DE2110521C3 - Multilayer color photographic material - Google Patents

Description

55

> The invention relates to a color photographic layer recording material which is hydrophilic Contains loid layers of different sensitized silver> genide emulsions in which the color decays by reacting an oxidized primary ■ natural amine as a color developing agent with Couplers can be used to generate color images, with one of the hydrophilic colloid layers inside jersion of a non-diffusing anti-irritant based on a sec-alkyl hydrochloride derivative contains.

It is well known that in the color development of color photographic recording materials in the Emulsion layers can easily appear color bleeding, the formation of which is due to the fact that the Color developing agents are oxidized when exposed to atmospheric oxygen and the oxidized color developing agents Coupling with color couplers in those areas in which no silver image has been produced. The appearance of color haze is; to be found especially in the case of recording materials in the light-sensitive layers Color coupler included.

In order to prevent the occurrence of color fog in color photographic recording materials, it is known to incorporate hydroquinone derivatives into the recording materials as anti-discoloration agents. From US-PS 24 03 721, for example, the use of 2,6-di-n-dodecylhydroquinone, from US-PS 27 28 659 the use of 2-n-alkylhydroquinones, for. B. 2-n-dodecylhydroquinone, from US Pat. No. 2,732,300 the use of asymmetrical dialkylhydricquinones, e.g. B. 2-sec.-OctadecyI-5-methylhydroquinone and from US Pat. No. 2,701,197 the use of sulfonated hydroquinones, e.g. B. sulfonated sec-undecylhydroquinone known.

However, it has been shown that the alkyl and dialkyihydroquinones used hitherto have certain Adhering disadvantages. Many of them are difficult to manufacture in two to four-step processes, others have molecular weights that are too low to be used in multilayer color photographic recording materials migrate between the individual layers, resulting in undesirable side effects, while others crystallize during or after the coating process and deliver poor quality layers while in turn other alkylhydroquinones are subject to oxidation during the coating or during the Develop colored by-products.

The object of the invention is to provide a multilayer color photographic recording material with a Indicate anti-discoloration agents in which the air oxidation of color developing agents is certain is prevented and no crystallization of the anti-discoloration agent he follows.

The invention was based on the knowledge that this object can be achieved that one as Anti-discoloration agent uses a mixture of isomers of at least two secondary dedocylhydroquinones.

The invention accordingly provides a multilayer color photographic recording material, which contains hydrophilic colloid layers from differently sensitized silver halide emulsions, in which in color development by reacting an oxidized primary aromatic amine as Color developer compound with color couplers color images are generated, at least one of the hydrophilic colloid layers a dispersion of a non-diffusing anti-staining agent on the Contains base of a sec-alkylhydroquinone derivative that is characterized in that it consists of a mixture of isomers as a non-diffusing anti-discoloration agent at least two Scc.-Dodecymydrochinüiicri eiuhäii.

In the simplest mixtures, which contain two different sec-dodecylhydroquinones, there is one Compound usually in a concentration of 1 to 99 wt .-% and the other compound in einpr

■)

concentration of 99 to 1% by weight. One compound is preferably present in a concentration of 5 to 95% by weight and the other compound in a concentration of 95 to 5% by weight. According to the invention, the most varied of mixtures of ic-dodecyl hydroquinones can be used. For example, the following can be used:

1. Mixtures of 2-sec-Dodecylhydroquinonen, in which the compounds differ in the number and / or arrangement (positional isomers) of the carbon atoms differentiate in the alkyl groups,

2. Mixtures of 2,5-di-sec-dodecylhydroquinones, in which the compounds are in the number and / or the arrangement of the carbon atoms in the alkyl group on one of the two substituents, ie in the 2- and 5-position differ, as well

3. Mixtures of the mixtures described under 1. and 2..

Mixtures used with preference are mixtures of isomers of a 2-sec-dodecylhydroquinone, mixtures of isomers of a 2,5-di-sec-dodecylhydroquinone or mixtures of a 2-sec-dodecylhydroquinone (a single compound or mixtures of two or more isomers) and one 2,5-di-sec-dodecylhydroquinone (a single compound or mixtures of 2 or more isomers).

The isomer mixtures used according to the invention are expediently prepared by reacting hydroquinone with the corresponding primary olefin in the presence of a Lewis acid at elevated temperatures over a prolonged period, so that isomeric forms of the primary olefin are formed which with the hydroquinone to form at least one minosubstitute sec-dodecylhydroquinone and at least one disubstituted sec-dodecylhydroquinone react in one reaction stage. An inert solvent, preferably a water-immiscible solvent, for example benzene or nitrobenzene, is expediently used for the reaction mixture. Toluene or xylene is used. Lewis acids are protons and proton donors, for example acids, as well as metal atoms that are able to form coordination systems with water or ammonia, the sulfur of sulfur dioxide, sulfuric acid, sodium bisulfite and atoms and free radicals with incomplete electron shells. Particularly suitable Lewis acids are sulfuric acid, phosphoric acid, hydrochloric acid, sodium bisulfate, monosodium phosphate, zinc chloride, aluminum chloride, boron trifluoride, benzenesulfonic acid, silicon dioxide-aluminum oxide mixtures and acidic ion exchange resins. It has proven advantageous to heat a solution of the hydroquinone in a solvent together with the Lewis acid in order to remove any moisture from the mixture in the form of an azeotropic mixture and then the primary olefin while increasing the temperature of the reaction mixture to a temperature of to add about 130 to about 240 ⁰ C over a longer period of time. The rate at which the olefin is added to the reaction mixture, the rate of heating and the reaction time can be controlled so that the desired isomeric is present in the final product. The most favorable reaction conditions depend on the particular mixture of isomers desired and can easily be determined. After the reaction has ended, the reaction mixture is cooled and poured into a suitable organic solvent, for example ligroin. The Lewis acid is removed by filtration or any other suitable measure. The unreacted olefin is separated off by distillation under reduced pressure. The isomer mixture is then distilled under reduced pressure or separated from the remaining reaction mixture by any other suitable measure

ίο be protected by having it under a Maintained nitrogen atmosphere

Examples of particularly advantageous isomer mixtures which can be used according to the invention are:

Mix 1

2- (l-methylundecyl) hydroquinone,

2- (l -ethyldecyl) hydroquinone,

2 (1- butyloctyl) hydroquinone,

2- (1 - amyiheptyl) hydroquinone,
2,5-di (1-methylundecyl hydroquinone,

2,5-di (l-ethyldecyl) hydroquinone,

2,5-üi (1-butyloctyl hydroquinone,

2,5-di (1-propylnonyl) hydroquinone,

2,5-di (l-amylheptyl) hydroquinone,
2- (l-methylundecyl) -5- (l-propylnonyl) hydroquinone,

2- (1 · methylundecyl) -5- (1-ethyldecyljhydroquinone,

2- (l-methylundecyl) -5- (l-butyloctyl) hydroquinone,

2- (l-methylundecyl) -5- (l-amy! Heptyl) hydroquinone,

2- (l-ethyldecyl) -5- (l-butyloctyl) hydroquinone,
2- (l-butyloctyl) -5- (l-amylheptyl) hydroquinone and

2- (1-propylnonyl) -5- (1-amylheptyl) hydroquinone.

Mixture 2

Like mixture 2, but with the following additional compounds:

2- (l-propylnonyl) hydroquinone,

2- (1-EthyIdecyl) -5- (l -propylnonyl) hydroquinone,

2- (1-ethyldecyl) -5-5 (1-amylheptyl) hydroquinone and

2- (1-propyl nonyl) -5- (1-butyloctyl) hydroquinone.

Mixture 3

Like mixture 2, however, it contains 2- (l-propylnonyl) hydroquinone instead of 2- (l-amylheptyl) hydroquinone and 2 (1-ethyldecyl) -5- (? -propylnonylhydroquinone, 2- (1-Ethyldecyl) -5- (1-amylheptyl) -hydroquinone and 2- (1-propylnonyl) -5- (1-butyloctyl) hydroquinone in place of of 2- (1-propylnonyl) -5- (1-amylheptyl) hydroquinone and 2- (l-butyloctyl) -5- (l-amylheptyl) hydroquinone.

Mix 4

2- (1-methylundecyl) hydroquinone and
2,5-Di- (I -melhylundecyl) hydroquinone.

Mix 5

2- (l-methylundecyl) hydroquinone,
2,5-di (l-methylundecyl) hydroquinone,
2,5-Di (I -ethyldecyl) hydroquinone and
2- (l-methylundecyl) -5- (l-ethyldecyl) hydroquinone.
The mixtures used according to the invention are eutectic mixtures or almost eutectic mixtures. The isomer mixtures can be used in the known photographic hydrophilic colloids, e.g. B. gelatin, albumin, collodion, gum arabic, agar-agar, cellulose derivatives, such as alkyl

frs esters of carboxylated cellulose, hydroxyethyl cellulose, Polymers, e.g. the amphoteric copolymers known from US Pat. No. 29 49 442, polyvinyl alcohol, Polyvinylpyrrolidone and copolymers

from an alkyl acrylate, an alkylcarbonylacetoxyalkyl acrylate and a sulfoalkyl acrylate or acrylic acid, as described, for example, in US Pat. No. 3,488,708 are known to be dispersed. The isomer mixtures which are liquid at room temperature can be used without Disperse using a solvent. The isomer mixtures that are not liquid at room temperature are expediently in the form of a solution in

1. a high-boiling organic "crystalloidal" Solvent, d. H. an organic solvent which is practically insoluble in water and has a low Molecular weight with a boiling point greater than about 175 ° C, for example alkyl esters of phthalic acid, e.g. B. methyl phthalate, ethyl phthalate, propyl phthalate, n-butyl phthalate, di-n-8utyl phthalate, n-amyl phthalate, isoamyl phthalate and dioctyl phthalate, esters of phosphoric acid, e.g. B. Triphenyl phosphate, tricresyl phosphate, diphenyl mono-p-tert-butyl phenyl phosphate or

2. low-boiling organic solvents, such as z. B. short-chain alkyl acetates, ethyl propionate, sec-bulyl alcohol, methyl isobutyl ketone, /? - Äthoxyäthylacctat, Methyl cellosol acetate and acetylacetone

dispersed.

The dispersions which can be prepared from the isomer mixtures in hydrophilic colloids are notable characterized in that they are stored at temperatures below room temperature before, during and after the coating of the substrate does not crystallize. The one using the isomer mixtures The dispersions produced are also distinguished by the fact that they do not lead to discoloration. the Dispersions can be incorporated into any layer of a multilayered pholographic recording material, in which anti-stain agents are used. For example, you can Incorporated into one or more light-sensitive layers of a multilayer recording material will. They can be used in photographic recording materials in the light-sensitive emulsion layers Contain color couplers, or in recording materials that do not contain color couplers, be used. The multilayer recording materials can either be camera-sensitive: Recording materials are or such as are used for the production of color prints be used. The recording materials can be conventional substrates made of, for example, paper, Cellulose acetate or synthetic polymers such as are commonly used.

The isomer mixtures are in the hydrophilic colloids in concentrations of 0.01 to 90, preferably from I to 85% by weight, based on the dry hydrophilic colloid, dispersed. The optimal one Concentration depends on the particular photographic recording material in which the anti-discoloration agent is used should be used. It can easily be determined by known methods.

The isomer mixtures used in accordance with the invention cause a reduction in the oxidized form of any one of the primary aromatic Amine existing color developing agent to the developing agent or to a form which is associated with a color coupler does not couple. To prevent the migration of a by developing in a photosensitive Layer formed oxidized color developer compound into another layer with discoloration of the other layer have hydrophilicity arranged between two light-sensitive layers Colloid layers containing a mixture of isomers proved to be very effective. The following examples are intended to explain the invention in greater detail.

example 1

A. The 2,5-di-n-dodecylhydroquinone known from US Pat. No. 2,728,659 as an anti-discoloration agent, subsequently Denoted as anti-discoloration agent X, was in a four-step process according to US Pat. No. 2,728,659 Column 8, lines 48-68. 108-110 ° C.

B. A mixture of isomers of sec-dodecylhydrochino nen was made as follows:

In a 500 m capacity four-necked flask in an oil bath equipped with a stirrer, a distillation head, a dropping funnel and a thermometer, 55 g of hydroquinone, 18 g of a silica-alumina catalyst and 100 ml of toluene were introduced. The reaction mixture was heated with stirring, an azeotropic toluene / water mixture being distilled off. After distilling off about 75 ml of mixture, the temperature of the flask was about 13O ⁰ C. To the hot reaction mixture then 150 ml of 1-dodecene was added. Thereafter, the temperature of the oil bath was heated to 230 ⁰ C. The reaction temperature rose to 220 ° C over a period of two hours. After a temperature of 220 to 225 ° C. had been maintained for one hour, a further 100 ml of 1-dodecene were added dropwise at such a rate that the temperature of the reaction mixture did not drop. After stirring for another three hours at this

Temperature, the flask was removed from the oil bath. The reaction product was kept under a nitrogen atmosphere to avoid oxidation. After the reaction mixture had cooled to 120 ° C., it was carefully poured into 500 ml of ligroin. The silica-alumina catalyst was filtered off and washed with ligroin. The ligroin was then distilled off from the reaction product at atmospheric pressure. The unreacted dodecene was removed by distillation under reduced pressure to give a fraction boiling at 78-110 ⁰ GMO mm Hg fraction was collected. The reaction product was distilled in the vacuum created by means of an oil pump, a fraction boiling at 210-250 ° C./0.15 mm Hg being collected. The yield of reaction product was 185 g, corresponding to 83% of the theoretical amount of 226 g, based on the amount of hydroquinone used. The obtained isomer mixture, hereinafter referred to as anti-discoloration agent A, was liquid at room temperature. A gas chromatogram showed that the mixture consisted of 12 out of fifteen possible disubstituted isomers (95% by weight) and four out of five possible monosubstituted isomers (5% by weight).

C. Dispersions of the following composition were prepared from the anti-discolouring agents A and X: 50 g anti-discolouring agent,
25 g tricresyl phosphate,
60 g gelatin dissolved in 600 ml water.

Immediately after their preparation, the dispersions were applied to customary layer supports in such a way that 6470 mg of gelatin were used ^{on a layer support area of 1 m 2.}

10

15th

The following resulted:

Compound X immediately crystallized, which is evident from a photomicrograph of the cross section of generated layer was recognizable. In the case of the layer formed from the anti-discoloration agent A, no crystallization found.

In another experiment, the anti-staining agent A and X containing dispersions were held for two hours at a temperature of 40 ⁰ C and then examined for crystal formation. Crystal formation occurred only in the dispersion containing the anti-discoloration agent X. During storage, the dispersion containing the anti-discoloration agent X turned blue due to the oxidation of the hydroquinone to a colored quinhydrone. The results obtained show that an isomer mixture which can be used in accordance with the invention is superior to the anti-discoloration agent X in terms of its resistance to oxidation.

Example 2

It became another well-known anti-stain agent. namely 2,5-di-tert-octylhydroquinone (cf. US-PS 20 08 032 and 20 08 337) - hereinafter referred to as anti-discoloration agent Y - with the in Example IB described anti-stain agent A compared. For this purpose, two dispersions were made manufactured as follows:

1. It became a solution of 40 g of the anti-stain agent Y made in 20 g tricresyl phosphate. The solution was dispersed in one liter of 8% aqueous gelatin.

2. A solution of 40 g of anti-discoloration agent A in 20 g of tricresyl phosphate was made. the Solution was also dispersed in one liter of 8% aqueous gelatin.

The two dispersions were kept for two weeks at a temperature of -3.9 ° C (25 ° F) and 45% relative humidity. Crystallized from the dispersion containing the anti-discoloration agent Y the anti-stain agent off. To the inferior quality of the anti-discoloration agent Y containing To show dispersion, the dispersion was melted and filtered. A considerable one remained Part of the crystallized anti-discoloration agent Y back on the filter. In the anti-discoloration dispersion A, on the other hand, no crystal formation occurred. The dispersion passed the filter with no residue.

Example 3

Three multilayer color photographic recording materials with paper backings of the structure specified below were exposed through a test object with density levels, developed in color, bleached, fixed, washed and dried.

Recording material No. 1

Layer 3 (top layer)

1080 mg of gelatin / m ^2, 540 mg cyan color-forming coupler / m ^2, 540 mg of dibutyl phthalate / m ^2;

Layer 2 (middle layer)
1080 mg gelatin / m ² ;

Layer 1 (lowest layer)

3230 mg gelatin / m ² , 2160 mg silver halide / m ² . 1080 mg yellow color coupler / m ² .1080 mg dibutyphthalate / m ² .

Recording material No. 2

As material no. 1, but with 280 mg anti-discoloration agent X / m ² in layer 2, dispersed as described in example 2.

Recording material no. 3

As material no. 1, but with 280 mg anti-discoloration agent A / m ² in layer 2, dispersed as described in example 2.

The effectiveness of the anti-discoloration agents A and X was determined by determining the amount of in layer 3 blue-green dye formed, which is determined by the reaction of oxidized color developing agent of Layer 1 with the Layer 3 coupler. The results obtained are in the listed in the following table:

Material no.

Anti-discoloration agent

Density of the cyan dye

25 1 without 0.95 2 X 0.64 3 A. 0.42

The results show that the anti-discoloration agent A usable in the present invention is similar to the known one Anti-stain agent X was clearly superior in terms of its effectiveness.

The cyan color coupler used in layer 3 was one Coupler of the type known from US Pat. No. 2,801,171. In the case of the yellow color coupler used in layer 1 it is a -pivalylacetanilide coupler of the type known from US Pat. No. 3,265,506. In the The silver halide emulsion used was a silver bromide iodide emulsion. The used Color developing, bleaching and fixing solutions had the following compositions:

Color developing solution

Benzyl alcohol 12.6 ml

Sodium hexametaphosphate 2.0 g

anhydrous sodium sulfite 2.1 g

Sodium carbonate monohydrate 26.8 g

Sodium bicarbonate 2.9 g

Potassium bromide 0.48 g

Sodium chloride 0.7 g

Hydroxylamine sulfate 2, 'g

Color developer +) 4.2 g

pH at 23.9 ⁰ C 9.96 Water to make to 1 liter

⁺ ) 4-Aniino-N-ethyl-N- (/ J-mcthansuHonamidoethyl) -m-tolidin-sesquisulfate monohydrate

Blood solution Sodium nitrate 45.0 g Potassium ferricyanide 22.5 g Potassium bromide 8.2 g Boric acid 7.5 g borax 0.97 Made up to 1 liter with water

709 636

Fixing solution Sodium thiosulfate 223.0 g Sodium bisulfite 12.0 g anhydrous sodium acetate 14.0 g Sodium citrate 1.7 g Boric acid 5.0 g Potassium aluminum sulphate (granules) 24.0 g Made up to 1 liter with water Example 4

A mixture of 50 g of anti-discoloration agent A and 60 g of gelatin in 600 ml of water was passed through three times given a colloid mill. The dispersion obtained was in comparison with the dispersions of Example 1 about 19% lighter. The liquid anti-discoloration agent required to prepare a ha '.- barable dispersion no other solvent. In the photographic tests it was found that this dispersion with a corresponding dispersion in a solvent was practically identical.

Example 5

Further dispersions were prepared according to the method described in Example IC, this time but instead of gelatin equivalent amounts of collodion, agar-agar, hydroxyethyl cellulose, polyvinyl alcohol, Polyvinylpyrrolidone or a copolymer of methyl acrylate, 3-acryloyloxy-1-methylpropane-1-sulfonate, Sodium salt and 2-acetoacetoxyethyl acrylate were used. There were corresponding Results obtained as described in Example IC.

Example 6

There were two multilayer color photographic recording materials A and X of FIG US-PS 22 52 718 known type made. They consisted of a layer support, a red-sensitized one Gelatin silver bromide iodide emulsion layer, a gelatin layer, a green sensitized gelatin silver bromide iodide emulsion layer, a gelatin layer containing a bleachable yellow dye; and a blue sensitive gelaline silver bromide iodide emulsion layer in the order given. In the gelatin layers between the photosensitive ones However, anti-discoloration agents were dispersed in layers. Those containing an anti-discoloration agent Layers of the recording material X were made using the dispersions described in Example IC manufactured. It was found that the anti-discoloration agent X was in the dispersion before, during and crystallized out after the coating process, which led to coating defects, so that the Anti-discoloration agent X was not usable.

The recording material A crystallized from the layers containing the anti-discoloration agent A In contrast, the anti-discoloration agent A neither during nor after the coating process. The recording material A was free from coating defects.

Sections of the recording materials A and X were exposed imagewise and then afterwards the US-PS 22 52 718 known method developed. While in the developed recording material X a blue-green discoloration of the magenta image layer occurred, the recording material A was free from any discoloration.

ίο Example 7

Two multilayer color recording

materials 1 and 2 according to Example 2, column 7, line 56 to column 8, line 28 of US-PS 29 56 879 prepared in to which the following layers have been applied to a substrate:

1. a blue-sensitive gelatin silver chlorobromide emulsion layer containing a yellow color coupler and an anti-discoloration agent;
2. a gelatin layer,

3. a green sensitized one containing an anti-discoloration agent Gelatin silver chlorobromide emulsion layer,

4. An ultraviolet light absorbing compound and an anti-discoloring agent containing Gelatin layer and

5. A red sensitized gelatin syllable bromide iodide emulsion layer containing an anti-stain agent.

The recording materials were those described in Example 2 of said US Pat Recording materials identical with the exception that in the recording material 1 a dispersion of the anti-discoloration agent X as in Examples IA and IC is used as an anti-discoloring agent in each of the anti-discoloring agent-containing layers would. The crystallization of the anti-discoloration agent X from the dispersion before, during and after Coating process resulted in serious coating failures.

The recording material 2 corresponded to the recording material 1 with the exception that as Anti-stain agent instead of dispersing anti-stain agent X in each of an anti-stain agent containing layers a dispersion of the anti-discoloration agent A, as in Examples 1B and IC described was used. In this case, there were no crystallization problems whatsoever.

Sections of the recording materials 1 and 2 were exposed imagewise and developed according to the development process known from US Pat. No. 2,956,879. It was found that the recording material 2 according to the invention was qualitatively superior to the recording material 1.

B e i s ρ i e 1 8

Five different recording maicria AE of the following structure were produced (the concentrations given in the following relate to mg / dm ^{2 of the} substrate area):

Recording material A

The following layers were applied to a paper backing in the following order:

Layer 1:

Gelatin layer with 10.7 mg gelatin;

Layer 2:

Gelatin-silver halide emulsion layers containing 32.1 mg gelatin, 21.4 mg silver halide, 10.7 mg a yellow dye-forming coupler +) dissolved in 10.7 mg of di-n-butyl phthalate as a coupler solvent;

Layer 3:

Gelatin layer with 10.7 mg gelatin;

Layer 4:

Gelatin layer without silver halide with 10.7 mg gelatin and 5.35 mg of a coupler providing a blue-green dye + ⁺ ), dissolved in 5.35 mg of di-n-butyl phthalate as a coupler solvent.

Recording material E (according to the invention):

This recording material differed from recording material D only in that layer 3 additionally contained 2.86 mg of the isomer mixture.

The amounts of sea-dodecy! Hydroquinone used were equivalent to the amounts of 2,5-di-sec-octylhydroquinone used.

Sections of the recording materials were exposed in a sensitometer to white light through a test object with graduated density levels (21 levels with a density range from 0.0 to 3.0). The exposed sections were then developed ^{at 20 ° C. as follows:}

Recording material B

This recording material differed from recording material A only in that layer 3 additionally contains 1.07 mg 2,5-di-sec-octylhydroquinone of the following formula:

OH

CH ₁₇ -see.

OH

Recording material C

This recording material differed from recording material A only in that layer 3 additionally contained 2.14 mg of 2,5-di-sec-octylhydroquinone.

Recording material D (according to the invention):

This recording material differed from recording material A only in that layer 3 an additional 1.43 mg of an isomer mixture of sec-dodecylhydroquinones, prepared as in Example IB described, contained.

+) The color coupler consisted of:
a-Pivalyl-2-chloro-5 -) '- (2,4-di-tert-aniylphnoxy) butyraniidoacetanilide of the formula:

(CH ₃ ) JCCOCH ₂ CONh- / O

NHCO (CH,), O- <O VC ₅ H ₁₁ -I

C ₅ H ₁₁ -I

+ ⁺ ) The color coupler consisted of:

2 - [«- (2,4-Di-tert.-amylphenoxy) butyramido] -4, f> -dichloro-5-methylphenol of the formula:
OH _r ,,

H ₁ C

Color development +) 10 min Interrupter fixer + +) 5 min To wash 5 min Bleach + + +) 5 min To wash 5 min Freeze + + + +) 5 min To wash 10 min dry

Cl

C ₅ H ₁₁ -I +) A color developer solution as described in lines 15-25 of column 8 of US Pat. No. 3,700,453 was used

++) It became a breaker fixer like in lines 38-44 of column 8 of US Pat. No. 3,700,453, is used.

+ + +) A bleach bath as described in lines 30-35 of column 8 of US Pat. No. 3,700,453 was used.

+ + + ⁺ ) The breaker fixer bath described was used.

If no oxidized color developing agent (generated as a result of the Development of the exposed silver halide of layer 3) migrates through layer 3 into layer 4, so no blue-green dye is produced in layer 4. In this case the test strip must be yellow Appearance of only a yellow dye in layer 2 due to coupling between oxidized color developing agent and the layer 2 yellow dye forming color coupler is formed.

In practice, however, some oxidized color developer molecules which have not reacted with the color coupler in layer 2 migrate into layer 4, in which they couple with the color coupler present here to produce a blue-green dye. The result is a green looking one! Test strips in which the yellow dye of layer 't absorbs blue light and the added blue-green dye of layer 4 absorbs red light (far minus blue minus red results in green).

The five test strips show the following:

The stripe of the recording material A is green due to the absence of an anti-fouling training agent or scavenger for the oxidized color developing agent in layer 3; Stripes B and C are also green, as the familiar Anti-discoloration agent 2,5-di-6-octylhydroquinone ii layer 3 ineffective in terms of preventing de Migration of oxidized paint developer compound is.

By contrast, the strips of recording materials D and 1 are yellow, since the isomers used Mixture of secondary dodecylhydroquinones effectively binds the migrating oxidized dyes winder connection guaranteed.

The 2,5-di-secoctylhydroquinone used to carry out the experiments (preparation of recording materials B and C) was produced using the following method:

toluene

OH

CH ₃

Spalturigs- WC - ^ λ
kalalysalor

OH
QH ₁ ,

A 1 liter three-necked round bottom flask equipped with a mechanical stirrer and distillation column was heated by means of an electrically heatable jacket. Then to the flask was added 220 grams (2 moles) of hydroquinone, 448 grams (4 moles) of 1-octene, approximately 5 grams of cleavage catalyst, and 150 ml of toluene. The water was distilled off in the form of an azeotropic mixture, whereupon the residue was heated ^{to 107 ° C. under pressure for 6 hours.} The reaction mixture was then extracted with ethyl acetate and filtered, whereupon the filtrate was concentrated under reduced pressure and then distilled.

Claims (4)

Patent claims: 1. multilayer color photographic recording material, the hydrophilic colloid layers of variously sensitized silver halide emulsions contains, in which the color development by reacting an oxidized primary aromatic amine as a color developer compound with color couplers color images are generated, where ι ο at least one of the hydrophilic colloid layers is a dispersion of a non-diffusing anti-staining agent based on a sec-alkylhydroquinone derivative contains, characterized in that it is used as a non-diffusing anti-discoloration agent contains an isomer mixture of at least two sec-dodecylhydroquinones 2. Multilayer color photographic recording material according to claim 1, characterized in that characterized in that it consists of a mixture of isomers as a non-diffusing anti-discoloration agent a) at least one mono-sec-dodecylhydroquinone with 1-methylundecyl, 1-ethyldecyl, 1-propylnonyl, 1-butyloctyl or l-amylheptyl radicals as sea-dodecyl substituents and b) at least one ^, S-sec.-dodecylhydroquinone with I-methylundecyl-, 1-ethyldecyl-, 1-propylnonyl-, Contains lbutyloctyl or 1-amylheptyl radicals as sea-dodecyl substituents. 3. Multilayer color photographic recording material according to claim I, characterized in that characterized in that it consists of a mixture of isomers as a non-diffusing anti-discoloration agent a) at least two mono-sec-dodecylhydroquinone isomers with 1-methylundecyl, 1-ethyldecyl, 1-propylnonyl, 1-butyloctyl or 1-amylheptyl radicals as sea-dodecyl substituents and b) at least two di-sec-dodecylhydroquinone isomers with 1-methylundecyl, 1-ethyldecyl, 1-propylnonyl, 1-butyloctyl or 1-amylheptyl radicals contains as sec-dodecyl substituents. 4. Multilayer color photographic recording material according to claim 1, characterized in that it consists of a mixture of isomers as the non-diffusing anti-discoloration agent a) four mono-sec-dodecylhydroquinone isomers with 1-methylundecyl-, 1-ethyldecyl-, 1-propylnonyl-, 1-butyloctyl or 1-amylheptyl radicals as substituents and b) twelve 2,5-di-sec-dodecylhydroquinone isomers with 1-methylundecyl, 1-ethyldecyl, I-propylnonyl, 1-butyloctyl or 1-amylheptyl radicals contains as substituents.