Preparation Of High Quality Color Ink-jet Matt Paper

In order to obtain high quality color ink-jet papers, in the process of study, print performance of samples were evaluated with a series of simple, rapid, effective methods. At the same time, samples used different pigments (amorphous silica, grounded calcium carbonate and titanium oxide) were compared; Effects of different binders (polyvinyl alcohol, PVP, SBR latex and St-BA cationic latex) on performance of samples were analyzed; Effects of two kinds of fixative on water resistance of samples were analyzed and compared. Such measurement techniques include: color density; print contrast; color gamut in CIE L~*a~*b~* color space; sharpness of text and edge definition of lines; resolution of samples; color difference (AE) of samples after immersion in water and wet rub-off fastness. Main results have been obtained as follows:Grounded calcium carbonate or titanium oxide used as a co-pigment together with silica could modify its rheology, but their addition could engender negative influence on the color optical density, print contrast, color gamut and edge acutance of lines, especially the effect of titanium oxide on the print quality is evident.Polyvinyl alcohol (PVOH) as the binder used in color ink-jet paper not only on color optical density but also on color gamut is superior when compared with SBR latex. Aiming at the drawbacks of PVOH in water-resistant property, glyoxal as a cross-linking agent was used in this thesis to modify the PVOH so that the Wet Surface Intensity of the coating and the wet rub-off fastness of the printing pictures were enhanced.St-BA cationic latex can be combined in a kind of unsolvable salt with the dye molecule in ink-jet printing inks. So it could improve the wet strength of the printing pictures acted as the dye-fixing agent in a way. Meantime, the wet rub-off fastness of the printing pictures could be increased because of the abrasion resistance of St-BA cationic latex.Through researching on the principle of ink-jet printing and the formation of print dots, the relations between resolution and ink droplet contact angle with the surface of the coating were found: the bigger the contact angle is, the smaller the diameter of the formative dot is and the more print dots on every unit length are, thus, the resolution of the color ink-jet paper will be higher; also the research indicated that the St-BA latex could enlarge the contact angle between the ink droplet and the surface of the paper as a supplementary binder used in color ink-jet paper. The resolution is improved when the dosage of the St-BA cationic latex reached 1/3 to 1/2 of the whole binders.PVP has superior effect on improving the color optical density of the printing pictures by its adsorption and complexation. By considering the hygroscopic and hydrolyze, the dosage of PVP should be strictly controlled from 3 pts to 5 pts per 100 pts pigments. Excessive dosage would decline the quality of the printing pictures and increase the color difference after immersion in water.The dye-fixing agent used can not only decrease the color difference after immersion in water, but also improve the optical density and saturation of color by means of the research. Meanwhile, it is demonstrated that increasing the dosage of the dye-fixing agent will not improve the wet rub-off fastness of the printing pictures, but decrease the color fastness of printing pictures.