| 摘要 |
<p>The use of aluminum sulfate to neutralize alkaline solutions yields a gelatinous precipitate. When neutralization of the solution causes other materials to precipitate along with the gel, filtration of the precipitated materials is very difficult because of the gel. The addition of water soluble magnesium, aluminum, and/or calcium salts as primary neutralizing agents for an alkaline stripper solution of a photoresin, followed by the acidification of the resulting slurry to a pH of from about 2 to about 4 gives a slurry of the precipitated resin which may be filtered quickly.</p> |
