Photographic material
AssigneeCiba-Geigy Corporation
InventorIvan Tomka
Life of this patent
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Abstract
Novel gelatins which contain microgel, oligomers of .alpha.-gelatin, .alpha.-gelatin and not more than 25 percent by weight of fragments of .alpha.-gelatin (peptides) with a molecular weight of less than 9.times.10.sup.4 are used as binders in layers of photographic materials. Photographic additives are readily compatible with the gelatins. Furthermore, the good viscosity characteristics and short setting times of the gelatins also facilitate the production of photographic materials.
Claims10
A photographic material which contains, on a base, in at least one layer, as a binder, gelatin which contains microgel, oligomers of .alpha.-gelatin, .alpha.-gelatin and fragments of .alpha.-gelatin (peptides), wherein the gelatin contains less than 25 percent by weight of fragments of .alpha.-gelatin (peptides) with a molecular weight of not more than 9.times.10.sup.4.
In a process for the production of photographic materials the improvement which comprises coating on a support at least one layer containing a gelatin which contains microgel, oligomers of .alpha.-gelatin, .alpha.-gelatin and fragments of .alpha.-gelatin (peptides), wherein the gelatin contains less than 25 percent by weight of fragments of .alpha.-gelatin (peptides) with a molecular weight of not more than 9.times.10.sup.4 prepared by extracting or melting out a new material which has been subjected to an alkaline pre-treatment with an aqueous calcium hydroxide or sodium hydroxide solution at a temperature of from 70.degree. to 100.degree. C. for 5 to 120 minutes at a pH-value of from 5.5 to 7.
Dependencies are inferred from the claim text.