CA1055763A - Photographic color developer compositions - Google Patents

Abstract

Abstract of the Disclosure Photographic color developer compositions containing a primary aromatic amino color developing agent and an hydroxylamine salt are stabilized by incorporating therein the sequestering agent 1,3-diamino-2-propanol tetraacetic acid and a diphosphonic acid sequestering agent. Decomposition of the hydroxylamine salt, in the presenct of heavy metals such as irom which act to catalyze the decomposition, and resultant formation of ammonia is effectively prevented by the presence in the developer composition of this combination of sequestering agents.

Description

55~
This invention relates in general -to color photograph~
and in particular to new and improved color developing compo-sitions and processes for forming photographic color imagesO
More specifically, this invention relates to color development with a color developing composition containing a primary aromatic amino color developing agent and an hydroxylamine salt which is stabilized by the presence of a combination of sequestering agents~
The formation of color photographic images by the image-wise coupling of oxidized primary aromatic amino develop-ing agents with color forming or coupling compounds to form indoaniline, indophenol, and azomethine dyes is well known. In these processes, the subtractive process of color formation is ordinarily used and the image dyes customarily formed are cyan, magenta, and yellow, the colors that are complementary to the primary colorsg red, green, and blue, respectively. Usually phenol or naphthol couplers are used to form the cyan dye image;
pyrazolone or cyanoacetyl derivative couplers are used to form the magenta dye image; and acylacetamide couplers are used to form the yellow dye image.
In these color photographic systems, the color-forming coupler may be either in the developer solution or incorporated in the ligh~-sensitive photographic emulsion layer so that3 during development~ it is available in the emulsion layer to react with the color developing agent that is oxidized by silver image development. Diffusible couplers are used in color developer solutionsO Nondiffusing couplers are incorporated in photographic emulsion layers. When the dye image formed is to be used in situ, couplers are selected which form non-diffusing dyes~ For image transfer color processes, couplers 5~i3 are used which will produce dilfusible dyes capable of beingmordanted or fixed in the receiving sheet.
It is common practice in the photographic arts to include an hydroxylamine salt in color developer compositions containing primary aromatic amino color developing agents.
For example, hydroxylamine salts are used in color developers as antioxidants and, as described in United States patent 3,141,771, an hydroxylamine salt can be incorporated in a color developer to improve the properties of balancing develop-ing agents. However, a problem is presented by the factthat the hydroxylamine salt tends to decompose in the developer to generate ammonia and, as is well known, the ammonia can produce adverse sensitometric effects such as the formation of cyan stain in color photographic elements. As disclosed - 15 in United States patent 2,875,049, the sequestering agent 1,3-diamino-2-propanol tetraacetic acid functions as a stabilizer ~or developer compositions containing an hydroxyl-amine salt. However, this sequestering agent is not effective in preventing the decomposition of hydroxylamine salts in developer compositions which contain heavy metals, such as iron or copper, which function to catalyze the decomposition.
This is a significant limitation on the usefulness of this sequestering agent in the photographic arts since it is common for small amounts of heavy metals to be present in developers, for example~ iron salts which are utilized in bleach or bleach-fix compositions in many methods of processing photographic e]ements can contaminate the color developer, or iron oxide used in inks employed to mark indicia on photographic prints can be deposited in color developers.

Disphosphonic acid sequestering agents, such as are described in United States patent 3,214,454, can be employed in color developer compositions and the sequestering agent l-hydroxyethylidene-l,l-diphosphonic acid is, in particular, very effective in preventing the decomposition of hydroxylamine salts in developers containing heavy metals such as iron which function to catalyze such decomposition. Use of hydroxyalkyl-idene diphosphonic acid sequestering agents in neutralizing baths which contain hydroxylamine salts in order to stabilize the bath against decomposition of the hydroxylamine salt is described in United States patent 3,647,449. However, when an hydroxyalkylidene diphosphonic acid sequestering agent is incorporated in a photographic color developer a problem occurs in that such developers con-tain alkali metal ions such as sodium or potassium ions and as a result a precipitate of the hydroxyalkylidene diphosphonic acid sequestering agent is formed. This precipitate is believed to be a salt o~ the sequestering agent such as the disodium monocalcium salt or the monosodium monopotassium monocalcium salt. This problem of precipitate formation and a solution to the problem are disclosed in United States patents 3,794,591 issued February 26, 1974 and 3,839,o45 issued October 1, 1974. The solution to the problem which is disclosed in the aforesaid patents is the incorporation of lithium ions in the developer solu-tion, such as by the use of lithium carbonate or lithium sulfate, whereby the formation of the precipitate is prevented.
However, this solution to the problem suffers from the dis-advantage that addition of a lithium salt to the developer composition adds substantially to the total cost~

~ '~` .

3~55763 In view of the facts described above~ it is apparent that the prior art does not provide a fully satisfactory solution to the problem of stabiliz:ing color developer solutions which contain hydroxylamine salts and are contaminated by heavy metals, such as iron, which catalyze the decomposition of such salts. Thus, use of 1,3-diamino-2-propanol tetraacetic acid by itself will result in a developer composition that undergoes decomposition in the presence of heavy metals, such as iron, to an extent that is undesirable. On the other hand, use of 1-hydroxyethylidene~ diphosphonic acid by itself will substantially prevent the decomposition but result in undesirable formation of a precipitate and addition of the lithium salt to the developer composition to avoid precipitate formation will increase costs to an extent sufficient to hinder the commercial utilization of the developer composition.
In accordance with this invention~ it has now been discovered that the problem described above can be solved by incorporating in the developer composition both 1,3-diamino-2-propanol tetraacetic acid and a diphosphonic acid sequestering agent. It has been unexpectedly discovered that the combination of these two sequestering agents will significantly decrease the extent of decomposition of hydroxylamine salts in color developer compositions, even when such compositions contain heavy metals such as iron which catalyze the decomposition, and that use of the combination of sequestering agents makes it unnecessa~y to incorporate a lithium salt in the developer in order to prevent precipitate formationO
The primary aromatic amino color developing agents -that can be utilized in the compositions and methods of this invention are well known and wideIy used in a variety of color photographic processesO They include aminophenols and , ... .

.. ~ . - . , , " . .- . , .. ,. :, :: ~

~55~7~:i3 p-phenylenediamines. They are usually used in the salt form, such as the hydrochloride or sul~ate, as the salt ~orm is more stable than the ~ree amine, and are generall.y empl.oyed in concentrations o~ from about 0.1 to about 20 grams per liter of developing solution and more pre~erably from about 0.5 to about 10 grams per liter o~ developing solution~
Examples of aminophenol developing agents include o-aminophenol, p-aminophenol3 5-amino-2-hydroxy-toluene, 2-amino-3-hydroxy-toluene, 2-hydroxy-3-amino-1,4-dimethyl-ben~ene, and the like.
Particularly useful primary aromatic amino color developing agents are the p-phenylenediamines and especially the N,N-dialkyl-p-phenylenediamines in which the alkyl groups or the aromatic nucleus can be substituted or unsubstituted~
Examples of use~ul p-phenylenediamine color developing agents include N,N-diethyl-p-phenylenediamine monohydrochloride, 2-amino-5-diethylaminotoluene monohydrochloride, 4-amino-N-ethyl-N-~-methanesulfonamidoéthyl]-m-toluidine sesquisul~ate mono-hydrate, 4-amino-3-methyl-N-ethyl-N-[~-hydroxyethyl]-aniline sul~ate, 4-amino-3-(~-methylsulfonamidoethyl)-N,N-diethyl-aniline hydrochloride, 4-amino-N,N-diethyl-3-(N'-methyl-~-methylsulfonamido)-aniline hydrochloride and similar color developing agents disclosed in U.S. Patent Nos. 2g552g241 and

2,566,271. An especially pre~erred class of p-phènylenediamine developing agents are those containing at least one alkyl sul~onamidoalkyl substituent attached to the aromatic nucleus or to an amino nitrogen. Other especially preferred classes o~ p-phenylenediamines are the 3-alkyl-N-alkyl-N-alkoxyalkyl-p-phenylenediamines and the 3-alkoxy-N-alkyl-N-alkoxyalkyl-p-phenylenediemlnes. These develop ne agents are described in 5~763 United States patents 3,656,950 and 3,658,525 and can berepresented by the formula:
CH3 - CH2 _ ~ (CH2)n ~1 .

where n is an integer having a value of from 2 to 4~ R is alkyl of from l to 4 carbon atoms, and Rl is alkyl of ~rom l to 4 carbon atoms or alkoxy of from l to 4 carbon atoms.
Illustrative examples of these developing agents include the following compounds:
N-ethyl-N-methoxyethyl-3-methyl-p-phenylenediamine N-ethyl-N-methoxybutyl-3-methyl-p-phenylenediamine ~-ethyl-N-ethoxyethyl-3-methyl-p-phenylenediamine N-ethyl-N-methoxyethyl-3-n-propyl-p-phen~lenediamine N-ethyl-N-methoxyethyl-3-methoxy-p-phenylenediamine N-ethyl-N-butoxyethyl-3-methyl-p-phenylenediamine and the like.
In addition to the primary aromatic amino color developing agent, the developer compositions of this invention contain a salt of hydroxylamine. Such salts are typically acid addition salts such as hydroxylamine sulfate3 hydroxylamine hydrochloride, hydroxylamine phosphate, and the li~e.
As described hereinabove, the novel color developer compositions of this invention contain the sequestering agent 1,3-diamino-2-propanol tetraacetic acid. In its commercially available forms, this sequestering agent is often present in admixture with minor amounts of nitrilotriacetic acid, for example ten to twenty percent by weight of nitrilotriacetic acid. Such mixtures of a major amount of 1,3-diamino~2-propanol : ' .... . . . .... . .. . . . . .. .. .. ..... .. .. .. .... . . .. ..

~57~i3 tetraacetic acid and a minor amo~t of nitrilotriacetic acid can be employed with satisfactory results in the developer compositions of this inventionO
In addition to the 1~3-diamino-2-propanol tetraacetic acid, the developer compositions o~ this invention also contain a diphosphonic acid sequestering agent. Mixtures of two or more diphosphonic acid sequestering agents can be used if desired.
The hydroxyalkylidene diphosphonic acid sequestering agents are especially useful for the purposes of this invention3 particularly those of the formula:

R - C - OH

3 2 in which R is alkyl of one to five carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, n-pentyl, and the like.
Other useful diphosphonic acid sequestering agents include the aminodiphosphonic acid sequestering agents of the formula:

in which R3 is alkyl of one to five carbon atoms. Typical examples of the hydroxyalkylidene diphosphonic acids are 1-hydroxyethylidene-l~l-diphosphonic acid and l-hydroxypropyli-dene-l, l-diphosphonic acid while typical examples of the aminodiphosphonic acids are l-aminoethane-l,l-diphosphonic acid and l-aminopropane-l,l-diphosphonic acid The developer compositions of this invention contain an effective amount of both the 1~3-diamino-2-propanol tetra~

acetic acid and the diphosphonic acid sequestering agent~
Typically the 1,3-diamino-2-propanol tetraacetic acid will be 7~3 used in larger amounts, on a molar basis, than the diphosphonic acid sequestering agent since the essential function of the 1,3-diamino-2-propanol tetraacetic acid will be to sequester calcium while the essential func-tion of the diphosphonic acid sequestering agent will be to sequester iron and the iron will typically be present in smaller amounts than the calcium. How-ever3 the particular amount of each sequestering agent which is optimum will depend upon the particular de~eloper composition involved, and the metal ions ~rhich are present therein, and in particular instances either one of the two sequestering agents can be used in higher concentration than the other. Generally speaking, the developer solution will contain from about 0.0002 to about 0.05 moles of 1,3-diamino-2-propanol tetraacetic acid per liter of solution3 more typically from about OD 001 to about 0.02 moles per liter, and preferably from about 0~005 to about 0.01 moles per liter. It will also contain from about 0.0001 to about OoOl moles of diphosphonic aeid sequestering agent per liter of solution, more typically from about 000002 to about 0.004 moles per liter, and preferably from about 0.0005 to about 0.001 moles per liter.
A preferred combination of sequestering agents for the purpose of this invention is a eombination of l,3~diamino-2-propanol tetraacetic acid which has the formula:

HOOC - CH2~ ~ CH2 - COOH
~ N-CH2 CH - CH - N
HOOC - CH2~ OH 2 ` CH2 - COOH
and l-hydroxyethylidene-l,l-diphosphonic acid which has bhe for~ula:

_ 9_ . , ' : .

~5~6~ :

In addition to the primary aromatic amino color developing agent, the hydroxylamine salt, the 1,3-diamino-2-propanol tetraacetic acid and the diphosphonic acid sequester-ing agent, the developer compositions of this invention can also contain any of the various components that are ordinarily incorporated in color developing solutions, for example, mater-ials such as alkalies, alkali metal sulfites, alkali metal bi-sulfites, alkali metal thiocyanates, alkali metal bromides, alkali metal iodides, benzyl alcohol, thickening agents, water softening agents, and so forth. The pH of the developing solution is ordinarily above 7 and most typically about 10 to about 130 Development of photographic elements in the color developing compositions of this invention can be advantageously employed in the processing of photographic elements designed for reversal color processing or in the processing of negative color elements or color print materials. The developer compo-sitions can be employed with photographic elements which are processed in color developers containing couplers or with photographic elements which contain the coupler in khe silver halide emulsion layers or in layers contiguous thereto. The photosensitive layers present in the photographic elements processed according to the method of this invention can contain any of the conventional silver halides as the photosensitive material, for example, silver chloride, silver bromide, silver bromoiodide, silver chlorobromide3 silver chloroiodide, silver chlorobromoiodide, and mixtures thereof. These layers can contain conventional addenda and be coated on any of the photo- ;
graphic supports, such as, for example, cellulose nitrate film, cellulose acetate film, polyvinyl acetal film, poly~
carbonate film, polystyrene film, polyethylene terephthalate . .

~5~ 3 film, paper, polymer-coated paper, and the like.
The invention is further illustrated by the following examples of its practice.

A photographic color developer was prepared with the following composition:
Benzyl alcohol - 14.5 milliliters Hydroxylamine sulfate - 3.4 grams * Color developing agent - 4.3 grams Potassium sulfite - 3OC7 grams Potassium bromide - 0O34 grams Potassium carbonate - 31.0 grams Lithium sulfate - 1.78 grams Water to make one liter 15 * 4-Amino-N-ethyl-N-(~-methanesulfonamido-ethyl)-m-toluidine sesquisulfate monohydrate Sequestering agents were incorporated in samples of this developer composition as described in Table I below and ferrous chloride was added to certain of the sampl.es in an amount sufficient to give a concentration of ~errous ion as indicated in Table Io A portion of each sample was stored in a 1000-milliliter graduated cylinder open to the atmosphere and analyzed periodically for ammonia generation over a period of two months. For. certain of the samples a second portion was stored in a closed bottle and analyzed periodically for ammonia .
generation over a period of two monthsO
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O _ N N ~ a rt O rt N ~ ~ ~ U V

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t O O O O O O O O O O O O rt O ~i O O O ~ ~ ~ O

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Results of the tests for ammonia generation in the closed samples are given in Table III below, in which the values reported represent the concentration of ammonia in the developer solution measured in milligrams per liter at the specified number of days from the s-tart of the test~

TABLE III

Days From Start of Test Test ~o. 0 14 28 53 55 56 57 2 7 1 3 __ ~
3 28 184 219 -- -- ~~ 37

4 20 185 244 -- -- -- 288.

15 6 5 2 4 -- __ __ __ :
7 8 7 16 __ 17 __ 9 10 3 6 -- __ 4 __ 13 2 5 27 -- __ 8 --14 3 13 26 __ 65 -- __ 3 14 26 -- 49 __ 2516 2 15 20 44 -_ __ __ 17 4 30 5 143 -- -- ~~ : -~
18 3 16 35 58 -- __ _ : 19 3 3 -- 6 -- -~

As shown by the data in Tables I, II and III3 when both the sequestering agent 1,3-diamino-2-propanol tetra-acetic acid and the sequestering agent l-hydroxyethylidene 1, l-diphosphonic acid are added to the color developing solution in e~fective amounts the e~olution of ammonia is suppressed whether or not iron is present in the solut,ionO For example, ~5~3 , ~ests 73 8~ 11, 12~ 26 and 27 descri.be developer solutions containing iron, 1~3-diamino-2-propanol tetraacetic acid and l-hydroxyethylidene~ diphosphon:ic acid and these under~
went formation of ammonia to only a very limited extentO In tests 3 and 4 there is an insufficient amount of l-hydroxy-ethylidene-l, l-diphosphonic acid for the amount of iron present so extensive ammonia generat;ion took placeO The data of Tables I3 II and III also show that the sequestering agent l-hydroxyethylidene-l, l-diphosphonic acid by itself is effective in preventing the generation of ammonia in a developer composition containing iron if used in a suffici.ent amount. This is shown by test number 220 However3 use of this sequestering agent by itself in amounts sufficient to prevent the ammonia generation results in the formation of 1~ an undesirable precipitate in the developer solution, unless lithium ions are incorporated in the solution in a sufficient;
amount to prevent such precipitate formation~ This is shown by tests in which a developer composition as described herei.n~
above was prepared, the concentrations of sodium, lithium and calcium ions were varied as indicated, the solutions were - stored in covered l-liter beakers3 and the solutions were analyzed periodically for the presence of a precipitate of l-hydroxyethylidene-13 l-diphosphonic acid. The results are reported in Table IV.

~16-i~l35~ 3 0 C~
~ 0 ,, ., ,, ,,_ C C o C
V ~ ~ ~ ~

5 ~ C 5 5 C 5 C
O O 0 0 0 ~ O ~
V ~ ~, V 6~ V
0 ~ ~ ~ 0 5~ a ~
V~V .~V'.l==_======-===_===
R ~ 0 ~1, D. O Q~ 0 ~rl .r~ h ~rl ~I h ~I h O O D. O O 1~. 0 t~-h ~ ~ ~ ~ ~ C = = = -- = = = = = = = -- = = = = =
C . ~

V H O C O O O O ol' OJ ~ O O ~t C~.l O ~ CU O
oo oo oo oo oo oo oo oo-O
. ' ' ~0 .~ ~` .
~ ~a H O C ~I ~ 10 0 0 0 0 0 ~ 1 ~1 0 0 0 0 0 0 r-l r l ~1 0 0 0 D~ S 0 O O O O O O O' O' O' O' O' O 0 0 0 O' O' O' O O' O 0 0 0 .
~ .. `~

HO ~ ~L ~ ~0 0 ~0 ~ ~ ~ O O O 0 0 O 0 0 0 O 0 O
C~

' ~ V _ c~ ~ ~ h ' , -~ ~ ~ ~ O O O O O O O O O U~ ~ O O o o o o 0 ~1 C~i N N N N N N N CU N . N N CU I U N
C Cll`~
O~

O
C
s: c 5J . ! . . ! c . . . . . . .
OC 3~ 1 ~ I rl ~ ~ i ~ O O O O O O C~ O 0-0 0 O O O O
.~ n 8 . . .

.. .

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:~55~7~ii3 O O = = U~ ~ ~ U~ = ~ U~ = = = = = = . = = = = = = =

C~ V ~
==.1VV.~=V_~===.=========-=
~ O O ~
O ~ R. O O R- O ~.
G ~: - ~ S~ = = = = = = = = = - = =

O H V~ N O t C~l O t N O t o O ~ C~J O ~ N O N O t O
OOOO OO OO OO OO OO OO

~ol C _ ¦ O O ~ 1 ~1 0 0 0 0 0 0 ~1 ~1 _I ~0 0 ~ N N ~1 H ~ ~
~ ~ ' .
~ . ~
~ ~o ~ ~ o o o o o o o o o o o o o o o o o o o o o o o o H F. ~ 'I 'i ~ N N N N ~;J N N NO ON N NO NO ON ON c~ o O o o o o ~0' 4_~ O O O O O O O O O O O O 1~ ~ O O O
h ~ W N OJ N N N N N N ~ N N N C~i ~0 . , .
' ' ' 1`` ~
~8 : ~
- l & - :

~557~i~

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cB
o LS~ = = = = =
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a~
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U~~' 35~i7~3 As shown by the data in Table IV3 when a li.thium salt is omitted from a developer solution containing l-hyd:roxy-ethylidene-l, l-diphosphonic acid as the sole sequestering agent, a precipitate is formed in most instances after a rel.atively short period of storage, with the ti.me required being dependent on such factors as the concentration of sodium and calcium ions in the solutionD The formation of such a precipitate adversely affects the performance of the developer solution so that it is very desirable that the developer be capable of storage for a relatively long period of time without precipitate formation.
Use of the combination of sequestering agents described herein makes it possible to store the developer solution for long periods without precipitate formation and without the need for a lithium saltO

EXAMPL~ 2 A photographic color developer was prepared with the following composition:
Benzyl alcohol 12 milliliters * Color developing agent 5.5 grams Potassium sulfite 301 grams Potassium bromide 0O34 grams Potassium carbonate 32 grams Hydroxylamine sulfate 2~0 grams Water to make one liter "
25 ~ Di-p-toluenesulfonic acid salt of N-ethyl-N-methoxyethyl-3-methyl-p-phenylenediamine .

~20-~. .

5~763 Sequestering agents were incor.porated in samples of' this developer composition as described in Table V belowO
To certain of the samples lithium sulfate was added in the amount indicated in Table V and to certain of the samples ferrous chloride was added in an amount suf'ficient to give a concen-tration of ferrous ion as indi.cated in Table VO One-half of each sample was stored in a closed bottle while the other half was stored in an open lOOO~milliliter graduated cylinder. Both the open and closed samples were analy~ed for ammonia generation over a period of two monthsO

~L~5576 _ o 0 ~ O r~
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Q t~
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~: ~ o ~ o ~ ~ ~ ~ o ~ 5 o ~i C~ o _ S: N
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_ ~ ~

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o a~ ~ o o o o o o o o ,D oo r~
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. :. :' .
o Z r~ N(r) ~ L~~O ~ 0 r~i N
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~ I~' ' ~55~7~i3 Results of the tests for ammonia generation in the open samples are given in Table VI below, in which the values reported represent the concentration of ammonia in the developer solution measured in milligrams per liter at the speci~ied number of days from the start of the test~

TABLE VI

Test Days From Start of Test No. 0 3 7 14 _ 35 49 4 68 6 6 7 8 6 l~

6 34 4 3 4 `4 -- 3

7 215 19 37 47 79 68 55

8 23 5 4 4 4 6 6 Results of the tests for ammonia generation in the closed samples are given in Table VII below3 in which the values reported represent the concentration of ammonia in the developer solution measured in milligrams per liter at :~
the specified number of days from the start of the test~

TABLE VII
Test Dayl4From Sta35 of Tes4 ~ _ __ ,~. _.

6 4 7 8 10 :

- ~ ~

3~557~i3 The data in Tables V, v~r and VII show that when both the sequestering agent 1~3-diamino-2-propanol tetraac.eti..c ac,i.d and the sequestering agent l-hydroxyethylidene-1.3 l~diphosphon:ic acid are added to the color developing solution in effective amounts the evolution of ammonia is suppressed whether or not iron is present in the solution, The data al.so show that it is not necessary to include a lithium salt in a developer containing both 1,3-diamino-2-propanol tetraacetic acid and l-hydrox~Jethylidene-l, l-diphosphonic acid~
10The invention has been described in detail with particular reference to preferred embodiments thereof3 but it will be understood that variations and modifications can be effected within the spirit and scope of the invention~ --24~

Claims (18)

What Is Claimed Is:

1. A sequestering composition for use in stabil-izing a photographic color developer containing a primary aromatic amino color developing agent and an hydroxylamine salt, said composition comprising 1,3-diamino-2-propanol tetraacetic acid and a diphosphonic acid sequestering agent, said 1,3-diamino-2-propanol tetraacetic acid and diphosphonic acid sequestering agent being present in said composition in an amount sufficient to stabilize said photographic color developer.

2. A composition as claimed in claim 1 wherein said diphosphonic acid sequestering agent is an hydroxyalkylidene diphosphonic acid sequestering agent.

3 A composition as claimed in claim 1 wherein said diphosphonic acid sequestering agent has the formula:

wherein R2 is alkyl of 1 to 5 carbon atoms.

4. A composition as claimed in claim 1 wherein said diphosphonic acid sequestering agent is 1-hydroxyethyl-idene-1, 1-diphosphonic acid.

5. A photographic color developer composition containing (1) a primary aromatic amino color developing agent, (2) an hydroxylamine salt, (3) 1,3-diamino-2-propanol tetraacetic acid, and (4) a diphosphonic acid sequestering agent, said 1,3-diamino-2-propanol tetraacetic acid and diphosphonic acid sequestering agent being present in said photographic color developer composition in a stabilizing amount.

6. A composition as claimed in claim 5 wherein said primary aromatic amino color developing agent is a p-phenylene-diamine.

7. A composition as claimed in claim 5 wherein said primary aromatic amino color developing agent is 4-amino-N-ethyl-N-(.beta.-methanesulfonamidoethyl)-m-toluidine sesquisulfate monohydrate.

8. A composition as claimed in claim 5 wherein said primary aromatic amino color developing agent is the di-p-toluenesulfonic acid salt of N-ethyl-N-methoxyethyl-3-methyl-p-phenylenediamine.

9. A composition as claimed in claim 5 wherein said hydroxylamine salt is hydroxylamine sulfate.

10. A composition as claimed in claim 5 wherein said diphosphonic acid sequestering agent is an hydroxyalkylidene diphosphonic acid sequestering agent.

11. A composition as claimed in claim 5 wherein said diphosphonic acid sequestering agent has the formula:

wherein R2 is alkyl of 1 to 5 carbon atoms.

12. A composition as claimed in claim 5 wherein said diphosphonic acid sequestering agent is 1-hydroxyethylidene-1, 1-diphosphonic acid.

13. An aqueous photographic color developer solution containing (1) a primary aromatic amino color developing agent, (2) an hydroxylamine salt, (3) 1,3-diamino-2-propanol tetraacetic acid in an amount of from about 0.005 to about 0.1 moles per liter of solution, and (4) a diphosphonic acid sequestering agent in an amount of from about 0.0005 to about 0.001 moles per liter of solution.

14. An aqueous photographic color developer solution containing (1) 4-amino-N-ethyl-N-(.beta.-methanesulfonamido-ethyl)-m-toluidine sesquisulfate monohydrate, (2) hydroxylamine sulfate, (3) 1,3-diamino-2-propanol tetraacetic acid in an amount of from about 0.005 to about 0.1 moles per liter of solution, and (4) 1-hydroxyethylidene-1, 1-diphosphonic acid in an amount of from about 0.0005 to about 0.001 moles per liter of solution.

15. A method of decreasing the tendency for ammonia generation to occur in an aqueous photographic color developer solution containing a primary aromatic amino color developing agent and an hydroxylamine salt as a result of decomposition of said hydroxylamine salt, which method comprises incorpor-ating in said developer solution an effective amount of both 1,3-diamino-2-propanol tetraacetic acid and a diphosphonic acid sequestering agent.

16. A method as claimed in claim 15 wherein the amount of said 1,3-diamino-2-propanol tetraacetic acid is from about 0.005 to about 0.1 moles per liter of developer solution and the amount of said diphosphonic acid sequestering agent is from about 0.0002 to about 0.001 moles per liter of developer solution.

17. A method as claimed in claim 15 wherein said diphosphonic acid seqestering agent has the formual:

wherein R2 is alkyl of 1 to 5 carbon atoms.

18. A method as claimed in claim 15 wherein said diphosphonic acid sequestering agent is 1-hydroxyethylidene-1, 1-diphosphonic acid.