COATING AGENT FOR BUILDING SCREW

PURPOSE: To obtain a coating agent with which a low initial torque, a reduced drilling time, and excellent working efficiency are obtained and which has satisfactory antiseizing performance by incorporating a water-soluble acrylic resin and a wax. CONSTITUTION: A (meth)acrylic ester is polymerized with 10-20wt.% (meth) acrylic acid, e.g. by solution polymerization in an organic solvent such as an alcohol or emulsion polymerization in water. The resultant polymer is neutralized with a volatile amino to obtain a water-soluble acrylic resin (A) having a weight-average mol.wt. of 10,000-100,000 and a glass transition temp. of 0-50 deg.C. A melt of a wax is mixed with about 1-30wt.% higher fatty acid and further with a volatile amine. The resultant mixture is gradually added to and emulsified into water heated to 95 deg.C or higher. The emulsion is cooled to 40 deg.C or lower to obtain a wax emulsion (B). The ingredients (A) and (B) are mixed at room temp. in an (A)/(B) weight ratio of (70-99)/(30-1) on a solid basis to produce a coating agent. A screw is dipped in this coating agent diluted with water, and is then centrifuged to remove the excess coating agent and dried.