| 摘要 |
In fixing element (I) having metalshaft which canbe hammered in to a part to be joined, extended predominantly in one dimsension, and bearing on atleast part of its surface a coating (II) to modify its friction against a part to be joined by hammering, (II) comprises (a) 40-90 % (all pts. wt.) vinyl acetate copolymer (b) 5-30 % copolymer of (meth)acrylate ester and unsatd. carboxylic acid (c) 0-10 % polyvinyl alcohol (d) 0-5 % plasticiers for (a) and (b) (e) 0-5 % coalescing agent for (a) and (b). Prepn. of (I) by applying, partic. by dipping, mechanical application, or spraying, to at least part of surface of shaft a film of aq. dispersion contg. (a) - (e) and converting into (II) by drying. ADVANTAGE - (I) is economically prepd., requires relatively low hammering force but has substantially increased resistance to being pulled out, which resistance is largely retained on repeated partial extn. and hammering in. |
