DE1294189B - Photographic recording material stabilized against fogging and photographic developer with an antifoggant - Google Patents

Description

1 2

The invention relates to an anti-fog before, during or after the addition of a soluble Formation of stabilized photographic recording silver salt into a soluble halide in raw material with a type of soluble binder applied to a layer support, applied silver halide emulsion layer and such. B. Gelantie, polyvinyl acetate, polyvinyl pyrolidone, a photographic developer with an anti-solubilized casein or egg white, fogging agent. The type of photographic to be stabilized

It is known that preventing excessive recording material is not critical. As Fogging in silver halide emulsion layers Numerous stabilizers or antifoggants have an effect Antifoggants and stabilizers for compounds according to the invention can be used with the. Such fog is produced in a variety of different photographic silver halide ways caused, e.g. B. by prolonged maturation of the emulsions, such. B. non-sensitized, ortho emulsions during storage of the film or chromatic, panchromatic silver halide paper, especially at elevated temperature and emulsions, X-ray emulsions, paper emulsions Moisture, or when using chemical and paint emulsions. You can Sensitizers, especially alkylene oxide derivatives, also in combination with other known anti-(USA. Patents 2704716, 2 716 062 and lubricants and stabilizers or in connection 2 728 666). Too long a development can also use sulfur, reducing, metal and precious metals Cause fogging. sensitizers or with polyoxyalkylene and their

By using antifoggants it is possible to use derivatives.

it is now to avoid increased fogging and 20 The concentration of the inventions used Storage properties of the photographic com- pounds depend on the nature of the to To improve drawing material. stabilizing silver halide emulsion and can

It is now desirable to vary the stabilization effects over a wide range. You will be at sarakeit of known antifoggants to additive during ripening or sensitization and the Beas level observed in some cases, expediently at a concentration of 0.02 Impairment of the photosensitivity of the photo to 5 mg per 0.6 mol of silver halide and when added graphic recording material by the anti-before the application of the silver halide emulsion to switch off the fogging agent. Furthermore, the should often to the support in a concentration of 1 to Observational impairment of the sensitization - 20 mg per 0.6MoI silver halide used. In The effect of the added coloring agents is eliminated in many cases, the greatest stabilizing effect is achieved will. achieved when the stabilizers or anti-fog

The object of the invention is to create an anti-fogging agent in a surface layer of gelatin stabilized photographic editions.

By stabilizing the drawing material, the invention achieves that the stabili-

Fogging in extremely efficient photographic recording materials Manner, with no reduction in less post-development fogging the photosensitivity of the photographic storage and, if necessary, subsequent storage Drawing material, but in most cases have higher temperatures than when used even an increase in it occurs and no known antifoggants. With the influence of the invention the effect of sensitizing dye stabilization is not a reduction in the substances takes place. Another object of the invention is the photosensitivity of the photographic record Creation of a photographic developer, associated with processing material, but instead it occurs in the by applying the advantages just mentioned, in most cases even an increase in the same. also occur. Furthermore, there is no influence on the effect of

The subject matter of the invention is one versus 45 sensitizing dyes. The invention Show fogging stabilized photographic recording materials Drawing material with one on a layer support in addition when using certain light temp Silver halide emulsion layer composed of sensitive layers is a particularly attractive one and is characterized in that there is a warming image tone, especially when the setting of the formula 50 trains are dried at a relatively high temperature. • ή Another object of the invention is based on

a photographic developer comprising an antifoggant characterized by that he is a compound of the formula

R'SH "

55 _R

contains, in which R is a methyl, ethyl, mercaptomethyl; i

or a mercaptoethyl group and R 'is -! -R'SH

Methyl or ethyl group, where R 'is the same 60
Has number of carbon atoms like R.

The compounds according to the invention can contain in the R a methyl, ethyl, mercapto

the preparation of the silver halide emulsion, while methyl or mercaptoethyl group and R '

their maturation or sensitization stage or un- a methyl or ethyl group, where R 'in each case the

indirectly before the application of this silver halide 65 has the same number of carbon atoms as R.

emulsion on a conventional support, such as. B. In this embodiment too, the

one made of glass, paper or plastic film, the same advantages as those already mentioned are achieved

be incorporated. In the first case, the addition can occur when the compound of the invention the

to be stabilized photographic recording material is incorporated in the manner described. In both embodiments of the invention,, - dimercapto-p-xylene is particularly preferred as a stabilizer or as an antifoggant. Furthermore,-mercapto-p-xylene and ß, ß'- dimercapto-p-diethylbenzene are particularly notable as stabilizers contained in the layer. Further compounds suitable according to the invention as stabilizers or as antifoggants are the following:

1. «,« '- Dimercapto-m-xylene,

2. «,« '- Dimercapto-o-xylene,

3. «-Mercapto-m-xylene,

4. "-Mercapto-o-xylene,

5. /J./J'-Dimercapto-m-diethylbenzene,

6. / ί, / ί'-Dimercapto-o-diethylbenzene,

7. / J-mercapto-p-diethylbenzene,

8. ß-Mercapto-m-diethylbenzene or

9. β-mercapto-o-diethylbenzene.

The following results were obtained:

Most of the stabilizers or antifoggants used according to the invention are already known and their production processes have been described in the literature. According to the information in Ber., 42, p. 4349 (1909), z. B. χ, oif - Dimercapto - ρ - xylene, «,« '- Dimercapto - ο - xylene and «, a'-Dimercapto-m-xylene from an alcoholic potassium hydroxide solution by the action of hydrogen sulfide until saturation and reaction with a solution of corresponding xylene bromide compound in 95% alcohol by volume. The α-mercaptoxylenes can be prepared in the same way, but only one equivalent of potassium hydrogen sulfide is used. In the production of the corresponding diethylbenzene derivatives, the xylene bromide is replaced by diethylbenzene.

The following examples serve to illustrate the invention:

example 1

Using silver bromide and silver iodide (98: 2 mole percent) as silver halides and With gelatin as a binder, a silver halide emulsion was prepared and tested for its maximum light sensitivity brought. Then it was prepared for application to the substrate and additives, such as sensitizing dyes and hardening agents are added. A 0.01 weight percent solution of «,« '- Dimercapto-p-xylene in methanol became the Emulsion also added.

The silver halide emulsion sample contained about 0.6 moles of silver halide. After applying of the samples on a cellulose ester support, these were dried in a sensitometer exposed and developed in a developer of the following composition:

p-methylaminophenol sulfate 1.5 g

Sodium sulfite (anhydrous) 45 g

Sodium bisulfite Ig

Hydroquinone 3 g

Sodium carbonate (monohydrate) 6 g

Potassium bromide 0.8

topped up with water to 11

Amount of
used
Stabilizer Relative
Sensation
opportunity Veil at
12 minutes
development Furnace veil *)
at 6 minutes
development 0
lmg
2 mg
5 mg 100
100
100
90 0.28
0.25
0.20
0.20 0.22
0.21
0.15
0.14

*) The samples in the oven 3 days were kept at a furnace temperature of 6O ⁰ C and a humidity of 50% long.

Example 2

Example 1 was repeated, but instead of the ρ-xylene derivative ß, ß'-dimercapto-ρ-diethylbenzene was used. The results were practically the same.

Example 3

Exposed samples of a photographic material were developed in a developer specified in Example 1 ^{at 18 ° C. for 12 minutes.} Two tests were carried out, one of which was carried out with a developer containing 4 mg ",""- dimercapto-p-xylene per liter of developer solution. The stripes developed in normal developer (control) for 12 minutes had a haze of 0.30 while the stripes developed in the developer with antifoggant had a haze of 0.18. The relative sensitivity of the photographic material showed the same value as that of the unstabilized material, namely 100.

Example 4

Using silver bromide and silver iodide (98: 2 mole percent) as silver halides and With gelatin as a binder, a silver halide emulsion was prepared and coated on a film support. An aqueous gelatin solution containing 20 g of gelatin in 1 liter of water and 8 mg of "," - dimercapto-p-xylene contained, applied to it as an abrasion-resistant layer. After drying, samples of the photosensitive material such as exposed and treated in Example 1. The samples showed a relative sensitivity of 100 and a fog of 0.18, while one layer of the above silver halide emulsion and one abrasion resistant making layer containing no antifoggant had a haze of 0.30.

Example 5

Example 1 was repeated, except that the p-xylene derivative was replaced by an equivalent amount of a-mercapto-p-xylene was replaced. The same results were obtained.

Example 6

Example 4 was repeated, except that the p-xylene derivative was replaced by an equivalent amount of / S-mercapto-m-diethylbenzene was replaced. Less good results than in Example 4 were obtained.

Claims (4)

Patent claims: 1. Photographic recording material stabilized against fogging and having a silver halide applied to a layer support emulsion layer, characterized in that it is a compound of the formula -R'SH contains, in which R is a methyl, ethyl, mercapto ίο methyl or mercaptoethyl group and R 'is a methyl or ethyl group, where R' each has the same number of carbon atoms like R. 2. Photographic recording material according to claim 1, characterized in that it contains "," - dimercapto - ρ - xylene, "■ - mercapto - ρ - xylene or ßjS'-dimercapto-p-diethylbenzene. 3. A photographic developer with an antifoggant, characterized in that it a compound of the formula X- R'SH contains, in which R is a methyl, ethyl, mercaptomethyl or mercaptoethyl group and R 'is a methyl or ethyl group, R' each having the same number of carbon atoms like R. 4. A photographic developer according to claim 4, characterized in that it contains α, α'-dimercapto-p-xylene contains.