Photographic reversal composition and method of use

Color reversal photographic films are processed using a reversal solution comprising stannous ion and a quaternary ammonium compound as the sole biocide, to reduce formation of biogrowth. The quaternary ammonium compound is present at very low concentrations of 1 to 20 ppm, and is preferably myristyltrimethyl ammonium bromide because it avoids precipitates with components that leach out of processed films.

FIELD OF THE INVENTION 
This invention relates in general to color photography and in particular, 
to a photographic reversal composition and a method of processing color 
reversal photographic elements. More particularly, the invention relates 
to an improved reversal composition that has improved antimicrobial agents 
at low concentration and to a method for its use. 
BACKGROUND OF THE INVENTION 
Multicolor, multilayer photographic elements are well known in the art. 
Such materials generally have three different selectively sensitized 
silver halide emulsion layers coated on one side of a single support. Each 
layer has components useful for forming a particular color in an image. 
Typically, the materials utilize color forming couplers or dyes in the 
sensitized layers during processing. 
One commercially important process intended for use with color reversal 
photographic films useful for providing positive color images, can include 
the following sequence of steps: first (or black-and-white) development, 
washing, reversal reexposure, color development, bleaching, fixing, and 
washing and/or stabilizing. Another useful process is similar but includes 
stabilizing between color development and bleaching. Such conventional 
steps are described, for example, in U.S. Pat. No. 4,921,779 (Cullinan et 
al), U.S. Pat. No. 4,975,356 (Cullinan et al), U.S. Pat. No. 5,037,725 
(Cullinan et al), U.S. Pat. No. 5,523,195 (Darmon et al) and U.S. Pat. No. 
5,552,264 (Cullinan et al). 
Thus, it is known that after the first development, the exposed films are 
subjected to a reversal reexposure and subsequent color development. 
Certain nucleating agents have been used in a solution applied after the 
first development in place of reversal reexposure. Such a solution is 
known as a "reversal bath". Very early reversal baths contained certain 
boron compounds as nucleating agents, but they had a number of 
disadvantages that led to improvements with the use of stannous salts that 
are stable in both acidic and alkaline environments. 
The nucleating agents in the reversal bath are intended to reduce silver 
ion remaining undeveloped from the first development step. Commercial 
reversal baths generally contain stannous ion as the silver ion reducing 
agent, as described for example, in U.S. Pat. No. 3,617,282 (Bard et al). 
Stannous ion is generally provided in the form of a simple or chelated 
salt. 
Commercial reversal bath solutions, however, can exhibit a number of 
problems. They may give off an unpleasant odor due to the presence of 
volatile organic acids typically used as buffers, and undesirable 
biogrowth may occur in the processing tank. In addition, reversal bath 
solutions may require filtration after certain hours of use because of the 
build-up of predominately organic precipitates from high biological 
matter. Reduction of such biogrowth is a considerable challenge in the 
art. This would reduce the need for filtration, filter changes and other 
costly maintenance. 
The microbial population in most commercial "seasoned" or used reversal 
bath solutions is commonly on the order of 10.sup.4 to 10.sup.5 CFU/ml 
(colony forming units/ml). This causes customer dissatisfaction because of 
the need for more frequent solution replacement and processor tank 
cleaning. Thus, there is a need to reduce this level of bacterial and 
fungal organisms in such solutions. 
Although there are many known anti-microbial compounds, in order to use 
them effectively in photographic processing solutions, interactions with 
components of the processed photographic materials must be avoided. In 
addition, the anti-microbial compounds must not interact with other 
components of the processing solutions. 
Previous attempts to solve this problem are described in U.S. Pat. No. 
5,811,225 (McGuckin et al) in which various quaternary ammonium compounds 
were used as anti-microbials at 50-150 ppm. The preferred anti-microbial 
compound in those embodiments was myristyltrimethyl ammonium bromide 
(MTAB). However, when MTAB or other described anti-microbial compounds 
were used at the noted concentrations, they tended to react with 
components (for example, certain filter dyes) that leach out of the 
processed color reversal films. One reaction product produced is a bright 
pink precipitate that is unacceptable to customers, requiring costly 
maintenance and frequent solution replacement. 
First of all, there is a need for a low cost reversal bath composition that 
is not susceptible to the problems noted above (for example biogrowth), 
and which continues to have the desirable photochemical properties 
obtained from the use of stannous ion. Preferably, there is a need for a 
reversal bath composition that does not contain any precipitates from 
reaction of the anti-microbial compounds with process film components. 
SUMMARY OF THE INVENTION 
A low cost and microbe-free photographic reversal composition comprises 
stannous ion at a concentration of from about 0.002 to about 0.02 mol/l, 
and a quaternary ammonium compound as the sole biocide at a concentration 
of from about 1 to about 20 ppm, the quaternary ammonium compound having a 
molecular weight of from about 175 to about 440. 
In a preferred embodiment, this composition comprises myristyltrimethyl 
ammonium bromide (MTAB) as the sole biocide at the concentration of from 
about 1 to about 20 ppm. 
This invention also provides a method of processing a color reversal 
photographic element comprising: 
A) contacting an imagewise exposed, black-and-white developed, color 
reversal photographic element with any of reversal compositions noted 
above, and 
B) color developing the element. 
The reversal composition of this invention exhibits reduced biogrowth (both 
fungal and bacterial) after lengthy use in the reversal bath tank, and 
this advantage is achieved by including in the composition a specific 
quaternary ammonium compound as the only biocide. Generally, this material 
is soluble in solution and does not form complexes with salts in the 
composition. It is highly compatible with the other essential components 
of the reversal bath composition, particularly in concentrated form. Thus, 
biogrowth is reduced without sacrificing photographic quality in the 
processed element. 
In addition, the composition comprises the quaternary ammonium biocide at 
much lower concentration (from about 1 to about 20 ppm) than previously 
used or described in U.S. Pat. No. 5,811,225 (noted above). Thus, the 
precipitates formed at the higher concentrations are avoided, and costs 
are reduced with the use of less biocide. 
In a highly preferred embodiment, the biocide is MTAB at from about 1 to 
about 20 ppm because it not only inhibits biogrowth but avoids 
precipitates with components that leach out of the processed element. 
Thus, the bright pink precipitates noted above are avoided with the use of 
MTAB at these low concentrations. 
DETAILED DESCRIPTION OF THE INVENTION 
A wide variety of color reversal photographic elements can be used in the 
practice of the present invention. A detailed description of such 
materials is found, for example, in Research Disclosure, publication 
36544, pages 501-541 (September 1994). Research Disclosure is a 
publication of Kenneth Mason Publications Ltd., Dudley House, 12 North 
Street, Emsworth, Hampshire PO10 7DQ England (also available from Emsworth 
Design Inc., 121 West 19th Street, New York, N.Y. 10011). This reference 
will be referred to hereinafter as "Research Disclosure". More details 
about such elements are provided herein below. Such elements are generally 
used to provide color positive images in what are known as color reversal 
films and papers. 
Color reversal photographic elements utilized in the practice of this 
invention are comprised of a support having on one side thereof a 
plurality of photosensitive silver halide emulsion layers. The 
photosensitive layers can contain any of the conventional silver halides 
as the photosensitive material, for example, silver chloride, silver 
bromide, silver bromoiodidc, silver chlorobromide, silver chloroiodide, 
silver chlorobromoiodide, and mixtures thereof. Useful support materials 
include cellulose acetate film, polyvinylacetal film, polycarbonate film, 
polystyrene film, polyethylene terephthalate film, and the like. The 
silver halide is dispersed within a suitable hydrophilic colloid such as 
gelatin or derivatives thereof. The silver halide emulsion layers can 
contain a variety of well-known addenda, including but not limited to, 
chemical sensitizers, development modifiers and antifoggants. 
Some specific commercially available color reversal photographic films that 
can be used in the practice of the present invention include, but are not 
limited to, EKTACHROME and KODACHROME Color Reversal Films (Eastman Kodak 
Company), FUJICHROME Color Reversal Films (Fuji Photo Film Co., Ltd.), 
AGFACHROME Color Reversal Films (AGFA), KONICACHROME Color Reversal Films 
(Konica) and SCOTCHCHROME Color Reversal Films (Imation). 
Color reversal films particularly useful in the practice of this invention 
include those containing what are known in the art as arylpyrazolone type 
magenta dye forming color couplers. Such color couplers are well known in 
the art, as described for example in U.S. Pat. No. 5,037,725 (Cullinan et 
al). 
As explained above, color reversal processes of the prior art utilize a 
first developer bath, a reversal bath, a color developer bath, a 
conditioning bath, a bleaching bath, a fixing bath and a stabilizing bath. 
The components that are useful in each of such baths are well known in the 
photographic art. The improved process of this invention can utilize the 
same baths except that the improved reversal composition of this invention 
is used instead of the conventional reversal bath solutions. 
Any processing sequence can be used for the processing the color reversal 
elements. For example, two conventional processing methods are known as 
Process E-6 and Process K-14 for color reversal films. 
The first developer generally contains a black-and-white developing agent 
or a mixture thereof. Useful developing agents include, but are not 
limited to, dihydroxybenzene developing agents (such as hydroquinone), 
3-pyrazolidone developing agents (such as 1-phenyl-3-pyrazolidone), 
ascorbic acid or derivatives thereof, and aminophenol developing agents 
(such as p-aminophenol). Mixtures of various developing agents can be used 
to advantage as well. In addition to the developing agent, the first 
developer typically contains other agents such as preservatives, metal ion 
sequestering agents, anti-sludging agents, stabilizing agents, 
contrast-promoting agents, restrainers, halides, hydroxides, antifoggants, 
buffers and silver halide solvents. Examples of useful black-and-white 
developing compositions are described in U.S. Pat. No. 5,187,050 (Yamada 
et al), U.S. Pat. No. 5,683,859 (Nothnagle et al) and U.S. Pat. No. 
5,702,875 (Opitz et al), all incorporated herein by reference. 
The reversal composition of this invention is used following the first 
development step. A critical component is a nucleating agent such as 
stannous ions that are generally provided in the form of stannous salts or 
chelated stannous salts, as described for example in U.S. Pat. No. 
3,617,282 (noted above), incorporated herein by reference. Particularly 
useful stannous salts include, but are not limited to, stannous chloride, 
stannous bromide, stannous fluoride and stannous acetate. Stannous 
chloride is preferred. 
Stannous ions are generally present in the composition in an amount 
sufficient to provide the reversal exposure needed after the first 
development. The concentration can be at least 0.002 mol/l, and generally 
does not exceed about 0.02 mol/l. Preferably, the stannous ion 
concentration is from about 0.004 to about 0.01 mol/l. Sources of stannous 
ions can be readily purchased from a number of commercial sources. 
A second critical component of the reversal composition of this invention 
is a quaternary ammonium compound that is used as the sole biocide. Such 
materials have one or more quaternary nitrogen atoms in the molecule, and 
generally have a molecular weight of at least about 175 and less than 
about 440. Preferably, the molecular weight is from about 250 to about 
420, and more preferably it is from about 300 to about 380. 
Each quaternary nitrogen atom in the molecule has its four valences filled 
with nonpolymeric aliphatic, heterocyclic or carbocyclic groups. 
As used herein, "aliphatic" refers to a monovalent organic radical having 1 
to 30 carbon atoms in the backbone that can be interrupted with one or 
more oxy, thio, imino or carbonyl groups. Hydrogen atoms along the 
backbone can be replaced with fluorine atoms to provide fluorinated 
aliphatic groups. The aliphatic groups can be substituted with one or more 
halo atoms, aryl, alkoxy, amino, cycloalkyl or other groups as would be 
readily apparent to one skilled in the art. 
As used herein, the term "heterocyclic" refers to a monovalent organic 
radical having at least one heterocyclic moiety in the backbone containing 
one or more oxygen, nitrogen or sulfur atoms. In addition, the 
heterocyclic group can include a quaternary ammonium group. The 
heterocyclic group can be aromatic or nonaromatic and generally includes 
up to 15 atoms in the mono- or polycyclic ring or nucleus that can be 
substituted with one or more other organic groups if desired as would be 
readily apparent to one skilled in the art. 
The term "carbocyclic" refers to an organic monovalent radical that has all 
carbon atoms in a mono- or polycyclic ring or nucleus, including 
cycloalkyl, cycloalkenyl and aryl groups. Such rings generally have up to 
14 carbon atoms in the ring structure which can be substituted with one or 
more other organic groups as would be readily apparent to one skilled in 
the art. 
Useful quaternary ammonium compounds that are biocides for this invention 
can also be represented by the formula III: 
EQU R.sub.5 (R.sub.6)N.sup.+ (R.sub.7)R.sub.8 X.sup.- 
wherein R.sub.5, R.sub.6, R.sub.7 and R.sub.8 are independently 
nonpolymeric aliphatic, heterocyclic or carbocyclic radicals as defined 
above. X.sup.- is defined below. Preferably, each of the radicals is a 
monovalent heterocyclic or alkyl group, and the sum of the carbon and 
hetero atoms in the chains of all four groups is at least 10 and generally 
less than 20. Most preferably, at least one of the radicals has a chain 
length of at least 8 carbons, and up to 18 carbons, which can be 
interrupted with one or more nitrogen or oxygen atoms. 
Alternatively, any two or three of the radicals of the noted structure can 
form a quaternary ring with the nitrogen atom, such as a pyridinium, 
piperidinium, pyrazinium, quinolinium or morpholino ring. 
Particularly useful biocides are those having quaternary nitrogens having 
its four valences filled with the same or different hydrocarbon groups 
having 1 to 20 carbon atoms as long as these are at least 10 carbon atoms 
for at least one group. Preferably, one or two of the hydrocarbon groups 
have 1 to 3 carbon atoms, and the remaining hydrocarbon groups are 
considerably larger, for example having at least 8 carbon atoms. More 
preferably, one of the groups has at least 12 carbon atoms, and each of 
the remaining groups has only 1 or 2 carbon atoms. 
The anions (X.sup.-) for the cationic compounds can be any suitable 
negatively charged monovalent ion such as a halide or anions of small 
organic or inorganic salts, such as acetates, that does not form a 
precipitate in solution or otherwise deleteriously affects the action of 
the reversal solution. Halides, such as chloride and bromide, are 
preferred. 
Representative biocides useful in this invention include, but are not 
limited to, nonyltrimethyl ammonium bromide, dodecyltrimethyl ammonium 
chloride, hexadecyltrimethyl ammonium bromide (or cetyltrimethyl ammonium 
bromide), hexadecyltrimethyl ammonium chloride (or cetyltrimethyl ammonium 
chloride), benzyltriethyl amnionium chloride, didodecyldimethyl ammonium 
bromide, benzyldimethylphenyl ammonium chloride, tetrahexyl ammonium 
chloride, stearyldimethylbenzyl ammonium chloride, cetylpyridinium 
chloride, benzalkonium chloride (a mixture of alkyldimethylbenzyl ammonium 
chlorides), a mixture of alkyltrimethyl ammonium bromides (also known as 
"Cetrimide"), and myristyltrimethyl ammonium bromide. Mixtures of such 
compounds can be used if desired since many of them are commercially 
available as mixtures. A most preferred compound is myristyltrimethyl 
ammonium bromide because it is not only an excellent biocide, but its use 
results in less formation of precipitates in the processing bath. 
Many of these compounds are available from a number of commercial sources, 
including Lonza Chemicals or Zeeland Chemicals Inc. They may be supplied 
as pure compounds, aqueous solutions or as aqueous mixtures. 
One compound not useful in the present invention is known as Hyamine 1622, 
benzethonium chloride, or 
(benzyldimethyl-2-{2-[4-(1,1,3,3-tetramethylbutyl)phenoxy]ethoxy}ethylammo 
nium chloride. Its molecular weight is too high (about 448) and has been 
observed to result in cloudy solutions and precipitates in concentrated 
reversal solutions. 
The quaternary ammonium compound useful in the practice of this invention 
is generally present in a concentration of from about 1 to about 20 ppm 
and preferably from about 1 to about 10 ppm, and more preferably from 
about 5 to about 10 ppm. The particular amount of a given compound used in 
the reversal bath composition will depend upon its solubility and other 
factors. If the compounds have high solubility, the useful concentration 
may be higher, and the concentration may be even higher if the solution is 
formulated, stored or used in a concentrated form, as described in U.S. 
Pat. No. 5,736,302 (Buongiorne et al). 
The reversal composition can also include other conventional components 
such as buffers and sequestering agents, or mixtures thereof. Useful 
sequestering agents include various known aminocarboxylic acids or 
aminopolyphosphonic acids or salts thereof. 
It may be desirable for the reversal composition to include one or more 
stannous ion stabilizers as are known in the art. Useful stabilizers 
include, but are not limited to, p-aminophenol, phenylenediamine and 
Bandrowski's base. Such stabilizers are present in conventional amounts, 
that is generally at least about 0.1 mg/l and preferably from about 0.2 to 
about 0.8 mg/l. p-Aminophenol is preferred. 
It is particularly useful for the reversal composition to contain one or 
more organic phosphonic or phosphinic acid chelating agents. Such 
chelating agents can be generally represented by the structure I or II: 
EQU R.sub.1 N(CH.sub.2 PO.sub.n M.sub.2).sub.2 (I) 
or 
EQU R.sub.2 R.sub.3 C(PO.sub.n M.sub.2).sub.2 (II) 
wherein n is 2 or 3, and preferably 3. 
R.sub.1 is hydrogen, a substituted or unsubstituted alkyl group of 1 to 12 
carbon atoms (such as methyl, hydroxymethyl, ethyl, isopropyl, t-butyl, 
hexyl, octyl, nonyl, decyl, benzyl, 4-methoxybenzyl, phenethyl or 
o-octamidobenzyl), a substituted or unsubstituted alkylaminoalkyl group 
(wherein the alkyl portion of the group is an defined above, such as 
methylaminomethyl or ethylaminoethyl), a substituted or unsubstituted 
alkoxyalkyl group of 1 to 12 carbon atoms (such as methoxymethyl, 
methoxyethyl, propoxyethyl, benzyloxy, methoxymethylenemethoxymethyl, or 
t-butoxy), a substituted or unsubstituted cycloalkyl group of 5 to 10 
carbon atoms (such as cyclopentyl, cyclohexyl, cyclooctyl or 
4-methylcyclohexyl), a substituted or unsubstituted aryl group of 6 to 10 
carbon atoms (such as phenyl, xylyl, tolyl, naphthyl, p-methoxyphenyl or 
4-hydroxyphenyl), or a substituted or unsubstituted 5- to 10-membered 
heterocyclic group having one or more nitrogen, oxygen or sulfur atoms in 
the ring besides carbon atoms [such as pyridyl, pyrimidyl, 
pyrrolyldimethyl, pyrrolyldibutyl, benzothiazolylmethyl, 
tetrahydroquinolylmethyl, 2-pyridinylmethyl, 4-(N-pyrrolidino)butyl or 
2-(N-morpholino)ethyl]. 
R.sub.2 is hydrogen, a substituted or unsubstituted alkyl group of 1 to 12 
carbon atoms (as defined above), a substituted or unsubstituted aryl group 
of 6 to 10 carbon atoms (as defined above), a substituted or unsubstituted 
cycloalkyl group of 5 to 10 carbon atoms (as defined above), a substituted 
or unsubstituted 5- to 10-membered heterocyclic group (as defined above), 
--PO.sub.n M.sub.2 or --CHR.sub.4 PO.sub.n M.sub.2. 
R.sub.3 and R.sub.4 are independently hydrogen, hydroxyl, a substituted or 
unsubstituted alkyl group of 1 to 12 carbon atoms (as defined above) or 
--PO.sub.n M.sub.2. 
M is hydrogen or a water-soluble monovalent cation imparting 
water-solubility such as an alkali metal ion (for example sodium or 
potassium), or ammonium, pyridinium, triethanolammonium, triethylammonium 
ion or others readily apparent to one skilled in the art. The two cations 
in each molecule do not have to be the same. Preferably, M is hydrogen, 
sodium or potassium. 
In defining the substituted monovalent groups herein, useful substituents 
include, but are not limited to, an alkyl group, hydroxy, sulfo, 
carbonamido, sulfonamido, sulfamoyl, sulfonato, thioalkyl, 
alkylcarbonamido, alkylcarbamoyl, alkylsulfonamido, alkylsulfamoyl, 
carboxyl, amino, halo (such as chloro or bromo) sulfono, or sulfoxo, 
alkoxy of 1 to 5 carbon atoms (linear or branched), --PO.sub.n M.sub.2, 
--CH.sub.2 PO.sub.n M.sub.2 or --N(CH.sub.2 PO.sub.n M.sub.).sub.2 wherein 
the alkyl (linear or branched) for any of these groups has 1 to 5 carbon 
atoms. 
Representative phosphonic acids useful in the practice of this invention 
include, but are not limited to the compounds listed in EP 0 428 101 A1 
(page 4). Representative useful compounds are 
1-hydroxyethylidene-1,1-diphosphonic acid, 
diethylenetriaminepentaphosphonic acid, 
ethylenediamine-N,N,N',N'-tetramethylenephosphonic acid, 
nitrilo-N,N,N-trimethylenephosphonic acid [also known as 
aminotris(methylenephosphonic acid)], 
1,2-cyclohexanediamine-N,N,N',N'-tetramethylenephosphonic acid, 
o-carboxyaniline-N,N-dimethylenephosphonic acid, 
propylamine-N,N-dimethylenephosphonic acid, 
4-(N-pyrrolidino)butylamine-N,N-bis(methylenephosphonic acid), 
1,3-diamino-2-propanol-N,N,N',N'-tetramethylenephosphonic acid, 
1,3-propanediamine-N,N,N', N'-tetramethylenephosphonic acid, 
1,6-hexanediamine-N,N,N',N'-tetramethylenephosphonic acid, 
o-acetamidobenzylamine-N,N-dimethylenephosphonic acid, 
o-toluidine-N,N-dimethylenephosphonic acid, 
2-pyridinylmethylamine-N,N-dimethylenephosphonic acid, 1-hydroxyethane- 
1,1-diphosphonic acid, 
diethylenetriamine-N,N,N',N",N"-penta(methylenephosphonic acid), 
1-hydroxy-2-phenylethane- 1,1-diphosphonic acid, 2-hydroxyethane- 
1,1-diphosphonic acid, 1-hydroxyethane-1,1,2-triphosphonic acid, 
2-hydroxyethane-1,1,2-triphosphonic acid, ethane-1,1-diphosphonic acid, 
and ethane-1,2-diphosphonic acid, amino tris(methylenephosphonic acid), or 
salts thereof. 
Particularly useful are 1-hydroxyethylidene-1,1-diphosphonic acid, 
aminotris(methylenephosphonic acid), 
diethylenetriamine-N,N,N',N",N"-penta(methylenephosphonic acid), or salts 
thereof. The second compound is most useful. 
One or more of the phosphonic or phosphinic acids defined above are present 
in conventional amounts, and generally in an amount of at least about 2 
g/l. 
It is particularly desirable that the reversal composition have a pH of 
from about 4 to about 8, and preferably at from about 5 to about 7, when 
in the form of an aqueous solution. This can be achieved in suitable 
chemical acids or bases, or buffers, as needed. 
The composition of this invention may be formulated in solid form such as a 
powder, pellets, tablet and the like that upon dissolution provides the 
composition of this invention. 
Conventional color developing solutions can be used in the practice of this 
invention. In addition to an aromatic primary amino color developing 
agent, the color developing bath typically contains sequestering agents, 
buffering agents, preservatives, competing couplers and silver halide 
solvents that are commonly used in the industry for this purpose. Examples 
and amounts of such conventional compositions and components are described 
for example in U.S. Pat. No. 5,037,725 (Cullinan et al) and U.S. Pat. No. 
5,552,264 (Cullinan et al), both incorporated by reference. 
Particularly useful aromatic primary 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 useful p-phenylenediamine color developing 
agents include but are not limited to: N,N-diethyl-p-phenylenediamine 
monohydrochloride 4-N,N-diethyl-2-methylphenylene-diamine 
monohydrochloride, 
4-(N-ethyl-N-2-methane-sulfonylaminoethyl)-2-methylphenylenediamine 
sesquisulfate monohydrate, 
4-(N-ethyl-N-2-hydroxyethyl)-2-methyl-phenylenediamine sulfate, 
4-N,N-diethyl-2,2'-methanesulfonylamino-ethyl-phenylenediamine 
hydrochloride, and others readily apparent to a skilled worker in the art. 
Conventional pre-bleach or conditioning solutions can be used in the 
practice of the present invention, as described for example in U.S. Pat. 
No. 4,839,262 (Schwartz), U.S. Pat. No. 4,921,779 (Cullinan et al), U.S. 
Pat. No. 5,037,725 (Cullinan et al), U.S. Pat. No. 5,523,195 (Darmon et 
al), U.S. Pat. No. 5,552,264 (Cullinan et al), all incorporated herein by 
reference. Preferred conditioning solutions include aliphatic thiol bleach 
accelerating agents, formaldehyde precursors (such as sodium fonnaldehyde 
bisulfite or hexamethylenetetraamine), secondary amines, sulfites as 
preservatives, buffering agents, and metal ion sequestering agents. 
The essential component of a bleaching bath useful in this invention is a 
bleaching agent that converts metallic silver to silver ions. Other common 
components of the bleaching bath include halides, metal ion sequestering 
agents, optical brighteners, preservatives, biocides, antioxidants, 
anti-fungal agents, anti-foam agents, buffers and corrosion inhibitors. 
Ammonium or alkali metal salts of a ferric complex of an 
aminopolycarboxylic acid are particularly useful as bleaching agents but 
other metal complexes are known in the art, including binary and ternary 
complexes. Also of utility are the persulfate bleaching agents such as 
ammonium or alkali metal persulfates and peroxide bleaching agents. 
Bleaching agents can be used individually or in the form of mixtures of 
two or more bleaching agents. Examples of biodegradable bleaching agents 
include those described in U.S. Pat. No. 5,670,305 (Gordon et al) and in 
U.S. Ser. No. 09/283,396 (Price) filed Apr. 1, 1999. Such bleaching agents 
include iron complexes of one or more biodegradable chelating ligands 
including alkyliminodiacetic acids, aminodisuccinic acids, 
aminomonosuccinic acids, alaninediacetic acid, pyridinecarboxylic acids, 
pyridinedicarboxylic acids, nitrilotriacetic acid, glycinesuccinic acid 
and 2-pyridylmethyliminodiacetic acid. 
A fixing solution converts all silver halide into soluble silver complexes 
that diffuse out of the emulsion layers. Fixing solution retained within 
the layers of the photographic element is removed in a subsequent water 
washing step. Thiosulfates, including ammonium thiosulfate and alkali 
metal thiosulfates (such as sodium thiosulfate and potassium thiosulfate), 
are particularly useful as fixing agents. Other components of the fixing 
solution include preservatives, fixing accelerators, buffers and metal ion 
sequestering agents. Further details of useful fixing solutions are 
described in the art, including the Cullinan et al patents noted above. It 
may also be useful to include one or more uncomplexed aminodisuccinic 
acids in the fixing solution as described in U.S. Ser. No. 09/283,396 of 
Price noted above. 
Bleach-fixing solutions may be useful in the process of this invention. 
Such solutions are well known in the art and generally include one or more 
components of the bleaching and fixing solutions described above. 
A final rinse composition can be used in the process as a final processing 
bath. Such compositions can include one or more surfactants (anionic, 
nonionic or both), biocides, metal chelating agents, buffers and other 
components known in the art, as described for example in U.S. Pat. No. 
3,545,970 (Giorgianni et al), U.S. Pat. No. 5,534,396 (McGuckin et al), 
U.S. Pat. No. 5,645,980 (McGuckin et al), U.S. Pat. No. 5,667,948 
(McGuckin et al) and U.S. Pat. No. 5,716,765 (McGuckin et al), all of 
which are incorporated herein by reference. 
A wide variety of different color reversal processes are well known in the 
art. For example, a single color developing step can be used when the 
coupling agents are incorporated in the photographic element or three 
separate color developing steps can be used in which coupling agents are 
included in the developing solutions. In order to provide shorter 
processing times, bleaching and fixing can be combined in a single step 
(bleach-fixing step). 
The photographic elements processed in the practice of this invention can 
be single or multilayer color elements. Multilayer color elements 
typically contain dye image-forming units sensitive to each of the three 
primary regions of the visible spectrum. Each unit can be comprised of a 
single emulsion layer or multiple emulsion layers sensitive to a given 
region of the spectrum. The layers of the element can be arranged in any 
of the various orders known in the art. In an alternative format, the 
emulsions sensitive to each of the three primary regions of the spectrum 
can be disposed as a single segmented layer. The elements can also contain 
other conventional layers such as filter layers, interlayers, subbing 
layers, overcoats and other layers readily apparent to one skilled in the 
art. A magnetic backing can be used as well as conventional supports. 
The color reversal elements are typically exposed to suitable radiation to 
form a latent image and then processed as described above to form a 
visible positive color image. 
The conditions (time and temperature) for the various steps of the method 
of this invention are well known in the art. The reversal step, in 
particular, is carried out for from about 45 to about 200 seconds at a 
temperature of from about 20 to about 40.degree. C. Times and temperatures 
outside these ranges can be used if desired. 
Processing according to the present invention can be carried out using 
conventional deep tanks holding processing solutions. The tanks or stages 
can be arranged in countercurrent or concurrent flow. Alternatively, it 
can be carried out using what is known in the art as "low volume thin 
tank" processing systems having either rack and tank or automatic tray 
designs. Such processing methods and equipment are described, for example, 
in U.S. Pat. No. 5,436,118 (Carli et al) and publications noted therein.

The following examples are provided for illustrative purposes only and are 
not intended to be limiting in any way. Unless otherwise indicated, all 
percentages are by weight. 
EXAMPLES 1-6 
Reversal Solutions with Various Biocides 
Several working strength reversal compositions of this invention were 
prepared as follows: 
A concentrated reversal bath formulation (without biocide) was prepared 
with the following components: 
______________________________________ 
Tap water 840.0 g/l 
DEQUEST 2000* (50%) 125.36 g/l 
Sodium hydroxide (50%) 78.0 g/l 
Stannous chloride, anhydrous 33.0 g/l 
p-Aminophenol 0.01 g/l 
To provide 1 liter of solution. 
______________________________________ 
*DEQUEST 2000 is a 50% (by weight) solution of 
aminotris(methylenephosphonic acid) available from Monsanto Co. 
The concentrated solution was diluted to a working strength solution with 
tap water (19:1), and 200 ml aliquots were distributed into glass jars. 
The biocide being evaluated (at various concentrations) was added to a 
given jar along with 2 ml of an inoculum comprised of "seasoned" reversal 
bath solution from a commercial Hope 296 processing machine. The microbial 
concentration (various bacterial and fungal organisms) of the inoculum was 
at least about 10.sup.6 CFU/ml. Upon addition to the cups, the inoculum 
microbial concentration was thusly diluted 100:1 (to 10.sup.4 CFU/ml). 
Each jar and solution was incubated at 30.degree. C., and samples were 
taken from each jar after 7 days. The levels of biogrowth were determined 
visually. 
The following quaternary ammonium compounds were evaluated as the sole 
biocides in the samples noted above. 
Example 1: Myristyltrimethyl ammonium bromide (MTAB). 
Example 2: Benzalkonium chloride (commercial mixture of alkyldimethylbenzyl 
ammonium chlorides). 
Example 3: Cetylpyridinium chloride ("CPC"). 
Example 4: Cetyltrimethyl ammonium bromide ("CTAB"). 
Example 5: Cetyldimethylethyl ammonium bromide ("CDEAB"). 
Example 6: Commercial mixture of alkyltrimethyl ammonium bromides ("ATAB", 
available as "Cetrimide"). 
TABLE I below lists the results of microbial counts for the samples after 7 
days incubation. 
TABLE I 
__________________________________________________________________________ 
AMOUNT OF 
7 DAY 
SOLUTION BIOCIDE (ppm) BIOGROWTH COMMENTS 
__________________________________________________________________________ 
Control 
0 Significant growth 
no precipitate 
Example 1 1 Moderate growth no precipitate 
Example 1 2 Some growth no precipitate 
Example 1 3 Very little growth no precipitate 
Example 1 5 No growth no precipitate 
Example 1 10 No growth no precipitate 
Example 2 5 No growth crystalline material on solution surface 
Example 2 10 No growth crystalline material on 
solution surface 
Example 2 20 No growth crystalline material on solution surface 
Example 3 5 No growth crystalline material on 
solution surface 
Example 3 10 No growth crystalline material on solution surface 
& in solution 
Example 3 20 No growth crystalline material on solution surface 
& in solution 
Example 4 5 No growth crystalline material on solution surface 
Example 4 10 No growth crystalline material on 
solution surface 
Example 4 20 No growth crystalline material on solution surface 
Example 5 5 No growth crystalline material on 
solution surface 
Example 5 10 No growth crystalline material on solution surface 
Example 5 20 No growth crystalline material on 
solution surface 
Example 6 5 No growth crystalline material on solution surface 
Example 6 10 No growth crystalline material on 
solution surface 
Example 6 20 No growth crystalline material on solution surface 
__________________________________________________________________________ 
The results of these experiments showed that all of the quaternary ammonium 
compounds are useful as the sole biocides in reversal bath compositions of 
this invention. However, only myristyltrimethyl ammonium bromide inhibited 
all precipitate formation in addition to inhibiting biogrowth. 
EXAMPLE 7 
Evaluation of Dye Compatability 
As described above, filter dyes may leach into the reversal bath and can 
react with some of the biocides described herein and form an undesirable 
pink precipitate in the bath. 
The reversal bath concentrate and working strength composition of Examples 
1-7 was distributed in 10 ml aliquots to 25 ml vials. The biocide being 
evaluated (at various concentrations) was added to a given vial along with 
about 0.4 ml (10 drops) of a filter dye solution (comprised of 4 g of a 
conventional filter dye* in 100 of 1% potassium carbonate). Each vial was 
observed visually to see if precipitates formed after 1 day. *The filter 
dye was benzoic acid, 
4-{{4-{3-[1-(4-carboxyphenyl)-1,5-dihydro-3-methyl-5-oxo-4H-pyrazol-4-ylid 
ene]-1-propenyl}-5-hydroxy-3-methyl-1H-pyrazol-1-yl}}. 
In addition to the biocides tested in Examples 1-6, cetyltrimethyl ammonium 
chloride (CTAC) was tested in the reversal bath composition (Example 7). 
TABLE II shows the results of these experiments. 
TABLE II 
______________________________________ 
AMOUNT OF 
SOLUTION BIOCIDE (ppm) OBSERVATIONS 
______________________________________ 
Control 0 Clear pink solution 
Example 1 1 Clear pink solution 
Example 1 2 Clear pink solution 
Example 1 3 Clear pink solution 
Example 1 5 Clear pink solution 
Example 1 10 Clear pink solution 
Example 2 5 Pink residue on vial 
Example 2 10 Pink residue on vial 
Example 2 20 Pink residue on vial 
Example 3 5 Pink precipitate in solution 
Example 3 10 Pink precipitate in solution 
Example 3 20 Pink precipitate in solution 
Example 4 5 Pink precipitate in solution 
Example 4 10 Pink precipitate in solution 
Example 4 20 Pink precipitate in solution 
Example 5 5 Pink precipitate in solution 
Example 5 10 Pink precipitate in solution 
Example 5 20 Pink precipitate in solution 
Example 6 5 Pink flocculent material 
Example 6 10 Pink flocculent material 
Example 6 20 Pink precipitate in solution 
Example 7 5 Pink precipitate in solution 
Example 7 10 Pink precipitate in solution 
Example 7 20 Pink precipitate in solution 
______________________________________ 
These experiments demonstrated that the best biocide is MTAB because it 
does not react with the filter dye that may be present in some color 
reversal elements. The other compounds were acceptable as biocides at the 
lower concentrations but did react with the filter dye. 
EXAMPLE 8 
Processing Reversal Color Photographic Film with Preferred Reversal 
Solutions 
"MTAB" (Example 1 above) was incorporated into reversal bath compositions 
as the sole biocide as used in processing various color reversal films. 
The concentrated reversal bath replenisher formulation and working 
strength composition were formulated as follows: 
______________________________________ 
WORKING STRENGTH 
CONCENTRATE 
REPLENISHER REPLENISHER 
COMPONENT SOLUTION SOLUTION (20 x) * 
______________________________________ 
Water 800 ml 600 ml 
DEQUEST 2000 metal 6.25 g 125 g 
sequestering agent 
(50%) 
NaOH (50%) 9.0 g 180 g 
Acetic acid 5.25 g 105 g 
SnCl.sub.2 1.65 g 33 g 
p-Aminophenol 0.0005 g 0.01 g 
MTAB 10 ppm 200 ppm 
Water to make 1 liter 1 liter 
pH 5.45 5.40 
______________________________________ 
* A fresh tank of solution is made by either taking 800 ml of replenisher 
or 40 ml of the concentrated replenisher and diluting it to 1 liter with 
water. 
The seasoning test comprised three consecutive experimental runs. In each 
run of the seasoning test, the processing machine, a commercially 
available Colex Model 7/6 EKTACHROME roller transport processor, was 
thoroughly cleaned and fresh reversal solution was introduced. In the two 
Control runs of the seasoning test, the reversal solution was KODAK 
Reversal Bath and Replenisher, Process E-6. The reversal composition of 
the invention was used in the second experimental run (Invention). 
Each reversal solution was then replenished while processing KODAK 
Professional EKTACHROME E100S Film to four tank turnovers. Additional 
films that were similarly processed included KODAK EKTACHROME Duplicating 
Film 6121, KODAK Professional EKTACHROME E100VS Film, KODAK Professional 
EKTACHROME E200 Film KODAK EKTACHROME 100 Plus Professional Film/EPP, 
KODAK EKTACHROME 64 Professional Film/EPR, AGFACHROME RSX100 Film, FUJI 
VELVIA Film FUJI PROVIA 100 Film and FUJI PROVIA 400 Film. 
One tank turnover refers to the equivalent of replacing one tank volume 
with a combination of solution carried in from the previous processing 
tank and fresh replenisher solution. A fully seasoned processing solution 
requires about 3 tank turnovers. The test was carried out to four tank 
turnovers to maximize the probability for biogrowth. 
Film processing utilized the following conventional reversal ("Process 
E-6"processing protocol at conventional temperatures: 
______________________________________ 
First Development * 
6 minutes 
Water wash 2 minutes 
Reversal solution ** 2 minutes 
Color development *** 6 minutes 
Prebleach **** 2 minutes 
Bleaching $ 6 minutes 
Fixing # 4 minutes 
Water wash 4 minutes 
Final wash ## 1 minute 
Drying 
______________________________________ 
* First Development used conventional KODAK First Developer for Process 
E6. 
** Reversal solution described above. 
*** Color development used conventional KODAK Color Developer for Process 
E6. 
**** Prebleaching using KODAK Prebleach II & Replenisher for Process E6. 
$ Bleaching using conventional KODAK Bleach for Process E6. 
# Fixing used conventional KODAK Fixer for Process E6. 
## Final washing used KODAK Final Rinse for Process E6. 
In the experimental run in which the invention was practiced, the level of 
bacteria was reduced significantly and fungal growth well controlled. In 
the two Control experimental runs, the bacterial counts were not reduced. 
During the processing using the invention, the reversal bath solution 
turned pink in color, but no precipitates were observed in the solution or 
attached to the processor parts. 
The invention has been described in detail with particular reference to 
preferred embodiments thereof, but it will be understood that variations 
and modifications can be effected within the spirit and scope of the 
invention.