DE2326334B2 - Photographic material with an antistatic, electrically conductive metal layer - Google Patents

Description

The invention relates to a photographic material with a hydrophobic dielectric layer support, liner antistatic, electrically conductive metallic layer with a surface resistance of less than 10'- 'ohms per square caused by oxidation η a comparatively less conductive layer 'transfer comparatively lower optical density " is, at least one radiation-sensitive Layer and optionally adhesive, intermediate and / or cover layers.

It is known that in photographic recording materials with at least one radiation-sensitive emulsion layer which is deposited on a dielectric Layer support is arranged, the accumulation of static charges on the layer support undesirable Effects can result if a discharge occurs, the undesirable effects usually being in consist of obscuring the emulsion layer in the vicinity of the discharge. The accumulation Static charges have a particularly disadvantageous effect in the case of roll films which do not have protective gelatin layers or have intermediate paper layers, which is often the case with roll films that contain a should have particularly low weight, or in the case of roll films, for a fast development process are determined.

It is therefore well known, e.g. B. from the book by P. Glafkides, "Photographic Chemistry", Verlag Fountain Press, London, Volume I, 1958, Seile 473, to make photographic recording materials antistatic by adding antistatic organic compounds or inorganic salts.

It is also known e.g. B. from GB-PS i 09 659, thin to dissipate electrostatic charges or to prevent the formation of electrostatic charges on dielectric photographic substrates

JO metal layers to be used, which one is sufficient have high conductivity to prevent the build-up of high localized static charges. Opposite to the use of organic compounds and inorganic salts have such thin

i'y metal layers have two major advantages. On the one hand, their antistatic effective wedge is considerably greater and, on the other hand, their effectiveness, in contrast to the effectiveness of organic compounds and inorganic salts, is independent of moisture, so that

κι they can develop their effect even in an extremely dry atmosphere. The disadvantage of the metallic Antistatic layers, however, is that when they are in the form of thin layers of a thickness of less than a few 100 Α units are used,

• r> easily oxidized during storage, so their Conductivity and thus its antistatic properties are quickly lost. In contrast, it becomes a such a metal layer is produced in a thickness sufficient to cause a decrease in conductivity

Avoid w, this increased thickness leads to an undesirable increase in optical density. Of It has also been shown that some metals with photographic layers under a fog Metals and desensitization of the layers react

Vt and that some metals, ζ. B. bismuth and manganese can react in an undesirable manner with the layer supports. Another disadvantage of using metallic, antistatic layers is that, if a layer support is freshly on it

W) coiled down antistatic metal layer, the metal layer often adheres to the other side of the substrate, so that the metal layer too can lead to blocking, d. H. a prevention of trouble-free unwinding of the film support.

h ^r i whereby the metal layer can often be transferred from one side of the substrate to the other side during unwinding.

Ks is also known to be the most diverse

optical article, ζ. I). Lenses and l.insensysieme. Windows and windshields, made using metal and melal halide sharks. For example, it is known from US-PS 33 30 681, the reflection of plastic optical Objects by using a metal layer and a metal halide layer. the end üer US-PS 28 "32 41" 3 it is also known by Intimate mixing of metals and metal. 'Dialogei': - the layers on silica or silicate surfaces / u that have a desired conductivity wedge and adhere to the surfaces.

The object of the invention was to provide a photographic recording material with an electrostatic discharge Specify charges specific metal layer, whose metal layer does not see (a) during storage oxidized, however (b) in the development of the material by oxidation into a layer of comparatively low density is transferred.

The invention was based on the knowledge that the All tasks are solved with one system that consists of at least two layers, namely at least one electrically conductive Metal layer which is transformed into a less conductive, less optically dense state through oxidation can be and a protective metal fluoride layer, which the oxidation of the electrically conductive Can prevent or at least reduce layer in the atmosphere and which for oxidizing aqueous Solutions are permeable and thus enable the oxidation of the electrically conductive layer.

The subject of the invention is thus a photographic one Material with a hydrophobic dielectric layer support, an antistatic, electrically conductive metal layer with a surface resistance of less than 10'- 'ohms per square passing through Oxidation into a comparatively less conductive layer of a comparatively less optical one Density can be transferred, at least one radiation-sensitive layer and, if necessary, adhesive, intermediate and / or cover layers, which is characterized. that at least the support remote side of the electrically conductive layer with a permeable for oxidizing aqueous solutions Protective layer of magnesium, calcium, barium, cerium or sodium aluminum fluoride layer covered is.

Sodium aluminum fluoride is also known under the name Cryolite (NajAIFt,).

The electrically conductive layer should preferably have a surface ^{resistance of less than 10 8} ohms per square.

The protective layer consisting of a metal fluoride layer prevents oxidation of the conductive ones Metal layer during storage of the material until it is used, but is for aqueous oxidizing solutions permeable, so that the electrically conductive layer by oxidation in an optically less dense state can be converted if the photographic material in a usual aqueous photographic working solution is treated, for example a bleach and / or break bath or a developing or fixing solution.

It has been shown that not only bleaching solutions have an oxidizing effect, but also unbreaking baths as well as fixing and developer solutions. Obviously, the oxidation of the electrically conductive Metal layer through the in tier, solutions and butlers existing llydroxyliunen initiated. In case of Use of aluminum shutters, for example occur as oxidation products aluminum ions (AK) ..) on.

The invention thus enables photographic materials to be prepared prior to accumulation localized static charges are protected when using the photographic materials after the developing process, photographic images can be obtained which are in quality are not impaired by the high optical density of metallic, antistatic layers.

The electrically conductive layer can consist of any electrically conductive metal, which unit is brought into contact with an aqueous photographic working solution for photosensitive Emulsion layer or the photosensitive !! Emulsion layers can be converted into an optically less dense state by oxidation. It is irrelevant whether the oxidation product itself is a has lower optical density or whether the reduction the optical density of the layer is achieved in that the oxidation product by the action of photographic working solution is dissolved or at least partially goes into solution.

Manganese, Bismuth, copper, aluminum and silver were found to be easily oxidized to a lesser state optical density can be converted if they are in the form of thin layers. Since the electric conductive layer in all cases, e.g. IJ. when the photographic material is wound through the The protective layer is separated from the radiation-sensitive colloid layer. can be used to generate the conductive layer metals are also used, which adversely affect the colloid layer would react and especially those metals that. if they were used alone, for a disguise or desensitization of the radiation-sensitive colloidal hichi.

According to the invention it is also possible to have a second protective layer between the substrate and the electrical to arrange conductive layer. In this case, the electrically conductive layer can be produced a metal can also be used, which, if it were applied alone or directly to the substrate, with would react to this. For example, metals can be used to produce the electrically conductive layer how manganese and bismuth are used, although these two metals are known to be photosensitive Silver halide emulsions are able to obscure when they are in direct contact with the corresponding Emulsion layers are brought, and which in an undesirable manner with built up from polymers Film substrates react when applied directly to them.

In order to ensure adequate protection against the accumulation of static electricity, it has been found necessary that the electrically conductive layer has a surface ^{resistance of less than 10 1} - ohms per square. Preferably, it should have a resistivity of less than IO ^H ohms per square.

To ensure that a surface ^{resistance of less than 10 s} ohms per square is achieved everywhere, it has proven to be advantageous if the conductive layer covers a total surface area.

stood by less tils 10 "'ohms per square. With electrically conductive layers having a surface resistance of less than 10 "ohms per square Particularly uniform photographic reproductions can be obtained without optical changes which can be traced back to localized discharges of electrostatic charges are.

The surface resistance of the layers can by measuring the resistance between two parallel electrodes of the same length, whose distance from each other corresponds to their length, determine! will. (See the book by Maissei and Gong “Handbook of Thin Film Technology ", McGraw-Hill Verlag (1970), pages 13-5 to 13-7.) Since an increase in the length of the electrodes leads to a decrease in resistance, and by an amount equal to the amount by which the surface contradicts itself through enlargement the distance between the electrodes has been increased by a corresponding increment, it is evident that that the length of the electrode and the distance between the electrodes are immaterial as long as they are the same. Consequently is the surface resistance, expressed in ohms per square, a contradiction, determined for the special case by adding the length of the electrode and the distance between the electrodes identical and consequently are mutually canceling parameters.

The electrically conductive metal layer is preferred not thicker than is necessary to achieve the desired conductive wedge properties. Such Conductivities leave layers of a thickness below 100 "A, preferably below 50" A. The reason that the layer thickness of the electrical conductive layer should be limited, depending on the im Individual cases used special metal, based on the fact that the electrically conductive metal and / or one or more of its oxidation products can enter the aqueous pholographic Arbcilslösung, the both / ur development of the radiation-sensitive Colloids and at the same time to reduce the optical density of the conductive layer can be used. By limiting the thickness of the electrically conductive layers, the amount of Metal that is in the work or development solution can occur, limited and the effectiveness and lifespan of the work or development solution extended accordingly. Although the thickness of the electrically conductive layer is well over 100 Å can, depending on the metal used in the individual case and / or the resulting oxidation product, the photographic working solutions can occur, as well as the volume and the desired purity of the Work solution, it has been shown that as a rule Layer thicknesses of over 1000 Λ are not required or appropriate.

It was surprising to note that end of the slot to the solution animal of the invention, the underlying object of layers can be used which are capable / u schülzen the electrically conductive layers from oxidation during storage and use and which ties further oxidation animal electrically leilfähigen layers by transferring the same In an optically less dense norm in the course of the photographic development process was made possible by means of aqueous solutions.

The protective layers consisting of ι. \ Ί · \ ^ mentioned lluunilcu should preferably have a Duke \ oii less than 500A, in particular a thickness of less than 50A, especially if a storage of the photographic drawing material before development or treatment in An aqueous oxidizing solution is to be expected. The density of the metal fluoride layers can increase somewhat when stored. The use of Melallfliioridschich th a layer thickness of less than 50 Λ has proven to be particularly advantageous, which can easily be penetrated by aqueous oxidizing solutions in all grooves. If protective melali halide layers remain in the developed photographic material, these advantageously have optical densities of less than 0.5 and situ, preferably practically transparent, ti. H. have an optical density of less than 0.01. In halls in which the protective layer is completely learned in the course of the photographic development process, which is generally the groove, the optical density of the protective layer does not affect the developed photographic material.

According to one embodiment of the invention, tlit electrically conductive layer directly on the dielectric Layer carrier bound and the protective layer is located directly on the electrically conductive layer. 1 In this case, the layer support protects a surface of the electrically conductive layer, whereas dit Protective layer protects the other surface of the electrically conductive layer.

In the grooves in which the substrate itself fii Oxidizing agent is permeable and / or in the grooves in which animal forms the electrically conductive layer Substance with the visual carrier material is able to react, it has proven to be advantageous, a two-way To arrange the protective layer between the substrate and the conductive layer. That second layer of protection came according to a further embodiment of the invention tlei have the same structure as the first protective layer. It is important to note that, as the first protective layer is permeable to aqueous oxidizing solutions, e it is not necessary that the second protective layer is permeable in a corresponding manner. As a result, the second protective layer can be thicker than the first Protective layer, for example up to about 1000 Å, but preferably has a layer thickness of voi less than 500Λ.

The second protective layer should be used if possible have an optical density of less than 0.5. The second Schulz is particularly advantageous layer, like the first, practically transparent, ti. Ii. sit has an optical density of less than 0.01. Is the double protective layer made of a metal halide built up which can be removed in the course of the plioiographic development process, st The optical density of this second layer does not affect the appearance of the final product.

The support of the photographic material of the invention can be made of any animal species known photographic support are dielectric, ti. H. tier a surface switch stood by at least 10 "ohms per square, in tie Usually about 10 '-' olim per square.

Typical dielectric substrates used for llerslel hung a photographic material after tie Invention can be used are hebeispielswei se layers of glass, paper. Wood, rubber lint daily Of particular importance are made of polymers! built-up substrate and the usual known

polymer-coated substrate.

Typical hydrophobic polymers, from which the support of the photographic materials according to the invention are built up, are, for example, cellulose esters, ζ. B. cellulose nitrate and cellulose acetate, Polyvi- ί nylaeeialpolymcre, polycarbonates. Polyester, / .. Ii linear polyesters of bifunctional saturated and unsaturated aliphatic and aromatic dicarboxylic acids and bifunctional organic polyhydroxy compounds, ζ. B. polyhydric alcohols, ζ. Β. κι polyester from alkylcnglycol and / or glycerol with terephthalic acid, isophthalic acid, adipic acid, maleic acid, fumaric acid and / or azelaic acid, also polyhalocarbonic acid, ζ. 15. Polyvinyl chloride, and finally polymeric hydrocarbons, ζ. B. Polystyrene π rol and polyolefins, especially polymers of olefins having 2 to 20 carbon atoms. The polymers described can be used in the form of flexible film supports or rigid supports or for coating glass, paper and polymeric film supports. Of particular importance are paper backings coated with-olefin polymer, e.g. B. paper backing that has been coated with polyethylene, polypropylene or Älhylen-ßulcn-Mischpolymensalcn. 2 ^r >

Is the surface of the .Layer carrier to be coated hydrophobic, i.e. to improve the adhesion of the water-sensitive hydrophilic colloid layer on a hydrophobic layer inclined surface, it can be useful to apply an in to apply the so-called air layer before the radiation-sensitive colloid membrane is applied. That’s the way it was for example in the KaIIc of Polycstcrschichtträgern, z. B. those made of polyethylene terephthalate, as advantageous It has been proven that an adhesive layer made of a Tcrpolymcrcn made of acrylonitrile or a Short-term acrylic acid alkyl groups with fewer than 4 carbon atoms in the alkyl group, a vinylidene halide and acrylic acid, e.g. B. to apply acrylonitrile or Mcthylaery-IaI, vinylidene chloride and acrylic acid.

The Sohichlcnsyslem used according to the invention An electrically conductive layer and a metal halide layer can be applied directly to such an adhesive layer be applied or directly to the hydrophobic polymer surface, since the metals which are used for the <r> Production of the conductive layer can be used, as well as the metal halides and metal oxides, which are used to Producing the second Schulzschicht can be used firmly on such Schichlträgeroberfläehcn be liable. "> <i

Indeed, it is surprising that the invention The anti-static layer system used adheres firmly to hydrophobic polymer surfaces.

The electrically conductive layers and metal halide layers can be applied to γ, clic layer supports by known methods. It has proven to be advantageous to apply the electrically conductive layers and protective layers to the layer support by vacuum coating. A Vakiiumdampfbcsehung isl a slightly diirehzuüh- ι, η mules process, which makes it possible to adhere to the .Schichtdicke of the layers to be applied exactly. A vacuum vapor coating also enables the protective layer to be applied directly to the electrically conductive layer without the electrically conductive layer being exposed to the action of the atmosphere. This avoids the formation of an oxide layer on the surface of the electrically conductive layer, as it is known that certain metals, in particular aluminum, form light oxide layers when exposed to the action of air. Such oxidic layers can, however, interfere with the oxidation of the electrically conductive layer in order to reduce its optical density. For example, aluminum antistatic layers which are used without a protective layer cannot be easily removed from dielectric substrates or made transparent, even if they are brought into contact with aqueous alkaline solutions having a pH above 11. In contrast to this, electrically conductive layers of aluminum, which were obtained by vacuum evaporation of a substrate and which have been coated with a selectively permeable protective layer according to the invention, without the aluminum layer being exposed to the action of air, can be made transparent easily and quickly under Use of customary aqueous alkaline working solutions with a pH of more than 9 but less than 11. This means that the ease with which the optical density of the electrically conductive layer can be reduced is promoted by the fact that the formation of surface oxides is prevented .

The radiation-sensitive layer can be made using one or more hydrophilic, water-permeable colloids are produced, which can be of natural or synthetic origin. Typical hydrophilic colloids for producing the radiation-sensitive colloid layer are, for example Proteins, e.g. B. gelatin and Gclatincderivate, cellulose derivatives, polysaccharides, z. B. dextran, gum arabic and the like, as well as synthetic polymers such as water-soluble polyvinyl compounds, z. B. polyvinyl pyrrolidone and acrylamide polymers.

To build up the radiation-sensitive colloid layer, it is also possible to use conventional, known hydrophilic colloids together with synthetic polymers which contribute to the dimensional stability of the radiation-sensitive colloid layer. Such synthetic polymers are described, for example, in US Pat. Nos. 3,142,568, 3,193,386, 3,062,674, 32 20 844, 32 87 289 and 34 11 911. Particularly effective polymers which increase the dimensional stability of the colloid layers have proven to be water-insoluble polymers made from alkyl acrylates and alkyl methacrylals, acrylic acid, sulfoalkyl acrylals or sulfoalkyl nicthacrylals, as well as polymers with cross-linked centers which facilitate curing or curing of the polymers, ■ / .. B. of the type known from US Pat. No. 3,488,708, and also those which have recurring Sulfobctaincinhcitcn, as z. B. from animal Canadian patent 7 74 054 are known.

The hydrophilic colloids can be prepared in a conventional manner by means of organic or inorganic llärlungsmiticl be hardened. For hardening For example, oil alone in combination with hardening mills made from aldehydes can be used can be used or so-called. Blocked aldehydes, as described in US Pat. No. 2 12 76Ί are, furthermore ketones, C'aiboxyläurilerivale and Carboxylic acid derivatives, sulfonates! Er. Sulfony halides and vinylsulfonyl ethers such as are known, for example, from US Pat. No. J5 J 4,644, and active ones

Halogen compounds, also epoxy compounds, aziridines, active olefins, isocyanates, carbodiimides, also polymeric curing agents, e.g. B. oxidized polysaccharides, z. B. dialdehyde starch and oxyguar gum and the like.

The radiation-sensitive hydrophilic colloid layer may be any of the usual known ones for Radiation-sensitive photographic recording materials used in the manufacture of radiation-sensitive photographic recording materials Connections included. The radiation-sensitive layer can be a Panchromatic or orthochromatic layer act or a layer that for example only opposite X-rays are sensitive to or only to selected parts of the electromagnetic spectrum.

Furthermore, a pholographic material according to the invention can only have a single radiation-sensitive material Have a colloid layer, d. H. a colloid layer in which a photosensitive compound is dispersed, optionally with customary known additives, such as those customarily used for the production of photographic products radiation-sensitive emulsion layers are used. On the other hand, the photographic material according to the invention have a plurality of colloid layers, it being understood that all or only a part of the layers can contain a radiation-sensitive compound. This means that, for example, the the hydrophilic colloid layer closest to the substrate or the adhesive layer applied to it does not necessarily have to contain a radiation-sensitive compound, but rather this one radiation-sensitive compound can be contained in one or more layers that are above such a hydrophilic colloid layer are arranged. So the photographic material after the Invention, for example, from a photographic recording material intended for color photography exist in which, as is known, a large number of radiation-sensitive colloid layers on one Layer supports are arranged, which are opposite to certain sections of the visible spectrum are sensitized. In addition to such layers, additional intermediate or top layers can also be present which do not contain any radiation-sensitive compounds. Typically the hydrophilic colloid layer which has been applied to the adhesive layer, e.g. B. on one of one Tcrpoylmeren built-up adhesive layer, itself does not contain any radiation-sensitive compounds. Typical hydrophilic colloid layers which can be applied to a hydrophobic layer support or an adhesive layer on this support and which does not contain any radiation-sensitive compounds contain, for example no silver halide, can for example consist of antihalation layers or layers containing nuclei, e.g. 15. image receiving layers, as used in standard chemical transfer processes, or dye stains and the same.

The radiation-sensitive compounds which are used for the preparation of the photographic materials according to Invention can be used can consist of a wide variety of compounds, the opposite are sensitive to electromagnetic radiation. Typical compounds sensitive to radiation are, for example Silver salts, especially silver halides, and zinc oxide.

The sirahluiiLTsensitive layers of a iiholographic Material according to the invention can, for example, also consist of layers of one radiation-sensitive polymers be built./. B. a photosensitive polycarbonate resin. this -> means that also polymeric radiation-sensitive compounds to build the radiation-sensitive Layers can be used.

Of particular importance are photographic materials according to the invention based on .Silberha-

κι logeniden, especially those with at least one silver halide emulsion layer. The silver halides are emulsion shells can use the silver halide in the form of silver chloride, silver bromide, silver bromide iodide, Silver chlorobromide, silver chloride iodide or

r> Silver chlorobromide iodide crystals or mixtures included. In the case of the emulsions used to produce the emulsion layers, it can are coarse-grained or fine-grained emulsions, which are made by customary known methods

> o can be produced. This means that it is the emulsions can be, for example, so-called single enema emulsions, such as those used, for example by Trivelli and Smith in the The Photographic Journal, Vol. LXXIX.

May 1939, pp. 330-338. described ", or so-called double enema emulsions, e.g. B. so-called Lippmann emulsions, also ammoniacal Emulsions or emulsions ripened in the presence of thiocyanates or thioethers, such as those for example in U.S. Patents 2,222,264, 3,320,069, and 3,271,157. Furthermore, for For the preparation of the photographic materials of the present invention, negative-type emulsions are used are like direct positive emulsions like them

r> for example in US Patents 2,184,013, 25 41 472, 35 01 307, 25 63 785, 24 56 953 and 28 61 885 and British Patent 7 23 019 and. the French patent 15 20 821 can be described.

■ in the production of the photographic materials According to the invention used silver halide emulsions can in a conventionally known manner with chemical sensitizers, for example with reducing compounds

• Γ) against existing sensitizers, sulfur, Selenium or tellurium compounds or gold, platinum or palladium compounds or combinations thereof.

The radiation-sensitive layers can des

^r , ii further contain the customary known additives as are customarily contained in radiation-sensitive layers of photographic recording materials. For example, the photographic emulsion layers can be so-called development modifying agents.

v, tel contain, furthermore antifoggants and stabilizers, finally plasticizers and lubricants, optical brighteners, spectral sensitizers and color formers, as they are for example in Sections IV, V, Xl. XIV, XV and XXII of the »Product Licensing

ho index «, IkI. ^l ) December 2, 1971, publication 9232, aiii pages 107-110.

As already stated, the photographic materials according to the invention can be seen with aqueous photographs EntwiekliingslÖK'ingen to be developed. at

ι, -; ilen crfiiulungsgcmill.lcn photographic materials However, it can also be a matter of avoiding aqueous developing solutions can be wrapped in a dry way. So it can

The photographic materials according to the invention also include, for example, photographic materials Silver halide based recording materials are used for recording Auskupicrbildem are determined, for example, in ilen US patents 23 69 449 and J4 47 927. Furthermore, you can do photographic photography in accordance with the invention Materials for making direct copy images be determined and have a structure, for example, from US Patents 30 3 ,! 682 and 32 87 137 is known. After all, they can Recording materials according to the invention can also be those which are produced by a so-called heat development process let develop e.g. 13. Those which have an oxidation-reduction image-forming combination with a photosensitive metal salt, / .. 13. a silver salt, as they are, for example, from ilen US Patents 19 76 302, 31 52 904 and 34 57 07 5 are known.

Optionally, the photographic Materials in addition, d. H. except for a metal halide layer and an electrically conductive one Layer, also have further customary known antistatic or conductive layers, e.g. B. Layers of or with soluble salts, e.g. 13. Chlorides or nitrates, or ionic polymers like them for example in US Patents 28 61 056 and 32 06 312 are described, or layers of or with insoluble inorganic salts, e.g. 13. of the type known from US Pat. No. 3,428,451.

After exposure, photographic materials according to the invention can typically be used in Brought into contact with alkaline and / or acidic aqueous solutions, for example developing baths, which are used for the purpose of silver reduction of silver halide emulsion layers and typically a pI value of over 9, or with fixing baths, which are used for the purpose of dissolving silver halides from the colloid layers can be used and typically a pH of less than 6.0, preferably less than 5.0.

An essential feature of this invention is that the pholographic working or developing solutions use for this! can be made to the electrically conductive layer by oxidation in an optically transfer less dense layer.

While it was previously known that certain metallic antistatic layers in the course of the are oxidized in the photographic development process, it is surprising to find that the conductive layers used according to the invention in these pholographic working or developing solutions can be oxidized, although they are protected from oil oxidation by the protective layer.

The manner and tier degree to which the optical density of the electrically conductive layer is reduced, can be different, depending on what kind of aqueous oxidizing solution is used, as well as depending on how the electrically conductive Layer and the protective layer are built up and depending on what thickness these layers have.

In most of the grooves, both the electrically conductive layer and the protective layers completely removed from the support, so that the developed photograph is a drawing painting Has no Diehleanliege due to the antistatic Schichlen system. While in some cases the protective layer itself is dissolved by the aqueous oxidizing solution used, e.g. 13. can be a Metal halide protective layer by a complexing agent, e.g. 13. a phosphate, which in the development or Working solution is contained, but it can be assumed that in most cases the applied one aqueous oxidizing solution first penetrates the protective layer and the electrically conductive layer oxidized. In the course of the oxidation of the layer capable of splitting, its adhesion to the layer substrate becomes smaller reduced, so that both the protective layer and the splittable layer separated from the substrate will.

Since the protective layers typically have a low optical density for metal halides, however, the protective layers can also be left on the substrate. In such grooves The electrically conductive layer can also be, at least in part, on the material in an oxidized, optically less dense condition remain. The layer system remains after the pholographic view has been carried out Development process on the substrate, it should preferably have an optical density of less than 0.5. In most cases the Schiehl system is completely removed or practical made transparent, d. H. it has an optical density of less than 0.01.

Another surprising feature of the invention is that certain metals, e.g. 13. Aluminum that normally not oxidizable when in direct contact with photographic work or Developing solutions come, easily converted into an optically less dense state by oxidation when used in conjunction with a protective layer that prevents oxidation of metals, for example aluminum, in the air.

The photographic materials according to the invention thus have the advantage. that they are a during have the keeping or storage stable anlislatic Schiehlen system and that the optical Density of this layer system in the course of the development process of the photographic material can be reduced without the need for additional process steps.

The drawing serves to explain the invention in more detail. In the F i g. 1 to 3 are photographs Materials according to the invention shown schematically in section before carrying out the development process.

In detail are shown in

Fig. 1 shows a photographic recording material 1, consisting of a dielectric layer carrier 3, preferably one consisting of a polymer Film layer carrier, on which are applied: a Schiehl system 5 from an electrically conductive Layer 7, which is applied directly to the substrate, and a protective layer 9 on animal electrical leilable layer and an adhesive layer II on the alitieren ropes of the layer carrier as well as a light-sensitive Emulsion layer 13 over the adhesive layer II;

l ^; i g. 2 a pholographic recording material 15. the structure of which in I'ig. I corresponds to the recording material shown, with the exception, however, that an I lal'lscliichl 17 / is arranged between the electrically conductive layer 7 and the layer carrier 5;

Fig. 3 shows a photographic material 19, which differs from the Aufzeichiiungsmaierialieii 1 and 15 of FIG. 1 and 2 differs in that the Adhesive layer 11 / wipe the emulsion layer Π and the layer support 3 is lortgela.ssen and that Antistatic layer system 21 consists of an electrically conductive layer 23, a first protective layer 25 LiiiLi a / wide protective layer 27 between the electrically conductive layer and the substrate.

The following examples are intended to illustrate the invention in more detail.

Example I.

In order to illustrate the superior stability of an antistatic screen system used according to the invention compared to an unprotected metallic manganese layer, a roll of polyethylene terephthalate film layer was used, a conventional air layer made of a terpolymer of acrylonitrile or methyl acrylate. Vinylidene chloride and acrylic acid, mounted in a vacuum coater. At the same time, magnesium fluoride was placed in a melting pot of the layering device. The vacuum chamber of the separating device was then closed and pumped out until a negative pressure of 3.2 10 ^r 'Torr was reached. The magnesium fluoride was then heated by means of an electric jet to a point at which it was strongly sublimated. Slides protecting the support material from the action of the magncsium fluoride were now opened, whereupon the support material was drawn through the magnesium fluoride vapor at such a speed that magnesium fluoride could condense on the support to a thickness of 50 Å. After the inspection process had ended and the magnesium fluoride crucible had cooled down, the negative pressure was released.

The layer carrier roll, which has a magnesium fluoride layer, has now been rewound and inserted Powdered manganese was introduced into the crucible. The vacuum chamber then became empty again pumped, whereupon the crucible was heated with the manganese powder. The base material was then pulled through the chamber again so that a layer of manganese is formed on the magnesium fluoride layer could deposit. A 60 Å thick manganese layer was produced.

One half of the roll was coated again with a /.wide MagnesiumfluoriH-layer a thickness of 50 Å, which was applied to the manganese layer.

In a further experiment, a 60 Å thick layer of manganese was applied directly to a polyethylene terephthalate Filmscn i t support carriers on fgct.

All coated carrier materials had a surface resistance of less than 10 ⁴ ohms per square.

The manganese that was applied directly to the substrate was completely oxidized after the material was left under normal conditions overnight. The support material with a magnetic fluoride layer and a manganese layer applied to it. which had not been masked showed a small increase in surface resistance when the material was kept under normal conditions for two weeks. whereas the layer carrier material with the manganese layer and two Magucsiunifluoridschichlen showed no change in the surface resistance characteristics. If the treated substrates were exposed for 12 weeks to an intrinsic moisture content of 50 ¹¹ A) at a temperature of 50 ° C, the surface ideal of the sample coated with a Magncsiluoridschichi increased somewhat, but the surface surface resistance remained below K) ⁴ Ohms per square. In the case of the test specimen with a manganese and a magnesium fluoride chloride, the surface resistance increased to 10 ¹ - ¹ ohm pm square, i.e. left to such a high level that effective antistatic properties were no longer present.

In those cases in which the acrylic resin containing terpolymer was used to produce the adhesive, the initial surface resistance was less than K) ¹ ohm per square, whereas when using layers of terpolymer containing methacrylate residues, the initial surface resistance was K) ¹ to H) ⁴ ohms per square were measured. On the other hand, the two adhesive layers provided test specimens with comparable properties.

The described antistatic coating systems completely dissolved in less than a minute a customary aqueous alkaline developing solution with a pH of 9 to 10 and that below specified composition:

Water, about 50 "C 500 ml
p-methylaniinophenolsulfai 2.0 g

Sodium silicate, dehydrated 90.0 g
Hydroquinone 8.0 g

Sodium carbonate, monohydrate 52.5 g
Potassium bromide 5.0 g

With cold water
made up to 1 liter

In a further series of tests were not on the ropes provided with a metal layer of the modified support photographic Gclatine silver halide emulsion layers applied. It was found that the antistatic scliiclitsystcmc used in the invention during the development process the exposed recordings have been removed, without the development process being disturbed or the quality of the pholographisclien obtained Materials was adversely affected.

Example 2

This example illustrates the preparation of a photographic material using a electrically conductive bismuth layer.

Following the procedure described in Example 1, a conventional Cclloscacetal film support a magnesium fluoride-Wistiiut-magnesium fluoride layer system applied. The method described in Example 1 was modified in such a way that that the bismuth layer and the Magncsiuinfluoriddeckschicht sequentially in one coating process using two electron beams heated crucible was carried out. The thin film base material produced in this way had a 50 Å thick magnesium fluoride layer, a 70 Å thick bismuth layer and a 50 Å thick Cover layer made of magnesium fluoride.

The layer system proved to be insoluble in conventional aqueous alkaline developer solutions yet it turned into one in less than a minute

2% acetic acid interrupter bath with a pH value of less than 6 dissolved.

When fresh, the pholographic material had a resistance of 4.2 10 ³ ohms per square. After a IOwöchken storage at a 50% relative humidity and 50 ⁰ C, the surface resistance decreased to 5.0 χ 10 ⁵ ohms per square. Although this resulted in a certain change in the surface resistance of the layer system, the surface resistance measured last is still so low that excellent protection against static charges is achieved.

In a further series of tests, a radiation-sensitive Gelatin-silver halide emulsion layer applied to the side of the substrate opposite the antistatic coating. That After exposure, material could be developed without being disadvantageous from the antistatic layer system.

Example 3

This example illustrates the use of a layer system with a conductive aluminum layer.

According to the process described in Example 1, aluminum layers of various thicknesses were applied to a polyethylene terephthalate film carrier, after which magnesium fluoride layers were applied directly to the aluminum layers produced. The surface resistivities of the coated materials were then determined, after which samples were stored the coated material at a relative humidity of 50% and a temperature of 50 ⁰ C. After a storage period of 3 or 8 months, the surface resistances were measured again. The results obtained are summarized in Table I below.

Table I.

Thickness of the layers Fresh Surface resistance after 700 in Ä material in ohms / square 3 months 8 months 4,000 AI- MgFz- after 100 2,600 layers Layers I 800 120 37 31 25th 320 > 10 ¹² 34 62 65 58 40 83 40 2.0 105 66 38 25th 22nd 35 200

In the following table II are the complete Solution of the layer systems, the times required are given in minutes.

Table Il

Thickness of the layers in Ä

Al-Schichl

Required for the complete solution of the layer systems
Time in minutes

37
34
40
66
22nd
50
50

MgF ₂ - Fresh 3 month old layer material material 31 3.5 3.5 62 2.5 > 10.0 83 3.5 > 10.0 38 5.0 5.0 35 1.3 1.3 50 3.5 5.0 - 5.0 > 10.0

All layer systems, with the exception of the system with the thinnest aluminum layer, showed after 8 months it still has an excellent surface resistance. But also the layer system with the thinnest aluminum layer, it still had a satisfactory surface resistance after 3 months of storage on.

In further experiments, test specimens of the materials produced were placed in an aqueous alkaline medium Developer solution of the composition given in Example 1 with a pH of 9 to 10 and a temperature of 23 ° C, immediately after their preparation and after a Jmonth retention period. In this series of experiments a support with an unprotected aluminum sheet was included.

In all those cases where the protective layer has a Thickness of less than 50 Å, there was no noticeable increase in the solution of the layer system time required by the layer support recognizable. In those cases where the protective layer greater than 50 Å in thickness, there was a slight increase in the time taken for removal of the layer system was required. When comparing materials with aluminum layers

jo an equal thickness can be observed that the protective layer reduces the time required for the Removal of the aluminum sheet is required, both in the case of a fresh material as well in the case of material stored for 3 months.

J5 Although longer periods of time are required to create layer systems with magnesium fluoride Schulz layers a thickness of more than 50 Å can be seen from Table I that this Schichlensystcme exhibit satisfactory surface resistance values over long periods of time and easily are removable from fresh material. Although these layer systems are also not completely in removed less than 10 minutes after a 3 month storage period, their optical properties become However, densities decreased considerably within this period of time. Appropriate results "will then obtained when aluminum on a cellulose acetate film support is knocked down. Since aluminum does not react with film substrate materials, isl no protective sub-layer required between substrate and aluminum.

In a further series of tests, a gelatin-silver chlorobromide emulsion layer was applied to the side of the support opposite the antistatic coating. Such recording materials exhibited excellent protection against static discharges, since the surface resistance of such materials was less than ¹² ohms per square. The pholographic characteristics

M) were not impaired by the presence of the antistatic layer system and neither were the removal of the antistatic layer system.

_(r> B eis ρ ie I 4

This example illustrates the use of an antistatic layer system consisting of a conductive silver layer and a magnesium fluoride

Protective layer.

In a vacuum coating device in which the material to be evaporated onto the substrate material by means of an electron beam A set of rollers was installed around which an endless belt of polymeric film backing material was installed could be performed. The roles could be adjusted by a coupling system and a mechanical one Drive the drive system outside the vacuum chamber. The endless tape left behind one Move the opening in a mask that is between the underside of the tape and the container with the to evaporating material was arranged. The opening was covered by a slider.

In the case of this example, the endless belt consisted of a polyethylene terephthalate film base. In the melting pot of Beschichtungsvorricntung pure silver was added, and then the vacuum chamber was evacuated to a pressure of 3.0 χ 10 ^-5 Torr. The silver was by means of an electron beam up to the evaporation point! heated, after which the support was allowed to revolve around the rollers at such a speed that each point on the support passed the opening 20 times per minute. After the slide above the opening had been opened, the silver was deposited on the layer support in a layer thickness of 25 Å. The slide was then closed again, whereupon the chamber was brought back to atmospheric pressure after the crucible with the silver had cooled down.

Magnesium fluoride was then introduced into the crucible, whereupon a mask was applied to the opening in such a way that only one half of the substrate could be exposed. The chamber was evacuated again to a pressure of 3 χ 10- ⁶ Torr, after which half of the width of the substrate material was coated with a magnesium fluoride layer having a layer thickness of 50 Å.

Test specimens of the coated materials were then exposed to ^{50% relative humidity at 50 ° C. for 6 weeks.} The surface resistances determined in the case of fresh materials and stored materials are compiled in Table III below.

Table III Fresh Warehouse properties Shift type material After 6 weeks longer storage surfaces Surface resistance resistance in in ohms / square Ohms / square 28 > 10i2 Just silver 25th 60 Ae + MeF2

20th

Both sections of the coated polyethylene terephthalate film support were found to be insoluble in aqueous alkaline developer solutions. However, it was found that the optical density slightly vermin- both the unprotected silver film as well as the protected by a magnesium fluoride layer of silver by the action of a conventional bleach bath μ to be able, for example, an aqueous Natriumferricyanidbleichbades of known from US-Patent 30 46 129 type.

Silver halide deposited on the film material during treatment in the bleach bath was easily removed using a conventional sodium thiosulfite based fixer with a pH less than 6, for example a bath with the following composition:

IU

15th

Water, about 50 ° C 600 mi Sodium thiosulfate 240.0 g Sodium sulfite, dehydrated 15.0 g Acetic acid, 28% 48.0 ml Boric acid, crystalline 7.5 g Potassium alum 15.0 g With cold water filled up to 1.0 LiI

remove.

The silver halide was created by reacting sodium bromide in the bleaching bath with the silver in the conductive layer.

The antistatic layer system could be completely removed in the course of a photographic development process and did not interfere in any way optical density of the developed photographic material. The magnesium fluoride protective layer was a problem the solution of silver in the photographic working solutions in no way.

Example 5

Following the procedure described in Example 4 was on a polyethylene terephthalate support A 60 A thick silver layer was applied without an adhesive layer. In the heatable with an electron beam Cerium fluoride was placed in the crucible.

A 200 Å thick cerium fluoride layer was then evaporated onto half a side of the layer support.

In further experiments were on polyethylene trephthalate substrates 60 Å thick silver layers were deposited, whereupon they were 400 Å thick Calciunif! Uoridschichl, a 300 Å barium fluoride layer or a 400 Å thick aluminum aluminum fluoride layer (Cryolite layer) were coated.

In all cases the metal fluoride topcoat protected the silver layer from abrasion and from abrasion Degradation during storage.

All of the materials produced had a surface resistance of less than 10 ohms each Square on, d. H. a surface resistance that is more than sufficient to make the material excellent to impart antistatic properties.

The layer systems proved to be insoluble in a developer of the type specified in Example i, however, could be used in a bleach bath of the composition given in Example 4 in less than 10 seconds bleach. The silver bromide that formed in the bleach bath dissolved in less than 5 seconds the fixer of the specified composition.

In further experiments, electrically conductive copper layers and protective metal fluoride layers were deposited on polyethylene terephthalate carriers in the manner described. In all cases, surface resistivities of less than 10 ⁵ ohms per square were observed in the case of freshly coated material and material stored for long periods of time. Furthermore, the optical density of these layer systems could easily be reduced by means of aqueous oxidizing photographic working solutions.

In a further series of tests, the

Support ropes that have not been coated radiation-sensitive colloid layers were applied. In all cases it was found that the obtained photographic recording materials before static Charges were excellently protected.

The photographic properties of the Materials neither by the presence of the antistatic layers nor by the Removal of these layers during the development of the materials is adversely affected.

1 sheet of drawings

Claims (9)

Patent claims: 1. Photographic material with a hydrophobic dielectric substrate, a non-static, electrically conductive metal layer with a surface contradiction of less than 10 '-' ohms per square, which by oxidation into a a comparatively less conductive layer with a comparatively lower optical density can be transferred is at least one sensitive to radiation Layer and optionally adhesive, intermediate and / or top layers, characterized in that that at least the side of the electrically conductive layer facing away from the layer support with a protective layer made of magnesium, calcium, Barium, cerium or sodium aluminum fluoride is covered. 2. Photographic material according to claim I, characterized in that the metal fluoride layer is formed has a thickness of less than 500 Å, in particular less than 50 Å. 3. Photographic material according to claim 1, characterized in that it is between the electrically conductive layer and the support a second protective layer with an optical density of less than 0.5, preferably less than 0.01. 4. Photographic material according to claim 1, characterized in that it is a support comprises a polyalkylene terephthalate or cellulose acetate. 5. Pholographic material according to claim 1, characterized in that the electrically conductive Layer has a surface resistance of less than 10 "ohms / square, especially less than 10 "'ohms / square. 6. Photographic material according to claim I, characterized in that it is a metal layer of silver, aluminum, bismuth, manganese, copper or mixtures thereof. 7. Photographic material according to claim 1, characterized in that (3 it as radiation-sensitive Layer has a silver salt layer, in particular silver halide emulsion layer. 8. Photographic material according to claims 1 to 7, characterized in that it is electrical conductive metal layer an aluminum layer free of surface oxides and as a metal halide layer has a magnesium fluoride or sodium aluminum fluoride layer. 9. Photographic material according to claim I, characterized in that the electrically conductive ge metal layer has a thickness of less than 100E.