Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C7/00—Multicolour photographic processes or agents therefor; Regeneration of such processing agents; Photosensitive materials for multicolour processes
  • G03C7/30—Colour processes using colour-coupling substances; Materials therefor; Preparing or processing such materials
  • G03C7/388—Processes for the incorporation in the emulsion of substances liberating photographically active agents or colour-coupling substances; Solvents therefor
  • G03C7/3882—Processes for the incorporation in the emulsion of substances liberating photographically active agents or colour-coupling substances; Solvents therefor characterised by the use of a specific polymer or latex

Definitions

• the present invention relates to a process for incorporating water-insoluble to water-insoluble photographic additives into flowable aqueous preparations which contain a hydrophilic colloid and are suitable for the production of photographic layers.
• the organic solvents used can be non-volatile oils, such as tricresyl phosphate, mixtures of alkylated triphenyl phosphates or dibutyl phalate, which remain in the layer after drying in the form of fine droplets containing the solute.
• volatile solvents such as esters, ketones, ethers or alcohols can also be used during drying process with the water from the layer.
• the volatile solvent is removed from the emulsion by evaporation. This takes place partly to facilitate the recovery of the solvent and partly also to increase the storage stability of the emulsion and not to burden the layer composition with excessive volumes of inactive substances.
• German published patent application 2 609 742 proposes to finely grind water-insoluble additives such as sensitizers or stabilizers in the sand mill without the addition of solvents in the presence of dispersants. In this case, the grinding process can also be followed by atomization or freeze-drying in order to achieve a stable dry preparation.
• German Offenlegungsschrift 2,551,841 describes a process in which the water-insoluble substances are dissolved in a fatty acid while melting and then dispersed by introduction into the aqueous solution of a base, it being possible, if appropriate, to add further dispersants.
• the object is achieved according to the invention in that the photographic additives are mixed with a combination of dispersants and then finely distributed in an aqueous preparation of the hydrophilic colloid.
• the invention further relates to the photographic layers produced and to photographic materials which contain these layers.
• the photographic additive can include a dye (for example an image, filter, antihalo or screen dye), a substance providing a dye for the color diffusion transfer process, a chromogenic color coupler, a DIR compound, a stabilizing agent, a spectral sensitizer, a desensitizer, a UV absorber, a light stabilizer, an optical brightener, a solubilizer, a bleaching catalyst for the silver dye bleaching process, a developer or a crosslinking agent.
• a dye for example an image, filter, antihalo or screen dye
• Preferred dispersing agents of the formula (1) are those in which R 1 , R 2 and R 3 are each hydrogen, alkyl having 1 to 5 carbon atoms, cyclohexyl or phenylalkyl having or 2 carbon atoms in the alkyl radical, at least one of these radicals being alkyl having at least 3 Is carbon atoms and the sum of the carbon atoms in these radicals is at least 4, R 4 is hydrogen or methyl and Z is hydrogen or -P (O) Y 1 Y 1 , wherein Y is a radical of the formula is R 1 , R 2 , R 3 and R 4 have the meanings given and n 1 is an integer from 4 to 100, preferably 4 to 60.
• Preferred dispersing agents of the formula - (2) are those in which R 5 to R 8 are each hydrogen or alkyl having 1 to 5 carbon atoms, at least two of these radicals being alkyl having at least 3 carbon atoms and the sum of the carbon atoms in these radicals at least 8 and R 4 is methyl or preferably hydrogen and m 2 and the sum (n 2 + n 3 ) is 8 to 200, preferably 8 to 80 or 20 to 80.
• alkyl radicals in the preferred compounds of the formulas (1) and (2) are in particular straight-chain and branched alkyl radicals with 1 to 5 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl, amyl, isoamyl or tert-amyl.
• Preferred dispersing agents of the formula (3) are those in which R to R 14 are each chlorine or bromine, R 4 is methyl or preferably hydrogen and m 2 and the sum (n 4 + n 5 ) is 8 to 200, preferably 8 to 40 or Is 20 to 40.
• Preferred dispersing agents of the formula (4) are those in which R15 to R17 are each hydrogen or alkyl having 1 to 12 carbon atoms, at least one of these radicals being alkyl having at least 3 carbon atoms and the sum of the carbon atoms in these radicals being at least 4 and R 4 is methyl or preferably hydrogen and Z 1 -SO 3 M, n 6 is an integer from 1 to 50 or 1 to 20 and M has the meaning given.
• the alkyl radicals R 13 to R 17 are, for example, methyl, ethyl, n-propyl, n-butyl, n-amyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl or n -Dodecyl and the corresponding isomers with secondary and tertiary carbon atoms.
• Preferred dispersing agents of the formula (5) are those in which R 18 to R 21 are each hydrogen or alkyl having 1 to 5 carbon atoms, at least two of these radicals being alkyl having at least 3 carbon atoms each and the sum of the carbon atoms in these radicals being at least 8, and R 4 is hydrogen or methyl and m is 2, the sum (n 7 + n 8 ) is 2 to 40 and Z is -SO 3 M, where M has the meaning given.
• alkyl radicals R 18 to R 21 are those which have already been given for the compounds of the formula (2).
• Preferred dispersing agents of the formula (6) are those in which R 22 to R 77 are each chlorine or bromine, R 4 is hydrogen or methyl, m is 2 and Z is -SO 3 M, the sum (n 9 + n 10 ) 2 is up to 40, and M has the meaning given.
• the compounds of the formulas (1) to (6) are compounds which can be prepared by known methods (for example ethoxylation / propoxylation of phenols or bisphenols, optionally followed by esterification) (see, for example, US Pat. No. 3 583,486, 3,659,650 and German Patents 2,300,860 and 1,287,556).
• both ethylene oxide and propylene oxide are added, it is advantageous to add the two alkylene oxides in separate phases so that the alkenoxy chains formed on the phenol groups have separate "blocks" consisting of one or more ethenoxy or propenoxy units.
• the chain length and the ratio of the amount of accreted A and propylene oxide as well as by the chain length, the number and position of alkyl substituents on the phenyl nucleus the properties of the resulting non-ionic dispersants can be controlled within wide limits ethylene. Water solubility and dispersant properties depend largely on the length of the alkenoxy chains and the number of hydrocarbon atoms in the alkyl substituents. To ensure that the compounds are sufficiently hydrophilic, the number of attached propenoxy units should at most be the same size, but preferably less than half the number of ethenoxy units.
• the compounds of the formulas (4) to (6) are prepared by esterifying the compounds of the formulas (1) (if Z in formula (1) is hydrogen) to (3.) with preferably sulfuric or phosphonic acid.
• the preparation of the sulfuric acid esters by reaction with sulfamic acid or sulfur trioxide is described, for example in N. Schönfeldt, "interfacial active ethylene oxvadducts", Stuttgart 1976, p. 919 ff.
• the dispersants of formulas (1) to (3) (nonionic dispersants) on the one hand and those of formulas (4) to (6) (acidic esters) on the other hand are used in weight ratios between 1: 0.01 to 1: 1, preferably 1: 0 , 05 to 1: 0.2 used; the weight ratio between the substance to be dispersed and the dispersant (total of the compound of the formulas (1) to (6)) is chosen between about 1: 0.1 and 1: 4.
• Mixtures of dispersants of the formula (1) and of the formula (4) are particularly preferred.
• the weight ratio between the water-insoluble phase (photographic additive / dispersing aid, optionally solvent) and the aqueous colloid solution is generally between 1: 5 and 1: 100.
• the oily phase is first prepared by adding the water-insoluble photographic additives such as dyes, couplers or UV absorbers in a mixture of at least one dispersant of the formulas (1) to (3) and at least one dispersant of the formulas (4 ) to (6), in particular of formula (4) at room temperature or slightly elevated temperatures (20 to 50 ° C).
• Dispersants in solid form are melted, for example at 40 to 120 ° C.
• a solvent must be added to facilitate the dissolving process.
• water-immiscible solvents with a solubility parameter of less than 13 are suitable.
• solubility parameter see J. Brandrup and EH Immergut "Polymer Handbook", Intersciene Publishers, New York / London / Sidney, 3rd edition 1967, p. IV-341 ff.
• Suitable solvents are e.g. Hydrocarbons, halogenated hydrocarbons, higher alcohols, esters, ethers, nitriles, or ketones, in particular pentane, hexane, heptane, octane, nonane, decane, tetrahydronapthalene, decahydronaphthalene, cyclohexane, benzene, toluene, xylene, chlorobenzene, bromobenzene, dichlorobenzene, methylene chloride , Chloroform, carbon tetrachloride, trichlorethylene, butanol, pentanol, hexanol, cyclohexanol, ethyl acetate, propyl acetate, butyl acetate, amyl acetate, ethyl propionate, cyclohexanone, methyl isobutyl ketone,
• Solvents are generally considered to be fiber because they have no photographic function; one will therefore only use as much of it as is necessary to dissolve the substance to be dispersed in the oil phase or to prevent it from crystallizing out in the dispersion. The approximately ten times the amount by weight of the substance to be dispersed should practically hardly be exceeded.
• the next step in the preparation of the dispersions is to distribute the oil phase in the aqueous phase in such a way that a finely divided oil-in-water emulsion is finally formed.
• this step is carried out without the expenditure of substantial amounts of mechanical energy, ie without using the otherwise customary colloid mills, high-pressure dispersion pumps or ultrasound devices.
• the dispersants of the formulas (1) to (6), and the solvent, as well as the ratios of the components have been selected as indicated, the fine distribution of the oil-phase is virtually spontaneously and can for example by simple 'shaking or stirring by means of a static mixer, or can also be brought about by means of a low-frequency vibrator.
• the aqueous phase is gradually added to the oily phase; however, the reverse can also be used.
• the aqueous phase advantageously contains a protective colloid.
• a protective colloid In the case of the intended use for the production of photographic layers, gelatin will preferably be used.
• other protective colloids primarily water-soluble high-molecular substances such as casein, water-soluble derivatives of cellulose and other high-molecular carbohydrates, alginates, polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl methyl ether or graft copolymers of gelatin with water-soluble esters of acrylic acid, methacrylic acid, maleic acid or maleic acid or maleic acid be used.
• the aqueous phase can also contain other substances required for the construction of photographic layers, such as silver halides, colloidal silver, water-soluble components such as stabilizers or hardeners, wetting agents, and finely dispersed water-insoluble polymers, such as e.g. Polyacrylic esters included;
• the oily phase can also be dispersed in water which contains part of the gelatin required for the layer structure, the dispersion thus obtained being subsequently mixed with the rest of the aqueous phase.
• the oil-in-water emulsions produced according to the invention differ from emulsions conventionally produced by mechanical means not only in terms of increased stability, but also in the particular type of particle size distribution that arises. While in conventionally produced emulsions the particle size distribution mostly follows a Gaussian normal distribution or logarithmic normal distribution, the distribution parameters of which depend largely on the mechanical means used and the energy expended, the distribution of the emulsions according to the invention which arise practically spontaneously generally follows a Poisson function and is independent of the mechanical energy expended (see W. Feller, An Introduction to Probability Theory and its Applications, Vol. I, Second Edition, page 146 ff., John Willy and Sons, New Yörk / London / Sydney). In particular, it is possible to use the method according to the invention to achieve a fine distribution with average Chen particle sizes far below one in order to produce, which could only be achieved with the conventional method with very high technical effort and correspondingly high costs.
• the usual measurement methods such as sedimentation analysis, turbidity measurement or the counting of light or electron microscopic images can be used to measure the particle size distribution.
• the occurrence of a Poisson distribution function the characteristic feature of which is the complete determination by a single parameter (in this case the average particle size or the particle volume), can serve as reliable evidence that a spontaneous emulsion produced according to the invention is present.
• mechanically produced emulsions with Gaussian or log-normal distribution require two parameters for the description of the distribution characteristics, namely the mean particle size and the standard deviation.
• Volatile solvents which are also used in the production of the oil phase, escape from the layer with the evaporating water at the latest when drying. In general, however, it will be preferred to recover the solvents before the photographic layers are made. This can be done either by partial evaporation of the oil phase before emulsification, or by partial evaporation of the oil-in-water emulsion, in which case the solvent escapes together with part of the water contained in the outer phase and after separation from the latter can be recovered. Non-volatile solvents, together with the substance dissolved therein, remain in the layer as finely divided emulsion droplets.
• the oil-soluble magenta coupler of formula (712) is used to produce three emulsion batches with different dispersant-coupler ratios, according to the following compositions:
• the coupler and the two dispersants of the formulas (120) and (411) are melted together at a temperature of 50 ° C. and then mixed together with the aqueous gelatin solution at a temperature of 40 ° C. with gentle stirring.
• the mixing of the two phases can also advantageously be carried out using a static mixer.
• a static mixer is e.g. from a cylindrical tube, in which a series of spiral deflection elements are installed, each of which is rotated by 90 ° C in short sections.
• Such mixers are suitable for homogeneous mixing of mutually miscible phases.
• an emulsion D is prepared in a conventional manner and with the following composition using the same coupler:
• the coupler is dissolved in the mixture of tricresyl phosphate and ethyl acetate, then roughly dispersed in the solution of gelatin and the surfactant in water heated to 40 ° C (e.g. using a stirrer or a static continuous mixer). This is followed by fine dispersion, e.g. in 6 passes through a high-pressure homogenizer at approx. 300 bar.
• an evaporator e.g. a thin-layer evaporator
• the ethyl acetate and part of the water are virtually completely removed from this emulsion and then the weight is adjusted to 6000 parts by weight with water.
• the particle size distribution is then determined for all 4 emulsions A to D, for example by means of turbidity measurement or by measuring and counting an electron micrograph. The following measurement results are obtained:
• Emulsion D ent prepared by conventional methods also holds almost 1.5 parts of fiber in the form of the non-volatile tricresyl phosphate on one part by weight of the coupler.
• the high-pressure homogenization and evaporation of the solvent also require very complex special equipment, which makes the conventional emulsification process not insignificantly more expensive.
• one of the other photographic additives mentioned above can also be incorporated into an aqueous emulsion.
• An emulsion analogous to Emulsion C of Example 1 is prepared by using the cyan coupler of formula (719) instead of the magenta coupler and compound (405) instead of compound (411). Average particle sizes and specific surface area of the disperse phase correspond to the values of emulsion C in Example 1.
• Emulsion C in Example 1 analog-emulsion is prepared by adding, instead of the magenta coupler to Gelbkup p ler of formula (707) and in place of Compound (411) Compound (405) was used.
• a finely dispensed emulsion with comparable values for the average particle size and specific surface is obtained in the same way.
• the components are mixed and cast at a temperature of 40 ° C on a substituted glass plate to form a thin layer.
• the layer is allowed to solidify at 10 ° C. and then dried in an air stream at room temperature.
• a strip cut to 4.0 cm x 6.5 cm is exposed under a step wedge for 2 seconds at 500 lux and then treated at 24 ° C as follows:
• a clear purple step wedge is obtained from both emulsion A according to the invention and from comparison emulsion D.
• the following maximum densities are obtained in the densitometric measurement:
• the higher dye yield and correspondingly higher maximum density of the photographic layer can be explained by the smaller volume of the coupler particles and a faster penetration of the color developer during the development of a layer which contains emulsion A.
• Example 5 a) 305 g of the yellow coupler of the formula (707) are added
• one of the dispersants of the formulas (414), (415), (416), (417) or (418) or a mixture of two or more of these dispersants can be used with equal success.
• the gelatin used in this example has an isoionic point at pH 5.1.
• Example 6 For a chromogenic black and white material, the following color coupler mixture is mixed with the dispersants mentioned by melting:
• the mixture is introduced into 5300 g of a 5% gelatin solution at 40 ° C. with gentle stirring. A finely dispersed emulsion of the coupler mixture is obtained without further mechanical processing.
• a photographic material can be produced therefrom which, after exposure, color development and fixing, provides a deep black negative image with high opacity.
• Examples 7 to 10 relate to photographic casting solutions which are prepared using the spontaneous emulsions described in the preceding examples. They can be used for the production of photographic layers for chromogenic color materials.
• Example 7 44 g of the spontaneous emulsion of the yellow coupler of the formula (707) prepared according to Example (5a) are mixed with 6.67 g of a photographic emulsion which contains 10% silver bromide and gelatin. The mixture is poured onto a polyester support in such an amount as a uniform layer that after drying a layer with 13 mg of the yellow coupler, 383 mg of silver bromide and 2500 mg of gelatin per square meter is formed.
• Example 8 44 g of the spontaneous emulsion prepared according to Example (5d) are mixed with 7.7 g of a light-sensitive emulsion which contains 6% gelatin and 10% silver bromide. The mixture is poured onto a polyester support in such an amount as a thin, even layer that after drying a layer with 382 mg of the magenta coupler, 220 mg of the light stabilizer, 442 mg of silver and 2610 mg of gelatin is formed per square meter.
• Example 9 44 g of the spontaneous emulsion prepared according to Example (5b) are mixed with 5.75 g of a light-sensitive emulsion which contains 6% gelatin and 10% silver bromide. The mixture is poured onto a polyester support in such an amount as a thin, uniform layer that after drying a layer with 444 mg of the cyano green coupler, 2480 mg of gelatin and 330 mg of silver per square meter is formed.
• Example 10 42.8 g of the spontaneous emulsion described in Example (5e) and 7.8 g of a 5% gelatin solution are mixed together. The mixture is then poured onto a polyester support in such an amount as a uniform, thin layer that, after drying, a layer is formed which contains 300 mg of the UV absorber and 2500 mg of gelatin per square meter.
• Example 11 (Comparative example)
• the emulsions described in Examples 6 to 10 are repeated in a conventional manner by dissolving the couplers and light stabilizers in tricresyl phosphate and finely dispersing them in a gelatin solution in a conventional manner using a high-pressure homogenizer.
• the comparison emulsions are mixed with a silver bromide emulsion and additional gelatin solution and poured onto a polyester support, so that after drying photographic layers with the same basis weights of gelatin and coupler or light stabilizer are obtained.
• the sensitometric tests carried out in the customary manner show that the layers obtained from the spontaneous emulsions and the respective comparison emulsions give comparable results, the spontaneous emulsions obtained according to the invention being able to be produced in a substantially simpler and cheaper manner and moreover being very stable.
• Example 12 a) 25 g of the dye of the formula (740), 120 g of the dispersant of the formula (302) and 40 g of the dispersant of the formula (418) are melted together at a slightly elevated temperature and introduced into 5000 g of a 5% gelatin solution . With gentle stirring and without further mechanical processing, a finely dispersed emulsion spontaneously formed.
• an equal amount of the dispersant of formula (303) can also be used.
• Example 13 27 g of the dye of the formula (741), 120 g of the dispersant of the formula (203), 27 g of the dispersant of the formula (418) and 50 g of methylene chloride are melted together at a slightly elevated temperature and then mixed with 5000 g of a 5% mixed gelatin solution.
• a very finely dispersed spontaneous emulsion is obtained without further mechanical processing.
• the emulsions according to Examples 12 and 13 can be mixed by mixing with silver halide emulsions and possibly other additives such as e.g. Sensitizers, plasticizers and / or gelatin hardeners produce casting solutions that can be cast in thin layers on photographic supports and dried.
• the photographic materials thus produced can be processed to light-fast color images with good color rendering by the silver color bleaching process.

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• Emulsifying, Dispersing, Foam-Producing Or Wetting Agents (AREA)

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• 1980
  • 1980-05-08 US US06/147,785 patent/US4284709A/en not_active Expired - Lifetime
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