JPH06250320A - Silver halide photographic sensitive material - Google Patents

Abstract

PURPOSE:To obtain a photographic element having high sensitivity with little deterioration of film properties by using a latex having isoprene sulfonic acid monomer unit into an emulsion containing platelike particles. CONSTITUTION:This photographic element consists of at least a supporting body and silver halide gelatin emulsion layers. At least one layer of the photographic element contains plate-like particles with <=3 aspect ratio and a latex consisting of polymers having at least isoprene sulfonic acid monomer unit. The isoprene sulfonic acid monomer is expressed by a formula CH2=C(CH3)-C (SO3M)=CH2. In the formula, M is hydrogen atom, an alkali metal such as sodium and potassium, or ammonium, and can be polymerized in an acid or salt form. The latex used has such features that it gives no adverse influence or very little influence even when used in a silver halide photographic element.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel silver halide photographic element, and more particularly to a silver halide photographic element having high sensitivity, low fog and improved film physical properties.

[0002]

2. Description of the Related Art Tabular silver halide grains are often used in silver halide photographic light-sensitive materials containing gelatin as a binder. This is because flattening increases the projected area, increases the amount of light received per unit grain, and allows a large amount of sensitizing dyes to be adsorbed, and higher spectral sensitization is expected.

On the other hand, with the progress of electronics, the shortening of the access time to images has been drastically advanced, and silver halide photographic light-sensitive materials are required to be processed more and more rapidly.

Therefore, there is a demand for a technique for reducing the amount of gelatin used as a binder that has protected silver halide grains and shortening the photographic processing such as developing speed, fixing speed, water washing speed, and drying speed. . When the amount of gelatin used is reduced, the silver halide grains with high sensitivity become more and more weak against external pressure, and attempts have been made to improve the grain preparation method to overcome this, but high sensitivity and low fog have been tried. At the same time, no silver halide grains having both high pressure resistance have been found yet.

To this end, it has often been the case to add latices that are soft and function as buffers.
However, latex has various adverse effects on the silver halide grains, which are the photoreceptor, and also deteriorates the physical properties of the photographic element film, making it easier to scratch and using it because it deteriorates the scratches between the films during storage. However, it was not possible to achieve the purpose sufficiently.

To solve this problem, the present invention can provide a photographic element having high sensitivity and little deterioration of film properties by using a latex having an isoprenesulfonic acid monomer unit in an emulsion containing tabular grains.

[0007]

SUMMARY OF THE INVENTION In response to the above problems, an object of the present invention is to provide a novel photographic element using silver halide grains having high sensitivity and low fog. Another object of the present invention is to improve the film physical properties of photographic elements. More specifically, it is to provide a photographic element having high sensitivity, excellent pressure resistance and scratch resistance, and free from scratches.

Other objects of the invention will be apparent in the following detailed description.

[0009]

The above object of the present invention is a photographic element comprising a support and at least a silver halide gelatin emulsion layer, in which at least one tabular grain of the photographic element has an aspect ratio of 3 or more. And a latex comprising a polymer having at least isoprene sulfonic acid monomer units.

The present invention will be specifically described below.

First, a latex made of a polymer having an isoprenesulfonic acid monomer unit used in the present invention will be described.

The isoprene sulfonic acid monomer has the general formula
CH ₂ = C (CH ₃ ) -C (SO ₃ M) = CH ₂ , M represents a hydrogen atom or an alkali metal such as sodium or potassium or ammonium, and can be polymerized in the form of an acid or a salt. . The molecular weight of the copolymerization product can be set from 1,000 to 1,000,000 depending on the degree of polymerization. Preferred molecular weight is 15
It is from 00 to 600,000 but is not limited to this molecular weight.

The particle size of the latex can be arbitrarily selected from 0.001 to 10 μm. If the particle size is large, the haze of the film deteriorates. On the other hand, if it is small, a large amount of emulsifier is required, which deteriorates photographic performance and film physical properties. The preferable particle diameter is 0.01 to 1 μm, and the narrower the particle diameter distribution is, the more preferable. The index showing the distribution of grains can be expressed by a statistical coefficient of variation, as in the case of silver halide grains. Usually used within 40%. It is preferably within 30%, more preferably within 20%, within 10%, and within 5%. The method of narrowing the distribution may be to eliminate the heterogeneity of the polymerization reaction. For example, it is possible to satisfactorily stir the reaction vessel (stirring under Reynolds' complete stirring and mixing conditions), control addition of monomers (flow rate control, pH control), and the like.

Specific examples of the latex of the present invention are shown below. Here, isoprene sulfonic acid is IPS and styrene is
St, α-methylenesulfonic acid α-mSt, methyl acrylate MA, methyl methacrylate MMA, ethyl acrylate EA, butyl acrylate BA, hexyl acrylate HA, isononyl acrylate INA, cyclohexyl methacrylate CA, hydroxyethyl Acrylate HEA, hydroxyethyl methacrylate HEMA,
Acrylic acid is AA, itaconic acid is IA, maleic acid is MA, acrylamide AAm, styrenesulfonic acid is StS, acrylamido-2-methylpropanesulfonic acid amide is AMPS, 2-
Propenyl-4-nonylphenoxyethylene oxide (n =
10) Sulfonic acid ester is abbreviated as PFS. The attached small letters represent the composition weight composition ratio.

Specific Example of Latex Monomer Species Molecular Weight (10,000) Average Particle Size Coefficient of Variation (%) (1) St ₂₅ MA ₂₅ EA ₄₀ IPS ₁₀ 2 0.20 13 (2) St ₃₅ MA ₁₅ EA ₄₀ IPS ₁₀ 1 0.20 12 ( 3) St ₃₅ MA ₁₅ EA ₄₀ IPS ₁₀ 2 0.20 13 (4) [(2) activator change] 2 0.20 10 (5) St ₂ CA ₅₀ NA ₃₈ IPS ₁₀ 2 0.20 12 (6) St ₄₀ MMA ₁₀ EA ₄₀ IPS ₁₀ 2 0.20 12 (7) St ₂ MMA ₁₀ NA ₄₀ IPS ₁₀ 3 0.10 13 (8) AN ₂₅ MMA ₁₀ EA ₄₀ IPS ₁₀ 3 0.10 12 (9) α-m St ₂₈ MMA ₁₀ EA4 _0I PS ₈ 2 0.20 13 (10) St ₂₀ MMA ₃₀ EA ₄₀ BA ₈ IPS ₂ 2 0.20 21 (11) St ₁₀ MMA ₃₀ EA ₅₀ IPS ₁₀ 2 0.20 15 (12) EA ₉₀ IPS ₁₀ 5 0.10 8 (13) MMA ₁₀ EA ₈₈ IPS ₂ 0.2 0.10 13 (14) St ₃₀ MMA ₂₀ EA ₄₀ BA ₅ IPS ₅ 0.8 0.20 12 (15) CA ₆₀ INA ₃₀ IPS ₁₀ 3 0.10 13 (16) MMA ₅₀ EA ₄₀ IPS ₁₀ 4 0.10 10 (17) MMA ₅₀ EA ₄₀ IPS ₁₀ 10 0.10 12 (18) EA ₉₀ IPS ₁₀ 50 0.10 12 (19) MMA ₅₀ EA ₄₀ IPS ₁₀ 20 0.10 13 (20) St ₂₀ MMA ₃₀ EA ₅₀ IPS ₁₀ 10 0.20 12 (21) St ₁₀ MMA ₃₀ EA ₅₀ HEMA ₅ IPS ₅ 10 0.20 13 (22) BA ₄₀ St ₂₀ EA ₃₀ AA ₅ IPS ₅ 10 0.10 21 (23) CA ₆₀ INA ₃₀ MA ₁₀ IPS ₂ 2 0 0.10 15 (24) CA ₆₀ INA ₃₀ AMPS ₈ IPS ₂ 4 0.10 8 (25) CA ₅₀ INA ₃₀ EA ₁₀ IPS ₁₀ 3 0.08 8 (26) EA ₉₅ AA3 ₃ IPS ₂ 10 0.06 13 (27) EA ₉₁ BA ₃ IPS ₆ 13 0.05 12 (28) EA ₄₂ BA ₄₇ AA ₃ IPS ₈ 20 0.03 13 (29) EA ₈₀ MMA ₅ IPS ₁₅ 2 0.02 10 (30) St ₂₀ MMA ₂₉ EA ₃₉ BA ₈ AA ₃ IPS ₁ 5 0.01 12 ( 31) St ₁₅ IPS ₅ MMA ₃₀ EA ₅₀ 0.2 0.20 12 (32) EA ₆₅ IPS ₃₅ 0.8 0.05 13 (33) MMA ₂ EA ₈₈ AMPS ₁₀ IPS ₃ 3 0.06 12 (34) St ₃₂ MMA ₂₀ EA ₄₀ BA ₅ AA ₃ IPS ₃ 4 0.30 13 (35) CA ₅₀ INA ₃₀ IPS ₂₀ 10 0.15 21 The latex used in the present invention is characterized by having no or very little adverse effect on the following points when used in a silver halide photographic element. is there. The latex surface is photographically inert and has very little interaction with various photographic additives. As an example, dyes and pigments are less likely to be adsorbed to color stain photographic elements. Further, it is difficult to adsorb a development accelerator, a development inhibitor or the like which has an influence on the development speed, and it is difficult to affect the sensitivity and the fog. Further, when a photographic element is produced, the pH dependence of the photographic solution in which the latex of the present invention is dispersed is small and it is not easily influenced by the ionic strength, so that it does not easily aggregate and precipitate.

The fact that the latex of the present invention has the above-mentioned properties is considered to be greatly influenced by the monomer composition and properties of this latex.

An index called a glass transition point is often used for latex. The higher this transition point, the harder it is,
Although it cannot serve as a buffer, if it is too low, it is likely to interact with photographic performance and adversely affect it. Therefore, the selection of the composition and the amount used are not simple considering the photographic characteristics. Latex using monomers such as styrene, methyl methacrylate and ethyl acrylate is well known, but none of them gave satisfactory performance. In addition, it is said that introduction of a monomer having a carboxylic acid group such as acrylic acid, itaconic acid, maleic acid or the like during the synthesis of a latex reduces the influence on photographic properties, and such a synthesis is often attempted. However, such a method also does not guarantee good performance. It was unexpected that the present invention exerted a surprising effect on the latex obtained by such a combination by including at least isoprenesulfonic acid monomer units. The isoprene sulfonic acid monomer is one in which a sulfonic acid group is introduced into the isoprene skeleton, and can be easily synthesized and obtained.

The amount of isoprenesulfonic acid units introduced into the latex is preferably 0.01 or more and 30% by weight or less based on the latex solid content. The latex synthesis method is, for example,
It can be synthesized by the method described in 60-15935. The latex synthesis method is not limited because there are numerous synthesis methods other than this patent. It is preferable to select an alkyl acrylate, an alkyl methacrylate, or a styrene-based monomer as a monomer used when synthesizing the latex. As the alkyl group of alkyl acrylate or alkyl methacrylate, methyl group, ethyl group,
Cyclic saturated ring such as butyl group, hexyl group, octyl group, nonyl group, dodecyl group, hexadecyl group, etc., which may be substituted, straight chain or branched aliphatic group or cyclohexyl group, and phenyl group , Those having an aromatic group such as a pyridyl group and a furan group directly substituted, and those having a linking group therebetween. Special public relations for selecting monomers
It is possible to select from the exemplified monomers described in 60-15935. The blending of these monomers is preferably selected as appropriate by setting the glass transition point which is an index of the hardness of the latex. The glass transition point of the latex is greatly affected by the selection of the alkyl group, but it is preferable to set the glass transition point to 60 ° C. or lower by selecting 20% by weight or more of the alkyl acrylate component, and particularly 50
C. or lower, more preferably 40.degree. C. or lower. The latex of the present invention contains an isoprenesulfonic acid monomer unit, but it is not always necessary to copolymerize all of them in the latex. This is because it is considered that a part of the polymerization proceeds as a homopolymer and acts as a dispersion medium when the latex is generated to stabilize the polymerization.
Therefore, it is also possible to polymerize the isoprenesulfonic acid monomer in advance and polymerize the other monomer in this homopolymer.

The stability of the latex can be imparted by using a surfactant for dispersing the monomer during the latex synthesis. The type of activator can be arbitrarily selected from anionic, nonionic, cationic and amphoteric. Nonionic or anionic activators, alone or in combination, give good results.

As the dispersion medium for the latex, natural amphoteric gelatin may be used. When gelatin is used, it can be incorporated into a latex to obtain a latex having good crosslinkability. There are two methods of using gelatin: one is to add gelatin instead of the active agent, and the other is to use it in combination with the active agent. The gelatin may be either one obtained by alkali decomposition or one treated with an acid. Further, the molecular weight can be controlled depending on the degree of decomposition so that the dispersibility of the monomer can be improved and it can be used.

Photographic elements using the latex of this invention include:
It can also be used for medical applications, printing and color sensitive materials.
Here, an example of the X-ray sensitive material is given, but it is not limited to this.

High-sensitivity tabular grains are used as the silver halide used in the photographic element of the present invention. AgBr, AgCl, AgClBr, AgClBrI, AgBrI, AgCl are used as the silver halide composition.
BrB can be used as desired, but AgB is rich in AgBr composition
rI is preferred.

Tabular grains are described in US Pat. No. 4,439,520,
No. 4,425,425, No. 4,414,304, etc.,
Target tabular grains can be easily obtained. The tabular grains can be formed by epitaxially growing silver halide having a different composition on a specific surface site or by shelling. Further, in order to control the photosensitive nuclei, a transition line may be provided on the surface or inside of the tabular grains.

The tabular grains of the present invention are preferably tabular grains having an aspect ratio of 3 or more in 50% or more of the total projected area of all grains in the emulsion layer in which the tabular grains are used. Especially tabular grains account for 60% to 70% and 80%
The better the result, the better the result. The aspect ratio here means the ratio of the diameter of a circle having the same area as the projected area of tabular grains and the distance between two parallel planes. In the present invention, the aspect ratio is preferably 3 or more and less than 20, more preferably 3 or more and less than 16.

The tabular grains of the present invention preferably have a thickness of 0.5 μm or less, preferably 0.3 μm or less. Also, the tabular grain distribution is often used as a coefficient of variation.
A monodisperse emulsion having a (standard deviation S when the projected area is approximated to a circle approximated by 100 times the value S / D obtained by dividing by the diameter D) is 30% or less, particularly 20% or less is preferable. Further, two or more kinds of tabular grains and non-tabular grains of normal crystal may be mixed.

Ammonia, thioether compounds, thione compounds and the like can be used as a silver halide solvent in order to control grain growth during formation of tabular grains. Further, metal circles such as zinc, lead, thallium, iridium, and rhodium can coexist during physical aging and chemical aging.

The above silver halide can be sensitized with a noble metal salt such as a sulfur compound or a gold salt. Further, reduction sensitization can be performed, and these methods can be combined for sensitization.

The photographic element of the present invention can be obtained by coating an emulsion prepared by dispersing the above silver halide in a hydrophilic colloid medium, for example, gelatin into a polyethylene terephthalate or triacetate cellulose support.

For cross-linking gelatin, an aldehyde such as glyoxal or mucochloric acid, cyanuric acid, aziridine or vinyl sulfonic acid can be used.

Other compounds such as an antihalation dye, a safelight improving dye, a sensitizing dye, a fog inhibitor, a matting agent, an antistatic agent and a development modifier which can be contained in the photographic element of the present invention are selected according to the use and performance. It can be selected appropriately.

[0031]

EXAMPLES The effects of the present invention will be illustrated by the following examples.

[Comparison of Comparative Latex (a)]
Ethyl acrylate: AM according to Example 1 of 60-15935
97: 3% by weight of PS was synthesized.

[Synthesis of Comparative Latex (b)] According to comparative latex (a), methyl methacrylate: methyl methacrylate (60: 40% by weight) was synthesized.

[Synthesis of Comparative Latex (c)] A latex of styrene: butyl acrylate: acrylic acid 60: 39: 1% by weight was synthesized according to the comparative latex (b).

[Synthesis of Latex (1) of the Present Invention] Latex (1) of the present invention was synthesized according to comparative latex (a).

However, 25% by weight of styrene as a monomer:
A latex containing 25% by weight of methyl acrylate, 30% by weight of ethyl acrylate and 10% by weight of isoprenesulfonic acid and having a solid content of 20% was synthesized. As an activator, 0.2 g of C ₁₂ H ₂₅ C ₆ H ₅ SO ₃ Na was used as the total solid content.

[Synthesis of Latex (2) of the Present Invention] Latex (2) of the present invention according to Latex (1) of the present invention
Was synthesized.

However, 35% by weight of styrene as a monomer:
A latex containing 15% by weight of methyl acrylate, 40% by weight of ethyl acrylate and 10% by weight of isoprenesulfonic acid and having a solid content of 15% was synthesized. Further, C ₁₂ H ₂₅ OSO ₃ Na was used as an activator in an amount of O.2% by weight of the total solid content.

[Synthesis of Latex (3) of the Present Invention] Latex (3) of the present invention according to Latex (2) of the present invention
Was synthesized.

However, 35% by weight of styrene as a monomer:
A latex containing 15% by weight of methyl acrylate, 40% by weight of ethyl acrylate and 10% by weight of isoprenesulfonic acid and having a solid content of 15% was synthesized. The solid content concentration adjusted the initial water content and the final water content. As an activator, C ₁₂ H ₂₅ OSO ₃
Na was used at 0.3% by weight of the total solid content.

[Synthesis of Latex (4) of the Present Invention] Latex (4) of the present invention according to Latex (3) of the present invention
Was synthesized.

However, 2% by weight of styrene as a monomer:
A latex containing 50% by weight of cyclohexyl methacrylate, 38% by weight of nonyl acrylate and 10% by weight of isoprenesulfonic acid and having a solid content of 15% was synthesized. The solid content concentration adjusted the initial water content and the final water content. Also activator C
₁₂ H ₂₅ OSO ₃ Na was used at 0.3% by weight of the total solid content.

[Synthesis of Latex (5) of the Present Invention] Latex (5) of the present invention according to Latex (4) of the present invention
Was synthesized.

However, 40% by weight of styrene as a monomer:
Methyl methacrylate 10% by weight Ethyl acrylate 4
0% by weight, isoprenesulfonic acid 10% by weight, solid content 15%
Of latex was synthesized. C ₁₂ H ₂₅ OSO as an activator
0.1% by weight of total solids of ₃ Na was used.

[Synthesis of Latex (6) of the Present Invention] Latex (6) of the present invention according to Latex (5) of the present invention
Was synthesized.

However, 2% by weight of styrene as a monomer:
Methyl methacrylate 10% by weight: Nonyl acrylate 40
A latex having a solid content of 15% by weight and 10% by weight of isoprenesulfonic acid was synthesized. As an activator, C ₁₂ H ₂₅ OSO ₃ Na
Was used at 1.0% by weight of the total solid content and alkali potassium treated gelatin. Gelatin was dissolved in 10% by weight of pure water that had been ion-exchanged in advance.

[Synthesis of Latex (7) of the Present Invention] The latex (7) of the present invention was synthesized according to the latex (6) of the present invention.

However, as the monomer, acrylonitrile 25
% By weight: 10% by weight of methyl methacrylate 40% by weight of ethyl acrylate, 10% by weight of isoprenesulfonic acid, and a latex having a solid content of 15% was synthesized. C ₁₂ H as an activator
₂₅ OSO ₃ Na was used at 1.0% by weight of total solids and alkali treated gelatin. Gelatin was dissolved in 5% by weight of pure water that had been ion-exchanged in advance.

[Synthesis of Latex (8) of the Present Invention] Latex (8) of the present invention according to Latex (7) of the present invention
Was synthesized.

However, as the monomer, α-methylstyrene 2
8% by weight: 10% by weight of methyl methacrylate 40% by weight of ethyl acrylate, 8% by weight of isoprene sulfonic acid A latex having a solid content of 15% was synthesized. Also as an activator
1.0% by weight of C ₁₂ H ₂₅ OSO ₃ Na and alkali-treated gelatin were used. Gelatin was dissolved in 5% by weight of pure water that had been ion-exchanged in advance.

(Preparation of photographic light-sensitive material) Using the tabular grains and the latex of the present invention, an ortho-light-sensitive material for X ray was prepared and evaluated for photographic performance and physical properties. The creation of photosensitive material
It was based on the example of JP-A-63-305343. The emulsion was subjected to gold-sulfur sensitization and spectrally sensitized with 5,5'-dichloro-9-ethyl-3,3-bis (3-sulfopropyl) -oxacarbocyanine sodium salt as an orthocyanin dye. However, the amount of the sensitizing dye was changed as follows according to the aspect ratio of the emulsion. The amount added is expressed in mg per mol of silver.

[0052] Further, the latex shown in Table 1 was added so that the amount would be 1.3 g / m ² .

This emulsion was coated on both sides of a 175 μm thick polyethylene terephthalate support colored in blue to prepare samples No. 1 to No. 20 as shown in Table 1.

[0054]

[Table 1]

The following methods were used to evaluate these samples.

Sensitometry After exposure with green light for 0.1 second, development, fixing, washing with water and drying treatment were carried out with a developer having the following composition. Sensitivity is fog +
It is expressed as the reciprocal of the exposure dose that gives a density of 1.0.

Evaluation of pressure resistance After a test piece having a width of 3.5 cm and a length of 12.5 cm was passed through a pressure resistance tester and exposed and developed, a very good level of blackening was set to 5 depending on a blackened area, and the worst level was 1 The following five-level ranking relative evaluation was performed. 3 is practical limit.

Evaluation of scratch resistance The surface of the film was rubbed with a scratch tester, and the amount of scratches was visually evaluated by a five-level ranking. The number of scratches was 5 and the number of scratches was 1. 3 is the practical lower limit.

Kutski evaluation test A sample was conditioned for 24 hours in a room at 23 ° C. and a relative humidity of 50%, 20 films were overlaid, and a load of 200 g / cm ² was applied for 3 days. Was visually observed and a 5-level relative evaluation was visually performed. The case where the number of marks attached to the film was the smallest was 5, and the case where the number was the largest was 1. 3 is practical limit.

(Developer composition) 1-phenyl-3-pyrazolidone 1.5 g hydroquinone 30 g 5-nitroindazole 0.250 g 5-methylbenzotriazole 0.06 g potassium bromide 3.0 g sodium sulfite 50 g potassium hydroxide 30 g boric acid 10 g Set to 1 liter. (The pH was adjusted to 10.20) As the fixing solution, a normal fixing solution was used.

Processing conditions: Konica automatic processor SRX-50
The treatment was performed at 34 ° C for 1 to 34 seconds at dry to dry 45 seconds.

The results of these evaluations are summarized in Table 2.

[0063]

[Table 2]

From the results in Table 2, by combining the emulsion of the present invention with the latex, a silver halide photographic element excellent in film physical properties can be obtained at the same time as high sensitivity photographic characteristics can be obtained. It can be seen that it is excellent in the resistance, scratch resistance, and scratch resistance.

[0065]

According to the present invention, there is provided a novel silver halide photographic element which improves the film physical properties of a silver halide photographic element, has high sensitivity and low fog, is excellent in pressure resistance and scratch resistance, and is free from scratches. I was able to.

Claims (1)

[Claims] 1. A photographic element comprising a support and at least a silver halide gelatin emulsion layer, wherein at least one layer of the photographic element comprises a tabular grain having an aspect ratio of 3 or more and a polymer having at least an isoprenesulfonic acid monomer unit. Silver halide photographic element containing the following latex.