JPH03260641A - High-sensitivity silver halide photographic sensitive material suitable for rapid processing - Google Patents

Abstract

PURPOSE:To enhance the sensitivity and sharpness of the photosensitive material and to eliminate the fixing defect, etc., by rapid processing by forming the emulsion surface on one side of a base having a prescribed thickness to the sensitivity higher than the sensitivity of the emulsion surface on the other side. CONSTITUTION:This photosensitive material consists of the silver halide emulsion layers formed on both sides of the base having <=130mum thickness. The emulsion surface on one side is formed to the sensitivity higher by >=1.5 times the sensitivity of the emulsion surface on the other side. The formation of the high-sensitivity emulsion layer on the side to be irradiated with light and the low-sensitivity emulsion layer on the opposite side therefrom is possible and the incorporation of silver iodobromide particles into the emulsion layers is possible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a silver halide photographic material, and particularly to a high-sensitivity silver halide photographic material suitable for rapid processing.

[Conventional technology]

Conventionally, for photosensitive materials that are irradiated with light from only one side of the photosensitive material, it has been common to provide a photosensitive silver halide emulsion layer on only one side of the photosensitive material. For example, CRT
Photographic X-ray films and indirect X-ray films are generally so-called single-sided photosensitive materials having a photosensitive silver halide emulsion layer on only one side of the film. Among direct X-ray films, mammography films, etc.
Those having a photosensitive silver halide emulsion layer on only one side are used.

These single-sided photosensitive materials have high sharpness because they are not affected by crossover light, compared to so-called double-sided photosensitive materials that have photosensitive silver halide emulsion layers on both sides of the support.

However, when trying to increase the sensitivity of single-sided photosensitive materials such as those mentioned above, a larger amount of photosensitive silver halide emulsion is coated on one side compared to double-sided photosensitive materials (for example, double-sided photosensitive materials for direct X-ray photography). I had no choice but to set it up.

However, when many silver halide emulsions are applied to one side of the support, processing problems arise. For example, when rapid processing is performed using an automatic developing machine, fixing failures often occur.

[Purpose of the invention]

The present invention aims to solve the above-mentioned problems of the prior art and provide a silver halide photographic material that is highly sensitive, has no problems even when processed quickly, and satisfies the requirements for high sharpness. It is something to do.

[Structure and operation of the invention]

The object of the present invention is to have at least one photosensitive silver halide emulsion layer on each side of a support having a thickness of 130 μm or less, and the sensitivity of the photosensitive silver halide emulsion layer on one side is such that the sensitivity of the photosensitive silver halide emulsion layer on one side is The sensitivity of the light-sensitive silver halide emulsion layer on the other side
This was achieved using a silver halide photographic material characterized by a high sensitivity of 1.5 times or more.

The present invention was completed against the following background.

That is, in order to solve the problems of the prior art and reduce the amount of emulsion per side while maintaining high sensitivity, the present inventor provided a high-sensitivity emulsion layer on one side of the support. attempted to provide a low-speed emulsion layer on the other side (opposite side), thereby keeping the amount of silver per side low and achieving high sensitivity.

However, it has been found through studies by the present inventors that when the thickness of the support is thick (for example, in the case of a film in which a thick support is used, such as a conventional film for CRT photography), the above-mentioned It has been found that using only this technique has the disadvantage that the sharpness is worse than when using a single-sided photosensitive material.

Furthermore, it has been found that there is also a problem in that sharpness deteriorates when the difference in sensitivity between the high-sensitivity side surface and the low-sensitivity side surface is small.

After further consideration of the above points, as in the present invention, the sensitivity on the high-sensitivity side is made 1.5 times or more higher than the sensitivity on the low-sensitivity side, and the thickness of the support is set to 13077 m or less. A photosensitive material of the present invention has been obtained in which all of the above-mentioned problems have been solved.

The present invention will be explained in more detail below.

The silver halide photographic material of the present invention has a thickness of 130 μm.
m or less, each of which has at least one photosensitive silver halide emulsion layer on both sides of the support.

In the present invention, the thickness of the support is 130 μm.
Any material can be used without limitation as long as it is less than m. As the support used in the present invention, it is preferable to use a flexible support commonly used for photographic materials. Useful as flexible supports are films of semi-synthetic or synthetic polymers such as cellulose nitrate, cellulose acetate, cellulose acetate butyrate, polystyrene, polyvinyl chloride, polyethylene terephthalate, polycarbonate, baryta paper or alpha-olefin polymers. (For example, paper coated with or laminated with polyethylene, polypropylene, ethylene/butene copolymer), etc.

The support may be colored using dyes or pigments.

The surface of these supports may be subjected to a subbing treatment, as is generally done, to improve adhesion to photographic emulsion layers and the like. The support surface is treated with corona discharge,
Ultraviolet irradiation, flame treatment, etc. may also be applied.

The thickness of the support is 130 μm or less, but 80 to 120 μm
More preferably, it is μm.

The silver halide photographic material of the present invention has at least one light-sensitive silver halide emulsion layer on each side of the support as described above, and therefore each side has one emulsion layer. It is also possible for each side to have two or more emulsion layers, or for one side to have one emulsion layer and the other side to have two or more emulsion layers. A protective layer is preferably provided on the surface of the photosensitive emulsion layer (on the surface opposite to the support).

In the silver halide photographic material of the present invention, the sensitivity of the light-sensitive silver halide emulsion layer on one side is 1.5 times or more as high as the sensitivity of the light-sensitive silver halide emulsion layer on the other side. Take composition. Sensitivity here refers to the sensitivity obtained from the sensitometric characteristic curve, ie, the reciprocal of the exposure amount required to obtain a constant photographic density. When comparing the sensitivity in this sense, the light-sensitive material of the present invention exhibits a high sensitivity in which the sensitivity of the emulsion layer on one side is 1.5 times or more as the sensitivity of the emulsion layer on the other side. Preferably it is 1.5 times or more and 10 times or less.

When the light-sensitive material of the present invention has one photosensitive silver halide emulsion layer on each side of the support, the above-mentioned sensitivity relationship only needs to be satisfied between the two aperture agent layers. When either side of the support has two or more photosensitive silver halide emulsion layers, the relationship between the overall sensitivity of one side of the support and the sensitivity of the other side of the support is as described above. It should be like this.

In the following explanation, the photosensitive emulsion layer on the side having a sensitivity 1.5 times or more higher than that on the other side is referred to as a high-sensitivity emulsion layer or high-sensitivity layer, and the photosensitive emulsion layer on the opposite side is referred to as a low-sensitivity emulsion layer. Sometimes referred to as a layer or a low-sensitivity layer.

The light-sensitive material of the present invention preferably has a high-sensitivity emulsion layer on the surface irradiated with light, and a low-sensitivity emulsion layer on the opposite surface.

Further, it is preferable that the amount of rooting is 1.1 times or more greater on the surface on the high-sensitivity emulsion layer side than on the surface on the other side.

The photosensitive silver halide emulsion constituting the light-sensitive material of the present invention may have any silver halide composition, such as silver iodobromide, silver bromide, silver iodide, silver chlorobromide, silver chloroiodobromide. , silver chloride,
Mixtures of these can be used. Preferably, the silver halide emulsion layer of the light-sensitive material of the present invention contains silver iodide-containing silver halide grains containing silver iodide in a range of 0.5 mol % to 5.0 mol %, especially iodobromide. It is preferable to contain silver particles.

In particular, when carrying out the present invention, a photosensitive material having a silver halide emulsion layer containing such silver iodide-containing silver halide grains in an amount of 60% or more of the total silver halide grains is preferred. etc.,
It can be dispersed in a suitable binder and present in the photographic constituent layer. Various hydrophilic colloids can be used as the binder, and gelatin is typically preferably used. As gelatin, in addition to lime-treated gelatin, acid-treated gelatin, enzyme-treated gelatin, gelatin hydrodispersions, oxygen dispersions, and other gelatin derivatives can be used. Materials made of synthetic polymers such as polyvinyl alcohol can also be used.

The same applies to the hydrophilic colloid used in the protective layer.

For the purpose of improving the physical properties of a coating film containing a hydrophilic colloid as a binder, it is preferable to use various film property improving agents, such as film hardening agents, as necessary. When using a hardening agent, the water absorption amount can be set to a desired value by controlling the amount added.

In the present invention, the temperature of the photosensitive silver halide emulsion layer is 50°C.
The dissolution time for sodium hydroxide is 15 minutes or more.
Preferably it is 30 minutes or less. More preferably, 1
The time is preferably 5 to 50 minutes.

Here, the dissolution time of the silver halide emulsion layer in sodium hydroxide is measured under the following conditions.

i.e. 1.5 at 50.0″C in a 500 mZ beaker.
Add 500 mZ of sodium hydroxide aqueous solution of % by weight,
Using this, measurements are performed using a rectangular sample measuring 1 cm x 5 cm as a measurement sample. During the measurement, the beaker containing the sodium hydroxide aqueous solution is kept in a constant temperature bath (water at a temperature such that the sodium hydroxide aqueous solution in the beaker is stabilized at a temperature of 50.0"C, usually around 50.2~51°C). Place the sample in a constant temperature bath (filled with water at a temperature of The time until the silver halide emulsion layer starts dissolving (at this time, the amount of silver halide eluted is usually about 1 to 3%) is measured, and this is defined as the dissolution time.

A more preferred embodiment of the present invention is that the thickness of the photographic constituent layer including the silver halide emulsion layer is 3.9 μm or less.

The photosensitive material of the present invention may contain other arbitrary additives, and these are listed in Research Disclosure 1.
Volume 76, 17643 (December 1978) and 18
It is described in Volume 7, No. 18716 (November 1976), and the relevant parts are summarized in the table below.

Known photographic additives that can be used in preparing the emulsion of the light-sensitive material according to the present invention are also described in the above two Research Disclosures, and the present invention will be further explained below with reference to Examples.

It goes without saying that the present invention is not limited to the examples.

Example 1 Silver iodobromide containing monodisperse grains of silver iodobromide containing 2.0 mol% of silver iodide and having an average grain size of 0.2 μm manufactured by Grain Ekuri Co., Ltd. as cores and containing w & 30 mol% of iodide. Grains were grown at pH 9.8, pAg 7.8, and then equimolar amounts of potassium bromide and silver nitrate were added at pH 8.2, pAg 9.1, resulting in iodobromide with an average silver iodide content of 2.2 moles. Average particle size of 0.375μm to become silver particles
emulsion grains (■-1), 0.640 μm emulsion grains (
■-2), 1.22 μm emulsion grains (■~3),
Four types of monodisperse emulsion grains of 0.88 μm emulsion grains (■-4) were prepared.

The emulsion was desalted to remove excess salts using a conventional flocculation method. That is, the temperature was maintained at 40°C, and an aqueous solution of a formalin condensate of sodium naphthalene sulfonate and magnesium sulfate was added to cause coagulation. After removing the supernatant liquid, pure water at 40°C was further added, an aqueous magnesium sulfate solution was added again to cause coagulation, and the supernatant liquid was removed.

Silver halide emulsion grains ■-1 thus obtained,
■-2, ■-3. ■-4 particle size dispersibility is S/r<0
．． 16, and had good monodispersity. (S is the coefficient of variation and t is the average particle size).

Manufactured by Hagi Ezari [F] Potassium bromide 2.1 was added to 5.51 of a 1.5% gelatin solution containing 0.17 mol of potassium bromide by the double jet method at 80°C and pH 5.7 with stirring.
mol and the equivalent of 2.0 mol of silver nitrate were added in solution over a period of 3 minutes. The pBr was maintained at 0.8 (consumed 0.53% of the total silver nitrate used). The potassium bromide solution addition was stopped and the silver nitrate solution continued to be added for 4.6 minutes (consuming 8.6% of the total silver nitrate used).

Then, potassium bromide solution and silver nitrate solution were added at the same time to 12
Added for 1 minute. During this time, the pBr was maintained at 1.15 and the addition flow rate was accelerated such that the completion time was 2.3 times the start time (43.6% of the total silver nitrate used was consumed). The potassium bromide solution addition was stopped and the silver nitrate solution was added for 1 minute (consuming 4.7% of the total silver nitrate used).

A 2.1 molar solution of potassium bromide containing 0.55 molar potassium iodide was added over 12.0 minutes along with the silver nitrate solution. The pBr was maintained at 1.7 during this time and the flow rate was accelerated to 1.5 times the starting rate at completion (consuming 35.9% of the total silver nitrate used). To this emulsion was added 1.5 g of sodium thiocyanate, 1 mol of Ag, and held for 25 minutes. 0.60 mol of potassium iodide and silver nitrate in solution,
pBr is 3 for about 5 minutes at a constant flow rate using the double jet method.
．． (approximately 6.6 of the total silver nitrate used)
% consumed). The total amount of silver nitrate consumed was approximately 11 moles. In this way, an emulsion containing tabular silver iodobromide grains with an average grain diameter of 1.80 μm and an aspect ratio of about 9:1 was prepared. These grains account for 80% or more of the total projected area of the silver iodobromide grains.

Evaluation of the silver halide emulsion grains ■ and ■ obtained in this way
Add pure water so that the volume per 1 mole is 500, and heat to 55°C. Spectral sensitizing dye A
and B in a weight ratio of 200:1, with a total amount of 820 mg of ■-1 per mole of silver halide.

■-2 is 600mg, ■-3 is 360mg, ■-4 is 5
00■, ■ is added as 600■-, and after 10 minutes, ammonium thiocyanate salt is added as ■-1 is 4X per mole of silver.
IO-'' moles, ■-2 is 2X10 moles, ■-3 is 1.
0X10-' mole, ■-4 is 1.6 Xl0-' mole, ■
was added as 3.times.10@-3 moles and appropriate amounts of chloroauric acid and hypo to start chemical ripening.

At this time, the pH was 6.15 and the silver potential was 50 mV.

15 minutes before the end of chemical ripening (70 minutes after the start of chemical ripening), 200 mg of potassium iodide was added per mole of silver,
After 5 minutes, 10% (imt/Vol) acetic acid was added and p
Reduce the tl value to 5.6 and keep that pH value for 5 minutes, then add potassium hydroxide 0.5% (wt/Vol)
The solution was added to return the pH to 6.15, and then 4-hydroxy-6-methyl-1,3,3a,7-titrazaindene was added, and after chemical ripening, emulsion grains ■1, ■-
2. ■-3. After mixing (1)-4 and (2) as shown in Table 1 below, a preparation solution (2) was prepared by adding the photographic emulsion coating additives described below.

To make each sample, emulsion grains were mixed as shown in Table 1. The numerical value of the composition ratio of particles is expressed as a percentage in terms of silver amount ratio.

After preparing the photographic emulsion coating solution, the pl+ was adjusted to 6.40, and the silver potential was adjusted to 74 mV (35°C) using a sodium carbonate and potassium bromide solution.

Using this emulsion coating solution, samples were prepared as follows.

That is, in the light-sensitive silver halide emulsion layer, the amount of gelatin in both the high-sensitivity emulsion layer side and the low-sensitivity emulsion layer side is 2. The amount shown in the table is maintained using the additives listed below.
A vJ solution was prepared, and the protective layer was coated with gelatin in an amount of 1.
15 (g/rrf) on both sides of the support at a speed of 80 m/min using two slide hopper type coaters, and dried in 2 minutes and 20 seconds to obtain a sample. As a support, glycidimethacrylate 50w
A copolymer aqueous dispersion obtained by diluting a copolymer consisting of three monomers, 10 wL% of methyl acrylate, and 40 wt% of butyl methacrylate to a concentration of 10 wt%, was applied as an undercoat liquid. As shown in Table 1, a blue-colored polyethylene terephthalate film hese for X-ray film having a thickness of 90 to 175 μm was used.

All samples obtained had a dissolution time of 15 to 20 minutes in sodium hydroxide at 60°C. (The method for measuring the dissolution time for sodium hydroxide is as described above).

The relative sensitivity of each side of the obtained sample was determined as follows. Namely, fluorescent intensifying screen KO-250 (sold by Konica ■),
Using only the back side, we prepared a sample that was photographed from the high-sensitivity layer side using the single-back method and a sample that was photographed from the low-sensitivity side. For each sample, the side opposite to the exposed side was removed with a proteolytic enzyme, leaving only the exposed side and the sensitivity of that side was measured. Tube voltage 90KVP, 20+
nA T:, X-rays were irradiated for 0.05 seconds, a sensitometric characteristic curve was created using the distance method, and the sensitivity and maximum density were determined from this. Sensitivity is sample No.
The relative sensitivity is expressed with the sensitivity of the high-sensitivity emulsion layer No. 1 as 100. Processing was carried out using Konica automatic processor 5RX-501.
Processing was performed in 5 second processing mode. XD-3R1 as developer
Xf-3R was used as a fixer. The fixing temperature of the automatic developing machine was 33°C, and the washing water was supplied at a temperature of 18°C at a rate of 1.52 per minute.

In addition, the system sensitivity of each sample was determined as follows.

That is, the fluorescent intensifying screen was applied to the high-sensitivity emulsion layer side, exposed to X-rays by a single back method, and developed in the same manner as above to form an image on each sample.

Regarding this, a sensitometric characteristic curve was obtained in the same manner as above, and the sensitivity was determined. This system sensitivity is the sample Nα
It is expressed as a relative sensitivity with the sensitivity for 1 being 100.

Note that each of the above relative sensitivities was determined as the reciprocal of the X-ray dose required to obtain a density of fog +0.7.

The spectral sensitizing dyes used for sample preparation are as follows.

(C112) 3sO3Na (CI42)3SO3 Spectral sensitizing dye B C2+15 zHs The additives used in the emulsion solution (coating solution for photosensitive silver halide emulsion) are as follows. Addition amount is silver halide 1
Expressed in amount per mole.

1.1-dimethylol-1-bromo-1-nitromethane 70■t-butyl-catechol 400■Polyvinylpyrrolidone (molecular weight 10,000) 1.
0 g Styrene-maleic anhydride copolymer 2.5 g Trimethylolpropane 10 g Diethylene glycol 5 g Nitrophenyl-triphenylphosodium chloride 501.1
g13-hydroxyhensen-4 ammonium sulfonate 4g2-mercaptobenzimidazole-5-sodium sulfonate 1,5 m
gAdditives used in the protective layer solution are as follows. The amount added is expressed per 11 coating liquids.

Lime-treated inert gelatin 68 g Acid-treated gelatin 2 g Polymethyl methacrylate, matting agent with an area average particle size of 3.5 μm 1.1 g silicon dioxide particles (matting agent with an area average particle size of 1.271 m) 0.5 g Ludox AM (DuPont) Colloidal silica > 30g2.
4-dichloro-6-hydroxy 1.3.5-) riazine sodium salt water ? @'
I11 2% (hardener) 12mj! Bisvinylsulfonyl methyl ether 0.5gCl1□C
00 (CI!□), C1h C+ + tb: +cONtl (CtlzCllJ)
sN 2.0 g Next, in order to evaluate the sharpness of these samples, a rectangular wave chart of each sample was subjected to X-ray imaging using a single hack method using KO-250, and the sharpness MTF was measured using a contrast method. The sharpness MTF is 2.0 spatial frequencies/ll1m.
showed the value of

The second measurement results are shown in Table 2.

Next, in order to check for poor fixing, each of Samples 1 to 13 was placed in the same Konica automatic processor 5RX-5RX-1 without being exposed to any light.
501 for 45 seconds. After dripping the residual silver assay solution shown below onto these samples and allowing them to air dry, Koni
Density was measured using light passed through a blue filter of a ca densitometer PDA-65. The evaluation was as follows.

-Residual silver concentration 0.03 or less (good)...O -Residual silver concentration more than 0.03 (unpractical)...x The results are shown in Table-2.

(Test solution prescription) NazS' 98zO6.15g in H and O for 10
00 cc finish As is clear from the results in Table 2, sample Nα7,8.12, which is a photosensitive material according to the present invention, has high sensitivity and high sharpness.
It is also found that the rapid processability is also good.

〔Effect of the invention〕

As described above, the silver halide photographic material of the present invention has the effects of high sensitivity, good rapid processing properties, and high sharpness.

Claims (1)

[Claims] 1. A support having a thickness of 130 μm or less has at least one photosensitive silver halide emulsion layer on each side, and the sensitivity of the photosensitive silver halide emulsion layer on one side is A silver halide photographic light-sensitive material characterized by having a high sensitivity of 1.5 times or more as high as the sensitivity of the light-sensitive silver halide emulsion layer on the other side.