Title: Silver halide photosensitive material
Abstract: A silver halide photosensitive material comprises a light-sensitive silver halide emulsion layer on a support. The photosensitive material has a layer comprising an emulsified dispersion containing a surfactant represented by formula (I), and an emulsion containing tabular silver halide grains having an average aspect ratio of 8 or greater, and at least one sensitizing dye.
(R1-L
##CHR1##
A)m General formula (I)
wherein A represents an acid group or a metal salt thereof, R1 represents an aliphatic group containing a linear aliphatic group having 6 or more carbon atoms as a partial structure thereof and having the total number of carbon atoms of 17 or more, L represents a bivalent group, J represents a linking group of n+m valence, n is an integer of 1 to 6, and m is an integer of 1 to 3. The molecular weight of surfactant of the formula (I) divided by m is 430 or greater.
Patent Number: 6,994,953 Issued on 02/07/2006 to Matsuda, et al.
| Inventors:
|
Matsuda; Naoto (Minami-Ashigara, JP);
Miyamoto; Yasushi (Minami-Ashigara, JP);
Yasuda; Tomokazu (Minami-Ashigara, JP)
|
| Assignee:
|
Fuji Photo Film Co., Ltd. (Kanagawa, JP)
|
| Appl. No.:
|
921963 |
| Filed:
|
August 20, 2004 |
Foreign Application Priority Data
| Aug 22, 2003[JP] | 2003-298541 |
| Current U.S. Class: |
430/631; 430/567; 430/634; 430/635; 430/570; 430/546; 430/502 |
| Current Intern'l Class: |
G03C 1/00.5 (20060101); G03C 1/49.4 (20060101) |
| Field of Search: |
430/567,631,634,635,570,546,502
|
References Cited [Referenced By]
| Foreign Patent Documents |
| 0182658 | May., 1986 | EP.
| |
| 61-184542 | Aug., 1986 | JP.
| |
| 480751 | Mar., 1992 | JP.
| |
Primary Examiner: Letscher; Geraldine
Attorney, Agent or Firm: Sughrue Mion, PLLC
Claims
What is claimed is:
1. A silver halide photosensitive material comprising at least one light-sensitive
silver halide emulsion layer on a support, wherein the silver halide photosensitive
material has
at least one layer comprising an emulsified dispersion containing at least one
surfactant represented by general formula (I), and
at least one emulsion containing tabular silver halide grains having an average
aspect ratio of 8 or greater, and at least one sensitizing dye.
(R
1-L
##CHR23##
A)
m General formula (I)
wherein A represents an acid group selected from the group consisting of sulfonic
acid, phosphoric acid and carboxylic acid groups, or a metal salt thereof, R
1
represents an aliphatic group containing a linear aliphatic group having 6 or more
carbon atoms as a partial structure thereof, L represents a bivalent group, J represents
a linking group of n+m valence which links R
1-L with A, n is an integer
of 1 to 6, and m is an integer of 1 to 3,
provided that when n is 1, the total number of carbon atoms of R
1
is 17 or greater, and when n is 2 or greater, the total number of carbon atoms
of all the R
1 is 17 or greater and the plurality of R
1-L's
may be the same or different,
that when m is 2 or greater the plurality of A's may be the same or different,
and
that when A is an acid group, the quotient of the molecular weight of surfactant
of the general formula (I) divided by m is 430 or greater, and when A is a salt
of metal atom, the molecular weight of the surfactant of the general formula (I)
after substitution of the metal atom with hydrogen atom, divided by m is 430 or
greater.
2. A silver halide photosensitive material comprising at least one light-sensitive
silver halide emulsion layer on a support, wherein the silver halide photosensitive
material has
at least one layer comprising an emulsified dispersion containing a surfactant
represented by general formula (I), and
at least one emulsion containing tabular silver halide grains having an average
equivalent sphere diameter of 0.55 μm or less and having an average aspect
ratio of 2 or greater, and at least one sensitizing dye.
(R
1-L
##CHR24##
A)
m General formula (I)
wherein A represents an acid group selected from the group consisting of sulfonic
acid, phosphoric acid and carboxylic acid groups, or a metal salt thereof, R
1
represents an aliphatic group containing a linear aliphatic group having 6 or more
carbon atoms as a partial structure thereof, L represents a bivalent group, J represents
a linking group of n+m valence which links R
1-L with A, n is an integer
of 1 to 6, and m is an integer of 1 to 3,
provided that when n is 1, the total number of carbon atoms of R
1
is 17 or greater, and when n is 2 or greater, the total number of carbon atoms
of all the R
1's is 17 or greater and the plurality of R
1-L's
may be the same or different,
that when m is 2 or greater the plurality of A's may be the same or different,
and
that when A is an acid group, the quotient of the molecular weight of surfactant
of the general formula (I) divided by m is 430 greater, and when A is a salt or
metal atom, the molecular weight of the surfactant of the general formula (I) after
substitution of the metal atom with hydrogen atom, divided by m is 430 greater.
3. A silver halide photosensitive material comprising at least one light-sensitive
silver halide emulsion layer on a support, wherein
the silver halide photosensitive material has at least one layer comprising an
emulsified dispersion containing a surfactant represented by the following general
formula (I), and
a total amount of spectral sensitizing dyes contained in the silver halide photosensitive
material is in the range of 18 to 200 mg/m
2
(R
1-L
##CHR25##
A)
m General formula (I)
wherein A represents an acid group selected from the group consisting of sulfonic
acid, phosphoric acid and carboxylic acid groups, or a metal salt thereof, R
1
represents an aliphatic group containing a linear aliphatic group having 6 or more
carbon atoms as a partial structure thereof, L represents a bivalent group, J represents
a linking group of n+m valence which links R
1-L with A, n is an integer
of 1 to 6, and m is an integer of 1 to 3,
provided that when n is 1, the total number of carbon atoms of R
1
is 17 or greater, and when n is 2 or greater, the total number of carbon atoms
of all the R
1's is 17 or greater and the plurality of R
1-L's
may be the same or different,
that when m is 2 or greater the plurality of A's maybe the same or different,
and
that when A is an acid group, the quotient of the molecular weight of the surfactant
of the general formula (I) divided by m is 430 greater, and when A is a salt of
metal atom, the molecular weight of surfactant of the general formula (I) after
substitution of the metal atom with hydrogen atom, divided by m is 430 or greater.
4. The silver halide photosensitive material according to claim 1, wherein the
surfactant represented by the general formula (I) is one represented by general
formula (II):
(R
1-L
2##CHR26##
kJ-SO
3M General
formula (II)
wherein R
1 is as defined in claim 1, L
2 represents a bivalent
group selected from —O—, —CO— and —O—CO—,
wherein —O—CO— is bonded with R
1 at the left side
thereof, k is 2 or 3, J represents a linking group of k+1 valence, provided that
the J group does not contain any aryl group, and M represents a hydrogen atom or
a metal atom,
provided that the total number of carbon atoms of R
1's in the moiety
of (R
1-L
2)
k is 17 or greater, and
that when M is a hydrogen atom the molecular weight of surfactant of the general
formula (II) is 430 greater, and when M is a metal atom the molecular weight of
surfactant of the general formula (II) after substitution of the metal atom with
a hydrogen atom, is 430 or more.
5. The silver halide photosensitive material according to claim 1, wherein the
surfactant represented by the general formula (I) is used in an amount of at least
20% by weight of all the surfactants used in the silver halide photosensitive material.
6. The silver halide photosensitive material according to claim 1, wherein the
average aspect ratio of the tabular silver halide grains is 10 or more.
7. The silver halide photosensitive material according to claim 1, wherein the
weight ratio, in terms of silver, of the tabular silver halide grains is 30% or
more of the total amount of silver halide grains contained in the silver halide
photosensitive material.
8. The silver halide photosensitive material according to claim 1, wherein the
total amount of spectral sensitizing dyes contained in the silver halide photosensitive
material is 18 mg/m
2 to 200 mg/m
2.
9. The silver halide photosensitive material according to claim 1, wherein the
silver halide photosensitive material further comprises, in addition to the emulsion
containing tabular silver halide grains having an average aspect ratio of 8 or
greater, at least one emulsion containing tabular silver halide grains having an
average equivalent sphere diameter of 0.55 μm or less and having an average
aspect ratio of 2 or greater, and at least one sensitizing dye.
10. The silver halide photosensitive material according to claim 9, wherein the
total weight of grains, in terms of silver, of the emulsion containing tabular
silver halide grains having an average aspect ratio of 8 or greater, and the emulsion
containing tabular silver halide grains having an average equivalent sphere diameter
of 0.55 μm or less and having an average aspect ratio of 2 or greater, is
50% or more of the total amount of silver halide grains contained in the silver
halide photosensitive material.
11. The silver halide photosensitive material according to claim 2, wherein the
surfactant represented by the general formula (I) is one represented by general
formula (II):
(R
1-L
2##CHR27##
kJ-SO
3M General
formula (II)
wherein R
1 is as defined in claim 2, L
2 represents a bivalent
group selected from —O—, —CO— and —O— CO—,
wherein —O——CO— is bonded with R
1 at the left
side thereof, k is 2 or 3, J represents a linking group of k+1 valence, provided
that the J group does not contain any aryl group, and M represents a hydrogen atom
or a metal atom,
provided that the total number of carbon atoms of R
1's in the moiety
of (R
1-L
2)
k is 17 or greater, and
that when M is a hydrogen atom the molecular weight of surfactant of the general
formula (II) is 430 greater, and when M is a metal atom the molecular weight of
surfactant of the general formula (II) after substitution of the metal atom with
a hydrogen atom, is 430 or more.
12. The silver halide photosensitive material according to claim 2, wherein the
surfactant represented by the general formula (I) is used in an amount of at least
20% by weight of all the surfactants used in the silver halide photosensitive material.
13. The silver halide photosensitive material according to claim 2, wherein the
average equivalent sphere diameter of the tabular silver halide grains is 0.50
μm or less.
14. The silver halide photosensitive material according to claim 2, wherein the
weight ratio, in terms of silver, of the tabular silver halide grains is 30% or
more of the total amount of silver halide grains contained in the silver halide
photosensitive material.
15. The silver halide photosensitive material according to claim 2, wherein the
total amount of spectral sensitizing dyes contained in the silver halide photosensitive
material is 18 mg/m
2 to 200 mg/m
2.
16. The silver halide photosensitive material according to claim 3, wherein the
surfactant represented by the general formula (I) is one represented by general
formula (II):
(R
1-L
2##CHR28##
kJ-SO
3M General
formula (II)
wherein R
1 is as defined in claim 3, L
2 represents a bivalent
group selected from —O—, —CO— and —O—CO—,
wherein —O—CO— is bonded with R
1 at the left side
thereof, k is 2 or 3, J represents a linking group of k+1 valence, provided that
the J group does not contain any aryl group, and M represents a hydrogen atom or
a metal atom,
provided that the total number of carbon atoms of R
1's in the moiety
of (R
1-L
2)
k is 17 or greater, and
that when M is a hydrogen atom the molecular weight of surfactant of the general
formula (II) is 430 greater, and when M is a metal atom the molecular weight of
surfactant of the general formula (II) after substitution of the metal atom with
a hydrogen atom, is 430 or more.
17. The silver halide photosensitive material according to claim 3, wherein the
surfactant represented by the general formula (I) is used in an amount of at least
20% by weight of all the surfactants used in the silver halide photosensitive material.
18. The silver halide photosensitive material according to claim 3, wherein the
total amount of spectral sensitizing dyes contained in the silver halide photosensitive
material is 20 mg/m
2 to 80 mg/m
2.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority from prior
Japanese Patent Application No. 2003-298541, filed Aug. 22, 2003, the entire contents
of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a silver halide photosensitive material.
2. Description of the Related Art
In silver halide color photosensitive materials, sensitizing dyes are added to
photo-sensitive silver halide emulsion grains so as to effect spectral sensitization
in desired wavelength regions of blue, green and red, optionally including infrared.
The thus added sensitizing dyes are ordinarily unnecessary in images after development
processing, and it is preferred under normal conditions that the whole amount of
sensitizing dyes flow out from the photosensitive material or be decolorized during
the development processing. However, in actual color photosensitive materials,
portions of the sensitizing dyes occasionally do remain even after the development processing.
When the remaining of sensitizing dyes occurs in, for example, color reversal
film photosensitive materials, coloring is likely to be conspicuous in white background
areas of images. Thus, in color film designing, it is preferred to suppress the
remaining of sensitizing dyes.
On the other hand, in color films of recent years, measures comprising using
silver
halide emulsion grains in tabular form so as to achieve an increase of surface
area and loading the increased surface with a large amount of sensitizing dyes
so as to attain a sensitivity enhancement, are increasingly employed. These measures
naturally increase the amount of sensitizing dyes remaining after the development
processing, thereby deteriorating the quality of color film. Therefore, there is
a demand for a technique capable of reducing the amount of remaining sensitizing
dyes. Such a technique capable of reducing the amount of remaining sensitizing
dyes has become especially important in the recent technical trend comprising increasing
the aspect ratio of tabular silver halide grains as a source for sensitivity enhancement.
BRIEF SUMMARY OF THE INVENTION
The inventors have conducted extensive and intensive studies with respect to
the residue of sensitizing dyes in color films. As a result, it has been found
that the residual amount of sensitizing dyes can be reduced by the use of specified
surfactants at the emulsification dispersion of photographically useful materials
such as image forming couplers.
With respect to surfactants, although examples of the effects thereof on the
enhancement of image fastness (see, for example, Jpn. Pat. Appln. KOKAI Publication
No. (hereinafter referred to as JP-A-) 61-184542) and examples of the effects thereof
on the enhancement of color formation capability and image fastness (see, for example,
JP-A-4-80751) have been disclosed, the effect thereof on the residue of sensitizing
dyes has been unknown.
It is a primary object of the present invention to provide a method of reducing
the amount of sensitizing dyes remaining after the development processing in the
field of silver halide photosensitive materials. It is a further object of the
present invention to provide a silver halide photosensitive material of high speed
that ensures less coloring in white background areas of images, realizing excellent
storability especially in heat and humidity.
The objects of the present invention have been attained by the following.
(1) A silver halide photosensitive material comprising at least one light-sensitive
silver halide emulsion layer on a support, wherein the silver halide photosensitive
material has
at least one layer comprising an emulsified dispersion containing at least one
surfactant represented by the following general formula (I), and
at least one emulsion containing tabular silver halide grains having an average
aspect ratio of 8 or greater, and at least one sensitizing dye.
(R
1-L
##CHR2##
A)
m General formula (I)
In the formula, A represents an acid group selected from sulfonic acid, phosphoric
acid and carboxylic acid groups, or a metal salt thereof. R
1 represents
an aliphatic group containing a straight-chain aliphatic group having 6 or more
carbon atoms as a partial structure thereof. L represents a bivalent group. J represents
a linking group of n+m valence which links R
1-L with A. n is an integer
of 1 to 6, and m is an integer of 1 to 3. When n is 2 or greater, the plurality
of R
1-L's may be the same or different. When m is 2 or greater, the
plurality of A's may be the same or different. Provided that the total number of
carbon atoms of R
1 (when n is 2 or greater, the total number of carbon
atoms of all the R
1's) is 17 or greater, and that the quotient of the
molecular weight of surfactant of the general formula (I) (with respect to a salt
of metal atom, molecular weight after substitution with hydrogen atom) divided
by m is 430 or greater.
(2) A silver halide photosensitive material comprising at least one light-sensitive
silver halide emulsion layer on a support, wherein the silver halide photosensitive
material has
at least one layer comprising an emulsified dispersion containing a surfactant
represented by the following general formula (I), and
at least one emulsion containing tabular silver halide grains having an average
equivalent sphere diameter of 0.55 μm or less and having an average aspect
ratio of 2 or greater, and at least one sensitizing dye.
(R
1-L
##CHR3##
A)
m General formula (I)
wherein A, R
1, L J, m and n are as defined in (1) above.
(3) A silver halide photosensitive material comprising at least one light-sensitive
silver halide emulsion layer on a support, wherein
the silver halide photosensitive material has at least one layer comprising an
emulsified dispersion containing a surfactant represented by the following general
formula (I), and
the total amount of spectral sensitizing dyes contained in the silver halide
photosensitive material is in the range of 18 to 200 mg/m
2.
(R
1-L
##CHR4##
A)
m General formula (I)
wherein A, R
1, L J, m and n are as defined in (1) above.
Additional objects and advantages of the invention will be set forth in
the description which follows, and in part will be obvious from the description,
or may be learned by practice of the invention. The objects and advantages of the
invention may be realized and obtained by means of the instrumentalities and combinations
particularly pointed out hereinafter.
DETAILED DESCRIPTION OF THE INVENTION
The surfactants represented by the general formula (I) will be described in detail below.
First, A of the general formula (I) will be described. A represents an acid
group selected from sulfonic acid, phosphoric acid and carboxylic acid groups,
or a metal salt thereof. Preferably, A represents a sulfonic acid or phosphoric
acid group. More preferably, at least one of A's represents a sulfonic acid group
or a metal salt thereof. When a metal salt is represented, the metal atom is preferably
an alkali metal (e.g., lithium, sodium or potassium) or an alkaline earth metal
(e.g., magnesium or calcium). Most preferably, the metal atom is lithium, sodium
or potassium. The bonding between A and J is effected at a carbon atom when A is
a carboxylic acid. When A represents sulfonic acid or phosphoric acid, the bonding
may be effected at a sulfur atom or phosphorus atom, or may be effected via an
oxygen atom.
R
1 represents an aliphatic group containing a linear aliphatic
group having 6 or more carbon atoms as a partial structure thereof. The above linear
aliphatic group having 6 or more carbon atoms may be, for example, a saturated
linear alkyl group such as n-octyl or n-dodecyl, or may be a linear group having
in its molecule an unsaturated bond (the position thereof is not particularly limited,
and when the unsaturated bond is a double bond, its arrangement may be cis or trans)
such as oleyl, or may be a branched alkyl group such as 2-n-hexyl-n-nonyl. The
group R
1 per se may be a linear aliphatic group having 6 or more carbon
atoms. The hydrogen atoms of such aliphatic groups may partially or entirely be
substituted with halogen atoms (e.g., fluorine atom or chlorine atom). A bivalent
group such as oxygen atom may be inserted in the middle thereof. Further, R
1
may be in the form of a polymer comprising, via J, the general formula (I)
as a constituting unit.
Among them, R
1 is preferably an aliphatic group containing an aliphatic
group having 9 or more carbon atoms as a partial structure thereof, more preferably
an aliphatic group containing an aliphatic group having 12 or more carbon atoms
as a partial structure thereof.
Specific examples of these groups include:
n-C
8H
17, n-C
9H
19,
n-C
10H
21, n-C
12H
25, n-C
14H
29,
n-C
16H
33, n-C
18H
37, n-C
20H
41,
2-ethylhexyl, i-C
16H
33, n-C
18H
35 (one
double bond contained in the alkyl chain), CH
3—(CF
2)
4—(CH
2)
4,
CH
3—(CF
2)
8 and C
12H
25—OC
2H
4—.
L represents a bivalent group. As the same, there can be mentioned, for example,
—CHR
2—, —O—, —CO— (bonding may be
effected in either direction), —COO— (bonding may be effected in either
direction), —OCOO—, —CONR
2— (bonding may be
effected in either direction), —NR
2CONR
3—, —SO
2—,
—SO
2NR
2— (bonding may be effected in either direction),
—S—, or substituted or unsubstituted phenylene or naphthalene group.
Each of R
2 and R
3 represents a hydrogen atom or an alkyl.
Among these, L preferably represents —CHR
2—, —O—,
—CO— (bonding may be effected in either direction), —COO—
(bonding may be effected in either direction) or —CONR
2—
(bonding may be effected in either direction).
J represents a linking group. J is not limited as long as it is a group capable
of linking L with A. Examples of the linking forms between L, J and A are as follows.
##STR1##
##STR2##
n is an integer of 1 to 6, preferably 2 to 6.
m is an integer of 1 to 3, preferably 1.
In the surfactants of the general formula (I), the total number of carbon atoms
of R
1 is 17 or greater, preferably in the range of 20 to 70, and more
preferably in the range of 24 to 50.
The quotient of the molecular weight of surfactant of the general formula (I)
divided by m is 430 or greater, preferably in the range of 450 to 1000, and more
preferably in the range of 470 to 900.
Among the surfactants of the general formula (I), the compounds of the following
general formula (II) are preferred.
(R
1-L
2##CHR7##
kJ-SO
3M General
formula (II)
In this formula, R
1 is as defined in the general formula (I). L
2
represents a bivalent group selected from —O—, —CO—
and —O—CO— (bonded with R
1 at the left side of the
formula). k is 2 or 3. J represents a linking group of k+1 valence, provided that
the J group does not contain any aryl group. M represents a hydrogen atom or a
metal atom. Provided that the total number of carbon atoms of R
1 in
the moiety of (R
1-L
2)
k is 17 or greater, and that
the molecular weight of each of the compounds of the general formula (II) (assuming
that M is a hydrogen atom) is 430 or greater.
In the general formula (II), R
1 is preferably a saturated or unsaturated
linear or branched aliphatic group containing at least a linear chain moiety having
9 or more carbon atoms as a partial structure thereof, more preferably a saturated
or unsaturated linear or branched aliphatic group containing at least a linear
chain moiety having 12 or more carbon atoms as a partial structure thereof. The
hydrogen atoms of these may partially be substituted with halogen atoms.
The total number of carbon atoms of R
1 is 17 or greater, preferably
20 or greater and more preferably 24 or greater.
L
2 represents a bivalent group selected from —O—,
—CO— and —O—CO— (bonded with R
1 at the
left side of the formula). L
2 preferably represents —O—
or —O—CO— (bonded with R
1 at the left side of the
formula), most preferably —O—CO— (bonded with R
1 at
the left side of the formula).
J represents a linking group which does not contain any aryl group. J is preferably
an alkylene having 10 or less carbon atoms, or a bivalent group constituted of
an alkylene having 10 or less carbon atoms and an oxygen atom (ether group) (the
oxygen atom may be positioned in the middle of alkylene or at ends thereof), or
the group (J-9) mentioned in the description of J of the general formula (I). More
preferably, J is an alkylene having 8 or less carbon atoms, or a bivalent group
constituted of an alkylene having 8 or less carbon atoms and an oxygen atom (the
oxygen atom may be positioned in the middle of alkylene or at ends thereof), or
the group (J-9). In the (J-5) and (J-9) among the (J-1), (J-2), (J-3), (J-4), (J-5)
and (J-9) mentioned in the description of the general formula (I), j is most preferably
6 or less.
k is 2 or 3, preferably 2.
As other preferred examples of the surfactants represented by the general formula
(I), there can be mentioned those of the following general formulae (III) and (IV).
##STR3##
In the general formulae (III) and (IV), R
1 is as defined in the general
formula (I), and preferred examples thereof are the same as mentioned there.
L
3 represents a bivalent group selected from —CHR
2—,
—O—, —CO—, —COO— (bonding may be effected in
either direction), —OCOO—, —CONR
2— (bonding
may be effected in either direction), —NR
2CONR
3—,
—SO
2—, —SO
2NR
2— (bonding
may be effected in either direction) and —S—. R
2 and R
3
are as defined in the general formula (I).
g is a natural number of 1 to 4, and h is a natural number of 1 to 3.
The compounds of the general formulae (III) and (IV) will be described in detail below.
L
3 preferably represents —CHR
2—,
—O—, —CO—, —COO—, —CONR
2—
(bonding may be effected in either direction) or —SO
2NR
2—
(bonding may be effected in either direction), and more preferably represents —CHR
2—,
—O—, —COO— (bonding may be effected in either direction)
or —CONR
2— (bonding may be effected in either direction).
Each of g and h is preferably 1 or 2. More preferably, g is 2, or g and h are
simultaneously 1.
In the present invention, most preferred surfactants are those of the general
formula (II) wherein R
1 is an aliphatic group containing a linear chain
moiety having 9 or more carbon atoms, the aliphatic group having 10 to 20 carbon
atoms in total; L
2 is —O— or —OOC— (bonded with
R
1 at the oxygen atom); J is an alkylene having 2 to 10 carbon atoms,
or a bivalent group constituted of an alkylene having 2 to 10 carbon atoms and
an oxygen atom; and k is 2 or 3.
Specific examples of the compounds of the general formula (I) will be shown
below, which however in no way limit the scope of the present invention.
##STR4##
##STR5##
##STR6##
##STR7##
The method of adding the surfactant of the present invention to a photosensitive
material may be any one, and preferably, the surfactant may be added at the time
of dissolving photographically useful oil-soluble compounds, such as a coupler,
color-mixing preventing agent and ultraviolet absorbent, and dispersing it by emulsification
to an aqueous solution.
The addition amount of the surfactant of the present invention is preferably
0.01 g to 1.0 g, more preferably 0.05 g to 0.5 g per square meter of the photosensitive
material. Further, when the surfactant of the present invention is used for emulsifying
dispersion, the amount is preferably 1 to 20% by weight, more preferably 1 to 10%
by weight to the total weight of the oil-soluble compounds contained in the emulsified dispersion.
The surfactant of the present invention may be used in combination with another
surfactant. Preferably used surfactants to be used in combination are those mentioned
below, but the surfactants that may be used in combination with the surfactant
of the present invention are not limited to these.
##STR8##
When the surfactant of the present invention is used in combination with other
surfactants, the ratio by weight of the surfactant of the present invention to
the total amount of surfactants contained in the photosensitive material is preferably
20% or greater, more preferably 40% or greater.
When photographically useful oil-soluble compounds are emulsified and dispersed
with the use of the surfactant of the present invention, use can be made of a high-boiling
organic solvent.
Examples of the high-boiling organic solvents which can be employed include
phthalic acid esters (e.g., dibutyl phthalate, dioctyl phthalate, dicyclohexyl
phthalate, di-2-ethylhexyl phthalate, decyl phthalate, bis(2,4-di-tert-amylphenyl)
isophthalate and bis(1,1-diethylpropyl) phthalate), esters of phosphoric acid or
phosphonic acid (e.g., diphenyl phosphate, triphenyl phosphate, tricresyl phosphate,
2-ethylhexyl diphenyl phosphate, dioctyl butyl phosphate, tricyclohexyl phosphate,
tri-2-ethylhexyl phosphate, tridodecyl phosphate and di-2-ethylhexyl phenyl phosphate),
benzoic acid esters (e.g., 2-ethylhexyl benzoate, 2,4-dichlorobenzoate, dodecyl
benzoate and 2-ethylhexyl p-hydroxybenzoate), amides (e.g., N,N-diethyldodecanamide,
N,N-diethyllaurylamide, N,N,N,N-tetrakis(2-ethylhexyl)isophthalamide, N,N,N,N-tetrakiscyclohexylisophthalamide
and o-hexadecyloxybenzamide), high-boiling organic solvents described in, for example,
JP-A's-2000-29159, 2001-281821, 2002-40606 and 8-110624, alcohols (e.g., isostearyl
alcohol and oleyl alcohol), aliphatic esters (e.g., dibutoxyethyl succinate, di-2-ethylhexyl
succinate, 2-hexyldecyl tetradecanoate, tributyl citrate, diethyl azelate, isostearyl
lactate and trioctyl citrate), aniline derivatives (e.g., N,N-dibutyl-2-butoxy-5-tert-octylaniline),
chlorinated paraffins (paraffins of 10 to 80% chlorine content), trimesic acid
esters (e.g., tributyl trimesate), dodecylbenzene, diisopropylnaphthalene, phenols
(e.g., 2,4-di-tert-amylphenol, 4-dodecyloxyphenol, 4-dodecyloxycarbonylphenol and
4-(4-dodecyloxyphenylsulfonyl)phenol), carboxylic acids (e.g., 2-(2,4-di-tert-amylphenoxy)butyric
acid and 2-ethoxyoctanedecanoic acid) and alkylphosphoric acids (e.g., di(2-ethylhexyl)phosphoric
acid and diphenylphosphoric acid).
Besides these high-boiling solvents, it is also preferred to use compounds
described in JP-A-6-258803 as high-boiling solvents.
Further, with respect to a latex dispersing method as one of polymer dispersing
methods, the process, effects and examples of immersion latexes are described in,
for example, United States Patent No. (hereinafter referred to as U.S. Pat. No.
4,199,363, DE (OLS) U.S. Pat. Nos. 2,541,274 and 2,541,230, Japanese Patent KOKOKU
Publication No. (hereinafter referred to as JP-B-) 53-41091 and European Patent
Publication No. (hereinafter referred to as EP) 029104 A. Moreover, a dispersion
by organic solvent soluble polymers is described in the pamphlet of PCT Publication
WO 88/00723.
Still further, as an auxiliary solvent, an organic solvent having a boiling
point of 30 to about 160° C. (e.g., ethyl acetate, butyl acetate, ethyl propionate,
methyl ethyl ketone, cyclohexanone, 2-ethoxyethyl acetate, dimethylformamide, methanol
or ethanol) may be used in combination therewith.
The tabular silver halide grains for use in the present invention will be described.
The silver halide photosensitive material of the present invention is characterized
by including at least one silver halide emulsion containing tabular grains having
an average equivalent sphere diameter of 0.55 μm or less and having an average
aspect ratio of 2 or greater, and/or at least one emulsion containing tabular silver
halide grains having an average aspect ratio of 8 or greater.
In the emulsion containing tabular silver halide grains having an average aspect
ratio of 8 or greater, the equivalent sphere diameter of grains thereof, although
not particularly limited, is preferably in the range of 0.1 to 3.0 μm, more
preferably 0.15 to 2.0 μm. The aspect ratio thereof is preferably 10 or greater,
more preferably 15 or greater. The aspect ratio is preferably in the range of 10
to 200, more preferably 15 to 200.
In the emulsion containing tabular silver halide grains having an average equivalent
sphere diameter of 0.55 μm or less and having an average aspect ratio of
2 or greater, it is preferred that grains having an average equivalent sphere diameter
of 0.55 μm or less and having an average aspect ratio of 3 or greater (especially
4 or greater) be contained. It is more preferred that grains having an average
equivalent sphere diameter of 0.5 μm or less and having an average aspect
ratio of 3 or greater (especially 4 or greater) be contained therein. The average
equivalent sphere diameter is preferably 0.20 μm or greater.
The tabular silver halide grains of the present invention, although may comprise
any type of silver halides, are preferably constituted of silver iodobromide or
silver iodochlorobromide. More preferably, the tabular silver halide grains are
constituted of silver iodobromide or silver iodochlorobromide wherein silver iodide
is contained in a ratio of 0.5 to 20 mol %.
It is preferred that the variation coefficient of intergranular silver iodide
content distribution be 20% or less. The variation coefficient is more preferably
15% or less, most preferably 10% or less. When the variation coefficient is greater
than 20%, unfavorably, hard gradation cannot be attained and sensitivity drop upon
pressure application is large. The silver iodide content of each individual grain
can be measured by analyzing the composition of each individual grain by means
of an X-ray microanalyzer. The terminology "variation coefficient of intergranular
silver iodide content distribution" means a value defined by the formula:
variation coefficient=(standard deviation/av. silver iodide content)×100
wherein the standard deviation of silver iodide content and the average silver
iodide content are obtained by measuring the silver iodide contents of at least
100, preferably at least 200, and most preferably at least 300 emulsion grains.
The measuring of the silver iodide content of each individual grain is described
in, for example, EP 147,868. There are cases in which a correlation exists between
the silver iodide content Yi (mol %) of each individual grain and the equivalent
sphere diameter Xi (μm) of each individual grain and cases in which no such
correlation exists. It is preferred that no correlation exist therebetween.
The silver halide emulsion of the present invention may have a multiple structure
with respect to the intragranular halogen composition. For example, it may have
a quintuple structure. Herein, the structure refers to having a structure with
respect to the distribution of silver iodide and means that the silver iodide contents
differ between individual structures in an amount of 1 mol % or more. The structures
with respect to the distribution of silver iodide can fundamentally be determined
by calculation from recipe values for the step of grain preparation. The change
of silver iodide content at each interface of individual structures can be sharp
or gentle. In the ascertainment thereof, although an analytical measuring precision
must be considered, the EPMA (Electron Probe Micro Analyzer) method is generally
effective. In this method, a sample wherein emulsion grains are dispersed so as
to avoid contacting thereof with each other is prepared. The sample is irradiated
with electron beams to thereby emit X-rays. Analysis of the X-rays enables performing
an elemental analysis of an extremely minute region irradiated with electron beams.
The measuring is preferably performed while cooling the sample in order to prevent
the damaging of the sample by electron beams. This method enables analyzing the
intragranular silver iodide distribution exhibited upon viewing the tabular grains
in the direction perpendicular to the main surface thereof. Further, by using a
specimen obtained by hardening the above sample and slicing the hardened sample
with the use of a microtome into extremely thin sections, the method also enables
analyzing the intragranular silver iodide distribution across the tabular grain section.
The tabular silver halide grains collectively refer to silver halide grains having
one twin plane, or two or more mutually parallel twin planes. The twin plane refers
to a (111) face on both sides of which the ions of all the lattice points are in
the relationship of reflected images. The tabular grains are each formed by two
mutually parallel main surfaces and sides joining these main surfaces to each other.
When the tabular grains are viewed from above with respect to the main surfaces,
the main surfaces have a triangular or hexagonal shape, or a circular shape corresponding
to rounded form thereof. The triangular, hexagonal and circular tabular grains
have triangular, hexagonal and circular mutually parallel main surfaces, respectively.
The aspect ratio of tabular grains refers to the quotient of grain diameter divided
by grain thickness. The grain thickness can be easily determined by performing
a vapor deposition of metal on grains, together with reference latex, in an oblique
direction thereof, measuring the length of grain shadow on an electron micrograph
and calculating with reference to the length of latex shadow. The grain diameter
refers to the diameter of a circle having an area equal to the projected area of
mutually parallel main surfaces of grain. The projected area of grains can be obtained
by measuring the grain area on an electron micrograph and effecting a magnification
correction thereto.
Supplemental addition of gelatin may be effected during the grain formation
in order to obtain monodisperse tabular grains of high aspect ratio. The supplemental
gelatin is preferably a chemically modified gelatin as described in JP-A's-10-148897
and 11-143002, or a gelatin of low methionine content as described in U.S. Pat.
Nos. 4,713,320 and 4,942,120. In particular, the former chemically modified gelatin
is a gelatin characterized in that at least two carboxyl groups have newly been
introduced at a chemical modification of amino groups contained in the gelatin.
Gelatin succinate or gelatin trimellitate is preferably used. The chemically modified
gelatin is preferably added prior to the growth step, more preferably immediately
after the nucleation. The suitable addition amount thereof is 50% or more, preferably
70% or more, based on the total weight of dispersion medium provided during grain formation.
Examples of silver halide solvents which can be used in the present invention
include organic thioethers (a) described in U.S. Pat. Nos. 3,271,157, 3,531,286
and 3,574,628 and JP-A's-54-1019 and 54-158917; thiourea derivatives (b) described
in JP-A's-53-82408, 55-77737 and 55-2982; silver halide solvents having a thiocarbonyl
group interposed between an oxygen or sulfur atom and a nitrogen atom (c) described
in JP-A-53-144319; and, as described in JP-A-54-100717, imidazoles (d), sulfites
(e), ammonia (f) and thiocyanates (g). Especially preferred silver halide solvents
are thiocyanates, ammonia and tetramethylthiourea. Although the amount of added
silver halide solvent depends on the type thereof, in the case of, for example,
a thiocyanate, the preferred addition amount is in the range of 1×10
-4
to 1×10
-2 mol per mol of silver halides.
As one preferable embodiment for tabular grains of the present invention, tabular
grains each having a dislocation line can be mentioned.
Firstly, tabular grains having a dislocation line will be described.
The dislocation line of the tabular grain can be observed by a direct method
using a transmission electron microscope at a low temperature described, for example,
in above mentioned J. F. Hamilton, Phot. Sci. Eng., 11, 57 (1967) or Shiozawa,
J. Soc. Phot. Sci. Japan. 35, 213 (1972). That is, silver halide grains are taken
out of an emulsion with taking care not to give a strong pressure which may induce
dislocation to the grains, placed on the mesh for electron microscope observation
and observed by a transmission method while cooling the sample in order to avoid
damage by electron beams (print our or the like). In this case, since thicker thickness
of the grain makes the electron beam more difficult to transmit, use of a high
voltage type (acceleration voltage of 200 kV or higher for grains with thickness
of 0.25 μm) electron microscope can make a more clear observation possible.
Using the photograph of the grain obtained by the method, position of the dislocation
line seen from the perpendicular direction to the main plain can be obtained.
As for position of the dislocation line of the tabular grain used in the invention,
it starts from the distance of x % of the length between the center and the edge
to the edge, in relation to the long axis direction. The value of x is preferably
10≦x<100, more preferably 30≦x<98, and further more preferably
50≦x<95. On this occasion, figure that is formed by binding the position
where the dislocation lines start is nearly analogous to the figure of the grain,
however sometimes it twists to become not completely analogous. Direction of the
dislocation line is approximately the direction from the center to the edge. But
it often meanders.
As for number of the dislocation lines of the tabular grains used in the invention,
presence of grains having 10 dislocation lines or more by 50% (number of pieces)
or more is preferable. More preferably the tabular grains including grains having
10 dislocation lines or more by 80% (number of pieces) or more, and particularly
preferably those including grains having 20 dislocation lines or more by 80% (number
of pieces) or more, are recommended.
When the silver halide grains of the present invention are tabular grains having
dislocation lines, the aspect ratio thereof is preferably 2 or more, more preferably
3 or more, and most preferably 4 to 20.
Dislocation of the tabular grain used in the invention is introduced
by providing a high-iodide phase inside the grain. The high-iodine phase means
a silver halide solid solution containing iodine. As silver halide in this case,
silver iodide, silver iodobromide or silver chloroiodobromide is preferable, silver
iodide or silver iodobromide is more preferable, and silver iodide is particularly preferable.
Amount of silver halide forming the high-iodide phase is, in terms of silver,
30 mol % or less, and more preferably 10 mol % or less of the total amount of silver
in the grains.
A layer to be grown outside the high-iodide phase need contain a less content
of
iodide than that in the high-iodide phase. Preferably the iodide content is 0 to
12 mol %, more preferably 0 to 6 mol %, and most preferably 0 to 3 mol %.
As the preferable method for forming the high-iodide phase, there is a method
in which it is formed by adding an emulsion containing fine grains of silver iodobromide
or silver iodide. As these fine grains, those that have been previously prepared
can be used and, more preferably, those that have been just prepared can be also used.
Firstly, the case, in which previously prepared fine grains are used, will
be described. In this case, there is a method such that previously prepared fine
grains are added and ripped to be dissolved. As a more preferable method, there
is a method such that the silver iodide fine grain emulsion is added and then a
silver nitrate aqueous solution, or a silver nitrate aqueous solution and halide
aqueous solution are added. In this case, dissolution of the silver iodide fine
grains is accelerated by the addition of the silver nitrate aqueous solution. Rapid
addition of the silver iodide fine grain emulsion is preferable.
"Rapid addition of the silver iodide fine grain emulsion" means to complete
preferably the addition of the silver iodide fine grain emulsion within 10 minutes.
More preferably, it means to complete the addition within 7 minutes. Although this
condition may vary depending on the adding system, such as temperature, pBr, pH,
kind and concentration of protective colloid such as gelatin, and presence or absence
and kind and concentration of a silver halide solvent, a shorter period of time
is preferable, as described above. When adding, it is preferable not to add substantially
an aqueous solution of silver salt such as silver nitrate. Temperature of the system
at addition ranges preferably from 40 to 90° C., and particularly preferably
from 50 to 80° C.
The silver iodide fine grain emulsion is not limited as long as it is substantially
comprised of silver iodide. The silver iodide fine grain emulsion may contain silver
bromide and/or silver chloride as long as these can form mixed crystals. Details
will be described later.
Other preferred forms of the tabular grains of the present invention are tabular
silver halide host grains of 2 or higher aspect ratio each having two main planes
parallel to each other (hereinafter referred to as "host tabular grains" or "host
grains") and silver halide grains composed of such host grains each having its
surface provided with protrusions of silver halides (hereinafter referred to as
"silver halide protrusions" or "protrusions") through epitaxial junction (hereinafter
referred to as "epitaxial junction tabular grains"). Herein, the protrusions refer
to portions which upheave on the host grains, and can be identified by observation
through an electron microscope.
The host tabular grains of the present invention are each formed of two main
planes parallel to each other and sides joining the main planes with each other.
Although the configuration of main planes may be any of an arbitrary polygon enclosed
by lines, a circle, ellipse or the like or shape enclosed by indeterminate curve
and a shape enclosed by a combination of line and curve, it is preferred that the
configuration have at least one apex. More preferred configuration of the main
planes is a triangle with three apexes, or a quadrangle with four apexes, or a
pentagon with five apexes, or a hexagon with six apexes, or a combination thereof.
Herein, the apex refers to a non-rounded corner created by two adjacent sides.
When the corner is rounded, the apex refers to a point bisecting the length of
rounded curve portion.
The main planes of host tabular grains for use in the present invention may have
any type of crystal structure. Specifically, although the crystal structure of
main planes may be any of (111) faces, (100) faces, (110) faces and higher-order
faces, it is most preferred that the main planes of tabular grains consist of (111)
faces or (100) faces. With respect to tabular grains whose main planes consist
of (111) faces, in preferred mode, grains whose main planes have a configuration
of hexagon with six apexes occupy 70% or more of the total projected area of grains.
With respect to tabular grains whose main planes consist of (100) faces, in preferred
mode, grains whose main planes have a configuration of quadrangle with four apexes
occupy 70% or more of the total projected area of grains.
The host tabular grains for use in the present invention preferably exhibit an
aspect ratio of 2 or higher, the aspect ratio referring to the quotient of grain
equivalent circle diameter divided by grain thickness. This aspect ratio is more
preferably in the range of 5 to 200, still more preferably 10 to 200, and most
preferably 15 to 200. Herein, the equivalent circle diameter of grains refers to
the diameter of a circle with an area equal to the projected area of main plane thereof.
The equivalent circle diameter of host tabular grains can be determined by, for
example, taking a transmission electron micrograph according to the replica method,
measuring the projected area of each individual grain through correction as to
photographing magnification and calculating a diameter in terms of equivalent circle
diameter from the projected area measurement. Although the grain thickness may
not be simply calculated from the length of the shadow of the replica because of
epitaxial deposition, the calculation can be made by measuring the length of the
shadow of the replica with respect to grains before the epitaxial deposition. Alternatively,
even after the epitaxial deposition, the grain thickness can be easily determined
by slicing a sample after emulsion coating so as to obtain a section and taking
an electron micrograph of the section.
The equivalent circle diameter of host tabular grains for use in the present
invention is preferably in the range of 0.5 to 10.0 μm, more preferably 0.7
to 10.0 μm. The grain thickness thereof is preferably in the range of 0.02
to 0.5 μm, more preferably 0.02 to 0.2 μm, and most preferably 0.03
to 0.15 μm.
With respect to the host tabular grains for use in the present invention, the
intergranular variation coefficient of equivalent circle diameter is preferably
40% or less, more preferably 30% or less, and most preferably 25% or less. The
terminology "inter-granular variation coefficient of equivalent circle diameter"
used herein means the value obtained by dividing a standard deviation of equivalent
circle diameter distribution of grains by an average equivalent circle diameter
and by multiplying the quotient by 100.
With respect to the epitaxial junction tabular grains, silver halide protrusions
may be formed through epitaxial junction at any arbitrary position of the surfaces
of host tabular grains. The formation position is preferably on the main surfaces,
or apex portions or sides excluding apex portions of host tabular grains. The most
preferred formation position is on the apex portions. Herein, the apex portions
refer to sections enclosed by a circle of radius which is equal to ⅓ of
the length of shorter side among two sides adjacent to each apex of tabular grains,
as viewed perpendicularly to the main planes of tabular grains. In particular,
silver halide grains having protrusions provided on all the apex portions of main
planes of host tabular grains occupy 70% or more in preferred mode, 80% or more
in more preferred mode and 90% or more in still more preferred mode based on the
total projected area.
The amount of silver contained in the silver halide protrusions of epitaxial
junction tabular grains is characterized by being 12% or less based on the amount
of silver contained in host tabular grains. This ratio of silver amount is more
preferably in the range of 0.5 to 10%, still more preferably 1 to 8%. When the
silver amount ratio is too low, the reproducibility of epitaxial formation when
repeated would be poor. On the other hand, when the ratio is too high, problems
such as sensitivity lowering and graininess deterioration would occur. The proportion
of the surface of silver halide protrusions to the entire grain surface is preferably
50% or less, more preferably 20% or less based on the surface of host tabular grains.
It is preferred that the silver halide protrusions of epitaxial junction tabular
grains contain pseudohalide compounds. The terminology "pseudohalide compounds"
means a group of compounds known as having properties similar to those of halide
compounds (specifically, those which can provide satisfactorily electrically negative
monovalent anion groups exhibiting at least the same positive Hammett sigma values
as exhibited by halide compounds, for example, CN
-, OCN
-,
SCN
-, SeCN
-, TeCN
-, N
3-,
C(CN)
3- and CH
-), as described in JP-A-7-72569.
The content of pseudohalide compounds in the protrusions is preferably in the range
of 0.01 to 10 mol %, more preferably 0.1 to 7 mol %, based on the silver quantity
of the protrusions.
In the epitaxial junction tabular grains, with respect to not only the host grains
but also the protrusions, the halogen composition thereof consists of pure silver
bromide, or consists of, containing silver bromide at a ratio of 70 mol % or more,
silver iodobromide, silver chlorobromide or silver chloroiodobromide. When the
silver bromide content is less than 70 mol %, an adverse effect of intensification
of fog increase after storage would occur. The silver bromide content is more preferably
80 mol % or more, most preferably 90 mol % or more.
In the epitaxial junction tabular grains, the average silver iodide content based
on all the grains without exception is preferably 20 mol % or less, more preferably
15 mol % or less and most preferably 10 mol % or less. When the silver iodide content
exceeds 20 mol %, it would be infeasible to obtain satisfactorily high sensitivity.
An embodiment wherein the average silver iodide content of protrusions is lower
than the average silver iodide content of host grain outer shell 8% (based on the
silver quantity of host grains) is preferred. Herein, the host grain outer shell
8% refers to a layered region of host grains arranged from the surface toward the
grain center wherein the amount of silver contained is 8% of the total silver quantity
of host grains.
In the epitaxial junction tabular grains, with respect to not only the host grains
but also the protrusions, the silver chloride content thereof is preferably 8 mol
% or less, more preferably 4 mol % or less and most preferably 1 mol % or less.
In the epitaxial junction tabular grains, it is preferred that the intergranular
distribution of silver iodide content be monodisperse. In particular, in preferred
embodiment, silver halide grains whose silver iodide content is in the range of
0.6 I to 1.4 I providing that the average silver iodide content based on all the
grains is I mol % occupy 70% or more of the total projected area thereof. In further
preferred embodiment, silver halide grains whose silver iodide content is in the
range of 0.7 I to 1.3 I occupy 70% or more of the total projected area thereof.
In the epitaxial junction tabular grains, the host grains, or protrusions, or
both host grains and protrusions may contain, as portion of silver halides, silver
salts other than silver chloride, silver bromide and silver iodide, for example,
silver rhodanide, silver selenocyanide, silver tellulocyanide, silver sulfide,
silver selenide, silver telluride, silver carbonate, silver phosphate, silver organic
acid salts, etc. Alternatively, silver salts other than silver halides may be contained
in the emulsion of the present invention as separate grains.
The host grains for use in the present invention may have a double structure
or further multiple structure with respect to the intragranular halogen composition
distribution. For example, the host grains may have a quintuple structure. Herein,
the terminology "structure" refers to structuring on the intragranular distribution
of silver iodide, and means that between structures, there is a silver iodide content
difference of 1 mol % or more. This structure on the intragranular distribution
of silver iodide can fundamentally be determined by calculation from recipe values
provided in the grain preparation process. The change of silver iodide content
at an interface of structures may be sharp or gentle. For identification thereof,
although the measurement accuracy in analysis must be taken into consideration,
the EPMA method (Electron Probe Micro Analyzer method) is generally effective.
In this method, a sample wherein emulsion grains are well dispersed so as to avoid
contacting thereof to each other is prepared. The sample is irradiated with electron
beams so as to emit X-rays. An elemental analysis of extremely minute region having
been irradiated with electron beams can be performed by an analysis of the X-rays.
This measurement is preferably carried out while cooling to low temperature in
order to prevent sample damaging by electron beams. This technique enables analysis
of the intragranular silver iodide distribution of tabular grains when viewed perpendicularly
to the main planes thereof. Further, by the use of a sample obtained by solidifying
the
