Patented Oct. 8, 1946 2,409,107 UNHTED vSTTES PATENT OFFICE 2,409,107 PROCESSING OF CERTAIN NONGELATIN EMULSIONS - John I. Crabtree and George T. Eaton, Rochester, N. Y., assignors to Eastman ' Kodak Company, Rochester, N. Y., a corporation of New Jersey . ‘No Drawing. " Application October 16, 1942, . . v > Serial No. 462,233 4 Claims. .. - 1 p - (01. 95_ss) ’ ' 2 a , . Organic thiocyanates such as vthiocyanocat This invention relates to improved procedure for the processing of photographic elements ‘which include an emulsion layer of apolyvinyl inorganic thiocyanates. Examples of the most geséin which is not readily permeable to processing satisfactory thiocyanates which wehave tried echol may be employed but we prefer to use 5 are sodium, potassium and ammonium thiocy It is known to substitute polyvinyl resins for anate.‘ The thiocyanate can be added to, any a hs. ’ 1 2 the gelatin in photographic emulsions. Poly vinyl acetals such as polyvinyl acetaldehyde 'acetal, polyvinyl propionaldehyde aceta1 and polyvinyl butyraldehyde acetal; polyvinyl esters such as partially hydrolized polyvinyl acetate and mixed polyvinyl acetal-esters are examples of polyvinyl resins which have been used for this purpose. See, for instance, Fordyce 2,211,323, photographic processing bath utilized to treat the photographic element, containing the vinyl resin as above speci?ed. m Thus it can be added to the conventional developing or ?xing bath. On the other hand, it canbe used as a ?xing agent per se. and in such case a conventional ?xing vagent is unnecessary. ~ As indicated 'above our invention is applicable Aug. 13. 1940; Lowe 2,253.078, Aug. 19, 1941; 15 to polyvinyl resin-containing emulsions generally. Lowe 2,276,322, Mar. 17, 194.2; Lowe 2,276,323, However, it is of particular advantage‘ in con‘ Mar. 1'7, 1942, and Lowe 2,236,215, June 16, 1942. It will be noted that these patents specify cer tain ranges of vinyl alcohol content which are nection with the processingof polyvinyl resin emulsions which have poor permeability to proc essing baths. ‘Thus polyvinyl esters which con most permeable to photographic processing baths. 20 tain above about 71% of polyvinyl ester are slow‘ These patents also indicate that outside these ly penetrated. Other, polyvinyl resins such as the-acetaldehyde, butyraldehyde etc.v acetals are in certain cases, especially in the higher acetal 25 content range.iimpermeable or slowly permeable tional processing baths. to processing baths. ‘Ourinvention is. therefore, This invention has for its object to provide of particular ‘advantage in‘ connection with the improved methods for processing polyvinyl resin treatment or processing ofs'uc-h emulsions. How photographic emulsions. Another object is to provide improved processing baths for photo ever, it is applicable to emulsions which can be ranges, and in certain cases inside certain por~ tions of these ranges, difficulty is encountered in connection with lack of permeability to conven graphic elements which include a layer of a poly 30 processed with conventional _--proce_ssing baths vinyl resin which contains a silver salt and which since the thiocyanate ~wil1<;increase the ratev of penetration and rate of developing or ?xation. is not readily permeable to usual processing baths. A still further object is to provide a Therefore. it is to be understood that the fore method for treating an exposed photographic going resins which are slowly or incompletely element which includes a layer of a polyvinyl 35 penetrated constitute the preferred embodiment of our invention. resin containing a silver salt whereby its per meability to the processing bath is increased and The thiocyanates can be added to the develop whereby the processing time is substantially re ing and ?xing baths in greatly varying amounts duced. Other objects will appear hereinafter. depending upon the degree of permeability and These and other objects are accomplished by 40 speed of penetration desired. For most purposes our invention which includes treating an ex between about one and one hundred grams per posed photographic element including a layer of a liter of processing solution will be found to be polyvinyl resin which contains a silver salt and satisfactory. For developing solutions we pre which is not su?iciently permeable to the usual for to add about one to ?fty grams of thiocyanate 45 processing baths with a processing bath which per liter of developer. For‘ purposes of ?xation contains a thiocyanate. It has been found that one to one hundred grams per liter are generally the rate of penetration is greatly increased by useful, but we prefer to employ thiocyanate in the presence of this material in the processing the upper portion of the range mentioned; i. e., bath and that the speed of development, ?xation, about ?fty to one hundred grams per liter of etc. is correspondingly increased. ?xing solution. In the following examples and description we In some cases it may be advantageous to add an amine such as ethanol amine, triethanol of our invention, but it is to be understood that amine to the baths especially the ?xing bath, to these are set forth for the purpose of illustra 55 avoid or prevent opalescence in the dried ?lm. tion and not in limitation thereof. have given several of the preferred embodiments 2,409,107 3 2 minutes at 70° F. The ?lm had good contrast and was ?xed in 3 minutes by treatment with a bath containing 100 grams of sodium thiocyanate Example I A silver halide emulsion was prepared by dis persion of the halide in a polyvinyl acetaldehyde and 100 cc. of ethanolamine per liter of 30 per acetal which contained about 35 per cent unre Li cent hypo. acted polyvinyl alcohol and this emulsion was D-l6 developer is manufactured by Eastman Kodak Company and is made up of the following: coated upon a ?exible ?lm base in known manner and photographically exposed. When treated in Water, 50° C _______________________ __cc__ 750 a conventional developer such as diluted D-72 ,Monomethyl-paraminophenolsulfate (diluted 1 part developer to _2 parts water) the development took place in ten minutes with poor contrast. grams__ The same ?lm exposed in the .same .Hydroquinone __________________ __do____ 6 NazCOa (£165.) ___________________ __do____ 18.7 way was developed in D-‘72 developer (diluted 1 :2) to which had been added 10 grams per liter of sodium thiocyanate. The development in this solution took place in two minutes and the con trast was markedly improved. D-72 developer is manufactured by Eastman Kodak Company and is made up of the following: Monomethyl-paraminophenolsulfate grams" 3.1 .45 Hydroquinone ___._.___________.___do...__ 12 NazCOs (des) ___________________ __do____ 67.5 KBr ________ ____ ________________ __do____ 1.9 Water to make ___________________ __liter__ 1 'KBr ____________________________ __do____ .86 Citric acid__-_ ____________________ __do____ ‘Potassium metabisul?te ___________ __do____ Cold water to make _______________ "liter" .68 1.5 1 ‘What we claim is: Water, 50° C _______________________ ..-c;:.. 500 Y 20 Sodium .sul?te (des).____________.__'do____ .31 Sodium sul?te (des.) _____________ __do__.._ 39.6 ' 1. The method of treating an exposed pho g‘raphic element which comprises immersing the element including a layer of a polyvinyl resin which contains a silver salt and which ‘is not readily permeable to processing baths, in a proc essing bath which contains an inorganic thio cyanate and ethanolamine. 2‘. The method of treating an exposed pho~ tographic element which comprises immersing Example II Film carrying 'the emulsion described in Ex the element including a layer of a polyvinyl resin which contains a silver salt and which is ample I was exposed, developed and then ?xed in a simulated conventional ?xing bath containing not readily permeable to processing baths, in a processing bath which contains an inorganic 30 per cent hypo. The rate of ?xation was 2 hours and '30 minutes. Addition of 100 grams of sodium thiocyanate per liter of the '30 per cent hypo reduced the time of ?xation to 3 minutes. thiocyanate and an ethanolamine. tographic element which comprises immersing Example III which is not readily permeable to developing 3. The method of developing an exposed pho the element including a layer of a polyvinyl acetal resin which contains a silver salt and baths, in a developing bath which contains an in Five grams of sodium thiocyanate per liter of diluted developer D-72 (diluted, 1:2) developed the photographic ?lm described in Example I in 2 minutes at 70° F. The developed ?lm had good contrast. The ?lm so (developed was ‘?xed in .3 minutes by treatment with .a bath containing .100 grams sodium thiocyanateand .100.cc.,of ethanol amine per liter of 30 per cent hypo. Example IV Five grams of sodium thiocyanate per liter of diluted- D-l6 developer (diluted 1;2) developed the photographic ?lm described "in‘Example I in 40 organic thiocyanate and ethanolamine. 4. The method of ?xing an exposed and. de . veloped photographic element which comprises immersing the element including a layer of poly vinyl acetal resin which contains a silver image and a silver salt and which is not readily ‘per meable to ?xing baths in a ?xing bath ‘which . contains an inorganic thiocyanate and ethanol amine. JOHN ‘I. CRABTREE. GEORGE T. EATON.