JPH07230139A - Silver-halide photograph element containing infrared sensitization coloring matter - Google Patents

Abstract

PURPOSE: To provide a solution of an infrared sensitizing dyestuff having preservable stability and prevented from losing sensitizing effect in several hours after preparation. CONSTITUTION: The stabilizing method of the solution of the infrared sensitizing dyestuff includes adding the stabilizing quantity of (a) an organic reducing agent selected from a group composed of ascorbic acid, ascorbic acid isomer, glucose, cyclodextrine and the mixture thereof and (b) an organic or inorganic buffer.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to a method of stabilizing a solution of an infrared sensitizing dye and a silver halide photographic element containing a layer containing said infrared sensitizing dye.

[0002]

It is known that silver halide photographic elements can be spectrally sensitized by infrared radiation.
About this, Mees and James
d James), The Theory of Photographic Processes, Third Edition, Macmillan, Inc., pages 198-199 (1966). Silver halide is intrinsically sensitive only to light in the blue region of the spectrum. Therefore, when the silver halide is exposed to radiation of other wavelengths, such as green light, red light, infrared light, etc., a spectral sensitizing dye is necessary to make the silver halide sensitive to the radiation. . As is known in the art, silver halides having a spectral sensitizing dye absorbed on the grains can be sensitive to radiation of other wavelengths in addition to the intrinsic blue sensitivity.

With the advent of lasers, and particularly solid state laser diodes emitting in the infrared region of the spectrum (eg, 750 to 1500 nm), interest in infrared sensitization has increased. Many different processing methods and articles useful for exposing laser diodes have been proposed. Among these are CAT (Computer Assisted Tomography) scanners, graphic arts products, and infrared-sensitized false color sensitizations such as those described in US Pat. No. 4,619,892. Contains photographic elements.

There is much literature on dye structures for infrared sensitizing dyes. Examples of patents disclosing the dye include US Pat. No. 4,011,083. The most common infrared sensitizing dye is the tricarbocyanine dye. "Tricarbocyanine" refers to the amidinium-ion chromophoric system in the art.
mophoric system) (Meas above and James
(See page 201) is a term used to include a dye. Further, tricarbocyanine infrared sensitizing dyes, U.S. Patent Nos. 4,536,473, 4,959,294, and 5,061,
618, 4,619,892, 3,506,655, 3,552,974
No. 3,623,881 and No. 3,758,461.

The infrared sensitizing dye may be dispersed directly in the emulsion, or, alternatively, it may be first dissolved in a suitable solvent and then added as a solution in the emulsion. A method of adding an infrared sensitizing dye to a photographic emulsion is described in U.S. Patent Nos. 3,469,987 and 3,676,1.
No. 47, No. 3,822,135, No. 4,199,360, No. 2,912,343
, 3,342,605, 2,996,287, and 3,429,83.
No. 5 is disclosed.

The problems with many known infrared sensitizing dyes are:
Poor storage stability, which limits its utility in making photographic elements. In fact, a solution of the infrared sensitizing dye must be added to the silver halide emulsion within hours of making it, otherwise the solution will decompose rapidly and lose the sensitizing effect.

US Pat. No. 5,147,756 describes a method for stabilizing aqueous solutions of aryl hydrazides. These solutions may be made by adding stabilizing amounts of ascorbic acid, tartaric acid, citric acid, glucose and the like. The aqueous solution thereby has a longer shelf life. Stabilized aryl hydrazides are useful in silver halide photographic emulsions and produce fairly high contrast images in graphic arts materials.

It is also known in the art that ascorbic acid is useful for solving a problem different from stabilization of a solution in which an infrared sensitizing dye is dissolved.

US Pat. No. 5,037,734 describes a silver halide photographic emulsion spectrally sensitized to the infrared range of the electromagnetic spectrum. The emulsion is
An organic reducing agent having an oxidation potential of about +0.10 to about +0.70 volt with respect to SCE (saturated mercury (I) chloride electrode) (eg, ascorbic acid or dihydroanhydropiperidinohexose reductone), and infrared Stabilized by a combination of nonionic surfactants that can dissociate the sensitizing dye aggregates. Problems such as low oxidation potential and propensity for oxidative degradation of the infrared dyes were reduced by this method and good photographic speed and degree of fog were achieved. This patent solves the problem of stabilization of emulsions spectrally sensitized in the infrared region, but after several hours, a treatment for stabilizing the solution containing the infrared sensitizing dye added to the emulsion at the coating stage. Is not suggested.

Ascorbic acid is also known in the art as a supersensitizer in photosensitive materials having high sensitivity and good color reproducibility. In fact, U.S. Pat. No. 4,917,997 describes a silver halide emulsion combining an ascorbic acid compound, a bisaminostilbene compound substituted with a pyrimidine derivative and one dye, the photographic emulsion being of increased spectral sensitivity. Shows sex. U.S. Patent No. 4,
No. 897,343 is one or more alkali metal sulfite compounds,
And spectrally sensitized silver halide photographic emulsions containing one or more ascorbic acid compounds as supersensitizers for spectral sensitizing dyes.

Ascorbic acid is also known in the art as a reducing sensitizer in the emulsion manufacturing process. European Patent Application No. 371,338 discloses monodisperse silver halide emulsions that have been reduction sensitized with ascorbic acid in the presence of thiosulfonic acid compounds during precipitation of silver halide grains or during the process of making silver halide emulsions. ing. The manufacturing process of silver halide emulsions can be broadly classified into, for example, grain formation, desalting, chemical sensitization and coating steps. Grain formation can be further divided into nucleation, ripening, and precipitation stages. European Patent Application No. 378,841 preferably describes a photographic material comprising an emulsion layer containing silver halide grains reduction sensitized with ascorbic acid before or simultaneously with sulfur sensitization, selenium sensitization or gold sensitization. is doing. European Patent Application No. 404,142 describes the steps of reduction sensitizing an emulsion with ascorbic acid, and in the process of producing a plate-like emulsion,
Describes a method of treating a tabular silver halide emulsion comprising the steps of sulfur sensitizing, selenium sensitizing, or gold sensitizing a tabular emulsion in the presence of a nitrogen-containing heterocyclic compound that forms a complex with silver. ing.

[0012]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a solution of an infrared sensitizing dye which has storage stability and does not lose its sensitizing effect within a few hours after preparation. And It is a further object of the present invention to provide a silver halide photographic material containing an infrared sensitizing dye which aids in obtaining images with improved sensitivity. This problem is particularly relevant in the medical imaging field where there is a need to obtain sensitive images to facilitate evaluation of the images by the end user.

[0013]

The present invention relates to a method for stabilizing a solution of an infrared sensitizing dye. In particular, it relates to methods of increasing the stability of solutions of infrared sensitizing dyes using stabilizing amounts of organic reducing agents and organic or inorganic buffers. The invention further provides a silver halide photographic element comprising a support, one or more infrared sensitized silver halide emulsion photographic layers and one or more hydrophilic colloid non-photosensitive layers.
The above-mentioned infrared sensitizing layer relates to a silver halide photographic element containing an infrared sensitizing dye, and a stabilizing amount of an organic reducing agent and an organic or inorganic buffering agent.

The method of the present invention provides a solution of an infrared sensitizing dye which maintains its stability during storage without losing its sensitizing effect. This allows the solution of the infrared sensitizing dye to be added to the photographic material for up to 2 days or more after preparation (which was conventionally a waste of several hours). The use of stabilizing solutions of infrared sensitizing dyes in silver halide photographic elements also improves photographic speed.

Generally, the infrared sensitizing dye used in the present invention is
It may be first dissolved in a suitable solution (eg methyl alcohol, ethyl alcohol, methyl cellosolve, acetone, water, pyridine or mixtures thereof) and then added as a solution in the silver halide emulsion. The solution is
It generally contains from 0.02% to 1.0% by weight of infrared sensitizing dye and must be added to the silver halide emulsion within 1-12 hours of its preparation. Otherwise, the solution decomposes rapidly, diminishing its sensitizing effect.

According to the invention, a stabilizing amount of an organic reducing agent,
And the use of organic or inorganic alkaline buffers stabilizes the solution of infrared sensitizing dyes. The solvent that dissolves the infrared sensitizing dye used in the present invention is a mixture of water and alcohol (methyl alcohol, ethyl alcohol, phenyl cellosolve, etc.), or only water. The organic reducing agent is selected from the group consisting of ascorbic acid, ascorbic acid isomers, glucose, cyclodextrin, and mixtures thereof, and organic and inorganic buffers include alkali metal (e.g. sodium, potassium,
Lithium, etc.) acetate, citrate, phosphate, borate, tartrate, etc. Preferably, the organic reducing agent is ascorbic acid or an ascorbic acid derivative (for example, ascorbic acid, L-ascorbic acid,
L-sodium ascorbate, D-sodium ascorbate, etc.). The amount of the organic reducing agent is in the range of 5 to 500 mg, preferably 10 to 300 mg, and most preferably 2 with respect to 100 ml of the solution containing 0.1% by weight of the sensitizing dye.
It is in the range of 0 to 200 mg. Preferably the alkaline buffer is sodium acetate. The amount of the alkaline buffer is in the range of 20 to 1000 mg, preferably in the range of 100 to 500 mg, based on 100 ml of the solution containing 0.1% by weight of the sensitizing dye.

The preferred method of this invention is to dissolve the infrared sensitizing dye in a phenyl cellosolve solvent and heat to 50 ° C. to obtain a solution, after which methyl alcohol and the desired amount of sodium acetate and ascorbic acid are added. Consists of. The resulting solution is 100m with methanol at 20 ° C.
to l. The solution obtained with the reducing agent and the buffer is transparent, and is stable for only a few hours when the reducing agent and the buffer are not included, whereas it is stable for a sufficient period of time, for example, 2 days or more. Keep Further, while the solution with the reducing agent and the buffer used in the present invention does not show solids, the solution containing no reducing agent and the buffer has, for example, 1 to 1
A solid forms in a short time of 2 hours.

The stabilizing solutions of the infrared sensitizing dyes described above may be kept in storage and later added to the silver halide emulsion immediately before coating on a suitable support and they are halogenated immediately after preparation. The sensitizing effect is not lost even when it is not added to the silver emulsion.

Infrared sensitizing dyes that can be used in the present invention include those represented by the following general formula (I):

[Chemical 5]

In the formula, Z ₁ and Z ₂ each independently represent an atom necessary for completing a substituted or unsubstituted 5- or 6-membered heterocyclic nucleus. R ₁ and R ₂ each independently represent a substituted or unsubstituted alkyl group. L ₁ ,
L ₂ , L ₃ , L ₄ and L ₅ each independently represent a substituted or unsubstituted methine group. X ⁻ represents an anion. n represents an integer of 1 to 2, and when the dye forms an intramolecular salt, n is 1. p and q are
Each independently represents 0 or 1, and z represents 2.

According to the above general formula (I), Z ₁ and Z ₂
Are each independently substituted or unsubstituted 5 or 6
Represents the atoms necessary to complete a membered-ring heterocyclic nucleus. These are substituted or unsubstituted thiazole nuclei, quinoline nuclei,
It includes a tellurazole nucleus, a pyridine nucleus, a thiazoline nucleus, an oxazole nucleus, a selenazole nucleus and the like. These nuclei may be substituted by a number of groups known as substituents of said nuclei. These substituents include sulfo, halogen (eg chloro, fluoro), alkyl of 1 to 12 carbon atoms (preferably about 1 to 4 carbon atoms, eg methyl, ethyl, butyl, etc. Is optionally substituted with a known component such as hydroxy, halogen or sulfo), alkoxy having 1 to 12 carbon atoms (preferably about 1 to 4 carbon atoms, for example, methoxy, ethoxy, butoxy), carboxy, Included are carboxylates of 1 to 4 carbon atoms (eg methyl ester, ethyl ester, etc.), sulfonamides or carbonamides.

R ₁ and R ₂ each independently represent a substituted or unsubstituted alkyl having 1 to 20 carbon atoms (preferably 1 to 6 carbon atoms). Examples of alkyl include methyl, ethyl, propyl, isopropyl, butyl, octyl and the like, and substituted alkyl groups (preferably substituted lower alkyl of 1 to 6 carbon atoms) such as hydroxyalkyl groups (eg β-hydroxyethyl, γ-hydroxypropyl, δ-hydroxybutyl etc.), carboxyalkyl group (eg β-carboxyethyl, γ-carboxypropyl etc.), sulfoalkyl group (eg β-sulfoethyl, δ-sulfopropyl, γ-sulfobutyl, δ- Sulfobutyl etc.), a sulfate alkyl group (eg β-sulfateethyl, γ-sulfatepropyl etc.) or an acyloxyalkyl group (β-acetoxyethyl, γ-acetoxypropyl, γ-propoxypropyl etc.).

L _{1 to} L ₅ may be unsubstituted (that is, --CH =) or may be a known substituent (for example, 1 to L).
It may be substituted with alkyl of 12 carbon atoms (eg methyl, ethyl, butyl etc.), aryl (eg phenyl), halogen (eg chloro, fluoro), heterocyclic groups etc.). Furthermore, the substituents on the methine group may form cross-links. For example, the L ₂ , L ₃ and L ₄ methine groups may be bridged to form a 6 membered substituted or unsubstituted carbocycle. Similarly, the L ₃ , L ₄ and L ₅ methine groups may also be bridged to form a 5 or 6 membered substituted or unsubstituted carbocycle.

Preferred infrared sensitizing dyes that can be used in the present invention include those represented by the following general formula (II).

[Chemical 6]

In the formula, Z ₃ and Z ₄ each independently represent an atom necessary to complete a substituted or unsubstituted thiazole nucleus, a substituted or unsubstituted oxazole nucleus, or a substituted or unsubstituted selenazole nucleus. . Q represents an atom necessary to complete a substituted or unsubstituted 5- or 6-membered carbocycle. R ₁ and R ₂ each independently represent a substituted or unsubstituted alkyl group. R ₃ is hydrogen, alkyl of 1 to 4 carbon atoms, aryl, cyano,
Represents halogen or NR ₄ R ₅ , R ₄ and R ₅ each independently represent alkyl or aryl having 1 to 6 carbon atoms, or together represent a substituted or unsubstituted 5- or 6-membered heterocycle; Represents a non-metal atom required to form. X ⁻ represents an anion, n is an integer of 1 to 2,
N is 1 when the dye forms an inner salt.

In the general formula of the preferred infrared sensitizing dye of the present invention, Z ₃ and Z ₄ are each independently a substituent or an unsubstituted thiazole nucleus or an oxazole nucleus or a substituted or unsubstituted selenazole nucleus. Represents a necessary atom. These nuclei may be substituted by a number of groups known as substituents of said nuclei. These include sulfo, halogen (eg chloro, fluoro),
An alkyl of 1 to 12 carbon atoms (preferably about 1 to 4 carbon atoms, such as methyl, ethyl, butyl, etc.,
They may themselves be substituted with known components such as hydroxy, halogen or sulfo), alkoxy of 1 to 12 carbon atoms (preferably about 1 to 4 carbon atoms such as methoxy, ethoxy, butoxy), carboxy. , 1-4
Carboxylates of carbon atoms of (eg, methyl ester, ethyl ester, etc.), sulfonamides or carbonamides. Examples of useful nuclei for Z ₃ and Z ₄ include thiazole nuclei (eg, thiazole, 4-methylthiazole, 4-methylthiazole, 5-methylthiazole, 5-
Phenylthiazole, 4,5-dimethylthiazole, 4,5-diphenylthiazole, 4- (2-thienyl) -thiazole, benzothiazole, 4-chlorobenzothiazole, 5-chlorobenzothiazole, 6-chlorobenzothiazole, 7- Chlorobenzothiazole, 4-methylbenzothiazole, 5-methylbenzothiazole, 6-methylbenzothiazole, 5-
Bromobenzothiazole, 6-bromobenzothiazole,
5-phenylbenzothiazole, 6-phenylbenzothiazole, 4-methoxybenzothiazole, 5-methoxybenzothiazole, 6-methoxybenzothiazole, 5-iodobenzothiazole, 6-iodobenzothiazole, 4-ethoxybenzothiazole, 5- Ethoxybenzothiazole,
Tetrahydrobenzothiazole, 5,6-dimethoxybenzothiazole, 5,6-dioxymethylenebenzothiazole,
5-hydroxybenzothiazole, 6-hydroxybenzothiazole, naphtho- (2,1-d) thiazole, naphtho- (1,2-d)
Thiazole, 5-methoxynaphtho (2,3-d) thiazole, 5-
Ethoxynaphtho (2,3-d) thiazole, 8-methoxynaphtho
(2,3-d) thiazole, 7-methoxynaphtho (2,3-d) thiazole, 4'-methoxythianaphtheno-7 ', 6'-4,5-thiazole and the like) or oxazole nuclei (for example 4- Methyloxazole, 4-phenyloxazole, 5-methyloxazole, 4,5-diphenyloxazole, 4-ethyloxazole, 4,5-dimethyloxazole, 5-phenyloxazole, etc.), benzoxazole nuclei (eg, benzoxazole, 5- Chlorobenzoxazole, 5-methylbenzoxazole, 5-phenylbenzoxazole, 6-methylbenzoxazole, 5,6-dimethylbenzoxazole, 4,6-dimethylbenzoxazole, 5-methoxybenzoxazole, 5-ethoxybenzoxazole, 5-chlorobenzoxazole, 6-methoxybenzoxazole, 5-hydroxybenzoxazole, 6-hydroxy Cibenzoxazole etc.), naphthoxazole nuclei (for example, α-naphthoxazole, β-naphthoxazole etc.), selenazole nuclei (for example, 4-methylselenazole, 4-phenylselenazole, 5-methylselenazole,
4,5-diphenyl-selenazole, 4-ethylselenazole, 4,5-dimethylselenazole, 5-phenylselenazole, etc.), benzoselenazole nuclei (eg, benzoselenazole, 5-chlorobenzoselenazole, 5 -Methylbenzoselenazole, 5-phenylbenzoselenazole, 6-methylbenzoselenazole, 5,6-dimethylbenzoselenazole, 4,6-dimethylbenzoselenazole, 5-methoxybenzoselenazole, 5-ethoxybenzoselena Zol, 5-
Chlorobenzoselenazole, 6-methoxybenzo-selenazole, 5-hydroxybenzoselenazole, 6-hydroxybenzoselenazole, etc.), naphthoselenazole nucleus, etc. (eg α-naphthoselenazole, β-naphthoselenazole etc.) Be done.

R ₁ and R ₂ each independently represent a substituted or unsubstituted alkyl, as defined in general formula (I) above.

R ₃ is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms (eg methyl, ethyl, propyl etc.), an aryl group (eg phenyl), cyano, halogen (eg chloro, bromo, fluoro) or --NR. ₄ represents R ₅ ,
In the formula, R ₄ and R ₅ are each independently an alkyl group having 1 to 6 carbon atoms (eg, methyl, ethyl, propyl),
Represents an aryl group (eg, phenyl, p-methoxyphenyl), or together, is substituted or unsubstituted 5 or 6
Represents a non-metal atom necessary to form a membered-ring heterocyclic group. Preferably, the above heterocyclic group is a heteroaromatic ring containing two conjugated double bonds in the ring. The aromatic character of the heterocycle is known in the chemical journals, for example, SHPine, "Organic Chemistry," 4th Edition, MacGraw-Hill Book Company, p. 703 (1987).
Year). The ring may be substituted as is known in the art. Examples of the substituents are, for example, alkyls having 1 to 4 carbon atoms (eg, methyl, ethyl, butyl) and the like, which may themselves be substituted with a known component such as hydroxy and halogen. Groups (eg hydroxyethyl, chloroethyl), carboxylates of 1 to 4 carbon atoms (eg
Methyl ester, ethyl ester), amide, sulfonamide, halogen (eg chloro, fluoro) and other groups known to those skilled in the art. 5-membered ring N-
Preferred examples of containing aromatic rings include pyrazole, triazole, imidazole and pyrrole.

Q represents an atom necessary to complete a substituted or unsubstituted 5- or 6-membered carbocycle. This ring may be substituted as is known to those skilled in the art. Examples of substituents include substituted or unsubstituted alkyl of 1 to 12 carbon atoms (eg methyl, ethyl, propyl, chloroethyl, benzyl), substituted or unsubstituted aryl (phenyl, p-chlorophenyl), halogen (eg Chloro, fluoro), hydroxy, alkoxy (eg methoxy,
(Ethoxy) and other conventional dye substituents as would be apparent to those skilled in the art.

[0030] X ^- an anion represented by is not particularly limited, for example, a halogen ion (chloride, bromide, iodine), p-toluenesulfonate (PTS ^-), ethyl sulfonate, perchlorate Etc.

In the present invention, when the term "group" is used to describe a chemical compound or a substituent, the described chemical material includes a basic group and a group having a usual substituent. When the term "moiety" is used to describe a chemical compound, or substituent, only non-substituted chemical material is intended to be included. For example, an “alkyl group” includes not only an alkyl moiety (eg, methyl, ethyl, octyl, stearyl, etc.) but also a moiety having a substituent (eg, halogen, cyano, hydroxyl, nitro, amine, carboxylate, etc.). On the other hand,
"Alkyl moiety" includes only methyl, ethyl, octyl, stearyl, cyclohexyl and the like.

Examples of infrared absorbing dyes according to the present invention include those listed below. However, the scope of the present invention is not limited to these.

Dye 1

[Chemical 7]

Dye 2

[Chemical 8]

Dye 3

[Chemical 9]

Dye 4

[Chemical 10]

Dye 5

[Chemical 11]

Dye 6

[Chemical 12]

Dye 7

[Chemical 13]

Dye 8

[Chemical 14]

Dye 9

[Chemical 15]

Dye 10

[Chemical 16]

Dye 11

[Chemical 17]

Dye 12

[Chemical 18]

Dye 13

[Chemical 19]

Dye 14

[Chemical 20]

Dye 15

[Chemical 21]

Dye 16

[Chemical formula 22]

The infrared sensitizing dye used in the present invention can be prepared according to procedures known in the art.
The procedure is, for example, by James, "The Theory
The Theory of Pho
to graphic Processes) ", 4th edition, McMilan (197
7 years), U.S. Pat.Nos. 2,734,900, 3,148,187 and 2,89
5,955 and 3,423,207, Canadian Patent 56-11457
No. 1 and Journal of Organic Chemistry (J. Org. Chem), Vol. 42, page 885 (1977). In addition, the synthetic technology is Slominsky (YL
Slominskii) et al., UKR. Khim. Zh., 40, 625-62.
P. 9 (1974) and Zh. Org. Khim., 15, p. 400 (1979).
It is described in. The method for preparing the dye is described in the examples below. Alterations in the structure of the final dye may be made using these altering methods by selecting the appropriate reagents.

The infrared sensitizing dyes used in the present invention are silver halide emulsions above 700 nm, especially 750 to 850 n.
It is spectrally sensitized to m radiation to provide photographic elements particularly suitable for many commercially available laser diodes. Furthermore, in addition to sensitizing to the desired wavelength range, the sensitizing dyes used in this invention have increased stability of their solutions during storage.

The infrared sensitizing dye used in the present invention is based on 1 mol of silver in the specific layer sensitized by the dye.
5 × 10 ⁻⁷ mol to 5 × 10 ⁻³ mol, preferably 1 × 10 ⁻⁶ mol to 1
It is added to the silver halide photographic emulsion layer in a content of x10 ^-3 mol, more preferably 2 x 10 ^-6 mol to 5 x 10 ^-4 mol.

Another embodiment of the present invention is a silver halide photographic element comprising a support, one or more infrared sensitized silver halide emulsion layers and one or more hydrophilic colloid non-photosensitive layers. Infrared sensitized silver halide emulsion layers of to provide photographic elements containing infrared sensitizing dyes and stabilizing amounts of organic reducing agents and alkaline buffers.

Examples of silver halide photographic materials suitable for this invention include black and white and color photographic elements.

Infrared sensitized silver halide color photographic elements used in this invention are preferably those described in US Pat.
No. 619,892, the contents of which are incorporated herein by reference. More preferably, the infrared sensitized silver halide color photographic element used in the present invention is
All silver halide emulsion layers were sensitized to the infrared region of different electromagnetic spectrum. The order of these layers relative to the support, the difference in emulsion sensitivity between layers, and the sensitivity, contrast and Dmax of each layer are preferably as described in US Pat. No. 4,619,892.

The dyes used in this invention have been found to be particularly useful in spectrally sensitizing infrared radiation to silver halide emulsion layers in photographic elements containing one or more other infrared sensitive silver halide layers. A preferred example of the photographic element comprises three or more silver halide emulsion layers on a substrate, each layer forming a dye of a different color upon reaction with a different photographic color imageable material, such as an oxidized color photographic developer. Associated with a possible color coupler, diffusible dye, bleaching dye or oxidizing leuco dye, three emulsion layers are sensitized to three different parts of the visible spectrum, one or more layers, preferably two or more layers. Is sensitized with radiation in the infrared region of the spectrum.

Various types of silver halide photographic emulsions may be used in the practice of this invention. Silver chloride, silver bromide, silver iodobromide, silver bromide, silver chloride iodobromide, and mixtures thereof may be used, for example dispersed in a hydrophilic colloid or carrier.

The silver halide grains of photographic emulsions have a regular crystal structure (eg cubic, octahedral and monohedral).
It may be a regular grain having a tetrahedron or the like), a spherical or irregular crystal structure, a crystal defect such as a twin plane, a plate-like one, or a combination thereof.

Photographic elements containing layers containing the dyes of this invention may be coated with suitable support materials used in the photographic art such as cellulose acetate, nitrocellulose, paper, polyesters (polyethylene terephthalate, etc.).

Gelatin is useful as a binder or protective colloid for use in photographic elements,
Other hydrophilic colloids alone or in gelatin (eg gelatin substitutes), collodion, gum arabic, cellulose ester derivatives (eg carboxylated cellulose alkyl esters), hydroxyethyl cellulose, carboxymethyl cellulose, synthetic resins (eg US Pat. No. 2,949,442). And the like), polyvinyl alcohol, and others known in the art.

The colloid may be partially hardened or fully hardened using various known photographic hardeners. The curing agents are free aldehydes, aldehyde-releasing compounds, triazines and diazines, and include aziridines, vinyl sulfones, carbodiimides, etc. , 3
25,287, 3,992,366, 3,271,175 and 3,49
It may be used as described in No. 0,911.

The silver halide photographic elements can be used to form dye images by the selective formation of dyes. The photographic elements described above for silver image formation can be used to form dye images by using developers containing dye image-forming agents (e.g. color couplers) (e.g. U.S. Pat.Nos. 3,111,864 and 3,002,836). , No. 2,271,238, No. 2,2
36,598, 2,950,970, 2,592,243, 2,343,70
No. 3, No. 2,376,380, No. 2,369,489, No. 2,899,306,
3,152,896, 2,115,394, 2,252,718, 2,1
08,602 and 3,547,650). In this form, the developer contains a color developer (eg, a primary aromatic amine whose oxidized form is capable of reacting with a coupler to form an image dye). Also, instant self-developing diffusion transfer films can be used, similar to photographic color films or paper, with the silver halide in catalytic proximity with a source of reducing silver and a leuco dye.

Dye-forming couplers may be added to the photographic element as described in, for example, Schneider et al., "Die Chemie", No. 57.
Vol. 113, 1944, and U.S. Pat. No. 2,304,940.
No., No. 2,269,158, No. 2,322,027, No. 2,376,679,
2,801,171, 2,748,141, 2,772,163, 2,8
35,579, 2,533,514, 2,353,754, 3,409,43
No. 5 and Chemical Research Disclosure (Che
Research Disclosure), Volume 159, Item 15930 (1977)
(July 1). Dye-forming couplers may be added in different amounts to obtain different photographic effects. For example, British Patent No. 923,045 and U.S. Pat.No. 3,843,369 teach that the concentration limit of the coupler, in connection with silver coverage, should be less than that commonly used in fast or medium speed emulsion layers. There is.

Dye-forming couplers are generally subtractive primary colors (ie, yellow, magenta, and cyan).
Non-diffusive colorless couplers selected to form image dyes, eg, hydrophobically ballasted, open-chain ketomethylenes, pyrazolones, pyrazolotriazoles, pyrazolobenzes for addition to high boiling organic (coupler) solvents. Imidazole, phenol and naphthol type 2
And a 4 equivalent coupler. The coupler is, for example, U.S. Patent Nos. 2,423,730, 2,772,162, and 2,895,
826, 2,710,803, 2,407,207, 3,737,316
No. 2,367,531, No. 2,772,161, No. 2,600,788,
3,006,759, 3,214,437, 3,253,924, 2,8
75,057, 2,908,573, 3,043,892, 2,474,29
No. 3, No. 2,407,210, No. 3,062,653, No. 3,265,506,
3,384,657, 2,343,703, 3,127,269, 2,8
65,748, 2,933,391, 2,865,751, 3,725,06
No. 7, No. 3,758,308, No. 3,779,763, No. 3,785,829,
Same 3,762,921, same 3,983,608, same 3,311,467, same 3,4
08,194, 3,408,194, 3,458,315, 3,447,92
No. 8, No. 3,476,563, No. 3,419,390, No. 3,419,391,
3,519,429, 3,222,176, 3,227,550, British Patents 969,921, 1,241,069, 1,011,940, 9
75,928, 1,111,554, 1,248,924 and Canadian Patent 726,651. Dye-forming couplers of different reaction coefficients in a single or separate layers may be used to achieve the desired effect for a particular photograph.

Dye-forming couplers in couplings are photographic-useful fragments such as development inhibitors or accelerators, bleach accelerators, development aids, silver halide solvents, toners, hardeners, fogging agents, fog. Inhibitors, competitive couplers, chemical or spectral sensitizers and desensitizers may be released. Development inhibitor releasing (DIR) couplers are described in U.S. Pat. Nos. 3,148,062, 3,227,554, and US Pat.
3,733,201, 3,617,291, 3,703,375, 3,61
5,506, 3,265,506, 3,620,745, 3,632,345
No. 3, No. 3,869,291, No. 3,642,485, No. 3,770,436,
No. 3,808,945 and British Patent No. 1,201,110 and
It is explained in No. 1,236,767. Dye-forming couplers and non-dye-forming compounds that release various photographically useful groups in coupling are described in U.S. Pat. No. 4,248,962.
No. DIR compounds which do not form a dye upon reaction with an oxidized color developer are disclosed in, for example, U.S. Pat. Nos. 3,928,041, 3,958,993 and 3,961,959,
No. 4,049,455, No. 4,052,213, and German OLS No. 2,52
It can be used as described in 9,350, 2,448,063, and 2,610,546. U.S. Pat.No. 3,379,529
Nos. 3,043,690, 3,364,022, 3,297,445 and 3,287,129, oxidatively cleaving DIR compounds may be used. Relatively less sensitive silver halide emulsions (Lippmann used as an intermediate or overcoat layer to avoid or control migration of development-inhibiting fragments, as described, for example, in U.S. Pat.No. 3,892,572). ) Emulsion) may be used.

Color dye-forming couplers in photographic elements (eg, those used to form integral masks for negative color images)
, For example, U.S. Patent Nos. 2,449,966 and 2,521,908,
3,034,892, 3,476,563, 3,519,429, 2,5
43,691, 3,028,238, 3,061,432, and / or a competitive coupler may be added to U.S. Patents 3,876,428, 3,580,722, 2,998,314.
No. 2, No. 2,808,329, No. 2,742,832 and No. 2,689,793
It may be added as described in No.

As described above, the color provided in an image produced by exposing each of the separately sensitized silver halide emulsion layers is not necessarily produced by a color coupler reaction with an oxidized color developer. May be. Many other color image forming mechanisms known in the art may be used. Commercially available color imageable mechanisms include dye diffusion transfer, dye bleaching and leuco dye oxidation. Each of these procedures is used in commercially available products, known to those skilled in the art, and used with silver halide emulsions. Also, multicolor elements using these different technologies are commercially available. Converting a conventional commercially available system into practice of the present invention is by routinely changing the parameters of the sensitometer of the system, and / or
Alternatively, it may be done by adding an intermediate filter layer as described in US Pat. No. 4,619,892. For example, in a conventional instant color dye diffusion transfer element, the sensitivity of the various layers and / or the placement of the filter layers between the silver halide emulsion layers is shown by the above-referenced U.S. Pat. But the same is true. In the element it can be either a negative active or a positive active silver halide emulsion.
The only major and fairly obvious requirement that must be placed on such a structure is that the placement of the filter layer does not interfere with the migration of the diffusion dye to the receptor layer within the element. Using a filter that is not a barrier layer between the receptor layer and the dye-containing layer is the simplest way to meet this requirement. Such a layer does not interfere with the migration of the diffusing dye across the filter.

Imaging systems of this type are known in the art. For more information on the various dye transfer and diffusion processes, see, for example, "A Fundamentally New Imaging Technology for Instant Photography (A Fundamentally New Imagi
Technology for Instant Photography), Harrison
(WT Harison, Jr.), Photographic Science,
And Engineering, Volume 20, Issue 4 (July 1976/8
Mon), and Neblette's "Handbook
Of Photography and Reprography, Materials, Process and Systems (Handbook of Ph
otography and Reprography, Materials, Processes an
d Systems), 7th Edition, John M. St.
unge), Van Nostrand Rainhold Company
(van Nostrand Reinhold Company), New York, No. 324
Pp. 330, and 126 (1977). For more information on dye bleached color imaging systems, see The Reproduction of Color.
Color), 3rd Edition, RWGHunt, Fountain Press, London, UK, pages 325-330 (1975), and The Theory of the Photographic Process. , 4th Edition, Meads & James
(Mees and James), McMilan, New York, No. 363
You may also refer to pages 366 (1977). Details on the dye transfer process are also described in Mease and James, pages 366-372, supra. Leuco dye oxidation in silver halide systems is described in U.S. Pat. No. 4,460,681.
No. 4,374,821, and No. 4,021,240. The diffusion thermographic color imageable system disclosed in British Patent Application No. 3,100,458 is also useful in the practice of this invention.

The photographic elements may contain image dye stabilizers. Such image dye stabilizers include U.S. Pat.Nos. 3,423,300, 3,698,909, 3,574,627 and 3,5.
73,050, 3,764,337 and 4,042,394 and British Patent 1,326,889.

The photographic elements may include filter dyes. The dyes should be selected based on their radiation filtering properties to ensure that they filter the appropriate wavelengths. Filter dyes and methods for adding them to photographic elements are known and are described, for example, in US Pat.
4,440,852, 3,671,648, 3,423,207 and
2,895,955, British Patent 485,624 and Research Disclosure, Volume 176, Item 17643 (1978, 12
Month). Filter dyes may be used in the practice of the invention to provide room light steerable elements. Dyes that are impermeable to radiation having a wavelength shorter than the shortest wavelength to which one of the emulsion layers is sensitized may be used in one or more (preferably all) layers of the emulsion layer. The cut-off filter dye preferably does not transmit light at wavelengths greater than about 50 nm and less than the shortest wavelength sensitized by any of the emulsion layers. Also, filter dyes should have non-fading (ie non-migratory) properties and be decolorizable (eg by bleaching or heating in the developer) or leachable (eg removed by solvent reaction in the bath). Better have it.

Other conventional photographic additives such as coating aids, antistatic agents, high-sharpness dyes, antihalation dyes and layers, antifoggants, latent image stabilizers,
A supersensitizer, an anti-kinking agent, a high-brightness reciprocity law reducing agent, etc. may be added.

A method for producing the element, infrared sensitizing means, additives (for example, chemical sensitizers, antifoggants and stabilizers, desensitizers, optical brighteners, couplers, curing agents, coating aids, plasticizers) Agents, brighteners, matting agents, high-boiling organic solvents, development accelerator compounds, antistatic agents, stain inhibitors, etc.)
For more information on how to use
Volume 176, No. 17643, December 1979, Sections I-XIV.

The following examples describe non-limiting examples of stabilizing treatments of solutions of infrared sensitizing dyes and preferred embodiments of the invention.

[0073]

Example 1 Sample 1 (reference) 0.1 g of spectral sensitizing dye 4 was dissolved in 10 ml of 2-phenoxyethanol, and the resulting solution was diluted to 20 ml at 100 ml with methanol.

Sample 2 (reference) Prepared as sample 1 except that the methanolic solution contained 250 mg of sodium acetate.

Sample 3 (Reference) Prepared as Sample 1 except that the methanolic solution contained 100 mg of ascorbic acid.

Sample 4 (Invention) 100 mg of ascorbic acid and 250 mg in a methanolic solution
Was prepared in the same manner as in Sample 1, except that sodium acetate was added.

Sample 5 (Invention) 200 mg of ascorbic acid and 250 mg in a methanolic solution
Was prepared in the same manner as in Sample 1, except that sodium acetate was added.

Sample 6 (Invention) 50 mg of ascorbic acid and 250 mg in a methanolic solution
Was prepared in the same manner as in Sample 1, except that sodium acetate was added.

Sample 7 (invention) 30 mg of ascorbic acid and 250 mg in a methanolic solution
Was prepared in the same manner as in Sample 1, except that sodium acetate was added.

Sample 8 (invention) 100 mg of ascorbic acid and 150 mg in a methanolic solution
Was prepared in the same manner as in Sample 1, except that sodium acetate was added.

Sample 9 (Invention) 100 mg of ascorbic acid and 350 mg in a methanolic solution
Was prepared in the same manner as in Sample 1, except that sodium acetate was added.

The stability of the solutions of Samples 1-9 was obtained by further diluting the freshly prepared solutions with ethanol (1: 500,000) and after 48 hours storage by measuring the optical density at λ max. Table 1 below shows the percentage of the optical density measured after 48 hours of storage relative to the optical density measured in the freshly prepared solution.

[0083]

[Table 1]

A solution may be considered stable if the values obtained are above 90% of the initial value, preferably above 95% and there is no precipitation of the solution. The presence of precipitates in the solution renders it useless to add the solution to silver halide photographic materials. Table 1 shows that Samples 4-9 are useful in the present invention.

Example 2 Sample 10 (Reference) Prepared as Sample 1 of Example 1 except that the spectral sensitizing dye 4 was replaced with an equimolar amount of dye 16.

Sample 11 (Invention) Prepared as Sample 4 of Example 1 except that the spectral sensitizing dye 4 was replaced with an equimolar amount of dye 16.

Sample 12 (reference) Prepared as Sample 1 of Example 1 except that the spectral sensitizing dye 4 was replaced by an equimolar amount of dye 15.

Sample 13 (Invention) Prepared as Sample 4 of Example 1 except that the spectral sensitizing dye 4 was replaced with an equimolar amount of dye 15.

The stability measured in the same manner as in Example 1 is shown in Table 2.

[0090]

[Table 2]

Example 3 Film 1 (reference) 1000 g of AgBr emulsion (average grain size 0.26 μm
m, having a silver coverage of 13% and a silver / gelatin ratio of 1.25) was added with stirring at 50 ° C. to 466 ml of water containing 6 ml of 1N NaOH solution. After that, Hostapu (Ho
stapur) SAS (Alkanesulfonic acid sodium salt type anionic surfactant, Hoechst AG) 10% (w /
w) A mixture of 7.5 ml of an aqueous solution and 1.75 ml of a 50% (w / w) aqueous solution of glycerin was added. After that, supersensitizer S
117 ml of a 1% (w / w) aqueous solution of S and 115 ml of 0.025% (w / w) freshly prepared solution of spectral sensitizing dye 16 were added. The composition was held at 50 ° C for 30 minutes with stirring. Then 40ml of 20% (w / w) aqueous polyethyl acrylate latex, lauryl sulphate sodium salt type surfactant and 3.7% formaldehyde 1
0 ml of aqueous solution was added. The composition was coated on a conventional photographic paper base with a silver coverage of 2.2 g / m ² . The photographic layer was overcoated with a protective layer containing gelatin, a surfactant and a bis-vinylsulfonyl type hardener.

Film 2 (Invention) Film 2 was prepared as film 1 except that 0.1% ascorbic acid and 0.25% sodium acetate solution were added to a freshly prepared solution of spectral sensitizing dye 16. Transfer the film to an EDG sensitometer, medium density filter
(Wratten ^R ) 87 filter (commercially available from Eastman Kodak Company), exposed through standard step-wedge, developed in 3M XAD / 2 developer at 35 ° C for 27 seconds, fixed at 30 ° C for 27 seconds. , Tap water for 22 seconds, 35 ℃
And washed in a Trimatic ^™ XP515 roller transport processor for 22 seconds at 35 ° C. Photosensitivity results expressed in Dmin and sensitivity are shown in Table 3. Sensitivity value is LogE (E is above Dmin
The exposure dose measured at a density of 1.0 is mcs (meter-cand
le-seconds).

[0093]

[Table 3]

Table 3 shows that the film 2 of the invention containing a freshly prepared solution of the spectral sensitizing dye stabilized by ascorbic acid and sodium acetate was used as a reference sample in which the freshly prepared solution of the spectral sensitizing dye was not stabilized. By comparison, it is shown that the sensitivity is appropriately improved while maintaining the same Dmin value. As a matter of course, the degree of improvement in the sensitivity of Film 2 is as follows. Reference film 1 added to a silver halide emulsion of
Greater than the sensitivity of.

Example 4 Film 3 (reference) 29 g of AgCl emulsion (0.45 μm average particle size, 9.1%
Of Ag and 5.47% gelatin) of 120 g of oil-in-water dispersion containing 7.2 g of coupler M and 6.72 g of gelatin were added. The composition was diluted with 230 ml of water and 3% gelatin was added. Then 0.1% (w / w) freshly prepared solution of Spectral Sensitizing Dye 4 in 9: 1 (vol / vol) methanol / phenyl cellosolve solvent mixture 1.
65g, 0.515g Stabilizer ST and 0.0145g Supersensitizer S
S was added to the composition. The composition was then held at 38 ° C for 40 minutes. After that, 0.1% of antifoggant AF
0.75 g of (w / w) aqueous solution was added. The composition was coated on a conventional photographic paper base with a silver coverage of 0.28 g / m ² . The photographic layer was overcoated with a protective layer containing gelatin, a surfactant and a bis-vinylsulfonyl type hardener.

Film 4 (Invention) Prepared as film 3 except that 10% ascorbic acid and 0.25% sodium acetate were added to a freshly prepared solution of spectral sensitizing dye 4. After holding for 72 hours at 33 ° C, each film was placed on a laser diode for 820n.
Exposed at m. Exposure coating Kodak
Developed on the RA-4 processing line. Table 4 shows the exposure results expressed in Dmin and sensitivity.

[0097]

[Table 4]

Table 4 shows that the film 4 of the present invention containing a freshly prepared solution of the spectral sensitizing dye stabilized by ascorbic acid and sodium acetate is slightly improved in terms of sensitivity while keeping the same value of Dmin. Indicates that. As in Example 3, after preparing a solution of the spectral sensitizing dye, 48
A more significant improvement in sensitivity may be obtained if added after more than an hour.

Coupler M

[Chemical formula 23]

Stabilizer ST

[Chemical formula 24]

Supersensitizer SS

[Chemical 25]

Antifoggant AF

[Chemical formula 26]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Antonio Ruzzi Italy 17016 Ferrania (Savona) (No street number) Three-M Italia Richelche Societa Pell Achoni (72) Inventor Stefania Girardo Italy 17016 Ferrania (Savona) (No street number displayed) 3M Italy Italy Richerche Societa Pell Achioni

Claims (17)

[Claims] 1. A solution of infrared sensitizing dye in a stabilizing amount of a) an organic reducing agent selected from the group consisting of ascorbic acid, ascorbic acid isomers, glucose, cyclodextrin and mixtures thereof, and b). A method for stabilizing a solution of an infrared sensitizing dye, which comprises adding an organic or inorganic buffer. 2. The method for stabilizing an infrared sensitizing dye solution according to claim 1, wherein the organic reducing agent is ascorbic acid. 3. A solution 1 containing 0.1% by weight of an infrared sensitizing dye.
The method for stabilizing an infrared sensitizing dye solution according to claim 1, wherein an organic reducing agent is added in an amount of 5 to 1000 mg per 00 ml. 4. A solution 1 containing 0.1% by weight of an infrared sensitizing dye.
The method for stabilizing an infrared sensitizing dye solution according to claim 1, wherein an organic reducing agent is added in an amount of 10 to 300 mg per 00 ml. 5. The method for stabilizing an infrared sensitizing dye solution according to claim 1, wherein the buffer is sodium acetate. 6. A solution 1 containing 0.1% by weight of an infrared sensitizing dye.
The method for stabilizing an infrared sensitizing dye solution according to claim 1, wherein the buffer is added in an amount of 20 to 1000 mg per 00 ml. 7. A solution 1 containing 0.1% by weight of an infrared sensitizing dye.
The method for stabilizing an infrared sensitizing dye solution according to claim 1, wherein a buffering agent is added in an amount of 100 to 500 mg per 00 ml. 8. A method for stabilizing an infrared sensitizing dye solution according to claim 1, wherein the infrared sensitizing dye is represented by the following general formula: (Wherein, Z ₁ and Z ₂ represent the atoms necessary to complete a 5 or 6-membered ring heterocyclic nucleus independently, R ₁
And R ₂ each independently represents an alkyl group, L ₁ ,
L ₂ , L ₃ , L ₄ and L ₅ each independently represent a methine group, X ⁻ represents an anion, n represents an integer of 1 to 2, and the dye forms an inner salt. In which n is 1 and p and q each independently represent 0 or 1.
And z represents 2.) 9. The method for stabilizing an infrared sensitizing dye solution according to claim 1, wherein the infrared sensitizing dye is represented by the following structural formula: (In the formula, Z ₃ and Z ₄ each independently represent an atom necessary for completing a thiazole nucleus, an oxazole nucleus, or a selenazole nucleus, and Q represents an atom necessary for completing a 5- or 6-membered carbocycle. R ₁ and R ₂ each independently represent an alkyl group, R ₃ is hydrogen, alkyl,
Represents aryl, cyano, halogen, or —NR ₄ R ₅ ,
R ₄ and R ₅ each independently represent alkyl or aryl, or represent a nonmetallic atom necessary for forming a 5- or 6-membered heterocycle together, X ⁻ represents an anion, n represents an integer of 1-2, and n is 1 when the dye forms an intramolecular salt). 10. R ₃ is pyrazole, triazole,
The method for stabilizing an infrared sensitizing dye solution according to claim 9, which represents an atom selected from the group consisting of imidazole and pyrrole and necessary for completing a 5-membered N-containing aromatic ring. 11. A silver halide photographic element comprising a support, one or more infrared sensitized silver halide emulsion photographic layers and one or more hydrophilic colloid non-photosensitive layers,
One or more infrared sensitizing layers, an organic reducing agent selected from the group consisting of infrared sensitizing dyes, ascorbic acid, ascorbic acid isomers, glucose, cyclodextrin, and mixtures thereof, and an organic or inorganic buffer A silver halide photographic element containing an agent. 12. The organic reducing agent is ascorbic acid,
A silver halide photographic element according to claim 11. 13. A silver halide photographic element according to claim 11, wherein the buffering agent is sodium acetate. 14. A silver halide photographic element according to claim 11, wherein the infrared sensitizing dye is represented by the following general formula: (Wherein, Z ₁ and Z ₂ represent the atoms necessary to complete a 5 or 6-membered ring heterocyclic nucleus independently, R ₁
And R ₂ each independently represents an alkyl group, L ₁ ,
L ₂ , L ₃ , L ₄ and L ₅ each independently represent a methine group, X ⁻ represents an anion, n represents an integer of 1 to 2, and the dye forms an inner salt. In which n is 1 and p and q each independently represent 0 or 1.
And z represents 2.) 15. A silver halide photographic element according to claim 11, wherein the infrared sensitizing dye is represented by the following general formula: (In the formula, Z ₃ and Z ₄ each independently represent an atom necessary for completing a thiazole nucleus, an oxazole nucleus or a selenazole nucleus, and Q is necessary for completing a 5- or 6-membered carbocycle. Represents an atom, R ₁ and R ₂ each independently represent an alkyl group, R ₃ represents hydrogen, 1 to 4
Represents an alkyl, aryl, cyano, halogen or —NR ₄ R ₅ of a carbon atom of R ₄ and R ₅ are each independently an alkyl or aryl of a carbon atom of 1 to 6 or a 5- or 6-membered ring together. Represents a non-metal atom necessary to form a heterocycle, X ⁻ represents an anion, and n is 1 to
Represents an integer of 2 and n is 1 when the dye forms an intramolecular salt). 16. R ₃ is pyrazole, triazole,
A silver halide photographic element according to claim 15 which represents the atoms necessary to complete a 5-membered N-containing aromatic ring selected from the group consisting of imidazole and pyrrole. 17. The amount of dye is 5 × 10 5 per mol of silver.
The halogenated dye element according to claim 11, which is ^{-7 to} 5 x 10 ^-3 mol.