RU2091858C1 - Method of manufacturing silver bromide/iodide photographic emulsions - Google Patents

Abstract

FIELD: photographic industry. SUBSTANCE: silver bromide/iodide photographic emulsions suitable for holography photographic materials are manufactured using emulsifying, gelatinization, washing, chemical recrystallization in presence of sodium thiosulfate and gold- hydrochloric acid, and optical sensitizing by sodium salt of 3-ethyl- 3'-γ-sulfopropyl-4-keto-4'-phenyl-5-(1"-γ- sulfopropyldihydroquinolidene-4"- ethylidene)thiazolinothiazolcyaninobetaine. According to invention, emulsifying is carried out using controlled two-jet crystallization until microcrystals with average size 0.045-0.05 mcm are obtained; physical recrystallization at pAg 8.6 γ 0.1 and temperature 45-47 C is performed after washing procedure until microcrystals with average size 0.07-0.08 mcm are obtained; before optical sensitizer is added, pAg value is adjusted to 8.6-8.8; and, after sensitizer is added, emulsion is supplemented with 2-heptyl-5-methyl-7-hydroxy-1,2,4- triazaindolicin. EFFECT: improved characteristics of emulsion. 1 tbl

Description

 The invention relates to a method for sensitizing a particularly fine-grained silver halide emulsion, specifically to a photographic emulsion sensitized to radiation from a ruby laser (wavelength 694 nm), which can be used in the manufacture of photographic materials for holography.

 A known method of sensitization of a finely grained silver bromide-silver photographic emulsion with an average microcrystal size of silver halide 0.04-0.05 μm with a maximum spectral sensitivity in the region of 694 G nm with 3-ethyl-3'-γ-sulfopropyl-4-keto-4'- sodium salt phenyl-5- - (1 '' - γ- -sulfopropyl dihydroquinolylidene-4 '' - ethylidene) thiazolinothiazolodianine betaine (compound 1) Positive decision of November 30, 1978 on application N 2437389 / 23-04.

Photographic materials containing this emulsion, when receiving holograms in a pulsed exposure mode, have insufficiently high photosensitivity. The diffraction efficiency of the photographic material is 20%
Closest to the proposed is a method for the manufacture of silver-bromide-silver emulsion by conducting fractional 8-fold emulsification to obtain an average microcrystal size of 0.07 μm, gelation, washing, chemical sensitization in the presence of sodium thiosulfate and hydrochloric acid and optical sensitization by the introduction of 3-ethyl-3 sodium salt '- γ- -sulfopropyl-4-keto-4'-phenyl-5- / 1''- γ- - sulfopropyl dihydroquinolylidene-4''- ethylidene / thiazolinothiazolodianine betaine / compound 1 / with pAg 7.5 / Report of Gosniikhimfotoproekt " a, inv.N 852, N GR 77029911, 1978 / n / s.

 However, this material does not have a sufficiently high photosensitivity when receiving holograms in a pulsed mode.

The purpose of the invention is to increase the photosensitivity of a special fine-grained bromide-silver emulsion to pulsed radiation / χ _max 694 nm /.

The goal is achieved in that in the manufacturing method bromiodoserebryanoy emulsion by conducting emulsification, studeneniya, washing, chemical sensitization in the presence of chloroauric acid and sodium thiosulfate and optical sensitizing dye 1 introduction, emulsification is carried out two-jet method controlled to obtain d _cf. 0.045-0.050 microns after leaching conduct physical maturation at a pAg of 8.6 ± 0.1 and t 45-47 ^o C to obtain d _cf = 0.07-0.08 μm, before the introduction of dye 1, the pAg is adjusted to a value of 8.6-8.8, and after entering As a result of sensitization, an additional 2-heptyl-5-methyl-7-hydroxy-1,3,4-triazaindolycin (compound II) is added to the emulsion in the amount of / 1-3 / • 10 ^-3 mol / mol of silver.

 Example 1

Prepare: 1. an aqueous solution of gelatin by dissolving 68.5 g. inert gelatin in 43 ml. distilled water at t 38 ^o C / pp I /; 2. 50 g of silver nitrate are dissolved in 200 ml of water / pp II /; 3. 34.4 g of potassium bromide and 0.3 g of potassium iodide are dissolved in 400 ml of water / pp III /.

Solutions II and III are divided into 8 equal parts. To gelatin solution I at 38 ^° C and stirring at 1000 rpm, a portion of solution II was added successively over 30 '', then solution III over 1 minute. After emulsification, the average microcrystal size is 0.07 μm.

 The prepared emulsion is gelled, ground into "worms", washed with water and 5-methyl-7-hydroxy-1,3,4-triazaindolycin is added in an amount of 0.35 g per 1 kg of emulsion and potassium bromide to pAg 7.5 ± 0.1 .

The emulsion is melted at t ≠ 46 ^o C and chemical sensitizers are added in an amount of: 0.01 N sodium thiosulfate solution 100 ml / l and 0.08% solution of hydrochloric acid 20 ml / l. Chemical ripening time 70 min. Then dye 1 is introduced into the emulsion in the amount of 5 • 10 ^-4 mol / mol of silver, after 30 minutes. standing at 46 ^° C., irrigation additives are added and watered on a glass or flexible substrate.

 The photographic characteristics of the holographic material containing this emulsion are shown in the table.

 Example 2

The emulsion is prepared by the method of two-jet controlled crystallization. 400 ml of a 0.4% solution of potassium bromide and iodide (0.4 mol of AgI) and nitrate are introduced into 400 ml of a 3% gelatin solution at 4 ^° C ± 0.5 with constant stirring at 1000 rpm for 3.5 minutes. silver. In the process of emulsification support pAg 2 ± 0.1. At the end of the emulsification, 400 ml of a 12% gelatin solution are introduced and the emulsion is stirred for 6 minutes, after which the pAg value is adjusted to 8.6 ± 0.1 with a potassium bromide solution. The average microcrystal size is 0.045-0.050 microns.

The emulsion is gelled, washed in "worms" and subjected to physical maturation at a pAg of 8.6 ± 0.1 and t 47 ± 0.5 ^o C for 90 min to d _cf = 0.08 μm. Then carry out chemical sensitization at a pAg of 8.6 ± 0.1 and t 47 ± 0.5 ^o C for 65 minutes For chemical sensitization, 100 ml / L of 0.01 N sodium thiosulfate solution and 20 ml / L of a 0.08% solution of hydrochloric acid are introduced. At the end of chemical sensitization, 20 ml / l of a 1% solution of 5-methyl-7-hydroxy-1,3,4-triazaindolycin is administered. Then the pAg was adjusted to 8.6 ± 0.1 and dye 1 was added in an amount of 3.5 • 10 ^-4 mol / mol of silver.

 After 30 minutes of aging, irrigation additives are added and after 15 minutes they are watered on a flexible or glass substrate.

 The photographic characteristics of the holographic material containing the emulsion obtained are shown in the table.

 Example 3

An emulsion with a microcrystal size of silver halide 0.07 μm is prepared analogously to example 2, except that physical maturation is carried out at 45 ^o C and after chemical sensitization additional compound II is introduced in an amount of 10 ^-3 mol / mol of silver.

 The photographic characteristics of the holographic material containing the emulsion obtained are shown in the table.

 Example 4

The emulsion is prepared analogously to example 2, except that after chemical sensitization, compound II is additionally added in an amount of 3 • 10 ^-3 mol / mol of silver.

 The photographic characteristics of the holographic material containing the emulsion obtained are shown in the table.

 Example 5

The emulsion is prepared analogously to example 3, except that after chemical sensitization, compound II is additionally added to the emulsion in an amount of 10 ^-3 mol / mol of silver and compound I in an amount of 2.5 • 10 ^-4 mol / mol of silver with pAg 8, 8.

 The photographic characteristics of the holographic material containing the emulsion obtained are shown in the table.

 Example 6

The emulsion is prepared analogously to example 2, except that after chemical sensitization, additional II is added to the emulsion in an amount of 3 • 10 ^-3 mol / mol of silver and compound I in an amount of 2.5 • 10 ^-4 mol / mol of silver with pAg 8.7.

 The photographic characteristics of the holographic material containing the emulsion obtained are shown in the table.

 From the table it follows that the proposed method of sensitization of silver halide photographic emulsion allows to obtain holographic material, the sensitivity of which when exposed in a pulsed mode is 2 times higher than the sensitivity of the prototype, and the optical density of the veil and the diffraction efficiency of phase holograms are practically unchanged.

Claims (1)

A method of manufacturing silver bromide-silver photographic emulsion by emulsification, gelation, washing, chemical maturation in the presence of sodium thiosulfate and hydrochloric acid, optical sensitization with 3-ethyl-3'-γ-sulfopropyl-4-keto-4'-phenyl-5- sodium salt ( 1 '' - γ-sulfopropyl dihydroquinololidide-4 '' - ethylidene) - thiazolin-thiazolocyanine betaine, characterized in that, in order to increase photosensitivity to pulsed radiation with λ _max = 694 nm, the emulsification is carried out by the method of two-jet controlled crystallization to obtain microcrystals with

μm, after washing, physical maturation is carried out at a pAg of 8.6 ± 0.1 and a temperature of 45 47 ^o C to obtain microcrystals with

before the introduction of the optical sensitizer in the amount of (2.5 3.5) • 10 ^{- 4} mol / mol of silver, pAg is adjusted to 8.6 to 8.8, and after the sensitizer is introduced into the emulsion, 2-heptyl-5-methyl-7- is additionally introduced hydroxy-1,2,4-triazindolycin in an amount of (1 3) • 10 ^{- 4} mol / mol of silver.

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