DE1199612B - Process for stabilizing photographic silver halide emulsions - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

G03c

German class: 57 b -8/02

Number: 1199 612

File number: A 45411IX a / 57 b

Filing date: March 5, 1964

Opening day: August 26, 1965

The invention relates to a process for stabilizing photographic silver halide emulsions by adding suitable stabilizers.

Halogen silver emulsions produced by conventional processes show up on storage in the unexposed Condition, especially in tropical conditions, a sharp decrease in sensitivity, a flattening of gradation and increased fog. As are the susceptibility seeds even the latent image nuclei of exposed silver halide emulsions are not stable on storage. the Stabilization of the latent image is of particular importance in multilayer color photography because the various additives in the individual layers, such as color components, sensitizers, etc., too cause a different change in the latent image nuclei during storage and the color ratio is shifted thereby.

It is known to use halosiber photographic emulsions with hydrazinium salts or hydrazine compounds to be added, as in German patent specification 232 639, in USA patents 2,419,974, 2,419,975, British Patent Specification 598 106 and German Auslegeschrift 1,155,326.

Disadvantages of the hydrazine compounds listed in these patents are that the The above-mentioned effect, namely the stabilization of the photographic layer not at all or only to a small extent Degree is achieved and in addition many hydrazine compounds harden the gelatin have an unfavorable influence or completely prevent it from common hardening agents or if stored in a warm, humid place cause a thick haze.

It has now been found that a stabilization of the latent image nuclei and the so-called Sensitivity nuclei of the customary chemically ripened silver halide emulsions, which on exposure mainly latent image nuclei form on the surface of the silver halide grain, even during storage under extreme conditions, such as wet storage under tropical conditions, can thereby achieve, that the photographic emulsions or a layer in contact with them phenylhydrazides aliphatic, saturated or unsaturated mono- or polycarboxylic acids added. These connections are characterized in that they contain the following grouping one or more times:

- CO —NH-NH-

herein the phenyl nucleus can be arbitrarily substituted by such

Process for stabilizing photographic
Halogen silver emulsions

Applicant:

Agfa Aktiengesellschaft, Leverkusen

Named as _inventors:

Dr. Hans Ludwig Honig, Leverkusen;
Dr. Günter KoIb,

Dr. Franz Moll, Cologne-Stammheim;
Dr. Bernhard Morcher, Leverkusen

Groups that are photographically inactive. These preferably include alkyl radicals up to 5 carbon atoms, alkoxy, preferably of the same type as the alkyl radicals, halogens such as chlorine or Bromine or carboxyl groups,.

The grouping given in the above formula is straight-chain or branched, saturated or unsaturated aliphatic radicals bound.

The following are useful compounds:

Acetic acid phenylhydrazide,

Acetic acid p-tolylhydrazide,

Propionic acid phenylhydrazide,

Butyric acid phenylhydrazide,

Methacrylic acid phenylhydrazide,

Isobutyric acid phenylhydrazide,

Maleic acid-bis-phenylhydrazide,

Fumaric acid-bis-phenylhydrazide,

Itaconic acid-bis-phenylhydrazide,

Glutaric acid-bis-phenylhydrazide,

Citric acid-tris-phenylhydrazide,

Polymethacrylic acid phenylhydrazide,

Adipic acid-bis-phenylhydrazide.

The substances can be added at any point in time of the photographic emulsion or at any time Auxiliary layers are added. The addition is preferably carried out in dissolved form before casting on the substrate.

Surprisingly, it has been shown that while maintaining all the usual photographic properties, which of course largely from that

509 658/443

Structure of the halogen silver emulsion can be determined, in addition an excellent stabilization of the latent image nuclei and the sensitivity nuclei occurs and that even when the after photographic materials produced by the process according to the invention over a very long period of time at normal temperature or when stored in a heating cabinet, even under tropical conditions, d. H. in the case of extremely high humidity, no adverse changes have taken place.

In order to achieve the effect indicated above, the compounds according to the invention are the Emulsions in amounts of 0.1 to 20 g per mole of halosilver, preferably in amounts of 1 to 10 g per mole of halogen silver. The compounds can also be added to auxiliary and intermediate layers will.

The compounds according to the invention, their preparation in a simple manner by known processes is possible, can in principle be used for all halogen silver emulsions. The emulsions can be produced by known methods. These are washed to remove soluble salts and digested to maximum sensitivity. To generate increased sensitivity you can the emulsion sulfur sensitizers, such as. B. thiosulfate, thiourea, or reducing agents, such as. B. Tin salts as well as ammonium, sulfonium and phosphonium salts, and also precious metals such as gold, Palladium, ruthenium, rhodium and iridium can be added. The emulsions can also the usual additives such as plasticizers, hardeners, wetting agents and color-forming compounds. The usual anti-fog stabilizers can also be used, such as. B. tetrazoles, Triazoles, azaindenes, mercapto compounds and mercury compounds.

Silver chloride, silver bromide or mixtures thereof can be used as silver halides, also in small amounts Amounts of silver iodide can be used. For the method according to the invention those halosilver emulsions are used which have been chemically ripened in the usual way, so that the latent image upon exposure formed essentially on the surface of the silver halide grains will. This also differs from the emulsions used in the present process according to the earlier German patent 1,167,655 used emulsions. There will be different Hydrazine derivatives added to direct positive emulsions to improve the color density of the images. With these Direct positive emulsions are silver halide emulsions that mainly contain latent internal grain images form within the individual silver halide grains.

The usual hydrophilic binders are suitable for the photosensitive layer, such as carboxylmethyl cellulose, Polyvinyl alcohol, vinyl pyrrolidone, alginic acid and its salts, esters or amides or especially gelatin.

example 1

A highly sensitive bromine-iodine-silver gelatin emulsion with an iodide content of 4 mol percent and a silver nitrate gelatin ratio of 1: 1 is prepared in the usual way, washed and under Use of sulfur and gold sensitizers matured to maximum sensitivity.

The pH of the finished emulsion is 6.4. Before potting on one of the usual photographic Underlays are the usual stabilizers, wetting agents and hardening agents for the emulsion added.

The emulsion is divided and the individual parts are further processed as follows:

Part A potted without further addition while

Part B 1.7 g acetic acid phenylhydrazide per mole of halosilver,

Part C 3.4 g of acetic acid phenylhydrazide per mole of halosilver,

Part D 1.7 g of isobutyric acid phenylhydrazide per mole of halosilver,

Part E 3.4 g of isobutyric acid phenylhydrazide per mole of halosilver,

^ao Part F 6.8 g of isobutyric acid phenylhydrazide per mole of halosilver

be added in aqueous or methanolic solution before pouring. The finished films contain about 7 grams of silver per square meter. After storage in the tropical cabinet, the films are exposed and developed in a developer with the following composition for 6 minutes at 20 ^° C.:

N-methyl-p-aminophenolsulfonate ... 3.5 g

Sodium sulphate, sicc 60 g

Hydroquinone 9 g

Soda, sicc. 40 g

Potassium bromide, 3.5 g

ad 1000 ml.

The properties of the stored films are in the following table with those of the fresh state exposed samples compared:

Table 1

Receive veil Gra 85 »/, 'Days 35 ° C, Gra find- there Receive relative humidity there High- 0.10 tion find- tion speed 0.09 1.7 lightly- 1.45 100 0.09 1.7 speed veil 1.6 100 0.09 1.7 50 1.7 Part A.. 100 0.09 1.7 75 0.13 1.6 50 Part B .. 100 0.09 1.8 83 0.09 1.8 Part C. 100 1.8 75 0.09 1.8 Part D .. 100 83 0.09 Part E .. 83 0.09 Part F .. 0.09

The melting point of the layer is the same for all samples

over 100 ⁰ C. As the curing agent mucohalic acid was used. As can be seen from the table, the substances according to the invention largely prevent the decrease in sensitivity and the flattening of the gradation when stored in a warm, humid place.

The formation of fog is also favorably influenced.

Example 2

A halosilver gelatin emulsion was made before pouring with 0.3 g of mucochloric acid per kilogram Emulsion and 3.4 g per mole of halosilver of the hydrazine compound listed below

offset. After potting, drying and storage for 48 hours, the melting point of the layer became measured. The results are shown in Table 2:

Table 2

without addition Added substance _ / CH-CH ₃ Melting point
the emulsion 1 CH ₃ - CO - NH- CH ₃ over 100 ° C CH ₃ -CH- NH- CH ₂ - ^ jy 2 < CH ₃ CO- NH ₂ over 100 ° C CH ₃ -CH- <JL> CH ₃ CO- NH- CH ₃ -CH-
I. 1Γ> CH ₃ CO- NH- CH ₃ -CH- CH _S CO- NH- 3 ■ CH ₃ -CH-
I. 32 ° C CH ₃ CO- N = <( CH ₃ - CH - CH ₃ CO- -NH- -NH- -NH- -NH- -NH- -NH- -NH-

While the phenyl-substituted carboxylic acid hydrazides according to the invention listed under 2 do not Hydrazides with a free NHg group, alkyl, cycloalkyl and aralkyl-substituted ones prevent adverse effects Hydrazides as well as acylhydrazones harden the gelatin. The connection types listed under 3 are therefore not usable as additions.

Example 3

A number of hydrazine compounds, compared by the phenylhydrazides of the invention,

the addition of which does not affect the hardening of the gelatine. 5 ° Mucochloric acid was used as the hardening agent,

is prevented, the emulsion was, as in Example i. In all samples, the melting point of the layer was

described, added and their effectiveness with over 10O ⁰ C.

Without addition lot Emp "Frterfi Gra
dation After 7 days, 35 ° C veil Gra
dation CH ₃ -CO-NH-NH- ^ 'S j sensitive
speed 1.7 relative humidity 0.13 1.4 Added substance CH ₃ -CH-CO-NH-NH- ^ N j gpro
MoIAg 100 1.7
1.7 Emp 0.09
0.09 1.6
1.7 CH ₃ - 100
100 veil 1.8
1.8 sensitive
speed 0.09
0.09 1.8
1.8 1.7
3.4 100
100 0.10 50 1.7
3.4 0.09
0.09 75
83 0.09
0.09 75
83

continuation

Added substance NH- < NH-> Θ C10 ₄ © ί CH ₃ CH ₃ © Θ lot
gpro
JVlolAg Emp
sensitive
speed Fresh
veil Gra
dation Nacl
relat
Emp
sensitive
speed 17 days, Ξ
ive Feuchti
veil 5 ⁰ C
opportunity
Gra
dation JH- ^ ^] CP J j
H ₂ N - N - (CHa) ₄ - N - NH ₂ 2 ClO ₄ Q { 1.7
3.4 100
100 0.11
0.11 1.6
1.4 50
50 0.13
0.15 / V-CO-NH— ι CH ₃ CE 1.7
3.4 100
100 0.09
0.09 1.8
1.8 50
66 0.12
0.12 1.45
1.3 C ₂ H ₅ O-CO-NH-NH- / \ { 1.7
3.4 100
100 0.10
0.10 1.4
1.5 50
42 0.13
0.13 1.8
1.8 H ₂ N - CO - NH - NH- ^ S j 1.7
3.4 100
100 0.10
0.10 1.9
1.7 50
50 0.13
0.11 1.25
1.4 C ₃ H ₇ -CO-NH-NH-CO-C ₃ H ₇ j 1.7
3.4 100
100 0.09
0.10 1.8
1.8 50
50 0.13
0.13 1.8
1.8 , CH ₃
CH ₃ -CO -NH-n ("j
CH ₃ ^l
/ \ / 1.7
3.4 100
100 0.08
0.08 1.8
1.8 50
66 0.12
0.12 1.7
1.7 CH ₃ -CO - NH-N '/ ^ = CI 1.7
3.4 200 0.80
stronger
veil 0.8 black
black U
1.7 - f <C © N-CHa-CO— 1.7
3.4 100
100 0.10
0.11 1.5
1.5 black
black - CH ₃ H ₂ NN-CH ₂ -CH ₃ 1.7
3.4 100
117 0.13
0.13 1.6
1.7 black
black - CH ₃ -

Example 4

It is a multi-layer color film, consisting of three bromide silver layers, which acts as a yellow coupler 3- (p-Stearylaminobenzoyl-acetamino) -isophthalic acid, as purple coupler 1 - (3 '- SuIf ο -4' -phenoxy) -phenyl-3-heptadecyl-pyrazolone- (5) and, as the cyan coupler, 1-hydroxy-2-naphthoic acid [2'- (methyl-n-octadecylamino) -5'-sulfonic acid] anilide contains, manufactured. Besides these couplers, the three layers are the usual ones Casting additives, as described in G1 a f k i d e s, Photographic Chemistry, Vol. 2 (Fountain Press London), pp. 564 to 568, for color reversal films are added (FiImI).

A second multilayer film is made in the same way, but this film is made before the Pouring the upper layer of the emulsion containing the yellow coupler per kilogram of 100 ml of one 1% aqueous solution of acetic acid phenylhydrazide was added (film II).

Both films are exposed behind a gray step wedge 50 and stored for 8 weeks at about 20 ° C. and a relative humidity of about 65%. After this storage time, two further samples of both films are exposed under the same conditions. The exposed samples are then subjected to reverse development. The development takes place in baths with the usual composition for reversal films (recipes and processing times in Glafkides, Photographic Chemistry, Vol. 2, pp. 631, 632).
60

FiImI

Film II ....

Exposed and instant
developed

sensitivity

Color cast

100
100

neutral
neutral

Exposed and developed after 8 weeks

Sens.

chance color cast

50 85

yellow neutral

Claims (3)

Patent claims: 1. Process for stabilizing the susceptibility nuclei and the latent image nuclei in exposed silver halide emulsion layers with such Halosilver emulsions which have been prepared in the usual way and which are predominantly latent Forms image nuclei on the surface of the grain, with normal storage and warm, moist storage, characterized in that one of the photographic emulsion or one with it layer in contact with phenylhydrazides of aliphatic mono- or polycarboxylic acids. 2. The method according to claim 1, characterized in that the graphic emulsion 10 Phenylhydrazides of aliphatic carboxylic acids of the formula R-CO-NH-NH wherein R is a straight or branched, saturated or unsaturated hydrocarbon chain with preferably 1 to 6 carbon atoms and the phenyl ring can be substituted, clogs. 3. The method according to claim 1, characterized in that acetic acid phenylhydrazide is added. Legacy Patents Considered:
German Patent No. 1 167 655. 509 658/443 8.65 ® Bundesdruckerei Berlin