Patent ID: 7413772

Claim:
A method for coating thermoplastic resin beads for use in imitation pearls, the method comprising the steps of: dissolving 12-29 wt % of pyroxylin into a mixed solution of 14-18 wt % of acetone, 36-42 wt % of ethylacetate, 18-22 wt % of butylacetate, and 3-6 wt % of benzene to form surface treatment compound (A); adding the thermoplastic resin bead to surface treatment compound (A) to form a treated thermoplastic resin bead; and coating the treated thermoplastic resin bead with at least one of a compound for an under coat (B), a compound for a mid coat (C) and a compound for a top coat (D), wherein the compound for the under coat (B) is prepared by dissolving 22-33 wt % of the pyroxylin into a solvent of 33-38 wt % of ethylacetate and 33-38 wt % of amylacetate and adding 1-5 wt % of a pigment thereto, the compound for the mid coat (C) is prepared by dissolving 22-33 wt % of the pyroxylin into a solvent of 25-29 wt % of ethylacetate and 40-44 wt % of amylacetate and adding 1-5 wt % of a pigment thereto, and the compound for the top coat (D) is prepared by dissolving 22-33 wt % of the pyroxylin into a solvent of 46-49 wt % of amylacetate and 20-26 wt % of ethylacetate and adding 0.1-1 wt % of a pigment thereto.