Study On The Synthesis And Application Of Fixing Agent Of Ink-Jet Paper

With the development of Digital Printing technology, the quality of digital printed paper is becoming more and more important. The colored inkjet paper as a kind of common digital printed paper has a large market share, and its quality has a direct impact on the quality of the final inkjet printing. Currently, in the market the high-grade inkjet paper are mostly coated paper used pigments. Not only the base paper, pigment and adhesive are main factors, but also the additives play a very important role that can not be ignored.As an additive of coating, fixing agent can improve the ink adsorption capacity of inkjet coating to improve the quality of the final inkjet printing. This paper first investigated three commercial cationic fixing agents--Polyethylene amine, Polyethyleneimine and Poly diallyl dimethyl ammonium chloride. The properties of coating, physical properties of paper and inkjet printed performance are studied. The superiority of Poly diallyl dimethyl ammonium chloride as a fixing agent was obtained. Then, under laboratory conditions, different properties of Poly diallyl dimethyl ammonium chloride are obtained by controlling the monomer concentration, initiator dosage. The performance of different Poly dimethyl diallyl ammonium chloride were studied including the physical properties of coated paper and inkjet printed properties, and the performance parameters mainly include:brightness, opacity, roughness, absorbency, color density, gradation, image clarity, colour difference and so on. Finally, on the assumption of improving the quality of inkjet paper, the performance characteristics of Poly diallyl dimethyl ammonium chloride, the optimal dosage and reaction conditions.are determined.The experimental results indicated that the fixing agent have an important influence on viscosity of the coating system, but have little influence on the physical property of paper. The printing quality of inkjet paper can be enhanced obviously; it can fix the ink to the surface of paper and improve the water resistance.The most suitable Poly dimethyl diallyl ammonium chloride for inkjet paper is the one that the molecular weight approximately is100,000; the electric-charge density is5.12mmol/g. The synthesis condition is that:the monomer density approximately45%, the initiator amount used for the pure monomer quality0.5%, the nitrogen time20min, the polymerization temperature55℃, keeping warm four hours to75℃, initiator APS and the chelating agent Na4EDTA concentration100g/l and10g/l respectively. The most suitable coating technical process for fixing agent is:the coating viscosity approximately1670mPas, the rolling temperature40℃, the rolling pressure4MPa. The greatest degree of improving the color density is14.5%, the improvement of water resistance is approximately28.6%, the reduce degree of color different is about24.5%.