Hardening photographic gelatine emulsions and gelatine solutions

摘要

Gelatine is hardened by the addition of diketones such as diacetyl acetylcaproyl, acetylbenzoyl or dibenzoyl. Other hardening agents such as formaldehyde or chrome alum may be added. The diketones may be added in solution in methanol. The hardening effect is greatest at the pH value of 8.