Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Silver compound sensitizer containing
Reexamination Certificate
2000-02-25
2002-11-12
Baxter, Janet (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Silver compound sensitizer containing
C430S569000, C430S597000
Reexamination Certificate
active
06479230
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a light-sensitive silver halide photographic emulsion and, more particularly, to a tabular silver halide grain photographic emulsion having an aspect ratio of 2 or more. The present invention also relates to a silver halide photographic light-sensitive material using the emulsion.
Methods of manufacturing and techniques of using tabular grains are disclosed in U.S. Pat. Nos. 4,434,226, 4,439,520, 4,414,310, 4,433,048, 4,414,306, and 4,459,353. Known advantages of tabular grains are improvements of sensitivity including improvements of color sensitization efficiency by sensitizing dyes, and improvements of the sensitivity/graininess relationship.
Dislocations of silver halide grains are described in references such as C. R. Berry, J. Appl. Phys., 27, 636 (1956), C. R. Berry, D. C. Skillman, J. Appl. Phys., 35, 2165 (1964), J. F. Hamilton, Phot. Sci. Eng., 11, 57 (1967), T. Shiozawa, J. Soc. Phot. Sci. Japan, 34, 16, (1971), and T. Shiozawa, J. Soc. Phot. Sci. Japan, 35, 213, (1972). These references describe that dislocations in crystals can be observed by an X-ray diffraction method or low-temperature transmission electron microscopy and diverse dislocations are produced in crystals by intentionally giving distortion to the crystals.
Attempts to improve various photographic properties by intentionally introducing under control these dislocations to tabular silver halide grains are known. Jpn. Pat. Appln. KOKAI Publication No. (hereinafter referred to as JP-A-)63-220238 has disclosed a method of introducing dislocation lines onto the peripheral region of a tabular grain. JP-A-1-102547 has disclosed a method of introducing dislocation lines onto the major faces of a tabular grain. JP-A-3-237450 has disclosed tabular grains having dislocation lines, which are chemically sensitized with a selenium sensitizer, a gold sensitizer, and a sulfur sensitizer and have an aspect ratio of 3 or more. JP-A-6-27564 has disclosed tabular grains having dislocation lines only in fringes.
On the other hand, JP-A-61-43740 has disclosed an emulsion spectrally sensitized to have high red sensitivity by the combination of bispyridinium salt and a cyanine dye. JP-A-61-43740 describes that an advantageous addition amount of this bispyridinium salt is, as a weight ratio, 0.25 to 100 times the addition amount of a cyanine dye. In practice, bispyridinium salt is added in amount equimolar with a cyanine dye or more. When large amounts of sensitizing dyes are allowed to effectively function, the color sensitization efficiency by these sensitizing dyes improve. However, examinations by the present inventors have found that in a system to which large amounts of sensitizing dyes are added, the sensitivity increasing effect is little even if bispyridinium salt having adsorptivity to an emulsion is added in amount equimolar with a cyanine dye or more. Accordingly, the development of a technique which achieves a remarkable sensitivity increasing effect with small addition amounts is being desired.
JP-A-6-242534 has disclosed a silver halide sensitized material containing a bis heterocyclic onium salt compound. JP-A-6-242534 describes that the photographic properties of an emulsion containing 60% or more of silver chloride are improved in a high-contrast negative sensitized material for photographic process which also contains a hydrazine derivative. JP-A-10-83040 describes that the sensitivity and storage stability of a direct positive photographic light-sensitive material using both an onium salt compound and previously fogged emulsions are improved.
As described above, the combination of onium salt such as bispyridinium salts and photographic emulsions is known. However, the effect of using this combination together with tabular grains to which dislocation lines are introduced is unknown.
The present inventors made extensive studies and have found a means capable of significantly improving photographic sensitivity by using specific onium salt in particularly tabular grains to which dislocation lines are introduced.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to provide a high-sensitivity silver halide emulsion having a high sensitivity/fog ratio.
It is another object of the present invention to provide a silver halide photographic light-sensitive material containing such an emulsion.
DETAILED DESCRIPTION OF THE INVENTION
The object of the present invention can be achieved by the following silver halide emulsions and the silver halide photographic light-sensitive materials.
(I) A silver halide photographic light-sensitive emulsion containing, at a ratio of 50% or more of the total projected area of silver halide grains, tabular silver halide grains each having (111) faces as parallel major faces and an aspect ratio of 2 or more and including 10 or more dislocation lines per grain, and containing at least one compound represented by formula (1) or (2) below:
wherein A represents an atomic group required to form a nitrogen-containing hetero ring, and each of B and E represents one or a combination of alkylene, arylene, —O—, —S—, —SO
2
—, —CO
2
— and —N(R5)—. R5 represents a hydrogen atom, an alkyl group, or an aryl group. Each of —O—, —S—, —SO
2
—, —CO
2
— and —N(R5)— is adjacent to and connects with alkylene or arylene provided that each of —O—, —S—, —SO
2
—, —CO
2
—, and —N(R5)— is adjacent to and connects with alkylene or arylene at both ends thereof. B does not bond to the nitrogen atom which forms a hereto ring together with A and which bonds to the carbon atom by a double bond. Each of R1 and R2 represents an alkyl group or an aralkyl group, a n d each of R3 and R4 represents a substituent. Although X represents an anion group, no X exists in the case of intramolecular salt.
(II) The emulsion described in item (I) above, wherein the silver halide grains are made red-sensitive by a sensitizing dye, and the addition amount of a compound represented by formula (1) or (2) is 25 mol % of the addition amount of the sensitizing dye or less.
(III) The emulsion described in item (I) or (II) above, wherein the surface silver iodide content of the silver halide grains is 5 mol % or less.
(IV) The emulsion described in one of items (I) to (III) above, wherein the silver halide grains are subjected to reduction sensitization.
(V) The emulsion described in one of items (I) to (IV) above, wherein the compound represented by formula (2) is represented by formula (3) below:
wherein D represents one or an alternate combination of alkylene and —O—. Each of m and n represents 0, 1, or 2. Each of R6 and R7 represents a 4- to 20-carbon alkyl group, a 6- to 20-carbon aryl group, or a 7- to 20-carbon aralkyl group. If m=2 and n=2, R6 or R7 can form a condensed ring as a benzene ring. Although X represents an anion group, no X is necessary in the case of intramolecular salt.
(VI) A silver halide photographic light-sensitive material having at least one silver halide light-sensitive emulsion layer on a support, wherein the silver halide light-sensitive emulsion layer contains the light-sensitive emulsion described in one of items (I) to (V) above.
The present invention will be described in detail below.
Details of formulas (1), (2), and (3) will be described below. In these formulas, A represents an atomic group required to form a nitrogen-containing hetero ring and can contain a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, or a sulfur atom. Additionally, a benzene ring can further condensed to the ring formed with A. Preferable examples are a pyridine ring, a quinoline ring, and an isoquinoline ring. A can also be substituted. Preferable examples of this substituent are a halogen atom, a substituted or nonsubstituted alkyl group (e.g., methyl and hydroxyethyl), a substituted or nonsubstituted aryl group (e.g., phenyl and p-chlorophenyl), a substituted or nonsubstituted aralkyl group (e.g., benzyl), an acyl group, a hydroxy group, a nitro group, an acylamino group, an alkoxy group, and a carbamoyl group.
Each of
Baxter Janet
Fuji Photo Film Co. , Ltd.
Walke Amanda C.
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