USE OF HYDROQUINONE ESTERS AS BLOCKED COMPETING DEVELOPERS FOR COLOR TRANSFER ASSEMBLAGES

UTILISATION D'ESTERS D'HYDROQUINONE COMME REVELATEURS COMPETITIFS BLOQUES POUR LES ASSEMBLAGES DE TRANSFERT DE COULEUR

English Abstract

ABSTRACT OF THE DISCLOSURE
Hydroquinone esters are incorporated in or
behind a timing layer with a high activation energy to
release a competing developer upon contact with a proces-
sing composition.
- 1 -

Claims

WHAT IS CLAIMED IS:
1. In a photographic assemblage comprising:
a) a support having thereon at least one photosensitive
silver halide emulsion layer having associated there-
with a dye image-providing material;
b) a dye image-receiving layer;
c) an alkaline processing composition and means for
discharging same within said assemblage;
d) a neutralizing layer for neutralizing said alkaline
processing composition; and
e) a timing layer disposed between said neutralizing
layer and said photosensitive silver halide emulsion
layer so that said processing composition must first
permeate said timing layer before contacting said
neutralizing layer;
said assemblage containing a silver halide developing agent,
the improvement wherein said assemblage contains a hydro-
quinone ester either in said timing layer or in a layer
which is adjacent thereto and is so located with respect to
said timing layer that said processing composition must
first permeate said timing layer before contacting said
adjacent layer, said hydroquinone ester having the following
formula:
<IMG>
wherein R is hydrogen or an acyl group having 1 to about 20
carbon atoms, R' is an acyl group having 1 to about 20 carbon
-31-

atoms, and G is hydrogen, an alkyl group having 1 to about 6
carbon atoms or an aryl group having 6 to about 8 carbon
atoms, and wherein said timing layer has an activation
energy of penetration of the layer by an aqueous alkaline
solution of greater than 18 kcal/mole.
2. The assemblage of Claim 1 wherein:
a) said dye image-receiving layer is located between said
support and said silver halide emulsion layer; and
b) said assemblage also includes a transparent cover
sheet over the layer outermost from said support.
3. The assemblage of Claim 2 wherein said trans-
parent cover sheet is coated with said neutralizing layer
and said timing layer, respectively.
4. The assemblage of Claim 2 wherein said dis-
charging means is a rupturable container containing said
alkaline processing composition and an opacifying agent,
said container being so positioned during processing of said
assemblage that a compressive force applied to said container
will effect a discharge of the container's contents between
said transparent sheet and the layer outermost from said
support.
5. The assemblage of Claim 1 wherein said hydro-
quinone ester is hydroquinone diacetate, hydroquinone mono-
acetate, hydroquinone monohexanoate, 3-t-butyl-4-hydroxy-
phenyl acetate, hydroquinone monobenzoate or 4-hydroxy-3-
tolyl benzoate.
-32-

6. The assemblage of Claim 1 wherein said hydro-
quinone ester is present at a concentration of from about
0.054 g/m2 to about 0.54 g/m2.
7. The assemblage of Claim 1 wherein said timing
layer is a polymeric latex comprising a polymer of from
about 5 to about 35 percent by weight of polymerized ethyl-
enically unsaturated monomer, from about 2 to about 10
percent by weight of polymerized ethylenically unsaturated
carboxylic acid, and from about 55 to about 85 percent by
weight of polymerized vinylidene chloride.
8. The assemblage of Claim 1 wherein said timing
layer is a polymeric latex comprising from about 5 to about
35 percent by weight of acrylonitrile, from about 2 to about
10 percent by weight of a member selected from the group
consisting of acrylic acid and itaconic acid and from about
55 to about 85 percent by weight of vinylidene chloride.
9. The assemblage of Claim 1 wherein said hydro-
quinone ester is in a layer adjacent to said timing layer,
said adjacent layer comprising a polymeric latex having an
activation energy of penetration of the layer by an aqueous
alkaline solution of less than 18 kcal/mole.
10. The assemblage of Claim 9 wherein said adjacent
layer comprises a mixture of cellulose acetate and a maleic
anhydride copolymer, said mixture comprising about 5 to about
50 percent by weight of said copolymer.
- 33 -

11. The assemblage of Claim 1 wherein said dye
image-providing material is a ballasted sulfonamido compound
which is alkali-cleavable upon oxidation to release a diffu-
sible color-providing moiety from a benzene nucleus, said
compound having the formula:
<IMG>
wherein:
a) Col is a dye or dye precursor moiety;
b) Ballast is an organic ballasting radical of such
molecular size and configuration as to render said
compound nondiffusible in said photosensitive element
during development in an alkaline processing composition;
c) G is OR2 or NHR3 wherein R2 is hydrogen or a hydrolyzable
moiety and R3 is hydrogen or an alkyl group of 1 to 22
carbon atoms;
d) Y represents the atoms necessary to complete a benzene
nucleus, a naphthalene nucleus, or a 5- to 7-membered
heterocyclic ring; and
e) n is a positive integer of 1 to 2 and is 2 when G is
OR2 or when R3 is hydrogen or an alkyl group of less
than 8 carbon atoms.
- 34 -

12. An integral photographic assemblage com-
prising:
a) a photosensitive element comprising a transparent
support having thereon the following layers in sequence:
a dye image-receiving layer; an alkaline solution-
permeable, light-reflective layer; an alkaline solution-
permeable, opaque layer; a red-sensitive, direct positive
silver halide emulsion layer having a ballasted redox
cyan dye releaser associated therewith; a green-sensitive,
direct positive silver halide emulsion layer having a
ballasted redox magenta dye releaser associated therewith;
and a blue-sensitive, direct positive silver halide
emulsion layer having a ballasted redox yellow dye
releaser associated therewith;
b) a transparent sheet superposed over said blue-sensitive
silver halide emulsion layer and comprising a transparent
support coated with, in sequence, a neutralizing layer
and a timing layer; and
c) a rupturable container containing an alkaline processing
composition and an opacifying agent, said container being
so positioned during processing of said assemblage that a
compressive force applied to said container will effect a
discharge of the container's contents between said trans-
parent sheet and said blue-sensitive silver halide
emulsion layer;
said assemblage containing a silver halide developing agent,
the improvement wherein said assemblage contains a hydro-
quinone ester either in said timing layer or in a layer
which is adjacent thereto and is so located with respect to
said timing layer that said processing composition must
- 35 -

first permeate said timing layer before contacting said
adjacent layer, said hydroquinone ester having the following
formula:
<IMG>
wherein R is hydrogen or an acyl group having 1 to about 20
carbon atoms, R' is an acyl group having 1 to about 20 carbon
atoms, and G is hydrogen, an alkyl group having 1 to about 6
carbon atoms or an aryl group having 6 to about 8 carbon
atoms, and wherein said timing layer has an activation
energy of penetration of the layer by an aqueous alkaline
solution of greater than 18 kcal/mole.
13. The assemblage of Claim 12 wherein each said
redox dye releaser is a ballasted sulfonamido compound which
is alkali-cleavable upon oxidation to release a diffusible
color-providing moiety from a benzene nucleus, said compound
having the formula:
<IMG>
wherein:
a) Col is a dye or dye precursor moiety;
b) Ballast is an organic ballasting radical of such
molecular size and configuration as to render said
- 36 -

compound nondiffusible in said photosensitive element
during development in an alkaline processing composition;
c) G is OR2 or NHR3 wherein R2 is hydrogen or a hydrolyzable
moiety and R3 is hydrogen or an alkyl group of 1 to 22
carbon atoms;
d) Y represents the atoms necessary to complete a benzene
nucleus, a naphthalene nucleus, or a 5- to 7-membered
heterocyclic ring; and
e) n is a positive integer of 1 to 2 and is 2 when G is OR2
or when R3 is hydrogen or an alkyl group of less than 8
carbon atoms;
and wherein said hydroquinone ester is in a layer adjacent to
said timing layer, said adjacent layer comprising a polymeric
latex having an activation energy of penetration of the
layer by an aqueous alkaline solution of less than 18 kcal/mole.
14. The assemblage of Claim 13 wherein each said
silver halide emulsion is an internal-image silver halide
emulsion, said timing layer comprises a polymeric latex
comprising a polymer of from about 5 to about 35 percent by
weight of polymerized ethylenically unsaturated monomer,
from about 2 to about 10 percent by weight of polymerized
ethylenically unsaturated carboxylic acid, and from about 55
to about 85 percent by weight of polymerized vinylidene
chloride, and said adjacent layer comprises a mixture of
cellulose acetate and a maleic anhydride copolymer, said
mixture comprising about 5 to about 50 percent by weight of
said copolymer.
- 37 -

15. In a process for producing a photographic
transfer image in color from an imagewise-exposed photosensi-
tive element comprising a support having thereon at least
one photosensitive silver halide emulsion layer having
associated therewith a dye image-providing material, said
process comprising treating said element with an alkaline
processing composition in the presence of a silver halide
developing agent to effect development of each of said
exposed silver halide emulsion layers, said processing
composition contacting said emulsion layer prior to contacting
a neutralizing layer; whereby an imagewise distribution of
dye image-providing material is formed as a function of
development and at least a portion of it diffuses to a dye
image-receiving layer to provide said transfer image, whereby
a timing layer associated with said neutralizing layer is
permeated by said alkaline processing composition after a
predetermined time, said timing layer being disposed between
said neutralizing layer and said photosensitive silver
halide emulsion layer so that said processing composition
must first permeate said timing layer before contacting said
neutralizing layer; whereby said alkaline processing composi-
tion is neutralized by means of said neutralizing layer
associated with said photographic element after said predeter-
mined time; the improvement wherein a hydroquinone ester is
employed either in said timing layer or in a layer adjacent
thereto and is so located with respect to said timing layer
that said processing composition must first permeate said
timing layer before contacting said adjacent layer, said hydro-
quinone ester having the following formula:
- 38 -

<IMG>
wherein R is hydrogen or an acyl group having 1 to about 20
carbon atoms, R' is an acyl group having 1 to about 20 carbon
atoms, and G is hydrogen, an alkyl group having 1 to about 6
carbon atoms or an aryl group having 6 to about 8 carbon
atoms, and wherein said timing layer has an activation
energy of penetration of the layer by an aqueous alkaline
solution of greater than 18 kcal/mole.
16. The process of Claim 15 wherein said hydro-
quinone ester is hydroquinone diacetate, hydroquinone mono-
acetate, hydroquinone monohexanoate, 3-t-butyl-4-hydroxyphenyl
acetate, hydroquinone monobenzoate or 4-hydroxy-3-tolyl
benzoate.
17. The process of Claim 15 wherein said hydro-
quinone ester is present at a concentration of from about
0.054 g/m2 to about 0.54 g/m2.
18. The process of Claim 15 wherein said timing
layer is a polymeric latex comprising a polymer of from
about 5 to about 35 percent by weight of polymerized ethyl-
enically unsaturated monomer, from about 2 to about 10
percent by weight of polymerized ethylenically unsaturated
carboxylic acid, and from about 55 to about 85 percent by
weight of polymerized vinylidene chloride.
- 39 -

19. The process of Claim 15 wherein said hydro-
quinone ester is in a layer adjacent to said timing layer,
said adjacent layer comprising a polymeric latex having an
activation energy of penetration of the layer by an aqueous
alkaline solution of less than 18 kcal/mole.
20. The process of Claim 19 wherein said adjacent
layer comprises a mixture of cellulose acetate and a maleic
anhydride copolymer, said mixture comprising about 5 to about
50 percent by weight of said copolymer.
21. In a dye image-receiving element comprising a
support having thereon, in sequence, a neutralizing layer, a
timing layer and a dye image-receiving layer, the improve-
ment wherein a hydroquinone ester is employed in a layer
between said dye image-receiving layer and said support,
said hydroquinone ester having the following formula:
<IMG>
wherein R is hydrogen or an acyl group having 1 to about 20
carbon atoms, R' is an acyl group having 1 to about 20 carbon
atoms, and G is hydrogen, an alkyl group having 1 to about 6
carbon atoms or an aryl group having 6 to about 8 carbon
atoms, and wherein said timing layer has an activation
energy of penetration of the layer by an aqueous alkaline
solution of greater than 18 kcal/mole.
- 40 -

22. In a cover sheet comprising a transparent
support having thereon, in sequence, a neutralizing layer
and a timing layer, the improvement wherein said cover sheet
contains a hydroquinone ester having the following formula:
<IMG>
wherein R is hydrogen or an acyl group having 1 to about 20
carbon atoms, R' is an acyl group having 1 to about 20 carbon
atoms, and G is hydrogen, an alkyl group having 1 to about 6
carbon atoms or an aryl group having 6 to about 8 carbon
atoms, and wherein said timing layer has an activation
energy of penetration of the layer by an aqueous alkaline
solution of greater than 18 kcal/mole.
23. The cover sheet of Claim 22 wherein said hydro-
quinone ester is in a separate layer between said neutralizing
layer and said timing layer, said separate layer comprising
a polymeric latex having an activation energy of penetration
of the layer by an aqueous alkaline solution of less than 18
kcal/mole.
- 41 -

Description

~1 29Z9
This invention relates to photography, and more
particularly to photographic assemblages for color diffu-
sion transfer photography wherein a hydroquinone ester is
employed in or behind a timing layer having a high activa-
tion energy to release a competing developer upon contact
with a processing composition.
Various formats for color integral transfer ele-
ments are described in the prior art, such as U.S. Patents
3,415,6~4; 3,415,645; 3,415,646; 3,647,437; 3,635,707;
: lo 3,756,815 and Canadian Patents 928,559 and 674,082. In
these formats, the image-receiving layer containing the
photographic image for viewing can remain permanently attached
and integral with the image generating and ancillary layers
present in the structure when a transparent support is
employed on the viewing side of the assemblage. The image
is formed by dyes, produced in the image generating units,
diffusing through the layers of the structure to the dye
image-receiving layer. After exposure of the assemblage, an
alkaline processing composition permeates the various layers
20 to initiate development of the exposed photosensitive silver
halide emulsion layers. The emulsion layers are developed
in proportion to the extent of the respective exposures, and
the image dyes which are formed or released in the respective
image generating layers begin to diffuse throughout the ~-
structure. At least a portion of the imagewise distribution
of diffusible dyes diffuse to the dye image-receiving layer
to form an image of the original sub~ect.
Other so-called "peel-apart" formats for color
d~ffusion transfer assemblages are described, for example,
in U,S. Patents 2,983,606; 3,362,8Ig; and 3,362,821, ~n

~L~12~
these formats, the lmage-receiving element is separated from
the photosensitive element after development and transfer of
the dyes to the image-receiving layer.
U.S. Patent 3,462,266 relates to oxazines and
benzoxazines which are cleaved to hydroquinones under alka-
line conditions. The compounds are described as being
auxiliary developer precursors in dye developer image transfer
systems and may be present in various locations such as an
overcoat layer, a spacer layer, a mordant layer or an acidic
layer.
Competing developing agents have been used in
various photographic assemblages heretofore. For example, ~ ~ -
Research Disclosure 15162, November 1976, on page 79, dis-
closes that combinations of certain developing agents with
alkali-soluble competing developers such as hydroquinone,
methylhydroquinone and t-butylhydroquinone are especially
useful in achieving the desired sensitometric curve shape of
the dye image in diffusion transfer assemblages, such as
those employing dye releasers described therein. For example, -
in diffusion transfer systems, optimum development tempera-
tures are not always obtainable. At high temperatures, such
as 32 to 35C, there is faster development with more dye being
released, causing a significant loss in speed, an increase in
DmaX and an increase in Dmin. The presence of a competing
developing agent in the processing composition in the right
concentration will help to alleviate the problem somewhat,
since it will develop silver but will not cause any dye to
be released. The Dmin can be lowered in this manner, but
the speed loss is still there. The increase in DmaX is also
still there, but is not as noticeable to the eye.

lZ9~9
Another problem wlth employing a competing devel-
oper in the processing composition concerns the variability
of the developer layer thickness, or DLT, in a given film
unit. In cameras where the operator hand cranks the film
units out of the camera, the speed at which he operates the
crank will affect the DLT -- e.g., a fast cranking motion
will provide a relatively low DLT. In cameras having a
motor drive, the DLT varies with the viscosity of the proces-
sing composition, the temperature of processing, etc. This
variable DLT, in turn, magnifies the variability of a
competing developer employed in the processing composition,
since it is employed at a relatively low concentration.
In accordance with my invention, I have found that
competing developing agents may be utilized in such a way as
to significantly reduce the speed loss attendant with high
temperature development described above, as well as elimina-
ting the variability of their concentration with variability
in DLT. I have found that employing certain hydroquinone esters
in or behind a timing layer with a high activation energy
20 will provide these advantages. Employing such compounds in -
or behind a timing layer provides a time delay before the
material becomes operative. During processing, the processing
composition penetrates through all or a part of the timing
layer until it contacts the hydroquinone ester. The ester
groups then hydrolyze and the resulting hydroquinone is free
to diffuse to the photosensitive layers to take part in
development. By employing the hydroquinone in its "blocked"
or water-insoluble ester form, it can be easily and advan-
tageously incorporated into an organic solvent-coated poly-
3 meric layer underlying the timing layer, in a preferred

~LlZ~9
embodiment, and it remalns stable upon incubatlon.
The timing layer employed in this invention has a
high activation energy of penetration by aqueous alkali.
It rapidly "breaks down" or "opens up" at a temperature
above about 30C. Below that temperature, its penetration
by the processing composition is relatively slow. However,
this enables the hydroquinone esters to be incorporated in
relatively large amounts. During processing at 32C when
dye release would ordinarily be excessive, this timing layer
breaks down rapidly and allows a large amount of competing
developer to diffuse to the developing silver. The result
is a large amount of silver development, but the dye release
is approximately the same as it would be at lower temperatures.
The speed loss which would otherwise be obtained is, therefore,
significantly reduced. Incorporation of larger amounts of
competing developer in the processing composition would not
provide the same effect, since it would significantly lower
dye release at all temperatures, My invention thus provides
a means for significantly controlling the effects of high
temperature overdevelopment which would ordinarily result in
dark images of high dye density.
A photographic assemblage according to my invention
comprises:
a) a support having thereon at least one photosensitive
silver halide emulsion layer having associated therewith
a dye image-providing material;
b) a dye image-receiving layer;
c~ an alkaline processing composition and means for dis-
charging same within the assemblage;
-- 5 --
.' ' I ~ . .- .

~z~z9
d) a neutralizing layer for neutrallzlng the alkaline
processing composition; and
e) a timing layer disposed between the neutrallzing layer
and the photosensitive silver halide emulsion layer so
that the processing composition must first permeate
the timing layer before contacting the neutrallzing
layer;
the assemblage containing a silver halide developing agent,
and wherein the assemblage contains a hydroqulnone ester
either (1) in the timing layer, or (2) in a layer which is
ad~acent thereto and is so located with respect to the timing
layer that the processing composition must first permeate
the timing layer before contacting the ad~acent layer, the
hydroquinone ester having the following formula:
OR
I * G
t
OR'
wherein R is hydrogen or an acyl (including substituted acyl)
group having 1 to about 20 carbon atoms, R is an acyl (includ-
ing substituted acyl~ group having 1 to about 20 carbon atoms,
and G is hydrogen, an alkyl (including substituted alkyl) group
having 1 to about 6 carbon atoms or an aryl group having 6 to
about 8 carbon atoms, and wherein the timing layer has an
activation energy of penetration of the layer by an aqueous
alkaline solution of greater than 18 kcal/mole.
In the above formula, G can be hydrogen, an alkyl
group of 1 to about 6 carbon atoms, such as methyl, ethyl,
isopropyl, t-butyl, etc, or an aryl group having 6 to about 8
.'
-- 6 --

~ L2~29
carbon atoms, such as phenyl, _-tolyl, _-methoxyphenyl,
etc, as long as the compound will diffuse at a sufficient
rate when the acyl group or groups are hydrolyzed. In a
similar manner, when each of R and R in the formula is an
acyl group, any such group such as acetyl, propionyl, benzoyl,
ethoxycarbonyl, ethoxalyl, etc, can be employed, so long as
it can be hydrolyzed to the corresponding hydroquinone.
The hydroquinone esters can be employed according to
my invention at any concentration effective for the intended
purpose. Good results have been obtained at a concentration
of from about 0.054 g/m2 to about 0.54 g/m2, and especially
good results have been obtained at a concentration of from
about 0.10 g/m2 to about 0.45 g/m2.
Examples of hydroquinone esters useful in my inven-
tion include the following:
(1) Hydroquinone diacetate
O
O-C-CH3
I ~
t
O-C--CH
o
(2) Hydroquinone monohexanoate
o
C CsH~ ~ n
I~ ~
OH

~z~29
(3) 3-t-butyl-4-hydroxyphenyl acetate
O
O--C-CH
1 3
t C--CH3
CH3
(4) Hydroquinone monoacetate
O
O--C-C H3
OH
(5) Hydroquinone monobenzoate
O
O- C--C H
OH
(6) 4-Hydroxy-3-tolyl benzoate
O
O--C--C H
6 5
OH

292~
As noted above, the hydroqulnone esters employed
ln this lnvention can be employed elther ln or behlnd the
timing layer with respect to the side of appllcatlon of the
processing composltion. Preferably, lt ls lncorporated ln the
timing layer so that the release of the competing developer
occurs after a finite time. When a longer delay is deslred,
the compound ls merely incorporated ln an ad~acent layer,
behind the timing layer and farther away from the developing
silver halide layers. This layer can be contiguous to the
timing layer or can be located in an ad~acent layer several
layers away from the timing layer, depending upon the results
desired.
Particularly preferred timing layers useful in thls
invention comprise a polymeric latex having an activation
energy of penetration of the layer by an aqueous alkallne
solution of greater than 18 kcal/mole. Such latex tlming
layers result from a coalescence or partial coalesence of
polymeric particles from an aqueous latex. Preferred latex
timlng layers are described, along with their method of
20 synthesis, inCdn. Application Serial No.275~94l of Hannie,
filed Apri~ 12, 1977.
These timing layers delay the
neutralization of the alkaline processlng compositlon by the
acid layer so that production of a hlgh quallty dye lmage ls
more reproducible over a large temperature range.
The activation energy of penetration of polymeric
layers by aqueous alkaline solutions can be determined by
the following simple test.
A thymolphthalein dye or cresol red dye indicator
3~ is coated on a polyethylene terephthalate film support at
210 mg/m2 with 6.6 g/m2 gelatin in the case of thymolphthalein
or 2.2 g/m2 ln the case of cresol red.
_ g _
'B
. , 1

z9
A processing composition comprising a pod which
contains about o.84 N potassium hydroxide and about 5 percent
carboxymethyl cellulose in water, along with other conven-
tional developer ingredients, is spread between the element
containing the indicator dye and a sample of a cover sheet by
passing the "sandwich" between a pair of ~uxtaposed pressure
rollers so that the developer layer thickness is 0.1 mm.
The cover sheet comprises a polyethylene terephthalate
support containing a first layer of a 30/70 (by weight) copolymer
of poly(butyl acrylate-co-acrylic acid), a second layer of 50/50
(mole ratio) polymer of poly(styrene-co-maleic anhydride) at
2.2 g/m2 and the outer layer being the polymer for which the
activation energy is to be determined.
The time required to reduce the pH of a unit to pH
10 as measured by the color change of the thymolphthalein dye
from blue to colorless or to pH 8 as measured by the change of
the cresol red dye from red to yellow is measured at various
temperatures within the range of 13 to 54C. The time in
seconds is plotted on a logarithmic scale against the recip-
rocal of the temperature expressed in K. The activationenergy in kcal/mole is determined from the slope of the
straight line portion of the curve according to the formula:
~Ea (activation energy) = 0.00458 X log Y2/Y
l/T2 l/Tl
where T2 is the higher temperature and Tl is the lower
temperature and Y2 is the time at T2 and Yl is the time at
Tl. The thickness of the acid layer and the polymer layer
is not critical to the proper determination of activation
energy.
-- 10 --

A discussion of activation energy calculations
can be found in Kinetics and Mechanism, second edition,
New York, John Wiley and Sons, 1961, pages 22 through 25.
Latex polymers having an activation energy to
penetration by aqueous alkaline solution of greater than
18 kcal/mole include poly(methyl acrylate-co-ltaconic acid-
co-vinylidene chloride) and the like.
Preferred polymeric latexes having an activation
energy of penetration to aqueous alkaline solution of greater
than 18 kcal/mole are terpolymers of from about 5 to about 35
percent by weight of polymerized ethylenically unsaturated
monomer, from about 2 to about 10 percent by weight of poly-
merized ethylenically unsaturated carboxylic acid and from
about 55 to about 85 percent by weight of polymerized
vinylidene chloride.
Any ethylenically unsaturated monomer which is
different from the other monomers in the polymeric latex can
be used to prepare the terpolymer including alkyl acrylates
and methacrylates such as methyl acrylate, ethyl acrylate,
propyl acrylate, butyl acrylate, butyl methacrylate and the
like; vinyl esters, amides, nitriles, ketones, halides, ethers,
olefins, diolefins and the like as exemplified by acrylonitrile,
methacrylonitrile, styrene, alpha-methyl styrene, acrylamide,
methacrylamide, vinyl chloride, methyl vinyl ketone, fumaric,
maleic and itaconic esters, 2-chloroethylvinyl ether, dimethyl-
aminoethyl methacrylate, 2-hydroxyethyl methacrylate, N-vinyl-
succinamide, N-vinylphthalimide, N-vinylpyrrolidone, butadiene,
ethylene and the like. Preferred monomers are methyl acrylate
and acrylonitrile.
-- 11 --

~29~29
Examples of ethylenlcally unsaturated carboxylic
acids which can be lncluded in the polymer lnclude acryllc
acid, methacrylic acid, itaconlc acid, fumarlc acid, maleic
acid, their anhydrides, and the like. The preferred carboxylic
acids are acrylic acid and itaconic acid.
A preferred terpolymer useful in the invention
comprises 15 weight percent methyl acrylate, 83 weight percent
vinylidene chloride and 2 weight percent ltaconic acid. Further
examples of latex polymers useful herein can be ~ound ln U.S.
Patents 3,271,345; 2,627,088; 2,491,023; 2,779,684; 3,437,484;
2,943,937 and 3,143,421.
The latex timing layer can generally be employed over
a broad range of coverages. Preferred coverage for the layer
ranges from about 1.0 g/m2 to 6.0 g/m2 and more pre~erably
from about 1 to 3 g/m2.
In a preferred embodlment of my lnventlon, the hydro-
quinone esters are incorporated in an ad~acent layer comprlsing
a timing layer, which layer, in turn is coated with the
latex timing layer having a high activation energy described
above. In this "doublet' timing layer embodiment, the first
timing layer in which the hydroquinone esters are employed
comprising a polymeric latex having an activation energy of
penetratlon to aqueous alkaline solution of less than 18
kcal/mole. The second timing layer ls as described above
and comprises a polymeric latex havlng an actlvatlon energy
of penetration to aqueous alkallne solutlon of greater than
18 kcal/mole. This "double" timing layer system ls described
more fully in Cdn. Applicatlon Serial No.275,941 of ~annie
and Ducharme, filed April 12, 1977.
~ - 12 -

2~
Examples of polymers for the flrst timlng layer
described above having an activatlon energy of penetratlon
of aqueous alkaline composltion of less than 18 kcal/mole are
mixtures of cellulose acetate and a maleic anhydrlde copolymer
with 5 to 50 percent by weight of the mixture belng sald
copolymer such as described in Cdn. Patent 1,072,800 issued
March 4, 1980.
The maleic anhydride copolymer in thls timing layer
should be employed in a concentration of about 2 to about 20
percent by weight, depending somewhat on the other comonomer.
A 5 to 20 percent concentration has been found to be particu-
larly effective. The thickness of this tlming layer should be
such as to provide a coverage of about 1 to about 5 g/m2.
The cellulose acetate employed in that layer will
usually have acetyl contents of about 37 to 40 percent by
weight, the 37 percent being substantially more permeable than
the 40 percent acetyl. Mixed esters can also be employed,
such as cellulose acetate propionate, cellulose acetate
butyrate, etc.
The maleic anhydride copolymer can be selected from a
wide variety of materials, so long as it ls compatible with the
cellulose acetate employed to provide a clear film. Particu-
larly good results are obtained with poly(styrene-co-maleic
anhydride), poly(ethylene-co-maleic anhydrlde) and poly(methyl
vinyl ether-co-maleic anhydride).
Examples of other layers containlng polymers havlng
an activatlon energy of less than 18 kcal/mole are polyvinyl
acetate, cellulose acetate phthalate, partial acetals of
polyvinyl alcohol, a polymer latex of butyl acrylate-diacetone
- 13 -

Z~
acrylamide-styrene-methacryllc acid (60/30/4/6) as described
in ~.S. Patent 3,785,815, mixtures of polyvinyl acetate and
polyvinyl alcohol such as polyvinyl acetate latex in 78/22
ratio with polyvinyl alcohol, cellulose acetate (40 percent
acetate in 95/5 ratio with poly[styrene-co-maleic anhydride]
[50/50 mole ratio]) as described in Canadian Patent
1,072,800 and the like.
One embodiment of an assemblage Or an integral
transfer color element and a process for producing a photo-
graphic transfer image in color in which my invention can beemployed is disclosed in Canadian Patent 928,559. In this
embodiment, the support for the photosensitive element is
transparent and is coated with an image-receiving layer, a
light-reflective layer, an opaque layer and photosensitive
layers, having associated therewith dye image-providing
material layers. A rupturable container containing the
alkaline processing composition described above and an
opacifier such as carbon black is positioned ad~acent the
top layer and a transparent cover sheet. The cover sheet
comprises a transparent support which is coated with a
neutralizing layer and a timlng layer containing the hydro-
quinone esters according to the invention. The film unit is
placed in a camera, exposed through the transparent cover
sheet and then passed through a pair of pressure-applying
members in the camera as it is being removed therefrom. The
pressure-applying members rupture the container and spread
processlng composition and opacifier over the image-forming
portion of the assemblage to protect it from -exposure. The
processing compositlon develops each silver hallde layer and
dye images are formed as a result of development which
~ - 14 -

'~lZ~Z9
diffuse to the image-receivlng layer to provide a right-
reading image which is viewed through the transparent support
on the opaque reflecting layer background. The neutralizlng
layer then neutrallzes the alkallne processing compositlon
after the tlmlng layer has been permeated, thus "shutting
down" the system. For further details concerning the format
of this particular lntegral assemblage, reference is made to
the above-mentioned Canadian Patent 928,559.
10Another embodiment of an assemblage of an integral
transfer color element and a process for produclng a photo-
graphic transfer image in color ln which my invention can be
employed is described in U.S. Patent 3,415,644. In this
embodiment, the negative comprises an opaque support which
is coated with photosensitive layers having associated
therewith dye image-providing material layers. A rupturable
container containing the alkaline processing composition
described above, TiO2 and an indicator dye (see U.S. Patent
3,647,437) is positioned ad~acent the top layer and a trans- ;~
parent receiver. The receiver comprises a transparent
support which is coated with a neutralizing layer, a timing
layer containing the hydroquinone esters according to the
invention and an image-receiving layer. The film unit is
placed in a camera, exposed through the transparent receiver
and then passed through a pair of pressure-applying members
in the camera as it is belng removed therefrom. The pressure-
applylng members rupture the contalner and spread processing
composltlon, TiO2 and indicator dye over the image-forming
portion of the assemblage to protect it from exposure. The
processing ccmposltion develops each sllver hallde layer and
dye images are formed as a result of development whlch
15 -

Z9
diffuse to the ~mage-receiving layer which ls viewed through
the transparent support on a white background -- the lndicator
dye having "shifted" to a colorless form as the alkali ls
consumed by the neutralizing layer. As before, the neutral-
izing layer then neutralizes the alkaline processing composi-
tion after the timing layer has been permeated, thus "shutting
down" the syste~. For further details concerning the format
of this particular assemblage, reference is made to the
above-mentioned U.S. Patent 3~415~644~
Since the image ln this embodiment is
geometrically reversed, an image-reversing optlcal system
such as a mirror in the camera is needed to reverse the
image so that a right-reading image is vlewable in the dye
image-receiving layer.
Another embodiment of an assemblage of a color
diffusion transfer film unit in which this invention can be
employed in a dye image-receiving element is described in
U.S. Patent 3~362~819~ The image-receiving element comprises
a support, which is usually opaque, having thereon a neutral-
izing layer, a timing layer containing the hydroquinoneesters of the invention and a dye image-receivlng layer.
For further details concernlng the use of such an element ln
color transfer assemblages, reference is made to the above-
mentloned U.S. Patent 3~362~819~
Stlll other useful lntegral formats in whlch my
lnventlon can be employed are descrlbed ln U.S. Patents
3~415~645; 3~415~646; 3~647~437; ~635~707~ and British
Patent 1, 330~ 524 ~ \
The photosensltlve element useful in my invention
can be treated with an alkaline processlng composltlon to
r \ ~ 16

~ ~ 12~29
effect or initiate development in any manner. A preferredmethod for applying processing composition is by use of a
rupturable container or pod which contains the composition.
In general, the processing composition employed in my lnvention
contains the developing agent for development. Where the
developer is incorporated in the photosensitive element, the
alkaline processing composition serves to activate the
incorporated developer.
The dye image-providing materials which may be
employed in my invention generally may be characterized as
either (1) initially soluble or diffusible in the processing
composition but are selectively rendered nondiffusible in an
imagewise pattern as a function of development, such as
those disclosed, for example, in U.S. Patents 2,647,049;
2,661,293; 2,698,244; 2,698,798; 2,802,735; 2,774,668; and
2,983,606; or (2) initially insoluble or nondiffusible in
the processing composition but which are selectively rendered
diffusible in an imagewise pattern as a function of develop-
ment, such as those disclosed, for example, in U.S. Patents
3,227,550; 3,227,551; 3,227,552; 3,227,554; 3,243,294; and
3,445,228. These materials may be preformed dyes or dye
precursors, e.g., color couplers, oxichromic compounds and
the like.
In a preferred embodiment of my invention the dye
image-providing material is a nondiffusible or ballasted
redox dye releaser. Such compounds are, generally speaking,
compounds which can be oxidized by oxidized developing
agent, i.e., cross-oxidized, to provide a species which as a
function of oxidation will release a diffusible dye, such as
30 by alkaline hydrolysis. Such dye releasers are described in
U.S. Patents 3,725,062 of Anderson and Lum issued April 3,
- 17 -

l~lZ~ 9
1973; 3,698,897 of Gompf and Lum lssued October 17, 1972;
3,443,939 and 3,443,940 Or Bloom et al lssued May 13, 1969;
3,928,312 of ~leckensteln lssued December 23, 1975; 3,929,760
of Landholm et al lssued December 20, 1975; 3,942,987 of
Landholm et al issued March 9, 1976~l 3,932,380 of Krutak et
al issued January 13, 1976; 3,980,479 of Fields et al issued
September 14, 1976; and U.S. Publlshed Patent Appllcatlon
B-351,673 of Fleckenstein et al published January 28, 1975;
German OLS 2,406,664; Canadian Patent 1,047,821Of Kxutak et al
issued February 6, 1979; Canadian Patent 1,047,030 of Haase et
al issued ~anuary 23, 1979; Canadian Patent 1,073,451 of
~inshaw et al issued March 11, 1980; and Canadian Application
283,408 of Chasman et al filed July 25, 1977.
In an especlally preferred embodiment of my inven-
tion, the dye releasers such as those in the Fleckenstein
et al patents and appllcatlons referred to above are employed.
Such compounds are ballasted sulfonamldo compounds which are
alkali-cleavable upon oxldation to release a diffusible dye
from the nucleus and have the formula:
Y -~-- (Ba l l ast)
n- 1
2 C I
wherein:
a) Col is a dye or dye precursor moiety;
b) Ballast is an organic ballasting radical of such
molecular size and configuration (e.g., simple organic
- 18 -
'~"3

~12~29
groups or polymeric groups) as to render the compound
nondiffusible ln the photosensitlve element durlng
development ln an alkaline processing compositlon;
c) G is OR2 or NHR3 wherein R2 is hydrogen or a hydrolyzable
molety and R3 ls hydrogen or a substituted or unsubsti-
tuted alkyl group of 1 to 22 carbon atoms, such as
methyl, ethyl, hydroxyethyl, propyl, butyl, secondary
butyl, tert-butyl, cyclopropyl, 4-chlorobutyl, cyclo-
butyl, 4-nltroamyl, hexyl, cyclohexyl, octyl, decyl,
octadecyl, docosyl, benzyl, phenethyl, etc., (when R3
is an alkyl group of greater than 6 carbon atoms, it
can serve as a partlal or sole Ballast group);
d) Y represents the atoms necessary to complete a benzene
: nucleus, a naphthalene nucleus, or a 5- to 7-membered
heterocyclic ring such as pyrazolone, pyrimidine, etc; and
e) n is a positive integer of 1 to 2 and is 2 when G ls OR2
or when R3 is a hydrogen or an alkyl group of less than
8 carbon atoms.
In another preferred embodlment of my lnventlon,
initially diffusible dye image-providing materials are
employed such as dye developers, including metal complexed
dye developers such as those described in U.S. Patents
3,453,107; 3,544,545; 3,551,406; 3,563,739; 3,597,200;
- 3,705,184; and oxichromic developers as described and claimed
in my coworkers' Lestina and Bush Applicztion Canadian Patent
995,948 issued August 3, 1976.
- 19 _

~12~29
When oxichromic developers are employed, the lmage is formed
by the diffusion of the oxichromic developer to the dye
image-receiving layer where it undergoes chromogenic oxida-
tion to form an image dye.
The assemblage of the present invention may be
used to produce positive images in single- or multicolors.
In a three-color system, each silver halide emulsion layer
of the film assembly will have associated therewith a dye
image-providing material possessing a predominant spectral
absorption within the region of the visible spectrum to
which said silver halide emulsion is sensitive, i.e., the
blue-sensitive silver halide emulsion layer will have a
yellow dye image-providing material associated therewith,
the green-sensitive silver halide emulsion layer will have a
magenta dye image-providing material associated therewith,
and the red-sensitive silver halide emulsion layer will have
a cyan dye image-providing material associated therewith.
The dye image-providing material associated with each silver
halide emulsion layer may be contained either in the silver
halide emulsion layer itself or in a layer contiguous to the
silver halide emulsion layer.
The concentration of the dye image-providing
materials that are employed in the present invention may be
varied over a wide range depending upon the particular com-
pound employed and the results which are desired. For
example, the dye image-providing compounds may be coated as
dispersions in layers by using coating solutions containing
a ratio between about 0.25 and about 4 of the dye image-
providing compound to the hydrophilic film-forming natural
material or synthetic polymer binder, such as gelatin,
-20 -
.

Z9
polyvinyl alcohol, etc., which ls adapted to be permeated by
aqueous alkaline processing composltion.
Any silver halide developing agent can be employed
in my invention depending upon the particular chemistry
system involved. The developer may be employed in the
photosensitive element to be activated by the alkaline
processing composition. Specific examples of developers
which can be emplsyed in my invention include:
hydroquinone
N-methylaminophenol
Phenidone (l-phenyl-3-pyrazolidinone)
Dimezone (l-phenyl-4,4-dimethyl-3-pyrazolidinone)
aminophenols
N-N-diethyl ~-phenylenediamine
3-methyl-N,N-diethyl-_-phenylenediamine
N,N,N',N'-tetramethyl-~-phenylenediamine
4-hydroxymethyl-4-methyl-1-phenyl-3-pyrazolidinone
4,4-bis(hydroxymethyl)-1-phenyl-3-pyrazolidinone, etc.
The black and white developing agents are preferred, however,
since the color developers are generally slower, can cause
stain, and can cause dermatitis if not handled properly.
In using dye releaser compounds in my invention
which produce diffusible dye lmages as a function of develop-
ment, either conventional negative-working or direct-positlve
sllver halide emulslons may be employed. If the sllver
halide emulsion employed is a direct-positive silver halide
emulsion, such as an internal-image emulsion deslgned for use
ln the internal lmage reversal process or a fogged, dlrect-
positive emulsion such as a solarizing emulsion, which is
3 developable in unexposed areas, a positive image can be
obtained in certain embodiments on the dye image-receiving
layer. After exposure of the film unit, the alkaline proces-
sing composition permeates the various layers to initiate
development of the exposed photosensitive silver halide
emulsion layers. The developing agent present in the film
- 21 -

2~9
unit develops each of the silver hallde emulsion layers ln
the unexposed areas (since the silver hallde emulslons are
d~rect-positive ones), thus causing the developing agent to
become oxidized imagewise corresponding to the unexposed areas
Or the direct-positive silver halide emulslon layers. The
oxidized developlng agent then cross-oxidizes the dye-
releasing compounds, and the oxidized form of the compounds
then undergoes a base-catalyzed reaction to release the
dyes imagewise as a function of the imagewise exposure of
each of the silver halide emulsion layers. At least a
portion of the lmagewlse dlstrlbutlons of diffusible dyes
diffuse to the image-receiving layer to form a positive
image of the original sub~ect.
Internal-image sllver halide emulsions useful in
this invention are described more fully in the November 1976
edition of Research Disclosure, pages 76 through 79.
The varlous sllver halide emulsion layers of a
color film assembly of the invention can be disposed in the
usual order, i.e., the blue-sensitive silver hallde emulsion
layer first with respect to the exposure side, followed by
the green-sensitive and red-sensitive silver halide emulsion
layers. If desired, a yellow dye layer or a yellow colloidal
silver layer can be present between the blue-sensitive and
green-sensitive silver halide emulsion layer for absorbing
or filtering blue radiation that may be transmitted through
the blue-sensitive layer. If desired, the selectively
sensitized silver halide emulsion layers can be disposed in
a different order, e.g., the blue-sensitive layer flrst with
3 respect to the exposure slde, followed by the red-sensitive
`~ - 22 -

Z9
and green-sensitive layers.
While the alkaline processing composition used ln
this invention can be applied to the assemblage by the use
of rupturable contalners as described previously, other
means ~or discharging the composition within the assemblage
could also be used, e.g., inter~ecting the compositlons with
communicating members similar to hypodermic syringes which
are attached either to a camera or camera cartridge.
In a color photographic assemblage according to
this invention, each silver halide emulsion layer containing
a dye image-providing material or having the dye image-
providing material present in a contiguous layer may be
separated from the other silver halide emulsion layers in
the negative portion of the film unit by materials including
gelatin, calcium alginate, or any of those disclosed in U.S.
Patent No. 3,384,483, polymeric materials such as polyvinyl-
amides as disclosed in U.S. Patent 3,421,892, or any of
those disclosed in French Patent 2,028,236 or U.S. Patents
Nos. 2,992,104; 3,043,692; 3,044,873; 3,061,428; 3,069,263,
3,069,264; 3,121,011 and 3,427,158.
Generally speaking, except where noted otherwise,
the silver halide emulsion layers in the invention comprise
photosensitive silver halide dispersed in gelatin and are
about o.6 to 6 microns in thickness; the dye image-providing
materials are dlspersed in an aqueous alkaline solution-
permeable polymeric binder, such as gelatin, as a separate
layer about 0. 2 to 7 microns in thickness; and the alkaline
solution-permeable polymeric interlayers, e.g., gelatin, are
about 0. 2 to 5 microns in thickness. Of course, these
30 ' thicknesses are approximate only and can be modified according
to the product desired.
- 23 -

1~2S~9
Scavengers for oxldized developing agent can be
employed in various lnterlayers of the photographlc elements
of the invention. Suitable materials are disclosed on page
83 of the November 1976 edition Or Research Disclosure.
The alkaline solution-permeable, llght-reflectlve
layer employed ln certaln embodlments of photographic assem-
blages of thls invention are described more fully in the
November 1976 edition of Research Disclosure, page 82,
The neutralizing layer employed in my inventlon
whlch becomes operative after permeation of the processing
composition through the timing layer will effect a reductlon
in the pH of the image layers from about 13 or 14 to at
least 11 and preferably 5 to 8 within a short tlme after
imblbltion. Suitable materlals and their functionlng are
disclosed on pages 22 to 23 of the July 1974 edltion of
Research Disclosure and pages 35 to 37 of the July 1975
edition of Research Disclosure.
The lnert timlng or spacer layer employed in my
invention over the neutralizing layer "tlmes" or controls
the pH reductlon as a functlon of the rate at whlch alkall
dlffuses throughout the lnert spacer layer. Examples
of such timing layers and their functioning are disclosed in
the Research Disclosure articles mentioned in the paragraph
above concerning neutralizing layers.
Any material can be employed as the image-receiving
layer in this invention as long as the desired function of
mordanting Gr otherwise fixing the dye images will be
- 24 -

~12~
obtained. The particular materlal chosen wlll, Or course,
depend upon the dye to be mordanted. Sultable materlals are
disclosed on pages 80 to 82 of the November 1976 editlon of
Research Disclosure.
The alkaline processing composition employed ln
this lnvention is the conventional aqueous solutlon Or an
alkallne material, e.g., alkali metal hydroxldes or carbonates
such as sodium hydroxide, sodium carbonate, or an amine such
as diethylamine, possessing a pH Or at least about 11, and
preferably containing a developlng agent as descrlbed pre-
viously. Suitable materials and addenda frequently added
to such compositions are disclosed on pages 79 to 80 of the
November 1976 edition Or Research Dlsclosure.
The supports rOr the photographlc elements of thls
lnventlon can be any material as long as lt does not deleter-
iously effect the photographic propertles Or the film unit
and is dimensionally stable. Typlcal flexlble sheet materials
are descrlbed on page 85 of the November 1976 edltion of
Research Dlsclosure.
The sllver hallde emulslons useful in this invention,
both negative-worklng and direct-positlve ones, are well known
to those skllled ln the art and are descrlbed ln Product
Llcensing Index, Volume 92, December 1971, publication 9232,
paragraph I, "Emulslon types", they may be chemlcally and
spectrally sensltized as descrlbed on page 107, paragraph III,
"Chemical sensltization", and pages 108 and 109, paragraph XV,
"Spectral sensltization", of the above article; they can be

29
protected against the production of fog and can be stablllzed
against loss of sensitivity durlng keeping by employlng the
materials described on page 107, paragraph V, "Antlfoggants
and stabilizers", of the above article; they can contain
development modifiers, hardeners, and coatlng aids as des-
cribed on pages 107 through 108, paragraph IV, "Development
modifiers"; paragraph VII, "Hardeners"; and paragraph XII,
"Coating aids", of the above article; they and other layers
in the photographic elements used in this inventlon can
contain plasticizers, vehicles and filter dyes descrlbed on
page 108, paragraph XI, "Plasticizers and lubricants", and
paragraph VIII, "Vehicles", and page lO9, paragraph XVI,
"Absorbing and filter dyes", of the above article; they and
other layers in the photographic elements used in this
invention may contain addenda which are incorporated by
using the procedures described on page lO9, paragraph XVII,
"Methods of addition", of the above article; and they can be
coated by using the various techniques described on page
lO9, paragraph XVIII, "Coating procedures", of the above
article.
The term "nondiffusing" used herein has the meaning
commonly applied to the term in photography and denotes mater-
ials that for all practical purposes do not migrate nor wander
through organic colloid layers of the photographic elements of
the invention in an alkaline medium, preferably when processed
in a medium having a pH of ll or greater. The same meaning
ls to be attached to the term "immobile". The term "diffusible"
as applied to the materials of this invention has the converse
- 26 -

~2~9
meaning and denotes materials having the property of diffu-
sing effectively through the collold layers of the photo-
graphic elements in an alkaline medium in the presence of
"nondiffusing" materials. "Mobile" has the same meaning.
The term "associated therewith" as used herein is
intended to mean that the materials can be in either the same
or different layers so long as the materials are accessible
to one another.
The following example further illustrates the
invention.
EXAMPLE
(A) A control cover sheet was prepared by coating the
following layers in the order received on a 0.004-inch poly-
(ethylene terephthalate) film base:
(1) An acid layer comprising 15.5 g/m2 of poly(n-butyl
acrylate-co-acrylic acid (30 percent acrylic acid) and
o.43 g/m2 of Dicalite (trademark), Grade 103 diatomaceous
earth;
(2) A timing layer comprising 1.929 g/m2 of cellulose acetate
(40 percent acetyl) and 0.24 g/m2 of poly(styrene-co-
maleic anhydride); and
(3) A second timing layer of 2.15 g/m2 of poly(acrylonitrile-
co-vinylidene chloride-co-acrylic acid) (15:79:6).
(B) Another cover sheet was prepared sim~ilar to (A),
except that layer 2 contained 0.22 g/m2 of hydroquinone mono-
acetate.
An integral photographic element of the type des-
cribed in E:lement 10 of U.S. Patent 4,030,925 of Leone et al,

issued June 21, 1977, was exposed to a tungsten llght source
through a graduated density multicolor test obJect.
The following processing composition was employed
in a pod and spread between the exposed photosensitive ele-
ment and the transparent cover sheets described above at 16C
and 38C by passing the transfer "sandwich" between a pair of
~uxtaposed rollers so that the liquid layer was about .003
inch.
The pod composition was as follows:
Distilled water 850 ml
Potassium hydroxide 46.8 g
Sodium sulfite (anhydrous) 1.0 g
5-methyl-1,2,3-benzotriazole3.8 g
4-hydroxymethyl-4-methyl-1-
phenyl-3-pyrazolidone12.0 g
t-butylhydroquinone 0.3 g
Carboxymethyl cellulose56.6 g
Tamol SN (Trademark of Rohm
and Haas Company) dispersing
agent 8.8 g
Carbon 171.0 g
Potassium fluoride 10.0 g
Methyl hydroquinone 0.1 g
1,4-cyclohexanedimethanol1.0 g
Sodium hydroxide 3.4 g
4-chloro-3,5-xylenol 0.04 g
The sensitometric changes observed upon processing
these elements at 16C and 38C were as follows:
- 28 -

,9
~al 3 0
Ir I O
I I O
* ~)
~S:~ ~D N
bO ~
OF~ o o
~ ~ I +
C~
~1 -'
~ O O ~
m I + td
~a
N C~
a~ . . o
~; c o h
X ~ NIr~ ~)
t~ a~ o o a
~e h o o
C~
C3 ~
~ ~D ~1
Q) ~ ~
m o o
~a ~ ~
Q~ .
~ O O J~
+ +
S ~~ 3 ,~ ~
e~ O O
~ h c o o
~ ~ + +
~ o o
, 1 o ~
m + ~
h
~d
~1 ~ e
e cC J~ m
a, o
C) *
--29

The above results indicate that the speed loss
has been significantly reduced in Element B, especially ln
the figures given for the red region.
The invention has been described in detail with
particular reference to preferred embodiments thereof, but
it will be apparent that variations and modifications can be
effected within the spirit and scope of the invention.
- 30 -