DE2157834C2 - Photosensitive recording material - Google Patents

Description

The invention relates to a photosensitive recording material with a dispersion of photosensitive Crystals consisting of light-sensitive metal halides !! or organic or inorganic Photoconductors that are reducible as a function of exposure to real radiation, and on which a spectrally sensitive dye, possibly with the addition of a supersensitizer, is adsorbed, as well as with an inorganic semiconductor content.

Various so-called sensitization methods are already known in order to detect improper recording material len, in particular light-sensitive silver halide recording materials, by a Increase in the radiation absorption capacity for electromagnetic radiation and an increase in the photographic one Sensitivity to give an overall increased recording sensitivity.

According to such a known process, known as chemical sensing, this is the case relevant photosensitive recording material, for example a photosensitive silver halide material treated with certain compounds such as various sulfur compounds, such as the In US-PS 15 74 944, 16 23 499 and 24 10 689 mentioned, also with salts of noble metals such as ruthenium, Rhodium, palladium, iridium and platinum, all of which belong to group III of the perlode system of elements and have an atomic weight of over 100, for example with potassium chloroplatinate, sodium chloropalladite and Ammonlumchlororhodlnat, in quantities of which it has not yet become a substantial one Squint inhibition comes, as stated in US-PS 24 88 060, still with gold salts, for example Kallumaurothlocyanat, Kallumchloroaurat and Goldtrlchlorid, as in US-PS 25 97 856 and 25 97 915 is described, and with reducing agents, such as stannous salts, for example Stannochlorld, as in In the US-PS 24 87 850 is set out. According to US-PS 20 35 056, which will be dealt with in more detail below, 1st alongside the more common sulfur and selenium compounds, including a selenium sol as the sole chemical Sensitizer considered. These chemical sensing methods provide in the frequency domain the natural or natural composition of the crystal increases the sensitivity of the treated photosensitive Silver halide for electromagnetic radiation.

A second type of sensing process is known as what is known as spectral sensing known. This is intended to be a light-sensitive material, in particular a light-sensitive material Silver halide material, preferably certain frequency-selective sensitivity properties for electromagnetic Radiation and / or its inherent or natural spectral sensitivity properties can be increased.

Generally speaking, these spectral sensing processes are based on the adsorption of one or more Dyes on one or more surface (s) of the photosensitive material, these dyes too belong to certain classes of dyes, preferably including the cyanine dyes. For spectral sensing For example, a light-sensitive silver halide particularly suitable cyanine dyes are in F. M. Hamer, The Cyar, OE Dyes and Related Compounds, New York, 1964 (Intersclence Publishers) elaborated Treated me.

The conventional methods known from the prior art for the spectral sensing of a light-sensitive material, in particular a light-sensitive silver halide, are based on the fact that a cyan dye in the form of polymeric aggregates on the larger surfaces of the light-sensitive crystal has the thickness of a random monomolecular layer or In still lower strength is adsorbed. The cyanine dyes which are preferably used for the purpose of spectral sensing generally include an amidine / luminal system in which the two nitrogen atoms are in a separate heterocyclic ring system and in which the conjugated chain connecting the nitrogen atoms is connected by a telephone. of each of the heterocyclic ring systems. It is generally assumed that the adsorption comes about partly in the course of a chemical adsorption process, which has not been investigated in more detail, between the negative crystal surface charges resulting, for example, from excess halogen components of the silver halide, and the positive charge of the cyano chromophore silver complexes with cores containing a Amldlnlumstlcksioffatom the heterocyclic ring system or the heterocyclic ring systems of a selected Cyanlnfarbstoffs for example, together with an annular permanent sulfur, oxygen or i.-lenatom or with a di- f> ^ th ring permanent nitrogen atom that is not a direct component of of the Amldlnlumlonsystem ist.

In this context it is also known that the effectiveness of the spectral sensing,

for example a silver halogen crystal stable, initially increased to the extent that the adsorption of the selected In In the form of polymeric aggregates, the sensitizing dye is present on the corresponding surfaces or The area of the crystal increases until a concentration is reached at which the sensitivity becomes one Peak reached or flattened. In particular, it is known that the maximum sensitivity for a Concentration level of the dye is reached that of a dye coverage of the adsorbing crystal surfaces Corresponds to a strength that is less than or equal to that of a statistically monomolecular layer this, but mostly less than it corresponds to a monomolecular coverage of the crystal surface,

The sensitivity that can be obtained by a sensitizing dye does not increase proportionally Dye concentration, but rather a maximum is passed when the concentration increase.

One looks for the spectral sensitivity of the crystal by increasing the concentration of the corresponding Surface of adsorbed sensing dye above that of the flattening or the maximum of the To increase the corresponding degree of concentration in the course of the further increase in concentration leads to a progressive decrease in spectral sensitivity; see F. M. Hamer, The Cyanine Dyes and Related Compounds (as above) and A. V. Borin, Investigation of the

^IS Concentration Effect In Optical Sensltlatlon of Photographic Emulsions, Uspekhl Nauch. Fab. Akad. Nauk. SSSR, Otdel. ChIm. Nauk. 7, 1960, 183 to 190. In many cases the decrease in the spectral

The sensitivity of the crystal is downright drastic if, for example, one considers the effect of a

gradually increasing the sensitivity by a certain amount before reaching the flattening or maximum value required relative proportion of the dye with the effect of the same

Comparing the proportion of the amount after the point of the optimal Senslllslerung is exceeded.

The ability of a photosensitive containing a particle of a photosensitive material Element for energy or charge carrier absorption generally depends on the effective one Adsorption caused the presence of a sufficient amount of dye to cause maximum absorption and transmission of the photoreaction impulse triggered by electromagnetic energy to the llchtemp-

^{2 <} International material to effect. The adsorption of the dye in the thickness of the above-mentioned monomolecular layer on the corresponding surfaces of the photosensitive material is largely unable to ensure complete absorption of the incident radiation. In the case of the light-sensitive recording materials used for photographic purposes, which are normally spectrally sensitive, for example in the case of panchromatic photographic emulsions, which are in a relatively thin layer of, for example

J "about seven Mlkror, are applied to a suitable substrate and a dispersion of a photosensitive Sllberhalogenlds in a gelatin matrix in a concentration corresponding, for example about 100 mg of silver per 0.09 m containing ^J, the light-sensitive material is absorbed in the entire desired radiation frequency range large duly actually only less than about a third of the total incident light, which means that the potential or theoretical usefulness of such elements is not nearly exhausted Radiation amounts to about seven percent of the inägesarnl outward radiation, see above W.

West and V. I. Saundere. Scientific Photographic (Eds. W. Elchler, H. Fieser and O. Helwlch), Darmstadt 1958, p. 48 (Verlag Dr. O. Helwlch). The overall behavior of the system can therefore not be favorable as a result It is possible to influence the fact that one only increases the proportion of the sensitizing dye, but it can be done It is only in the catfish that more suitable and effective sensitizing dyes can be developed.

The photographic effect can be as that in the transmission of an electron or energy excitation a photosensitive material such as a photosensitive silver halide crystal, observable Result can be defined. The photographic effect can therefore be used for practical purposes Measurement can be made available in a specific photosensitive material through such an excitation stimulus induced photochemical change determined by which the individual grains become viable and thus image generation is made possible. The mentioned stimulus, who changes the peculiarity of the photosensitive material can either directly affect this the incident electromagnetic radiation or from a dye that is attached to the light-sensitive grain is adsorbed or added to this material. For such a photographlscrrn Process are on the one hand the number of absorbed excitation quanta and on the other hand the relative quantum yield of the absorbed quanta determining, with the quantum yield as MaQ for the proportion of in the sense the triggering of photochemical changes in the quanta that take effect, based on the total quantum absorption, is to look at.

In an effort to further increase sensitivity, taking into account the spectral sensitivity The problems outlined above that have arisen is also known as a so-called super sensitivity called technology became known. In this context it is known in detail a monomolecular layer of several synergistically interacting layers on a light-sensitive crystal surface To bring material components to the Aiisorptlon, at least with one of these Components around a cynanine dye and with all other substance components mostly, but not in In each case, several appropriately selected cyanine dyes of different types are involved in this way to achieve an increase in the quantum yield with photon excitation; but was after The current level of development of this technology merely suppressed the inevitable desensilism anxiety tendencies conventionally used as a sensing medium for spectral sensing th cyanine dyes possible.

From the already mentioned FR-PS 20 35 056 1st - In the context of the chemical treated above in general Sensibilisiening - provided as the (only) chemical sensitizer kcüoldales selenium, with as a further possible additives also include spectral sensitizing dyes, such as cyanines. From this publication

Therefore, in the context of a combined application of chemical and spectral detection, the Use of a selenium as the (only) chemical sensitizer in conjunction with conventional spectral sensitizers Dyes, in particular cyanine dyes, are known. The selenium sol is in the for chemical Sensitizers usual, very low concentration of the order of 0. (K) IJ b7w 0.0014 g selenium included per mole of Ag.

The US-PS 23 36 260 relates to a photographic recording material with at least / wet Nebeneliuiuk'r present silver halide emulsions, at least one of the emulsions containing a sensitizing dye Is senslblllslert. The problem of an undesirable migration or diffusion tendency arises here of the sensing dye from the grains of one emulsion to the grains of the other emulsion. As a diffusion inhibitor to block or reduce such undesirable migration of the In this publication, the setting dye is the inclusion of an essentially water-insoluble Metal compound from the group of metal oxides, metal hydroxides, metal oxide salts and metal hydroxy salts and metal salts of synthetic resins are provided, these metal compounds acting as a diffusion inhibitor is added to the emulsion after incorporation of the sensitizing dye. As one for this purpose as Diffusion inhibitor particularly effective metal compounding If zinc oxide is mentioned, this diffusion inhibitor additive generally In an amount of 10 to ISO g of water-insoluble metal compound per mole of silver halide should be present.

It is an object of the present invention to generally increase the sensitivity of light-sensitive Recording material ^ of the type mentioned above, d. H. an improvement in the photographic Efficiency of the implementation of the electromagnetic occurring in the form of light quanta or photons Radiation In photographic effect (blackening by reduced silver in the case of silver halide recording materials, or the corresponding increase in the sensitivity of parents with Phctol light-sensitive elements working as light-sensitive particles for the purpose of electrophotography), in addition, the known sensation processes are overcome by the above-mentioned saturation effect with subsequent desensitization even starting with a further increase in the sensitivity dyes set limits.

For this purpose, in the case of a recording material of the type mentioned at the outset, according to the invention provided that the inorganic semiconductor to / electron donation to the photosensitive crystals depending on associated with an exposure, its Leltfählgkeltsband energy level above that of the light-sensitive Crystals lies. In his band scheme a larger band corner ("forbidden band") than the spectral sensor has a higher color level than the spectrally sensitive colorant and / or has the photosensitive crystals, in the case of silver halide as the photosensitive crystals The molar ratio of silver halide to semiconductor is from 1: 1 to 100: 1.

According to the basic idea of the invention, in surprising and unexpected catfish can be another fundamental increase in sensitivity over that which has already been optimized according to the prior art Systems achieve achievable value. By using the two-component system of photosensitive Crystals and the spectral sensing or super-sensing system adsorbed thereon into one Drel component system with an inorganic Haibieüermaieriai efweiicfi, soft certain conditions for the relative position of his band scheme and Ferml level with respect to the used sensing system and / or the photosensitive crystal is sufficient; namely the inorganic 41) see semiconductors in terms of the relative position of their banding scheme and Fermllevel in terms of the photosensitive ones Crystals and the sensitizing dye depending on the actual exposure of the Drel component overall system able to deliver electrons. Without the following explanations is to have a restrictive meaning, it can be assumed that the surprising increase in sensitivity in the system according to the invention by a special one Electron transport mechanism is achieved, according to which electrons from the current through the impinging Radiation optically excited Sensiblllslerungsmaterlal and / or semiconductor material in the conduction band of the Pass over halogen crystal stalls, either on the way from the semiconductor via the sensitive material and from this as a cascade to the halogen crystals, and / or with an optical excitation of the sensing material directly to the silver halide crystals and / or upon optical excitation of the crystal and / or the semiconductor Within the respective spectral range of your light sensitivity also from the semiconductor directly to the silver halide crystals. In terms of semiconductor physics can use the Drel component system according to the invention (made of light-sensitive crystal, sensitizing dye and inorganic semiconductor according to the invention) the conventional two-component system (from light-sensitive crystal and sensitizing dye) are contrasted in similar catfish, like a Transistor (with gain) of a diode; according to this functional analogy, the sensitizing dye could be with the base of a transistor, the photosensitive silver halide with the collector and the invention selected inorganic semiconductors with the emitter, d. H. compared to the electron donor turn around.

Overall, the invention is based on the fundamental knowledge that the need for electrons in the bellteten Grain regions is a limiting factor for the yield of the photographic process, and that by providing additional electron supply Depending on the Gesamtbeiichtung of the System can achieve an increase in sensitivity, this providing additional electrons in Dependence on the total exposure is made possible by selected inorganic semiconductors.

Such a Drel component system according to the invention in the sense of an electron transport mechanism for increased electron supply to the grain. From the publications already mentioned above, the FR-PS 20 35 056 and US-PS 23 36 260, in which, each an inorganic semiconductor material (Selensol or ZnO) is present in connection with a sensitizing dye, not known. This is used in the FR-PS

η y /

Selensol as a chemical sensitizer; it is extremely common for such chemical sensitizers application of low concentrations that are of the order of magnitude smaller than the content of the invention selected inorganic semiconductors are in the system according to the invention. Otherwise it would be selenium according to his band scheme and Ferml level not those for the electron transport mechanism according to the invention Have required properties in the context of the photosensitive material. The same applies to the use of ZnO known from US Pat. No. 2,336,260 in association with a sensitive multi-emulsion system. The ZnO serves as a diffusion inhibitor against undesired diffusion of the sensitizing dye. from one emulsion to another; it finds application for this purpose in a multitude that above that provided for the inorganic semiconductors according to the invention in the system according to the invention ίο is the concentration range, and according to his ribbon scheme and Fermlnlveau it would not be the semiconductor-physical one Satisfy conditions for the inorganic semiconductor in the system according to the invention.

A material is particularly preferably suitable as the inorganic semiconductor material for the purposes of the invention from the group PbO (orthorhomblsch). Ge, AlSb, ZnSe, AIAs, GaAs, InAs, InP, GaP, GaSb, Sn, Sl, Ge, SnS.

ii According to a preferred embodiment it is provided that the spectrally sensitive dye has a Leitfählgkeltsband energy level above that of the photosensitive crystals. For use in Particularly suitable spectrally sensitive dyes for the system according to the invention are cyanine dyes according to claim 4.

-;: The invention also relates to a method for producing such a recording medium, wherein

a mixture of the dispersion of the light-sensitive crystals and the spectrally sensitive crystal is first used Produces dye and then adds the inorganic semiconductor to this mixture, or alternatively first produces a mixture of the spectrally sensitive dye and the inorganic semiconductor and then adding this mixture to the photosensitive crystal dispersion.

Details of the invention and exemplary embodiments are explained below with reference to the drawing; In this shows

'Flg. 1 is a graphic representation of the activity spectra determined with a Kell spectrograph of a with

a sensing dye-spectrally-sensitized silver iodine / chlorine bromide demulslon known from the prior art.

'Flg. 2 shows a graphic representation of the photoreaction spectra determined with a Kell spectrograph

a silver-iodide-chloro-bromide-demulslon which is sensitized with a sensitizing dye and which is produced according to ^:. Invention a Partchendlsperlon of a semiconductor was added; and

': · ■.: ■ Flg. 3 shows a graphic representation of the photoreaction spectra determined with a Kell spectrograph

, _: ,; an iodochlorobromobromide emulsion, which according to the invention is a premixed combination of a Senslllsle-

^ S rung dye and a Partchendlsperslon of a semiconductor was added.

|! According to the invention, an intensification of the photographic effect of a photosensitive

il material by increasing the electron transport to the light-sensitive material from a Belgian

Next electron source in the form of a sensitive dye and an inorganic! Semiconductor achieved

'■' -. which provide a flow of electrons in response to incident electromagnetic radiation

;, -: able.

\ ^J _: 40 In general, the absorption of the activation energy resulting from photon excitation, belsplels-

% thus wise the energy of a photon, through a light-sensitive crystalline material in the structure of the

^? ; Crystal to transfer an electron from a state of lower energy to a state of higher energy.

; same. The photosensitive material is thereby brought into an electron excited state, resulting in

The consequence is that free electrons and imperfections are generated where the electrons are located before they strike.

ij '45 fen of the activating radiation and which act like positively charged particles, namely as positive

Ji "holes".

Silver halides are themselves semiconductors and contact with an activating photon drives you to

] -; Raising an electron from the valence band into the conduction band, where it is then in the excited state

fij frclmobilllch ist, can be recaptured and assigned to an available adsorbable silver ion,

so that a latent image is formed which can be converted into a visible photographic signal.

The latent image thus formed in the light-sensitive material containing the silver halide is, can be developed or reduced according to one of the known, customary catfish processes, whereby one when in contact with reagents that come into contact with an exposed light-sensitive material, i.e. a latent image imprinted Reacts differently than with an unexposed material than the visible result differences material type.

This phenomenon of the excitation of a light-sensitive material is detailed in the extensive phototechnical literature, see for example Mees, Theory of Photographic Process, 3rd ed., 1967, Chapter 1 (MacMillan Company).

As is also known in the art, the response range of the photosensitive Materials, d. H. the wavelength range in which a certain light-sensitive material is sensitive, extends or the photographic behavior of the light-sensitive material within the »! Absorption range can be intensified by using a spectrally sensitive dye or adding several such materials. The effects of such spectrally sensitive dyes are based that they are exposed to the light-sensitive material under the influence of incident radiation of wavelengths for the sensitive material and / or d & t light-sensitive materia! Is sensitive to electrons deliver. Thus, according to the known prior art, an expansion of the catfish described above was possible the photographic effect of light-sensitive materials in the range of high wavelengths due to the Verwencking a spectrally sensitive dye can be achieved, namely a material that

characterized in that it is in response to activation energy supplied to the system at a light-sensitive material is able to donate electrons.

An unexpected increase in the photographic performance of a light-sensitive material can be achieved However, if one uses a sensitizing dye for this which at the same time is also an encrglcuherirn · gender substance is, and an inorganic semiconductor is used, which under the influence of a stepping elec- > Electromagnetic radiation is able to emit electrons to the light-sensitive material. The one so produced Reinforcement effect Is not merely of an additive nature, nor is it a mere one Higher development of the active properties of the sensitizing dye ^, but it results in such Scope In advantageous and unexpected properties, as is the case with the prior art conventional systems and methods are not within the realms of possibility.

The invention can be applied to a variety of photosensitive materials. As photosensitive Materlallen are mostly used the light-sensitive metal halides, for example the Silver halides, namely Sllberchlorld, Sllberbromld, Sllberjodld and mixed halides such as Sllberjodldbromld and Sllberjodldchlorldbromld. Other metal halides include the halides des Lead and thallium in consideration. As is set out below, within the scope of the invention can also inorganic photoconductive substances such as zinc oxide and titanium dioxide, and organic photoconductive substances such as for example anthracene and polyvinyl carbazole, are used as light-sensitive components.

The term "light-sensitive" is intended to denote the property of a Materials serve, the activation energy in the form of an occurring radiation of certain wavelengths can be supplied and that, caused by the occurrence of this radiation, in tier Webe inuiiifikieibai isi,; o that a photographic signal is obtained as is not obtainable from unexposed material either or at least not available in an effectively different intensity.

The sensing dyes used in the context of the invention provide the extension mentioned above the photosensitivity of the selected photosensitive material, d. H. they deliver to the photosensitive Material Depending on the light-sensitive material and / or the sensitizing dye supplied activation energy additional electrons. The sensitizing dye can also have the ability possess to act as a bridge for the transmission of energy, namely as a conductor material, so not only the to supply electrons released by himself to the photosensitive material, but also to also to receive and forward electrons from the inorganic semiconductor, whereby the active catfish If the radiation hits the light-sensitive material, it can affect Jo uen semiconductors and / or the sensitizing dye to donate electrons.

The sensing dyes used in the context of the invention are conventional, Material known from the prior art, which In said article entitled The Cyanine Dyes and Related Compounds (as above) are precisely described and listed in detail and which are also In a large number of foreign patents are mentioned, which include spectral sensing Use of sensing dyes for spectral sensing for photographic purposes Have subject.

The inorganic semiconductor to be used is capable of the other components of the Drelderr.entesystem to deliver electrons under the influence of the activation energy supplied to the system. So you go assume that, within the scope of the invention, directly or indirectly, a photographic recording by the If the light-sensitive material component of the system comes, then the electrons in the light-sensitive Material can be made available as free electrons to build up a latent image. The sensitizing dye conveys an increased and / or spectral sensing of the light-sensitive material, In that, triggered by the exposure and in dependence on this, an influx of electrons to the photosensitive Brings material to bear. Because this In the sensitizing dye and / or In the photosensitive If an electron deficiency occurs, it also occurs in the inorganic semiconductor material for electron donation. Although it is, of course, clear that due to the lack of electrons in the sensitizing dye, namely due to the presence of positive "holes" as a result of electron transport to the photosensitive material, electrons are attracted, and although as a result of this caused Accumulation of electrons in the sensitizing dye because of the limited electron capture cross-section of this dye, which is attached to the light-sensitive material, still more electrons in the Flow to the photosensitive material, the flow of electrons may in certain Cases wholly or partly also directly from the inorganic semiconductor material to the photosensitive Material.

; In the above description of the operations in the photographic system of the present invention, such as assumed that the activation energy is supplied to the photosensitive material. However, it is too note that a similar electron transport also occurs when the activation energy is only is added to the sensitizing dye, d. i.e., if the activation energy is assigned a wavelength which is absorbed only by the sensitizing dye alone or that by the light-sensitive material and can be absorbed by the sensitizing dye. ω

It has been found that the various routes which can be taken to produce the photosensitive elements are not of decisive importance in the context of the invention. The presence or absence of binders for the photosensitive material is also not decisive and the invention extends both to such photosensitive materials in which binders are provided, which here can refer, for example, to the photosensitive silver halide embedded in gelatin, as well as to materials that are completely binder-free, for example materials that are vapor-deposited in a vacuum.
The invention thus creates a light-sensitive system in which, even without applying a

External field a photocurrent amplification can take place, which leads to the build-up of a latent image. fs

With the usual spectral sensing, for example of silver halides by adsorbed organic B! Dyes, it turns out that the photographic quantum yield in the range of the spectral sensing Im **

is generally lower than the quantum yield in the eigen area In the absence of the sensitiser!. '

and that the color sensitivity can accordingly be traced back to electronic pn junction effects vf,

can. These systems or devices are or act as solid state diodes. H

Such solid-state diodes do not represent amplifiers, however, and an amplification effect has never been observed so far

been respected. By adding the third junction to such a diode, a device §3

of this kind, however, can be converted into a transistor or into a transistor-like system, so that now »:

ίο a potential gain is also possible. The systems according to the invention, in which as a material for the Fe

second transition an inorganic semiconductor is used, so can directly with a transl? i

sturgeon can be brought into analogy. In fact, even without the action of an external electronic field, | j

an enhancement of the photographic effect by more than eight times has been achieved. ■ (:

In particular, three-element systems of the type described were tested in which Sllberchloridbrornld- g Gelaline emulsions as well as binder-free systems in connection with blue-, green- or red-colored emulsions

the dyes and an inorganic semiconductor such as orthorhomeal PbC. In such a system, the function of the dye is to be regarded as the base of the transistor, the \\

Silver halide as the collector and the PbO as the emitter or electron donor. §] It is clear that the addition of a p-type sensitizing fiber to a light-sensitive type n-type ^:

*> the crystalline material at the interface because of the equalization of the Ferml levels in the two phases

Formation of a space charge leads. If the Fermin level of the crystalline material is above that of the dye -;

is, the crystalline material is positively charged, while the sensitizing dye is negatively charged. The other Addition of the n-halelier then requires a second readjustment of the Ferml level and one obtains one npn transition. It should be noted, however, that certain semiconductor materials, without prejudice to the fact that there are If you, like orthorhomblian PbO, are p-half-parents, you will have a higher Ferml level than the dye, thus resulting in a three component system which, as the functional equivalent of one npn transition can be considered.

An exposure In that Spectral Geblet. In which only the sensitizing dye absorbs light, so '

outside the inherent sensitivity range of the selected photosensitive crystalline material, would be in Absence of the third component of the system In known catfish a migration of electrons In the trigger photosensitive crystals that make up the photosensitive material. The electron donating semiconductor however, is indicative of an increase in the number of holes In dem caused by this migration Sensitizing dye and / or In the photosensitive crystal upon photoexcitation Within the intrinsic range on and reacts with the release of electrons, whereby the influx of electrons to the KrIsUlI

.is is increased as a result of the additive effect of the secondary electrons emitted by the half-parent phase.

In the above-described systems according to the invention it has been shown in many cases that the photographic Yield In the spectral range in which only the dye absorbs light. Compared to that Two-component or diode system is approximately eight times and that the spectral absorption range of the systems is generally not changed by the presence of the semiconductor. An estimate of the

■ to photographic yield in the dye absorption area in the presence of a semiconductor Compared with The intrinsic range in the absence of a sensilizing agent also indicates that the yields approximately equivalent and in certain cases may be higher with respect to the dye absorption range. The reinforcement effect also appears to occur independently of the presence of an inorganic semiconductor, the wavelength absorption edge of which is longer than the absorption edge of the particular chosen sensor-clearing dye.

With regard to the electron transport mechanism, it is specifically assumed that the sensitivity of the photographic process is increased by the fact that electrons from the impinging Actual radiation optically excited Senslllslerungsmaterlal and / or semiconductor material in the conduction band the silver halogen crystals go over, be it now on the way of the semiconductor over the sensor material and from this as a cascade to the halogen crystals and / or with an optical excitation the senslllslerungsmalerlals directly to the silver halide crystals and / or with an optical stimulation of the crystals and / or the semiconductor Within the respective spectral range of your light sensitivity also from semiconductors to silver halide crystals. More specifically, a silver halide crystal that can be regarded as an n-half-parent who has a higher band gap energy than a selected equilibrating dye, with the sensitizing dye identified as a p-half-parent with a low Ferml level, a lower band gap energy level and a higher conduction band level than the silver halide crystal can be considered, and brought into contact with a chosen semiconductor, which is also a higher Ferml level, has a larger band gap energy level and a higher conduction band level than the silver halide crystal and preferably also a higher Ferml level, a larger band gap energy level and

If it has a lower level of conduction band than the sensitizing dye, it appears to come before exposure immediately to certain changes. In particular, there appears to be a flow of electrons from the "n-half-ele terx halide to the" p-half ele-sensitizing dye and also from the conventional n-half-parents to the dye, resulting in an approximation of the Fermllevel of the concerned Materlallen leads. In accordance with the notions of the well-known half-elector theorle (see belsplelsweise A. Nussbaum, Semiconductor Device Physics, Prentice Hall. New Jersey 1962, p. 93 and R. H. Bube, Photoconductivity of Solids, John Wiley and Sons, New York 1960, p. 78) would therefore increase as a result of the Concentration of electrons in the sensitizing dye and a correspondingly increased concentration of the defect electrons In the Sliberbromld form a space charge in the area of the interface, which

Upper stretches On the order of a micron, stretched into the relevant mass phases. (For particle materials with small particles, such as silver halide crystals, this space charge can penetrate extend through a substantial portion of the system). The polarity is such that the silver halide Is finally positively charged, the sensitizing dye is negative, and so is the n-half parent positive. s

When exposed, for example when light is absorbed by the sensitizing dye beyond the In the area of the Elgen absorption tone of the silver halide, electrons are moved from the valence band into the conduction band of the sensing dye and / or the semiconductor is raised. Because of the even before the exposure process The built-up space charge can now electrons through the interface from the sensitizing dye and / or the semiconductor flow to the silver halide, where they are used to build up a latent image become available. From a practical point of view, this means the formation of new curve peaks In the spectrum of activity of the sensitive silver halide compared to that of the non-sensitive Materials.

Silver halide demulsions, such as those used in the manufacture of photographic recording materials preferred are those which have a content of sensitized, light-sensitive silver halide crystals, As detailed above, can be prepared in such a way that one water-soluble silver salt, such as silver nitrate, with at least one water-soluble halide, for example ammonium, potassium or sodium bromide, preferably together with a corresponding one Iodine, in an aqueous solution of a peptide dissolving agent such as a colloidal gelatin solution, converts, then digests the dispersion at elevated temperature in order to promote crystal growth, whereupon the so-called dispersion obtained to remove the undesired reaction products and the remaining products Washed out water-soluble salts while cooling the dispersion, the solidified dispersion noodles and the noodles are washed out with cold water or, if desired, one of the different ones Flocculation possibilities or procedures are used to eliminate undesirable Ingredients are suitable, such as any of U.S. Patents 2,614,928, 2,614,929 and 2,728,662 described method catfish, then to the dispersion at elevated temperature in connection with the Addition of gelatin and / or other, optionally desired polymeric materials as well as various To allow additives, for example the above-mentioned chemical sensitizing agents and the like, to age. These measures are all carried out in accordance with conventional technical catfish as they are at C.B. Neblette, Photography, Its Materials and Processes. 6th edition. 1962, » are described.

A gelatin-silver iodobromide demuslon prepared in the above catfish with a gelatin-silver ratio of about 1: 1 and with a bromine content of about 4 mol% can be used, for example, with gold and Sulfur can be chemically sensitized that at about 56 ° C at pH S and pAg 9 an optimal sensitizing effect Amount of a solution containing 0.1 g of ammonium thlocyanate in 9.9 ml of water, a solution With a content of 0.097 g of gold chloride in 9.9 ml of water and a 0.02% aqueous sodium sulfate solution adds.

The spectral detection of the silver halide crystals of the dispersion can then be carried out in the catfish be that the emulsion mass with an effective amount of the chosen, for spectral Senslllslerung suitable cyanine dyes or more such dyes brings together, these dyes preferably all in a suitable dispersant such as methanol, ethanol, pyridine, acetone or water, and the like. Are dissolved, which is also with the conventional technical process catfish In Is consistent, as they are described, for example, in the aforementioned foreign patents. in the In general, the concentration of the sensing dye or dye that is present may be with the preferred silver iodobromide dispersions usually in the range from 0.05 to 5 grams each 100 grams of silver halide, calculated as silver, will hold, depending on the properties of the photosensitive in question Material, for example the selected silver halide, and depending on the desired sensing effects can be varied empirically.

In particular, however, the approach can be spectrally sensitive within the scope of the invention that one while maintaining a sufficient concentration of the one or more aerosolized here led to the addition of, for example, 1, 2 and, cyanine dyes suitable for spectral sensing 4 mg of the cyanine dye of the formula 1 below, dissolved in methanol, for every 1 gram of silver undertakes.

If desired, the emulsion can be applied as a layer to a suitable substrate, whereupon this layer is then immersed in the relevant solutions of the selected cyanine dyes.

The introduction of the semiconductor selected as an additive in the approach can be carried out before the spectral sensing, at the same time as this or after it.

In detail, the semiconductor in the catfish can be introduced into the approach that it is in the form of small pieces Suspended in a liquid medium in which it is insoluble and that for photographic emulsions is harmless, such as water, methanol or another alcohol with a low molecular weight, or in a mixture of water and alcohol, whereupon the suspension formed in this way then becomes the above Approach described is added and mixed with this thoroughly.

If desired, the silver halide can also precipitate in such a catfish in the presence of the semiconductor that a structure with core and shell is created, with any one of the two substances, thus either the silver halide crystal or the blelox plate, the core or the shell can form.

With regard to the proportions of the semiconductor and the silver halide, it could be determined that that good results can be obtained in a wide range of different ratios. In particular Silver halides could be sensitized according to the idea of the invention in effective catfish.

by maintaining molar ratios of 1: 1 to 100: 1 for the silver halide and the semiconductor, although higher or lower ratios can also be suitable, which in each case depends on the desired emulsion and sensitization properties.
The particle size of the semiconductor material is not of decisive importance, although it is clear to a person skilled in the art who are familiar with semiconductor theory that the particle size and structure must be such that sufficient interface contact is ensured between the silver halide crystals and the particles of the sensing dye and the semiconductor 1st. In practice it has been shown that sonicated suspensions of the semiconductor give particularly good results, since the submicroscopic particles can then partially coat the silver halide crystal. From the above discussion of the tivoretl-

! 0 see basics, however, it follows that the sensitization activity of the semiconductor does not depend on the training depends on a real demilitarist; rather, the electron transport can take place without further ado, provided that there is at least a certain minimum of effective electronic communication between the individual reaction partners Contact exists. As for silver halide isolation and reinforcement, there are no theoretical maximum for the particle size of the semiconductor.

However, the particles should be of a sufficiently small size and concentration to make the photographic Properties of the silver halide emulsion not to be adversely affected, for example by Reflection and / or scattering of the incident radiation to an appreciable extent. So 1st it is for example for common silver halide emulsions with a thickness of 0.6 to 20 microns, their Silver halide grains in an average particle size distribution in the range from 0.1 to 10 Microns are preferred when the particle size distribution of the halved particles present is In the range holds 0.1 to 10 microns. The smaller the size of the semiconductor particles, the smaller it is of course, those used to enhance the sensitivity of a given amount of a photosensitive crystalline Silver halide amount of semiconductor required, expressed in absolute weight. It cherishes It is obvious that the specification of absolute values with regard to certain particle sizes of the semiconductor and its weight ratio to a silver halide only for a single one that can be precisely identified Sllberhalogenldsystem can be useful, and that with knowledge of the invention without further ado within the scope of usual technical ability to determine empirically the specific parameters, which one must make use of the practical application of the invention in order to achieve optimum results in the sensing process to achieve.

It should be noted that the semiconductor particles suitable for use in the invention can be produced by any conventional process, such as those used for the production of Solid particle materials come into consideration, for example by processing in a ball mill, by sand grinding or by ultrasonic machining. In general, a moist paste consisting of the solid half-loafers and optionally from one or more other substances, namely pearl pearls, Surface-active agents, EnI .haumern and antioxidants, as well as from water according to one of the above Process catfish are processed so as to produce particles of the desired size, whereupon the after The mass obtained in each case selected workup method, if desired, filtered in a suitable catfish can be to remove any remaining particles whose diameter is larger than the corresponds to the intended particle size range.

The conventional sand cleaning methods suitable for achieving the required particle size distribution consist in general of stirring an aqueous half-parent slurry with a sand, whose particles live, for example, in a size range corresponding to the US standards with 20 and with 40 meshes per inch (clear mesh size 0.4 to 0.85 mm), until the desired small size distribution reached 1st, whereupon the semiconductor is separated from the grinding sand. To carry out the

Commercially available grinders of different capacities are available for the sand grinding process.

In order to produce a semiconductor material with the desired particle size distribution by ultrasound methods, an aqueous half-parent slurry can be treated with a commercially available sonication device.
After the solution has been completed, further desired additives can be added to the emulsion,

For example, coating auxiliaries, on which the mixture is applied as a layer and according to the known Methods for the production of photographic recording material ^ can be further processed.

The sensitive approach can then be placed on a suitable base, such as a cellulose tetrlacetate carrier can be piled up and the thus prepared drawing materials can be used in a standard Cell spectrographs can be exposed to determine the specific wavelength target of the approach for incident c to determine electromagnetic radiation.

After treatment with a photographic developing agent, for example a commercially available one Substance In the form of an aqueous alkaline solution of monomethyl-p-aminophenol sulfate and hydroquinone, and with a conventional acidic interruption bath, the spectrograms obtained show the sensitivity properties of the spectrally sensed approach, which are then directly linked to those of a

M> trally sensitive sample can be compared or with the corresponding properties of Samples that are spectrally detected with known dyes.

As detailed above, the photoreactive Crystals are used as a light-sensitive material component of a photographic emulsion. By doing they are introduced into a suitable binder and the emulsion prepared in this way according to one of the methods in the art

ι ··· Manufacture of national products based on processes and processes.

The photographic crystal composition of the photographic emulsion consists of the above preferably a silver compound composed of the crystals, for example composed of one or more Silver halogen shops such as SÜberchlorld. Silver iodide, silver bromide, or from mixed silver halides, such as silver

Chloridbromld, Silberjodldbrotnld or Sllberjodldchlorldbrotnld in different halide ratios. The photographic emulsions prepared in this way can be used for the production of orthochromatic, panchromatic and infrared sensitive photographic recording materials.

The prepared emulsion can be coated on rigid or flexible supports of various types, for example on glass, paper, metal, polymer layers made of synthetic materials as well as natural occurring products. Particularly suitable materials for this purpose include paper; Aluminum; Polymethacrylic acid. their methyl and ethyl esters, vinyl chloride polymers; Polyvinyl acetate; Polyamides, such as nylon; Polyesters such as the polymers obtained from ethylene glycol terephthalic acid; polymers Cellulose derivatives such as cellulose acetate, triacetate, filtrate, proponate, butyrate, acetate butyrate or acetate proponate; Polycarbonates and polystyrene.

The emulsions can be various additives or according to the known technical process Contain additives, for example, quaternary ammonium compounds that increase sensitivity, wl & they are described in US-PS 22 71623, 22 88 226 and 23 34 864, or according to Art the polyethylene glycol compounds described in US-PS 27 08 162. or combinations of the above Substances, as stated in US-PS 28 86 437 1st, or compounds of the type of Thlopoipolymer, which in U.S. Patents 3,046,129 and 3,046,134 are described.

But it is also useful to stabilize the emulsions, namely with the salts of noble metals, such as ruthenium, rhodium, palladium, iridium and platinum, as described in US Pat. No. 2,566,245 and 2,666,263, with the Mercury compounds of U.S. Patents 2,728,663, 2,728,664 and 2,728,665; with the triazoles of US Pat. No. 2,444,608; with the azalandes of US-PS 24 44 605, 24 44 606, 24 44 607, 2444609, 24 50 297, 27 13541, 27 16062, 27 35 769, 27 43 181, 27 56 147 and 27 72 164; with the compounds mentioned by Birr In Scientific Photographies, Sand 47, 952, pp. 2 to 28: with tin Dlsulflden of BE-PS 5 69 317; with the benzothlazolium _{compounds of US Pat.} Nos. 2,131,038 and 2,694,716; with the zinc and cadmlum salts of US Pat. No. 2,839,405, and with the mercapto compounds of US Pat. No. 2,819,965.

Hardening agents can be incorporated into the emulsion, such as inorganic agents with polyvalent metal atoms, in particular those which release aluminum or chromium ions as polyvalent ions, such as potassium alum [K ₂ Al ₂ (SO ₄ ) * · 24H ₂ O] and chrome alum IK ₂ Cr ₂ (SO ₄ ) * · 24H ₂ O], or also organic agents of the aldehyde type, for example formaldehyde, glyoxal and mucochloric acid; also of the ketone type, such as dlacety; quinone type; and the agents recited in U.S. Patents 2,080,019, 2,725,294, 27,25,295, 27,25,305, 2,726,162, 27 * 32,316, 2950,197 and 28,70,013.

The emulsion can also contain one or more such substances, such as, for example Saponin, a polyethylene glycol according to US-PS 28 31 766, a polyethylene glycol ether according to US-PS 27 19 087, a taurine according to US-PS 27 39 891, a maleoplmarate according to US-PS 28 23 123, a Amino acid according to US-PS 30 38 804, a sulfosuccinamate according to US-PS 29 92 108 or a polyether according to US-PS 26 00 831. The emulsion may further contain a gelatin waxing agent such as glycerin, a Dlhydroxyalkan according to US-PS 29 60 404, a Blsglykolsäureester according to US-PS 29 04 434 a Succinate according to US Pat. No. 2,940,854 or a polymeric hydrosol according to US Pat. No. 2,852,386.

The above-mentioned gelatin can be used as a binder for the photosensitive crystals in whole or in part be replaced by another colloidal substance, such as albumin, casein or zein, or by Resins such as cellulose derivatives and vinyl polymers such as these are readily available in a variety is described in foreign patents.

The photographic emulsions can be used for black and white or for color photography for additive as well as R> r subtractive color systems, e.g. In Photography, Its Materials and Processes (as described above).

The finished emulsions can also be used in processes of silver salt diffusion transfer as described in the following US-PS: 23 52 014, 25 00 421, 25 43 531, 25 63 342,

25 65 376, 25 84 029, 25 84 030, 26 03 565, 26 16 807, 26 35 048, 26 44 756, 26 47 055, 26 62 822, 26 98 236,

26 98 237, 26 98 238, 26 98 245, 27 02 244, 27 04 721, 27 40 715, 27 59 825, 27 74 667, 28 23 122. 29 23 623, 29 38 792, 29 62 377, 2984 565, 3003 875, 3043 690, 3087815, 30 87816, 3091530, 3108001 and 3131866; also in the context of methods of additive color diffusion transfer, as described in US Pat. No. 2,614,926,

27 26 154, 29 44 894, 29 92 103 and 30 87 815 are described, and under procedure of subtractlven Color diffusion transfer as described in the following U.S. Patents: 25 59 643, 26 00 996, 26 14 925. 26 47 049, 26 61293, 26 98 244, 26 98 798, 27 74 668, 28 02 735, 28 55 299, 28 92 710, 29 09 430,

29 68 554,

30 19 124, 30 69 264. 33 64 C2 ?, 35 73 043.

2983605, 2983606, 2992 104, 2992 105, 2992 106, P.997'90, 3003872, 30 15501, 30 19 104,
30 22 166, 30 27,167, 30 39 869, 30 43 689, 30 43 692, 30 44 873, 30 47 386, 30 65 074. 30 69 262,
30 76 808, 30 76 820, 30 77 400, 30 77 402, 3148 062, 32 27 550. 32 27 55 '. 32 27 554, 32 43 294,
34 43 939, 34 43 940, 34 43 941, 34 43 943, 34 15 644, 34 15 645, 34 15 646, 34 73 925. 35 73 042,
25 73 044, 35 76 625 and 35 76 626.

The photosensitive crystals according to the invention can also be used as a component of binder-free recording material ^ Find use, for example, in US-Pi, 29 45 771, 31 42 566 and 31 42 567 are described, also in Newmann, Comment on Non-Gelatin Flim, B.J.O.P., 534, September 15, 1961, and In BE-PS 6 42 557 and 6 42 558.

As is known in the photographic art, one can graph the concentration of the photographic material Emulsion-forming silver halogen crystals and the relative structural parameters of the emulsion layer, for example the layer thickness, depending on the type of photographic recording material desired and vary widely according to the intended use.

In conventional photographic processes, silver images are built up through selective exposure a photosensitive photographic emulsion layer which generally has the above-mentioned light-

sensitive silver halide crystals, creating a latent image. The latent image so formed is developed to form a visible silver image by contacting it with a developer solution known in the photographic art. To increase the stability of the resulting visible image, this image can be fixed in a suitable manner by one of the methods likewise known to the person skilled in the art. The image obtained in this way can then be used immediately or, if desired, if this is considered, serve as a negative image, for example in order to generate a reverse or positive image by one of the customary contact or projection copying processes using a suitable photosensitive copy paper.
In the common subtractive color photographic processes which have been widely used commercially in

ίο are used, color coupling methods are generally used in order to achieve the required Generate number of congruent color images as required for monochromatic and multichromatic reproduction will. According to these methods, one takes a selective exposure of one or more selectively light-sensitive, mostly gel-containing silver halide substances, in order to build up the image information of a to enable latent image according to the color value of the selected object. The so obtained

is latent images are appropriately catfish through selective close contact between one or more Developed color developers and one or more color formers or couplers, whereby one develops the necessary Negative color pictures received. But there is also the alternative of developing the latent images, in order to obtain visible silvery images, whereupon these visible images are removed, what is left behind the rest of the silver halide is exposed and the second lightning information is exposed through selective contact between one or more color developers and one or more color formers or couplers In Presence of the exposed silver halide developed in order to obtain the desired colored positive image.

In the case of the diffusion transfer process, an exposed, light-sensitive, mostly gelatin-containing silver halide emulsion containing latent image developed and it is made essentially simultaneously with the development process by the reaction of a silver halide solvent a soluble silver complex with the unexposed and undeveloped silver halide of the emulsion obtain. This soluble silver complex is at least partially towards a suitable copy-receiving Elements transported, whereupon the silver of the complex in this element is precipitated to in this way to create the desired positive image with its individual picture elements.

Additive color rendering can be achieved by using a light-sensitive silver halo

genldemulslonsschlcht exposed by an additive color raster, the filter media or raster elements respectively with an individual addition color, such as red, blue or green, shows what you «resulting image viewed after developing through the same or a similar caster element. If desired, it can light-sensitive marking materials also serve analogously to the diffusion transfer process described above to generate a picture, whereupon the image obtained by the same or by a

^J5 similar additive color raster can be considered which is brought into a suitable registration position with the image carried by the copy-receiving element.

A subtractive color rendering can be achieved by diffusion transfer processes by one light-sensitive, spectrally sensitive silver halide material or several such recording materials associated with a suitable subtractive color providing material is selectively exposed to

* ° to effect the necessary structure of the image format ions of a latent image in accordance with the color value of the selected object, the distribution of the color-absorbing materials being controlled imagewise by diffusion on a suitable image-receiving element depending on the image format ions of the latent image in question. The particularly preferred dye-absorbing materials include the materials forming a dye image which are suitable for producing a uniform distribution of the diffusional dye as a function of the respective degree of point exposure of the photosensitive recording material, and in particular those materials which form a dye image which contain a dye and a developer or is a reducing agent for silver halides which is suitable for bringing about a uniform distribution of the diffusional pale dye in accordance with the unexposed areas of the photosensitive recording material. A variety of such preferred dyes are described in U.S. Pat. No. 2,983,606 mentioned above.

The photosensitive materials according to the invention are, however, not only selectively sensitive, light-sensitive material components suitable, as they are generally for multicolor reproduction according to the principles The subtractive color photography can be used, but they are also particularly suitable for use in creating a panchromatically sensed silver halide emulsion that In particular also for color reproduction according to the above-mentioned diffusion transfer techniques for additive Multicolor rendering may be considered. In detail here is one created by the invention panchromatic silver halide sublons through a common additive color grid with several Filter media or sets of raster elements exposed, each provided for a single addition color such as red, green or blue, and after developing such an image, this can be done from the

w Dlffuslon transfer process resulting photographic image through the same or a substantial one similar grid elements are considered, which are brought into a congruent position in suitable catfish became.

According to the teachings of the above-mentioned US Pat. No. 2,614,926, the construction of the positive Sllbertransportblldes be carried out by a diffusion transfer reversal process for multicolor additive rendition in which a

<· "'Exposure of a silver halide emulsion layer through an additive color raster is provided, whereupon the Emulsion layer is separated from the rest of the recording material after processing, while the Filter media and the receipt are kept in a fixed arrangement, but there is also the clnrs Uirrnaiivx learn *, »ic it is disclosed in the above US-PS 27 26 154 and 29 44 894, the

relate to a diffusion transfer reversal process in which an exposure of a uniformly constructed Multilayer arrangement through a grid with a multitude of tiny optical elements, the light-sensitive and carries light-receiving layers, is provided. As in the patents mentioned is carried out, the transfer processing of the exposed recording material can be carried out in the catfish be that the exposed, integrated recording material with a liquid Verarbcliungs- s soaked in the mass, whereby the image-receiving layer during the construction of the necessary over-flow image and Following this, in a permanently fixed arrangement on the grid is held and it is the The user is free to use the light-sensitive layer after the transfer image has been built up about separating the recording material.

The photosensitive crystals according to the invention can also be used as a photoconductive component electrophoton> Find graphic materlallen use, for example as a component of inorganic photoleltender Crystals, such as the crystals of Z'.i'koxlds, Selenium, Cadmlumsulflds, Cadmlumtellurlds. Indium oxide and Anthracene, sulfur, benzine, the aromatic furans of US-PS 3140 946, as described in US-PS 29 87 395, 30 47 384, 30 52 540, 30 69 365, 31 10 591, 31 21 008, 31 25 447 and 31 28 179 are listed.

To produce the photoconductive layers, the usual procedure is that the photoconductive crystal material is suspended in a suitable solvent in the presence of an electrically insulating binder, whereupon the spectrally sensitive dye is dissolved in this approach before the layer is applied to a conductive substrate. If the layers are produced in this way, the spectrally specific silicon particles of the invention are added in the manner described above before the layer.

There is also the alternative possibility of first producing a non-sensitive photoconductive layer and then to spectrally scan the coating according to the alternative method described above.

As binders for the production of the photoconductive layers, polymers are preferred, which are a fair amount have high dielectric strength and have good electrical insulation in this form, Schlchtblldenoe Represent carrier substances. Substances of this type include styrene-butadlene copolymers; Silicone resins; Styrene alkyd resins; Soy alkyd resins; Polyvinyl chloride); Polyvinylidene chloride); Vinylidene chloride; Acrylic III copolymers; Poly (vinyl acetate); Vinyl acetate; Vinylchlorld copolymers; Polyvinyl acetate), such as polyvinyl butyral); Polyacrylic acid and methacrylic acid esters, such as poly (methyl methacrylate), poly (n-butyl methacrylate) and 3 » Poly (isobutyl methacrylate); Polystyrene; nitrated polystyrene; Polymethylstyrene; Isobutylene polymers; Polyester, like Puiy (ethylene alkaryloxy alkylene terephthalate); Phenol-formaldehyde resins; Ketone resins; Polyamides and polycarbonates. Methods of making resins of this type are known in the art. So can, for example, styrene-alkyd resins according to the method described in US Pat. No. 2,361,019 and 2,258,423 getting produced. Binders of a different type, which are also used for the photoconductive layers can include substances such as paraffin and earth wax.

As solvents which can be used for the production of the last-mentioned sizing compositions, are for example available: benzo !, toluene, acetone. 2-butanone, chlorinated hydrocarbons, e.g. B. Methylene chloride and ethylene chloride, ethers, for example tetrahydrofuran, or mixtures of these Solvent. *>

The photoconductive layers can then be applied to a dividing base in a known manner are, for example, by the conventional doctor blade application method, by a whirling process or by dip coating. Although the photoconductive layers sometimes do not require any binder. is it usually advantageous if a certain amount of glue is incorporated into a sizing compound of this type becomes, for which, for example, 1% by weight can be sufficient.

In the production of the sizing compound, good results are achieved if the photoconductor substance In a proportion of at least 1% by weight, based on the total amount of the sizing compound, is available. The upper limit of the proportion of the photoconductor substance is not a critical one Importance to. In many cases, the polymeric substances do not require a binder to act as a layer by themselves to stick to the pad. If a binder is used, it is usually desirable to do so The amount of the photoconductive substance is in the range from 1% by weight to 99% by weight, based on the total amount of the sizing compound holds. A reserved area for the bulk of the photoconductor substance in the sizing compound is from 10 to 60 wt .- * ,.

The thickness of the coating of the photoconductive mass on a substrate can be chosen very differently be. Normally it is expedient to apply a wet coating in the thickness range from 0.025 to 0.25 mm to undertake. A preferred range of wet coating thicknesses may be from 0.05 to 0.15 mm.

Any electrically conductive substrates can be used as suitable carrier materials for the photoconductive layers according to the invention, such as, for. B. paper (at a relative humidity above 20%), alumintum paper laminates, metal foils such as aluminum foil and zinc foil, metal plates, for example made of aluminum, copper, zinc, brass and galvanized plates, regenerated cellulose and cellulose derivatives and ω certain polyesters, especially those with a thin electrically conductive layer, for example made of cuproiodide.

The photoconductive recording materials can also be used in any of the known electrophotographs Methods are used for which photoconductive layers are required. A such a method is the xerographic method. One method of this type is electrophotographic Recording material is given an electrostatic charge blanket by subjecting it to a corona discharge exposes, which serves to uniformly charge the surface of the photoconductive layer. This cargo is of the layer because of its pronounced IsqHerel property, namely because of the low dark conductivity

λ \ D /

kelt. maintained. The electrostatic charge formed on the surface of the photo-holding layer then becomes by exposure through a negative In the course of a usual barking process, for example after a Contact copying method or by lens projection of an image, selectively derived so as to be in the photo-containing Layer to create a latent image. With the exposure made in this way, the surface comes therefore a charge image comes about because the light causes the charge to correspond to the intensity of the Illumination of the individual places is derived. The charge image remaining after exposure becomes then developed, d. H. made visible by treating it with a medium that is electrostatic Contains attractable particles with blackening power. The electrostatically attractable ones used for developing Particles can be in atomized form, i.e. as a powder, in the form of a pigment in a resinous form Carrier substance, d. H. as a toner, or a liquid developer can also be used, in which the Development effect-imparting particles suspended in an electrically insulating liquid carrier are. Development methods of this type are well known and are in the relevant patent literature described, for example in US-PS 22 96 691. If you choose in the context of a method for electrophotograph Reproduction, also in xerography, a developer material with particles, one of which If the component is a low-melting resin, the developed photoconductive material can be heat-treated and the powder can be made to adhere permanently to the surface of the photo-retaining layer adheres. In other cases, a transfer of the image built up on the photo-containing layer can occur a second document is made, which is then the final copy. Methods of this type are after Prior art is known and are for example in US-PS 22 97 691 and 25 51582 and In »RCA

Review ", Vol. 15, 1954, pp. 469-484.

The invention is to be explained in more detail with reference to the following exemplary embodiment, In which a typical production process of the recording materials according to the invention is described, yes the invention is in no way limited to the details given here, as this is only for the purpose of It is intended to serve as an illustration.

"For the production of a spectrally sensitive gelatin silver halide demulslon containing, for example, 8% silver halide, calculated as silver, and containing 8% gelatin (composition by weight), or their Percentage ratios In other Welse are to be determined, one can proceed in such a way that one is light-sensitive Silver halide emulsion, which is prepared in the above catfish, and which, for example, 9.5% silver halide, calculated as silver, and containing 9.5% gelatin, at 38 ° C with an aqueous solution of a mustard coloring agent added, which is able to deliver the desired concentrations. The emulsion thus obtained can then mixed with a dispersion of the selected inorganic semiconductor and with an amount of water sufficient to form an emulsion with a content of, for example, 4.4% silver halide and 4.4% To deliver gelatin or with other content to be selected, whereupon this emulsion as a layer a customary transparent base is applied to then in this form for further use In the to be available.

In particular, the following sensing dyes were used to illustrate the invention chosen:

I-C = CH

(CHJ ₃ SO ₃ H

CH ₃

CH ₂ COOH

C ₂ H

(CHJ ₃ SO ^

Br

2 "5

H ₃ C

= CH

> CH-C = 1 I C ₇ H,

(CHj) ₃ SO ₃ H

CH-CH = CH

C ₂ H ₅

, Θ

IV ί

H ₃ COCHN

(C Hj) ₃ SO ₃ H

(CH ₂ ) ₃ SO;

^ -NHCOCH ₃

The table below illustrates in particular the advantages and advantages to be achieved by the invention contains information on the composition of the emulsions prepared according to the above procedure, whereby the photographic results obtained with these are listed in each case. Be: dern PbO of the tabular Installation is orthorhomblian lead oxide.

Specifically, the procedure was that the photosensitive recording materials prepared in the above catfish Exposed in a stepped spectrometer and according to the above described transmission method using a commercially available processing reagent and an image receiving agent Elements have been processed.

Tabel

Emulsions
composition Sensitizing dye
and salary
(mg / g Ag) 4.0 inorganic semiconductor
and salary
(g / g Ag) 1.04 Shift sensitivity
compared to the blank sample
(no semiconductor).
Specification in aperture units AgBr 1, 4.0 PbO, 1.04 Increase by about 3 AgBr III, 4.0 PbO, 0.26 Increase by 2 to 3 AgBr IV .. 4.0 PbO. 1.04 Increase by 1 to 2 AgBr II, 2.0 PbO, 0.94 Increase by 2 to 3 AgBr I, 2.0 AlAs, 0.6 Increase by about 1 AgBr I, 2.0 Ge, 0.21 Increase by about 1 AgBrJ (4% J) I, 2.0 PbO, 0.38 Increase by 1 to 7 AgBrJ (4% J) I, 2.0 As B, 0.95 Increase by 1 to 2 AgBrJ (4% J) I, 2.0 AlAs, 1.48 Increase by 1 to 2 AgBrJ (4% J) I, 2.0 TeO ₂ , 1.10 Increase by about 'Λ AgBrJ (4% J) I, 4.0
1.5 Sn, 0.42 Increase by about Vi AgBrJC! (3% J,
85% Br, 12% Cl) I,
HI, 2.0 PbO, 0.42 Increase by 2 to 3 AgBrJCl (3% I,
85% Br, 12% Cl) V, 2.0 PbO, 0.57 Increase by about 2 AgBrJCl (3% I,
85% Br, 12% Cl) I, ZnO, Increase by about Vfc

Similar advantageous results were also achieved with the test methods if instead of those described above Sensing dyes used a large number of other dyes and worked with silver halide systems containing a binderless silver halide as a photosensitive substance; so it showed For example, when using a PbO money solution, which is mixed with a Sensiblllslerungsmlttel der Formula IV coated, vapor-deposited AgBr, an increase in sensitivity accordingly half a strip unit if exposure and processing are carried out in the manner described above was made.

Use the effectiveness of the incorporation of an inorganic semiconductor into a for photographic purposes

The superhalogen material can be seen from the graphical representations of the figures. At Flg. 1 acts |

it is a graphic representation of the activity spectra of a silver iodochlorobromide emulsion (about 3% ξ

J, about 12% Cl and about 85% Br) containing about 4 mg of the sensitive dye of formula I per gram

s was silver-plated. Flg.2 is the graphical representation of the activity spectra of the same emulsion as in Fig. 1, however, in this emulsion an inorganic semiconductor in a molar ratio of about S: 1 (Silver to orthorhombic PbO) had been introduced. The effects show in the utilization the incident radiation to build up the silver image in the entire wavelength range is a significant gain.

ίο In another embodiment, the sensitizing dye and the inorganic semiconductor combined with each other and then added to the silver halide emulsion. Unexpected catfish left the Spectrum of activity in comparison to pure dye exposure an increased sensitivity both in the Detect the natural range of the silver halide absorption as well as the spectrally sensed range. It could also found that the sensitivity of a premixed formulation of a dye and of an inorganic semiconductor put emulsion In its own range was higher than that of the original, not Sealed emulsion. This phenomenon is particularly surprising as it is commonly believed was that the means used for spectral sensing were at least to a limited extent one

Effect desensitization in the crystal's own area of light sensitivity. The effectiveness of the premixed formulation containing the sensitizing dye and semiconductor

results from the comparison of the graphic representation in FIG. 3 with wing. 1 and 2. In Fig. 3 it is is a graphic representation of the spectrum of activity of an emulsion of the same composition as in Figure 2, however, with the sensitizing dye and PbO prior to addition to the silver halide emulsion were premixed. With regard to the increased sensitivity, it should be noted that this increased sensitivity is achieved in the natural range of the absorption of the silver halide crystal and not at the expense the sensitivity achieved in the range of the spectral sensing goes.

Changes can be made to the above product, which are also within the scope of the Invention fall, and details are in the above description as well as in the accompanying drawings not to be construed in a limiting sense of the invention.

For this purpose I sheet drawings

Claims (10)

Patent claims: 1. Photosensitive recording material with a dispersion of photosensitive crystals, consisting of photosensitive metal halides or organic or inorganic photoconductors that Depending on exposure to actual radiation are reducible, and at which a spectrally Sensllislerender dye, possibly with the addition of a supersensitizer, is adsorbed, as well as with a Content of an inorganic semiconductor, characterized in that the inorganic semiconductor Assigned to donate electrons to the light-sensitive crystals depending on an exposure is, his Leltfählgkeltsband-Energlenivsau Q lies above that of the light-sensitive crystals, In his band scheme has a larger band gap ("forbidden band") than the spectrally sensitive dye and a higher Fermin level than the spectrally sensitive dye and / or the light-sensitive crystals in the case of silver halide as light-sensitive crystals, a molar ratio of silver halide to semiconductors from 1: 1 to 100: 1. 2. Recording material according to claim 1, characterized in that the inorganic semiconductor is PbO (orthorhomblsch). Ge, AISb. ZnSe, AlAs, GaAs, InAs, In ?, GaP, GaSb, Sn, Sl. Ge, SnS is present. 3. Recording material according to claim 1 or 2, characterized in that the spectrally senslbillslerende Dyestuffs Leltfählgkeltsband energy level above that of the light-sensitive crystals. 4. Recording material according to one of claims 1 to 3, characterized in that as spectral The sensitizing dye is a cyan dye of the following formulas: ^s \ > = CH - C = < N / I (CH ₂ ) ₃ SOjH CH ₃ (CHJ ₃ SO CH ₂ COOH C ₂ H ₅ V = CH-C = N / I IC ₂ H ₅ (CH ₂ J ₃ SO ₃ H (CH ₂ ) JSO ₃ Θ CH ₃ C ₂ H ₅ V = CH-CH = C ₂ H ₅ C ₂ H ₅ C ₂ H ₅ ci Cl . J H ₃ COCHN (CH ₂ ) ₃ SO ₃ H (CHj) ₃ SO ₃ Θ NACOCH ₃ 5. Recording material according to one of claims I to 4, characterized in that the light-sensitive Crystals of silver halide are present. 6. Recording material according to claim 5, characterized in that the silver halide is Sllberjodldbromld or Sllberjodldchlorldbromld is present. 7. Recording material according to one of claims 1 to 6, characterized in that the inorganic Semiconductors and the Photosensitive Crystals In your band scheme a larger band gap ("Forbidden band") as the spectrally sensitive dye. 8. A method for producing a recording material according to any one of claims 1 to 7, characterized characterized in that first a mixture of the dispersion of the photosensitive crystals and the spectrally sensitive dye and then the inorganic semiconductor of this mixture clogs. 9. A method for producing a recording material according to any one of claims! to 7, thereby characterized in that first a mixture of the spectrally sensitive dye and the inorganic Manufactures semiconductors and this mixture then the dispersion of the photosensitive crystals > o adds. 10. Use of a recording material according to one of claims 1 to 9 in a diffusion transfer process.