Chemical Modification Of SMA And Preparation Of Melamine-Formaldehyde Resign Microcapsules

The functional polymer styrene-maleic anhydride copolymer(SMA) is prepared by using the solution polymerization method, and the esterification agents such as ethanol, butanol, octanol are used on further part esterified modification for the main chain of SMA. The structure of modified SMA is characterized, the effect of the reaction conditions on the yield, viscosity, and degree of esterification for SMA are studied, and the ability to reduce surface tension and the effect of emulsification are determined.The pressure-sensitive color-developing microcapsules are prepared by using the in-situ polymerization method with the SMA aqueous solution, where the colourless dyestuff is used as core and melamine resign as cyst wall. The three-step method is used to control the reaction rate. The effect of the conditions of emulsification, amount of emulsifier, the pH of curing reaction and mass ratio of cyst wall to core materials on the performance of the pressure-sensitive color-developing microcapsules are studied. The results show that the microcapsules prepared with optimized technological conditions are with smooth surface, single core and single wall, the average particle size is 1.8μm, the particle size is distributed in the range of 0.5μm to 2.0 pm, and the rate of solvent evaporation is less than 5.0%.The zinc alkyl salicylic acid resin microcapsules are prepared for the first time, and explore the feasibility of the new process. The effect of the choice of core material solvent, the pH, mass fraction and the quantity of the emulsifier, mass fraction of reagent resin and curing temperature on the performance of reagent resin microcapsules are studied. The results showed that the prepared microcapsules are smooth and spherical with good color density, specially can control the the particle size of reagent resin microcapsules. The average particle size is 2-5 times the average particle size of the pressure-sensitive color-developing microcapsules(4.0μm), particle size distribution is narrow-dispersed (0 to 10μm). The experiment achieves the basic design purpose, which provides a theoretical basis and experimental method for the new one-step coating of the preparation of the carbonless paper.