Abstract: The present invention relates to an ink composition containing fine particles having an amino group on surfaces thereof. According to the invention, there can be provided an ink composition which prevents volatilization or bleedout of an amine compound to cause no discharge of the amine compound into the environment and is also excellent in curability. Further, there can be provided an ink composition which is excellent in curing efficiency, surface curability and internal curability, and can prevent the occurrence of cracks.

Abstract: An ink jet recording material of the invention includes a polyolefin resin-covered paper substrate, an ink absorption layer and a layer principally including colloidal silica in this order at one face of the substrate, and a backcoat layer at an opposite face of the substrate. An MD direction Taber stiffness of the substrate is at least 3 mN·m. The ink absorption layer principally includes fumed silica, and the backcoat layer is principally polyurethane resin. The ink absorption layer includes a thioether-based compound, and a polyolefin resin layer at a side of the substrate at which the ink absorption layer is to be provided includes an fluorescent brightening agent and a white pigment. A solid content coating amount of the colloidal silica is 0.05 to 0.3 g/m2, and a solid content coating amount of the polyurethane resin is 0.8 to 1.5 g/m2. A 20° glossiness of a blank portion of a face of the recording material that features the ink absorption layer is 40 to 60%.

Abstract: The present invention provides an ink jet recording ink which has excellent stability, high coloration on regular paper, high glossiness on gloss paper and excellent discharge stability of an ink from an ink jet head. This ink jet recording ink uses 2-methyl-2-propyl-1,3-propanediol. The added amount of 2-methyl-2-propyl-1,3-propanediol is no less than 0.1% by weight and no more than 2.0% by weight.

Abstract: An ink-jet printing head according to the present invention is constituted so that two reservoirs 3 and 4 are formed with each pressure generating chamber 2 between the two reservoirs, the pressure generating chamber 2 communicates with at least one reservoir 3 or 4 via an ink supply port 5 or 6, adjacent nozzle communicating holes are arranged in approximately opposite positions with the center in the longitudinal direction of the pressure generating chamber 2 between the adjacent nozzle communicating holes and arranged zigzag with the adjacent nozzle communicating holes shifted in the longitudinal direction of the pressure generating chamber 2 and the height M of a partition for partitioning the nozzle communicating hole 7 or 8 which is a through hole and the adjacent pressure generating chamber 2 is approximately equal to the height of a partition N between the pressure generating chambers 2.