JPH11202457A - Method for dissolution and emulsification and dispersion of photographic hydrophobic material and silver halide photographic sensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the emulsification dispersion method for the solution of the photographic hydrophobic material improved in stability and the photographic hydrophobic material improved in dispersion stability against time lapse and to provide the silver halide photographic sensitive material improved in image storage stability. SOLUTION: An oil phase solution component containing the photographic hydrophobic material in an atmosphere of <=15% oxygen or in the presence of a melting stabilizer or the oil phase solution component containing the photographic hydro-phobic material having an average grain diameter of <=300 μm. The silver halide photographic sensitive material is formed by adding an emulsifier auxiliary and/or a water phase solution containing a water-soluble binder to the oil phase solution obtained by the above dissolution method, and stirred to form water-in-oil type drops, and further continuing addition of water phase solution to convert the water-in-coil phase into an oil-in-water phase, and such a novel emulsification dispersion method is also provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for dissolving an oil phase solution in which the stability of a photographic hydrophobic substance is improved, the stability with time of a dispersion is improved, and a fine oil-in-water emulsion dispersion. The present invention relates to a method for emulsifying and dispersing a photographic hydrophobic substance from which a product is obtained, and a silver halide photographic light-sensitive material using the oil-in-water type emulsifying dispersion.

[0002]

2. Description of the Related Art Silver halide photographic light-sensitive materials are extremely superior to other light-sensitive materials, such as high sensitivity, excellent gradation reproducibility, and inexpensive recording materials. Due to its properties, it is widely used today.

In general, silver halide photographic materials exhibit a color image forming compound, a compound for diffusion transfer, an anti-fading agent, a color image stabilizer, a color mixing inhibitor, an ultraviolet absorber, a fluorescent light, because of the above-mentioned excellent properties. Various photographic hydrophobic substances such as brighteners and high-boiling organic solvents are included.

One of the methods for incorporating such a photographic hydrophobic substance into a silver halide photographic light-sensitive material is to add an oil-in-water emulsion dispersion of the photographic hydrophobic substance together with a hydrophilic binder.

Conventionally, these oil-in-water type emulsified dispersions have been
The photographic hydrophobic substance is mixed with a low-boiling organic solvent and dissolved to form a solution of the photographic hydrophobic substance, which contains a water-soluble binder, for example, gelatin, and an emulsifying aid, for example, containing a surfactant. The oil-in-water emulsion of the photographic hydrophobic substance was prepared by adding and mixing to the aqueous phase solution, and then the oil-in-water emulsion was further dispersed by a dispersing machine such as a colloid mill, a homogenizer, and a homomixer. The oil droplet diameter of the photographic hydrophobic substance was adjusted to a desired level.

In recent years, from the viewpoints of global environmental problems and production costs, it is necessary to reduce the amount of a low boiling organic solvent used in preparing an oil-in-water emulsion used in the silver halide photographic material. Is becoming mandatory.

As methods for obtaining a dispersion of a photographic hydrophobic substance without using a low-boiling organic solvent, there have conventionally been known a method of dispersing a solid as it is, a difference in solubility in a solvent including water and a difference in solubility in pH. A sedimentation dispersion method using a method and a melt dispersion method using a melt of a photographic hydrophobic substance are known.

The present inventors have studied the conventional melt dispersion method among these dispersion methods. As a result, the melt dispersion method involves the following steps: (1) melting a photographic hydrophobic substance once at a temperature higher than its melting point; Due to the process, the photographic hydrophobic substance is decomposed,
The yield is greatly reduced. (2) When a dispersion is prepared using a melt, if the dispersion is stored, decomposition of the hydrophobic photographically useful compound is promoted, and the hydrophobic photographically useful compound is reduced. (3) Decomposition products of the photographic hydrophobic substance generated by melting at a high temperature remain in the silver halide photographic light-sensitive material as a final product, and deteriorate the image storability of the photographic light-sensitive material. (4) The particle size distribution of the dispersion is wide, the stability with time is poor, and large oil droplets (generally, 10 μm or more) are frequently generated, and fatal failure of a photographic photosensitive material called pinhole occurs frequently. (5) Over time, the particle size distribution worsens, the coloring efficiency deteriorates, and the image storability deteriorates. It turned out that it had the fault.

JP-A-57-78038 discloses that a melt of a photographically active substance is used for an organic phase at the time of emulsification and dispersion. There is no recognition of deterioration. Further, the oil droplet diameter is larger than 0.3 μm. Also, Japanese Patent Application Laid-Open No. Sho 60-5534
Nos. 0 and 63-98661 have high solubility in high-boiling organic solvents, dispersibility in photographic emulsions,
Although the structure of the coupler with excellent stability is disclosed,
There is no description of a method for preparing a dispersion without using a low-boiling organic solvent, and no recognition of deterioration of a photographically active substance.

[0010]

Accordingly, a first object of the present invention is to improve the stability of a photographic hydrophobic substance.
An object of the present invention is to provide a method for preparing a dissolved substance of a photographic hydrophobic substance.

A second object of the present invention is to provide a method for emulsifying and dispersing a photographic hydrophobic substance in which the stability with time of the dispersion is improved.

A third object of the present invention is to provide a silver halide photographic material having improved image storability.

[0013]

SUMMARY OF THE INVENTION The object of the present invention is to provide: (1) an oil phase solution component containing at least one photographic hydrophobic substance and containing substantially no co-solvent; A method for dissolving an oil phase solution containing a photographic hydrophobic substance, characterized by dissolving in an atmosphere. (2) A photographic solution characterized by dissolving an oil phase solution component containing at least one photographic hydrophobic substance and containing substantially no co-solvent in the presence of at least one melt stabilizer. A method for dissolving an oil phase solution containing a hydrophobic substance. (3) The melt stabilizer is selected from phenolic antioxidants, phosphoric acid antioxidants, sulfur antioxidants, amine antioxidants, hydroquinone derivatives, higher alcohols and fatty acid esters. The method for dissolving an oil phase solution containing a photographic hydrophobic substance according to the above (2), which is an agent. (4) A photographic hydrophobic substance characterized by containing at least one photographic hydrophobic substance having an average particle diameter of 300 μm or less and dissolving an oil phase solution component substantially not containing an auxiliary solvent. The method of dissolving the oil phase solution. (5) Add an aqueous phase solution containing at least one emulsifying aid and / or a water-soluble binder to an oil phase solution containing at least one photographic hydrophobic substance and containing substantially no auxiliary solvent, and stirring. A water-in-oil type emulsion, further adding an aqueous phase solution, and inverting the phase to produce an oil-in-water type emulsion, wherein the oil phase solution has an oxygen concentration of 15% or less. A method for emulsifying and dispersing a photographic hydrophobic substance, which is obtained by dissolving in an atmosphere. (6) Add an aqueous phase solution containing at least one emulsifying aid and / or a water-soluble binder to an oil phase solution containing at least one photographic hydrophobic substance and containing substantially no auxiliary solvent, and stirring. A water-in-oil type emulsion, further adding an aqueous phase solution, and inverting the phase to form an oil-in-water type emulsion, wherein the oil phase solution has at least one kind of melt stable A method for emulsifying and dispersing a photographic hydrophobic substance, characterized by containing an agent. (7) A melt stabilizer selected from a phenolic antioxidant, a phosphoric acid antioxidant, a sulfuric antioxidant, an amine antioxidant, a hydroquinone derivative, a higher alcohol or a fatty acid ester. The method for emulsifying and dispersing a photographic hydrophobic substance according to the above (6), which is an agent. (8) adding an aqueous phase solution containing at least one emulsifying aid and / or a water-soluble binder to an oil phase solution containing at least one photographic hydrophobic substance and containing substantially no auxiliary solvent; Stir,
An emulsion dispersion method for forming a water-in-oil emulsion, further adding an aqueous phase solution, and inverting the phase to produce an oil-in-water emulsion, wherein the oil phase solution has an average particle diameter of 300 μm or less. A method for emulsifying and dispersing a photographic hydrophobic substance, which is formed by heating and dissolving a powder of a hydrophobic substance. (9) At least one oil-in-water emulsion of a photographic hydrophobic substance formed by the method for emulsifying and dispersing a photographic hydrophobic substance according to any one of the above (5) to (8). Characteristic silver halide photographic material. Achieved by

Hereinafter, the present invention will be described in detail.

The photographic hydrophobic substance (hereinafter sometimes referred to as a hydrophobic compound) according to the present invention includes, for example, a dye image-forming coupler, a dye image-donating redox compound, an antifoggant, a compound for diffusion transfer, and a color. Image stabilizers, color mixture inhibitors, ultraviolet absorbers, fluorescent brighteners, high-boiling organic solvents, silver halide solvents, oil-soluble dyes, nucleating agents, nucleation accelerators, hardeners, developing agents, auxiliary developing agents And other hydrophobic compounds used in silver halide photographic light-sensitive materials.

The dye image forming couplers include, for example, yellow dye forming couplers, magenta dye forming couplers,
And cyan dye-forming couplers.

As the yellow dye-forming coupler, an acylacetanilide coupler can be preferably used. Among them, benzoylacetoanilide compounds and pivaloylacetoanilide compounds are advantageous. Specifically, JP-A-63-85631 and JP-A-63-979.
No. 51, JP-A-1-156748, and 2-2
Illustrative compounds described in JP-A-98943 and the like.

Examples of magenta dye-forming couplers include 5-
Known couplers such as pyrazolone-based, pyrazoloazole-based, and pyrazolobenzimidazole-based couplers can be used.

As the cyan dye-forming coupler, naphthol couplers and phenol couplers can be preferably used.

In addition to these, Japanese Patent Application Laid-Open No. 1-156748
Gazette, JP-A-3-174153, JP-A-3-19603
9 and the like, and imidazole cyan couplers disclosed in JP-A-2-136854 and JP-A-3-1960.
Pyrazoloazole cyan couplers and pyrazoloazine cyan couplers disclosed in JP-A-39-39 and the like, and further, JP-A-3-103848 and JP-A-3-10384.
No. 9 discloses a hydroxypyridine cyan coupler, a hydroxyazine cyan coupler, an aminopyridine cyan coupler disclosed in JP-A-3-206450, and the like. Excellent in terms of.

Examples of the high boiling point organic solvent include, for example, JP-A-1-196048 and JP-A-1-209446.
Examples include the compounds described in JP-A-63-253943.

As the hydrophobic compound, other than the above, for example, Research Disclosure 308119 (198)
9) 998-1011, 17643 (1978) 2
Pages 4 to 27, 18716 (1979) 650 to 651
Page, JP-A-4-114154, 6-67388
Gazette, JP-A-4-81847, and JP-A-3-174150
JP-A No. 1-196049, JP-A No. 4-13305
No. 6, No. 1-250944, No. 4-1633
JP-A-5-165144, JP-A-64-26
No. 854, No. 64-90445, No. 62-1
Nos. 82741 and 64-66646 and 62
JP-A-215272, JP-A-63-46436, U.S. Pat. No. 4,774,187, J.P. Am. Oi
l. Chem. Soc. 54 110 (1977) can also be preferably used.

When dissolving without using a low-boiling organic solvent as an auxiliary solvent, it is known in the art that the temperature is 100 to 150 ° C.
Is generally heated. For example, US Pat.
No. 589,322 describes an example of melting at 100 ° C. or higher. However, it has been found that the prolonged heating at such a high temperature causes a serious disadvantage that the active ingredient of the hydrophobic compound is decomposed.
Further, even in the oil-in-water emulsion produced using the oil phase composition, there is a problem that the storage reduces the residual amount of the active ingredient of the hydrophobic compound.

As a result of investigations made by the present inventors, the above-mentioned drawbacks include the following methods for dissolving a hydrophobic compound: (1) dissolving in an atmosphere having an oxygen concentration of 15% or less; (2) Dissolve using a melt stabilizer. (3) The hydrophobic compound used has an average particle size of 300 μm
Dissolve using the following powder: By doing so, we found that it could be improved.

Hereinafter, these will be sequentially described. (1) Dissolve in an atmosphere having an oxygen concentration of 15% or less.

The atmosphere having an oxygen concentration of 15% or less is achieved by supplying an inert gas, preferably nitrogen gas, to the melting apparatus. The heating temperature for dissolution is usually 100 to 2
00 ° C. is applied. Even when the hydrophobic compound is liquid at room temperature, it is preferable to heat to an emulsification temperature of 40 to 80 ° C.

As a result of investigations by the present inventors, the decomposition of a hydrophobic compound brought about when preparing an oil phase composition is more than that brought about by heating to a high temperature.
It has been found that it occurs due to the presence of oxygen. By setting the oxygen concentration to 15% or less, the influence of oxygen can be eliminated, and a stable dissolved substance can be provided even when dissolved at a high temperature. (2) Dissolve using a melt stabilizer.

In the present invention, the term "melt stabilizer" is a general term for additives to be added for the purpose of maintaining the stability of the hydrophobic compound of the present invention before and after dissolution. Is an additive with the desired function of

[0029] Therefore, the conventional anti-fading agents and high-boiling organic solvents used for silver halide photographic light-sensitive materials are different from the conventional ones in the purpose of addition even if the names and types of additives are the same. There is.

The heating temperature for dissolution is usually from 100 to
200 ° C. is applied. Even when the hydrophobic compound is liquid at room temperature, it is preferable to heat to an emulsification temperature of 40 to 80 ° C.

In the present invention, the melt stabilizer is preferably used in such an amount that the stability of the hydrophobic compound of the present invention before and after dissolution can be maintained. Usually, the preferred amount of the melt stabilizer is 0.01 to 0.01 in terms of the melt stabilizer / hydrophobic compound ratio.
-20, and a more preferred range is 0.01-.
It is 10.

In the present invention, compounds used as a melt stabilizer are exemplified below, but the melt stabilizer which can be used in the present invention is not limited thereto. . << Phenolic antioxidants >> Phenolic antioxidants are roughly classified into monophenol-based, polyphenol-based, polymer phenol-based, and hindered phenol-based, depending on their structure. <Monophenol compound> Examples of the monophenol compound include 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, and 2,6-di-t-.
Butyl-4-ethylphenol, stearyl-β-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate, 1-oxy-3-methyl-4-isopropylbenzene, 2,6-di-t-butyl-4-methylphenol, 2,6-di-t-butyl-4-sec-butylphenol, 2- (1 -Methylcyclohexyl)-
4,6-dimethylphenol, 2,6-t-butyl-α
-Dimethylamino-p-cresol, 2,6-di-t-
Examples include a mixture of butylphenol and 2,4,6-tri-t-butylphenol, a styrenated phenol, an alkylated phenol, and a mixture of alkyl and aralkyl-substituted phenols. <Polyphenol and high molecular phenol compounds> Examples of polyphenol and high molecular phenol compounds include 2,2'-methylenebis (4-methyl-6-t-butylphenol) and 2,2'-methylenebis (4-ethyl- 6-t-butylphenol), 4,4'-thiobis (3-methyl-6-t-butylphenol), 3,9-
Bis [1,1-dimethyl-2- [β (3-t-butyl-
4-hydroxy-5-methylphenyl) propionyloxy] ethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, 2,2-methylene-bis-
(4-methyl-6-cyclohexylphenol), 4,
4'-methylene-bis (2,6-di-t-butylphenol), 2,2'-methylene-bis (6-α-methyl-
Benzyl-p-cresol), methylene-bridged polyhydric alkylphenol, 4,4'-butylidene-bis (6-
t-butyl-m-cresol), 2,2'-ethylidene-bis (4,6-di-t-butylphenol), 1,1
-Bis (4-hydroxyphenyl) cyclohexane,
2,2'-dihydroxy-3,3'-di (α-methylcyclohexyl) -5,5'-dimethyl-diphenylmethane, alkylated bisphenol, butylated reactive product of p-cresol and dicyclopentadiene, polybutylated bisphenol A mixture of 1,3,5-trimethyl-
2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, 1,3,5-tris (4
-Tert-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, 2-tert-butyl-6- (3 '
-T-butyl-5'-methyl-2'-hydroxybenzyl) -4-methylphenyl acrylate, 2- [1-
(Hydroxy-3,5-di-tert-pentylphenyl) ethyl] -4,6-di-tert-pentylphenyl acrylate, 3,9-bis [2- {3- (3-tert-butyl-4-)
[Hydroxy-5-methylphenyl) propionyloxy {-1,1-dimethylethyl] -2,4,8,10-
Tetraoxyspiro [5,5] undecane, butyric acid-
3,3-bis (3-t-butyl-4-hydroxyphenyl) ethylene ester, 1,3,5-tri (2-hydroxyethyl) -s-triazine-2,4,6- (1H,
3H, 5H) trione 3,5, -di-t-butyl-4
-Hydroxyhydrocinnamic acid triesters, modified polyalkylphosphinated polyhydric phenols, and the like. <Hindered phenolic compound> Examples of the hindered phenolic compound include 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane and 4,4'-butylidenebis (3 -Methyl-6-t-
Butylphenol), 2,2-thiobis (4-methyl-
6-t-butylphenol), n-octadecyl-3-
(4'-hydroxy-3 ', 5'-di-tert-butylphenyl) propionate, tetrakis- [methylene-3-
(3 ', 5'-di-tert-butyl-4-hydroxyphenyl) propionate] methane, pentaerythritol-
Tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], triethyleneglycol-bis [3- (3-tert-butyl-tert-methyl-4-)
Hydroxyphenyl) propionate], 2,4-bis (n-octylthio) -6- (4-hydroxy-3,5
-Di-t-butylanilino) -1,3,5-triazine, tris- (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate, 2,2-thio-diethylenebis [3- (3 , 5-Di-tert-butyl-4-hydroxyphenyl) propionate], N, N'-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydroxynamamide), 2,4- Bis [(octylthio) methyl] -o-cresol, bis (3,5-di-
1: 1 mixture of calcium t-butyl-4-hydroxybenzylphosphonate) and polyethylene wax, 3,5-di-t-butyl-4-hydroxybenzylphosphonate-diethyl ester, tetrakis [methylene (3,5-diethyl -T-butyl-4-hydroxyhydrocinnamate)] methane, octadecyl-3- (3,5-
Di-t-butyl-4-hydroxyphenyl) propionic acid ester, hindered bisphenol and the like. << Phosphoric acid antioxidant >> Examples of the phosphoric acid antioxidant include the following. Triphenyl phosphite, diphenyl isodecyl phosphite, phenyl isodecyl phosphite, 4,4'-butylidene-bis (3-methyl-6-t-butylphenylditridecyl) phosphite, octadecyl phosphite, tris (nonylphenyl) ) Phosphite, tris (mono and / or dinonylphenyl) phosphite, diisodecylpentaerythritol diphosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene = 10-oxide, 10- (3,5 -Di-t-butyl-4-hydroxybenzyl) -9,10-dihydro-9-oxa-10-
Phosphaphenanthrene-10-oxide, 10-decyloxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene, tris (2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetrayl Bis (2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis (2,6-di-t-butyl-4-methylphenyl) phosphite, 2,2-methylenebis (4 6-di-t-butylphenyl) octyl phosphite, tetraphenyltetra (tridecyl) pentaerythritol tetraphosphite, 2,2'-ethylidenebis (4,6-di-t
-Butylphenol) fluorophosphite, 4,4 '
-Isopropylidene-diphenolalkyl (C12-
C15) phosphite, bis (nonylphenyl) pentaerythritol diphosphite, dibutyl hydrogen phosphite, distearyl pentaerythritol
Examples include diphosphite and phosphite compounds. << Sulfur-based antioxidant >> Examples of the sulfur-based antioxidant include the following compounds. Dilauryl thiodipropionate, distearyl thiodipropionate, dimyristyl-3,3'-thiodipropionate, ditridecyl-
3,3′-thiodipropionate, pentaerythritol-tetrakis (β-lauryl-thiopropionate), dilauryl thiodipropionate, β-alkylthioester propionate, sulfur-containing ester compound,
2-mercaptobenzimidazole, 2-mercaptomethyl-benzimidazole, a mixture of 2-mercaptobenzimidazole and a phenol condensate, a zinc salt of 2-mercaptobenzimidazole, a zinc salt of 2-mercaptomethylbenzimidazole, dioctadecyl sulfide, etc. No. << Amine-based antioxidant >> Examples of the amine-based antioxidant include the following. Phenyl-α-naphthylamine, phenyl-β-naphthylamine, p- (p-toluenesulfonylamide) diphenylamine, 4,4′-
(Α, α-dimethylbenzyl) diphenylamine, 4,
4'-dioctyl diphenylamine, a reaction product of diphenylamine with acetone, a reaction product of diphenylamine with aniline and acetone, octylated diphenylamine,
Dioctylated diphenylamine, p, p'-dioctyl-diphenylamine, N, N'-diphenyl-p-phenylenediamine, N-isopropyl-N'-phenyl-
p-phenylenediamine, N, N'-di-2-naphthyl-p-phenylenediamine, N-cyclohexyl-N '
-Phenyl-p-phenylenediamine, N-phenyl-
N '-(3-methacryloyloxy-2-hydroxypropyl) -p-phenylenediamine, N, N'-bis (1-methylheptyl) -p-phenylenediamine,
N, N'-bis (1,4-dimethylpentyl) -p-phenylenediamine, N, N'-bis (1-ethyl-3-
Methylpentyl) -p-phenylenediamine, N-
(1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine and the like. << Hydroquinone Derivatives >> As hydroquinone derivatives,
Examples thereof include 2,5-di- (t-amyl) hydroquinone, 2,5-di-t-butylhydroquinone, and hydroquinone monomethyl ether. << Higher alcohol >> Higher alcohol refers to a chain alcohol having 6 or more carbon atoms. Specifically, hexyl alcohol, octyl alcohol, dodecanol, octadecanol, cetyl alcohol, stearyl alcohol, oleyl alcohol, ceryl alcohol, lauryl alcohol, myristyl alcohol, behen alcohol, modified products thereof, and mixtures thereof. Can be << fatty acid esters >> fatty acid esters are a general term for ester compounds generated from fatty acids and alcohols,
As the acid side of the fatty acid ester, saturated fatty acids such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid,
Enanthic acid, caprylic acid, berargonic acid, capric acid,
Unsaturated fatty acids such as undecylic acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachinic acid, behenic acid, lignoceric acid, serotinic acid, heptacosanoic acid, montanic acid, lacceric acid, etc. Acrylic acid, crotonic acid, isocrotonic acid, undecylenic acid, oleic acid, elaidic acid, setrenic acid, erucic acid, brassic acid,
Sorbic acid, linoleic acid, linolenic acid, arachidonic acid,
Puopiolic acid, stearic acid and the like.

As the alcohol side of the fatty acid ester, all alcohols having a chain hydrocarbon can be used, but the higher alcohols having 6 or more carbon atoms are more preferable.

Among these fatty acid esters, compounds preferably used in the present invention include ethyl myristate, propyl myristate, isoprooil myristate, myristyl myristate, 2-ethylhexyl myristate, ethyl palmitate, propyl palmitate. Isopropyl palmitate, 2-ethylhexyl palmitate, ethyl stearate, propyl stearate, isopropyl stearate, stearic acid-2-
Examples include ethylhexyl, myristyl stearate, ethyl oleate, propyl oleate, isopropyl oleate, 2-ethylhexyl oleate, oleyl oleate, and mixtures thereof. (3) The hydrophobic compound used has an average particle size of 300 μm
Dissolve using the following powder:

The hydrophobic compound used has an average particle size of 300 μm.
By using the following powder, a stable melt can be produced. The use of a hydrophobic compound powder having an average particle diameter of 300 μm or less can provide a stable solution, but the reason has not been elucidated, but the specific surface area decreases as the particle diameter of the hydrophobic compound powder decreases. It is presumed that when the particle size becomes large and the average particle size becomes 300 μm or less, it is possible to dissolve in a relatively low temperature and in a short time as compared with the related art when dissolving without an auxiliary solvent.

The average particle diameter of the hydrophobic compound powder is 10
The thickness is more preferably 0 μm or less, and most preferably 50 μm or less.

Here, the particle diameter of the powder refers to the diameter when the powder is spherical or similar, and refers to the major axis diameter when the powder is acicular or similar. The average particle diameter can be measured by measuring the particle diameter of, for example, 100 powders in a certain visual field with an optical microscope and calculating the average value. In addition,
The coefficient of variation of the powder particle diameter is preferably low, specifically, preferably 20% or less. The powder of the hydrophobic compound of the present invention can be dissolved as it is if the average particle diameter of the powder generated through the synthesis process is already 300 μm or less, and if the average particle diameter exceeds 300 μm, It is possible to dissolve by pulverizing finely until a desired average particle size is obtained. As a method of finely pulverizing the powder, it is possible to use various known methods,
For example, a method using a mortar, a method using a known medium disperser, and the like can be mentioned.

The heating temperature for dissolution is usually from 100 to
200 ° C. is applied.

The lysate according to the present invention is characterized by being substantially free of an auxiliary solvent before and after dissolution of the hydrophobic compound.

In the present invention, the term "substantially free of an auxiliary solvent" means that no auxiliary solvent is contained at all, and also that the oil phase solution contains up to 1.0% of an auxiliary solvent. I have.

The above co-solvents usually have a boiling point of about 3
An organic solvent at 0 to 150 ° C. is used. Examples of the auxiliary solvent include lower alkyl acetate (ethyl acetate, butyl acetate, etc.), ethyl propionate, secondary butyl alcohol, methyl isobutyl ketone, cyclohexanone, and the like. Since the auxiliary solvent is an unnecessary substance in the photographic light-sensitive material after emulsification and dispersion, it is removed by a degassing method, an ultrafiltration method or the like. The auxiliary solvent is used to assist the dissolution of the hydrophobic compound, but is preferably not used from an environmental and sanitary point of view.

In the present invention, the oil-in-water type emulsified dispersion is
The oil phase solution containing the photographic hydrophobic substance is maintained at a preferable temperature of 40 to 90 ° C. for emulsification, and an aqueous phase solution containing at least one emulsification aid and / or a water-soluble binder is added and stirred, and It can be obtained by forming a water-drop type emulsion, further continuing the addition of the aqueous phase solution, inverting the phase, and emulsifying to obtain an oil-in-water type emulsion. The aqueous phase solution is maintained at a preferred temperature of 40-90C for emulsification.
An aqueous phase solution may be further added to the obtained oil-in-water emulsion for stabilization and viscosity adjustment. The aqueous phase solution in this case may be so-called water that does not contain an emulsifying aid or a water-soluble binder.

As an emulsifying apparatus for obtaining a water-in-oil type emulsion and an oil-in-water type emulsion, a container equipped with a stirrer is preferable. The rotational peripheral speed of the stirrer is 1 to 30 m / sec.
Preferably, the speed is 3 to 10 m / sec.

The particle size of the oil-in-water emulsion can be determined by appropriately selecting the type and amount of the emulsifying aid and the water-soluble binder contained in the aqueous phase solution, and the timing and rate of addition of the aqueous phase solution. Alternatively, it is generally carried out by changing the operating conditions of the emulsifying apparatus. However, by changing (viscosity of the oil phase solution) / (viscosity of the aqueous phase solution) from 1 to 100,000, It has been discovered that an oil-in-water emulsion having good stability over time and a small particle size can be obtained.
The more preferable viscosity ratio of the oil phase solution to the viscosity of the aqueous phase solution is 2 or more and 10,000 or less, and the viscosity of the aqueous phase solution is more than 300.
A preferable result is obtained when it is set to 0 cp or less. When the water-in-oil type emulsion is converted into an oil-in-water type emulsion, the addition of the aqueous phase solution is interrupted, and the mixture is stirred and dispersed for 1 minute or more, more preferably 5 minutes or more. It is also preferred to start adding the solution and stir to obtain an oil-in-water emulsion. It is currently unknown why the above gives a favorable result.

Whether phase inversion has occurred can be detected by measuring the viscosity or the conductivity of the emulsion. Phase inversion occurs when the viscosity of the emulsion becomes maximum or when the change in conductivity increases. In the study of the present inventor, the amount of aqueous phase solution added to the oil phase solution until phase inversion was substantially the same when phase inversion was detected by viscosity and when phase inversion was detected by conductivity. .

For the measurement of the viscosity, a vibrating viscometer or the like can be used, and for the measurement of the conductivity, an open-electrode conductivity meter or the like can be used. The viscosity meter and the conductivity meter may be installed in an emulsification container.

The viscosity of the oil phase solution changes depending on the mixing ratio of the hydrophobic compound used and the temperature. Therefore, the viscosity of the aqueous phase solution is adjusted according to the viscosity of the oil phase solution. The viscosity of the aqueous phase solution can be easily adjusted by the addition amount and temperature of the water-soluble binder and the emulsification aid. In addition, the viscosity here is a viscosity measured at the temperature at the time of emulsification, and is a value measured with a viscometer (RVDV-I) manufactured by Brookfield.

The composition of the aqueous phase solution to be added may be the same before and after the phase inversion, or may be different. Also,
Before the phase inversion, a plurality of aqueous phase solutions having different compositions may be sequentially added. Similarly, after the phase inversion, a plurality of aqueous phase solutions having different compositions may be sequentially added.

The particle size of the oil-in-water emulsion was measured using N4 manufactured by Coulter Corporation.

As the emulsifying aid used for forming the water-in-oil type emulsion, any emulsifying aid can be used. In the case of producing an oil-in-water type emulsion used for a photographic light-sensitive material, Include, for example, saponins (steroids), alkylene oxide derivatives (eg, polyethylene glycol, polyethylene glycol / polypropylene glycol condensate, polyethylene glycol alkyl ether, polyethylene glycol alkyl aryl ether, polyethylene glycol esters, polyethylene glycol sorbitan esters, Polyalkylene glycol alkylamines or amides, polyethylene oxide adducts of silicones), glycidol derivatives (eg, alkenyl succinic polyglycerides,
Alkylphenol polyglycerides), fatty acid esters of polyhydric alcohols, alkyl esters of sugars, and nonionic surfactants such as urethanes and ethers; Acid salt, alkyl naphthalene sulfonate, alkyl sulfate, alkyl phosphate, N-acyl-N
-Acidic groups such as carboxy group, sulfo group, phospho group, sulfate group, and phosphate group such as alkyl taurine, sulfosuccinate, sulfoalkyl polyoxyethylene alkyl phenyl ether and polyoxyethylene alkyl phosphate; Anionic surfactants such as amino acids, aminoalkyl sulfonic acids, aminoalkyl sulfates or phosphates, alkyl betaines, amine imides and amine oxides; alkyl amine salts, aliphatic or aromatic carboxylic acids Cationic surfactants such as quaternary ammonium salts, heterocyclic quaternary ammonium salts such as pyridinium and imidazolium, and phosphonium or sulfonium salts containing an aliphatic or heterocyclic ring can be used. Particularly preferred emulsifying aids are anionic surfactants.

The emulsifying aid may be previously contained in an oil phase solution comprising a hydrophobic compound.

As the water-soluble binder used for forming the water-in-oil type emulsion, any water-soluble binder can be used. For example, gelatin, gelatin derivatives, graft polymers of gelatin and other polymers, proteins such as albumin, casein; hydroxyethylcellulose, carboxymethylcellulose,
Cellulose derivatives such as cellulose sulfates, sugar derivatives such as sodium alginate, starch derivatives; polyvinyl alcohol, polyvinyl alcohol partial acetal, poly-N-vinylpyrrolidone, polyacrylic acid,
A synthetic hydrophilic polymer substance such as a homopolymer or a copolymer such as polymethacrylic acid, polyacrylamide, polyvinylimidazole, and polyvinylpyrazole can be used.

A silver halide photographic material using the oil-in-water emulsion dispersion of the present invention is described in, for example, JP-A-8-5
As described in JP-A Nos. 4716 and 4-151141, the oil-in-water type emulsified dispersion of the present invention is used as an oil-in-water emulsified dispersion to prepare the oil-in-water type emulsified dispersion by a method well known to those skilled in the art. be able to.

The light-sensitive material of the present invention can be obtained from Research Disclosures 17643, 18716 and 30811.
The development can be carried out by the usual method described in No. 9.

[0055]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. Example 1

<< Preparation of Melt 1 >> 1-color image forming agent
(2,4,6-trichlorophenyl) -3- [3-
(2,4-Di-t-amylphenoxyacetamide) benzamide] -5-pyrazolone (hydrophobic substance for photography)
(Hereinafter referred to as M-Cp) 6 kg and diisodecyl phthalate (high boiling point organic solvent) (hereinafter referred to as DIDP).
6 kg was placed in the same dissolving vessel, heated at 150 ° C. for 50 minutes to completely dissolve, and then cooled to 50 ° C. to prepare Dissolve 1. Melt 1 viscosity is 5000c
P. M-Cp was used as a powder having an average particle diameter of 500 μm.

<< Preparation of Dissolved Substances 2-5 >> In preparing the dissolved substance 1, a nitrogen gas was charged into the dissolving vessel, and the oxygen concentration of the dissolving vessel was adjusted to 16% (dissolved substance 2) and 14% (dissolved substance). 3) The lysates 2 to 5 were prepared by changing to 5% (lysate 4) and 1% (lysate 5). Melts 2-5 have a viscosity of 5
000 cP.

For each of the obtained melts 1 to 5,
The concentration of M-Cp before and after dissolution was measured using liquid chromatography (HPLC), and the residual ratio (%) of M-Cp after dissolution relative to before dissolution was determined. Survival rate is 10
A value closer to 0% indicates that the stability before and after dissolution is maintained. Table 1 shows the obtained results.

[0059]

[Table 1]

Example 2 << Preparation of Dissolved Materials 6-14 >> M-Cp 6 kg, DIDP
6 kg and 2 kg of the melt stabilizer shown in Table 2 were placed in the same dissolving vessel, heated at 150 ° C. for 50 minutes to dissolve, and then cooled to 50 ° C. to prepare Dissolved products 6 to 14. Melt 1 had a viscosity of 4500 cP. Also,
M-Cp was used as a powder having an average particle size of 500 μm.

For each of the obtained lysates 6 to 14, the concentration of M-Cp before and after dissolution was measured by liquid chromatography (HPLC), and the residual ratio of M-Cp after dissolution to that before dissolution was measured. (%) Was determined. The closer the residual ratio is to 100%, the more the stability before and after dissolution is maintained. Table 2 shows the obtained results.

[0062]

[Table 2] Example 3

<< Preparation of Dissolved Materials 15 to 17 >> M-Cp was pulverized in a mortar, and the average particle size was 280 μm, 150 μm,
M-Cp with μm was made.

M-Cp 6 having the average particle size shown in Table 3
Kg and 6 Kg of DIDP in the same dissolution vessel,
Heat at 50 ° C. to completely dissolve. The time required for M-Cp to completely dissolve was determined by the M-Cp having an average particle size of 280 μm.
Of the melt 15 using M-Cp having an average particle size of 150 μm was 38 minutes, and the average particle size was 70 minutes.
Lysate 17 using μm M-Cp took 34 minutes. Thereafter, the mixture is cooled to 50 ° C.
7 was created.

For each of the obtained lysates 15 to 17, the concentration of M-Cp before and after dissolution was measured by liquid chromatography (HPLC), and the residual ratio of M-Cp after dissolution to that before dissolution was measured. (%) Was determined. The closer the residual ratio is to 100%, the more the stability before and after dissolution is maintained. Table 3 shows the obtained results.

[0066]

[Table 3] Example 4

<< Preparation of Emulsions 1-17 >> Each of the melts 1-17 obtained in Examples 1, 2 and 3 was added with 3% by weight of sodium dodecylbenzenesulfonate and 20% by weight of gelatin.
Aqueous solution (50 ° C.) adjusted to a viscosity of 2000 cp by adding polystyrene sulfonic acid to an aqueous solution containing is added with stirring, first, a water-in-oil type emulsion is prepared, and To the oil-in-water emulsion (emulsion 1
To 17). A total of 18 L of the aqueous phase solution was added. The addition time required 20 minutes. The stirring was performed at a peripheral speed of 4
m / sec.

The average particle size of the obtained oil-in-water emulsions was all in the range of 180 to 190 nm. Further, the variation coefficients were all within the range of 15 to 18%.

These oil-in-water emulsions were stored at 5 ° C. for one month, and the residual ratio of M-Cp was determined by liquid chromatography (HPLC) in the same manner as in Example 1. Table 4 shows the obtained results.

[0070]

[Table 4]

[0071] Example 5 transparent cellulose triacetate based on, applying the emulsion to 17 immediately after creation prepared in Example 4, respectively, dried, to observe the coated surface with a loupe (20 ×), 1 m ² per The number of pinholes was determined. Further, the number of pinholes per 1 m ² was obtained in the same manner as described above using Emulsions 1 to 17 in which each of the emulsions was stored at 60 ° C. for 24 hours.

Each of the melts 1 to 17 obtained in Examples 1, 2 and 3 was stirred in an aqueous phase solution (50 ° C.) consisting of 6 kg of gelatin, 3 L of 10% sodium dodecylbenzenesulfonate and 56 L of water. While adding oil-in-water emulsions (emulsions 18 to 34). The stirring was performed at a peripheral speed of 20 m / sec for 30 minutes.

The average particle size of the obtained oil-in-water emulsion was in the range of 250 to 260 nm. Further, the coefficient of variation was in the range of 35 to 40%.

[0074] The resulting emulsion was 18 to 34, in the same manner as above to determine the number of pinholes of 1 m ² per post number and time saving pinholes per 1 m ² of the emulsion immediately after creation.

Table 5 shows the obtained results.

[0076]

[Table 5]

Example 6 (Evaluation of photosensitive material) Silver halide emulsion: A core / shell type silver iodobromide having an average particle diameter of 0.38 μm was prepared by a double jet method, desalted by a conventional method, and then thiosulfuric acid. Chemical ripening was performed using sodium and chloroauric acid to obtain optimum sensitivity.
Sensitizing dyes I and II were added to the sol-form emulsion at 5 × 10 ⁻⁴ mol and 1 × 10 ⁻⁴ mol per mol of silver of the emulsion, and the mixture was spectrally sensitized to green light sensitivity.

Further, emulsions 1 to 34 were added to the emulsion, and the coupler (M-Cp) was 0.1 to 0.1 g / g of silver contained in the emulsion.
It was added so as to be 5 g. Further, the following additives were added and applied to polyethylene laminated paper to prepare a coated sample. (Photosensitive Materials 1-34) The gelatin amount was 1 g / m ^2, and a gelatin protective layer having a dry film thickness of 1 μm was coated on the coated sample.

Additives Thickener V-1 A 4% solution is added to a viscosity of 32 cp. Coating aid 1.2 cc of a 1% solution of Su-2 is added to 200 cc of the emulsion.

[0080]

Embedded image The obtained photosensitive material was subjected to wedge exposure using green light using a sensitometer KS-7 (manufactured by Konica Corporation). Next, development processing was performed in the following processing steps, and the reflection density was measured using a PDA-65 densitometer (manufactured by Konica Corporation) to determine the maximum color density (Dmax). After storing the developed photosensitive materials 1 to 34 in an atmosphere at 85 ° C. and a relative humidity of 60% for one week, the reflection density was measured again to obtain the maximum color density (D′ max), and the following formula was used. The maximum color density reduction rate (%) was determined.

[0081]

(Equation 1) The lower the maximum color density reduction rate, the more stable the image is. Table 6 shows the obtained results.

Processing Step Temperature Time Replenishment amount Color development 35.0 ± 0.3 ° C. 45 seconds 120 ml Bleaching and fixing 35.0 ± 0.3 ° C. 45 seconds 51 ml Stability 30-34 ° C. 90 seconds 250 ml (3 cascades) Dry Drying 60 to 80 ° C for 30 seconds The composition of the treatment liquid is shown below.

Color developing solution Tank liquid Pure water 800 ml Triethanolamine 10 g N, N-diethylhydroxylamine 5 g Potassium chloride 2 g 1-hydroxyethylidene-1,1-diphosphonic acid 1 g 1-ethyl-N-β-methanesulfonamidoethyl -3-Methyl-4-aminoaniline sulfate 5.4 g Potassium carbonate 27 g Add water to make 1 L, adjust pH with potassium hydroxide or sulfuric acid.
To 10.10.

Replenisher Pure water 800 ml Triethanolamine 18 g N, N-diethylhydroxylamine 9 g 1-hydroxyethylidene-1,1-diphosphonic acid 1.8 g N-ethyl-N-β-methanesulfonamidoethyl-3-methyl -4-Aminoaniline sulfate 8.2 g Potassium carbonate 27 g Add water to make 1 L, adjust pH with potassium hydroxide or sulfuric acid.
Is adjusted to 10.60.

Bleach-fixing tank solution and replenisher solution Ferric ammonium ammonium salt of ethylenediaminetetraacetic acid 53 g Ethylenediaminetetraacetic acid 3.0 g Ammonium thiosulfate (70%) solution 123 g Ammonium sulfite (40%) solution 51 g Aqueous ammonia or glacial acetic acid at pH 5.4 And add water to bring the total volume to 1L.

Stabilizing tank solution and replenisher orthophenylphenol 0.1 g Juvittex (Ciba-Geigy) 1.0 g zinc sulfate-7-hydrate 0.1 g ammonium sulfite (40% solution) 5.0 ml 1-hydroxyethylidene- 1,1-Diphosphonic acid 3.0 g Ethylenediaminetetraacetic acid 1.5 g Adjust the pH to 7.8 with aqueous ammonia or glacial acetic acid, and add water to make the total volume 1 L.

[0087]

[Table 6]

Example 7 << Preparation of Emulsions 35 to 40 >> Polystyrene sulfonic acid was added to the solution 3 obtained in Example 1 to an aqueous solution containing 3% by weight of sodium dodecylbenzenesulfonate and 20% by weight of gelatin. Viscosity 2900
An aqueous phase solution (50 ° C.) adjusted to cP was added with stirring, first, a water-in-oil type emulsion was prepared, and the aqueous phase solution was further added to add an oil-in-water type emulsion (emulsion 35). )made. A total of 18 L of the aqueous phase solution was added. The addition time required 20 minutes.

Further, in the preparation of the above-mentioned emulsion 35, an aqueous phase solution excluding gelatin (having a viscosity of 5 c
Emulsion 3 was prepared in the same manner as in Emulsion 35 except that p) was used.
No. 6 was created.

Next, emulsions 35 and 36 were prepared except that melts 7 and 15 obtained in Examples 2 and 3 were used instead of melt 3 in the preparation of emulsions 35 and 36. In the same manner as in the above, emulsions 37 to 40 were prepared.

The average particle size of the obtained emulsions 35 to 40 is 1
In the range of 80 to 190 nm, and the coefficient of variation is 15
１８18%.

[0092]

Thus, according to the method for dissolving an oil phase solution containing a photographic hydrophobic substance of the present invention, an oil phase solution containing a photographic hydrophobic substance having an improved stability of the photographic hydrophobic substance is obtained. According to the method for emulsifying and dispersing a photographic hydrophobic substance of the present invention, an oil-in-water emulsion having improved stability over time of the dispersion can be obtained, and the silver halide photograph of the present invention can be obtained. The light-sensitive material has improved image storability.

Claims (9)

[Claims] An oil phase solution component containing at least one photographic hydrophobic substance and containing substantially no auxiliary solvent is dissolved in an atmosphere having an oxygen concentration of 15% or less. A method for dissolving an oil phase solution containing a hydrophobic substance. 2. An oil phase solution component containing at least one photographic hydrophobic substance and substantially free of a cosolvent is dissolved in the presence of at least one melt stabilizer. A method for dissolving an oil phase solution containing a photographic hydrophobic substance. 3. The method according to claim 1, wherein the melt stabilizer is a phenolic antioxidant,
The melt stabilizer according to claim 2, wherein the stabilizer is a phosphoric acid antioxidant, a sulfur antioxidant, an amine antioxidant, a hydroquinone derivative, a higher alcohol or a fatty acid ester. A method for dissolving an oil phase solution containing a photographic hydrophobic substance. 4. A photographic hydrophobic substance comprising at least one photographic hydrophobic substance having an average particle diameter of 300 μm or less and dissolving an oil phase solution component substantially free of an auxiliary solvent. A method for dissolving an oil phase solution comprising: 5. An aqueous phase solution containing at least one emulsifying aid and / or a water-soluble binder is added to an oil phase solution containing at least one photographic hydrophobic substance and substantially free of an auxiliary solvent. A water-in-oil type emulsion is formed, and the addition of an aqueous phase solution is further continued to invert the phase to produce an oil-in-water type emulsion, wherein the oil phase solution has an oxygen concentration of 15% A method for emulsifying and dispersing a photographic hydrophobic substance, which is obtained by being dissolved in the following atmosphere. 6. An aqueous phase solution containing at least one emulsifying aid and / or a water-soluble binder is added to an oil phase solution containing at least one photographic hydrophobic substance and substantially free of an auxiliary solvent. Stirring to form a water-in-oil emulsion, further adding an aqueous phase solution, and inverting the phase to produce an oil-in-water emulsion, wherein the oil phase solution comprises at least one kind of oil-in-water emulsion. A method for emulsifying and dispersing a photographic hydrophobic substance, comprising a melt stabilizer. 7. A phenolic antioxidant, wherein the melt stabilizer comprises:
7. A melt stabilizer selected from a phosphoric acid antioxidant, a sulfur antioxidant, an amine antioxidant, a hydroquinone derivative, a higher alcohol or a fatty acid ester, according to claim 6, wherein A method for emulsifying and dispersing a photographic hydrophobic substance. 8. An aqueous phase solution containing at least one emulsifying aid and / or a water-soluble binder is added to an oil phase solution containing at least one photographic hydrophobic substance and containing substantially no co-solvent. Stirring, forming a water-in-oil emulsion, further adding an aqueous phase solution and inverting the phase to produce an oil-in-water emulsion, wherein the oil phase solution has an average particle size of 300 μm A method for emulsifying and dispersing a photographic hydrophobic substance, characterized by being formed by heating and melting using the following photographic hydrophobic substance powder. 9. An oil-in-water emulsion of a photographic hydrophobic substance formed by the method of emulsifying and dispersing a photographic hydrophobic substance according to any one of claims 5 to 8. Silver halide photographic material.