摘要 |
<p>The following water soluble materials are all satisfactory internal accelerators for otherwise conventional zinc phosphate conversion coating solutions: reducing sugars, starch, urea, and poly{acrylates and methacrylates}. Concentrates including these ingredients and otherwise conventional constituents of zinc phosphate conversion coating compositions, except for excluding conventional accelerators other than nitrate, are stable in composition during storage, unlike most conversion coating compositions containing conventional accelerators. Thus concentrates according to the invention are practical single-package concentrates that can be made into working phosphating compositions by dilution with water only.</p> |