DE1295366B - Use of development nuclei made with modified gelatin for the physical development of silver images - Google Patents

Description

The invention relates to the use of with Finally, photographic materials,

modified gelatin produced development- the zinc sulfide nuclei produced according to the invention germinate for the physical development of silver containing and that for silver salt diffusion transfer images. method of the US Pat. No. 3,020,155

It is known e.g. B. from the book by Mees and 5 known types are determined, such Aufzeich-J am es, "The Theory of the Photographic Process," nung materials that have been used so far Published by The Macmillan Company, New York, 1966, common zinc sulfide seeds have been prepared over-3. Edition, p. 329 to 331, for the production of silver lay because they are physically to images through physical development develop developer images of higher density, To use solutions which, in addition to a reduc- io The manufacture of a with tetrachloro-p-benzotionic agent a soluble silver salt and additives entquinone-modified gelatin can, for example with which the pH value and the silver ions take place according to the following procedure: the concentration of the developer solution is adjusted 250 g of a 10% bone gelatin solution

will. '' * ■ comparable to at 4O ⁰ C with 650ml of distilled water

From these solutions, 15 is thinned during development. The gelatin solution is then 5 g of tetra silver on development nuclei, e.g. from zinc chloro-p-benzoquinone added, whereupon the mixture sulfide, lead sulfide, nickel sulfide, silver selenide, is stirred for 4 hours at room temperature, loidal gold or colloidal silver, the mixture is then filtered, whereupon the cloudy dejected. In a modified version the filtrate is centrifuged, producing a clear, red form of physical development, which is obtained as a solution which is represented by a yellow so-called »prefectural physical development residue is decanted and mixed with distilled water lung «(cf. the given literature - is diluted to a total volume of $ 00 ml, place, in particular p. 326), the silver halide is produced using a

not dissolved out first, but a disfigured gelatine can e.g. B. zinc sulfide nuclei Used winding solution, which is a strong silver 25 made in the following way: halide solvents such as sodium thiosulfate, the gel prepared in the manner described

holds, which dissolves the halide to the extent that tin solution is at 40 ⁰ C with a solution of which the development proceeds. 1.26 g of anhydrous sodium sulfite in 74 ml of distilled

The disadvantage of the previously known developing system is water and then with 2.65 ml of 0.944 n-sodium nuclei is that their activity does not particularly mix sulfide solution. Immediately after the addition is great. the sodium sulfide solution becomes a solution of 2.60 ml

The object of the invention is to develop nuclei 0.99 n-zinc nitrate in 270 ml of water in 4 minutes and allowed to run into the mixture for 30 seconds for the physical development of silver images, indicate which one is being stirred at the same time during development. To this develop particularly high levels of activity. 35 way a zinc sulfide sol is formed in gelatin,

It has been found that development can be solidified by quenching and then germinate the required properties, then noodles and washed with water if it is no longer possible to produce them, as before, to remove the water-soluble salts, usual, simple gelatin as the dispersion medium. The procedure described can be analogous

but rather one with tetrachloro-p-benzoquinone 4 ° on the production of the other metallic demodified Gelatme used. development germs are transferred.

The invention therefore relates to the production of colloidal metals, such as

Use of physical defected with tetrachloro-p-benzoquinone modi-silver and gold Gelatin as a dispersion medium in the development germination can after the for the production preparation of dispersions of sulfides, selenides 45 by Carey Lea-Silber at Weiser, »Colloidal EIe- or tellurides of heavy metals or metallements ”, p. 119, New York (1933) Lischem gold or silver existing development process take place, which as a reducing agent germinate used for the physical development of silver dextrin. It is only necessary to illustrate the used gelatin by the inventively used

The invention achieves that by replacing the modified gelatin, physical development of silver images of higher ". · - \ *

Density can be produced as the development Example 1

lungskeime a larger number of active or with the prepared in the manner described

of more active centers for the physical zinc sulfide sol as well as one in a corresponding manner, Show development than those produced in an untreated 55 but with unmodified gelatin Gelatin dispersed development nuclei. Zinc sulfide sol were layer supports made of cellulose

As a particularly advantageous use of triacetate films and polyethylene terephthalate films of sulfide development nuclei for the production of photo-coated in such a way that on about 0.09 m ^{2 of} support surface of graphic recording materials, 296 mg of gelatin and 1.44 mg of zinc sulfide were used, which were used for the production of directly positive BiI- ^6o The coated films were then at 25 ° C in which are determined by physical development. a physical developer of the following e.g. B. developed according to the method of the invention composition: produced zinc sulfide development nuclei of a photo ₄ _Amino-3-methyl-N-ethyl-N-

graphic silver halide emulsion layer tensile (/ ^ o _X yethyl) aniline 0.5 g

sets, positive images of higher £ 65 ' ^] " ""f

Density obtained than when using zinc sulfide- η ^, υ ^ Ό 1.274 g

germinate with normal untreated gelatin potassium triphosphate H ₂ O 50.0 g

were manufactured. [Ag ⁺ ] IX ΙΟ "* ² moles

Made up to 1000 ml with water, adjusted the _{pH to 12.0 with 6 nH 2} SO _4.

The free silver ion concentration [Ag *] of the developer containing a total of 5 × 10 ^-3 mol / liter of silver chloride was brought to the specified value by adding sodium thiosulfate.

The following table shows the mg of silver per 0.09 m ^{2 of support} surface, which were developed after 40 and 80 minutes of development:

The emulsion layer was then coated with a layer of a zinc sulfide sol prepared as described, which contained 560 mg of gelatin and 0.2 mg of colloidal zinc sulfide per 0.09 m ^{2 of support surface.} The recording material obtained was exposed for one second in a conventional sensitometer and developed in a developer of the following composition:

Modified after the
Invention)

Not modified

Used gelatin

in mg Ag
40 minutes 80 minutes

55
30th

263
161

The results obtained indicate the greater activity of those using the modified ones Gelatin produced development nuclei.

Example 2

This example describes the use of the development nuclei prepared as described for Preparation of a photographic recording material of the type described in U.S. Patent 2,861,885 known type. The recording materials known from US Pat. No. 2,861,885 consist according to an advantageous embodiment of a layer support, one applied thereon Silver halide emulsion layer and a development nuclei disposed on the silver halide emulsion layer for the physical development layer contained. The recording materials of this type can be carried out in the context of the process known from US Pat. No. 2,861,885, the practically represents a further development of the known silver salt transfer process for production use of images. In this process, the recording material is processed according to the image Exposure developed with a solution containing a silver halide developer compound and a Contains silver halide solvents. This makes the silver halide emulsion layer negative The silver image has a relatively low hiding power and a positive one in the layer containing development nuclei Produces a silver image with a relatively high opacity. When viewed together, both partial images deliver, i. H. at The partial images are superimposed, a sharp image of the object to be imaged.

A layer of a gelatin-silver bromide iodide emulsion was applied to a cellulose acetate substrate in such a way that 100 mg of silver and 230 mg of gelatin were accounted for ^{on about 0.09 m 2 of substrate area.} Above

Water at 50 ° C 500 ml

N-methyl-p-aminophenol sulfate 3.1 g

Sodium sulfite, dehydrated 45.0 g

Hydroquinone 12.0 g

Sodium carbonate, dehydrated, 67.5 g

Potassium bromide 1.9 g

Sodium thiosulphate 4 g

Made up to 1 liter with water.

ao The developed recording material was then rinsed, then fixed in a sodium thiosulfate bath for 2 minutes, washed and dried. The silver halide emulsion layer was thus chemically developed

«5 exposed areas of the layer corresponding negative image of low contrast and a positive one in the layer containing development nuclei Obtained high opacity silver image. Containing the positive silver image of the development nuclei Layer had a considerably greater density than an image formed under the same conditions, the was produced starting from a material which does not contain any zinc sulfide development nuclei modified according to the invention contained.

Thus if zinc sulfide development nuclei dispersed in a gelatin modified with tetrachloro-p-benzoquinone in that over the silver bromide iodide emulsion layer of the photographic material applied layer is used between the adjoining The differentiation obtained in negative and positive areas of the image is much better than when not modified gelatin dispersed zinc sulfide development nuclei in a layer over the silver bromide iodide emulsion layer of the recording material are arranged.

Claims (1)

Claim: Use of gelatin modified with tetrachloro-p-benzoquinone as a dispersion medium in the production of dispersions of sulfides, selenides or tellurides of heavy metals or metallic gold or Silver existing development nuclei for the physical development of silver images.