Synthesis Of Water-Soluble Acrylic-Styrene Resin For Water-Based Ink

In the research acrylic-styrene resin was synthesized for water-based ink as the link material. The kind of acrylic-styrene resin was used widely inland. To manufacture the resin could substitute the import products and obtain much conomic benefits.The acrylic-styrene copolymer is the imported resin, which was water soluble, with average number-molecular weight (Mn) about 3000 and a narrow molecular weight distribution, the glass-transition temperature about 100℃, colorless and transparent. The two major difficulties on manufacturing the resin are controlling the molecular weight and narrow molecular weight distribution, making the resin colorless and transparent. In this article four methods are used to overcome the difficulties, selecting the solvent, choosing the initiators, modulating the reaction temperature and improving the production process.Acrylic-styrene resin was synthesized through Semi-continuous solution polymerization process. Water-soluble resin could be synthesized with suitable acid value about 210 and high glossiness, the glass-transition temperature about 100℃. The resin was composed of three monomers which were acrylic, styrene and methyl methacrylate. The weight ratio of the three monomers was 32:60:8.2-methoxy-1-ethanol was selected as the optimum solution through contrast different kinds of solvent. 2-methoxy-1-ethanol solution was conducive to control the molecular weight of the resin due to high boiling point about 12℃. And 2-methoxy-1-ethanol could absolute dissolve the monomers, initiators and the copolymer. More important is that using 2-methoxy-l-ethanol solution could manufacture colorless and transparent resin, which meets the requirements of market.Reaction temperature effects the polymerization in three aspects which were molecular weight of the resin, the atacticity of the copolymer monomers, the half-life period of initiators. High reaction temperature was conducive to decrease the molecular weight of the polymer. The acrylic monomers uniformly distribute at the molecular chain and sufficient atacticity of the copolymer makes for transparent and solvable resin when the reaction temperature higher than 110℃. The half-life period of initiators decreased with reaction temperature increased. And it was necessary to keep the half-life period of initiators in 1 hour for controlling the polymerization reaction.It were studied that different kinds of initiator and initiating system. A series of resin were synthesized which average molecular weight were less than 5000 by using mass portion 4 to 6 of BPO or TBPB as initiator. It is very effective to control the molecular weight of the resin using this method. A theoretical model was made to description the relationship between initiator feeding process and initiator consumption rate. Using BPO and TBPB multiplex initiator, putting 50% of TBPO at the solution, adding 50% TBPB and BPO with monomers was proved to optimum production process. This production process could manufacture resin which was water soluble function, with average molecular weight about 3000 and molecular weight distribution less than 2.5, colorless and transparent, by mass portion 4 of multiplex initiator.The pilot test was conducted in an 8L stainless steel reaction kettle with stirring paddle which was devised by ourselves.