Research Of High-Gloss Ink-Jet Pring Paper With SiO₂ As Ink Absorption Media

With development of digital colorful equipments, Ink-jet printing technology was spreading towards offices and families. The demand for colorful ink-jet printing was increasing obviously. Colorful ink-jet printers were increasing at the rate of 19% per year. The increase of consumption on ink-jet materials such as ink-jet printing paper was striking, in 2007 the domestic market capacity was about 100 million square meters. During the development of ink-jet printing technology, ink-jet printing media was realized to affect the ink-jet printing quality considerably. When liquid ink drops contacted the surface of the paper, the disperse shape of the ink drops made great affection on image definition. The ability and the speed of ink absorption were the main reasons affecting the printing image quality, and they were also the main problems in the ink-jet printing technology. The ink absorption media of porous ink-jet printing paper was Al₂O₃ normally at present. The ink-jet printing paper with SiO₂ as ink absorption media had the advantages of high surface hardness, excellent anti-scratch performance and low cost, but it also had some disadvantages such as the surface crack and high coating viscosity, these affected the application of SiO₂ to some extent.The ink absorption property of SiO₂ and other inorganic pigments, ink absorption performances of SiO₂ with different specific surface area and the surface properties of ink-jet printing paper were discussed. The application method of SiO₂ was decided. The dispersing agents, dispersing method and the stability of silica aqueous dispersion were discussed. It turned out that when pH was about 3.5 the electrostatic repulsion between particles was highest because the particles had the highest surface charge density. The optimum dispersion was obtained using cationic dispersing agent PDADMAC.The relation between degree of polymerization and the content of PVA and the ink-jet printing coating properties were discussed. It turned out that when PVA content was 1.5%, the anti-scratch and ink absorption properties were acceptable, the image color was vivid, and the image was clear. The cross linking reactions between PVA and some cross linkers were compared, and H₃BO₃ was selected as cross linker to discuss the affection on the anti-water and anti-scratch properties of ink-jet printing paper.Fixing ability of some fixing agents on ink dyes were compared and the application of mixture of different polymers was decided. Fixing and anti-water properties of the ink-jet printing paper were confirmed by image bleeding and ink outflow test.During the research of the coating parameters and coating technique, it was discovered that coating viscosity was related to the content of SiO_>2, PVA and solvent. The suitable coating viscosity range was ascertained. The affection of dry temperature on paper's anti-water property was discussed, it turned out that the anti-water, anti-scratch and anti-crack properties of ink-jet printing paper were optimum when dry temperature was 80～90℃.After coating with equipment of Lucky film company using the recipe ascertained by the researches in this paper, it was verified that main parameters such as coating viscosity, surface tension, coating temperature and dry temperature met the equipment demand.After various test, it turned out that surface circumstance, ink absorption, fixing properties, degradation and color density could satisfied the using demand.