DE1815143A1 - Photographic images and methods of making them - Google Patents

Description

AGFA-GEVAERTAG ₁₈ 15U3

PATENT DEPARTMENT

LEVERKUSEN

Za / Po _{ic n}

'6, Dec.

Photographic forms' unu process su their ^ Ilerottillung

The invention relates to photographic media which also isinem Silver picture and one superimposed on the silver picture, which counteract the action of moisture are, as well as methods for stabilizing these BiUUc.

It is known to use a photographic material for the production of vesicle bilayers which has a layer of a binder in which light-decomposing compounds, for example diazo salts, are dispersed. If this material is exposed imagewise, the light-decomposing compound is decomposed in accordance with the exposed image, a gas being set free. The subsequent heating of the material causes the released gas to expand and create an image in the form of bubbles. The bubble image obtained in this way causes power scattering at the image areas, while the unexposed parts of the layer essentially let the incident through. A surface image therefore appears dark in transmitted light, but bright when viewed in reflected light.

Eb is also known to produce photographic images, by being in a binder in a manner known per se

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treated silver images with a compound that is decomposed by the silver images with the release of gas, and the gas expands to form a bubble image. In this way, photographic images are obtained which are in a layer, e.g. a gelatin layer, contain a silver image and a bubble image superimposed on the silver image.

The advantages of this process are that the images can be produced from silver salt, in particular silver halide, emulsion layers which have been compared have a relatively high sensitivity to light with the known materials for the production of vesicle images.

Furthermore, this process results in a significant increase in the pelvic force of the silver images produced in the photographic silver salt layers through the overlay achieved with the vesicle image. It is therefore possible to carry out the process from layers that are relatively low in silver go out and the silver images generated here with insufficient opacity due to superimposition with the vesicle image in To transfer images with normal opacity.

The combined silver vesicle images become hydrophilic Binders generally produced in gelatinous layers. Take in contact with water or in a humid atmosphere the layers of water on. They begin to swell and become soft so that they form the image as light scattering centers Blisters combine or even collapse into larger blisters escape the layer. Associated with this is a strong loss of eyelid density. The pronounced sensitivity to light is a considerable disadvantage, which is a practical one Application would prevent.

The invention is based on the object of methods for Stabilization of such photographic images Find the influence of moisture.

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There has now been made a method of making photographs Images found consisting of a silver image and a silver image superimposed vesicular image exist in a hydrophilic layer located on a layer support, by treating the silver image produced in the layer with a compound which decomposes through the silver image to form a vesicle image is, whereby a protective layer made of a hydrophobic water-impermeable is on the layer containing the finished image Applies binder.

Synthetic binders are used as binders for the hydrophobic protective layer or natural hydrophobic film-forming polymeric compounds are suitable. These polymers are allowed to be used on the photographic Properties of the underlying image-bearing layer exert no adverse influence. You should also can be cast in the usual way to form the thinnest water-impermeable layers possible.

Cellulose esters, e.g. cellulose acetate or butyrates, homo- or copolymers of olefinic unsaturations are suitable Monomers e.g. polyvinyl chloride, polyvinylidene chloride, polyvinyl ether, the ether component preferably being through Alkyl groups with up to 5 carbon atoms are formed e.g. polyvinyl isobutyl ether, Polymers of acrylic acid or methacrylic acid or derivatives thereof, e.g. polyacrylic acid esters, in particular with short-chain aliphatic alcohols with up to 5 carbon atoms e.g. polymers acrylic acid, methacrylic acid methyl ester, Contain acrylonitrile, methacrylonitrile or acrylamide in polymerized form. Have to be particularly useful Polyvinyl chloride or polyvinylidene chloride proved.

Silicone resins are also suitable, preferably those containing methyl or phenylsiloxane units.

The hydrophobic protective layer is created by appropriately spraying or pouring a solution of the hydrophobic film-forming Produced by means of the layer carrying the vesicle image. i * ls solvents are preferably such

• used that do not swell or dissolve the dis Eil ^^ Mcirt. Aliphatic ^ ketones such as acetone are suitable for ale or Buxanone, aromatic solvents such as benzene, toluene or xylene or aliphatic acid esters.

The production of the photographic image takes place in the in of the German patent specification. ... ... (P 15 97 512.9) described way.

The starting point here is light-sensitive silver salt layers, in particular silver halide emulsion layers. There are both silver chloride and silver bromide emulsions, or mixtures thereof, optionally containing silver iodide up to about May contain 10 moles $, is suitable. The emulsions can contain the silver halide in fine-grain or coarse-grain form such as in the case of ammonia emulsions. As a bandage Gelatine or other synthetic or natural film formers or mixtures thereof can be used, for example. the Materials with such emulsion layers are commonly used imagewise exposed, developed and fixed.

The silver images obtained in this way are treated with a compound which is decomposed on the silver image to form gaseous products. Hydrogen peroxide (H ₂ O ₂ ) is particularly suitable.

Treatment with the gas bubble-forming compound, in particular with hydrogen peroxide can be done in a variety of ways. You can z.3. which the developed silver image A layer containing a new sole containing hydrogen peroxide is coated with a solution of polyvinyl chloride, for example in butanone- (2), which contains hydrogen peroxide. After coating is dried and heated by the Bubbles generated. The developed photographic layer k & vu can also be treated with a hydrogen peroxide solution such as an alcoholic solution.

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Treatment of the photographic layer with vaporous hydrogen peroxide is most favorable. After a period of about 30 seconds with a saturated hydrogen peroxide vapor, the layer has absorbed sufficient hydrogen peroxide. Of course, the exposure time depends on the exposure temperature and the concentration of the hydrogen peroxide vapor. For example, temperatures from 50 to 90 ^υ are suitable.

In a preferred embodiment, the developed silver halide emulsion layer after treatment with the Hydrogen peroxide vapor exposed to a water vapor atmosphere of about 50-90 ° for about 1-5 seconds. The in the case of treatment with hydrogen peroxide alone, a reinforcing effect which can be achieved only relatively slowly.

It has proven to be even cheaper to use hydrogen peroxide exposed, treated, developed photographic layer to an alkaline water vapor atmosphere Suitable for pH values between 8 and 12. This can easily be achieved by adding small amounts of ammonia to the water vapor or vapors of volatile amines are added. The concentration of the alkaline additives is not critical in general, amounts between 0.1-5 percent by volume, preferably about 0.3-1 percent by volume, have proven to be sufficient proven.

The formation of the visible bubbles takes place through the expansion of the primarily formed gaseous reaction products. This is achieved by heating to! Temperatures between 60 and 100 °. The formation of the vesicles is supported by a slight softening of the layer, e.g. by moistening. This effect is achieved by the treatment with steam described above. A special one arises here favorable form of a leaflet. The vesicles are very small and the images formed from it therefore have a special one high density.

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Betspiel;

A photographic material having a silver bromide emulsion layer on a cellulose triacetate support, which, based on the total silver halide, contains 3.5 M0I96 silver iodide, wii. Exposed eyelid. Afterward is developed in a developer of the following composition:

Hydroquinone 3 g p-methylaminophenol 1 g Sodium sulfite 13 g sodium 26 g Potassium bromide 1 g on 1 1 water

Finally, as usual, with an aqueous sodium thiosulphate bath fixed and dried.

A negative image of the original is obtained, but it is only weakly covered and cannot be copied using conventional methods is.

Processing is now carried out as follows:

1) 30 seconds treatment with saturated hydrogen peroxide vapor at 7O ⁰ J

2) 3 seconds - exposure to a steam atmosphere of 75 ^° C

An extraordinarily large amplification effect occurs immediately <ναί \ whereby, for example, a digit with a density of 0.3 of the initial negative is increased to around 1.9.

The picture sample above is cut into 5 strips and the individual strips are treated as follows:

Sample 1: remains untreated for comparison.

Sample 2: The picture is immersed in a 70% by weight solution of polyvinyl chloride in butanone- (2). You let them

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excess solution will drain off and dry. Γ .. The protective layer has a density of around 20 µm.

Sample 3: It is with a 50 wt .- # solution of polyvinylidene chloride treated in butanone- (2) as in sample 2.

Sample 4: A 50% strength by weight solution of a polymethylsiloxane resin in xylene is mixed in a volume ratio of 1: 1 with butanone- (2) and this mixture as in Sample 2 described applied to the image-bearing layer.

Sample 5: In the same way, "·· a Layer of polyaryl acid methyl ester applied

The samples treated in this way are bathed in water at 20.degree. C. In the case of the uncoated sample 1, the image density is already clearly noticeable after a few minutes. With * <»· ■ ^ robe?» 2-5, on the other hand, no changes in the image density can be detected even after 30 minutes of handling.

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Claims (4)

Patent claims: 1. Photographic images, consisting of a silver image and a bubble image superimposed on the silver image in one hydrophilic layer, characterized in that a water-impermeable layer over the layer carrying the vesicle image hydrophobic protective layer is arranged. 2. Process for the production of photographic images consisting of a silver image and a superimposed on the silver image Vesicular image exist in a hydrophilic layer located on a substrate, by treating the in the Layer produced silver image with a compound that is decomposed by the silver image to form a bubble image, characterized in that the The finished image-containing layer applies a protective layer made of a hydrophobic water-impermeable binder. 3. The method according to claim 2, characterized in that the image-bearing layer is coated with a protective layer made of polyvinyl chloride or polyvinylidene chloride. 4. The method according to claim 2, characterized in that the image layer is coated with a protective layer made of a silicone resin. AQ 445 - 8 - 00 9 8 27/1629