摘要 |
Aqueous dispersions of ethylene/ alpha , beta -unsaturated carboxylic acid interpolymers (e.g., random ethylene/acrylic acid interpolymers) are formed using a mixture of bases at a concentration of at least about 0.2 equivalents of base per mole of alpha , beta -unsaturated carboxylic acid. The dispersions have at least about 10 weight percent dispersed solids and not more than about 1 weight percent of the initial polymer in non-dispersed form. Preferred bases for use in forming the dispersions are ammonium hydroxide and/or alkali metal hydroxides. A mixture of ammonium hydroxide and potassium hydroxide is especially preferred for forming the dispersions with ethylene/acrylic acid interpolymers at an ammonium hydroxide:acrylic acid molar ratio of about 1:1 and a potassium hydroxide:acrylic acid molar ratio in the range of about 0.6-0.8:1. The dispersions are particularly useful in forming thin coatings of adhesive on substrates, such as paper and metal foil, using conventional techniques. |