Note: Descriptions are shown in the official language in which they were submitted.
The present invention relates to a novel light-
sensitive silver halide photographic material and the processing
method therefor. Particularly, it relates to a novel lith type
ligh-t-sensitive silver halide photographic material for obtaining
a photographic image with an especially high contrast, high
sharpness and high resolving power, and to the processlng method
therefor.
More particularly, it relates to a novel light-
sensitive silver halide photographic material which is applicable
advantageously to a light-sensitive silver halide photographic ``
material with a high contrast suitable for forming a dot- or
line-image on a lith (printing) light-sensitive silver halide
material or a copying light-sensitive material, as well as to
the processing method therefor.
It has been known to form a photographic image with
an extremely high contrast by using some kind of a light-sensitive
silver halide photographic material.
It has been known, for example, to obtain a high
contrast image, e.g. a line- or do-t-image by treating, with
an alkaline hydroquinones developing solution containing sulfite
ions in a very low concentration, a light-sensitive-material
which comprises a silver halide emulsion containing silver chlo-
ride in a high content (at least more than 50 mole %) and further
containing silver iodide less than 5 mole ~, the grains of which
emulsion being minute ~average grain size; ca. 0.3 ~), uniform
in size and shape, and the grain size distribution thereof being
narrow. The above-mentioned kind of light-sensitive silver
halide material is known as the lith type light-sensitive material.
In printing, there is usually required such a process
as to convert a con~inuous gradation original to a dot image;
- 2 -
that is a process to convert the densities of the continuous
gradation to a predetermined numbered assembly of dots respec-
tively having areas o~ the same densities but proportional in
size to the densities of the continuous gradation. In order
to carry out this, the lith type light-sensitive material is
subjected to development, after photographing the original image
through a cross- or contact-screen, to form the dot image on the
light-sensitive material.
For this purpose there has been employed a light-
sensitive silver halide photographic material containing a silver
halide emulsion, the grains of which being minute and being uni-
form in size and shape. Even when this kind of a light-sensitive
silver halide photographic material is employed, the intermediate
density region (undesirable continuous gradation parts) is
reproduced, beside the maximum density region and the minimum
one (fog), when the material is processed with a standard black
and white developing solution. The intermediate densit~v reyion
or the so-called flinge, undesirable for producing a printing
plate and makes the dot qualit~ worse.
There has heretofore been employed the lith type light-
sensitive material also for the reproduction of a line image.
For the same reason, however, there have been obtained images
having at best the ~-value of 5 - 6 of the characteristic curve,
which value is lower than 7 - 9 required for forming the desirable
line-image, if the standard black and white developincJ solution is
employed. In order to avoid this, there has been employed, as
mentioned above, a specific developing solution called " infec-
tious developing solution." It is indispensablel however, to
maintain the sulfite concentration in the infectious developing
solution as low as possible to obtain a high con-trast image, but
such the developing solution is very poor in storability because
of the low concentration o~ the sul~ite so that this have caused
a big trouble in printing business. Every effort has been made,
however, to improve the storability. Nevertheless, such efforts
have not been so successful. As a result, an ordinary developing
solution for a continuous gradation, such as Metol/hydroquinone
or phenidone/hydroquinone developing solution which is excellent
in the storability, is recommended for processing the light-
sensitive materials. However there has been known no method
capable of obtaining a dot image with a good dot quality, by
using such the developing solution.
It is, therefore, the primary object of the invention
to provide a novel light-sensitive silver halide photographic
material and the processing method thereof to obtain a high
contrast silver image.
It is another object of the invention to provide a lith
type light-sensitive silver halide material ~eing dye-sensitized
and having a great development stability containing a tetrazolium
compound suitable for obtaining a dot- or line-image.
It is still another object of the invention to provide
a novel processing method of the above-mentioned lith type light-
sensitive silver halide material to obtain a high contrast black
and silver image, especially a dot- or line-image.
The inventors have found, after extensive studies to
attain the above-mentioned objects, that the object can be attained
by processing a lith type light-sensitive silver halide photo-
graphic material containing, in a hydrophilic colloidal layer
silver halide grains having a narrow grain size distribution,
a tetrazolium compound and a sensitizing dye, after exposure,
with a developing solution containing a hydro~uinones developing
agent as a maln developing agent.
In accordance with the invention, there can be formed
a superior line- or dot-image~ without employing the infectious
development, by processing a light-sensitive silver halide
photographic material having (coated on a support, at least
one hydrophilic colloidal layer which comprises light-sensitive
silver halide grains having an average grain size of 0.05 - 1.5
and at least 75~ of the total grains being within a range of
0.6 - 1.4 times iarger than the average grain size) a tetrazolium
compound and a sensitizing dye, after the image exposure, with a
hydroquinones-containing developing solution.
According to a preferred embodiment of the invention,
there is obtained a high contrast silver image with a development
stability and a superior reproducibility of the line image by
processing a light-sensitive silver halide pho-tographic material
containing silver halide grains having the above-mentioned grain
size and the distribution thereof (hereinafter referred to as the
silver halide of the invention), a diffusible tetrazolium compound
and a sensitizing dye, after the image exposure, with a hydro-
quinones-containing developing solution.
According to another preferred embodiment of the
invention, there is obtained a dot-image ~half tone image) with
a superior development stability and a superior dot quality by
developing a light-sensitive silver halide photographic material
containing the silver halide of the invention and a non-diffusible
tetrazolium compound and a sensitizing dye, after the image
exposure through a contact screen, with the Metol/hydroquinone
developing solution (hereinafter referred to as the MQ developing
solution) or with the phenidone-hydroquinone developing solution
(hereinafter referred to as the PQ developing solution) which are
.. i .
famous and polular for the black and white developing solution.
It can not be expected fxom heretofore known techniques
that the high contrast line- or dot-image could be obtained
without employing -the infectious developing solution.
As explained above, the tetrazolium compounds include
non-diffusible and diffusi~le ones. The term "non-diffusible
tetrazolium compound" means a compound which does not dissolve
from the light-sensitive material to the developing solution
during the development. In other words, the compound does not
dissolve in a concentration of several ~, preferably not more
than 2%, when a yelatin layer containing the compound is dipped
for 10 minutes in an aqueous solution at 20 - 40C having the
same ion strength and pH-value as those of the developing
solution.
The representative tetrazolium compounds employed in
the invention include the following compounds repres~nted by
the general formulae:
R~ N R3 ( )n-l
N~ c~N (I)
_ R2 _
R4- ~ - N - D I 1l 5 2 (~) n-l
N~C~ ~C~ (II)
R6 7
R8_ ~ _ I Rg R10-NI 1l Rll 2 (~) n-l
C~ ~C/ (III)
E t
In the above formulae, Rl, R3, R4, R5, 8' 9 10
and Rll each represent a group selected from an aryl group
such as a phenyl group (e.g. phenyl, tolyl, hydroxyphenyl,
carboxyphenyl, aminophenyl or mercaptophenyl, carboxyethyl,
nitrophenyl, ethoxyphenyl, iodophenyl, methoxyphenyl, cyano-
phenyl, acetoamidophenyl, etc.), a naphtyl group (e.g. an ~-
naphtyl, ~-naphtyl, hydroxynaphthyl, carboxynaphthyl or amino-
naphthyl, etc.); and a heterocyclic group (e.g. a thiadiazolyl,
benzothiadiazolyl, oxazolyl, pyrimidinyl or pyridyl group, 2,5-
dimethyl thiazolyl, etc.); the groups can advantageously containan electron sharing group capable of forming a metal chelate or
a complex such as primary, secondary, tertiary amino, oxime,
thioether, keto, thioketo, hydroxyl, mercapto, carboxyl, sulfo,
phospho, and al~oxyl; R2, R6 and R7 represent each a group
selected from an aryl group such as a phenyl group and a naphthyl
group, a heterocyclic group, an alkyl group (e.g. methyl, ethyl,
propyl, butyl, mercaptomethyl or mercaptoethyl and a carboxyalkyl
group such as methoxycarbonyl or ethoxycarbonyl), hydroxyl,
carboxyl or the salt thereof, an amino group (e.g. amino, e`thyl-
amino or anilino), mercapto, nitro and hydrogeni D represents adivalent aromatic group; E represents a group sele~te~ from an
alkylene group, an arylene group and an aralkylene group; X is
anion; and n is 1 or 2, provided that the compound forms an intra-
molecular salt when n is 1.
In the above formula, the divalent aromatic group for E
is preferably an arylene group (e.g. phenylene, alkoxy-substituted
phenylene such as methoxy-substituted phenylene, naphtylene
diphenylene, etc.) or a divalent aromatic heterocyclic group. ;~
The following are typical examples oE the cationic
moieties of the tetra~olium compounds represented by the formula
but not intended to limit the tetrazolium compound thereof.
(1) 2-(Benzothiazol-2-yl)-3-phenyl-5-dodecyl-2H-tetrazolium
(2) 2,3-Diphenyl-5-(4-t-octyl~xyphenyl)-2H-tetrazolium
(3) 2,3,5-Triphenyl-2EI-tetrazolium
(4) 2,3,5-Tri(p-carboxyethylphenyl)-2II--tetrazolium
t5) 2-(Benzothiazol-2-yl)-3-phenyl-5-(o-chlorophenyl)-
2H-tetrazolium
(6) 2,3-Diphenyl-2H-tetrazolium
(7) 2,3-Diphenyl-5-methyl-2H-tetrazolium :
(8) 3-(p-Hydroxyphenyl)-5-methyl-2-phenyl-2H-tetrazolium
(9) 2,3-Diphenyl-5-ethyl-2H-tetrazolium
(10) 2,3-Diphenyl-5-n-hexyl-2H-tetrazolium
(11) 5-Cyano-2,3-diphenyl-2H-tetrazolium
(12) 2-(genzothiazol-2-yl)-5-phenyl-3-(4-tolyl)-2H-tetrazolium
(13) 2-(Benzothiazol-2-yl)-5-(4-chlorophenyl)-3-(4-nitrophenyl)
2H-tetrazolium
(14) 5-Ethoxycarbonyl-2,3-di(3-nitrophenyl)-2H-tetrazolium
(15) 5-Acetyl-2,3-di(p-ethoxyphenyl)-2H-tetrazolium
(16) 2,5-Diphenyl-3-(p-tolyl)-2H-tetrazolium
(17) 2,5-Diphenyl-3-(p-iodophenyl)-2H-tetrazolium
(18) 2,3-Diphenyl-5-(p-diphenyl)-2H-tetrazolium~
(19) 5-(p-Bromophenyl)-2-phenyl-3-(2,4,6-trichlorophenyl)-
2H-tetrazolium
(20) 3-(p-Hydroxyphenyl)-5-(p-nitrophenyl)-2-phenyl-21I-
tetrazolium
(21) 5-(3,4-Dimethoxyphenyl)-3-(2-ethoxyphenyl)-2-(4-methoxy-
phenyl)-2H-tetrazolium
(22) 5-(4-Cyanophenyl)-2,3-diphenyl-2H-tetrazolium
~23) 3-(p-Acetamidophenyl)-2,5-diphenyl-2H-tetrazolium
t24) 5-~cetyl-2,3-diphenyl-2H-tetrazolium
-- 8 --
(25) 5-(Fur-2-yl)-2,3-diphenyl-2EI-tetrazolium
~26) 5-(Thien-2-yl)-2,3-diphenyl-2H-tetrazolium
t27) 2,3-Diphenyl-5-(pyrid-4-yl)-2H-tetrazolium
(28) 2,3-Diphenyl-5-(quinol-2-yl)-2EI-tetrazolium
(29) 2,3-Diphenyl-5-(benzoxazol-2-yl)-2I~-tetrazollum
(30) 2,3-Diphenyl-5-nitro-2H-tetrazolium
~31) 2,2',3,3'-Tetraphenyl-5,5'-1,4-butylene-d.i-(2H-tetrazolium)
(32) 2,2',3,3'-Tetraphenyl-5,5'-p-phenylene-di-(2~-tetrazolium)
(33) 2-(~,5-Dimethylthiazol-2-yl)-3,5-diphenyl-2EI-tetrazolium
(34) 3,5-Diphenyl-2-(triazin-2-yl)-2H-tetrazolium
~35) 2-(Benzothiazol-2-yl)-3-(4-methoxyphenyl)-5-phenyl-2H-
tetrazolium
(36) 2,5-Diphenyl-3-~-naphthyl-2H-tetrazolium
(37) 3,3'-(3,3'-Dimethoxy-4,~'-diphenylene)-2,2',5,5'-
tetraphenyl-di-(2H-tetrazolium)
As the anion moiety, there can be mentioned, e.g. a
: halogen ion, a thiosulfate anion, a su.lfate anion, a thiocyanate
anion, an alkylsulfate anion, a nitrate anion, an acetate anion,
a lower alkyl benzenesulfonate anion for the diffusible tetra~
zolium compound and higher alkylbenzene-sulEonate anion such as
p-dodecylbenzenesulfonate anion, a higher alkylsulfate anion
such as laurylsulfate anion, a dialkylsulfosuccinate anion such
as di~2-ethylhexylsulfosuccinate anion, a polyether alcohol
sulfate anion such as cetylpolyethenoxysulfate anion, a higher
fatty acid anion such as stearic acid anion, and a polymer having :
acid radicals such as polyacrylate anion for the non-diffusible
tetraozlium compound.
Most typical examples of the compounds of the invention
are as follow:
._ g _
~5~ ~
1] Diffusible tetrazolium compound
(1) 2,3,5-Triphenyl-2H-tetrazolium chloride
(2) 2,3,5-Tri(p-carboxyethylph~nyl)-2II-tetrazoliu~ iodide
(3) 2-(Benzothiazol-2-yl)-3-phenyl-S-(o-chlorophenyl)-
211-tetrazolium bromide
(4) 2,3-Diphenyl-2H-tetrazolium thiosulfate
(5) 2,3-Diphenyl-5-methyl-2H-tetrazolium chloride
(6) 3~(p-Hydroxyphenyl)-5-methyl-2-phenyl-2H--tetrazolium
sulfate
10 (7) 2,3-Diphenyl-5-ethyl-2~ tetrazolium chloride
~8) 2,3-Diphenyl-S n-hexyl-2EI-tetrazolium chloride
(9) 5-Cyano-2,3-diphenyl-2H-tetrazolium thiocyanate
(10) 2-(Benzothiazol-2-yl)-5-phenyl-3-(4-tolyl)-2~1-
tetrazolium chloride
(11) 2-(Benzothiazol-2-yl)-5-(4-chlorophenyl)-3-(4-nitrophenyl)-
2H-tetrazolium chloride
(12) 5-Ethoxycarbonyl-2,3-di(3-nitrophenyl)-2EI-tetrazolium
bromide
(13) 5-Acetyl-2,3-di(p-ethoxyphenyl)-2H-tetrazolium chloride
20 (14) 2,5-Diphenyl-3-(p-tolyl)-2H-tetrazolium methylsulfate
(15) 2,5-Diphenyl-3-(p-iodophenyl)-2EI-tetrazolium chlorlde
(16) 2,3-Diphenyl-5-(p-diphenyl)-2H-tetrazolium chloride
(17) 5-(p-Bromophenyl)-2-phenyl-3-(2,~,6-trichlorophenyl)-
2H-te-trazolium chloride
(18) 3-(p-Hydroxyphenyl)-5-methyl-2-phenyl-2H-tetrazolium
chloride
(19) 5-(3,4-Dimethoxyphenyl)-3-(2-ethoxyphenyl)-2-(4-methoxy-
phenyl)-2H-tetrazolium chloride
(20) 5-(4~Cyanophenyl)-2,3-diphenyl-2I-I-tetrazolium chloride
30 (21) 3-(p-Acetamidophenyl)-2,5-diphenyl-2H--tetrazolium chloride
-- 10 --
5~
(22) 5-Acetyl-2,3-diphenyl-2H-tetrazolium chloride
(23) 5-(Fur 2-yl)-2,3-diphenyl-2H-tetrazolium chloride
(24) 5-(Thien-2-yl)-2J3-diphenyl-2H-tetrazolium chloride
(25) 2,3-Diphenyl-5-(pyrid-~-yl)-2~I-tetrazolium nitrate
(26) 2,3-Diphenyl-5-(quinol-2-yl)-2H-tetrazolium chloride
(27) 2,3-Diphenyl-5 (benzoxazol-2-yl)-2H-tetrazolium chloride
(28) 2,3-Diphenyl-5-nitro-2H-tetrazolium methylsulfate
(29) 2,2',3,3'-Tetraphenyl-5,5'-1,4-butylene-di-(2H-tetrazolium
chloride) ~ :-
(30) 2,2',3,3'-~etraphenyl-5,5'-p-phenylene di-(2H-tetrazolium ;
chloride)
(31) 2-(4,5-Dimethylthiazol-2-yl)-3,5-diphenyl-2H-tetrazolium
chloride
(32) 3,5-Diphenyl-2-(triazin-2-yl)-2H-tetrazolium sulfate
(33) 2-(Benzothiazol-2-yl)-3-(4-methoxyphenyl)-5-phenyl-2H-
tetrazolium chloride
(34) 2,5-Diphenyl-3-~-napthyl-2H-tetrazolium chloride
(35) 3,3'-(3,3'-Dimethoxy-4,4'-diphenylene)-2,2',5,5'- ;~
tetraphenyl-di-(2H-tetrazolium chloride)
(36) 5-(3-Methoxyphenyl)-3-(3-trif1.uoromethylphenyl)-2-
phenyl-2~-tetrazolium acetate --
[2] Non diffusible tetrazolium compound
(37) 2-(Benzothiazol-2-yl)-3-phenyl-5-dodecyl-2H-tetrazolium
bromide
(38) 2,3-Diphenyl-5-(4-t-octyloxyphenyl)-2H-tetrazolium
chloride
(39) 2,3,5-Triphenyl-2H-tetrazolium diethylhexylsuccinate
sulfonate
(40) 2,3,5-Tri(p-carboxyethylphenyl)-2H-tetrazolium p-dodecyl-
benzenesulEonate
-- 11 --
$
(413 2-(Benzothiazol-2-yl)-3-phenyl-5-(o-chlorophenyl)-
2H-tetrazolium diethylhexylsuccinate sulfonate
(42) 2,3-Diphenyl-2H-tetrazolium p-octylbenzenesulfonate
(43) 2,3-Diphenyl-5-methyl-211-tetrazolium l`aurylsulfate
(44) 3-(p-Hydroxyphenyl)-5-methyl-2-phenyl-2H-tetrazolium
isopropylnaphthalenesulfonate
(45) 2,3-Diphenyl-5-ethyl-2H-tetrazolium diethylhexylsulfo-
succinate
(46) 2,3-Diphenyl-5-n-hexyl-2H-tetrazolium cetylpolyethenoxy-
sulfate
(47) 5-Cyano-2,3-diphenyl-2H-tetrazolium polyacrylate
(48) 2-(Benzothiazol-2-yl)-5-phenyl-3-(4-tolyl)-2H-tetrazolium
diethylhexylsuccinate sulfonate
(49) 2-(Benzothiazol-2-yl)-5-(4-chlorophenyl)-3-(~-nitrophenyl)-
2H-tetrazolium diethylhexylsuccinate sulfonate
(50) 5-Ethoxycarbonyl-2,3-di(3-nitrophenyl)-2H-tetrazolium
diethylhexylsuccinate sulfonate
(51) 5-Acetyl-2,3-di(p-ethoxyphenyl)-2H-tetrazolium die~hyl-
hexylsuccinate sulfonate
(52) 2,5-Diphenyl-3-(p-tolyl)-2H-tetrazolium p-octylbenzene
sulfonate --
(533 2,5-Diphenyl-3-(p-iodophenyl)-2H-tetrazolium p-octyl-
benzenesulfonate `
(54) 2,3-Diphenyl-5-(p-diphenyl)-2~1-tetrazolium p-octyl-
benzenesulfonate
(55) 5-(p-Bromophenyl)-2-phenyl-3-(2,4,6-trichlorophenyl)-
2H-tetrazolium isopropylnaphthalenesulfonate
(56) 3-(p-Hydxoxyphenyl)-5-(p-nitrophenyl)-2-phenyl-2H-
tetrazolium diethylhexylsuccinate sulfonate
- 12 -
(57) 5-(3,4-Dimethoxyphenyl)-3-(2 ethoxyphenyl)-2-(4-methoxy-
phenyl)-2H-tetrazolium diethylhexylsuccinate sulfonate
(58) 5-(4-Cyanophenyl)-2,3-diphenyl-2H-tetrazolium diethyl-
hexylsuccinate sulfonate
(S9) 3-(p-Acetamidophenyl)-2,5-diphenyl-2H-tetrazolium
laurylsulfate
(60) 5-Acetyl-2,3-diphenyl-2H-tetrazolium diethylhexyl- -
succinate sulfonate
(61) 5-(Fur-2-yl)-2,3-diphenyl-2H-tetrazolium diethylhexyl-
succinate sulfonate :
(62) 5-(Thien-2-yl)-2,3-diphenyl-2H-tetrazolium diethylhexyl-
succinate sulfonate
(63) 2,3-Diphenyl-5-(pyrid-4-yl)-2H-tetrazolium diethylhexyl
succinate sulfonate
(64) 2,3-Diphenyl-5-(quinol-2-yl)-2H-tetrazolium
diethylhexylsuccinate sulfonate
(65) 2,3-Diphenyl-5-(benzoxazol-2-yl)-2H-tetrazolium
diethylhexylsuccinate sulfonate
(66) 2,4-Diphenyl-S-nitro-2H-tetrazolium polyacrylate
(67) 2,2',3,3'-Tetraphenyl-5,5'~1,4-butylene-di-(2H-tetrazolium)
laurylsulfate .
(68) 2,2',3,3'-Tetraphenyl-5,5'-p-phenylene-di-(2H-tetrazolium)
cetylpolyethenoxysulfate
(69) 2-(4,5-Dimethylthiazol-2-yl)-3,5-diphenyl-2H-tetrazolium
polyacrylate
(70) 3,5-Diphenyl-2-(triazin-2-yl)-2H-tetrazolium stearate
(71) 2-(Benzothiazol-2-yl)-3~(4-methoxyphenyl)-5-phenyl-2H-
tetrazolium di-ethylhexylsulfosuccinate
(72) 2,5-Diphenyl-3-~-naphtyl-2H-tetrazolium dodecylsulfate
(73) 3,3'-(3,3'-Dimethoxy-4t4'-diphenylene)-2,2'5,5'-
tetraphenyl~di-(2'-tetrazolium polyacrylate)
(74) 5-(3-Methyloxyphenyl)-3-(3-trifluoromethylphenyl)-2-
phenyl-te-trazolium isopropylnaphthalenesulfonate
(75) 2,3,5-Triphenyl-2H-tetrazolium isopropylnaphthalene-
sulfonate
The non-diffusible or diffusible tetrazolium compounds
according to the invention are thus synthesized by an optional
selection of the anionic and cationic moieties. The non-diffusible
compounds, e.g. 2,3,5-triphenyl-2H-tetrazolium dioctyl-succinate-
sulfonate may dispersed into a gelatin solution by mixing the
respective soluble tetrazolium salt and the gelatin first to
disperse them in the gelatin solution and then by that optimum
anion is admixed thereto thereby to obtain the gelatin solution
dispersed with the non-diffusible, tetrazolium compound as
specifically mentioned in working Examples set forth lates.
Alternatively, crystals of the non-diffusible tetra-
zolium compound purely synthesized may be dissolved in a suitable
solvent such as dimethylsulfoxide and then dispersed in the
gelatin solution.
When the dispersion is not sufficiently homogeneous,
good results may be obtained by exposing the emulslon dispersion
to an ultrasonic wave or by use of a suitable homogenizer
such as Manton-Gaulin homogenizer.
As mentionea above, the tetrazolium compounds of this
invention may be used both in diffusible and non-diffusible orms,
when the silver halide of this invention is employed. However,
the higher contrast image may be obtained by employing the non-
diffusible tetrazolium compounds. Accordingly, it is advantageous
to employ the non-diffusible tetrazolium compound when an especially
- 14 -
superior dot quality is required.
On the other hand, the use of too much high contrast
light-sensitive material sometimes brings about not sufficient
reproduction o~ the line-image, particularly those of fine
letters and lines. In this case, an image with more superior
quality may be obtained by the use of the diffusible tetrazolium
compounds.
According to a preferred embodiment of the invention,
the tetrazolium compound of the invention is incorporated into
a silver halide emulsion layer.
According to another preferred embodiment oE the
invention, the compound is incorporated in a layer adjacent -
directly (or a layer adjacent to said adjacent layer) to the
layer containing the silver halide emulsion.
The above-mentioned compounds of the invention may
preferably be employed in an amount of 0.0001 - 10 mole, more
preferably 0.001 - 1 mole, per mole of the silver halide
contained in the light-sensitive silver halide photographic
material of the inven-tion.
The sensitizing dyes used in this invention mean those
which can extend a sensitive wave length range of the silver
halide outside of its inherent sensitive wave length. Sensitiz
ing dyes used ~or this invention cover those such as cyanines,
merocyanines, hemicyanines, oxonols, hemioxonols or mixed mero-
cyanines. Such dyes are described in e.g. "The cyanine dye and
related compounds" by F. M. ~lamer and "The Theory of Photographic
Process", Third edition by C. E. Kenneth Mees and T. ~1. James.
The sensitizing dyes of this invention may be
concretely expressed by the general formulae LIV~XJ;
^l- - 15
,
,:
~IV,~: " - Z 1
R~ N~=ClI-CH )ml C Ll~L2_L3~--C~CH-CH~j~N-R2
(X~
fvl: z Q- l
Rl-N ( CH=CHt~j~~ C~'
0~ :~
~VI~: ", Z1
N ~ CH CH ) m C ~Ll-L2 ~ C
R -~)N~CH-CH~ C~L1 2~;~
(~) Q-1
Q~1 /C L1 ( L2 L3 ) n1 C~ Q2
O I H
,.
2 0 fIX,~: ,~' ", ~/~\~
Q~l ~,C Ll+L2=L3~;~
~o
~X7: " Z
R1-N~CH=CH~C~L1-L2~ IC \F L1~ 2 3
O R3
~- 2 "
--C=~=CH-CH~ R2 ( ) Q-l
r-~ ~ 16
~ .
5~8~
In which Rl, R2 and R3 each represent an alkyl group
~e.g. methyl, ethyl, propyl, butyl and substituted alkyl
such as chloroethyl, hydroxyethyl, methoxyethyl, acetoxy-
ethyl, carhoxymethyl, carboxyethyl, ethoxycarbonylme-thyl,
sulfoethyl, sulfopropyl, sulfobutyl, ~-hydroxy-~-sulfo-
propyl, sulfatepropyl, allyl, benzyl, etc.) or an aryl
group (e.g. phenyl, carboxyphenyl, sulfophenyl, etc.);
Ll, L2 and L3 each represent a methynyl group including
substituted methynyl (e.g. -CH=, -C(C~I3)=, -C(C2H5)=,
-c(cll2cooH)=r -C(CH2~ )=, -c (C6H5)=, -C(C6N4COOH)=~
etc.); Zl' Z2 and Z3 each represent an atom or atom groups
necessary Eor forming a 5 to 6 membered heterocyclic ring
(e.g. thiazoline, oxazoline, selenazoline, thiazole,
selenazole, oxazole, benzothiazole, benzooxazole, benzo-
quinazole, benzoimidazole, 3,3-dialkyl-indolenine, naphtho-
thiazole, naphthooxazole, naphthoselenazole, thienothiazole,
2-pyridine, 4-pyridine, 2-quinoline, 4-quinoline nucleus
etc.); P and Q each represent cyano, -COOR4, -COR4 or -SO2R~
in which R4 represents an alkyl group; ~urther Ql and Q2
each represent an atomic group necessary for forming a
thiooxazolone ring, a pyrazolone ring, an oxyindole ring,
a barbituric acid, a 2 thiobarbituric acid, a 2,4-oxazoli- ;
dinedione ring, a 2,4-thiazolidinedione ring, a 2,4-imida-
zolidinedione ring, a 2-thio-2,4-oxazolidinedione ring,
a 2-thio-2,4-thiazolidinedione ring, a 2-thio-2,4-selena-
zolidinedione ring, a 2-thio-2,5-thiazolidinedione ring,
a 2-thiohydantoine ring, a 4-oxazolinone ring, a 4-thia- ;~
zolinone ring or a 4-imidazoline ring, etc., the groups
or rings including the substituted; Y represents hydrogen,
amino, alkylamino preferably having 1 to 4 carbon atoms
- 17 -
~s~
(e.g. ethylamino, etc.), dialkylamino preferably having
2 to 8 carbon atoms (e.g. dimethylamino, etc.), halogen
(e g. chlorine or bromine atom, etc.) or an alkyl group
preferably having 1 to 4 carbon atoms (e.g. methyl, etc.);
ml and m2 each represent zero or 1; nl and n2 each
represent 0 or 2; X represents an acid anion (e.g. CQ~ ,
Br~ , ~ , CQ04~ , CH3 ~ S03~ -, C~13S04 ~ C2~15S4
etc.); Q represents 1 or 2 and an intramolecular salt is
formed when Q represents 1.
Typical sensitizing dyes having the above general
formulae according to this invention will be exemplified below
but this is not intended to limit these dyes:
CH = <
(CH2)3S03 C2 5
~ ~ ~ CH = <
(CII2)3S03 (Cll2)3s
'~ < ~D
CH3 C2H5
- 18 -
`
5~
4 ~ S e ~D
CH3 (CII2)3SO~
5. CH3
~ ~ CH=C - CH= < N --3
CH2CH21 3 C2H5
CH
6. 12 5 ~ ~-
/~ \ N '~ n / c ~
cQ (1H2~2COO (CH2)2COOH
~ ~ -C~l=C - CH=<
(CH2)3SO3 (CH2)3SO3H N
8. C~I3
N ~ CH=C - CI-I=<
(CH2)3SO3 (C 2)3 3
_ 19 ~
Q ~ ~ CH=C-- CH= < ,~
~CH2) 4S0(~) (CE12) 4S03Na
10 .
~ S 1 2.H5 5 ~
I~J (1 2) 3 3 (1H2) 3S03H N (C2 5 3
11. C2H5
--~ CH=CH-CH= / --
N N /~ (~
C H ( CH 2 ) 3 S0(~
2 5
12 .
J~ CII= -- CH=<
(C 2) 3 3 (CH2) 3S03H-N~3
- 20
,~CN=C ----CH= ~ ~--C
(C~12) 3SO3 (C112) 3S03H N~ ~
C~ ::
14. C2H5 f2H5
C~ ~ N N ~ ~C~Q
~ I ~CH=CH-CH= ~ li
C,2 J~J~ ~?, N--~ 1 ` C_~
f~ (CH2) 2CHS03Na
(CH2) 2CHs3C113
15. CH3 CH3
CH= [~lC~=< _
2 5 I(~)C2H5
2 0 16 . Cn CH=CH-6~ oe ¦~ ~J~
C 2 5
17 .
~X > -"~ >=S
O
c2~5 C2~15
2 1
CH3-N ~ ~ ~ 5
CH2CH20E
1 9 . ~ :
CH-CH ~ ~ S
C2H5 CH2COOH
10 20. CH~CH20H
CH-CH ~ > S
1 2 3 ~ :
503Na
;~1.
~ CH-CH=CH-CH~ S
: 20 C2H5 CH2CooH
`:
22. :~
CH=CH ~ -N < 3
C2~5 ~ :
CH-3 ~ SO~
~: :
~ ' - -
- 22 - ~
:` ~ : , ` :` i: ,: .
5~
23 .
>CCH-CHcCH-CH lS ~,
2 5 C2H5
24. ;
C2H5-N~=CU C =~ >=CH~
O H C2H5 CH3~;~SO (3
25 .
~-S
CH 3 I S
CH 2--CH=CH 2
20 26. - -
¢~ )=CH-C-- CH~ ~r(3
, C2H5 C2H5
27 .
~LCH~
2H5 CH2COOH
- 23 -
.
28.
U CH=CH ~ ~r~
29.
~CH-CH~
C2~5 ~ '~
CH2-CH=CH2
These compounds of this invention can readily be
synthesized by the methods described in e.g. U. S. Patents
2,213,995, 3,711,288, 2,503,776, 3,576,641, 2,945,763, 3,625,6.98,
etc..
These sensitizing dyes according to this invention may be
incorporated into a hydrophilic colloid containing the silver
halide of this invention and a tetrazolium compound by dissolving
them in water or an organic solvent such as methanol and ethanol,
which is miscible with water in any ratio and they can be used in
single or in combination of two or more.
The incorporation of the sensitizing dyes into said
hydrophilic colloid may be any time during the preparation of
the silver halide emulsion, but is preferred to be generally
after the completion of the second ripening.
The sensitizing dye can be used in an amount of 10 mg
to 1 g~ preferably 30 to 300 mg, per one mole of silver halide.
The iight-sensitive silver halide photographic material
of this invention, in which the sensitizing dye is incorporated,
can shown not only an excellent stability during development but
- 24 -
~$~
also can be sensitized in any preferred spectrum range. In
addition, a super sensitization can be expected by use of a
combination of two or more sensitizing dyes in general.
~s the silver halide employed for the light-sensitive
silver halide photographic material of the invention, there can
be included silver halide used for the conventional silver
halide photographic materials, e.g. silver bromide, silver
chlorobromide, silver iodobromide, silver chloroiodobromide or
silver chloride and the like. The average grain size of the
silver halide in the inven-tion is 0.05 - 1.5 ~, preferably 0.1 -
0.8 ~, and at least 75% grains of the total grains are within
a range of 0.6 - 1.4, preferably 0.7 - 1.3 times larger than
the average grain size. Furthermore, the silver halide comprises ;
silver chlorobromide or chloroiodobromide containing at least 50
mole % silver chloride. The silver halide of the invention hav-
ing the above-mentioned average grain size and the distribution
thereof may be prepared by any known method described, e.g. in
,
U.S. Patents 2,592,250, 3,276,877, 3,317,322, 2,222,264, 3,320,069
and 3,206,313 and in Journal of Photographic Science 12(5),
242-251 (1964). Silver halides prepared by other methods may
also be employed in mixture.
According to the most preferred concrete embodiment of
the invention, the silver halide of the invention is silver
chloroiodobromide or chlorobromide having an average grain size
of 0.1 - 0.5 ~ and at least 80~ grains of the total grains being
within a range of 0.7 - 1.3 times larger than the average grain
size.
The silver halide emulsion of the invention may be
sensitized with various kinds of chemical sensitizers. ~s the
sensitizer, there can be mentioned, for example, activated
-
gelatin, sulfur sensitizers (e.g. sodium thiosulfate, aryl
thiocarbamide, thiourea or aryl isocyanate, etc.), selenium -
sensitizers (e.g. N,N-dimethylserenourea or selenourea, etc.),
reducing sensitizers (e.g. triethylenetetramine or stannic
chloride, etc.) and various noble metal sensitizers represen-ted
by potassium chloroaurite, potassium auriothiocyanate, potassium
chloroaurate, 2-aurosulfobenzothiazole methylchloride, ammonium
chloropalladate, potassium chloroplatinate and sodium chloro-
palladite. The sensitizer may be employed alone, or mixed
together. Ammonium thiocyanate may be auxiliarily employed
when a gold sensitizer is employed.
The silver halide emulsion of the invention may
preferably be stabilized with 5,6-trimethylene-7-hydroxy-s-
triazolo(l,5-a3pyrimidine, 5,6-tetramethylene-7-hydroxy- 9-
triazolo(l,5 a)pyrimidine, 5-methyl-7-hydroxy-s-triazolo-
(1,5-a)pyrimidine, 7-hydroxy-s-triazolo(1,5-a)pyrimidine,
5-methyl-6-bromo-7 hydroxy-s-triazolo(1,5-a)pyrimidine, esters
or salts of gallic acid (e.g. isoamyl gallate, dodecyl gallate,
propyl gallate or sodium gallate), mercaptans (e.g. 1-phenyl-5-
mercaptotetrazole or 2-mercaptobenzothiazole), benzotriazoles
(e.g. 5-bromobenzotriazole or 4-methylbenzotriazole) and
benzimidazoles ~e.g. 6-nitrobenzimidazole). Such stabilizers
are described in, e.g. U.S. Patents 2,444,607, 2,716,062,
3,512,982, 3,34~,596l 3,726,686 and 3,717,465, British
Patent 1,363,921. Furthermore, the silver halide emulsion of
the invention may contain a latent image stabilizer such as a
sulfur-containing amino acid, or a gradation-adjusting agent
such as a cadmium or rhodium salt, described in, e.g. British
Patent 1,343,904 and U.S. Patent 3,821,295
- 26 -
~ ~ 55~3~
It has been known in, e.g. British Patent 775,197
and U.S. Patent 3,488~709, to employ a rhodium or cadmium salt
to increase the contrast of silver halide emulsion. However,
problems still remain when the rhodium salt is employedO For
example, the use of rhodium salt kends to cause an unevenness
of the product due to the minute amount of addition and the
narrow allowable range thereo~ of the salt, and thus makes it
difficult to produce stable photographic material. In case of
the cadmium salt, it has to be added as little as possible from
an ecological viewpoint, for it is washed out by film-processing
and comes finally in~o the environment. The cadmium salts are ~`
known to prevent the metabolism and to be harmful to living
tissues. Cadmium may be detected not only in air but also in
the body of sea animals. As a result of interest in public
health and in the maintenance of normal ecological balance in
view of the toxicity o~ rare metals, including cadmium mentioned
above, the inventors have reached the invention relating to a
novel method to obtain a light-sensitive material with su~fi~ -
ciently high contrast, even in no use of such harmful metals
when the above-mentioned silver halide, tetrazolium compound
and sensitizing dye of the invention are incorporated into the
hydrophilic colloidal layer.
The hydrophilic colloid advantageously employed in
the invention is gelatin. As other hydrophilic colloids than
gelatin, are mentioned, e.g. colloidal albumin, agar, gum arabic
arginic acid, hydrolyzed cellulose acetate,acrylamide, imidated
polyamide, polyvinyl alcohol, hydrolized polyvinyl acetate,
water-soluble polymer described in, e.g~ British Patent 523,661,
U.S. Patents 3,847,620, 3,655,389 and 3,341f332, gelatin
derivatives such as phenylcarbamyI-, acylated- or phthalated-
- 27 -
gelatin described in, e.g. U.S. Patents 2,614,928 and 2,525,753,
or graft-polymerized monomers on gelatin having the ethylene
group and being capable of polym~rization, such as acrylic acid
and the ester thereof, styrene, a methacrylic acid and -the ester
thereof, described in, e.g. U.S. Patents 2,548,520 and 2,831,767.
Such hydrophilic colloids may also be applied to a layer contain-
~ing no silver halide, e.g. an antihalation layer, a protective
layer or a intermediate layer.
The light-sensitive silver halide material of the
invention may be prepared by coating the above-mentioned layer
containing the silver halide, the sensitizing dye and the tetra-
zolium compound of the invention on a suitable photographic
support. As the representative supports employed in the invention
are mentioned, e.g. a baryta paper, a polyethylene-coated paper,
a synthetic polypropylene paper, a glass plate, a cellulose
acetate or cellulose nitrate film, a polyester film such as a
polyethylene terephthalate film, a polyamide film, a polypropylene
film, a polycarbonate film, a polystyrene film and the li]ce. The
supports are`optionally selected depending on the purpose for
which the light-sensitive photographic material is used.
As mentioned above, the light-sensitive silver-halide
photographic material of the invention comprise at least one
hydrophilic colloidal layer, coated on a support, containing a
silver halide o the invention and a sensitizing dye and a
tetrazolium compound.
It is preferable in the light-sensitive material of
the invention that a protective layer having a suitable thickness
is coated. The protective layer is advantageously a gelatin
layer, the thickness of which is preferably 0.1 - 10 ~, more
preferably 0.8 2.0 ~.
28 -
~.
~9i ~ ?~
The presence of the protective layer may act effec-
tively on the stability of the image quality and of the
developing process in this invention. This is presumed
because, the protective layer may have a function to control
adequately the iniltration rate of the hydroquinone/Metol or
phenidone from the processing solution into the light-sensitive
material, or the diffusion rate of the tetrazolium compound
within the light-sensitive material or therefrom to the process-
ing solution. This efect is remarkable when the tetrazolium
compound of the invention is employed. The effect is not so
remarka~lewhenother oxidizing agents than the tetrazolium com-
pound, aescribed in, e.g. German Patent Application D.O.S.
2634666 published on February 7, 1977, are employed.
Various kinds of photographic additives may optionally
be added to the above-mentioned hydrophilic colloid of the
invention, as far as they do not impair the effect of the
invention. As the additives, there can be used, e.g. a gelatin
plasticizer, a hardening agent, a surface active agent, a image
stabilizer, an ultraviolet absorber, an anthistaining agent, a
pH adjuster, an antioxidant, an antistatic agent, a viscosity-
increasing agent, a granularity improving agentl a dye, a mordant,
a brightening agent, a development regulator, a matting agent,
and the like.
Among the additives mentioned above, the following may
particularly and prefPrably be employed: viscosity-increasing
agents and plasticizers, described in U.S. Patents 2,960,404 and
3,767,410, 3,659,~56 and 3,692,753, e.g. a styrene/sodium maleate
copolymer and dextran sulfate~ etc.; hardening agents of an
aldehyde, epoxy, ethyleneimine, active halogen, vinylsulfone,
isocyanate, sulfonic acid ester, carbodiimide, mucochloric acid
~ 29 -
.
5~
or acryloyls, etc.; image stabilizers, e.g. 6,6'-butylidene-
bis(2~t-butyl-4-methylphenol) and 4,4'-methylene-bis(2,6-di-t-
butylphenol), etc.; ultraviolet absorbers, described in, e.g.
U.S. Patent 3,253,921, British Patent 1,309,349, U.S~ Patents
3,533,794 and 3,707,375 and British Patent 1,287,770, particu
larly 2-(2-hydroxy-5-t-butylphenyl)benzotriazole, 2-(2-hydroxy-
3,5-di-t-butylphenyl~benzotriazole, 2-(2-hydroxy-3-t-butyl-5-
butylphenyl)-5-chlorobenzotriazole and 2-(2-hydroxy-3,5-di-t-
butylphenyl)-5-chlorobenzotriazole; surface active agents or
coating aids, emulsifiers, infiltration-improving agents for
processing solution, defoamers, or agents for controlling various
physical proper~ies of the light-sensitive material, described in,
e.g. U.S. Patents 3,026,202 and 3,514,293, British Patents 548,532
and 1,216,389, U.S. Patent 3,726,683, including anionic,cationic,
nonionic and amphoteric compounds; mordants described in, e.g.
U.S. Patents 2,113,381 and 2,548,564; antistaining agents
described in, e.g. U.S. Patents 2,360,210, 2,728,659, 2,732,300
and 3,700,453, particularly 2-methyl-5-hexadecylhydroquinone,
2-methyl-5-sec-octadecylhydroquinone and 2,5-di-t-octylhydro-
quinone, etc.; antistatic agents described in, e.g. U.S. Patents2,882,157, 2j972,535 and 3,573,093 and British Patent 1j378,584
and U.S. Patents 3,549,369, 3,704,128 and 3,663,230; matting
agents described in, e.g. U.S. Patents ~,992,101 and 2,956,884,
British Patent 1,221,980 and British Patent 1,307,373,particu-
larly silica gel having a grain size of 0.5 - 20 ~ and poly-
- methylmethacrylate having a grain size of 0.5 - ~0 ~; developing
promotors, e.g. benzyl alcohol and a polyoxyethylene series
compoùnd which may be added in the processing bath.
In accordance with the process of the invention, there
is obtained a high contrast silver image. The lnvention is
~ - 30 -
there~ore applicable to various fields wherein a high contrast
black and white recording is required. The light-sensitive
material of the invention is, for example, applied preferably
to a printing- or micro- sensitive material. The process of
the invention for forming a lith type photographic image has
superior characteristics which no conventional processes have
reached yet. It is not necessarily elucidated why the high
contrast silver image may be obtained according to the process
of the invention. It is presumed that the semiquinone produced
by oxidation of hydroquinone in the developing solution by the
tetrazolium compound may be accumulated in an abnormally high
concentration near the developed silver. It is said, in general,
that the so-called "infectious phenomenon" does not take place
due to instantaneous removal of the semiquinone or quinones by
sulfonation when the sulfite ions are in a high concentration
in the developing solution. Whereas, in the present process,
it is presumed as if the infectious development takes place at
the position of the exposed silver halide in the gelatin layer
due to predominant supply of the semiquinone.
It is accordingly essential in the process of the
invention to treat with a developing solution containing a
hydroquinones developing agent. The lith type developing
solution (infectious developing solution), however, is not
essentially required as far as the solution is oE hydroquinones
by which high contrast lith type silver image may sufficiently
be obtained even in the presence o~ sulfite ion in a high
concentration. The process of the invention differs apparently
from the conventional processes in that no conventional lith
type developing solution which contains hydroquinone, alkali,
alkali metal bromide, sulfite ion in low concentration, and
- 31 -
as a preserver a condensation product of formaldehyde/sodium
bisulfite or carbonylbissulfite amine is neededr although
the use of such components may of course be possible.
As the hydroquinone type developing agents employed
in the invention are mentioned, e.g. hydroquinone, chloro-
hydxoquinone, bromohydroquinone, isopropylhydroquinone, tolu-
hydroquinone, methylhydroquinone, 2,3-dichlorohydroquinone,
2,5-dimethylhydroquinone, 2,3-dibromohydroquinone, 2,5-
dihydroxyacetophenone, 2,5-diethylhydroquinone, 2,5-di~p-
phenethylhydroquinone, 2,5-dibenzoylaminohydroquinone, and
the like.
The developing solution containing the hydroquinones
developing agent employed in the invention includes not only the
so-called lith type developing agent but also the gradient MQ
and PQ developing solution, the latters of which are advantage-
ously employed in the invention because of the easiness of
preparation and superior preservability. Among these developing
solutions, those which show the superadditivity are preferred.
For example, the developing agents and the additives therefor
described in "The Theory of Photographic Process", Third Edition,
pp 374-378 (1966) are advantageously employed. A preserver like
sulfite salts such as sodium sulfite, potassium sulfite or
ammonium sulfite may jointly be employed in the developing
solution used in the invention without impairing the effect of
the invention; and this is another characteristic of the invention.
The adjustment of pH and giving a bufer function with an alkali
hydroxide, alkali carbonate or amine, or addition of inorganic
development retarder such as potassium bromide or of organic
development retarder such as benzotriazole may optionally be
carried out as in the standard black and white developing solution.
- 32 -
;i5~
In the invention the phrase "treat with a developing
solution containing hydroquinones developing agent" means to -
carry out development of the exposed material of the invention
with the developing solution which satisfies the above-mentioned
conditions, and various modes may be included therein. For
example, the temperature at which development is carried out
is preferably below 50C, more preferably around 30C, and the
time required for devèlopment is generally within 30 minutes,
more preferably within 5 minutes, by which good results are
obtained, in general.
Ater the development, the subsequent processes such
as washing, stopping, stabilizing and fixing are carried out.
If necessary, processes like prehardening and neutralization
and the like may be adopted, but they may optionally be omitted.
The processes may be carried out either by the so-called manual
treatment like a bath- or tray-development or by the mechanical
treatment like a roller- or hanger-development. ~ccording to a
preferred embodiment of the invention, the processing solution
in the bath development was more than 20 times more stabler over
long period than the conventional lith type developing solution.
Especially, when the known particular developing sol~tion
containing-sulfite ion in an extremely low concentration is
employed in order to improve the dot quality of the lith type
light-sensitive material, it became of no use for several hours.
While, according to a preferred method of the invention, the
processing solution could be stably employed after one month
has passed, and the dot quality using the solution was then
comparable to that using a newly prepared solution.
Furthermore, addition of a contrast agent often used
for the conventional high contrast developing solution to
_ 33 _
.
the developing solution employed in the invention gives no
undesirable in1uence on the photographic quality.
As can be clearly understood by the explanations
given above, the invention relates to a novel light-sensitive
silver halide photographic material and the processing method
thereof which may obtain a superior stable line- or dot image
by processing the light-sensitive silver halide photographic
material comprising a sensitizing dye, a tetrazolium salt and
a silver halide having a narrow grain size distribution, with
a developing solution containing hydroquinone, using no
infectio~s developing solution.
According to the process of the invention, there is
obtained a stable high con~rast silver image even when the
diffusible tetrazolium compound is employed. There may also
be obtained a stable dot image which is superior to that
obtained by the method described in German Patent Application
D.O.S. 2634666 published on ~ebruary 7, 1977, when the non-
diffusible tetrazolium compound is employed.
The invention is further concretely explained by the
following Examples, which by no means restrict the scope of
the invention and various many modified embodiments may be
possible: .
Example l
A silver chlorobromide-gelation emulsion in fine grain
size state containing silver halide of 90 mole ~ of silver chlo-
ride, 9 mole % of silver bromide and 1 mole % of silver iodide
was chemically sensitized with a sulfur and gold sensitizing
agent. This emulsion had an average grain size of 0.25 ~ and
75% of the whole grains were within a range of 0.19 to 0.31
in grain size. To this emulsion 8 g o 2,3,5-triphenyltetrazolium
~ ~ 3~ ~
chloride per one mole of silver and the equimolar amount of
diethylhexylsuccinate sulfonate (hereintoafter, referred to
as DES) were added. This emulsion was coated on a polyethylene
telephthalate support so as to contain 53 mg of silver/100 cm2
~nd 50 mg of gelatin/100 cm . Next, this pho-tographic element
was wedge-exposed through a gray contact screen of intermediate
tone with a tungsten lamp and processed by the following treat-
ments at 30C.
Development 1.5 minutes
Water washing 1 "
Fixing 2 "
Water washing 5 "
Drying.
The following composition were employed in the
processing bath:
[Developing solution~ ~,
Metol 3.5 g
~nhydrous sodium sulfite 60 g
Hydroquinone 9.0 g
Sodium carbonate 54 g
Potassium bromide 2.5 g --
5-Nitrobenzimidazole 0.5 g
l-Phenyl-5-mercapto-
tetrazole 10 mg
Water to make 1 litre (pH=10 D 25)
[Fixing solution]
Ammonium thiosulfate
decahydrate 150 mg
- Anhydrous sodium sulfite 10 g
Sodium acetate trihydrate . 15 g
35 -
~5~'~'$
Glacial acetic acid 15 mQ
Water to make 1 liter (pH=6.80)
"Dot quality" here in the examples of this invention means
an estimated value of reproduced halftone dot images.
Halftone images obtained rom the exposed and then developed
lith type light-sensitive photographic material are composed
of the part called generally "shadow dot" and the part known
as "highlight part". There is an intermediate part of various
areas in size between both the ends. "Dot quality" here means
an evaluated value of the dot in the part having 50 ~ dot in
which a half of a definite area is clear and the rest of it is
a developed image and the dot quality is expressed in progressive
scale. That is~ 11411 means excellence and "1" extremely badness.
The dot quality below 3 can not be generally permitted.
To this emulsion was incorporated ~xemplified
sensitizing dye No. 14 dissolved in methanol in an amount of
200 mg per one mole of silver (Sample 2).
The results obtained are shown in Table 1.
- 36 -
.5~
Table 1
_
Sensitiæing Development Relative F Dot
Sample dyetime(s) sensitivity og quality
No addition 60 60 0.01 3.0
of the dye 80 100 0.02 3.7
1 (outside of .
this 100 120 0.03 3.3
. invention) 120 130 0.04 3.0
_ _
0.01 3.3
Compound No. 14 _
0.02 3.7
2 (within this _
100 100 0.02 3.7
. invention) . _
120 110 0.02 3.3
_
Table 1 shows that the light-sensitive material
according to this invention does not vary in specific sensitivity
and fog with the development time compared with other materials
than this invention and the variation of dot quality is also
small.
Example 2
A silver halide emulsion was prepared which comprises
a silver chlorobromide emulsion containing silver halide of 60 :
mole % of silver chloride and 40 mole % of silver bromide and
of which the average grain size is 0.3 ~ and 75% of the whole
grains is within a range of 0.24 to 0.37 ~.
To this emulsion hexaamminecobalt (III) trichloride
was added in amount of 4.0 g per one mole of silver. After
the sensitizing dye No. 10 was added in an amount of 200 mg
per one mole of silver, the emulsion was coated on a polyethylene
terephthalate support so as to contain 55 mg of silver per 100 cm2
and 30 mg of gelatin per 100 cm2 and dried.
~ 37 - :
.
(Sample 3)
Next, a similar sample was prepared as above except
that 3.0 g of 2.5-diphenyl-3-~~napthtyltetrazolium chloride (35)
was added instead of hexaamminecobalt (III) -trichloxide
~Sample 4)
These samples were treated in the same way as in
Example 1 together with Sample 5 containing no oxidant.
The results are shown in Table 2.
Table 2
` :~
Development Relative Fo Dot
Sample time(s) sensitivity g quality
_ _
Sample 3 60 30 _ 2.0
0.01 2.3
(outside of
this 100 80 0.01 2.5
invention) 120 150 0.02 2.0
. 60 80 0.01 2.7
Sample 4 .
100 0.01 3.5
. _
. ~within this 100 110 0.01 3.3 ~:
invention) _ :~
120 130 0.01 3.0
sa~ple 5 60 130 0.03 bad
. 80 180 0.07 ." ~"~
(outslde of
. _ ._
this ` 100 220 0.10 : :
invention) 120 280 0.20 _
Table 2 shows that Sample 4 of this invention has an excellent
dot quality compared with Samples 3 and 5.
Example 3
A silver halide emulsion which comprises a silver
bromide emulsion, in which the average grain size is 0.25 ~ and
about 75% of the whole grains is within a range of 0.19 to 0O31 ~,
- 38 -
was chemically sensitized with a gold sensitizer. Into this
emulsion was added 4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene
in an amount of 500 mg per one mole of silver. This emulsion
was coated on a polyethylene tereph-thalate film supp~rt in
an amount of 50 mg of silver per 100 cm2 and dried. In this
case, the following compounds were added after chemical ripening
to obtain the following samples.
Sample 6: Hexaamminecobalt (III) isopropylnaphthalenesulfonate
was added to this emulsion in an amount of 5.0 g per one mole
of silver.
Sample 7: Compound No. 12 of the sensitizing dye was added
to Sample 6 in an amount of 220 mg per one mole of silver.
Sample 8: This sample was prepared in the same way as in
Sample 7 except that 2,3,5-triphenyl-2H-tetrazolium isopropyl-
naphthalenesulfonate (tetrazolium Compound (75)) was added in
the same mole amount instead of hexaamminecobalt ~III) isopropyl-
naphthalenesulfonate.
Sample 9: Tartrazine{4,5-dihydro-5-oxo~ sulfonyl)-4-
1(4-sulfonyl)azo~-lH-pyrazole-3-carboxylic acid trisodium salt~
was added to Sample 8 in an amount of 100 mg per one mole of
silver.
These samples were treated in the same way as in Example 1
except that they were developed by the following developing
solution at 30C for 60, 80, 100, 120 and 140 seconds.
Composition of the developing solution
l-~henyl-3-pyrazolidone0.8 g
Anhydrous sodium sulfite 45 g
Potassium hydroxide10 g
Hydroquinone 20 g
Anhydrous sodium carbonate - 20 g
- 39 - -
6-Nitroindazole 0.1 g
Pure water to make 1 Q
The results ohtained are shown in Table 3.
Table 3
Development Relative Dot
Sampletime(s) sensitivity og quality
., _ .
0.01 2.0
0.01 3.0
_
Sample 6100 100 0.02 3.2
. _
120 140 0.03 3.0 ~ :
. 140 170 0.04 2.5
_
0.01 2.5
_ _ _ .
0.01 3.0
_
Sample 7100 95 0.01 3.5
120 107 0.02 3.7
140 120 0.03 3.0
. .
0.00 3.0
_
0.01 3.5
Sample 8100 100 0.01 3.8
_
120 100 0.01 3.8
_
14-0 103 0.01 - 3.5
_
0.00 3.0
. _ ..
OoOl3.5
.
Sample 9 100 97 0.01 4.0
_ _ _ ~
120 102 0.01 4.0
_
140 107 0.01 3.5
_ __
Table 3 shows the following facts: even in the case of using
non-diffusible oxidants except the tetrazolium salt, some
effects could be expected but the use of the tetrazolium salt
.. -- ~0 --
, :
produced remarkable effects. The use of an irradiation
prohibiting dye such as Tartrazine except the sensitizing dye
has some effects for raising the dot quality but has no e~fect
for processing stably the development and giving skable
characteristics as in this invention.
Example 4
In this example the same emulsion as in Example 3
was used and the following compounds were added after the
emulsion was chemically sensitized.
Sample 10: 3-(p-~ydroxyphenyl)-5-methyl-2-phenyl-2H-tetrazolium
chloride (tetrazolium Compound (18)) was added in an amount of !
3.0 g per one mole of silver.
Sample 11: To sample 10 was further added Compound No. 23 of
the sensitizing dye in amount of 150 mg per one mole of silver.
These sample were treated with the same development
process as in Example 1 except that they were developed for 80,
100, 120 and 140 seconds.
The results obtained are shown in Table 4.
Table 4
Sample time(s) sensitivity Fog _ quality
0.004.0 2.0
. ,
100 87 0.018.0 2.7 ~ ,
Sample 10
120 1~0 0.0310.0 3.0
140 135 0.059 3 2.7
_80 0.017.0 2.5
100 100 0.0110.0 3.0
Sample 11 _ _
120_ 107 ~.0210.0 3.0
_ ~40112 0.039 5 3.0
- 41 -
, .
Table 4 shows that the sample, in which the sensiti~ing dye was
added, has a higher stabili~y during the development process than
that having no addition.
Example 5
This sample was p~epared in the same way as in
Example 4 using the dye compound No. 23 so as to have an average
grain size of 0.25 ~ by mixing single diffraction emulsions hav-
ing 0.015 ~ and 0.035 ~ at peaks. :
The results obtained are shown in Table 5.
Table 5
_ _ .
Sensitizing Development Relative Fo Dot
dye time(s) sensitivity g quality
0.011.5
100 0.022.0
No addition
100 130 0.032.5 ~ :
_ .
120 ` 150 0.04_1.5 _
0.011.5 :
. 200 mg of Compound .
110 0.022.0
23 was added per
one mole of 100 137 0.032.7
silver ~
120 155 0.032.0 ~:
'
2Q Table 5 shows that sufficient effects can not obtained whenthe grain size distribution is wider than the scope of that
of this invention. ~:
.
,
- 42 -
.. ..
