| 摘要 |
<p>An aqueous protective coating composition particularly useful for can coatings containing an aqueous dispersed, microgel polymeric binder, which is made by a process of: (a) copolymerizing ethylenically unsaturated monomer, including carboxyl functional monomer, by in-situ non-aqueous polymerization in the presence of epoxy resin and in the presence of at least 1 % peroxide initiator based on the weight of the monomer copolymerized, at temperatures between about 80 DEG C and 180 DEG C to produce a carboxyl functional acrylic grafted epoxy copolymer having an Acid Number above 30; (b) dispersing the carboxyl functional acrylic grafted epoxy copolymer into water by neutralising the carboxyl groups on the acrylic grafted epoxy copolymer to provide a preformed aqueous dispersion of acrylic grafted epoxy copolymer (c) dispersing a high molecular weight, multifunctional branched epoxy resin having functionality above two into the preformed aqueous dispersion of acrylic grafted epoxy copolymer; and (d) crosslinking the multifunctional branched epoxy resin with the carboxyl functional acrylic grafted epoxy copolymer to produce stablized, aqueous dispersed, microgel polymer particles having a mean particular size less than 1 micron.</p> |
