DE2021518A1 - Photographic bleach and bleach-fix baths - Google Patents

Description

AG FA- G EVAE RT AG ^mi518

za-mka Leverkusen

Photographic oils bleaching and bleaching baths

The invention relates to photographic processes for the development of multi-layer color materials on halogen silver bases, bleach baths used in particular in the "processing" Bleaching developed silver with complex ferric salts as Oxidizing agent.

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It is known to use bleaching solutions to stabilize them against pH fluctuations Add buffer substances. Buffering in the range from approx. PH = 4 to 7, in particular, is of interest 5 - 6.5, Compliance with these tolerances is important in order to on the one hand that which occurs more intensely above pH = 6.5 Formation of color haze, on the other hand the rapidly increasing decomposition of the bleach below pH = 5.0, in the case of ferricyanide with separation of Prussian blue, to be held back. Commonly introduced for this purpose are acidic phosphates alone or in combination with glacial acetic acid, boric acid or citric acid and their salts.

109849/1477

The disadvantages of these buffer substances are, in part, only minor ones Buffer effect in the desired pH range, but in particular its effect on hardening and swelling behavior with inorganic ones Hardening agents (chromium or aluminum salts) of pretreated films. In particular, that for buffering at approx. pH = 6, indispensable phosphate, has a negative effect on layer adhesion and the development of wrinkled grains that has not yet been recognized enough in processing baths or washes following the bleach bath. Another disadvantage of phosphate-buffered baths is that neither preceding stop or clarifying baths nor subsequent fixing baths may contain inorganic hardeners, α if for reasons of time or water savings on extensive Intermediate washes should be avoided.

The invention is based on the object of creating new buffer substances to find,

which buffer in the range from pH 5.0 to pH 6.5 or above, which are not soluble in salts with trivalent metal ions (Avoidance of the precipitation of inorganic hardeners), which have no or only weak complexing effect Cr ■ and Al ions (avoiding the reversal of Layer hardening) and which are resistant to the oxidizing agent in the bleach bath are.

There has now been made a method of making color photographic Images by negative or reversal processing, found with one exposed, at least one silver halide emulsion layer -photographic material containing color developed and then is bleached and fixed, the bleaching in the presence of an aliphatic dicarboxylic acid of the following formula is carried out:

R ₁ - ^R 3
HOOC - (0Η ₂ ) _{£ ΓΓ} - C - (CH ₂ ) ^ ₁₁ - C- (CH ₂ ) Pi COOH

^R 2 ^R 4

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in which mean

R ₁ , R ₂ , R, or R. = ■ hydrogen, alkyl with up to 5 carbon atoms, ■ _: · ■ - preferably methyl or ethyl $ where R ... to R. are of course the same

, ea. "." ".." ■ or can have different meanings;

n, m "or ρ = 1 - 5 with the condition that the sum

of the indices does not exceed 7.

The following compounds, for example, are particularly suitable:

Succinic acid, g-lutaric acid, adipic acid, methyl-ethyl-malonic acid, Diethylmalonic acid, 2,2,4-trimethyladipic acid, etc.

All soluble, neutral and acidic salts with Λ alkali metal ions and ammonium ions can be used as salts. '

The choice of the best connection in each case depends on the desired area to be optimally buffered, i.e. the solubility ' the acid or the salt at the respective pH value, the permissible or desired complex-forming ability and of course the economy of the substances with which the desired Effect can be achieved. Of particular interest are adipic acid and its salts, such as succinic acid, where Adipic acid is particularly suitable for solutions above pH = 5, while succinic acid can be used with advantage in more acidic solutions, in which the solubility of adipic acid is no longer sufficient. Alkyl-substituted dicarboxylic acids come - as a result of | Decrease in the dissociation constants, in particular due to substituents in the X position to the carboxyl - for at higher pH buffering baths in question. While e.g. malonic acid in the areas pH = 1.8 - 3.2 and approx. 4.5 - 6.0 optimally buffers, shift the buffer ranges for diethylmalonic acid according to pH = 1.8 - 3.6 and 6.25 - 7.9 »it therefore represents an optimal one Buffers for the neutral point. The values of methyl-ethylmalonic acid lie between those of the two compounds mentioned. ·.

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The extraordinarily beneficial effect of the in the invention Substances to be used wisely is therefore special Surprising because very similar compounds, e.g. malonic acid, differ only slightly in their buffering effect from the longer-chain ones or substituted dicarboxylic acids, in contrast to these similar to phosphate or phosphate-acetic acid buffers causes the emulsion layers to swell or even become detached. So it is approaching in its properties the very unfavorable citric acid, which would be well suited because of its wide buffer range.

The substances to be used in the manner according to the invention can be used in amounts up to the limit of solubility, however, preferably up to about 30 g / l, are added.

The bleach baths according to the invention can contain, for example, the following as oxidizing agents in amounts of 20 to about 200 g / l: lithium, sodium, potassium salts of Fe complexes with hydrocyanic or ethylenediaminetetraacetic acid and similar compounds .

Further additives are all substances commonly used in bleaching solutions, such as bromides, complexing agents for silver halides (Fixative) and anti-limescale agents such as ethylenediaminetetraacetic acid or derivatives thereof, nitrilotriacetic acid etc. as well as additional buffering agents such as acetates and boric acid or borax, bleach accelerators and corrosion protection agents of an organic or inorganic type, e.g. alkali metal or ammonium dichromates are suitable. The amount of these substances depends on the desired effect.

Of particular interest is the addition of substances that contain aluminum salt carried over from previous hardening baths keep complex in solution even in larger quantities and at pH values around or above pH = 6. Above all, there are to be mentioned Sodium acetate in quantities of 1-50 g / l and trisodium citrate

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in amounts of "0.5 - 30 g / l, but preferably of 0.5 '■ -' 5.0 g / l. 'By combining suitable complexing agents with the' also more or less complexing depending on the constitution acting dicarboxylic acids according to the invention it is possible solutions - any stability (even cooking stability with pH = 6), but it is advisable not to add more to the auxiliary substance than is necessary to ensure sufficient To ensure processing security and to avoid impairment to avoid previous hardening. > - - -w

It is noteworthy that the addition of dicarboxylic acids according to the invention, alone or in combination with other complexing agents, stabilized ferricyanide baths have a lower tendency to deposit ^: Prussian blue than phosphate-buffered solutions. ■

The bleaching baths composed according to the invention can be used by Mt Väifeil in all photographic processes, in "d" eneia a silver picture created next to the dye picture or in the picture existing silver-containing auxiliary layers have to be removed Use common fixatives. ; '-; -, .- ■; .. -

lOl following examples for a more detailed description of the invention ,

Example 1 ^; -: ν - - - -> /. - - = ■; ■ ·: -: -.-. ■ -. '■■■■. ■■■, ..' ■ - ■ - ■■ - ': ■ .:

A conventional multi-layer parbilmmaterial 'mit-inkor-' intended for processing at 2O ^{0 G.} porated äXffusibnsfesteh color couplers was exposed imagewise uricTfolgender ^ processing at 30 ⁰ C subject to (Verarbeitungsgsing I):

A-G 652 - 5---

2.0 g / l 50.0 g / l 3.0 g / l 6.0 g / l 35.0 g / l 2.0 g / l 6.0 ml / 1 .1 »25 «A 10.2 30.0 g / l 20.0 g / l 25.0 g / l 3.75 First developer ;

. Black and white liegative development in a developer of the

following ^composition: iiJyfl

Tetrasodium salt d. Ethylenediamine .....

tetraacetic acid sodium sulfite, sicc. N-methyl-p-aminophenol sulfate Hydroquinone Sodium carbonate, sicc. Potassium bromide

Potassium iodide 0.1 i 'solution pH Kaiiumrhodanid

2. Stop "and hardening in the following bath:

Glacial acetic acid.:

Sodium borate, fentahydrate Potash alum, Krist.

pH (regenerator)

as a working solution mixed with approx. 20 J pH 4.6 +0.2

3. Watering and uniform reverse lighting

4. Color reversal development with the following color developer:

Trisodium salt d. Nitrilotriacetic acid 2.0 g / l sodium sulfite, sicc. 5 _t o g / l

N, N-diethyl-p-phenylenediamine sulfate 5.0 g / l Potassium carbonate, sicc. 50.0 g / l Potassium bromide. . , .1.0 g / l. Sodium sulfate, sicc. 40.0 g / l

Xthylenediamine 50% 16.0 ml / 1 Hydroxylamine sulfate 1.5 g / l

pH 11.7

5. Stop in the following interrupter pool:

Glacial acetic acid 40.0 ml / 1 Sodium acetate, sicc. 4.0 g / l

pH (regenerator) 3 _f 5

as a use, the LöBung offset about £ 20 of color developer;

pH 4.6 + ^, 2 ■ ■■ -. "■■ ■■ ■ '■ ... .-,. ■ -, -.

7. Bleaching in a bath of the following composition (bath A):

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Bad A

β / 1

Sodium borate,
Pentahydrate 16.0 Adipic acid 10.0 Sodium sulfate,
anhydrous 20.0 Potassium bromide 30.0

(Comparative example)

Bath B g / l

Disodium phosphate,

anhydrous 12.0

Glacial acetic acid 3.0

Sodium sulfate 20.0

Potassium ferricyanide 100.0 pH adjusted to 5.3 + o » ¹

8. Soak

9. Fixing in the following fixer bath:

Potassium bromide 30.0 Potassium ferricyanide 100.0 pH adjusted to 5.3+ Q, 1

AaaoniuathioBulfat Vatrluaeulfit, eicc.

pH

120.0 g / l
10.0 g / l

7.5

10. Soak

11. Final treatment with a bath containing HetsBlttel, prepared with softened water.

The film strips treated with bath A according to the invention showed perfect layer adhesion and surface properties. If, on the other hand, with otherwise unchanged processing, bath A was replaced by bath B of the usual composition,
that is about the same in the specified pH range
Has buffer capacity, the film strips showed signs of delamination and severe wrinkles.

A-G 652

BAD ORlGiNAt

Example 2

The processing described in Example 1 was repeated with the difference that the adipic acid in the bleaching recipe A is replaced by equimolar amounts of succinic acid or glutaric acid became.

As with adipic acid, good results were obtained, which differ advantageously from those obtained with bleaching bath B (which corresponds to the state of Technology).

Example 5

The processing described in Example 1 was repeated with the difference that the adipic acid in the bleach bath recipe is replaced by the equimolar amount of diethylmalonic acid and the pH was adjusted to 7.0. Likewise, the pH of solution B was raised to 7.0. As in the previous examples were layer adhesion and surface properties of the Samples bleached in bath A composed according to the invention are clearly superior to the comparison samples.

Example 4

A conventional 'Mehrschiehten-Fnrbnegativmaterial with incorporated, non-diffusing color couplers and mask couplers was exposed imagewise, and the following short processing at 30 ⁰ O subjected (processing transition II):

1. Development in the color negative developer of the following composition:

Sodium hexametaphosphate 2.6 g / l

KatriumBülfit, sicc. 2.0 g / l

Ν, Η-diethyl-p-phenyieüdiaiaiasulfat 2.0 g / l

Sodium carbonate, sicc, 40.0 g / l

Hatric sulfate, eicc. 60.0 g / l

Potassium bromide 1.5 g / l

Hydroxylamine sulfate 1.5 g / l

pH 10.6

" ^{G 652} - ⁸ -

109849/1477

2. Post-development in the intermediate bath;

Sodium laborate, pentahydrate 10.0 g / 1 Sodium sulfate 30.0 g / 1

pH (regenerator) 9 »2

as a working solution mixed with approx. 10 # developer, pH = 9.3

3. Stopping and hardening in a bath of the following composition:

Bath recipe C (regenerator solution)

Sodium acetate, anhydrous 17.0 g / 1

Potash alum, Krist. .30.0. g / 1

Boric acid 10.0 g / 1

White couplers of the following formula

(according to German patent specification

1 155 675): 4.0 g / 1

H, C -C- G - CH (C ₉ H ₁ -) -

N C = 0

pH 4.4 + 0.2
4. Bleaching in a bath of the following composition:

Comparative example% Bath recipe I) (regenerator solution) Bath recipe E (working solution)

g / 1 g / 1

Sodium hydroxide approx. 33.0

Adipic acid 60.0 sodium hema-metaphosphate 2.0

Trisodium citrate 3.5 disodium phosphate 6.0

Boric acid 5.0 monopotassium phosphate 16.0

Ealium bromide 20.0 Potassium bromide 12.0

60.0 potassium ferricyanide 42.0

pH 6.2 + 0.1 pH 6.0:

(pH of the ready-to-use solution: 6.0)

5. Fixing in the following bath:

Ammonium thiosulfate 120.0 g / 1

iifit 10.0 g / 1

BADORlGfMAI.

6. barrels (two-stage)

7. Foam treatment with a bath containing a wetting agent, made up with softened water.

The films developed in this way with recipe D were free of wrinkles and of excellent surface gloss, in addition free of color haze (bleach haze) or clouding of the layers due to embedded solids.

Should also be noted that to tighten the examination bath wetting agent (7) in the use solution containing all the baths, with the exception of the developer (1) and the 20 ^c /> addition of the respective preceding bath and maintained by regeneration in this state vmrden ; the regeneration rates required for this were partly below the values customary in conventional processes. In separate tests it was found that; the processing security extends over a range of about 5 to nearly 30% impurity and all bathrooms are still completely stable to flocculation even at impurity up to the tolerance limit to 80 ⁰ C. This is advantageous in particular when bleaching bath with pH = 6 and the given at 30 </ <> impurity KaIi- alum w of about 8 g / l and most surprising.

Instead of the bleach bath according to the invention, a similar one is used Compound bath with phosphate buffer ends / ends (recipe E), if the described processing procedure is maintained excessive deposits of aluminum phosphate both on the films and in the solution; an operation without intermediate watering is not possible. If you do without the phosphate and try Preparing the bath with pure acetate buffer is the buffer capacity at pH 6.0, a. pH ,,, which is responsible for the formation of the

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BATH ORIGINAL

developed films is essential, completely inadequate, in particular if larger amounts of the strongly buffered acidic hardness stop bath are brought in. Citric acid is available as a buffer also not usable, as they are in the to achieve the necessary buffer capacity required concentrations as a result of complex formation to soften the films and complete Floating the layers leads.

Example 5

A conventional * normally provided for processing at 2O ⁰ G, multilayered masked color negative photographic material was subjected to two different processing Come, wherein the processing temperature was increased in stages from an initial 40 ⁰ C to 45 and 50 ⁰ C. To compensate for the faster processes at elevated temperatures, the residence times in the baths were gradually shortened, but no ^T * ert was placed on an exact adjustment of the sensitometric values.

Processing stage III

Processing IV

1. Color negative developer

2. Post-development bath

3. Hardness stop clarifying bath

——. 3a

4. Bleach bath according to the invention

6. Soaking

7. Liquor bath

(together)

Hardness fixing bath

"Watering ■

ph ο s pha tge buff e r t e s Bleach bath

Watering

(together)

A-G 652

- 11 -

BATH ORIGINAL

Processing stage III corresponds to "in the bath sequence and composition the process described in example 3 with the exception, that instead of the normal fixer, a hardening fixer based on chrome alum of the following composition is used became: · "

Chrome alum 15.0 g / l Sodium bisulfite 3.5 g / l Sodium sulfite 6.0 g / l Sodium acetate, sicc. 10.0 g / l Ammonium thio-oil 120.0 g / l

pH 5.5 ■: -.--.

Processing step IV again differs in that "instead of the bleaching bath according to the invention (recipe D) a conventional one phosphate-buffered bleach bath (recipe E) was used, whereby a precipitation reaction of the phosphate with the in Avoid hardening agents used in baths 3 and 5, ■ intermediate washings had to be inserted.

While III after processing passage developed film strips having a flawless' Obetfflächenbeschaffenheit even at 50 ⁰ C, was seen in the developed after processing IV samples already at 45 ⁰ C light Runzelkorn that at 50 ⁰ C in a complete cross-linking d-er "emulsion layer The drying time of the samples processed according to IV was also about 20 ^a / c longer than the time achieved with processing step III according to the invention.

The advantage of the composite according to the invention. So bleaching bath consists in a short processing without intermediate washings .aaögl I will. Inserting intermediate waterings not only has the disadvantage of a longer processing time, sanding, but also of a greater dependence of the layer swelling on the: water temperature and water quality. In the case of other things, especially when processing at elevated temperatures, e.g. between 30 and 50 . ⁰ G, more energy is required for water treatment and water temperature control. This is also omitted in the bleach bath according to the invention.

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BATH

Claims (1)

M'tent claims Method of making color photqg ^ aphisoheE images through negative or ii & honest processing, whereby a be * cleared, at least one SilberhalQgenidemulsJ.c-ns ^ layer containing ptiotographiseheslfeteria.! f developed and the resulting silver image ^ and is fixed »characterized by, that the Increase in the presence of di-carboxylic acids of the following. formula ..-_ ■ - ■ ι '.? «? ■■ · ■■ · ■ - ■ · - ■ where mean ''. η, m, ρ? = whole numbers between 1 «5 with the condition that η + m + ρ ^? ,. R _i? Ro, R ₇ T, R * = hydrogen, alkyl with up to 5 Q «atoms. is carried out-,- 2. Process according to claim 1, characterized in that R ^ j, R ₂ , R ₅ or R ^ denotes methyl or ityl ^ ■ 3.? Experience according to claim 1, characterized in that the bleach baths additionally for multi-valued metallization Completely form? id ^ acting mouths in such quantities contain that the action of polyvalent metal ions not as a hardening agent for the layer bathing agent is negatively influenced » ^A - ^S652 ■ - ■ "> ■ 109849/1477 4, Photographic bleach-fix gum bleaching of silver images when processing color photo graphic materials, which contain an oxidizing agent. that dicarboxylic acids of the following formula EOQQ- (CH ₂ ) ^ _T - C - (CH ₂ Jg ^ - Q ~~ (QiIr, ) - ^ - COOH in which, mean n, m, p = whole number between 1 - 5 with 4-way condition,
that η + m + ρ ^ 7 R ₁ , Ro, R ^, E ^ = hydrogen, alkyl with up to 5 0 atoms are included, " 5. Aqueous bleaching bath according to claim 4, characterized in that R ₁ , Rpj Rz or R. is methyl or ethyl. 6. Aqueous bleaching bath according to claim 1, characterized in that the bleaching baths additionally contain fWe polyvalent metal ions complex-forming compounds in such amounts that the effect of the polyvalent metal ions as hardening agents for the layer binder is not adversely affected. A-G 652 -U- • 1689 * 3/1477