Surfacing of polyolefin objects with antimicrobial material

In a rotational molding method for fabrication of a hollow form plastic product in a rotational molding cycle wherein plastic particles are charged to a rotational mold, the mold is closed, heated to a molding temperature while being rotated about its major and minor axes for a time sufficient to form said molded product and the mold is cooled to a demolding temperature, opened and the molded product is ejected, the improved method for imparting anti-microbial activity to the exterior surface of said molded product which comprises:

• applying to a selected area of the interior surface of said rotational mold at substantially the demolding temperature a coating comprising
• i. from 0.5 to 5 weight percent of an anti-microbial metal selected from the group consisting of elemental and ionic silver, zinc, copper and cadmium deposited on a solid carrier, and
• ii. from 95 to 99.5 weight percent of a polyolefin fusible solid selected from the group consisting of a hydrocarbon resin having a viscosity at 177 degrees F. in excess of 20, a polyolefin having a melt index less than 50, and mixtures thereof;
• and
• b. continuing said rotational molding cycle to obtain a molded, hollow form plastic product having said anti-microbial composition fused into the wall of said product.