| 摘要 |
<p>A process is disclosed of precipitating high chloride {100} tabular grain emulsions having an average tabular grain thickness of less than 0.3 micrometer. Higher average grain equivalent circular diameters and aspect ratios are realized by employing a gelatino-peptizer during at least a portion of the precipitation that satisfies the formula:<MathDetails id="matha01"><MathText><![CDATA[ <math display="block"><mrow><mtext>(Pro + Hypro) ÷ (Ser + Thr) = <4.0</mtext></mrow></math><img id="ia01" file="imga0001.tif" wi="68" he="4" img-content="math" img-format="tif" /> ]]></MathText></MathDetails> wherein Pro, Hypro, Ser and Thr represent the proline, hydroxyproline, serine, and threonine amino acid components, respectively, of the gelatino-peptizer. When the formula satisfying gelatino-peptizer is present during grain nucleation and contains at least 40 micromoles of methionine per gram of gelatino-peptizer, the high chloride {100} tabular grains account for a high proportion of total grain projected area. When the formula satisfying gelatino-peptizer is present during grain growth and contains <4 micromoles of methionine per gram of gelatino-peptizer, the time required to prepare the emulsion is reduced.</p> |
