| 摘要 |
PURPOSE: A modified epoxy resin, its preparation method and a powdered paint composition are provided, wherein the resin is improved in the chipping resistance, the flexibility, the acid resistance and the alkali resistance. CONSTITUTION: The method comprises the steps of dispersing a core cell rubber in at least one low molecular weight epoxy resin selected from a bisphenol-type polyepoxide compound, a novolac epoxy resin and an aliphatic epoxy resin to prepare a core cell-modified low molecular weight epoxide; adding at least one selected from a polyvalent phenol, a novolac epoxy resin and an aliphatic epoxy resin to the obtained core cell-modified low molecular weight epoxide to prepare a core cell-modified high molecular weight epoxide; and adding a lactone compound to the obtained core cell-modified high molecular weight epoxide to prepare a core cell-lactone modified epoxy resin. The obtained modified epoxy resin has an epoxy equivalence of 500-2,000 g/eq and a softening point of 90-140 deg.C. The powdered paint composition comprises 25-40 wt% of the core cell-lactone modified epoxy resin prepared by the method; 30-50 wt% of a carboxy polyester resin; and 10-45 wt% of a flowability improving agent, a UV ray absorbent and a pigment. |
