DE851723C - Process for the preparation of colored photographic images in a multicolor photographic emulsion - Google Patents

Description

The invention relates to, and particularly relates to, the treatment of color photographs Rinsing baths, through which the color decomposition of azo, Azine, azomethine, indophenol and quinone imine dyes is prevented.

Despite the usual precautions taken when storing color photographs and prints the color matching or the color balance is very often due to the effect of heat, particularly high humidity conditions and altered by residual chemicals resulting from the processing of the films or copies. This lack of color stability is very disadvantageous because it spoils valuable color photographs and become unusable. The change or deterioration makes up as yellowing or browning of the colored photograph noticeable when keeping or storing in one warm atmosphere takes place. Another disadvantage ao of the photographic colors often makes itself felt in one Fading of the yellow or other colors noticeable. This disadvantage occurs at high temperature and high humidity. This undesirable color deterioration occurs z. B. often »5 even when storing the colored photo

graphs in an attic room or even in a wallet. It was also found that colored prints, especially in the lights or white areas, have become brown or brown spots form due to the oxidation of the color developing agent contained in the Underlayer and is left behind in clumps of color or color aggregation. Deductions, which have been produced without color development,

ίο do not show this discoloration or staining. These undesirable effects are often seen in color photographs, the azomethine dyes contain. These changes naturally limit the storage options or Storage conditions so that procedures by which the resistance of these dyes against high humidity and fading due to chemical substances left behind are of great economic value.

The invention therefore aims to provide a new method for processing color photographs and the like, so that the original coloring is not detrimental even with high humidity influenced or destroyed.

Another object of the invention reads in the production of color photographs, their colors both 'heat resistant and resistant to the destructive effects of color development chemicals left behind.

It has been found that the above objectives can be achieved by using an aqueous final rinse Solution is used which is water-soluble in an amount preventing staining Contains addition product of formaldehyde and a urea. The urea compounds that easily react with formaldehyde, have the following general formula:

O = C

NR ₁

NH

in which R, R ₁ and R _{2 are} hydrogen or low molecular weight alkyls such as methyl, ethyl, propyl, allyl and butyl, and here R _{2 is} always hydrogen if both R and R _{1 are} alkyls.

The following examples represent suitable urea compounds that can be reacted with formaldehyde: urea, N-methyltinea, N-ethylurea, N-propylurea, N-butylurea, N, N-dimethylurea, N, N'-dimethylurea, N, N-diethylurea, N, N'-diethylurea.

The following compounds illustrate examples of reaction products from formaldehyde and ureas, which can be used as anti-staining agents:

O = C

NHCH ₂ OH

NH ₂

Bcr. 41, 26

N-methylolurea

NHCH ₂ OH = C NHCH ₂ OH Ber. 41, 20 O O , N'-dimethylolurea NHC ₂ H ₅ N N = Cf CH ₂ , HC ₂ H, 5 O η

NCH ₂ OH NH

Annalen 361, 134 N-Methylolmethylene-bis-monoethylurea

■ N (CH ₃ J ₂

Annals 361, 135

" ¹ NHCH ₂ OH

N'-methylol-N, N-dimethylurea

NCH,

Annals 361, 157

O = C:

CH ₂ OH

NHCH,

N-methylol-N, N'-dimethylurea

CH ₂ OH CA. 30, 5944 / CH _{2 -N}

C = O

CH ₂ -

CH ₂ OH

N, N'-dimethyloluron.

This knowledge made it possible to use farl> developed multicolor photographic material to make practically insensitive to the destructive effects of storage or aging, without detrimentally affecting the original color balance or color balance. Even the property of multicolored developed photographic materials, the azo, azine, azomethine, Indophenol and quinone imine dyes are essential to fade in high humidity Better if the colored photographs or transparencies produced are washed with water Solutions of the adducts mentioned from formaldehyde and ureas are treated. When these solutions are used as a final rinse, i. H. after complete processing of the multi-color photographic material, it prevents the color fading of the colored photographs, the high humidity conditions reduced or accelerated aging or to

setting of the original color balance acidic Have been exposed to vapors.

The concentration of the urea-formaldehyde addition products can be between about 0.5 and 20 per cent ran. Only minor improvements are obtained from higher concentrations. Through concentrations from about 2 to 5% good results are obtained. The flushing time is also variable and can be between 1 and 10 minutes.

However, the best results with a 3% solution are obtained when the film is finished Bathing for 3 to 5 minutes.

As a multicolor photographic material to be used with the stain prevention baths of the present invention Invention can be dealt with, color reversal films, color negative films, color reversible films Weil.Se, copier materials and color-positive copier papers applied to an opaque substrate can be used regardless of whether the dye images are present in the emulsion Color former or through a selective second exposure and subsequent development with developing solutions, containing color formers and color developers.

The color reversal film consists of a three-pack emulsion which forms a whole based on a conventional transparent base made of cellulose acetate or nitrate is coated. Any of these emulsions is sensitized to one of the main colors of light, namely blue, green and red. the top layer is sensitive to blue. Under this first layer there is a yellow filter layer which absorbs blue light. Under this filter layer there is a green-sensitive emulsion layer, and under this layer lies a red-sensitive emulsion layer. Each of these three halosilver emulsion layers contains color-forming components which are converted into an aromatic amine developer during the development of a silver image combine with the oxidation product of the developing agent to form a dye, or they can also be free of color formers, in which the film with the color formers is in the FarlRiitwicklern after the selective second exposure and color development processes are dealt with as in the American patents ι 897 866, 1900877. 1928709 and 1980941 is beschrklxMi.

Since silver is formed during development, it must be removed after color development by placing the film in a bleach bath in the usual way and then bathing it off Sodium thiosulfate is treated. In the blue-sensitive emulsion a yellow dye, a blue-red dye was formed in the green-sensitive emulsion and a blue-green dye was formed in the red-sensitive emulsion. By combination these three basic colors then become all other color tones in the finished film or print generated.

The color negative film is made in the same way as the color reversal film, with the difference that that he has a layer between the red-sensitive and the green-sensitive layer may contain pure clear gelatin. The color reversible white opaque material becomes in the same way as the color reversible and color negative film and the color negative film produced, but an opaque white film is used as the support. The coloring paper is also made in the same way as the color reversible film, but the emulsion is made painted on a coated with baryta layer support made of paper. Appropriate procedures for Manufacture of photographic multilayer materials are in the process of dealing with color photography Extensive literature is described so that it does not need to be discussed in more detail.

Materials for multicolor photography developed by azine developers, i. H. aromatic triamines, developed into azine (phenazonium) dye images are described in US Pat. No. 2,486,440.

Materials for multicolor photography in which the dye images are azo dye images, can be described in the American patents ι 985,344 and 2,020,775 Process are produced.

The invention is illustrated by the following examples, to which, however, it is not limited, described in more detail.

example 1

A colored transparency about 5.7 X 5.7 cm in size was projected onto two sheets of white, opaque color reversal film approximately 3 inches by 5 inches copied, on both sides of which layers of gelatin were painted. The two exposed white ones Opaque pieces of color reversal film were first placed in a developer for 12 minutes at 20 ° C of the following composition:

p-monomethylaminophenol sulfate .... 3 g

Sodium sulfite 50 g

Hydroquinone 6 g

Sodium carbonate (monohydrate) .... 40 g

i \ * atrium thiocyanate 2 g

Potassium bromide 2 g _1χο

Water made up to 1 1

The developed Firm pieces were then ^c 3 minutes at 20 C in a 5 ° / o aqueous solution of Xatriumbisulfit treated it for 2 minutes in running water at 20 ⁰ C and washed with white light again exposed.

The re-exposed film was then 15 minutes Developed in color at 20 ° C in a developer of the following composition:

120 p-aminodiet'hylaniline hydrochloride ... 4 g

N ^ atrium sulfite 20 g

Hydroxylamine hydrochloride 2 g

Sodium carbonate 80 g

Potassium bromide ig

Water made up to 1 1

The film color developed was rinsed in running water for 4 minutes at 20 ⁰ C and cured for 5 minutes in a 3 ° / o aqueous solution of alum.

The cured film was washed in running water at 20 ° C for 5 minutes, and the washed one Film treated with a bleach bath of the following composition:

Dipotassium monosodium ferricyanide ... 100 g

Potassium bromide 15g

Disodium phosphate 40 g

Sodium bisulfate 25 g

Formalin (40 ¹ Vo) 20 cc

Water made up to 1 1

The bleached film was ^{washed for 5 minutes at 20 0} and then fixed for 5 minutes in a solution of the following composition:

Sodium thiosulfate 200 g

Borax 10 g

Water made up to 1 1

After fixing, the material was ^{washed in running water at 20 °} C. for 10 minutes.

»5 After completion of washing, a copy of which was dried, and the other for 3 minutes in an aqueous solution of 98 parts by weight of water and 2 parts by weight of N, N'-dimethylolurea rinsed and then dried.

Both copies, i.e. H. the treated and the untreated were then in an oven for 5 hours exposed to high humidity conditions. During this time the relative humidity was in the oven increasing from 56 to 100% at a temperature of 40 to 60 ° C. The copies were removed from the oven and allowed to cool to room temperature. The treated Color copy showed very slight yellowing. The color balance or the color matching of the however, the untreated color copy was complete with yellow staining that appeared everywhere spoiled, and also the density of the original yellow image was reduced. It was also found that the reverse side of the treated prints was also free of yellow-brown stains that had occurred on the untreated sample.

Example 2

Example 1 was repeated, but the humidity oven test was replaced by a storage test replaces ·. Both copies, i.e. H. the treated and the untreated, became in one ordinary filing cabinet kept for 8 months.

The test showed that the untreated print was brown-yellow in the white areas Showed discoloration. This brown-yellow discoloration occurred particularly on the back of the untreated Deduction. The images of the treated print showed no yellow discoloration, nor had it yellow-brown spots develop on the reverse side, as is the case with the untreated print Case was.

Example 3

Example 1 was repeated, but the color photographic material used consisted of one Color paper and the final rinse bath from a 2% solution of the reaction product N-ethyl urea and formaldehyde (N-methylolmethylene-bis-mono-ethyl urea) instead of the 2% N, N'-dimethylolurea solution. Of the Color proof dried without aftertreatment showed yellow spots everywhere after the experiment exposed in an oven with high humidity while the post-treated print showed no yellow staining.

Example 4

Example 1 was repeated, but the final rinse bath consisted of a 3% solution of the reaction product from N, N-dimethylurea and formaldehyde (N'-methylol-N, N-dimethylurea) instead of the 2% solution of N, N'-dimethylolurea. The untreated film showed after being exposed to high humidity in the oven, a yellow color everywhere Spotting, which completely spoiled the color balance, during the treatment The film showed no staining whatsoever.

The above examples are only intended to illustrate the invention, but the invention is based on them Examples not limited. Rather, changes can also be made to the procedure be by z. B. used equivalent substances and also changed the partial quantities of the substances used can be.

Claims (6)

PATENT CLAIMS: ι. Process for producing colored photographic images in a photographic Multicolor emulsion by exposing the emulsion to light and processing it into a color image with subsequent fixation and washing, characterized in that prevents the formation of stains after washing is by rinsing said photographic dye image with an aqueous solution, a water-soluble addition product in an amount preventing staining from formaldehyde and a urea of the following general formula O = C NR ₁ NH contains, in which R, R ₁ and R _{2 are} each hydrogen or a low molecular weight alkyl and R _{2 is} always hydrogen when both R and R _{1 are} low molecular weight alkyls. 2. The method according to claim i, characterized in that the addition product N-methylolurea is used. 3. The method according to claim 1, characterized in that that N, N'-dimethylolurea is used as the addition product. 4. The method according to claim 1, characterized characterized in that N-methylolmethylene-bis-monoethyl urea is used as the addition product will. 5. The method according to claim r, characterized in that the addition product N'-methylol-N, N-dimethylurea used will. 6. The method according to claim 1, characterized in that the addition product N-methylol-N, N'-dimethylurea used will. 5395 9.52