DE1547987A1 - Photographic material - Google Patents

Description

Photographic material

The invention relates to the production of photographic images and to the photographic images used therein Materials.

With the ever increasing price of silver, it has become important in recent years to reduce the amount of silver (as halogen silver) used in photographic material. It is an object of the invention to provide a method and materials for the formation of photographic images or records wherein a given image density is achieved with reduced silver consumption.

According to one feature of the invention, a method for

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Photographic reproduction or reproduction created in which photographic material is made from a substrate-r layer on which a layer is applied in the form of a coating is, the halogen over into a, curable binder as well as a heat-sensitive ^ dye-generating mixture and includes a silver halide stripper, which is in development formed oxidation product harden the hardenable binder can, picture by picture, exposed on this '.', else in that

P photographic material formed by latent silver image Treatment of the material with an aqueous alkali solution, whereby those parts of the layer containing halogen silver which are in contact with the oxidized developer, are hardened, the non-hardened parts of this layer are removed and then the photosraphic:.: aterial heated, thereby forming a dye image which by development formed silo image reinforced.

In another embodiment according to the invention

. there is the heat-sensitive, dye-producing mixture in a layer adjacent to the layer containing the halide silver and is also contained in a curable binder. It can be seen that by that the effective density (net density) of the image through both the silver and through the dye is achieved, the presence of the dye image reduces the amount of silver that would otherwise be used to achieve the .The same density would be required.

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According to a further feature of the invention is a new photographic material provided with a backing layer on which a layer is applied in the form of a coating, the halogen silver salts · in a curable binder as well as a heat-sensitive, dye-generating mixture and a halide silver developer, the oxidation product of which the hardenable binder formed during development can harden. In a further Ausfährunesforni this. "." Features of the invention is where the heat-sensitive, dye-producing area is located Mixture in one of the Kalop: er.silver.T.uls-ion layer adjacent and contained in a curable binder. Splint.

Preferably this consists of the Ralofcensilbers tailsion layer and in the one that produces the color substance iiischune; containing layer used hKrtcsre rir.de.:.ituel, if it is present, made of = gelatin. But ker.n-? N others too curable binders such as polyvinyl alcohol and modified Fo Iy a cry la.τ. id, verv ends be (aie british Patent specification 967 208 describes a sreeic-neres .r-cdified Polyacrylamide).

Preferably the ir.tv/ickler is in the Ilalofren silver containing Shift exist. . ~ n; however, he can also ir heat-sensitive, dye-producing. ".: ischur Layer, if present, in the photographic material to be available.

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BATH ORIGINAL

Under heat-sensitive, dye-producing mixture is to be understood as a mixture containing a dye precursor ·. together with a coupler and a water-insoluble, fusible solid. Which melts at 6o-200 ° C., which fusible solids in the molten state can dissolve either the dye precursor or the coupler or both. if the mixture is heated and the fusible solid melts, the coupler is thus enabled with the "Dye precursors to form a stable dye couple. Examples of suitable heat-sensitive, dye * -generating "mixtures are given in the British patent application. 3243/64. In this patent application a heat-sensitive, dye-generating mixture described, the a triazene dye base of the following general formula (I)

R ₁ -NN- K

in which R ₁ and R_ aryl or substituted aryl groups and R _{2 are} methyl or ethyl, an azo coupler compound which couples with the triazene, and a solid melting between 6o ° and 15o ° C, which in the molten state is a solvent for the triazene base and represents the azo coupling compound. Suitable azo coupling compounds are resorcinol, phylonrglucin, naphthol or ß-ketonic acid ester anilide. Suitable, between

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Solids melting at 60 ° and 150 ° C are acetanilide, benzoin and furoin. Other suitable thermosensitive dye-generating agents Mixtures are described in British Patent 989,382. However, those in the UK patent application have 324-3 / 64 and British Patent 989 382 fusible pesticides described each have melting points below 150 ° C. Other fusible solids with higher Melting points can be used according to the invention, see above e.g. benzanilide. Other suitable blends are disclosed in U.S. Patent 2,663,654.

The preferred developer is hydroquinone, but can other tanning or tanning developers, such as catechol or pyrogallol, can also be used.

In another embodiment of the invention -ein Combination of developers used, the oxidation products of which have a caustic effect. An example of such a combination from developers is hydroquinone and i-phenyl-3-pyrazolidinone. .If the developer is on any layer other than If the layer containing halogen silver is present, it will diffuse into the halogen silver immediately after plating containing layer.

The exposed material can be treated with the aqueous alkali solution by placing the material in the solution immersed, or the aqueous alkali solution can be

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zenaufbringungseinrichtung or similar device to be applied to the "exposed material. Although the material any alkali solution may be used to effect the development, is the preferred alkali from sodium hydroxide. Preferably, is aborted, the processing step for a period of time (previously determined for the particular material) by the material is immersed in an acid bath, for example an aqueous acetic acid stop bath.

During the development stage, the exposed silver halide is reduced to silver and the developer is oxidized. Its oxidation product hardens the binder associated with the developed silver and also diffuses into the adjacent layer containing the heat-sensitive, dye-generating mixture, if that layer is also present. It has been found that the oxidized developer product diffuses directly upwards into this adjacent layer when this layer is above the calogen silver emulsion layer or diffuses directly downwards when this layer is below the halosilver emulsion layer. There is only a very slight lateral diffusion of the oxidized developer product, so that if the layer containing the heat-sensitive mixture is present, it will be hardened by the diffusion developer-oxidized product in exactly the same areas as the halogen-coated layer. After developing and hardening, the halogen silver contains-

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the layer and the other layer, if this is vorhanden-, the non-hardened parts of the two layers are removed. This can be achieved by washing the material in hot water or, if gelatin is used as a binder in both layers, the non-hardened parts of the two layers can be removed by removing the material in dipping a gelatin denaturant such as a solution of sodium salicylate.

After the washing process, a relief image is created containing silver in the hardened binder, and if an adjacent layer is present, a relief image of this adjacent layer is formed, which is the silver relief image corresponds exactly. The fömaterial that this relief silver picture contains, is then heated, whereby the warmth-sensitive, Dye-generating mixture for the formation of a dye is initiated. In this way, a dye image is created that intensifies the silver image.

The method according to the invention is illustrated by the drawing, wherein

Fig. 1 shows the material for use ee.r. according to the invention prior to treatment;

Pig. 2, 5 and 4 the different stages of treatment of this Show materials;

Figure 5 shows the final material after exposure and treatment shows.

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According to F, ig. 1 comprises a gelatin halide silver emulsion ■ ^; Layer 1 also includes hydroquinone and a heat sensitive, coloring, « _% substance-producing mixture. This emulsion layer 1 is applied to a base 2 in the form of a coating. The meaning of the reference numbers 1 and 2 remains the same in all the following figures. According to FIG. 2, the halogen silver emulsion layer 1 ′ is replaced by λ

Transparent
a - negative DtH * efo-g4c-ei4; (transparency) 5 by means of a · 'V lamp. 4. exposed.

According to Fig. 3, the emulsion layer 1 is shown, which is indicated by '.. Treatment with an alkali solution has been developed. the Areas 5 show that the halogen silver is reduced to form a positive silver image, the unexposed ', ■■. Areas6 left behind. . · '

According to Fig. 4-, the emulsion layer 1 is shown after ■ the unexposed, uncured parts, which were designated 6 above, are removed by washing in hot water '"· ■ were, the silver image areas 5 remaining in relief. ..

According to Fig. 5, the material is shown after heating. ^ The areas labeled 5 according to FIG. 4 are now labeled 7 and are darker here to show that a dye image has actually been formed in these areas, which reinforces the previously formed .silver image.

The normal coating weight of the halogen silver emulsion ma-

2 terials is in the range of 50-80 mg / dm. When using the

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\ In accordance with the invention, it is possible to use this over.

pull weight. to decrease to 2-15 mg / dm, though. Pictures of the the same density can be obtained, thereby achieving a great saving in the amount of silver used.

The silver halide emulsions used according to the invention can be optically and chemically sensitized in the usual way be. * ', "," ■ - · .-

The invention is illustrated below by way of example illustrated in more detail. ·

■ * _ · - ■. Example , '

12g ^1,4-l _/ 4 "-Tolylthio-2 ^f 5 ^l ~ dimethQxyphenyl-3-methyl-3,4 ^l -toluenesulfonyltriazene, 28 g benzanilide, 120 ml 5% aqueous gelatin and 4 drops of an antifoam (Silcolapse 437 , a product of ICI Ltd.) vmrden together for 60 hours at about 35 C (95 SO in a ball mill. A second dispersion containing 8 g of 2-hydroxy-3-. naphthoic anilide (Brenthoi AS), 28 g of benzanilide, 120 ml of 5% aqueous gelatin and 4 drops of an anti-foaming agent (Silcolapse) were also ground in a ball mill for 60 hours at about 35 ° C. (95 ° C.).

62.5 ml of each of these two dispersions were mixed with 208 ml of 5% aqueous gelatin, 40.5 ml of 5% aqueous gelatin Hydroquinone, 37.5 ml of a sensitive JOdbromemulsion

90-988 1/1405

- Ίο -

mixes and in the form of a coating on a flexible, translucent Pad with a coating weight of 11 mg

Silver, applied to each dm. _

When the coating was dry, it was behind an optical wedge with a standard 735 source for 1/5 second Meters of candles exposed and treated in the following manner:

1) The coating was applied at a speed of about 2.5 cm (1 inch) / sec through a. Roller application device guided, which, on the emulsion surface, apply a 5? 4 aqueous Sodium hydroxide solution applied. - *

2) After developing for 10 seconds, the Coating for 10 seconds in a stop bath of a 5% aqueous solution Acetic acid immersed to prevent further development and further pickling or tanning.

3) The undeveloped and non-pickled areas of the Coatings were removed by immersion in hot water (at least 5o C) and the coating was dried. In this At the 2nd stage, the picture consisted only of silver and pickled gelatin.

4-) Finally the coating became one for 5 seconds Subjected to a temperature of about 16o C by sandwiching it between two heated metal plates the formation of a dense blue dye image by the reaction of triazene and 2-hydroxy-3-naphthonic anilide (Brenthol) caused »

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The following are the maximum densities and contrast values of the image before and after the final dye-forming heat treatment specified: '

• ■

Contrast ' Dmax

before 3.75 1.25 after 11.5 3.5

A piece of the coating which had been fixed, washed, dried and subjected to the same heat treatment as in Step M was found to have an optical density of 1.9o.

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Claims (1)

rat ^ nt'in T-) Photographisah ^ s ^ torial, thereby identifying, it as tit ore jig on a: nterLuj & cch.icht either a hardenable ¹ binding agent! Layer. ,, aie Halcj; noil cer as well as, a warm er-p find - borrowed ,, dye zoujundc!. 'Ischun. ;; and a halogen silver developer,: whose hot .1 ^ r 2:; -: v; icklun / T formed: Gxydatioiasprodittfct the hardenable binary: ^ it ~ el r.'lrters k ^ nK ,. ur ^ f'aSt., or two layers of a hiirtbaro :; BinuO ittols ^ ,, wherein one; ialo £ en.silter IMD -findliehe the other one would Ger ^ _^; color-producing graphics. contains ^ tra ^ t, - v / c with in, at least one of these- binder layers an alcalgen.cilb.erenr. '/ ickler is present, de ^ seja; tea of the development formed τ es Ozjdaticnapr-o-dukt the hardenable binding agent can harden .. 2 / Photographischus "Sep.ruduktl'cnsverfahren: for the generation of a xarbstoifVeratkten Eilber picture using, the photographic,!. 'Aterials ger. &L.;, Claim T ,, characterized. ,, that one is the photograph is before ; erial picture for image, the latent image formed on this, e · \ 7eia & in. Alkali solution developed ,,. The, non-hardened parts, of the hardenable binder removed'and finally the photographis before - Mä-fce rial heatedv - wqdtir Ch- eiss' PariasnioAiild 'is formed, "which, the ^ formed by' development reinforced. ORIGINAL