GB539066A - Photographic blue print paper and sensitizing composition therefor - Google Patents

Abstract

539,066. Photographic blue-print processes. ELLIOTT CO., B. K. Jan. 24, 1940, No. 1460. Convention date, Feb. 20, 1939. [Class 98 (ii)] A blue-print sensitizing composition comprises an aqueous solution of a ferric alkali metal salt of an organic acid, an alkali metal ferrocyanide, and a hydroxyalkylamine salt of a polybasic acid, and may also comprise an alkali metal ferricyanide. Salts such as monohydroxymethylamine oxalate, dihydroxy isopropylamine oxalate, trihydroxyethylamine tartrate, trihydroxyisopropylamine borocitrate, and trihydroxy butylamine glycerophosphate may be used. The hydroxyalkylamine salt may be a complex salt containing a metal of the first or second group of the Periodic System, which does not form a water-insoluble compound with ferrocyanide or ferricyanide ions, such as trihydroxyethylamine potassium oxalate dihydroxy isopropylamine sodium tartrate, and trihydroxymethylamine ammonium malate. Magnesium, lithium, strontium, calcium salts are also referred to. Complex salts of a tribasic acid such as phosphoric, citric, or boric acid and one or two of the above-mentioned metals may be employed. Examples specified are mono dihydroxyethylamine sodium hydrogen phosphate, mono trihydroxyisopropyl amine sodium magnesium citrate, and monohydroxymethylamine potassium glycerophosphate. Complex salts of a di- or tri-basic acid and two or three different mono-, di-, or trihydroxyalkylamines, such as dihydroxyethyl-aminetrihydroxymethylamine oxalate, trihydroxyisopropylamine-trihydroxyethylamine hydrogen phosphate, and mono-hydroxyethylamine-trihydroxyethylamine - trihvdroxypropyl - amine citrate. Acidic and basic components capable of forming the above complex salts may be added to the solution. In examples, the compositions include ferric ammonium oxalate, potassium ferricyanide, sodium ferrocyanide, and (1) tri-hydroxyethylamine oxalate, (2) dihydroxyethylamine potassium oxalate, (3) trihydroxyethylamine and oxalic acid, (4) trihydroxyisopropylamine and potassium bioxalate, and (5) trihydroxvethylamine, potassium oxalate, and oxalic acid. Small amounts of oxalic, citric, tartaric, or phosphoric acid may be added. Wetting agents such as saponine or sulphonated fatty acids and catalysts such as salts of vanadic acid may also be added. Specification 418,369 is referred to.