apparatus. Among these methods, various examinations for ink compositions used in an ink jet recording method of curing an ink by ultraviolet irradiation have been conducted. For example, for the purpose of providing an ultraviolet-curable ink jet ink capable of stably landing with high accuracy and having excellent storage stability and curability, JP-A-2005-200560 discloses an ink jet ink composition including at least a pigment, a dispersant having an acid value greater than an amine value, a polymerizable compound, and a photopolymerization initiator, in which the total amount of cationic impurities, metal impurities and strongly acidic substance is 500 ppm or less, and the water content ratio thereof is 1 mass % to 3 mass %.
However, as disclosed in JP-A-2005-200560, when the content of water in the ultraviolet-curable ink jet composition is 1 mass % to 3 mass %, there is a problem in that foreign matter (pigment aggregates) is generated due to the aggregation of a pigment. In addition, when the content of water in the ink jet composition is high, there is a problem in that the curability of the ink jet composition is also lowered. In order to suppress the precipitation of foreign matter and improve the curability of the ink jet composition, it is considered to reduce the content of water in the ultraviolet-curable ink jet composition as much as possible. However, when the water content is excessively reduced, particularly, it takes excessive process and time to remove water from a polymerizable compound, and, as a result, the efficiency of manufacturing the ultraviolet-curable ink jet composition is lowered.