DE1772131A1 - Color photographic material with improved color rendering - Google Patents

Description

Color photographic material with improved color rendering

It is known that in color photographic multilayer materials with diffusion-proof embedded in the layers Color couplers in the color development especially at the points of stronger exposure and thus stronger development a · blackening of the colors occurs. The cause lies in that the coupling oxidation product of the color developer that occurs during color development - the diimide ion - does not It couples to dye directly at the place of its formation, but by diffusion it can move several meters away before it is consumed by reaction with color couplers or by side reactions. The consequence of these phenomena is that in Oxidation product arising from development in one layer diffuses into the immediately adjacent layer and closes there Dye can couple.

This undesirable phenomenon can be countered in several ways. For example, it is proposed to choose between the color coupler-containing Emulsion layers, thin gelatin separating layers containing color couplers to arrange. This method has the disadvantage that only the wrong partial image caused by one layer is avoided can be, if one does not arrange two such color coupler-containing gelatin layers one on top of the other, each of which is gelatin

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109808/0741 ■ ***> ° * iq _INal

Separating layer cen I-.uppier aer angreiizenuen Uup ^ lernaltigcr. Eauisionsschioht contains. The Vjriante ties procedure. ⁰ »is, however, technically more complex as a result of another watering process. It also increases the seed thickness of the paint film. Because of the disadvantages in processing, in particular, longer drying times and the deterioration in flatness and greater drying of the films, it is undesirable.

For the reasons mentioned last, the pure gelivoine separating layers which have been proposed for a long time are not a satisfactory solution to the problem either. If they are too thin, the effect on the improvement of the color separation is insufficient; if they are sufficiently thick, the disadvantages mentioned above occur, possibly also a reduction in sharpness due to the prolonged scattering of light.

It has also been suggested to use release liners to avoid the To use secondary images in which the diffusing color developer oxidation products be bound by conversion to colorless compounds, such as 1-phenyl-aiketotetrahydropyridazine and peri-naphthindone. However, these compounds are practically useless because their reaction rate with the color developer oxygenation product way too low iot. The same applies to _by substitution Diffusion-resistant reducing agents of the type des Hydroquinones and catechol, as already suggested .. order is. In contrast, compounds with are useful as colorless couplers activated methylene group in which a hydrogen atom is replaced by alkyl, Cycloalkyl, aryl or aralkyl is replaced. Your reactivity is but far less than that of color couplers and their representation requires greater effort

The density ues by diffusing out of the coupling color developer oxidation product in the neighboring bottom, the so-called secondary picture, is of course dependent on the reactivity and the concentration the color components contained in the primary, developing layer. However, it is not possible to use color components alone Qv and their reactivity to be selected, since in particular the course of absorption def resulting from them in addition to some of the image dyes other properties play a decisive role. Likewise is an increase in concentration a technical and also an economic one Limit set.

109801/0748 ~ ³ ~

BATH ORIGINAL

Pil "'do - ϊ -

It is, among other things, after v.ie before the purpose of the invention, such as 7orschv; .. r «- Production of color photographic images, especially in places Avoid strong exposure.

The invention is therefore based on the problem of overdiffusion of the color development process and the processing easy and economical way to avoid.

According to the invention, this object is achieved by applying a Gelatin intermediate layer, di · long-chain substituted o and thus diffuaionsfento alkyl oaer aralkyl-sulfinic acids containing at least between two of several emulsion layers. The 3c sulfinic acids can easily be found in higher concentrations in the form of their alkali salts When introduced into aqueous gelatin solutions, they give transparent properties Layers. I.'it diffusing in a color dev.ici.ler-Ox ^^ ntionsw-roJulrfc sit down to colorless sulfones u. · ::.

The application of the erfir-Iungsgemäien sulfinic acids is carried out by applying a gel: tinehaltigen LÜsung as an intermediate layer between EWT * farbkUj, J ₁ I-sustaining strength Enulsionsschicnteii. The ar. ζ uv; ο η ie ηα e!.! close and the thickness of the layer are given by the thickness iez I.econbildes u. \ d ^ c ^ n according to the reactivity and ilcr, sentration of the ki ^ ür ir. ^ en Eauisi-rs: ^ icht ·?:; determined v; ground. I-. cei'ien range 1 to 2 uu aiciie Iremi.rcliichte.i au.;. Lie ar ^:. '. C :. _r : e ca, 3ulfir.cuUi * e liec "- i-. general between 10 and %,% cor applied aolatinenienge.

The al.-yl- oaer aralkylQU-acidic acids can easily be prepared by reducing the corresponding sulfchloride, e.g. B. with Zini: - etaub. The alkyl or aryl-alkyl sulfonic acids or their chlorides with a longer ali: has a chain of melir rather than 1C C-Ac oaen are largely produced clinically for the Weischschnittel industry. So z. E.g. for the production of sulfinic acids uas so-called super sol are used, inter alia, the sulfociiloric represents a lararfin fraction with chain lengths of ^ C ^ o "Cig. For the use of the sulfinic acids according to the invention, uniform products are not necessary, eof Only a fraction with enough lance chains is selected. Aralkyl sulfo acids suitable as starting material are found among the so-called Igepals, which are derived from chlorinated carbon dioxide from the Fischer-Trcpsch synthesis chain.

10980r / 074l

P] j /|.28 - 4 -

lengths of C ^ ₀ - C ^ _{0 can be} obtained by condensation with benzene according to Friedel and Crafts and subsequent sulfurization. Uniform sulfinic acids for the purposes of the invention can be prepared from known compounds by analogous processes.

example

bin multi-layer copy material shows the following structure:

A blue-sensitive one containing yellow coupler is located on the support emulsion layer containing bromine-iodine-silver. Between this and the middle one, containing a cyan coupler and Eot sensitized silver chlorine emulsion layer lies a gelatin layer that contains p-cetyl-benzene-sulfinic acid. Between the middle red-sensitive and the top one, one Chlorosilver emulsion layer containing purple couplers and sensitized for green there is a p-cetyl-benzene-sulfinic acid containing gelatin layer.

! times of exposure and color development are much cleaner Colors are retained as with an identical material without the intermediate layers or with pure gelatin layers.

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109808/0749

BAD O * K5! NAL

Claims (1)

Patent claim Color photographic: multi-layer material with diffusion-proof Color couplers, characterized in that at least an intermediate gelatin layer between two of several emulsion layers is arranged, which contains diffusion-resistant alkyl or aralkyl sulfinic acids. PAH f, i -; - i-3 '-' I. Wed " 109808/0749