Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C7/00—Multicolour photographic processes or agents therefor; Regeneration of such processing agents; Photosensitive materials for multicolour processes
  • G03C7/30—Colour processes using colour-coupling substances; Materials therefor; Preparing or processing such materials
  • G03C7/407—Development processes or agents therefor
  • G03C7/413—Developers
• • 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
  • G03C5/00—Photographic processes or agents therefor; Regeneration of such processing agents
  • G03C5/26—Processes using silver-salt-containing photosensitive materials or agents therefor
  • G03C5/50—Reversal development; Contact processes

Definitions

• the element 1 0 is thereafter treated to reduce the inhibiting action of the dye-formation inhibitor to permit formation of a [56] UNITE SZ; K$S :Z?TENTS colored, positive image, 3,165,407 1/!965 McCarthy 96/22 32 Drawmgs COLOR REVERSAL PROCESS AND DEVELOPER This application is a continuation-in-part of US. application Ser. No. 188,616, filed Oct. I2, I971.
• the present invention relates to photographic coior development technology, and more particularly relates to a color reversal monobath and a process for its use, and to photographic kits adapted to prepare such monobaths.
• a widely used process for reversal color development of silver halide photographic films employs a succession of baths through which exposed photographic films must be passed.
• a first bath may include a black and white developing agent which reduces silver halide in latent image areas of a film to silver, forming negative silver image therein.
• the film may be uniformly exposed to light to form fog centers in undeveloped areas of the film, and then treated with a color developer solution in which a color developing agent reduces silver halide in the fogged areas to silver, and is itself oxidized.
• the oxidation product of the developer reacts with one or more color couplers which may be distributed throughout various layers of the film to form dyes therein.
• the silver images may then be bleached from the film, and unreacted silver halide may be removed therefrom by fix ing to thus provide positive, colored images.
• a number of intermediate wash baths are commonly employed.
• a stop" bath is ordinarily utilized to halt black and white development immediately after treatment of the film in the black and white developer bath.
• the present invention in one embodiment relates to a photographic color reversal development process which comprises:
• a hydrophilic colloid e.g., gelatin
• At least one black and white developing agent having a polarographic half-wave potential at pH l0.0 of from about -lO millivolts to about l 87 millivolts, and
• a water-soluble dye-formation inhibitor which is capable of preventing said color developing agent from coupling with a color coupler, thereby to imbibe the silver halide layer with the monobath and to develop solely a negative black and white silver image therein;
• the practice of this invention includes the use of either photographic elements which contain couplers originally distributed in at least one emulsion layer or elements which contain spectrally sensitized silver halide and require the subsequent addition of color couplers as by a later bath solution.
• the element is removed from the developer bath and is fogged," e.g., by exposure thereof to light, or by treatment thereof with known chemical foggants such as hydrazine, potassium borohydride, amine boranes, etc. At this point, the element still retains imbibed therein the monobath.
• color development of the element by the imbibed color developing agent may occur in those areas of the element which were fogged after black and white developing forming a positive colored image when color couplers are present.
• the inhibiting effect of the dye-formation inhibitor may be reduced, for example, by treating the element with a composition which, for example, neutralizes or reduces the tendency of the inhibitor to form a reaction product with oxidized color developer.
• a composition which, for example, neutralizes or reduces the tendency of the inhibitor to form a reaction product with oxidized color developer For example, when sulfite is employed as a dye formation inhibitor, the element may be treated with a solution of a sulfitereactive composition to neutralize sulfite in the imbibed monobath.
• the inhibiting effect of the dye formation inhibitor may be reduced, in a preferred embodiment. by decreasing the concentration of inhibitor in the imbibed layer, as by washing the imbibed layer with a solution which is capable of dissolving the inhibitor.
• Aqueous solutions of from about pH 7 to about pH 13 are preferred for this procedure, particularly when sulfite is employed as the dyeformation inhibitor.
• Such solutions preferably include a basic ingredient such as sodium hydroxide, SO dium carbonate, trisodium phosphate dodecahydratc, etc, to render the solution alkaline, and may further include such photographic additives as sodium sulfite. fogging agents, surfactants, color couplers (particularly when a couplcnf'ree photographic element is to be developed to form a monochromatic image), etc.
• the washing solution is preferably chosen so as to be sulfitedissolving; i.e., it exhibits the capacity to remove sulfite from the imbibed monobath solution to thus per' ml! color development to occur.
• the pH of the wash bath should be high enough to convert the salt to an amine.
• the dye-formation inhibitors of this invention may operate by selective reaction with oxidized color developer to prevent them from coupling to form a colored dye.
• the inhibitors may also act upon the developing agent to prevent its oxidation so that no colored dye is formed.
• this latter inhibiting mechanism may be performed by blocking the amine group(s) on the color developing agents in the bath. The blocking may be accomplished, for example, by forming amine salts of the color developing agents (e.g., NHJCF, Nl-l CH hBri '*lNH(CHq)g Ol"l
• the particular conditions and parameters of the monobath solution depend to some degree upon the particular mechanism which is selected to inhibit the formation of dye by the coupling of developing agent and color coupler.
• the dye formation inhibitor is selected so as to form with the oxidation product of the color developing agent a reaction product which is either colorless or removable, the following characteristics in the monobath are generally preferred:
• the monobath should have a pH of about 8.5-14
• the dye-formation inhibitor should be present in sufficient quantity so that substantially all dye formation in a silver halide photographic element is restrained in said monobath after exposure of said element therein to light.
• the dye formation inhibitor acts by blocking the reactive amine group(s) of the color developing agent it may be desirable to have the pH of the bath below 8.5 and in many instances well below 7.0 (as low as 3.01.
• photographic color developing agent refers to a compound capable of reducing silver halide to silver and in turn being oxidized, the oxidation product thereof being reactive with a photographic color coupler to form a dye.
• Photographic color developing agents of the p-phenylenediamine type e.g., 2- methyl-4-lN-ethyl-N-(Banethylsulfonamidoethyl- )amino] aniline and 4-amino-N-ethyl-N-(B-hydroxyethyl)-ani1ine and their salts, are preferred.
• Such color developing agents are known to the art, and reference is made to Mees and James, Eds, The Theory ofrhe P
• Color developing agents having a polarographic half-wave potential at pH 1 1.0 of from about 159 millivolts to about 305 millivolts are par ticularly preferred.
• black and white photographic developer employed herein, reference is made to one or more black and white developing agents which are capable of reducing silver halide to silver but which are incapable of reacting, in oxidized form, with a photographic color coupler to form a dye; this term includes mixtures of black and white developing agents, for examp1e,hydroquinone and 1-phenyl 3-pyrazolidin0ne.
• Such developing agents include those known to the art such as those ofthe hydroquinone series (e.g., hydroquinone, chlorohydroquinone, broniohydroquinone, methylhydroquinone, dichlorohydroquinone, omethoxyhydroquinone and catechol), those of the p-arninophenol series (e.g., N-methyl-p-aminophenol sulfate, p-hydroxyphenylgly cin and p-aminophenoll and those of the pyrazolidinonc series, particularly 3-pyrazolidinones such as 1phenyl-3-pyrazolidinonc.
• the hydroquinone series e.g., hydroquinone, chlorohydroquinone, broniohydroquinone, methylhydroquinone, dichlorohydroquinone, omethoxyhydroquinone and catechol
• those of the p-arninophenol series e.g., N
• the black and white developing agents ofthe invention as defined above prcfera bly are further characterized by the formula wherein M is a cyclic organic nucleus (cg, benzene, pyrazolidinone) which includes no cyclic atoms other than carbon and nitrogen, Y is an OH group bonded to acyclic carbon atom of said nucleus, and X is a hydrogen atom or a hydroxyl, alkylamino, carboxyalkylamino, amino, alkyl or aryl group, X being bonded to acyclic atom of said nucleus.
• the black and White pho tographic developer of the invention includes at least one black and white developing agent having a polarographic half wave potential at pH 10.0 of from about -10 millivolts to about -l87 millivolts.
• half-wave potentials E /z
• the half-wave potential can be related to the reaction rate of the developing agents with silver halide.
• Bent et a1 Chemical Constitution, Elev trochemical, Photographic and Allergenic Properties of p-Amino-N-clialkylanilinci, J. Am. Chem.
• the Lewis and Randall Convention (G. N. Lewis and N. Randall, Therrriodynamlcs, McGraw Hill, New York, 1923, page 389) has been employed herein with respect to the values of polarographic half wave potential of black and white and color photographic developing agents.
• the polarographic half wave potentials referred to herein are oxidation potentials which may be experimentally determined by employing the method reported in Julian and Ruby. The Use ofStarionury Platinum Micmeltctrode in the Determination Qf Half Wave Potentials, J. Am. Chem. Soc. 72, 4719. 1950. the values being taken relative to the hydrogen electrode at pH 10.0 (black and white developing agents) or pH l L0 (color developing agents).
• the concentration of black and white developer in monobaths of the invention may be very low (eg. at least as low as 0.0045 moles/liter).
• the particular controls used on a system depend, of course, upon the particular materials used. Since the basic desired mechanism of the process is to have the black and white developer favorably compete with the color developer for the image silver halide certain considerations must be given in the formulation of the monobath compositions. Where the black and white developer has a significantly higher half-wave potential than the color developer, there is already a strong tendency for the black and white developer to develop the image and a relatively weak color dye formation inhibitor (either by selection of material or low concentration) may be used. When there is not a substantial dif- TAHLE 0F SCME OXIDATION PULAHOGRAPHIC C OLOR DEVELOPERS pH of Measurement;
• the parameters of half-wave potentials used in describing the useful developing agents define the limits of useful materials for each category of developing agents. That means, for example. that a black and white developer with a half-wave potential at pH ll) of less than l87 millivolts will not produce satisfactory results in this process even by exercising the known controls over the reaction mechanisms.
• the process can be performed with substantially all developing agents selected from within the half-wave potential ranges for each of the agents. The half-wave potential therefore satisfactorily generically describes the materials which can be used in this process.
• HAM -l-JAVE POTENTIALS Compound CH CH it:t+-N 279) 266.0 -222.0 N,N-dietityl-p-phenylenediamine CH UH CH3 H N-tl(ethy1) -321.5 -229.0 490.0 E-amino-S-d1ethylaminotoluene (co-2) ,Etl'tjl H N lk 4269.5 -2 '.O 490.0 4-a.m.ino-ll-etth,yl-N-( methane-sulfonamidoethyl] CH CH S0 CH mtoluidine (cu-3) 3 ,am l H N-G- N -188 .0 t-anino-E-methyl-N-ethyl-M'p Judt'oityethyl) CH CH OH aniline (ent) TABLE OF SQIB OXIDATIW POLARWRAPHIC HALF-H
• color developing agent contributes at least 40 percent up to about 95 mole percent of the total moles of developer (black and white plus color developing agents).
• the monobaths of the invention include at least 0.02 moles/liter up to the solubility limit of color developing agent in the monobaths. Preferably, from about 0.06 to 0.10 moles of color developing agent per liter is employed.
• the water-soluble, dye-formation inhibitor which is preferably employed in the present invention is a com position, such as sulfite, which is capable of reacting with oxidized color developer which may be formed during the black and white development step to form therewith a stable reaction product.
• Sulfite is preferred.
• sulfite as used herein, reference is made to sulfite and bisulfite compounds which, when dissolved in wa ter, liberate sulfite ion.
• Preferred sources of sulifte ion include ammonium sulfite and the alkali metal sulfites such as sodium sulfite, potassium sulfite, etc, particularly sodium sulfite.
• the monobath of the invention must contain sufficient dye-formation inhibitor to re strain substantially all dye formation in the silver halide photographic element in the monobath after exposure of the element in the monobath to light.
• the monobath of the invention employs inhibitor (e.g., sulfite) in a concentration of 0.10 moles/liter and more preferably from about 0.15 to about 0.48 moles/liter.
• inhibitor e.g., sulfite
• the mole ratio of sulfite/color developer be at least 0.97 and more preferably L46 to 7.8.
• suitable dyeformation inhibitors which form reactive products with oxidized color developing agents include ascorbic acid, citrazinic acid, 4-hydroxy3-butanone, etc.
• dye-formation inhibitors include hydroquinone monocarboxylic acid hydrazine.
• Dyeformation inhibitors of this type which form reaction products with oxidized color developing agents and which are useful in the invention may be selected by reference to the following simple test:
• Dye'ft'irmation inhibitors which act to prevent oxidation ofthe color developer may be chosen according to the following test:
• Any compound which when added to the monobath system reversibly reduces the oxidation potential of the color developer below that of silver is effective as an inhibitor which prevents oxidation of the color developing agent. This may readily be measured by known electrolytic cell techniques. By reversible it is meant that some alteration of condition in the bath or subsequently added material can regenerate the color developing agent from the blocked color developing agent.
• the color developing agent prior to its addition to the black and white developer. That is, it is within the scope of the invention to add the color developing agent and dyc-formation inhibitor as one compound, for example. by adding the color developing agent in its already in hibited form. This form may be for example a blocked amine salt or a complex of the color developing agent.
• the monobaths of the invention may, of course, in clude various other photographic adjuvants such as bromide ion. surfactants, color couplers, benzyl alcohol, ethylene gylc-ol, thiocyanates and the like.
• the ordinary process steps normally used in finishing the picture should be used here. That after the bath to remove the inhibiting effect. there should be an acid stop bath, then bleach bath, fix bath (or bleach/fix bath ⁇ , wash, and stabilizing bath. Hardeners may be added to any or all of the stop, bleach, fix or bleach/fix baths, or a prehardening bath may be used prior to development in the monobath. The compositions of such baths are well known in the art and need not be discussed here.
• a quick wash step has been found desirable to remove the solution retained on the surface of the photographic element so as to prevent contamination of the latter bath.
• This wash is not of sufficient length of intensity as to reduce the inhibiting effeet, but is only used to remove the solution held by surface tension on the photographic clement. Of course if one is using water as the inhibitor removing second bath such a quick wash would be unnecessary.
• the present invention relates to a color developer kit from which can be prepared positive-acting color devclopment monobaths for color development of silver halide photographic elements.
• the kit comprises a plurality of packages containing predetermined quantities of developer monobath ingredients, the kit including A. at least one photographic color developing agent capable, upon oxidation thereof, of reacting with a photographic color coupler to form a dye. B. at least one black and white developing agent haw ing a polarographic half-wave potential at pH I of from about millivolts and about l87 millivolts; and
• one package may contain an acidic solid or aqueous liquid which includes sulfite, color developing agent and black and white developer
• the second package may contain an alkaline concentrated liquid or solid which includes an alkaline substance such as sodium hydroxide, a source of bromide ion and sulfite.
• a three-package kit may have a first package which includes a concentrated, acidic solid or aqueous liquid containing a color developing agent plus sulfite, a second package which includes a concentrated acidic solid or aqueous liquid which contains the black and white photographic developer plus sulfite.
• each package containing a concentrated alkaline solid or aqueous liquid which includes a base such as sodium hydroxide, a source of bromide ion, and sulfite.
• a base such as sodium hydroxide, a source of bromide ion, and sulfite.
• each package be made as concentrated practicable.
• the contents of each package may be desirable in some instances to provide certain of the package contents in the form of aqueous dispersions, thereby enabling high concentrations of ingredients to be achieved and further promoting easy dissolution of the dispersed ingredients when the working monobath is prepared. It may be desirable to some instances to provide the monobath ingredients in solid, preferably powdered form.
• each package of the kits of the present invention is carefully premeasured so that the monobaths of the invention may be prepared by adding the entire contents of each package sequentially to water, and diluting to a predetermined volumev
• sufficient basic material e.g., sodium hydroxide
• sufficient dye formation-inhibitor must be provided so that the resulting monobath does not permit dye formation to occur during black and white development therein of a photographic element. etc.
• tag, from developer kits, color developing agent solubility problems are largely avoided by first forming an aqueous solution of color developing agent, and thereafter adding the alkaline ingredients thereto.
• EXAMPLE 1 A gelatino silver halide photographic film containing red, green, and blue-sensitive layers (the layers containing appropriate color couplers dispersed therein by a solvent dispersion technique) was exposed through a grey wedge (continuous, logarithmic density wedge) in S a scnsitometer and was developed for 3 minutes at 70F. in total darkness in a monobath of the following composition:
• the film carrying imbibed monobath was 20 placed in an aqueous solution containing 40 g. per liter of sodium carbonate. and was exposed therein to light for 3 minutes. The film was then washed with water, bleached for 2 minutes in a bleaching bath consisting of Water 900 ml. Potassium ferrieyanide 75 g. Potassium bromide l5 g.
• Example I was repeated exactly except that the aqueous sodium carbonate solution was replaced with distilled water. Similar results were obtained.
• EXAMPLE 3 A silver halide photographic element similar to that employed in Example was exposed through a grey wedge to light and then developed for 5 minutes at F in total darkness in a developer monobath of the following composition:
• EXAMPLE 4 A silver halide photographic element similar to that employed in Example 1 was exposed to light through a grey wedge and then developed for 5 minutes at 70F. in total darkness in a developer monobath of the following composition:
• Example 1 was duplicated exactly with similar photographic material except that, in the monobath. 9.0 g. of p-hydroxyphenylgylcin was substituted for hydroquinone. The following densitometric properties were obtained:
• EXAMPLE 6 A photographic silver halide color reversal film similar to that employed in Example 1 was exposed through a grey wedge in a sensitometer and was then developed for 3 minutes at 70F. in total darkness with agitation in a developer monobath of the following composition:
• EXAMPLE 7 A color reversal silver halide photographic film similar to that of Example 6 was exposed to a light image and then developed for 4 minutes at F. in total darkness in a developer monobath of the following composition:
• Example 1 for 2 minutes, also in total darkness. and was then further washed. bleached. fixed, washed and dried in accordance with Example I.
• the film was thereafter immersed in a second bath of the following composition and re-exposed therein to room light illumination for 3 minutes:
• EXAMPLE 13 A kit for preparing a monobath of the invention was formulated as follows into two packages:
• the contents of package A are dissolved in 700 ml. of water, and the contents of package B are dissolved in 200 ml. of water.
• the resulting solutions are then combined and diluted to 1000 ml. to provide a working monobath solution of the invention.
• EXAMPLE 14 This example illustrates the inhibiting mechanism whereby oxidation of the color developer is prevented by blocking the developer.
• test strip of this material was exposed on an EK l 01 sensitometer for 2 seconds before a logarithmic step wedge.
• This strip was processed in the development formulation described in this example for 4 minutes at F in total darkness.
• the test strip was removed from the development bath and placed in a bath containing 40.0 g/l of Na CO for 3 minutes while being exposed to room light illumination. During this time, dye formation was noted to take place.
• the test strip was subjected to conventional ferricyanide bleach, wash, stop-fix, wash and stabilization steps; any step of which does not impose any limitations on this invention. This treatment resulted in the production of a color positive image of the following densitometric characteristics:
• the sulfite concentration in this example is such as could be sufficient to act as an inhibitor by forming a reaction product with oxidized color developing agent
• the pH of this bath is such that there can be no oxidation of the color developer.
• the sulfite is present only as a stabilizer and does not here inhibit coupling of oxidized color developer, as there is none until the pH is raised.
• a bath for photographic positive color development of silver halide photographic elements comprising, in aqueous solution at a pH of from 8.5 to 14:
• said at least one color developing agent has a polaro graphic half-wave potential at pH l l.0 of from about -l59 millivolts to about 305 millivolts.
• the dye formation inhibitor is selected from the group consisting of sulfite, ascorbic acid, citrazinic acid, 4-hydroxy-3-butanone and hydroquinone monocarboxylic acid hydrazides.
• a color developer bath for positive color development of silver halide photographic elements comprising, in aqueous solution of pH 85-14,
• black and white photographic developer includes hydroquinone and l-phenyl-3-pyrazolidinone.
• a photographic color reversal development pro cess which comprises A. treating a color photographic element having a hydrophilic colloid silver halide layer bearing a latent image with an aqueous bath solution which in cludes at least 0.02 moles/liter of photographic color developing agent capable, upon oxidation, of reacting with a photographic Color coupler to form a dye, black and white photographic developer including at least one black and white developing agent having a polarographic half-wave potential at pH 10.0 of from about l0 millivolts to about l87 millivolts, and water-soluble dye-formation inhibitor in a concentration ofat least 0.10 moles/- liter, said concentration being sufficient so that substantially all dye formation of a silver halide photographic element is restrained in said bath after said element has been exposed to the light.
• the mole ratio ofinhibitor to color developer being at least about 0.97. thereby to imbibe said silver halide layer with said bath solution and to develop solely a negative black and white image therein;
• said fogging step comprises exposing said film bearing said black and white silver image to light.
• said fogging step comprises treating said film bearing said black and white silver image with a fogging agent.
• a photographic color reversal development process which comprises A. treating a photographic element having a hydrophilic colloid silver halide layer bearing a latent image with an aqueous alkaline bath which includes at least 0.02 moles/liter of primary aromatic amine color developing agent capable, upon oxida tion thereof, of reacting with a photographic coupler to form a dye, said color developing agent having a polarographic half-wave potential at pH 1 1.0 of from about l 59 to about 305 millivolts, black and white photographic developer which includes hydroquinone, and from 0.10 to 0.48 moles/liter of inhibitor in a concentration sufficient so that substantially all dye formation of a silver halide photographic element is restrained in said bath after said element has been exposed to light, the mole ratio of inhibitor to color developer being at least about 0.97, thereby to imbibe said bath into said silver halide layer and to develop solely a negative black and white silver image therein;
• a color developer bath for photographic positive color development of silver halide photographic elements comprising, in aqueous solution of pH 85-14.
• a black and white photographic developer including at least one black and white developing agent having a polarographic half-wave potential at pH 10.0 of from about l millivolts to about l87 millivolts;
• a water-soluble, dye-formation inhibitor in a concentration of at least about 0.10 moles/liter which is capable of reacting with the oxidation product of said color developing agent to form a stable, soluble complex and which is present in sufficient quantity so that substantially all dye formation of a silver halide photographic element is restrained in said bath after exposure of said element to light, the mole ratio ofinhibitor to color developer being at least about 0.97.
• a photographic color reversal development process which comprises A. treating a photographic element having a hydrophilic colloid silver halide layer bearing a latent image with an aqueous alkaline bath which includes at least 0.02 moles/liter of photographic color developing agent capable, upon oxidation of reacting with a photographic color coupler to form a dye, black and white photographic developer including at least one black and white developing agent having a polarographic half-wave potential at pH 10.0 of from about l0 millivolts to about l87 millivolts, and water-soluble dye-formation inhibitor in a concentration sufficient so that substantially all dye formation of a silver halide photographic element is restrained in said bath after said element has been exposed to light, and of at least about 0.10 moles/liter, the mole ratio of inhibitor to color developer being at least about 0.97, thereby to imbibe said silver halide layer with said bath and to develop solely a negative black and white silver image therein;
• a bath for photographic positive color development of silver halide photographic elements comprising in aqueous solution at a pH of from 8.51 4;
• said color developing agent having a polarographic half-wave potential at pH 1 1.0 of from about l 59 to about 305 millivolts,
• the dye formation inhibitor is selected from the group consisting of sulfite, ascorbic acid, citrazinic acid, 4-hydroxy-3-butanone and hydroquinone monocarboxylic acid hydrazides.
• a bath for photographic positive color development of silver halide photographic elements comprising in aqueous solution at a pH of from 8.5l41
• the dye formation inhibitor is selected from the group consisting of sulfite, ascorbic acid, citrazinic acid 4-hydroxy-3-butanone, and monocarboxylic acid hydrazides.

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• 1972
  • 1972-08-14 US US280263A patent/US3883354A/en not_active Expired - Lifetime
  • 1972-10-02 NL NL7213318A patent/NL7213318A/xx unknown
  • 1972-10-02 SE SE7212705A patent/SE388489B/xx unknown
  • 1972-10-10 CA CA153,598A patent/CA979705A/en not_active Expired
  • 1972-10-11 FR FR7235912A patent/FR2156227B1/fr not_active Expired
  • 1972-10-11 AR AR244599A patent/AR194851A1/es active
  • 1972-10-11 JP JP47101831A patent/JPS5143379B2/ja not_active Expired
  • 1972-10-11 DD DD166160A patent/DD99676A5/xx unknown
  • 1972-10-11 IT IT7253312A patent/IT972366B/it active
  • 1972-10-11 IL IL40549A patent/IL40549A/xx unknown
  • 1972-10-11 AU AU47639/72A patent/AU460085B2/en not_active Expired
  • 1972-10-11 DE DE2264986*A patent/DE2264986A1/de active Pending
  • 1972-10-11 GB GB4697972A patent/GB1403408A/en not_active Expired
  • 1972-10-11 CH CH1481572A patent/CH581337A5/xx not_active IP Right Cessation

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