- 2,979,406 United States Patent Office Patented Apr. 11, 1961 1. 2 Any of the usual alkali metal polyphosphates may be employed such as sodium hexametaphosphate, potassium 2,979,406 hexametaphosphate and the like. Best results, however, SINGLE POWDER PHOTOGRAPHICDEVELOPERS are achieved by use of the sodium hexametaphosphate 5 and the use of this compound is, accordingly, preferred. John B. Taylor and Jerry S. Krizka, Binghamton, N.Y., The photographic developing agent may be any of assignors to General Aniline & Film Corporation, New those previously mentioned and it may be used alone York, N.Y., a corporation of Delaware - or in admixture with other developing agents. Typi No Drawing. Filed Apr. 11, 1956, Ser. No. 577,452 cally, we may use a mixture of N-methyl-p-aminophenol O and hydroquinone, metol and 1-phenyl-3-pyrazolidone 8 Claims. (C. 96-66) (phenidone), phenidone and hydroquinone or phenidone, The present invention relates to single powder photo N-methyl-p-aminophenyl and hydroquinone. graphic developers in which all of the essential ingredients The preservative is preferably sodium sulfite usually of the developer are intimately admixed in dry powder in the anhydrous condition and the anti-fogging agent form and, more particularly, to an improved stabilizer 15 is potassium bromide. The alkali may be any of those for such developers. used in compounding photographic developers, such as Single powder photographic developers contain as sodium carbonate, sodium hydroxide, sodium tetraborate, their essential ingredients one or more organic develop sodium metaborate or the like. ing agents such as N-methyl-p-aminophenol, hydro In compounding the aforesaid developer mixtures, one quinone, 1 - phenyl-3-pyrazolidone, para-aminophenol 20 may proceed by first mixing the alkali metal polyphos monohydrochloride, pyrogallol, an alkali such as so- - dium carbonate, borax, sodium metaborate or the like, phate with the acidic stabilizer or stabilizers, adding and a preservative such as an alkali metal sulfite and an anti admixing the alkali, then the developing agent and finally foggant such as potassium bromide. Under ordinary the other ingredients. However, if it be preferred, all conditions of mixing and storage, such dry developers 25 the ingredients may be admixed simultaneously. undergo decomposition reactions which adversely affect It is to be emphasized that the alkali metal polyphos the photographic activity of the developers. phates, per se, have no stabilizing effect whatsoever on The art has been cognizant of this phenomenon and, single powder photographic developers. In other words, in an effort to avoid it, has provided for the presence no useful result would be performed by admixing an in such developers of an acidic stabilizer such as phthalic 30 alkali metal phosphate such as sodium hexametaphos acid, anhydrous oxalic acid, boric anhydride, metaboric phate with the essential components of a single powder acid, potassium metabisulfite and the like. While these photographic developer from the standpoint of achiev. various acid stabilizers serve to promote the keeping ing stability thereof, either in the preparation or in stor qualities of such developers, they do not lead to optimum 35 age of such developer. However, when the alkali metal results, as is evident by the fact that developers con polyphosphate is present with one of the usual acidic taining the same generally discolor within a period of stabilizers, it serves to greatly promote the stabilizing two to three months. - effect, an action which appears to be synergistic in char It is known that alkali metal polyphosphates have acter. Thus, as noted, single powder developers con utility in photographic developers as sequestering agents 40 for the salts which cause hardness of water. When taining sodium hexametaphosphate even in the quantities used for this purpose, the alkali metal phosphates are heretofore specified, in the absence of an acidic stabilizer, employed in small amounts, i.e., usually less than one show no improvement over similar single powder de gram per-liter. ... ------velopers free from the acidic stabilizer. Single pow We have now discovered that the stabilizing ability der developers containing the usual acidic stabilizers ab of the usual acidic stabilizers for single powder photo 45 sent the sodium hexametaphosphate discolor in a period graphic developers...is. Surprisingly promoted by using of a few months. When, however, the acidic stabilizers with said stabilizers, a substantially higher quantity of and the alkali metal polyphosphate in the noted quan an alkali metal polyphosphate than is used when the tity are present together in a single powder developer, polyphosphate is to operate as a sequestering agent. Dry 50 the stability of the developer is greatly magnified and powder developers containing the usual acidic stabilizers no discoloration appears even after storing the developer with such higher quantities of alkali metal polyphosphates for more than 12 months. It is manifest, the facts being constitute the purposes and objects of the present in as stated, that the results must be attributable to some vention.The developers . . which are contemplated. . . . herein- . . . contain. . . . . peculiar coaction between the hexametaphosphate and as their essential components an alkali metal polyphos 55 the acidic stabilizer which serves to greatly intensify phate, an organic developing agent, an alkali, a pre the stabilizing action of the acidic component. servative, an anti-fogging agent and an acid stabilizer." The following examples will serve to illustrate our. Developers with these components which we have found invention, the parts being by weight. - - - to be stable during mixing and during storage, for con 60 siderable periods of time be compounded in the - : ... Example I. - . . . . Grams following proportions, it being understood that the re sulting dry powder is to be used to make a liter of de Sodium hexametaphosphate------2:0 veloping solution: Ethylene diamine tetra acetic acid- I 0.7 Grams 65 Phthalic acid.------0.5 An alkalimetal polyphosphate. Potassium metabisulfite------6.0 Organic developing agent. Sodium carbonate, monohydrate--- 30.O. Alkali------Sodium sulfite, anhydrous------400 Preservative ------N-methyl-p-aminophenol--- : 20 Anti-fogging agent ------Acid stabilizer ------

3,978,406 -- - 3. Example II lowing amounts of these ingredients per liter of solu Grams tion: Sodium hexametaphosphate------3.0 Grams Ethylene diamine tetra acetic acid.------1.0 Alkali metal hexametaphosphate------1 to 8 Oxalic acid (anhydrous)------0.3 Organic photographic developing agent------4 to 15 Potassium metabisulfite------2.5 An alkali selected from the group consisting Borax, pentahydrate------5.0 of sodium carbonate, sodium hydroxide, so Sodium sulfite, anhydrous------100.0 dium tetraborate and sodium metaborate--- 5 to 100 N - methyl-p-aminophenol------1.2 O Alkali metal bisulfite------30 to 120 Hydroquinone ------8.0 Antifogging agent------.5 to 2 Potassium bromide------0.5 Acid stabilizer selected from the group con sisting of phthalic acid, anhydrous oxalic Example III Grams acid, boric anhydride, metaboric acid and Sodium hexametaphosphate------4.0 5 potassium metabisulfite------5 to 12 Ethylene diamine tetra acetic acid------0.8 3. The composition as defined in claim wherein suf Phthalic acid------10 ficient alkali metal hexametaphosphate is employed to Potassium metabisulfite------losed.ass 10.0 Sodium carbonate, monohydrate------80.0 produce about 1 to 8 grams thereof per liter of devel Sodium sulfite, anhydrous------50.0 20 oper solution. Phenidone ------25 4. A single powder developing composition containing N - methyl-p-aminophenol------1.0 sufficient of the following ingredients to produce, upon Hydroquinone ------7.5 dissolution, a developing solution having the following Potassium bromide------15 25 amounts of these ingredients per liter of solution: Grams Example IV Grams Sodium hexametaphosphate------2 Sodium hexametaphosphate------6.0 Ethylene diamine tetra acetic acid------7 Ethylene diamine tetra acetic acid------0.8 30 Phthalic acid------5 Metaboric acid------2.0 Potassium metabisulfite------6 Potassium metabisulfite------3.0 Sodium carbonate, monohydrate------30 Sodium carbonate, monohydrate------8.0 Sodium sulfite, anhydrous.------40 Sodium sulfite, anhydrous------100.0 N - methyl-p-aminophenol------2 Phenidone ------.15 35 Hydroquinone ------5 Hydroquinone ------4.5 Potassium bromide------1. Potassium Bromide------0.5 5. A single powder developing composition contain Example W ing sufficient of the following ingredients to produce, Grams 40 upon dissolution, a developing solution having the foll Sodium hexametaphosphate------2.0 lowing amounts of these ingredients per liter of solu Ethylene diamine tetra acetic acid.------0.8 tion: Boric anhydride------0.75 Grams Potassium metabisulfite------6.0 Sodium carbonate, monohydrate------20.0 s Sodium hexametaphosphate------3 Sodium Sesqui-carbonate------8.0 Ethylene diamine tetra acetic acid------Sodium sulfite, anhydrous------am mwy wa way a was 50.0 Oxalic acid (anhydrous)------.3 N - methyl-p-aminophenol------3.5 Potassium metabisulfite------2.5 Hydroquinone ------7.0 Borax, pentahydrate------5 Potassium bromide------1. 5. Sodium sulfite, anhydrous------100 The quantity of the developer represented by the above N - methyl-p-aminophenol------1.2 formulae is to be dissolved in water to make one liter of Hydroquinone ------8 developing solution. Potassium bromide------5 Modifications of the invention will occur to persons 55 skilled in the art. We, therefore, do not intend to be 6. A single powder developing composition containing limited in the patent granted except as necessitated by sufficient of the following ingredients to produce, upon the appended claims. dissolution, a developing solution having the following We claim: amounts of these ingredients per liter of solution:. . 1. A single powder photographic developing composi Grams tion containing an organic photographic developing Sodium hexametaphosphate------4 agent, an alkali metal sulfite, an alkali selected from the Ethylene diamine tetra acetic acid------8 group consisting of sodium carbonate, sodium hydroxide, Phthalic acid------sodium tetraborate and sodium metaborate, an anti Potassium metabisulfite------. 10 fogging agent, a sufficient amount of an acid stabilizer 65 Sodium carbonate, monohydrate------80

selected from the group consisting of phthalic acid, an: Sodium sulfite, anhydrous------SO hydrous oxalic acid, boric anhydride, metaboric acid and Phenidone ------25 potassium metabisulfite to produce 0.5 to 12 grams, per N - methyl-p-aminophenol------. 1. liter in solution and a sufficient amount of alkali metal O Hydroquinone ------7.5 hexametaphosphate to produce at least 1 gram per liter Potassium bromide------15 in 2.solution. A single powder - .developing . . . . composition:: . . . . .contain . - 7. A single powder developing composition contain ing sufficient of the following ingredients to produce, ing sufficient of the following ingredients to produce, upon dissolution, a developing solution having the fol upon dissolution, a developing solution having the fol 2,979,406 5 6. lowing amounts of these ingredients per liter of solu- - Grams tion: Sodium sesqui-carbonate.------8 Grams Sodium sulfite, anhydrous------50

Sodium hexametaphosphate------6 5 G Eminephenol ------a ------35 Ethylene diamine tetra acetic acid------.8 E. rail mid------a ------1.2 Metaboric acid------2 OtaSSill DIOhildC.------SodiumPotassium carbonate, metabisulfite------monohydrate.------38 References Cited in the file of- this patent Sodium sulfite, anhydrous------100 0. UNITED STATES PATENTS

Eation- - - a a ------a -a - - - -- a------a 4. 2,239,28 Draisbach ------Apr. 22, 1941 E"Sonide. I 5 2,541,470 Henn et al. ------Feb. 13, 1951 a . . . . A - - - ar. ------a ------2,610,122 John et al. ------Sept. 9, 1952 8. A single powder developing composition containing 2,688,549 James et al. ------Sept. 7, 1954 sufficient of the following ingredients to produce, upon 15 FOREIGN PATENTS dissolution, a developing solution having the following amounts of these ingredients per liter of solution: 520,753 Great Britain ------May 2, 1940 Grams 734,534 Germany ------Nov. 4, 1943 Sodium hexametaphosphate------2 20 743,534 Germany ------Dec. 29, 1943 Ethylene diamine tetra acetic acid------.8 OTHER REFERENCES Boric oanhydride------o .75 Photo-Lab-Index, pages 13-35 and pages 13-36, Mor Potassium metabisulfite------6 gan and Lester Publishers, New York, N.Y. Sodium carbonate, monohydrate------20 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,979, 406 April 11, 196l John B. Taylor et al. It is hereby certified that error appears in the above numbered pat ent requiring correction and that the said Letters Patent should read as corrected below. Column 2 line lo, for "metol" read -- N-methyl-p- aminophenol -- Signed and sealed this 10th day of October 196l.

(SEAL) Attest: ;' ERNEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of Patents USCOMM-DC.