Abstract: An adsorption process and system for the selective adsorption of a more readily adsorbable component, such as nitrogen, as from air or other feed gas mixture is carried out using a composite adsorbent bed containing different adsorbent materials positioned in separate zones in which the temperature conditions favor adsorption performance of the particular adsorbent material under applicable processing conditions in each zone. A method for the selection of the adsorbent materials is based on Adsorption Figure of Merit values.

Abstract: A system for controlling the atmosphere within a container, including a plurality of adsorption beds for the selective removal on a cyclical basis and in a predetermined order of at least part of any water vapour, ethylene, carbon dioxide and oxygen components present in the atmosphere in an adsorption phase of the cycle mechanism for controlling the flow of atmosphere within the system and mechanism for desorbing the adsorption beds in accordance with a desorption phase of the cycle.

Abstract: A multifunctional air filter module includes a filter case having an air introduction side opening and an air discharge side opening and a pleated fabric air filter element containing an activated carbon. The periphery of the pleated filter element is fixed in the filter case without clearance therebetween. At least one fabric filter element composed of a fabric including an activated carbon having a strong base, KMnO.sub.4 or ZnCl.sub.2, a fabric of a cation exchange fiber or a fabric of an anion exchange fiber, is simply placed in air introduction side grooves formed by pleats of the fixed air filter element, and is replaceable and can be regenerated. The air filter module is compact and can reduce the volume of a space occupied thereby in a semiconductor plant. Flexibility of installation thus is provided and the range of the use thereof is widened. Multifunctionality is increased easily merely by addition of replaceable filter element fabrics.

Abstract: The invention comprises a PSA gas prepurifier for the removal of contaminants present in a feed gas stream. The prepurifier of the invention has a bed of adsorbent material which comprises at least two discrete layers of adsorbents, at least one of the adsorbents being comparatively strong and at least another of the adsorbents being comparatively weak.

Abstract: An apparatus for purifying feed air by adsorption of water vapor and carbon dioxide therefrom includes a purification vessel in which are defined vertically arrange chambers and another purification vessel in which are defined vertically arranged chambers. None of the chambers is in a series flow relationship with any of the others. Each chamber contains a bed of one or more adsorbents which is able to adsorb water vapor and carbon dioxide from the feed air and which forms a reversible part of a gas flow path extending between locations external of the vessels. Valves are associated with the vessel and are operable to permit during a first adsorption period of time simultaneous flows of air to to purified through at least two of the chambers and during a second regeneration period of time simultaneous reverse flows of regeneration gas through the same chambers.

Abstract: The present invention provides a respirator filter system suitable for filtering toxic agents, including organic vapors, acid gases, formaldehyde, ammonia, and methylamine as well as pesticides, CS and CN tear gases, dusts, mists, fumes and radionuclides from environmental air to be respired by a user of the filter system. In general, the filter system of the present invention includes a cartridge containing a layer of an unimpregnated activated carbon, a layer of an activated carbon impregnated with sulfate, molybdenum and at least one impregnate selected from the group consisting of copper and zinc, and a HEPA filter. Cartridges containing these adsorbents or adsorbents similar to them (in carbon tetrachloride activity and chemistry) have been discovered to be uniquely capable of filtering a broad range of toxic agents.

Abstract: An adsorption process and system for the selective adsorption of a more readily adsorbable component, such as nitrogen, as from air or other feed gas mixture is carried out using a composite adsorbent bed containing different adsorbent materials positioned in separate zones in which the temperature conditions favor adsorption performance of the particular adsorbent material under applicable processing conditions in each zone. A method for the selection of the adsorbent materials is based on Adsorption Figure of Merit values.

Abstract: Hydrocarbon gas is separated from a gas mixture by concentration swing adsorption in a system consisting of a pair of adjacent adsorption beds that are contained in a cylindrical vessel and separated by a flat partition wall. The system is operated with the beds out of phase, such that one bed is in adsorption service while the other bed is regenerated by purging the bed with air. The pressure and temperature in the bed undergoing adsorption does not differ from the pressure and temperature, respectively in the bed being regenerated sufficiently to create significant stresses in the partition separating the beds.

Abstract: An arrangement for conducting air filtration by biofilter operation is provided. The arrangement generally includes at least one bioreactor bed, through which air to be purified is passed. Preferably the arrangement is configured so that air flow through each tank is from the top downwardly. In general, the biofiltration operation is conducted under pressures of less than ambient, to advantage.

Abstract: A process for separating components of a gas by adsorption in an enclosure (1) divided into equal tight separated compartments (27) each provided with an adsorbent material (7, 8) chosen in function of the gas to be treated and each provided for temporarily allowing the gas to be treated to be introduced and at least one chosen component of the components of this gas to be evacuated whilst the other component or components of this gas are adsorbed by the material (7, 8), which process consists in introducing the gas to be treated into one of the compartments (27) until a predetermined pressure is reached while in the next compartments (27), gas to be treated is introduced in at least one compartment (27) and the chosen component is allowed to escape, the pressure in the next compartment (27) is allowed to drop so as to obtain a partial desorption of the non chosen component or components of the gas, a purging fluid is injected in the last compartment to achieve the final desorption, and device for carrying ou

Abstract: In a pressure swing adsorption plant for the production of oxygen enriched gas a pressure vessel contains a first bed of molecular sieve adsorbent located adjacent an outlet 4 of the vessel which has an optimum operating efficiency at approximately ambient temperature and a second bed 10 of molecular sieve adsorbent which has an optimum efficiency below that of ambient operating temperature located adjacent the inlet 2.

Abstract: A pressure swing adsorption apparatus (10) is provided with actuator air via a reservoir (40) which draws its supply either from one or more of the process vessels (12) after it has been dried thereby or directly from the system compressor (32). Controls are provided to ensure actuator air is preferentially drawn from the dried source and for ensuring instrument air is available even on start up of the apparatus.

Abstract: The air purifier is used in a forced air heating and cooling system. It includes a cabinet assembly having therein a removable adsorber media carrier assembly. The carrier assembly includes a plurality of removable and refillable adsorber tubes provided with pelletized activated carbon or other adsorption media. The adsorber tubes are made from wire mesh and are arranged in rows with the air flowing through the cabinet assembly striking and impinging on the adsorber tubes in order to purify the air.

Abstract: A process and system for removing contaminants from air comprises flowing a compressed air stream comprising water and carbon dioxide to a first adsorbent zone for contacting with a first adsorbent effective in the adsorption of water by flowing the air in a direction within the first adsorbent zone parallel with the axis of the first adsorbent zone to form a dry gas; flowing the dry gas from the first vessel to a second adsorbent zone comprising a second adsorbent disposed in a radial arrangement about the same axis to remove carbon dioxide. Regeneration of the adsorbent beds may be carried out independently.

Abstract: An apparatus for removing fumigation gasses from fumigated structures is provided. Air is directed from a structure through an adsorption unit and then recirculated back into the structure. A fan directs air through the adsorption unit. The adsorption unit contains an annularly shaped adsorption bed and an inner passage way and outer passage way through which fumigation gasses are directed. A lower adsorption efficiency per pass through the adsorption bed is used in conjunction with multiple passes with the method of the present invention.

Abstract: A process and apparatus for the selective recovery of solvents from solvent gas mixtures according to which the solvent gas mixture undergoes a sorption process, individual solvent gas fractions are fractionally desorbed from the sorption agent, condensed at staggered time intervals, measured to determine their composition, and collected separately.

Abstract: The present invention is an apparatus and method for preferentially adsorbing carbon monoxide from a gas stream containing carbon monoxide in the presence of water and potentially ammonia while not adsorbing methane, hydrogen or carbon dioxide which may be present in the gas stream using an adsorbent of a supported cuprous compound situated downstream serially from a pretreatment adsorbent of 3A zeolite which protects the cuprous compound from water. An additional pretreatment layer of a basic metal compound to protect the acid-unstable 3A zeolite layer is also contemplated.

Abstract: The present invention is an apparatus and process for separating oxygen from air by adsorption of at least nitrogen on multiple layers of air separation adsorbent in an adsorption bed wherein the multiple layers are Na X-zeolite followed by at least another layer of adsorbent selected from the group consisting of Ca X-zeolite, Li X-zeolite, Ca A-zeolite followed by Ca X-zeolite, Ca A-zeolite followed by Li X-zeolite, Ca X-zeolite followed by Li X-zeolite, Li X-zeolite followed by Ca X-zeolite and Mg A-zeolite followed by Ca X-zeolite.

Abstract: In a pressure-swing adsorption-type gas separation unit, a distinct intermediate gas passageway is formed between a first water retaining bed (A) and a second separating adsorbent bed (B), a controlled heat flow being supplied to prevent the formation of a very cold area between both beds. The unit is particularly useful in the production of oxygen from air.

Abstract: An activated carbon filter is provided for venting a fuel tank. The activated carbon filter consists of a housing which accommodates activated carbon packets. Via lines, the housing is connected, on the one hand, by way of a first connection with the fuel tank, and on the other hand, by way of a second connection with the intake pipe, particularly that of a combustion engine. A third connection connects the housing with the atmosphere. The housing has a first partition which extends between the connection for the atmosphere and the connection for the tank. At least one other partition is provided which forms at least one other chamber. Each of the chambers is filled with activated carbon.

Abstract: The gas stream which emanates from landfills is treated to produce a purified gas which is essentially a hydrocarbon such as methane which can be used as the fuel source in a fuel cell power plant, or can be used in other power plants which use natural gas as a fuel. The landfill gas passes through a system which removes essentially all of the hydrogen sulfide; water; organic sulfur and halogen compounds; and solid contaminants from the gas stream. The resultant purified gas stream can be cleanly flared; used to power an energy plant; or put to other useful purposes.

Abstract: A system for controlling the atmosphere of a container for use in the storage and/or transportation of perishable goods which includes adsorption apparatus for the selective adsorption in whole or in part and in a predeterminded order of any water vapor, carbon dioxide, oxygen or ethylene contained within the atmosphere, a blower for urging the atmosphere to the adsorption apparatus, and a conduiting for returning the controlled atmosphere to the container.

Abstract: Air is purified by being passed in sequence through a first, lower, bed of activated alumina particles which adsorb water vapor preferentially therefrom, and a second, upper, bed of zeolite 13X molecular sieve particles which adsorb carbon dioxide preferentially therefrom. The air passes upwardly through the first bed and downwardly through the second bed. Once fully loaded with the adsorbent components, the beds and are regenerated by the passage therethrough of hot regeneration gas. one part of the regeneration gas flows downwardly through the first bed; another part flows upwardly through the second bed. The hot regeneration gas causes the previously adsorbed components to be desorbed. Once regeneration has ended, and the beds have returned their adsorbing temperature, they may be used again to purify air.

Abstract: A method for removing fumigation gasses from fumigated structures is provided. Air is directed from a structure through an adsorption unit and then recirculated back into the structure. A fan directs air through the adsorption unit. The adsorption unit contains an annularly shaped adsorption bed and an inner passage way and outer passage way through which fumigation gasses are directed. A lower adsorption efficiency per pass through the adsorption bed is used in conjunction with multiple passes with the method of the present invention.

Abstract: An apparatus for supplying high purity gas comprises a cylinder having a valve with two internal ports. One internal port is used to fill the cylinder while the other is fitted with a unit which removes particulates and impurities from the gas as it leaves the cylinder. The unit comprises an inlet, a first filter for removing coarse particulates, layers of adsorbent and absorbent for removing impurities, and a second filter for removing fine particulates. The purified gas leaves the cylinder via the valve and after passing through a regulator, a flow control device and various lengths of tubing passes through a conventional purifier immediately upstream of the point of use. The apparatus reduces the load on the purifier and hence decreases the frequency at which the purifier has to be recharged. Potentially the apparatus could obviate the need for the purifier altogether.

Abstract: A passive filter for taking up gaseous substances, preferably gaseous smelling substances, from a space, including a porous sorbating, self regenerating material composition, including two material components (A, B), of which a first material component (A) consists of one or more porous materials such as perlite, zeolite, bentonite, silicon dioxide ground to powder or christobalite, and a second material component (B) consists of one or more materials with the capability to take up water molecules directly from the surrounding air, such as silicon dioxide gel, starch or derivatives of cellulose, gypsom, silicates of alkali, aluminum silicate, or fuller's earth. The material components (A, B) are kept joined into a lattice by means of a binder, at which the first material component (A) join with 50-95%, preferably 80-90% (percentage of weight), and the second material component (B) with 5-50%, preferably 10-20% (percentage of weight), in the material composition.

Abstract: A ceiling fan filter for filtering the air in a room having a ceiling fan is made from at least one layer of resilient polymeric fiber filter material. Each layer has a length, a width, an upper surface, a lower surface and two side edges which extend along the length of the layer. A narrow compressed strip is formed in the filter material by compressing and heating the layer of filter material so that the filter material is fused together. The compressed strip causes an expanded thickness of the side edges to increase the effective filter surface area of the filter and gives the filter a semicircular cross-sectional shape perpendicular to the length of the filter. An adhesive layer is joined to the lower surface of the filter to attach the filter to the fan blade of a ceiling fan.

Abstract: A carbonate spring bath system includes a supplying device of a CO.sub.2 gas, a dissolving device of the CO.sub.2 gas into a bath water, and a bathtub. The supplying device of the CO.sub.2 gas comprises a combustor for obtaining a combustion gas including the CO.sub.2 gas, a CO.sub.2 adsorption tower connected to the combustor through a gas feed line and connected to the dissolving device through a supply line, a cooler for cooling the combustion gas prior to being fed to the CO.sub.2 adsorption tower and a heater for heating an adsorbent filled in the CO.sub.2 adsorption tower for desorbing the CO.sub.2 gas therefrom. The adsorbent capable of adsorbing the CO.sub.2 gas from the combustion gas at a relatively low adsorption temperature and of desorbing the CO.sub.2 gas therefrom at a relatively high desorption temperature. As the CO.sub.2 gas in the combustion gas is adsorbed in the CO.sub.2 adsorption tower in accordance with a thermal swing adsorption method, the CO.sub.

Abstract: A gas containing malodorous/harmful components is treated with an iodine- and/or inorganic iodide-supporting activated carbon honeycomb 6 disposed in a gas passageway 5 extending from a gas inlet 3 to a gas outlet 4. The gas may be treated with this iodine-and/or inorganic iodide-supporting activated honeycomb 6 and an acid-supporting activated carbon honeycomb 7. A fan 8 may be provided in a downstream position within the gas passageway. The operation of the fan may be associated with a sensor for detecting malodorous/harmful components and/or a timer which controls the operating duration of a motor. The above activated carbon honeycomb will eliminate various malodorous/harmful substances, such as ammonia and sulfur-containing compounds, with high efficiency and low flow resistance. The activated carbon honeycomb can be used for the treatment of a variety of gases and is particularly useful for the deodorization of toilets.

Abstract: A pressure swing adsorption plant for the separation of gas mixtures includes at least one pressure vessel containing an adsorbent bed that is able preferentially to adsorb at least one component of the gas mixture. The pressure vessel has an inlet at its top for the feed gas mixture, an outlet at its bottom for non-adsorbed gas and at least one heat conductive member containing a liquid medium arranged within the bed such that, in operation, heat is able to be conducted by convection through the liquid from a region of maximum temperature at or near the bottom of the bed to a region of minimum temperature at or near the top of the bed.

Abstract: A direct-positive photographic silver halide emulsion which is spectrally sensitized with a cyanine dye in which the position 2 or 4 of a 1,8-naphthyridine ring is joined through the position 2 of a thiazole ring through a methine linkage is disclosed. Said emulsion has no decreasing tendency of the maximum density and shows no color stain due to the remains of the dye. Photographic elements employing such emulsion are also disclosed.

Abstract: The present invention relates to light-sensitive photographic material with a light-sensitive heavy metal compound, e.g. a silver halide, and a spectral sensitizer. The spectral sensitizer is a compound in which the radicals of a sensitizing dyestuff are covalently bonded to amino, imino, hydroxyl, mercapto, carboxylic acid or carboxylic acid amide groups of a natural hydrophilic colloid, preferably gelatin.The invention also relates to new sensitizing dyes which are dinuclear cyanine dyes or merocyanine dyes which have attached either to a heterocyclic nucleus of the dye or to its methine chain a group which is reactive with a hydrophilic colloid.

Abstract: A spectrally sensitized silver halide photographic emulsion containing, in combination, supersensitizing amounts of at least one sensitizing dye represented by the following general formula (I): ##STR1## wherein Z.sup.1 and Z.sup.2 each represents an atomic group necessary for completing a benzimidazole nucleus, an oxazole nucleus, a benzoxazole nucleus, a naphthoxazole nucleus, a thiazole nucleus, a benzothiazole nucleus, a naphthothiazole nucleus, a selenazole nucleus, a benzoselenazole nucleus or a naphthoselenazole nucleus excepting that both of Z.sup.1 and Z.sup.2 do not simultaneously represent an atomic group necessary for completing an oxazole nucleus, a benzoxazole nucleus or a naphthoxazole nucleus; R.sup.1 and R.sup.2 each represents an aliphatic group which may be substituted and the carbon chain of which may be interrupted with an oxygen atom or a sulfur atom; R.sup.0 represents a hydrogen atom, an alkyl group or an aralkyl group; X.sub.(1).sup.

Abstract: Methine dyes comprising first and second nuclei joined by a double bond or a methine linkage. The first nuclei may be eitherA. a pyrido nucleus joined at the 4- or 6-carbon atom thereof to said double bond or methine linkage or,B. a 5,6-dihydropyrido nucleus joined at the 4- or 5-carbon atom to said double bond or methine linkage.The pyrido or dihydropyrido nucleus can have fused to its 1,2-side the atoms required to complete a ring containing 5 or 6 atoms. The second nuclei may be either the same as (a) or (b) or can be of the type typically used in cyanine styryl and merocyanine dyes. Such dyes are useful filter dyes and spectral sensitizers for silver halide compositions. Also described are intermediates useful in the synthesis of said dyes.

Abstract: A silver halide photographic emulsion containing, in supersensitizing amounts, at least one sensitizing dye represented by the following general formula (I) ##EQU1## wherein Z.sub.11 represents the atoms necessary to complete a pyridine nucleus or a quinoline nucleus; Z.sub.12 represents the atoms necessary to complete an oxazole nucleus, a benzoxazole nucleus, a naphthoxazole nucleus, an imidazole nucleus, a benzimidazole nucleus or a naphthoimidazole nucleus; and R.sub.11 and R.sub.12 each represents an aliphatic group with at least one of R.sub.11 and R.sub.12 having a carboxy or sulfo group; and at least one sensitizing dye represented by the following general formula (II) ##EQU2## wherein Z.sub.21 and Z.sub.22, which can be the same or different, each represents the atoms necessary to complete a thiazole nucleus, a benzothiazole nucleus, a selenazole nucleus or a benzoselenazole nucleus; and R.sub.21 and R.sub.22 each represents an aliphatic group with at least one of R.sub.21 and R.sub.

Abstract: A silver halide photographic emulsion containing, in supersensitizing amounts, at least one sensitizing dye represented by the following general formula (I) ##EQU1## wherein Z.sub.11 represents the atoms necessary to complete a thiazole nucleus, a selenazole nucleus, a benzothiazole nucleus, a benzoselenazole nucleus, a naphthothiazole nucleus or a naphthoselenazole nucleus; Z.sub.12 represents the atoms necessary to complete a naphthothiazole nucleus, or a naphthoselenazole nucleus; and R.sub.11 and R.sub.12 each represents an aliphatic group with at least one of R.sub.11 and R.sub.12 having a carboxy or sulfo group; and at least one sensitizing dye represented by the following general formula (II) ##EQU2## wherein Z.sub.21 represents the atoms necessary to complete a thiazole nucleus, a benzothiazole nucleus, a naphthothiazole nucleus, a selenazole nucleus, a benzoselenazole nucleus or a naphthoselenazole nucleus; Z.sub.

Abstract: A silver halide photographic emulsion containing, in supersensitizing amounts, at least one sensitizing dye represented by the following General Formula (I): ##EQU1## in which Z.sub.11 represents an atomic group necessary for completing a pyridine or quinoline nucleus; Z.sub.12 represents an atomic group necessary for completing an oxazole, benzoxazole, naphthoxazole, imidazole, benzimidazole or naphthimidazole nucleus; and R.sub.11 and R.sub.12 each represents an aliphatic group and at least one of R.sub.11 and R.sub.12 is an aliphatic group containing a carboxy group or a sulfo group; and at least one sensitizing dye represented by the following General Formula (II): ##EQU2## in which Z.sub.21 represents an atomic group necessary for completing a thiazole, benzothiazole, naphthothiazole, selenazole, benzoselenazole or naphthoselenazole nucleus; Z.sub.22 represents an atomic group necessary for completing an imidazole, benzimidazole or naphthimidazole nucleus; an R.sub.21 and R.sub.

Abstract: A silver halide photographic emulsion containing, in combination, supersensitizing amounts of at least one sensitizing dye of the following general formula (I) ##EQU1## WHEREIN Z.sub.1 and Z.sub.2 each represents an atomic group required to form a quinoline ring; R.sub.1 and R.sub.2 each represents an aliphatic group, with at least one of R.sub.1 and R.sub.2 being a hydroxyalkyl group, an alkyl group containing a carboxyl group or an alkyl group containing a sulfo group; X.sub.1 is an acid anion; and m is 1 or 2, and when m is 1 the dye forms an intramolecular salt and at least one sensitizing dye of the following general formula (II) ##EQU2## WHEREIN Z.sub.3 represents an atomic group required to form a benzimidazole ring, a benzoxazole ring or a .beta.-naphthoxazole ring; Z.sub.4 represents an atomic group required to form a benzothiazole ring, a benzoselenazole ring, a .beta.-naphthothiazole ring or a .beta.-naphthoselenazole ring; R.sub.3 and R.sub.

Abstract: A silver halide photographic emulsion containing at least one sensitizing dye represented by the formula (I) ##EQU1## wherein Z.sub.1 represents a group of atoms necessary to complete a thiazole nucleus, a benzothiazole nucleus, a benzoselenazole nucleus, a naphthothiazole nucleus or a naphthoselenazole nucleus; Z.sub.2 represents a group of atoms necessary to complete a naphthothiazole nucleus or a naphthoselenazole nucleus; and R.sub.1 and R.sub.2, which may be the same or different, each represents an aliphatic group and at least one of R.sub.1 and R.sub.2 is an aliphatic group containing a carboxyl group or a sulfo group; and at least one sensitizing dye represented by the formula (II) ##EQU2## wherein Z.sub.3 and Z.sub.4 which may be the same or different, each represents a group of atoms necessary to complete a thiazole nucleus, a benzothiazole nucleus or a benzoselenazole nucleus; and R.sub.3 and R.sub.4, which may be the same or different, each represents an aliphatic group and at least one of R.sub.

Abstract: A method for spectrally sensitizing a photographic light-sensitive emulsion, which comprises dissolving a photographic spectrally sensitizing dye having an amidinium ion auxochrome in an organic solvent containing a substantially water-free acid having a pKa not exceeding about 5, and adding this dye-containing acid-organic solvent solution to a light-sensitive emulsion.

Abstract: A silver halide photographic emulsion containing in a supersensitizing amount the combination of at least one sensitizing dye represented by the general formula (I) ##SPC1##wherein, A.sub.1, A.sub.2, A.sub.3 and A.sub.4 each represents a member selected from the group consisting of a hydrogen atom, a lower alkyl group, an alkoxy group, a halogen atom, a hydroxyl group, an aryl group, a carboxyl group, an alkoxycarbonyl group, a cyano group, a trifluoromethyl group, an amino group, an acylamide group, an acyloxyl group, an alkoxycarbonylamino group, and a carbalkoxy group; and A.sub.1 and A.sub.2 and A.sub.3 and A.sub.4 can combine to form a naphthoxazole nucleus; R.sub.o represents a hydrogen atom, a lower alkyl group or an aryl group; R.sub.1 and R.sub.2 each represents an alkyl group, provided that at least one of R.sub.1 or R.sub.2 represents a sulfoalkyl group; X.sub.

Abstract: Light-sensitive photographic emulsions are provided which feature at least one methine dye containing a 1H-imidazo[4,5-b]pyrazine nucleus.

Abstract: A silver halide photographic emulsion which contains in combination a supersensitizing amount of at least one pseudocyanine sensitizing dye and at least one oxacarbocyanine sensitizing dye.

Abstract: in a highly or superhighly sensitive color photographic material having at least one highly or superhighly light-sensitive silver halide emulsion layer containing a color-forming coupler and silver iodobromide grains color-sensitized with a dye having at least one sulfo group or carboxy group, the silver halide emulsion grains having a mean grain size of larger than about 1 micron, the occurrence of fog due to pressure stimulus is prevented effectively by the incorporation of a high-boiling organic solvent having a boiling point of higher than about 175.degree. C at normal pressure in the silver halide emulsion layer in an amount of higher than about 20% by weight of the amount of binder present in the emulsion layer.