New Type of Polymer Coating System onto Metal Surface from Polymer Emulsion

众所周知，电沉积是一种在金属表面上涂覆聚合物的技术。最近，我们提出了一种类似的涂层工艺，只需将聚合物浸入pH值调节到3以下的阴离子聚合物乳液中，就可以在不施加电流的情况下将聚合物沉积在阳极氧化的铝板上。我们把这种涂覆过程称为“化学沉积”。根据对其进行的一系列基础性研究，如下文所强调的，它还存在一些亟待改进的严重问题。这个项目的目的是改善他们，我们已经成功了：1。由于使用盐酸来调节ph值，导致涂料的性能不高。我们可以用甲酸、丙酸等有机酸代替。2. 涂层厚度随乳液浴重复使用次数的增加而减小。每次浸铝时，铝板上积聚的铝离子会溶解，用一些掩蔽剂可以改善这一问题。3. 由于乳化剂分子，尤其是游离的乳化剂分子对聚合物的化学沉积有不良影响，我们不得不使用无乳化剂的聚合物乳液。无乳化剂乳液的长期贮存稳定性不佳。在聚合物乳液的制备中应用可聚合乳化剂可以改善这一问题。

It is well knowen that electrodeposition is used worldwide as a technique for polymer coatings onto a metallic surface. Recently we have proposed a similar coating process in which the oplymer could be deposited onto an anodized aluminum plate without applied electric current only by immersing it into an anionic polymer emulsion the pH of which was adjusted below about 3. We have termed this coating process as "chemical deposition". According to a series of fundamental investigations on it, as pointed in underlines below, there were some serious problems which is required to improve for applying it industrially. The purpose of this project is to improve them and we have succeeded it as follows:1. We had usd hydrochloric acid to adjust the pH. Because of it, the properties of coatings had no high quality. We colud apply some organic acids such as formic acid and propionic acid in place of it. 2. The coating thickness decreased with an increase in the number of repeated use of the emulsion bath. We could improve the problem to use some masking agents for aluminum ions which are accumulated therein by dissolving from the aluminum plate every dipping. 3. We had to use emulsifier-free polymer emulsion, because emulsifier molecules, especially free ones gave a bad influence in the chemical deposition. the emulsifier-free emulsion had no good long storage stability. We could improve the problem by applying a polymerizable emulsifier in the preparation of polymer emulsion.