Abstract: A method for delivering at least two working gases from a common air supply comprising the steps of depleting the air in O2 in order to obtain a first gas mixture having an O2 content less than or equal to t1; delivering at least a portion of this first gas mixture as a first working gas; depleting another portion of this first gas mixture in O2 in order to obtain the second gas mixture having an O2 content less than or equal to t2, wherein t1 is greater than t2; and delivering the second gas mixture as a second working gas.

Abstract: A fuel storage system is provided including a storage tank, an exhaust port, a filter system, a primary pump, and at least one secondary pump. The storage tank includes a fuel delivery port, a fluid vent port, and a pollutant return port. The filter system includes a filter input port coupled to the fluid vent port, a fuel vapor duct, and primary and secondary filter output ports. The fuel vapor duct defines a flow path extending from the filter input port to the primary filter output port. The primary filter output port is coupled to the pollutant return port. At least a portion of the fuel vapor duct forms a permeable partition designed to pass a non-pollutant component of fluid within the fuel vapor duct through the permeable partition and designed to inhibit passage of a pollutant component of fluid within the fuel vapor duct through the partition. The secondary filter output port is partitioned from the fuel vapor duct by the air-permeable partition and is coupled to the exhaust port.

Abstract: The invention relates to a device for supplying a purified gas to a plant which is purged with purified gas. The device includes a feed line connected, on the one hand, to a source of substantially pure gas and, on the other hand, to an inlet of the plant. The purified gas being passed therethrough is contaminated with impurities. The device further includes a line which is intended to recover the contaminated gas at the outlet of the plant and is connected to the feed line. The lines are arranged one after the other downstream of where the recovery line is connected to the feed line, a compressor and a device for separating the impurities from the contaminated gas by permeation in order to supply a purified gas to the plant.

Abstract: A gas recovery device utilizes membranes of a gas permeable, liquid impermeable substance to strip gas from gas-containing liquids, such as brine in subterranean geological formations. The device includes a shell defined by perforated outer walls and a plurality of elongated permeation tubes. Only one end of the tubes is attached to a plenum with the tube lumina in fluid communication with the plenum. The remainder of the tubes is not anchored and therefore is free to move. Substantially liquid-free gas is removed from the plenum through a pipe to a remote facility for storage and use. The gas recovery device can be deployed within the casing of a well suspended by the product discharge pipe and immersed in gas-containing brine flowing from a natural geological formation. The brine seeps into the well casing and flows through the perforations to surround the permeation tubes.

Abstract: An object of the present invention is to provide a method for recovering a gas using a semipermeable membrane in an apparatus having a simple structure. The method is capable of maintaining a purity of a product gas at a constant value even if a feed amount of a feed stream is fluctuated. A feed stream G1 is a gas mixture of a fast gas having a relatively high permeability to a membrane 1 and a slow gas having a relatively low permeability to the membrane 1. The feed stream G1 is pressurized by a compressor 3 and fed to a membrane 1 separation unit 2 having the membrane 1. Part G7 of the permeate stream on the permeate side of the membrane 1 is recirculated to the upstream side of the compressor 3 through the first recirculation line 17 and merged into a stream of the feed stream G1. Simultaneously, another part of the permeate stream G2 on the permeate side of the membrane 1 is recovered through a product gas recovering line 5.

Abstract: A gas-separation membrane enables the economical separation of noble gases, especially xenon, from oxygen, nitrogen, carbon dioxide or mixtures of the latter gases. The membrane of the present invention includes a thin discriminating layer selected from the group consisting of polycarbonate, polyester, and polyestercarbonate. In the preferred embodiment, the thin discriminating layer includes material selected from the bisphenolic group consisting of 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane, 2,2-bis(3,5-dichloro-4-hydroxyphenyl)propane, and 9,9-bis(3,5-dibromo-4-hydroxyphenyl)fluorene. The invention also includes the method of using the membrane, made as described above, either in a single-stage process or in a multiple-stage process, to provide the desired product gas. Several membrane units, made according to the present invention, may be manifolded together so as to operate in a parallel fashion, to provide an increased volume of product gas at the same desired purity.

Abstract: A gas separation membrane device comprising an internally staged permeator containing a three dimensional array of hollow fiber membranes grouped into multiple sets in intimate contact with each other is described. The incorporation of the internally staged permeator, particularly, the arrangement of the multiple sets of fiber membranes in intimate contact with each other, results in improved efficiency of the device, especially for feed streams or membrane types that lead to high permeate flow rate that result in excessive shellside pressure drops.

Abstract: A process for reducing pollutants, particularly nitrogen oxides from combustion gases during a combustion process that takes place while oxygen is supplied, includes providing oxygen needed for the combustion process by separating oxygen from a gas mixture containing oxygen and nitrogen in a two-step process including (a) enriching the gas mixture with oxygen in a first step to provide an enriched gas mixture; and (b) separating oxygen out of the enriched gas mixture in a second step, wherein, during at least one step oxygen depleted gas mixture is removed via an outlet provided with permeability means that cause the outlet to have a higher permeability for nitrogen than oxygen.

Abstract: A process for separating natural gas and carbon dioxide from a raw feed stream, such as in carbon dioxide for EOR processes. Separation is by membrane separation at low pressures. By utilizing low pressure separation, highly selective membranes can be used and recycling becomes practical.

Abstract: The present invention is a fundamental method and apparatus of a microcomponent assembly that overcomes the inherent limitations of state of the art chemical separations. The fundamental element enabling miniaturization is the porous contactor contained within a microcomponent assembly for mass transfer of a working compound from a first medium to a second medium. The porous contactor has a thickness, and a plurality of pores extending through the thickness. The pores are of a geometry cooperating with a boundary tension of one or the other or both of the media thereby preventing migration of one, other or both through the microporous contactor while permitting passage of the working compound. In the microcomponent assembly, the porous contactor is placed between a first laminate such that a first space or first microplenum is formed between the microporous contactor and the first laminate. Additionally, a cover sheet provides a second space or second plenum between the porous contactor and the cover sheet.

Abstract: This disclosure features a permeation storage chamber in a tube having a first membrane delivering a permeate flow into an intermediate chamber. This chamber delivers flow from a second membrane. The intermediate chamber delivers surplus permeate out through a pressure regulator, or a drain tube. Pressure stabilization at the second membrane enables constant permeation discharge, avoiding pressure or temperature dependent flow rate charges.

Abstract: A system for controlling the atmosphere in the container comprising a membrane separation apparatus to separate nitrogen and a second separation apparatus, adapted to separate carbon dioxide and water vapor from a gas mixture in the container. The separated nitrogen is returned to the container, as is at least a portion of the carbon dioxide and water vapor, so as to produce and/or maintain a pre-determined atmosphere composition within the container thereby to prevent spoilage of perishable products within the container.

Abstract: A dehumidifying device in which lower humidity can be achieved in a side to be dehumidified (a side of a box) and the stable continued effect can also be obtained without any dehumidifying effect which stays at a low level due to water vapor gas electrified by an electric panel accommodated in the box side, hydrogen gas existing in outside air, or other floating dusts easily electrified in the air or the like. The dehumidifying device comprises a tubular body provided in a wall section of a box and forming a vent path for air communication between inside and outside of the box, and a vent body formed by providing an electrically grounded conductive porous body adjacent to at least one side of a waterproof membrane having moisture-permeable micro-throughholes to make a pair therewith and arranging at least two pairs thereof at a space from each other inside said tubular body to shield an inside space of the vent path into at least one chamber in the direction from the box to the outside.

Abstract: A fuel storage system is provided including at least one storage tank, an air exhaust port, a first filter assembly, a primary pump, a least one secondary pump, at least one additional filter assembly, and an additional secondary pump. The first filter assembly includes a filter input port, a fuel vapor duct, a primary filter output port, and a secondary filter output port. The filter input port is coupled to a fluid vent port. The fuel vapor duct defines a substantially unobstructed flow path extending from the filter input port to a primary filter output port. The primary filter output port is coupled to a pollutant return port. The secondary filter output port is partitioned from the fuel vapor duct by an air-permeable partition. The primary pump is positioned to cause fluid to pass from the filter input port to the primary filter output port.

Abstract: A process train for treating a gas stream containing methane, nitrogen, and at least one of water vapor, acid gas, C.sub.3+ hydrocarbons and aromatic hydrocarbons, the gas stream typically, but not necessarily, being natural gas. The treatment train includes separation of methane from nitrogen by means of membranes that preferentially permeate methane and reject nitrogen. Preferred processes include both a dehydration step and an NGL removal step to treat the gas before it passes to the methane/nitrogen membrane separation step. The process train can also include additional steps, such as an acid gas removal step, or a cryogenic methane/nitrogen separation step.

Abstract: An oxygen generating device (11, 211) to which a gas mixture containing oxygen is fed, and which is operable to separate the gas mixture into oxygen rich and oxygen depleted gas components, the device (11, 211) including a negative temperature coefficient material (36a 36b 36c; 236) which is active at an elevated temperature above a minimum operating temperature, to separate the gas mixture into oxygen rich and oxygen depleted gas components, there being an electronic control unit coupled to the device to pass an electrical current through the device (11, 211) to produce a heating effect within the device to heat the gas mixture at least towards the minimum operating temperature wherein the device includes a plurality of active sections (A, B, C) through each of which the gas mixture passes in turn, and the electrical current supply is connected to each of the sections (A, B, C) so that the sections electrically are connected in series.

Abstract: The present invention relates to a porous monolithic support (1) for filtration membranes containing channels (2, 3, 4), the internal surface of which supports the membranes (14, 15, 16), characterized in that the said support contains at least two channels, all of said channels having:(a) substantially similar sections,(b) interchannel partitions (5, 6, 7) and partitions with the outside of the support (8, 9, 10) of substantially constant thickness and(c) a partition with the outside of the support of substantially the same surface area.Application to the tangential filtration of viscous fluids and/or of fluids containing solid materials.

Abstract: A membrane process and apparatus are described for the production of a desired very high purity permeate gas by use of a multiple stage membrane process wherein in a primary stage a process feed gas mixture is provided to a primary membrane separator unit comprising a membrane having a relatively high intrinsic permeability to provide an intermediate permeate gas and a retentate gas, and providing the intermediate permeate gas in a secondary stage to a secondary membrane separator unit comprising a membrane having a relatively low intrinsic permeability, to produce therefrom a very high purity permeate gas product.

Abstract: The invention relates to an inorganic filter element comprising:a rigid inorganic porous support; andchannels classifiable into n categories where n.gtoreq.2, with all of the channels in each category having identical right cross-section, identical hydraulic diameter, and identical equivalent diameter, the shapes of the right cross-sections of the channels differing between categories.According to the invention, the channels of the various categories have:hydraulic diameters such that the ratios between any two hydraulic diameters lie in the range 0.75 to 1.3;right cross-sectional areas such that the ratios between any two right cross-sectional areas lie in the range 0.75 to 1.3; andequivalent diameters such that the ratio of the equivalent diameter over the hydraulic diameter of each channel is less than or equal to 2.

Abstract: A separation module uses a series of separation elements with interconnecting hardware that greatly reduces the time necessary for assembly of interconnected elements and the machining or preparation of an extended part of the module inside diameter for acceptance of the elements. The elements use an interconnection between the modules that provides a sliding seal for first engaging adjacent modules and allowing alignment while a secondary seal is brought into contact and locked to provide a rigid axial attachment between the separation elements. The module arrangement further uses a single outer seal near the end of the module into which the separation elements are inserted to reduce the amount of machining, honing, or sleeving necessary to seal the module against by-passing of feed or impermeable components.

Abstract: An air separation system and method for producing a plurality of oxygen product streams at varying pressures and purities. The system combines a VPSA oxygen generator with a multi-stage cascade membrane unit to provide a high pressure, low purity product stream and a low pressure, high purity product stream.

Abstract: An integral coalescer filter-membrane device to provide clean sample gas to gas analyzers. The device includes a housing, an inlet port for feed gas, an outlet port to withdraw clean sample gas essentially free of entrained liquids, such as water, and particulate material which might contaminate or interfere with the gas analyzer, a bypass port and a drain port to remove by gravity coalesced liquid. The device includes a filter tube to coalesce and filter the feed gas stream and a chamber having a supported hydrophobic selected porosity membrane. The outlet port receives clean sample gas from the upper portions of the chamber, while the bypass port removes coalesced filtered gas from a lower chamber.

Abstract: An installation for detecting the presence of helium in a fluid circuit, the installation including a tapping member constituting a volume comprising a first internal space and a second internal space separated from each other by a semi-permeable partition through which helium can pass, the first space of said tapping member being inserted in series in the fluid circuit, the second space being connected both to a gas source via an orifice having an adjustable aperture, and also to a pumping member via a pipe, the flow pumped through the pipe conveying the flow under viscous conditions towards a feed member connected to a helium leak detector.

Abstract: Membrane separation methods and systems separate gaseous mixtures into purified component gases thereof. Purified oxygen gas (60-90% purity), for example, may be derived from ambient air in an efficient manner. Systems and methods are provided by which at least three permeator stages are used while requiring less than one compressor per stage. Energy requirements are reduced and product purity as a function of energy requirements is improved.

Abstract: The invention relates to an inorganic element for filtering a fluid medium, in order to recover a filtrate. According to the invention, the inorganic filter element includes:radial partitions of constant thickness over their entire height, with a ratio of partition height over partition thickness being not greater than 8; andconnection fillets of radius lying in the range 0.3 mm to 1.5 mm.

Abstract: The membrane deaerator according to the present invention includes a plurality of membrane deaerator modules and a water sealed vacuum pump connected thereto. These modules are series-connected between a raw water supply line and a deaeration water supply line. A first vacuum pump is connected to a first deaerator module via a deaeration line, and a second vacuum pump is connected to a second deaerator module via the deaeration line. These vacuum pumps are each provided with a seal water supply line which is used to send the raw water introduced from the water supply line thereinto as seal water to each of the first and second vacuum pumps. A discharge line for the second vacuum pump is connected to the deaeration line for the first vacuum pump. In the membrane deaerator thus formed, the deaeration performance is improved greatly, and a deaeration with dissolved oxygen concentration of several PPB can be carried out.

Abstract: A device for filtering and separating a flow medium by reverse osmosis, microfiltration, ultrafiltration or nanofiltration has a pressure-tight housing with an inlet for the flow medium and a first outlet for the retentate and a second outlet for the permeate. A plurality of stacked units comprised of spacer elements and membrane filter elements is provided. The spacer elements and the membrane filter elements are stacked alternatingly atop one another to form a stack. The stacked units further comprise two receptacle parts forming a receptacle for enclosing a stack of spacer elements and membrane filter elements. The stacked units are positioned adjacent to one another in the housing. The flow medium flows in sequence through the stacked units.

Abstract: Process and apparatus for the separation of at least one gas from an entering gaseous mixture (1), of the type in which a membrane separation is conducted with at least two successive membrane separators in the following manner: the entering mixture is passed through a first membrane separator (2) operating at a first operating temperature and all or a portion of the residual mixture (5) from this first membrane separator is passed through a second membrane separator (3) operating at a second operating temperature. A mixture enriched in the gas is obtained from the permeate outlet (6, 4) of each of these two separators. Two separators are used whose selectivities for the gas are different. These may be membranes of different type, or membranes of the same type, if the first operating temperature is different from the second operating temperature.

Abstract: High-purity oxygen is recovered from air by a high-temperature ion transport membrane system comprising two or more stages in which each stage operates at a different feed side to permeate side pressure ratio. Operation of the system in multiple stages at controlled pressure ratios produces oxygen at a lower specific power consumption compared with single-stage operation.

Abstract: The present invention relates to processes and apparatuses for starting up and shutting down membrane gas separation systems comprising at least one gas separation membrane module and at least one membrane dryer module.

Abstract: A nitrogen generator for producing nitrogen gas from air having a plurality of stages of membrane units each containing a plurality of hollow fiber membranes having a feed input at least one of the plurality of membrane units containing a sweep input to inject a sweep gas longitudinally on the external surface of the hollow fiber membranes, the generator further containing:a) a conduit for collecting a non-permeate stream of a membrane stage N and using the same as a feed stream for a membrane stage N+1;b) a conduit for collecting only a permeate stream from at least the membrane stage N, and feeding all of the permeate stream from the membrane stage N to a sweep input of at least one previous membrane stage, such that the sweep gas is injected longitudinally and counter-current to the non-permeate gas on the external surface of the hollow fiber membranes, and that the sweep gas is mixed with the gas permeating through the hollow fiber membranes to make the permeate stream; andc) a conduit for collecting a pe

Abstract: Multi-stage membrane systems are arranged so that, with the same number of modules and compressors, mixing losses upon combining recycle and feed streams are minimized. Membrane surface area and power requirements are reduced thereby.

Abstract: This invention relates to a method of and apparatus for separating component gases in a gas mixture employing a glassy polymer membrane at temperatures of 5.degree. C. or less so as to achieve superior separation of gas components.

Abstract: A process and system for pressurizing a vessel for integrity testing with gas comprising helium, recovering the gas comprising helium, and purifying the gas comprising helium for reuse. The process for purifying the gas stream comprising helium comprises drying the gas stream; separating the dried gas stream in a membrane separator stage into a helium-enriched permeate product stream and a helium-depleted raffinate stream; recovering helium in the raffinate stream in a membrane stripper stage thereby producing a purge stream; and purging water from the dryer with the purge stream.

Abstract: The apparatus includes two permeators mounted in series, namely a simple permeator with an inlet and two outlets, and a reflux permeator. The production gas results from the combination of the two permeated products. Application to the production of impure hydrogen.

Abstract: The invention relates to the control of multistage fluid separation processes and systems. The processes and systems employ at least one recycle compressor or pump in conjunction with their associated controlling system to separate a fluid mixture in an efficient manner during off demand or turndown conditions. The operation of at least one recycle compressor or pump is controlled so as to maintain the pressure in the permeate side or sides at a set value, thus maintaining the desired pressure ratio across the multistage membrane and obtain the desired, reduced power consumption during off demand or turn-down conditions.

Abstract: A membrane separation process and system for removing a component from a fluid stream. An auxiliary membrane module or set of modules is installed across the second stage of a two-stage membrane separation system. The driving force for the auxiliary modules is provided by the pump or other driving unit for the first membrane stage. The auxiliary module or modules provides additional treatment of the residue stream from the second membrane stage, but are driven by the first stage driving unit. The invention is particularly useful in any membrane separation operation involving gas separation, vapor separation or pervaporation in which a two-stage system design is to be used, and where it is desirable to improve the efficiency of the two-stage system.

Abstract: A membrane separation process and system for removing a component from a fluid stream. An auxiliary membrane module or set of modules is installed across the pump that drives the main membrane unit, so that the permeate streams from the main and auxiliary membrane units are mixed and pass together through a common driving pump. The concentration of the mixed permeate stream is allowed to build up by circulating the stream through the auxiliary unit. When the concentration has reached a desired level, the mixed stream can be tapped and the product stream drawn off.

Abstract: A color photographic material having on a support at least a photographic emulsion containing an excellent colored coupler represented by the general formula ##STR1## wherein R.sub.1 represents an aryl group or a heterocyclic group; R.sub.2 represents a phenyl group having a halogen atom, an alkoxy group, or an aryloxy group at the ortho-position to the imino group bonded to the 3-position of the pyrazolone ring of the coupler; and R.sub.3 represents a phenyl group having a hydroxyl group at the para-position to the azo group of the coupler; the coupler having a hydrophobic diffusion-resisting group in the molecule thereof.

Abstract: Suitable masking compounds for masking the undesired color side densities of image dyes produced from color couplers are those of the following formula ##STR1## in which R.sup.1 represents hydrogen or one or more substituents such as halogen, alkyl, aryl, a heterocyclic group alkoxy, hydroxyl, amino, acylamino, sulfo, sulfonyl, carboxyl or carbamyl or condensed carbocyclic or heterocyclic ring.R.sup.2 represents alkyl, aryl, a heterocyclic group carboxyl or esters or amide derived from carboxylX represents a dye group optionally containing a solubilizing group.On development with black-and-white or color-forming developers the dye group is released imagewise and is removed by aqueous processing baths leaving back a positive color or masking image.

Abstract: Color photographic elements containing silver halide and incorporated colored and color-forming materials are described. These elements have (a) a layer containing a yellow dye or yellow dye precursor that is bleachable by a mild silver-dye-bleach procedure and (b) at least one other layer, spectrally sensitized to green light, which contains a color-forming coupler which forms magenta dye upon reaction with oxidized color developer. Such elements, when they are processed by a process have improved graininess and yield sharper images. The novel process comprises the steps:A. develop in black and white developer,B. apply non-fixing silver-dye-bleach solution,C. rinse,D. fog and color developE. washF. bleach and fix.A "positive" colored image results.

Abstract: In a multilayer color photographic material essentially comprising a support having coated thereon, in succession, a red-sensitive silver halide emulsion layer and a green-sensitive silver halide emulsion layer, with an optional yellow filter layer and a blue-sensitive silver halide emulsion layer, by disposing a non-sensitive auxiliary layer containing a non-diffusible colored coupling compound which releases a diffusible dye at color development capable of being removed from the photographic layer at development, an effective masking can be applied to the side absorption of cyan dye image without reducing the sensitivity of the red-sensitive silver halide emulsion layer during storage before or after exposure.

Abstract: A novel two-equivalent naphthol or phenol type cyan coupler is disclosed wherein the active position thereof has a split-off group which contains a bonding group of the formula ##STR1## wherein R is hydrogen atom or a divalent organic group. The present coupler is incorporated into a photographic material containing a photosensitive emulsion layer.

Abstract: A coloured magenta coupler for photography is disclosed which is represented by the following general formula: ##STR1## wherein R is substituted phenyl, R.sub.1 and R.sub.2 individually stand for hydrogen, halogen, hydroxyl, alkyl, alkoxy or acylamino, with the proviso that one of R.sub.1 and R.sub.2 is hydroxyl but that both are not hydroxyl simultaneously, R.sub.3 is hydrogen, halogen, alkyl, nitro or acylamino and R.sub.4 stands for hydrogen, halogen or a monovalent organic residue.

Abstract: A color photographic material comprising a support having photographic layers thereon, with at least one of the photographic layers containing a non-diffusible colored coupler which releases, on coupling reaction with the oxidation product of a primary aromatic amino developing agent at development, a diffusible dye capable of being removed from the photographic layer, the non-diffusible colored coupler being represented by general formula (I):a--o--so.sub.2 --r--b (i)wherein R represents an alkylene group having 1 to 10 carbon atoms; A represents an image forming coupler residue containing a phenol nucleus or a naphthol nucleus, and wherein the --O--SO.sub.2 --R--B group is bonded to the coupling position of the coupler residue and the group can be released upon oxidative coupling with an aromatic primary amine developing agent to form a dye; and B represents a residue containing a chromophore.

Abstract: A diffusible-dye releasing type dye consisting of a radical which reacts with an oxidation product of a color developing principal agent in a color development process to yield a substantially colorless compound and a dye residue carrying water-soluble radicals. Its photographic uses are also disclosed.

Abstract: A method of producing a colored image by developing a latent silver image obtained by the image-wise photo-exposure of a photosensitive silver halide material, wherein the development is carried out with p-phenylenediamine corresponding to the following general formula: ##STR1## wherein: EACH OF R'.sub.1, R'.sub.2, R'.sub.3, and R'.sub.4 (same or different) represents an alkyl group, in the presence of1. a hydrazone compound having the following general formula: ##STR2## wherein: N IS 1, 2, OR 3,R.sub.1 is hydrogen or an acyl group, andR.sub.2 is a --CONH.sub.2 group or a --SO.sub.2 X group, wherein X represents a hydroxyl group, an amino group, an aliphatic group, an aryl group or an heterocyclic group,R.sub.3 is an alkyl group or an aryl group, andZ represents the necessary atoms to close a nitrogen-containing heterocyclic nucleus, and2. a color coupler of the phenol, naphthol, or active methylene compound series.

Abstract: Photographic elements containing at least one silver halide emulsion layer in which there is incorporated a cyan-color forming material which, upon reaction with oxidized color developer, forms a cyan dye having unwanted absorption in the green and blue regions of the visible spectrum can be color corrected to a surprising degree by the incorporation into said element of a colored coupler compound having the structure: ##STR1## wherein R.sup.2 is an alkyl group containing 1 to 6 carbon atoms, R.sup.3 and R.sup.4 are independently selected and are alkyl groups containing 2 to 6 carbon atoms, B is hydrogen or CooR.sup.6 wherein R.sup.6 is an alkyl group containing 1 to 8 carbon atoms, and A is a sulfonated naphthylazo group selected from those having the structure: ##STR2## wherein R.sup.5 is an alkyl group containing 1 to 4 carbon atoms, M is photographically inactive, M is a monovalent cation.

Abstract: A color photographic light-sensitive material, comprising a support having thereon at least one silver halide emulsion and the light sensitive material containing a colored cyan coupler having a main absorption in the blue region of the spectrum and a colored cyan coupler having a main absorption in the green region of the spectrum, and a colorless cyan coupler, each coupler being capable of coupling with an oxidation product of a p-phenylenediamine color-developing agent to form a cyan dye.

Abstract: This invention relates to a color photographic material with at least one silver halide emulsion layer having improved stability against crystallization and which contains in dispersed form a open chain keto methylene coupler a naphtholic or pyrazolone color coupler substituted with a 2-cyclo-pentyl-4-t-butyl-phenoxy group in a non-coupling position.