DE2220597A1 - IMPROVED PHOTOGRAPHIC MATERIAL - Google Patents

Description

2 B-. APP. 107;

AG FA- G EVAERT AG

^{PATENT DEPARTMENT}
za-mka Leverkusen

Improved Photographic Material

The invention relates to a photographic material for manufacture photographic copies by the dry route with a content of toners for obtaining black silver images. The invention relates to furthermore a photographic thermal copying process, whereby the production of the silver image takes place in the presence of toners, which shift the image tone from yellow to black-brown to black.

In the case of the one described in German Patent 1,300,014 Copying methods are used recording materials containing an oxidizing agent, a reducing agent and a smaller one

_A _ _{G 961} 309846/0608

Amount of a photosensitive compound contained. A redox reaction forms a colored image on the exposed areas and subsequent heating. Organic silver salts are used as oxidizing agents, and aminophenols, hydroxylamines, pyrazolidones or phenols are also used as reducing agents, phenylenediamine or etherified naphthols, for example _o- 4-methoxynaphthol-1. Heavy metal salts which form traces of the free metal on exposure are suitable as photosensitive compounds; In particular, they are light-sensitive silver salts, for example silver halides, which photolytically form silver on exposure. The redox reaction is initiated by these photolytically formed heavy metal nuclei.

The use of light-insensitive silver salts as oxidizing agents is essential for the practical use of such materials, such as silver saccharide, or silver salts of long-chain fatty acids. Particularly high light sensitivity is then achieved when the required silver halide on the surface of the light-insensitive silver salt by reaction with halide ions or a compound which forms halide ions, e.g. according to that in German Offenlegungsschrift 1 572 203 described method is generated. These materials have a corresponding sensitivity in the short-wave part of the spectrum the inherent sensitivity of the silver halides used and can be achieved by adding spectral sensitizing dyes also be sensitized to long-wave light.

It is also a method of making photographic Copies known by the dry route, being a photographic material containing a silver salt and a reducing agent for this Contains silver salt, is exposed imagewise and the heating of the exposed material is carried out to a temperature at which the reducing agent reduced the silver compound in the exposed areas to form a visible silver image In this method, a photographic material having a layer which is one under the conditions of the method is used

A-G 961-2- 309846/0608

essentially light-insensitive silver compound, a reducing agent and a polymethine sensitizer for spectrally sensitizing the non-photosensitive silver compound.

With these methods - if suitable measures are not taken - only yellow to light brown silver images of low contrast are obtained. A better contrast can be achieved by increasing the amount of reducing agent in the materials used. However, the measure has the following disadvantages: The amount of reducing agent present in the photosensitive material must be kept to a minimum in order to avoid undesired darkening of the casting solution or the layer, ie a reduction of the organic silver salts during the production and storage of the material, , Therefore, these materials are preferably weak reducing agent of the type of o-alkyl-substituted phenols are added as they are described for example in German Offenlegungsschrift 1,908,761 _o

It is known, in order to obtain images with sufficient optical density, which provide sufficient contrast in the finished copy result in adding so-called toners to the light-sensitive layers, which shift the image tone from brown to black. Such a compound is, for example, 2H-phthalazinone- (1). This toner, in combination with some silver salts, causes and Reducing agents a darkening of the casting solution or the Materials, which limits its usefulness.

The invention has for its object to provide toners for those described above to develop photographic processes that shift the image tone of the silver image to black without compromising stability to deteriorate the material during manufacture or storage by darkening.

A-G 961-3-309846/0608

BS has now found a photographic material for the production of photographic copies by the dry route with a light-sensitive layer which contains essentially light-insensitive reducible silver salts, a light-sensitive heavy metal compound and / or a polymethine sensitizer for the spectral sensitization of the light-insensitive silver compound and reducing agent and which is characterized by a content of a compound of the following formula:

S ο

⁰ ^ NC-NH-R

where mean:

R β (1) alkyl with preferably up to 5 carbon atoms, where the alkyl group can optionally be substituted , for example with alkoxy or phenyl, as in the case of benzyl or phenylethyl, (2) aryl, in particular phenyl, which can optionally be substituted with Alkyl or alkoxy with preferably up to 5 carbon atoms, carboxyl, esterified carboxyl or nitrile, (3) a heterocyclic group which can optionally be substituted or (4) an acyl group which is derived from aromatic sulfonic or carboxylic acids, e.g. arylsulfonyl , preferably phenylsulfonyl, or benzoyl.

The following compounds, for example, are suitable:

A-G 961 -4- 309848/0608

N-CONH N

0 it

N-CONHCO-

Il

^ N-CONH-

c-

J-CONH

-CH,

O ir C

^ N-CONH- (CH ₂ ) ₁₇ .CH ₃

C H

A-G 961

30 98 46/0608

Usable are ζ. B ₀ Compounds of the above general formula which contain 2 phthalazinone nuclei which are connected in the 2 positions by a -CO-NH-X-NH-CO group, where X is a divalent organic group, for example alkylene or arylene. The phthalazinone derivatives of the above general formula are prepared by methods known per se, for example by reacting phthalazinone with an isocyanate. The preparation of compounds 1 and 2 is described below. Others of the phthalazinones to be used in the manner according to the invention are obtained in an analogous way.

Connection 1

A mixture of 146 g (1 mol) of phthalazinone and 138 g (1.1 mol) of phenyl isocyanate in 2 l of dry benzene is boiled for 4 hours with stirring. The solution is then cooled and the precipitate formed is filtered off with suction. This precipitate is washed with dry diethyl ether,
Yield: 93%. Melting point: 154-156 ° (decomposition).

Connection 2

To 146 g (1 mol) of phthalazinone, dissolved in 2 liters of boiling dry toluene, 147 g (1 mol) of benzoyl isocyanate are added over the course of 15 minutes. The reaction product precipitates in the boiling solution. This reaction mixture is kept at the boiling point with stirring for 1 hour. It is then cooled, whereupon the precipitate formed is filtered off with suction and washed with toluene.
Yield: 85 %. Melting point: 179 °.

Those according to the invention containing a phthalazinone derivative Photographic materials are used for the above-described processes for making copies by the dry route.

A-G 961 - 6 - 309846/0608

By adding the phthalazinone derivatives, the image tone becomes the Silver images shifted in the desired way from yellowish-brownish to black to blue-black. The stability of the Casting solutions for the layers and the stability of the layers themselves are not detrimental to the addition of these toners influenced. There is no brown discoloration. In addition, surprisingly, the photographic Properties such as developability compared to the toner-free Materials stabilized »especially under unfavorable conditions, such as higher temperature and humidity, i.e. tropical conditions.

In the first method, photographic material is used with a layer which contains a light-insensitive silver salt and generally a small amount of light-sensitive heavy metal salt, in particular a silver salt, as well as a reducing agent to reduce the silver salts at the exposed areas.

In the second process, a photographic material is used with a layer which, under the conditions of the process, contains essentially non-photosensitive silver compound, reducing agent and a generally small amount of a polyethylene sensitizer for the ipral sensitization of the non-photosensitive silver salt. This procedure is in the German patent specification. . ". = .. (P 21 40 462.6).

The sensitizers are generally used in organic solvents dissolved added to the casting solutions described below. The addition can also be made in solid form to the silver salt the grinding or shortly before the application of the casting solution on a carrier. The concentration of the sensitizer in the layer can vary within wide limits. She judges according to the desired effect and the type of sensitivity

A-G 961 -7- 309848/0608

sators in combination with the silver salt. In general, concentrations of 0.1-2g of sensitizing dye, preferably 0.2-0.6 g per mole of silver salt has been found to be sufficient. In individual cases, the sensitizers can also be used in Amounts outside this range can be added.

The toners to be used in the manner of the present invention are preferably added to the light-sensitive layer. However, some of them can also be added to an adjacent layer.

The compounds to be used in the manner according to the invention can be added to the layers in various amounts. The optimal amount depends on the desired effect and the Layer composition from. The optimal amount can go through a few simple experiments familiar to the average person skilled in the art can be found. In general, additions of 0.5-6 moles, preferably 1-4 moles, of the phthalazinone derivative per mole of the light-insensitive silver compound, preferably an organic silver salt, proved to be sufficient.

The phthalazinone derivatives to be used in the manner according to the invention can also be used in a mixture with known toners. The concentration of the additional toners is preferably lower than that of the present invention. Reference is made to the unsubstituted phthalazinone, phthalimide or phthalimide derivatives, for example those in the German patents. . " . .. (P 21 40 462) and. ... ... (P 21 40 063).

The toners to be used in the manner of the present invention can be used in combination with those for the respective heat development process or known for the photosensitive copying material Materials and compounds, e.g. reducing agents, binders, silver salts and other heavy metal salts, white pigments and stabilizers are used. Such materials are known per se and, for example, in the following patents described: German Offenlegungsschriften 1 300 014, 1 547 878, 1 572 203, 1 908 258, 1 908 761 and German patent applications P 20 20 639 * 6 and 20 31 748.0.

3 0 9 8 4 6/0608

A-G 961 - 8 -

Contain organic reducing agents known for these processes active hydrogen bonded to 0, N or C, such as o-alkyl-substituted Phenols, di- and trihydroxyaryl, aminophenol, aminonaphthol, p-phenylenediamine and hydroxylamine derivatives, Alkoxynaphthols, acetoacetonitriles, pyrazolidin-3-one and Pyrazolin-5-one, indanedione-1,3, ascorbic acid and hydroxychroman- or hydroxycoumaran derivatives, e.g. according to the German patent (P 20 31 748.0); e.g. o-alkyl-

substituted phenols, hydroquinone, aminophenol and methoxynaphthol derivatives.

In the variant of the material according to the invention in which light-sensitive heavy metal salts, in particular silver salts, are present as light-sensitive compounds, the layers can also be optically sensitized by adding dyes. As sensitizers, the compounds are preferably suitable which are also commonly used for optical sensitization of conventional silver halide emulsion layers, ie _o cyanine Merocyanines Qxonole or rhodacyanines of various kinds, as for "B _o in the book of FM HAMER in" The Cyanine Dyes and Related Compounds "(1964) are described.

For the preparation of the material according to the invention, the components for the redox reaction and the photosensitive heavy metal together with a suitable binder used "As the binder, the conventional natural or synthetic film-forming polymers are, for example proteins _s particular gelatin, cellulose derivatives, especially cellulose ethers ₉ Celluloseester or carboxymethylcellulose, Alginic acid and derivatives thereof, starch ether or galactomannan5. Preferred binders are organic polymers, such as copolymers of vinyl chloride and vinyl acetate or of butadiene and styrene, polyethylene, polyamides, polyisobutylene ^ polyvinyl chloride _s poly

A-G 961 - 9 - 309846/0608

vinyl alcohol, polyvinyl acetate or wholly or partially saponified polyvinyl acetate, polyvinylidene chloride, polyvinylpyrrolidone, polystyrene, chlorinated rubber, polyvinyl butyral, polymers of acrylic or methacrylic acid esters, acrylamide or copolymers of derivatives of acrylic acid and methacrylic acid, cellulose derivatives such as nitrocellulose, cellulose acetates, cellulose propionates or mixtures thereof, such as cellulose acetobutyrate et al.

The photosensitive layer can be used as a self-supporting layer, but it is preferably applied to a suitable layer support. The layer support must be ^{stable between 60 and 200 °} C. at the processing temperature. Suitable supports are, for example, sheets or foils made of paper, cellulose acetates, polyethylene terephthalate, textile fabrics, metal foils or glass. In the case of paper carriers, the papers can contain the usual auxiliary layers, such as barite layers, polyethylene layers, etc.

Silver compounds which are largely insensitive to light under the conditions of the process have proven to be particularly useful are, for example, the silver salts of aliphatic carboxylic acids with a Thioether moieties or silver salts of long-chain fatty acids, such as silver behenate, silver palmitate, silver stearate, etc.

As light-sensitive heavy detail salts that are used for the former Processes are suitable and form metal nuclei on exposure which are capable of the image-forming redox reaction For example, inorganic or organic salts of silver, mercury or gold are suitable. Heavy metals are preferred of subgroup Ib of the Periodic Table of the Elements, in particular silver salts and of these in turn preferably silver halides .

The light-sensitive one that is particularly suitable for the respective redox system Heavy metal salt can be determined by a few manual experiments. For example, the metal salt can be used in the form of its aqueous

A-G 961 -10- 309846/060 8

Mix the suspension with the components of the redox reaction, whereby no changes may be made in the dark. will this If the mixture is irradiated with UV, it should change color relatively quickly. If these conditions apply * then the heavy metal salt is for the redox system suitable

The photosensitive heavy metal salt is in relatively low Amounts of about 0.05-0.2% by weight, based on the weight of the Oxidizing agent used. This proportion of photosensitive salt is sufficient for most systems. In exceptional cases can of course fall below or exceed this percentage will.

The light-sensitive heavy metal salt, for example the silver halide, should be present in such small amounts that the photolytically heavy metal nuclei formed can initiate the redox reaction; however, the concentration of silver halide should be so low that that, due to the metal nuclei formed, none or only a negligible one Discoloration of the copy material occurs.

Some of those useful in the context of the present invention light-insensitive silver salts show up when precipitated in the presence of a protective colloid, e.g. proteins, especially gelatine, as is customary in the preparation of conventional silver halide gelatin emulsions is proceeded, a certain - albeit low - intrinsic sensitivity. In the precipitation of the silver salts for the production of the material according to the invention must therefore be proceeded in such a way that the silver salts formed are insensitive to light, This is generally already achieved if precipitation is carried out in the absence of a protective colloid *

The dried silver salts are then added in the solutions or dispersions of the desired layer binder .. The concentration of the silver salt in the binder dispersions may thereby vary within wide limits, depending on the desired silver coverage ^v in the photographic layers ,, In general, amounts of 0.1 - 0.01 mol of silver salt per kilogram of casting solution

A-G 961-11- 3G9846 / 0608

2220537

sufficient. It is preferred to use 0.02-0.04 moles of silver salt per kilogram of the solution or dispersion. The same applies to the silver application in the finished photographic layer. Here, too, the concentration can be varied within wide limits depending on the desired effect of the intended use. In general, the application will be 0.1-1 g of silver in the form of the silver salt per m, preferably 0.3-0.6 g per m ² . Of course, mixtures of different light-insensitive silver compounds can also be used in the context of the material according to the invention.

To improve the photographic properties of the material according to the invention, other light-insensitive heavy metal compounds can be added to the material, preferably to the layer containing the light-insensitive silver salt. In this way one can, for example, _o a reduction of the veil, an increase in the density or a shift in the image tone to desired colors, for example to a neutral black, to achieve.

Suitable for this are, for example, "Salts or compounds of mercury, Cadmium, lead, uranium, gold, platinum, palladium or rhodium. The heavy metal compounds can already be used during the precipitation of the Silver salt can be added. Solutions of the heavy metal salts and the silver salts are preferably used in the double-jet process added to the submitted precipitation component and at the same time precipitated »If the common precipitation of the Silver salt and heavy metal salt is particularly advantageous and, depending on the nature of the ■ heavy metal salt, particularly favorable Brings effects, the heavy metal salts can, however, also in solid or in dissolved form the already containing silver salt Casting solutions for the photographic layer can be added. The heavy metal salts can also be mixed with the dried silver salts be mixed by grinding or added shortly before the casting of the casting solution for the photographic layer «Of course, combinations of different heavy metal salts can also be used.

-G 961-12-3 0 9846/0608

The amount of heavy metal salts or heavy metal compounds added can fluctuate within wide limits “Here too the concentration depends on the type of heavy metal salt and the silver salt and the desired effect »The optimum amount can be determined by a few simple manual experiments of can easily be determined by any average person skilled in the art »The effectiveness the heavy metal salts are often more pronounced when they are co-precipitated. Suffice it to achieve the desired effect here mostly concentrations of 0.001-10 mol%, preferably 0.01-5 mol% o If the heavy metal salts are added at a later stage in the production of the photographic material For casting, concentrations of 0.001-0.2, preferably 0.005-0.07 mol of heavy metal salt, e.g. mercury, are sufficient (II) acetate per mole of silver salt.

The layers can also contain white pigments such as zinc oxide or silicon dioxide or titanium dioxide as fillers, to improve the whiteness and to influence the adhesion of the layers as well contain terpene resins and organic acids to improve storage stability. Such layers are in the American Patent Nos. 3,074,809 and 3,107,174.

To expose the photosensitive layers according to the invention, the light sources customary in reproduction technology, such as halogen lamps, iodine quartz lamps or incandescent lamps can be used. Which light source is used depends on the spectral sensitivity of the heavy metal salt used or sensitizer dye. The exposure time is a few seconds.

The development of the silver salt-containing light-sensitive copying materials takes place in the heat at temperatures between 80 and 200 ⁰ C. The heating can be done by guiding the exposed photosensitive layer

A-G 961-13-309846/0608

via hot plates or rollers or by irradiation with UR light. The photosensitive silver salt containing Material can be used to protect the layer and to create a high-gloss image in contact with a film, e.g. polyester film in which heat is developed. The most favorable temperature and heating time depends of course on the composition of the silver salt photosensitive material. It can be determined by a few simple experiments will"

example 1
Photosensitive material:

A mixture of the following composition is ground for several hours:

1.8 g silver behenate behenic acid (molar ratio 1: 1) a toner in the amount given in the following table 50 mg of mercury (II) acetate

1.5 g cellulose acetobutyrate

0.75 g copolymer of vinyl chloride and vinyl acetate

(Weight ratio 60:40)
26 g of methyl ethyl ketone

0.5 mg of the sensitizer 5- / t3-ethylthiazolidin-2-ylidine) -äthyliden7-3-allyl-2-thio ~ oxazolid.iri "2,4-dione, dissolved in 0.5 ml of methyl ethyl ketone and 1 g of bis (2-hydroxy-3-tert-butyl-5-methyl-phenyl) -methane added.

The casting solution is applied to a paper support and dried. The silver order is. 0.5-0.6 g of silver

ρ
in the form of the silver compound per m ".

A-G 961-14- 309846 / 06C8

Processing:

The light-sensitive material is exposed through a transparent template with tungsten lamps, depending on their intensity and the desired gradation, for 3 - 30 seconds and developed by heating. Depending on the level of temperature of 60 - 16Q ⁰ C and the apparatus used the development time is 3 - 80 seconds. Heatable presses, drying drums, rollers or the devices described in Belgian patent specification 628 174 or French patent specification 1,419,101, 1,416,752 and 1,512,332 as well as commercially available devices can be used as developing devices.

"While without toner, only low density yellow image silver is obtained becomes black images in the presence of the following toners good density obtained.

To protect the layer and to produce a high-gloss image, the layer side of the material can be in contact with a Polyester film can be developed in the heat.

To compare the stability of the materials according to the invention with those which contain known toners, namely the unsubstituted phthalazinone, became test strips of the toner to be tested Contained material tested in the following way: The unexposed strips were with increasing temperature with Incline intervals of 5 ° each developed for 20 seconds. The temperature at which the unexposed was then determined Material shows development to a fog of 0.15-0.2. The higher this temperature, the more stable the light-sensitive one Layer. The results of these investigations are summarized in the following table.

A-G 961 - 15 -

309846/0608

Tabel

g per
approach toner image
volume Skid
temperature 1.9 1 black 110 ⁰ C 1.9 2 black 100 ⁰ C 2.2 3 black 110 ' ⁰ C 2 4th black 105 ° C 2.5 5 black 105 ° C 1 Comparative
substance black 85 C

The light-sensitive material containing the toners according to the invention has better stability and a greater processing latitude due to the fogging temperature which is 15-25 ° higher than that of the phthalazone-containing material. Without any adverse effect on the stability, 0.1-0.2 g of phthalazinone can be added to the layers to accelerate development.

Example 2

The following are applied to a substrate made of barytaised paper Layers applied:

A-G 961

- 16 -

309846/0608

1. Photosensitive layer made from the following casting solution:

1.8 g silver behenate / behenic acid (molar ratio 1: 1) 3.0 grams of cellulose acetate

4.5 ml of a 1% calcium bromide solution in methanol;

5.7 ml of a 1 % methanolic solution of mercury (II) acetate solution, which has been acidified by adding glacial acetic acid,

3.0 ml of a 0.01 solution of 1-methyl-3-allyl-5- / 2- (3-ethyl-b © nzbxazolylidene- (2)) »ethylidene7-2-thiohydantoin in chloroform

0.15 g silica

55, og acetone

1.0 g of a copolymer of vinyl chloride and vinyl acetate (Weight ratio 88:12) dissolved in 20 g acetic acid butylate, 3 g of compound 1 and 0.2 g of phthalazinone

2. Dookachlicht made of the following casting solution:

10.0 f polyvinyl butyral

4 g hydroquinone

1 00 ml of mithanol and

1.5 f dir load no, -1

The Q & ßlösiffig for "the lichtöffipfindlichs layer is milled for 16 hours in a ball mill before the application * The light-

2
The sensitive layer contains 0.7-0.9 g of silver per m in the form of the specified silver salts.

The top layer HUf is applied to the dried photosensitive layer. The concentration of the reducing agent in the top layer is 0.5 - 1.5 g per χά ~ _a

The exposed material is developed in the heat as described in Example 1 and a black image is obtained.

A-G 961-17-309846/0608

/ f

Example 3

Photosensitive material:

An equimolar mixture of silver behenate and behenic acid will be by precipitating syrber nitrate with a solution of sodium behenate and behenic acid made in alcohol and water. The precipitate is carefully washed and dried.

The suspension for the production of the layer is obtained by treating the mixture given below in for 12 hours produced by a ball mill:

240 ml of methanol

125 ml of a 10% solution of polyvinyl butyral in

Methanol
20 ml of a 10% solution of poly-N-vinylpyrrolidone in methanol

30 g of the equimolar mixture of silver behenate and behenic acid 10 ml of a 1 # methanolic solution of ammonium bromide 1.5 g of toner No. 3
15 g 1-phenyl-3-methylpyrazolone- (5)

The above mixture is applied to a standard paper support in a concentration of 100 g / m² and at room temperature dried.

Processing:

The light-sensitive layer is exposed through a transparent original. A 750 watt UV lamp at a distance of 5 cm is used as the light source. The exposure time is 2 seconds, followed by ^{heating to a temperature of 120 °} C. for 5 seconds.
A black negative image of the original is obtained.

A-G 961 -18- 3 0 98 46/0608

Claims (8)

Claims HJ Photographisch.es ATafzeiehnungsmaterial with a light; - " sensitive layer, which is an essentially light-insensitive silver salt, a reducing agent, a toner as well as a light-sensitive SehwermetallverMndung.and / or a polymethine sensitization * for spectral sensitization contains silver compound that is insensitive to lending, characterized in that 'the photosensitive layer contains a phthalazinone toner represented by the following formula in which B. denotes an alkyl, aryl, aroyl, arylsulfonyl or heterocyclic group. 2. Recording material according to claim 1, characterized in that it is a silver salt as the light-insensitive silver salt contains a long-chain fatty acid. 3. Recording material according to claim 2, characterized in ^ net that it contains silver behenate or silver stearate. 4. Recording material according to claim 1, characterized in that the light-sensitive heavy metal compound is a silver halide is included. 5. Recording material according to claim 1, characterized marked- ■ net that the light-sensitive heavy metal compound is contained in amounts of 0.05-0.2% by weight, based on the weight of the light-insensitive silver salt. ^A ~ ^G 961. -19- 309846/0603 6. Recording material according to claim 1, characterized in that the phthalazinone toner in a molar ratio of at least 0.5, based on the light-insensitive silver salt. 7. Recording material according to claim 1, characterized in that R is alkyl, phenyl, naphthyl or benzoyl. 8. Recording material according to claim 1, characterized in that that the photosensitive layer is a photosensitive silver salt, a reducing agent and a polymethine sensitizer for the spectral sensitization of the light-insensitive silver salt 309846/0608 A-G 961 - 20 -