Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Silver compound sensitizer containing
Reexamination Certificate
2003-03-25
2004-08-24
Le, Hoa Van (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Silver compound sensitizer containing
C430S605000
Reexamination Certificate
active
06780579
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a silver halide emulsion, more particularly, to a silver halide emulsion which causes less fog, which is highly sensitive and contrasty, which shows excellent reciprocity law properties at high-intensity exposure, which undergoes less change in sensitivity under different humidity conditions upon exposure, and which shows excellent humid abrasion resistance, and to a silver halide color photographic light-sensitive material using the same and an image-forming method using the light-sensitive material.
BACKGROUND OF THE INVENTION
In recent years, there has been an increased demand for performance of color photographic paper, such as high sensitivity, high image quality and toughness during processing. Thus, there has been a demand for an emulsion which causes less fog and which is highly sensitive and contrasty, an emulsion which suffers less change in sensitivity during storage, an emulsion which suffers less change in photographic properties under different temperature and humidity conditions upon exposure or an emulsion which shows excellent humid abrasion resistance. On the other hand, with the spread of laser scan-exposing apparatuses, adaptability for short-time and high-intensity exposure has become one of important performances of color photographic papers. The laser scanning exposure's great characteristics are its high-speed exposure and improved resolution. In applying this to color photographic papers, however, adaptability for an extremely short-time (specifically 10
−6
second) and high-intensity exposure not having so far been required is anew required.
For such requirement, the chemically sensitizing method has been considered to play an important role, and various noble metal-sensitizing methods and chalcogen-sensitizing methods have been proposed. However, many of them use a noble metal sensitizer and a chalcogen sensitizer in combination. Improvement of the noble metal sensitizers have been continued until quite recently as shown below with respect to gold sensitizers.
(Regarding Gold Sensitizers)
The gold sensitizing method is a means effective for attaining high sensitivity and adaptability for high-intensity exposure. It has been known from old to use Au(III) compounds such as chloroauric acid. Chloroauric acid is fully stable in an aqueous solution but, on the other hand, it is insufficient with such photographic properties as sensitivity, gradation, adaptability for high-intensity exposure, change in sensitivity during storage, humid abrasion resistance and toughness against temperature and humidity environment upon exposure, thus having been required to improve.
As gold compounds to be used for gold sensitization, there have been known gold (I) compounds containing meso-ionic ligand (hereinafter referred to as “meso-ionic gold (I) compounds”), and JP-A-4-267249 [patent document 1] discloses that such compounds are useful for producing highly sensitive, contrasty emulsions. (The term “JP-A” as used herein means an “unexamined published Japanese patent application”.) JP-A-11-218870 [patent document 2] proposes a method of utilizing a gold (I) complex of a mercapto compound.
However, they are insufficient with such photographic properties as sensitivity, adaptability for high-intensity exposure, change in sensitivity during storage, humid abrasion resistance and toughness against temperature and humidity environment upon exposure, thus having been required to improve.
(Regarding Chalcogen Sensitizers)
As to chalcogen sensitizers, too, development of selenium sensitizers (for example, JP-A-5-40324 [patent document 3], JP-A-4-25832 [patent document 4], JP-A-271341 [patent document 5], JP-A-4-109240 [patent document 6], JP-A-5-224332 [patent document 7], JP-A-6-43576 [patent document 8], and JP-A-6-175258 [patent document 9]), tellurium sensitizers (for example, JP-A-4-333043 [patent document 10], JP-A-5-303157 [patent document 11], and JP-A-4-204640 [patent document 12]) has been continued as well as sulfur sensitization.
(Regarding Combined Use of Gold Sensitization and Chalcogen Sensitization (=Gold-chalcogen Sensitization)
This technique is an improvement of the gold sensitizer and the chalcogen sensitizer, and it has been intended to attain gold-chalcogen sensitization (for example, gold-sulfur sensitization and gold-selenium sensitization) by combining the two.
That is, gold sensitization is effected by the release of gold atom from a gold sensitizer, and chalcogen sensitization is effected by the release of chalcogen atom from a chalcogen sensitizer, and gold-chalcogen sensitization is attained by the two.
Various examples are known as chemically sensitizing methods using a compound containing a chalcogen atom and a metal atom, and there have been proposed, as gold sensitizers, gold complexes and gold salts with which sulfur atom coordinate (for example, JP-A-8-69075).
However, many of the compounds used in these proposals fail to effect gold-sulfur sensitization through a single compound because they do not substantially release sulfur atom, though they function as a gold sensitizer. One example thereof is the aforesaid gold (I) compound containing meso-ionic ligand (hereinafter referred to as “meso-ionic gold (I) compound”) and is disclosed in JP-A-4-267249 [patent document 13]. Another example thereof is a gold (I) complex of a mercapto compound described in JP-A-11-218870 [patent document 14].
As an example of a single compound capable of effecting gold-sulfur sensitization, Na
3
Au(S
2
O
3
)
2
(Hypo gold) has long been known. However, since thiosulfate ion therefrom functions as a sulfur sensitizer, it is disadvantageous for conducting chemical sensitization wherein gold/sulfur ratio is more than 1/2, e.g., 1/1, though it is advantageous for conducting chemical sensitization wherein the gold/sulfur ratio is 1/2.
As an example similar to Na
3
Au(S
2
O
3
)
2
, JP-A-2001-75215 [patent document 16] discloses an Au (I) complex having two molecules of thiourea compound. However, since the two molecules of the thiourea compound can function as a sulfur sensitizer, it involves the same disadvantage as Na
3
Au(S
2
O
3
)
2
. On the other hand, in consideration of these circumstances, JP-A-2001-75216 [patent document 17] discloses an Au (I) complex not having two molecules but having one molecule of the thiourea compound as a ligand. Here, examples having one reactive labile sulfur group and one Au(I) atom are described, which do not involve the above-described problem with Na
3
Au(S
2
O
3
)
2
and the compounds described in JP-A-2001-75215 [patent document 16]. However, their photographic properties are insufficient with respect to adaptability for high-intensity exposure, toughness against temperature humidity environment upon exposure, and latent image stability, and hence they have been desired to improve.
As a further example of a compound which can effect gold-sulfur sensitization as a single compound, JP-B-45-29274 [patent document 18] describes a gold-sensitizing method using an aurous mercaptoglucose ((1-thioglucopyranosato) gold). (The term “JP-B” as used herein means an “examined Japanese patent publication”.) The compound has the Au-to-sulfur atom ratio of 1:1. However, this is not a proposal of conducting chemical sensitization by releasing chalcogen-gold pair, and is insufficient with respect to sensitivity, change in sensitivity under different environmental conditions upon exposure, latent image stability, and reciprocity law properties at a high intensity exposure, thus having been desired to improve.
Also, nothing has been described therein with respect to an emulsion of silver halide grains containing silver iodide in their shell portions.
(Regarding Emulsion of Silver Halide Grains Containing Silver Iodide in Their Shell Portions)
U.S. Pat. Nos. 5,726,005 and 5,736,310 disclose that an e
Matsunaga Atsushi
Mifune Hiroyuki
Mizuno Masafumi
Sasaki Hirotomo
Suzuki Hiroyuki
Fuji Photo Film Co. , Ltd.
Le Hoa Van
Sughrue & Mion, PLLC
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