银器处理的一种新方法

巯基苯基四氮唑(PMTA)是近年来发现的优良的防银变色剂。本文采用了甲酸并添加了少量的 PMTA 对银器表面的锈垢进行了处理,效果较为满意。从一批墨西哥银元的试验中可以证明,这种处理方法对银器具有抗变色作用,其效果 PMTA 比苯骈三氮唑(BTA)好,因 BTA 与银形成的配合物膜是呈线型或网状型的结构,而 PMTA 与银形成致密的配合物膜,这膜具有面型的结构,它能更有效地阻断各种腐蚀介质与银的反应。

A new treatment of silverware

The 1-phenyl-5-mercaptoterazole(PMTA)is an excellent antitarnish agent for silver,which is discovered recent years.In this paper,formic acid with a small rust on the surface.The treatment is very successful.In addition,a lot of Mexican silver coins treated by this method also showed that the treatment could prevent silver from tarnish.The effect of the antitarnish of PMTA is better than that of benzotriazole(BTA).Probably it may have reason as follows:PMTA can react with silver to form a dense coordination film of plane formula on the surface of silver,but BTA reacts with silver only to form a coordination film of linear or net.So the film of PMTA is more effective to interrupt the chemical-reactions between corrosive medium and the silver.