Preparation And Research On Coating-resin Of Carriers For Electrostatic Image

The method that makes the image information visualization with the electrostaticimage technology (electrophotography) is being used in various fields. In theelectrophotography, an electrostatic image can be formed on the photoreceptor throughcharging and exposing. The developer containing toner makes the electrostatic imagedevelop.Then it is visualized through transferring and fixing. The developer includestwo-component developer containing a toner and a carrier, and one-component developercontaining toner only.The carrier constituting two-component developer is comprised of a magnetic carriercore material and a resin coated on the surface.The resin is used for coating the magneticcore particles.Its performance directly affect the effect of development. Therefore, thestudy of the coating-resin has become a hot research currently.Taking methylmethacrylate (MMA) and styrene (St) as the raw material, calcium phosphate which wasmade of anhydrous calcium chloride and sodium phosphate as inorganic dispersant,sodium dodecyl benzene sulfonate(SDBS) as anionic surfactant, benzoyl peroxide (BPO)as an initiator, F01as a chain transfer agent in the suspension polymerization in aqueoussolution, the resin of MMA-St was prepared in this paper. Researched the influence ofmonomer ratio (MMA ratio and the amount of styrene), amount of initiator, chain transferagent, and temperature on the weight-average molecular of the resin. Too large or toosmall molecular would affect properties of the carrier-coated.The desired weight-averagemolecular needs to control between100,000to150,000. Prefer the resin whose molecularis approximately150000.Chose four factors:the amount of initiator and chain transferagent, temperature and monomer ratio as the research objects. By designing orthogonalexperiment of four factors and three levels, the optimum condition of resin preparation wasdetermined:BPO was1.5g, the monomer ratio was4:1, F01was0.1g, the reactiontemperature was75℃, stirring rate was400r/min, CaCl2was5.5g, Na3PO4was11.2g,SDBS was5g.The weight-average molecular of resin was144000.The resin under thisprocess conditions was used for coating the carrier core particles.The volume resistance ofcarriers would become larger after being coated on the surface of carrier core particles.Researched the effect of temperature and humidity and the rate of the resin-coated onvolume resistance and charge of carriers. The volume resistance was inversely proportionalto the charge. At the same temperature, the lower the humidity was, the greater the volumeresistance. Under the condition of similar humidity, lower temperature would result inhigher volume resistance. When the resin coated rate declined, the volume resistancewould decrease. Print results of carriers showed that related indicators of carriers has achieved industry requirements.