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
  • G03C7/04—Additive processes using colour screens; Materials therefor; Preparing or processing such materials
  • G03C7/06—Manufacture of colour screens
  • G03C7/10—Manufacture of colour screens with regular areas of colour, e.g. bands, lines, dots
  • G03C7/12—Manufacture of colour screens with regular areas of colour, e.g. bands, lines, dots by photo-exposure

Definitions

• This invention relates to a photographic material suitable for use in the production of a multicolour filter array element, to such element and a multicolour liquid crystal display device incorporating such element.
• Liquid crystal display devices are used nowadays in numerous applications such as clocks, household appliances, electronic calculators, audio equipment, etc.. There is a growing tendency to replace cathode ray tubes by liquid crystal display devices being favoured for their smaller volume and lower power consumption. In some applications like e.g. laptop computers and pocket TV's liquid crystal display devices are even without competition.
• High definition television in its ultimate version will require screen diagonals exceeding 50 inch (see P. Plezhko in the periodical Information Display September 1991, Vol. 7 no. 9, p. 19 a.f.) Although not yet in existence CRT-based 50 inch screens can be expected to be very impractical because of their weight and size. Liquid crystal technology is basically able to produce high definition television (HDTV) screens with moderate weight and size.
• Liquid crystal display devices generally include two spaced glass panels, which define a sealed cavity, which is filled with a liquid crystal material.
• the glass plates are covered with a transparent electrode layer which may be patterned in such a way that a mosaic of picture elements (pixels) is created.
• Two addressing systems are used to drive the display : either a passive (also called intrinsic) system or an active (also called extrinsic) system.
• the two electrode layers are patterned in a regular array of stripes.
• the stripes on one plate are perpendicular to those on the other plate.
• each pixel has its own individual microelectronic switch, which means that such a microswitch is connected to an individual transparent pixel electrode, the planar size of which defines the size of the pixel.
• the microswitches are individually addressable and are three-terminal or two-terminal switching elements.
• Two-or-more-terminal switches are formed by thin film transistors (TFT). These transistors are arrayed in a matrix pattern on a glass plate which together with a glass plate carrying a transparent uniform (non-patterned) electrode layer forms a gap filled with the liquid crystal material.
• TFT thin film transistors
• the transparent electrode layer must be patterned.
• a colour filter array element is provided on one of the two glass plates.
• this is usually the glass plate opposite the glass plate carrying the switching elements.
• a colour filter array for full colour reproduction consists of red, green and blue patches arranged in a given order.
• the colour patches may be separated by a black contour line pattern delineating the individual colour pixels as e.g. given in US-A 4,987,043.
• the colour filter is preferably kept out of the electrical circuit which means that the transparent electrode is deposited on top of the colour filter array element.
• a first widely used technique operates according to the principles of photolithography as e.g. in EP-A 0 138 459 and is based on photohardening of polymers e.g. gelatin.
• Dichromated gelatin, doped with a photosensitiser is coated on glass, exposed through a mask, developed to harden the gelatin in the exposed areas and washed to remove the unexposed gelatin. The remaining gelatin is dyed in one of the desired colours.
• a new gelatin layer is coated on the dyed relief image, exposed, developed, washed and dyed in the next colour, and so on.
• wash-off and dying technique four complete operation cycles are needed to obtain a red, green and blue colour filter array having the colour patches delineated with a black contour line.
• dyeable or coloured photopolymers are used for producing superposed coloured photoresists. In the repeated exposures a great registration accuracy is required in order to obtain colour filter patches matching the pixel-electrodes.
• organic dyes or pigments are applied by evaporation under reduced pressure (vacuum evaporation) to form a coloured patttern in correspondence with photoresist openings [ref. Proceedings of the SID, vol. 25/4, p. 281-285, (1984)].
• a mechanical precision stencil screen has been used for patternwise deposition by evaporation of dyes onto a selected substrate as illustrated e.g. in Japan Display 86, p. 320-322.
• dyes are electrodeposited on patterned transparent electrodes from a dispersion of curable binder polymers, dispersing agents and coloured pigments. For each colour a separate deposition and curing step is needed.
• red, green and blue dyes are deposited by thermal transfer from a dye donor element to a dye-receiving element, comprising a transparent support e.g. glass plate, having thereon a dye-receiving layer.
• Image-wise heating is preferably done by means of a laser or a high intensity light flash. For each colour a separate dye transfer step must be carried out.
• a method of producing a multicolour optical filter comprises the steps of
• the manufacturing yields i.e. the percentage of the colour filter array elements made in the factory which meet quality control standards, are exceptionally low.
• the very costly investments could be brought down when the filter production could be simplified and yet high quality maintained.
• EP-A 0 396 824 relates to a process for the production of a multicolour liquid crystal display device comprising a liquid crystal layer essentially consisting of nematic crystals in twisted or supertwisted configuration or smectic C (chiral smectic) ferroelectric liquid crystals wherein the liquid crystal molecules are aligned in such a way that said layer shows an electrically controllable rotation of the polarisation plane of the light incident on the display.
• Said liquid crystal layer together with a multicolour filter element is arranged between front and rear transparent electrodes for altering pixelwise the electric field over the liquid crystal layer and said electrodes are associated respectively with a front and rear light polariser element.
• Said process comprises in consecutive order the steps of:
• the uppermost emulsion layer of the thus processed photographic print material is coated with a hydrophobic water-impermeable organic resin to form a covering layer of said resin thereon, and by vacuum-deposition on top of the thus-applied resin coating a transparent electrically conducting (electrode) layer is formed.
• Said resin layer on top of the colour filter array provides a good planarity and prevents the release of volatile substances from the emulsion layer during vacuum-deposition e.g. by sputtering, of the transparent conducting layer. Usually a bake at 150 °C or even higher is needed to impart by curing a good impermeability to the resin layer.
• liquid crystal displays of the so-called twisted nematic (TN) type (as are the majority of active matrix liquid crystal displays) the transparent uniformly applied electrode and also the patterned electrode are covered with an alignment layer.
• This layer usually consists of a heat-cured polyimide resin. Rubbing this cured layer with e.g. a nylon cloth as e.g. in GB-A 1,505,192 in a given direction causes an orientation of the liquid crystal molecules near the surface of the layer in the rubbing direction.
• the multicolour filter array element is subjected to rather severe heat treatment steps during the manufacture of the liquid crystal display element. These heating steps may not give rise to discolouration of the filter and dye fading.
• R 1 , R 2 , R 3 each independently represents a substituted or unsubstituted alkylgroup or a substituted or unsubstituted arylgroup, or R 1 and R 2 or R 3 and R 2 or R 3 and R 1 or R 3 and R 7 or R 3 and R 5 or (R 1 or R 2 ) and R 5 or (R 1 or R 2 ) and R 7 together with the atoms to which they are attached represent the necessary atoms to form a ring system, R 4 , R 5 , R 6 and R 7 each independently represents hydrogen, alkyl, aryl, halogen, nitro, cyano, alkoxy, aryloxy, alkyl
• both R 1 and R 2 are lower alkyl groups, having between 1 and 6 C-atoms, more preferably C 1 to C 3 - alkyl groups, and in a further preferred embodiment R 4 , R 5 and R 7 are hydrogen, and each of R 1 , R 2 , R 3 and R 6 is either a methyl or an ethyl group.
• the cyan dyes remain the most susceptible to break down under thermal constraints, and that therefore it can be expected that thermal stability of the colour filter as a whole can be much improved by the choice of the cyan dye forming coupler.
• a further requirement is the need for dimensional stability of the colour filters coated on a transparant support which is, to a great extend, dependent on the support on which the colour filters are coated and on the presence of certain (polymeric) compounds added to the layers, especially to the subbing layer coated thereon.
• Said dimensional stability is required as the colour filters are passing the whole manufacturing cycle, including the "baking” or “heating” cycle, as the said colour filters are present in the interior of the LCD device. It is thus required that the transparent supports shouldn't be shrinking during that procedure, nor in one, nor in two dimensions, that they should withstand treatments with etchants and that their optical transparency and optical isotropy or approximate isotropy should be retained.
• the objects of the present invention are realised by providing a method for manufacturing a multicolour filter array element, firmly associated with a transparent electrode layer in a multicolour liquid crystal display device, comprising the steps of:
• a silver halide colour photographic print material comprising as a support an optically transparent and isotropic or approximately isotropic support which is characterised by a ratio of the elasticity modulus, measured in a perpendicular and in a parallel direction, of less than 1.3, said support being dimensionally stable in that the shrinkage after heat-treatment for 1 hour at 200°C is less than 5 %; and a plurality of spectrally sensitive silver halide emulsion layers coated thereupon, each of which are sensitive to a different region of the visible wavelength spectrum, wherein a red-sensitive emulsion layer comprises at least one cyan dye image forming coupler present as an oilformer dispersion, wherein said cyan dye image forming coupler corresponding to the general formula (I), defined hereinbefore, is present in an oilformer dispersion.
• print material is meant a silver halide colour photographic material that is comparable to the colour print film used in the motion picture film industry.
• the multilayer arrangement of hydrophilic colloid (gelatin containing) layers of the present multicolour print material must stick very firmly to the dimensionally stable substrate.
• glass is used as a substrate e.g. borax glass, borosilicate glass, lime glass, potash glass, soda glass, crown glass, flint glass, silica-flint glass, chromium glass, zinc-crown glass or quartz glass and the glass support has e.g.
• said glass support having further a failure stress (under tensile stress) equal to or higher than 1 x 10 7 Pa and an elasticity modulus (Young's modulus) being equal to or lower than 10 x 10 10 Pa as has been set forth in EP-Application No. 94203517, filed December 5, 1994.
• subbing layers currently used in colour print film on a resin support depends on the nature of the support. So in the case of glass supports, the said subbing layers cannot be used due to the very different nature of the glass substrates. In that case a strong adhesion of the hydrophilic colloid multilayer arrangement to the glass support can be realised by means of a very thin subbing layer containing gelatin, a water-soluble inorganic silicon compound like e.g. sodium silicate (water glass) and a gelatin hardening agent.
• an equally strong adhesion can be obtained without a subbing layer by the addition to the first layer, which in a preferred embodiment is a gelatin-containing light-absorbing anti-halation layer, of an organic silicon compound such as an epoxysilane and a hardening agent for gelatin.
• the first layer which in a preferred embodiment is a gelatin-containing light-absorbing anti-halation layer, of an organic silicon compound such as an epoxysilane and a hardening agent for gelatin.
• Liquid crystal polyester supports which are particularly suitable for use in the method according to this invention include isotropic transparent thermoplastic resins as e.g. polyethylene-terephtalate, a polyethylene naphthalate or a polyether sulphon support and especially those described in US-A's 5,385,704; 5,188,930; 5,108,666 and 5,270,160 and in EP-A's 0 619 516 and 0 651 287.
• isotropic transparent thermoplastic resins as e.g. polyethylene-terephtalate, a polyethylene naphthalate or a polyether sulphon support and especially those described in US-A's 5,385,704; 5,188,930; 5,108,666 and 5,270,160 and in EP-A's 0 619 516 and 0 651 287.
• especially preferred isotropic transparent supports, resistant to dimensional change at elevated temperatures are those comprising linear condensation polymers which have a glass transition temperature above 190°C, and more preferably above 220°C, such as polycarbonates, polycarboxylic esters, polyamides, polysulfonamides, polyethers, polyimides and the like and copolymers thereof as disclosed in US-A's 3,634,089; 3,772,405; 3,725,070 and 3,793,249 and 5,407,791 and EP-A 0 583 787.
• linear condensation polymers which have a glass transition temperature above 190°C, and more preferably above 220°C, such as polycarbonates, polycarboxylic esters, polyamides, polysulfonamides, polyethers, polyimides and the like and copolymers thereof as disclosed in US-A's 3,634,089; 3,772,405; 3,725,070 and 3,793,249 and 5,407,791 and EP-A 0 5
• shrinkage at 200°C for 1 hour in all dimensions is less than 5 %, more preferably less than 1.5 % and still more preferably less than 1 %.
• "Normal supports" have a shrinkage of about 5-10 %.
• An example of a polyethylene terephthalate film having a width to shrink by 2 to 20 % is given in EP-A 0 639 792.
• the said film should be thermofixed at a very high temperature (e.g. 240 °C) during a short period (e.g. about 10 s), followed by subjecting to a relaxation treatment as has been described in Research Disclosure 34458, December 1992.
• isotropic or approximately isotropic is understood that the ratio of the elasticity modulus, measured in a perpendicular and in a parallel direction, should approximately be 1.0, and more specifically remain less than 1.3. For polyether sulphon, this value is approximately 1.0.
• subbing layers in order to improve the dimensional stability of the support, subbing layers, optionally improving antistatic properties, are used as disclosed in e.g. US-A's 5,232,825; 5,019,494; 4,990,434; 4,977,071; 4,965,180; 5,204,219; 5,194,347; 4,994,353; 4,954,430; 5,061,611 and EP-A's 0 529 697 and 0 466 124.
• Suitable additives for improving the dimensional stability of the photographic element coated thereon are i.a. dispersions of a water-soluble or hardly soluble synthetic polymer e.g.
• the said supports are resistant to dimensional change at elevated temperatures of 100°C for at least 1000 hours, of 150°C for about 10 hours and even for more elevated temperatures of 180-200°C for about 1-2 hours.
• a temperature of 210°C should not be exceeded. It is clear that the required stability at those high temperatures during more than 1 hour is not corresponding to the one demanded from classical photographic, and, in particular, from classical silver halide colour materials.
• cyan-forming dyes corresponding to the general formula (I) representing a 2,5-diacylaminophenol-type colour coupler are preferred, wherein:
• Preferred examples of withdrawing atoms are halogen atoms, wherein F is the most preferred. Otherwise the most preferred electron withdrawing group is -CN.
• dibutylphthalate and tricresylphosphate are especially preferred, more preferably in amounts by weight from 0.3 % to 30 % versus the amount of dye image forming couplers.
• Molar amounts of oilformer and dye are from 0.2 to 5 mmole/m 2 . It should be noted that those oilformers are used in the preparation of oilformer dispersions wherein the suitable cyan image forming couplers are dispersed. This is opposite to the presence as a coating ingredient of oilformers as described e.g. in EP-A 0 380 223, wherein dye image forming couplers are not present in the colour forming layers of the colour filter material but in the developers.
• magenta dye forming couplers especially pyrazolotriazole compounds are preferred, represented, e.g., by M-1 as a more preferred example.
• benzoylacetanilide compounds are useful as yellow dye image forming couplers.
• the said compounds are disclosed e.g. in US-A 4,777,123.
• Particularly preferred benzoylacetanilide compounds are those with purine or theophylline derivatives in the coupling position.
• the sequence wherein the different spectrally sensitive silver halide emulsion layers are applied on a glass support is the sequence that is described in EP-A 0 615 161, which is incorporated herein by reference.
• the amount of colour coupler needed to obtain an optical density not higher than 2.5 at the maximum of spectral absorption of the dye formed can be determined by simple tests.
• each colour coupler containing layer is adjusted preferably in such a way that in the strongest exposed regions the colour coupler is completely converted to dye during the colour development.
• the molar equivalent ratio of silver halide to colour coupler in the print material should preferably be at least 10 % higher than 1.
• a ratio of 1 in equivalent amounts means that for each mole of colour coupler present in the layer 4 or 2 moles of silver halide are added, depending on whether the colour coupler is of the 4- or the 2-equivalent type.
• scavenging agents for that purpose are diffusion-resistant hydroquinone derivatives, preferably containing one or more aliphatic ballast groups having at least 6 carbon atoms. Such scavenging agents and their use are described e.g. in DE-A 3 545 611.
• the silver halide emulsion layer may contain any type of light-sensitive silver halide emulsion e.g. an emulsion that forms a latent image primarily on the surfaces of the silver halide grains, or that forms an internal latent image predominantly in the interior of the silver halide grains.
• the emulsions can be negative-working emulsions e.g. surface-sensitive emulsions or unfogged internal latent image-forming emulsions, or positive-working emulsions e.g. direct-positive emulsions of the unfogged, internal latent image-forming type, the development of which is conducted with uniform light exposure or in the presence of a nucleating agent.
• Direct-positive emulsions of the pre-fogged type wherein during image-wise exposure chlorine, bromine and/or iodine is liberated which image-wise destroys the developable centres created during overall prefogging.
• Direct-positive emulsions need only one development as do negative emulsions.
• Reversal silver halide emulsions are not prefogged. Their processing includes 2 development steps and a fogging step.
• the first development is carried out with a black-and-white developer whereby a negative black-and-white silver image is formed.
• the remaining silver halide is made developable by fogging, either physically (by exposure to light) or chemically.
• bleaching and fixing a positive colour image is obtained.
• negative-working is meant that the density observed after processing is proportional to the exposure.
• positive-working is meant that the silver halide emulsions yield upon exposure and development positive images i.e. the density is inversely proportional to the exposure.
• the applied silver halide can be of the silver chloride, the silver chlorobromide, the silver bromide, the silver bromoiodide or the silver chlorobromoiodide type.
• the silver halide can be surface sensitised.
• Noble metal e.g. gold, middle chalcogen e.g. sulfur, selenium or tellurium, and reduction sensitisers, employed individually or in combination, are specifically contemplated.
• Typical chemical sensitisers are listed in Research Disclosure (RD) December 1989, item 308119, section III and in RD September 1994, item 36544, section IV.
• the silver halide can be spectrally sensitised with dyes from a variety of classes, including the polymethine dye class, which includes the cyanines, merocyanines, complex cyanines and merocyanines (i.e. tri-, tetra-, and polynuclear cyanines and merocyanines) oxonols, hemioxonols, styryls, merostyryls, and streptocyanines; see said Research Disclosures 308119, section IV and 36544, section V.
• the polymethine dye class which includes the cyanines, merocyanines, complex cyanines and merocyanines (i.e. tri-, tetra-, and polynuclear cyanines and merocyanines) oxonols, hemioxonols, styryls, merostyryls, and streptocyanines; see said Research Disclosures 308119,
• Suitable vehicles for the emulsion layers and other layers of the print material are described in RD 308119, section IX, and RD 36544, section II, of said Research Disclosure. Brighteners and anti-foggants are described in RD 308119, sections V and VI, and in RD 36544, sections VI and VII respectively. Hardeners for gelatin have been described in RD 308119, section X.
• colour filters for liquid cristal displays normally comprise a repeating pattern of coloured patches as in a mosaic pattern or may form a pattern of stripes.
• the coloured patches are preferably separated by a black contour line, which, according to the present invention, is formed by superposed area of the different emulsion layers wherein on colour-development cyan, magenta and yellow dye is formed respectively.
• the reflections from the glass plate back into the multilayer arrangement are eliminated by the presence of a light-absorbing (anti-halation) layer between the glass substrate and the first photographic silver halide emulsion layer.
• This anti-halation layer must loose its light-absorbing properties during or after processing and become as clear as possible.
• one or more dyes are present in said layer which dyes should be destroyed chemically in one or more processing liquids or simply be soluble in one or more of the processing liquids or in the rinse water and be washed out.
• anti-halation dyes of the non-diffusing type i.e. dyes that are insoluble in water and do not migrate to adjacent layers during manufacture. This is important when the dyes, due to their spectral or other properties, can change the photographic properties of the adjacent silver halide emulsion layers.
• Yellow dyes of the non-diffusing type that may serve in decolourisable anti-halation layers for use in a multicolour print material according to the present invention are described in US-A 4,770,984.
• Filter or anti-halation dyes may be present in one or more layers of the multilayer arrangement to decrease unwanted interlayer reflections and/or to improve the optical characteristics of individual layers. This practice is well known to those skilled in the art as e.g. from US-A 4,770,984 or EP-A 0 582 000.
• the pixelwise exposure of the multicolour print material according to the present invention can be performed in several ways.
• the exposure may proceed in a single step through a multicolour master, in a plurality of steps with light of different colour (blue, green and red) through a pitchwise shiftable black-and-white mask or simultaneously or subsequently by means of pixelwise modulated laser beams of different colour, blue, green and red.
• a multicolour master in a plurality of steps with light of different colour (blue, green and red) through a pitchwise shiftable black-and-white mask or simultaneously or subsequently by means of pixelwise modulated laser beams of different colour, blue, green and red.
• a convenient method for manufacturing the colour filters for use according to the present invention, especially in mass-production when a great number of them is needed, is to carry out the exposure in a single step through a multicolour master.
• the master When used in conjunction with a negative type multilayer silver halide colour material the master must be a coloured negative master, whereas a coloured positive master is needed when a direct positive or reversal type multilayer silver halide colour material is involved.
• a coloured negative master has predominantly yellow-, magenta- and cyan coloured pixels at the places corresponding respectively with the blue, green and red pixels on the colour filter array element.
• the coloured master is in close or near contact with the multilayer silver halide colour material from which a colour filter should be made, the gelatin layers of both materials facing each other.
• the single step exposure simultaneously latent images in the 3 light-sensitive differently spectrally sensitive silver halide emulsion layers are formed.
• Deviation from the desired spectral transmission characteristics of the filter area may be corrected by inserting in the white light beam filters changing the proportion of red, green and blue transmitted by the multicolour master.
• the negative and positive masters may be made by means of other recording materials than silver halide emulsion type materials.
• the multicolour master may be made by photolithography, vacuum-deposition or electrodeposition of dyes, thermal transfer of dyes, electro(photo)graphy with coloured toner or inkjet printing with coloured inks.
• the developer solution comprising a p-phenylene diamine derivative corresponds to the one disclosed in EP-A No. 95200306, filed February 8, 1995, which is incorporated herein by reference and which is used in accordance with the present invention to develop a print material that is used to form a multicolour filter array useful in the production of multicolour Liquid Crystal Displays, (multicolour LCD's).
• the silver halide colour filter After processing the silver halide colour filter is covered with a protective resin layer which in the production of a multicolour filter associated with an electrode layer should be present.
• gelatin is a hydrophilic polymer it contains still a small amount of water even after thorough drying. Minor quantities of water may not enter the liquid crystal cell since they profoundly disturb the operation of the liquid cristal display. Moreover, during the application of the electrode layer by vacuum-deposition water or other volatile substance may not escape from the gelatin-containing layers and has to be kept blocked by a protective impermeable resin layer on top of the uppermost colour-developed silver halide emulsion layer of the colour filter. In the manufacture of a liquid crystal display according to the present invention heat-curable resins are used for producing said impermeable layer.
• the water-impermeable hydrophobic organic resin layer may be coated from a liquid composition containing (an) evaporatable solvent(s) or may be applied onto the processed multicolour material by lamination using e.g. a heat-curable layer sandwiched originally between a polyethylene film and a protective cover sheet analogously to the type of material described in J. Photogr. Sci., 18 , 150 (1970).
• a transparent conductive layer forming the electrode layer is applied to the impermeable resin layer by known techniques e.g. a transparent indium tinoxyde (ITO) layer is applied by vacuum-deposition.
• ITO transparent indium tinoxyde
• the multicolour filter array elements prepared according to the present invention are very well suited for the production of active matrix liquid crystal displays their use is not restricted to that type of displays. They can be incorporated likewise in passive matrix liquid cristal displays, especially in supertwisted nematic (STN), double supertwisted nematic (DSTN), retardation film supertwisted nematic (RFSTN), in ferroelectric (FLC), guest host (GH), polymerdispersed (PF), polymer network (PN) liquid crystal displays, and so on. They can further be incorporated in emissive displays like electroluminescent displays, CRT devices and in charge coupled device (CCD) cameras.
• STN supertwisted nematic
• DSTN double supertwisted nematic
• RFSTN retardation film supertwisted nematic
• FLC ferroelectric
• GH guest host
• PF polymerdispersed
• PN polymer network
• emissive displays like electroluminescent displays, CRT devices and in charge coupled device (CCD) cameras.
• Said polyester support was a colourless longitudinally and transversally stretched polyethylene terephtalate film support subbed on one side with a coating solution at a coverage of 130 m 2 per litre. The film was then heat-set while being kept under tension at a temperature of 220°C for about 10 seconds.
• Shrinkage after treatment of 1 hour at 200°C was 0.6 % in the lenght-direction and 1.2 % in the width-direction so that it can be concluded that the average shrinkage lays between 0.5 and 1 %.
• a non-diffusing yellow dye of formula YD was dispersed in gelatin.
• the coverages of yellow dye YD and gelatin were 0.5 and 1.5 g/m 2 respectively.
• a 100 % silver chloride emulsion with an average grain size of 0.4 ⁇ m was sensitised to blue light with a spectral sensitising agent of formula SB.
• a yellow dye forming coupler of formula Yl was added to this emulsion.
• the amounts of silver halide, gelatin and colour coupler Yl were 0.57, 3.30 and 1.0 g/m 2 respectively.
• a substance of formula SD capable of scavenging oxidised colour developing agent was dispersed in gelatin and coated at a coverage of 0.08 g SD/m 2 and of 0.77 g gelatin/m 2 .
• the amounts of silver halide, gelatin and colour coupler M-1 were 0.71, 2.8 and 0.53 g/m 2 respectively.
• This layer has the same composition as the first intermediate layer.
• a silver chloride-bromide (90/10 molar ratio) emulsion with an average grain size of 0.12 ⁇ m was sensitised to red light with a spectral sensitising agent of formula SR.
• a cyan dye forming coupler of formula C-1 was added to this emulsion for the material MATL1.
• MATL2 MATL3, MATL4 and MATL5 compounds of the formulae C-2, C-3, C-4 and C-5, used as comparative cyan dye forming were added.
• Amounts of silver halide, gelatin and colour coupler were 0.49, 4.5 and 0.95 g/m 2 respectively.
• C-1 to C-3 and C-5 are two-equivalent couplers, whereas C-4 is a four-equivalent coupler.
• Yellow, magenta and cyan water-soluble dyes, acting as accutance dyes were present at an appropriate coverage in the blue, green en red sensitive layer respectively and hydroxytrichlorotriazine acting as hardening agent was present in the red sensitive layer at a coverage of 0.035 g/m 2 .
• Silver halide to colour coupler ratios in equivalent amounts were about 1.2 for the three light-sensitive layers of the material.
• the coverages of the blue, the green and the red couplers, expressed in mmoles/m 2 were 1.4, 0.9 and 1.1 respectively.
• the sheets of material were developed in the developer comprising as developing compound 4-amino-3-methyl-N-ethy-N-isopropylaniline hydrochloride as developing compound, the composition of the developer being given hereinafter.
• the sheet material was treated in an acidic stop bath prepared by adding water up to 1 l to a volume of 50 ml of sulphuric acid 7 N.
• aqueous solution having the following composition : 58 % aqueous solution of (NH 4 ) 2 S 2 O 3 100 ml sodium sulphite (anhydrous) 2.5 g sodium-hydrogen sulphite (anhydrous) 10.3 g water up to 1000 ml
• each sheet was treated with the fixing liquid again and rinsed for 3 minutes with plain water.
• each sheet was treated with an aqueous solution having a pH of 9 and containing per liter 20 ml of a 40 % aqueous solution of formaldehyde serving as hardening agent.
• Example 2 Materials having the same composition were coated as in Example 1, except for the cyan dye forming coupler used in the red-sensitive layer. So for the material MATL6 compound C-1 was added to this emulsion, but the cyan dye forming coupler was dispersed together with dibutylphthalate (DBP) as an oilformer in an amount of 10% by weight. For the materials MATL7, MATL8 and MATL9 cyan dye forming couplers of the formulae C-6, C-7 and C-8 were added, wherein each of the dispersions of the cyan dye forming couplers were also containing dibutylphthalate as an oilformer in an amount of 10 wt%.
• DBP dibutylphthalate
• the cyan dye image forming couplers C-6, C-7 and C-8 all have F-atoms in their chemical structures as shown hereinafter, which, according to the results shown in Table 1 should be favourable for heat stability.
• MATL10 indicated as “comparative” differs from MATL6 in that no oilformer is used in the dispersion of compound C-1.
• C-6, C-7 and C-8 have F as electron-withdrawing atom.
• C-6 is a 4-equivalent and C-7 and C-8 are 2-equivalent couplers.
• Example 2 The sheets coated onto the same support as in Example 1 were submitted to a heat treatment at 200°C during 60 minutes in the same way as in Example 1.
• Example 3 the influence of the nature of the oilformer on the heat stability of cyan dye forming coupler C-1 was studied.
• the following oilformers were used in making a dispersion of C-1: oilformer 0-12 being dibutylphtalate (dispersion of C-1 coated in MATL11, coated as described in Example 1); oilformer O-12 (MATL12); oilformer O-13 tricresylphosphate (MATL13); O-14 (MATL14); and O-15 (MATL15).
• the formulae of the corresponding oilformers O-12 to O-15 are given hereinafter.
• MATL10 was used as a comparative (no oilformer present).
• Example 2 The sheets were submitted to a heat treatment at 200°C during 60 minutes just as in Example 1.
• Example 4 the influence of the nature of the developer on the loss in density after the heat stability test of the cyan dye image forming coupler C-1 was studied. Therefore the same materials as in Example 3 were developed in a developer comprising as developing compound 4-amino-3-methyl-N,N-diethylaniline hydrochloride instead of 4-amino-3-methyl-N-ethyl-N-isopropylaniline hydrochloride as developing compound, the composition of the developer being given hereinafter.
• the sheets were submitted to a heat treatment at 200°C during 60 minutes just as in Example 1.
• the so-called "suntest” consists in exposure during 100 hours of developed material with light of a low pressure Xenon lamp NXe 1500, manufactured by HERAEUS, filtered with a L393-filter.
• the illuminance realised with the said Xenon lamp was 110 kLux; the integral irradiance was 414.5 W/m 2 (without filter in the wavelength region between 300 and 830 nm).

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• 1996
  • 1996-07-11 DE DE1996602234 patent/DE69602234T2/de not_active Expired - Fee Related
  • 1996-07-11 EP EP19960201957 patent/EP0754974B1/de not_active Expired - Lifetime
  • 1996-07-18 JP JP20917196A patent/JPH09211813A/ja active Pending

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