HU202993B - Method for making homodispersion photoemulsion - Google Patents

Abstract

The invention relates to a process for the preparation of a homodisperse photographic silver-halide emulsion by precipitating the crystals at a constant pAg value by means of a regulated, twin outflow and enlarging the crystals to the requisite size, if necessary by removing the ions present in excess, optionally by chemical sensitisation of the crystals and by adding known additives, which is characterised in that crystals having a size of L > 0.180 mu m (in which L is the diameter of a circle having an area equal to the crystal projection) and built up from a central core and at least four shells, each of which has a thickness of from 0.005 to 0.0098 mu m and each have a different composition, where the thickness of the shell structure does not reach the Debye separation, are prepared by a suitable change in the composition of the starting solutions and the amount of silver nitrate or halogen salt.

Description

The present invention relates to a process for the preparation of a multi-shell photographic emulsion comprising homodispersed silica halide crystals.

In the production of silver halide photographic emulsions by conventional single-beam deposition, heterodisperse crystals are formed due to constant variations in the concentration of free halide ions. In this case, the photographic properties depend essentially on the particle size distribution. This is also strongly influenced by changes in technological factors, which impairs the repeatability of the characteristics of the photosensitive material.

The stability of the granulometric properties can be ensured by the special technology for the precipitation of silver halide crystals [E. Moisar - E. Klein: Berichte dér Bunsenges. Phys. Chem., 67, 949 (1963)]. In this method, the crystals are precipitated by a double run at a constant constant value controlled by the free halide ion concentration; then homodisperse particles are formed. Inorganic gelatines (containing only a few parts per million) are usually used for the preparation of such crystals, and the photographic properties are controlled by the use of artificially added anesthetics and inhibitors.

The photographic characteristics can be influenced by so-called. also with crystals having a core / shell structure. [E. Moisar - S. Wagner: Berichte dér Bunsenges. Phys. Chem., 67, 356 and 1,169,290,290 (1963)]. They are made by applying a controlled double flow to a different sized crystal, core, layer, shell, or shells. For example, U.S. Pat. No. 3,935,014 teaches that an AgCl shell is built on an AgBr core, or three Ag (Cl, Br) shells are deposited on a silver bromide core with decreasing chloride content. Alternatively, Ag (Br, I) core is stripped of AgBr (U.S. Patent No. 3,206,313).

The shell thickness varies. If, as in most cases, a shell is located on the central core, the shell is relatively thick; for example, in U.S. Patent No. 3,761,276, 0.2-0.5 nm. For multiple shells, the thickness is 0.1 µm or less than, for example, UK 2,095,853A. in application number 0.01-0.1 µm.

The surface of each shell is chemically sensitizable (U.S. Patent 3,337,322, G. Junkere et al., J. PhoL Sci., 22, 174 (1974)),

During the dual run, the crystals contain either Pb ² * or Cd ² * ions [CR Berry - DC Skillman. Phot. Sci. Eng., 11, 411 (1967)] and other polyvalent ions such as Fe 2+, Ru ³ *, Rh ³ *, Pd ² *, Os ³ *, Irish ³ *, Pt ⁴ * and Bi ³ * which increase the internal sensitivity in direct-positive and reverse emulsions [JW. Mitchell: Phot. Sci. Eng., 27, 81 (1983). The inclusion of iridium, lead, gold, cadmium, zinc and erbium in core / shell structure crystals (U. S. Patent No. 2,101,831).

The object of the present invention is to improve the control of the photographic properties of emulsions.

The present invention is based on the discovery that by forming a plurality of shell structures, each shell having a thickness less than 0.01 μηι, and the entire shell having a thickness less than the Debye distance, the chemical composition of the shell can be arbitrarily controlled in the peripheral layer of the crystal. space charge distribution. This is important because according to recent research [N. Starbov - J. Malinovski: Phot. Sci. Eng., 32, 245 (1984)] is a direct participant in the inter-lattice silver ion process, and its presence is crucial for both neutralizing the already captured electron and increasing the silver centers to an aggregate size that can be recalled. The distribution of the inner latency follows the distribution of the interlattice silver ions in the space charge layer very well, and the probability of capturing and neutralizing the photo-excited electrons in the area below the surface is proportional to the concentration of the interlattice ions in the space charge.

The invention is also based on the discovery that it is desirable to regulate spatial charge distribution primarily by introducing metal ions and iodide ions in various concentrations into the shells.

The invention is also based on the discovery that altering the composition of the shells can significantly influence the surface sensitivity of the crystals.

A further basis of the invention is the discovery that incorporating In ³ * ée / or La ³ * ions into the shell provides a more favorable photographic effect than other metal ions.

The use of In ³ * and La ³ * ions in precipitation is described in Hungarian Patent No. 190,408. However, these ions are present throughout the addition of silver nitrate and are distributed throughout the entire volume of heterodisperse crystals formed.

In the process of the invention, homogeneous silver halide crystals are precipitated and grown to the required size with constant pAg, controlled double flow, excess ions are removed if necessary, the crystals are optionally chemically sensitized, and the emulsion is provided with the necessary additives. , in such a way that the composition of the stock solutions and the silver nitrate and / or silver nitrate, respectively. with suitable variation in the amount of halogen salt, L> 0.180 pm (where L is the diameter of a circle having the same area as the crystal projection) from a central core, and at least

HU 202993 Β Four crystals of different shell thicknesses of 0.005-0.0098 µm each are produced, while the thickness of the shell structure is less than the DEBYE distance.

The process of the invention, at least a shell 10, of all four shell ^'7 -10 * ² mol / mol AgX quantities in ^3-and / or ^3-La ions and a shell comprising at least 10 mole percent, ^_3 -10 in an amount of iodide ions. .

In the process of the present invention, at least one of each of the four shells having no indium, lanthanum or iodide ions in the amount of 10 ⁷ -10 * ² mole / mole AgX, wherein X is halogen, is selected from the group II, III. , IV. or VIII. column item. This can be, for example, Cd ² *, Pb ² *, Ca ² *,

Pd ² *, Be ² *, Mg ² * ion, or Rh ³ *, Y ³ *, Bi ³ *, Irish ³ *, Au ³ *, Os ³ *, Ru ³ * ion, or Irish ⁴ *, Pt ⁴ * and Ce ⁴ * ions.

In the process of the present invention, the crystalline seed comprises AgCl, Ag (Cl, J), Ag (Cl, Br), Ag (Cl, Br, J), AgBr and Ag (Br, J). ).

In the process of the present invention, this emulsion is provided with the usual additives (color sensitizer, stabilizer, tanning, wetting, color-forming, etc.).

Examples of color sensitizers are 1-ethyl-3'-phenyl-2-quino-5'-rhodanine (dye-1), 3,3'-diethyl-1'-phenylbenzoxazolidene (ethylidene-2'-thiohydantoin). (dye-Π),. 3,3'-Diethyl-6,6'-Dinaphthyl-9-phenylthiocarbocyanin (Dye III), Benzothiazol-phenyl-2-methylhydantoin-tetramethinetherocyanine (Dye IV) (P. Glafkides: Photographic Chemistry , Vol. II, pp. 832-856, Fountain Press, London 1960).

Examples of stabilizers that may be used are 4-hydroxy-6-methyl-1,3,3a, 7-tetraazaindole (TAI), 1-phenyl-5-methylcaptotetrazole (FMT), mercaptobenzothiazole (MBT) and the like. . (G. F. Duffin: Photographic Emulsion Chemistry, pp. 138-141, Focal Press, London 1966).

Tanning agents may be, for example, formalin, glyoxal, glutaraldehyde, 2,4-dichloro-6-oxy-s-triazine, etc.) T. H. James, Theory of the Photographic Process, IV. 82, Ed. Mc Millan, New York, 1977).

As the wetting agent, for example, alkenyl succinic polyglycerides, dodecyl phenol polyglycol ether, saponin, and the like. (Der. M. Derjagin - S. M. Levi, Film Coating Theory, p. 162, Focal Press, London, 1966).

Advantages of the process according to the invention are as follows:

1. Smaller crystals give greater sensitivity than conventional emulsion. The layers of the present invention would therefore provide a better coverage, sharper, and finer granularity than those produced with heterodisperse emulsions of the same sensitivity.

2. In indium-ion-containing layers, the same energy content but high intensity and short (10 ^ 10 ^-6 s) illuminations have a lower density reduction than non-indium ions. (Deviation from the Law of Reciprocity, F. EVVA: The Hidden Photographic Image, Akadémiai Kiadó, Budapest, 1980, p. 65).

3. The repeatability of the photographic properties of emulsions can be significantly improved.

The following embodiments illustrate the process of the present invention.

Example 1

For an emulsion containing 200 ml of L = 0.120 µm AgBr crystals (0.209 moles), PBr = 2.5 and -50 ° C with stirring in a double beam. 365 ml of a 4 M solution of AgNO 3 and 365 ml of a 4 M KBr solution were passed over 120 minutes; Crystals of size L = 0.240 µm were obtained.

To 130 ml of this base emulsion is added 770 ml of 5 tX-οβ inert gelatin solution containing 15 pM / M AgX of sodium thiosulphate, the pBr is adjusted to 3.0 and then at 60 ° C for 60 min. maturing.

After maturation, add the usual additives (aliquots of emulsion 80 ml 0.05 tX Color II, 100 ml 50 tX glycerol solution, 20 ml 5 tX formalin, 250 ml 1 M AgX). tX TAI solution, 40 ml 4 tX saponin solution) and then poured onto a paper support (A) with a silver content of 10 ² g / dm ² .

The synthesis is then repeated by growing L = 0.120 µm from the strains under the above conditions, first with L = 0.200 µm, under the influence of 197 ml of 4 m AgNO3 and 197 ml of 4 M KBr solution for 60 minutes, and in four successive portions, 42-42 ml of 4M AgNO3 and KBr solution were introduced into the emulsion over 13-13 minutes such that either AgNOa or KBr solution contained the required additive in the required amount, so that L = 0.238 pm size crystals having four shells each having a thickness of 0.0095 µm. Hereinafter, emulsion (A) (emulsion B-L) is used.

The resulting layers are subjected to a sensitogram exposure to a 2850 K color incandescent lamp for 2 minutes at 18 ° C in the following solution: 1 g of ingot, 20 g of anhydrous sodium sulfite, 4 g of hydroquinone, 10 g of anhydrous sodium carbonate, g potassium bromide - in 1 liter of water.

Table 1 gives information about the additives in the shells and the photographic properties of the layers.

The results show that the photographic properties of the shellless emulsion (A) are not sufficiently stable (incubation ha-35).

EN 202993 Β graduation decreases significantly and the veil formed during higher temperature development). In contrast, layers containing shell-like crystals (especially indium and iodide ions) exhibit a photographic property during incubation. In addition, crystals containing indium ions in multiple shell structures have a higher sensitivity.

Table 1

Emulsion Shell Structure Photographic characteristics

First Second Third 4th Average- gradient Rel. sensitivity dm do 18 °, 2 ' 30 °, 10 ' (THE) - - . - - F 2.20 100 1.80 0:04 0:23 I 1.82 110 1.72 0:05 0:48 (B) In ³ * - - - F 2.60 104 1.85 0:05 . 0:20 • I 2.56 98 1.80 0:06 0:21 (C) In ³ * - i- - F 2.23 115 1.70 0:05 0:20 I 2.07 101 1.80 0:07 0:17 (D) Sat ³ * - - - F 2.30 80 1.85 0:04 0:20 2:20 72 1.80 0:05 0:22 (E) Sat ³ * - i- - F 1.96 110 1.70 0:05 0:28 I 1.94 104 1.84 0:04 0:29 (F) In ³ * - In ³ * - F 2.40 132 1.80 0:05 0:25 I 2.46 122 1.82 0:06 0:27 (G) In ³ * - In ³ * I- F 2.90 110 1.90 0:06 0:25 I 2.82 105 1.86 0:07 0:28 (H) In ³ * - I- i- F 2.66 85 1.80 0:06 0:25 I 2.50 76 1.78 0:06 0:30 (J) In ³ * Cd ² * I- - F 2.30 126 1.75 0:05 0:15 I 2.16 120 1.76 0:05 0:17 (R) In ³ * Rh ³ * I- - F 2.40 119 1.78 0:04 0:16 I 2.30 100 1.80 0:06 0:18 (L) In ³ * - Ru ³ * I- F 2.42 156 1.80 0:06 0:20 I 2.32 142 1.76 0:06 0:25

Note: Additives: indium nitrate, lanthanum chloride, potassium iodide, cadmium bromide, rhodium chloride, ammonium hexachlorotene,

In ³ *, La ³ *, Cd ² * concentration

10- ⁵ mol / mol Rh ³ * ³ * Ru concentration 10 ⁷ mol / mol; iodide ion concentration in shell 3 is 0.5 MX,

In shell 4, 2 MX (H) and 0.1 MX (L)

F = fresh, untreated sample, 1 = 50 ° C after 5 days incubation.

Example 2 45

125 ml of the base emulsion (C) L = 0.240 µm prepared in Example 1 are flocculated, redispersed with 475 ml 7.6 tX inert gelatin solution and the pBr of the emulsion is adjusted to 50 3.00. Sodium thiosulfate (25 μΜ / Μ) and ammonium gold thiocyanate (10 μΜ / Μ) were then added, followed by chemical aging at 60 ° C for 120 minutes. After maturation, the usual additives (see Example 1) are added and then poured onto a triacetate support with a silver content of 2.5.10 x ² g / dm ² . The resulting film is sensitized according to ANSI PH 2.5-1972: 25 ASA sensitivity after 60 min. With the same exposure, Kodak D-II develops a slope of 7 = 4.20 at 7 ° C for 7 minutes. When developed under these conditions, the film has a resolution of 125 lines / mm.

HU 202993 Β

Example 3

To an emulsion containing 200 ml of AgBr octahedron crystals of size L = 0.240 pm (0.316 mol) was added 187 ml of 4 M AgNCb and 187 ml of 4 N KBr solution under stirring at pBr = 2.5 and 50 ° C for 5 minutes in a double beam. . Crystals of L = 0.360 µm are then formed.

150 ml of this emulsion was flocculated, redispersed in 450 ml of 7% inked gelatin solution, the pBr was adjusted to 3.00, then 30 pmol / mol sodium thiosulphate and 12 pmol / mol ammonium gold thiocyanate was added and a chemical aging at 160 ° C for 160 minutes.

At the end of maturation, add the usual additives (to 1 mole of silver halide: 200 ml of 0.1% dye solution IV, 160 ml of 50% glycerol solution, 80 ml of 4 tX) to an aliquot of the emulsion. saponin solution, 40 ml of 5% formalin, 300 ml of 1% TAI).

The emulsion is then loaded on a triacetate carrier with a silver content of 3.5 ¹⁰ g / dm ² (A).

The synthesis is then repeated so that from the starting crystals of size L = 0.240 µm, under the conditions mentioned in (A),

By running 108 ml of 4 M AgNOs and 108 ml of 4 M KBr solution over 36 minutes, L = 0.320 pm was first grown and 20 ml of 4 M AgNO3 and 20 ml of 4 M were prepared in four successive portions for 8 to 8 minutes. The KBr solution is introduced such that either the AgNOs or the KBr solution contains a specified amount of the shell building additive. This gives crystals of size L = 0.356 µm with 4 shells each having a thickness of 0.009 µm. In the following, the procedure is as follows (when making emulsion A, emulsions B-F).

Table 2 shows the quality and quantity of additives incorporated into the shells and the photographic properties of the layers. The latter are described in ANSI PH 2.5-1972. standard with a 5 minute call time.

Emulsion Shell structure treatment Meeting Photographic features 1. 2. 3. 4th Relative sensitivity kenység Average gradient do £ shs (THE) - _ _ F 100 0:58 0:06 12 I 95 0:52 0:08 (B) In ³⁴ - J- - F 130 0.65 0:06 11 I 116 0.63 0:07 (C) Sat ³⁴ - J- - F 110 . (V70 n.ns m I 105 Ό.61 0:05 (D) In ³⁴ - In ³⁴ - F 140 0.62 0:04 10 I 129 0.60 0:05 (E) In ³⁴ - In ³⁴ J- F 146 0.60- 0:08 10 I 150 0:58 0:10 (G) Traditional Ag / Br, J / F 150 0.63 0:08 22 emulsion / ¹ I 130 0.61 0:10 (F) tendon ³⁴ - Ru ³⁴ 1- F 160 0.63 0:07 11 I 150 0.61 0:08

Note: 1 Average diameter d = 0.35 pm, C = 16%

In ³⁴ at 10 * ⁵ mol / mol;

Ru ³⁴ concentration

IO ^- ® mole / mole: iodide content:

0.5 mol% 55

F = fresh, untreated sample,

1 = 50 ° C after 5 days incubation.

The results show that the multi-shell crystals at 60 and the same size give greater sensitivity than the non-shell ones, or, at the same sensitivity, the finer granularity (see 5rms values) than conventional Ag / Br, J / 65 emulsions.

Example 4

An emulsion (pBr = 2.5) of 200 ml of L = 0.360 µm octahedral AgBr crystals (0.387 moles) is stirred at 50 ° C for 60 minutes under 1728 ml of 1.5 M AgNOa solution and 1728 ml of halide solution, 1.47 M for KBr and 0.03 M for KJ. This gives crystals of size L = 0.720 pm.

300 ml of emulsion (44.7 g metal silver content) was flocculated, redispersed in 400 ml of 10% inked gelatin solution, pBr was adjusted to 3.00, then 25 pM / M sodium thiosulfate and 10 pM / M ammonium. aranytio-59

After the addition of HU 202993 ian, cyanate was aged at 54 ° C for 150 minutes.

After maturation, the following additives are added to an aliquot of the emulsion, to 1 mole of silver halide: 120 ml of 50% glycerol solution, 85 ml of 4% saponin solution, 40 ml of 5% formalin, 320 ml of 1 t % TAI solution. The emulsion is then applied to a triacetate carrier with a silver content of 3.5 g / m ² per side. (THE)

The synthesis is then repeated by first growing L = 0.663 µm crystals of emulsion (A) with 1297 m of 1.5 M AgNOs solution and 1297 ml of halide solution (1.47 M for KBr, 0 for KJ). (3 M) over a period of 43 minutes followed by six successive portions of 72-72 mL of 1.5 M AgNO3 and 1.5 M

A KBr solution is introduced over 2.5-2.5 minutes so that the AgNO3 or KBr solution contains the required amount of shell building additive, so that L = 0.720p crystals of 6 shells each are obtained. 0095 pm (BD emulsions). Hereinafter, we will proceed as in the preparation of emulsion (A).

The quality and quantity of additives incorporated in the shells and the photographic properties of the layers are illustrated in Table 3. Sensitograms were obtained using ANSI PH 2.5-1972. standard (hanging Ho = 0.087) and then developed in an Agfa-30 developer at 20 ° C for 5 minutes. Sensitivity was calculated using the formula S = 0.8 / Hk, where Ά is the illumination needed to create the Dk = Do + + 0.1 density criterion.

Table 3

Emulsion Shell structure 6th Treatment í S do Daax First 2.3. 4th 5th (THE) - - - - - F 1.95 80 0.Ό8 2:46 I 1:46 88 0:15 2:36 (B) In ³ * In ³ * - J- - F. 2:18 150 0:10 2.63 I 2:10. 146 0:11 2.60 (C) In ³ * In ³ * J- J- - F 2:02 168 0:12 2:56 I 1.96 160 0:12 2:54 (D) In ³ * In ³ * • J- J- J- F 1.80 193 .0.16 2:40 I 1.76 195 0:18 2:42

Note: In ³ * dosing 10 ⁵ M / M, iodide content in emulsion (B) 0.6% w / w, emulsion (C) 2% w / w in shell 4, 1% w / w in (D) 2, 1 and 0.2%, respectively.

Do without substrate means F and I as above

The results show that the sensitivity of the layers containing the shell-structured crystals is significantly increased while the gamma value is only slightly decreased.

Claims (4)

1. A process for producing a homodisperse silver halide photographic emulsion by precipitating crystals at constant pAg in a controlled dual path and L> 180 nm - where L is the diameter of a circle having the same area as the crystal projection. - increasing the ions, flocculating excess ions or other known methods, if necessary, chemically sensitizing the crystals and adding known additives for casting, such as color sensitizers, plasticizers, wetting agents, tanning agents, stabilizers, characterized in that generating in known manner a larger core than 0.180 pm, and then applied to the shell thickness to the core, at least four, each of 0.005 to 0.0098 nm, such that each of the four shells 20 at least one shell 10 ^'7-10 M per mole of AgX - wherein X is halogen. - In ³ * and / or La ³ * ions, and in at least one shell 10 ³ to 10 moleX of iodide ions are introduced into 25 and at least one of every four shells containing no indium, lanthene or iodide ions, ⁷ to 10 * ² moles / mole of AgX, wherein X is halogen, is used in the periodic renderer II. 30 or VIII. is inserted until the thickness of the shell structure reaches the DEBYE distance. (Priority: July 16, 1986) 2. A process for preparing homodisperse silver halide 35 photographic emulsion by controlled crystal precipitation of crystals at constant pAg and Increasing the size to L > 180 µm, where L is the diameter of a circle having the same area as the projection area of the crystal, flocculating excess ions, or removing any crystals as required by other known methods. chemical sensitization and addition of known additives for casting, such as color sensitizers, plasticizers, wetting agents, tanning agents, stabilizers, characterized in that it produces in a known manner at least four seeds, each of 0.005-0.0098 µm per core. applying a thickness of a shell such that at least one of each of the four shells contains 10 ~ ⁷ to 10 mol / mole of AgX - wherein X is halogen - In ³ * and / or La ³ * ions, b in at least one shell ΙΟ ^-3 - 10 mol% of iodide ions are added and at least one of each of the four • shells is free of indium, lanthanum or iodide ions, ΙΟ ⁷ to 10 * ² mol / mol AgX - where X is halogen - a Periodic Table II, III, IV, or VIII. is inserted until the thickness of the shell structure reaches the DEBYE distance. (Priority: 14.04.1987) The process of claim 1, wherein the crystal core is selected from the group consisting of AgCl, Ag (Cl, J), Ag (Cl, Br), Ag (Cl, Br, J), Ag and Ag (Br, J). (Priority: July 16, 1986) The process of claim 1, wherein the crystal core is of AgCl, Ag (Cl, J), Ag (Cl, 'Br), Ag (Cl, Br, J), AgBr and Ag (Br, J). (Priority: 14.04.1987)