JPH0251169B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a silver halide photographic material and a method for producing the same.

It is desired that silver halide photographic materials in recent years be suitable for rapid development processing. In particular, with the widespread use of automatic processors, it is necessary to obtain desired photographic properties in a certain period of time at high temperatures and in a short period of time.

It is known that silver halide developing agents, particularly p-dihydroxybenzenes such as hydroquinone, and 1-phenyl-3-pyrazolidones such as phenidone, can be incorporated into the silver halide emulsion layer or its adjacent layer to increase the development speed. As a result, a photographic material suitable for processing with an automatic processor can be obtained.

As is well known, it is desirable that the hydrogen ion concentration (PH) of a hydrophilic colloid solution containing a developing agent be as low as possible for the stability of the developing agent.

On the other hand, as supports for photographic light-sensitive materials suitable for rapid processing, supports having a polyolefin surface, typified by polyethylene-coated paper supports, are well known. The polyethylene layer typically contains up to 15% by weight of white inorganic pigments such as titanium dioxide and zinc oxide. If the amount of white pigment exceeds that amount, it becomes difficult to mix in the polyethylene because of deterioration in extrusion coating workability, physical properties, etc. Therefore,
There are limits to the improvement of whiteness, hiding power, etc. by white pigments.

By the way, when a hydrophilic colloid photographic layer containing a developing agent is coated and dried on a support having a polyolefin surface, spot-like fog (known as "pochi" by those skilled in the art) caused by fine metal powder etc. may occur. A serious problem arises in which the occurrence of multiple occurrences of These spots are caused by certain types of dust in the atmosphere or fine particles of heavy metals that adhere to the surface of the support during the manufacturing process, or that are mixed into the photographic layer during the manufacturing process of photographic light-sensitive materials. It is generally known that it is used for adhesion. Various so-called spot prevention agents are known, but many of them are not sufficiently effective or cause other side effects such as desensitization and fogging.

An object of the present invention is to provide a silver halide photographic material which is suitable for rapid processing and has improved whiteness, hiding power, etc. and prevents the occurrence of spots, and a method for producing the same.

Other objects and advantages of the present invention will become apparent in the following description of the specification.

The present invention has a hydrophilic colloid layer containing a white inorganic pigment on a support whose surface has been activated with a polyolefin, and a silver halide emulsion layer on top of the hydrophilic colloid layer. It basically consists of a silver halide photographic material containing a silver developing agent.

The present invention will be explained in more detail below.

The developing agents used in the present invention include p-dihydroxybenzene developing agents such as hydroquinone, methylhydroquinone, and chlorohydroquinone, 1-phenyl-3-pyrazolidone (phenidone), 1-phenyl-4-methyl-3-pyrazolidone, 1-phenyl-4,4-dimethyl-3-pyrazolidone, 1-phenyl-4-hydroxymethyl-3-pyrazolidone, 1-phenyl-4,4-
3 such as dihydroxymethyl-3-pyrazolidone, 1-phenyl-2-acetyl-3-pyrazolidone, etc.
-Pyrazolidone-based developing agents are preferred.

As mentioned above, silver halide emulsions containing a developing agent usually have a pH as low as about 4 to 45 for the stability of the developing agent. When containing phenidone or a combination thereof with hydroquinone, it is particularly desirable to have a low pH as described above. When a relatively stable developing agent, that is, a developing agent having relatively low development promoting activity (for example, 1-phenyl-4,4-dimethyl-3-pyrazolidone) is contained, the pH can be increased to some extent.

Each contains a developing agent and has a pH of 4.2 and 6.2.
When the silver halide emulsion was coated on a polyethylene-coated paper support, it was found that the latter had clearly fewer spots than the former, and the size of the spots was also smaller.

However, although the means of increasing the pH of a silver halide emulsion containing a developing agent are advantageous, they are not sufficiently effective and there are limits to the extent to which the pH can be increased.

It has been found that the objects of the present invention can be achieved even by using a silver halide emulsion containing a developing agent and having a pH of 4.2. One embodiment of the present invention according to its typical example is to apply a hydrophilic colloid coating solution of pH 6.2 containing titanium dioxide on a paper support treated with corona discharge and coated with polyethylene containing titanium dioxide. It is manufactured by simultaneously coating a silver halide emulsion with a pH of 4.2 containing a developing agent in multiple layers and drying.

The support used in the present invention is polyethylene,
The surface of a polyolefin such as a paper support coated with polypropylene, a polyethylene film, a polypropylene film, etc. is activated. Activation treatments for the polyolefin surface include treatment methods known in the art such as corona discharge treatment and flame treatment. Further, in order to prevent the attenuation of the corona discharge treatment, the support may be coated with a thin subbing layer of gelatin or the like immediately after the corona discharge treatment to prevent deterioration of adhesive properties. Further, the polyolefin layer may contain a white inorganic pigment such as titanium dioxide or zinc oxide. However, as mentioned above, in order to improve the operational troubles and deterioration of physical properties during polyolefin film formation due to the inclusion of pigments, it is possible to reduce the content of pigments, and it is also possible to eliminate them altogether. have. The polyolefin layer may further contain a hue improver, a fluorescent whitening agent, an antistatic agent, an antioxidant, a lubricant, and the like.

A hydrophilic colloid layer containing a white inorganic pigment is provided on the support of the present invention. As the white inorganic pigment, rutile type or anatase type titanium dioxide is preferable, but zinc oxide, barium sulfate,
Titanium phosphate, calcium carbonate, etc. can also be used. As the hydrophilic colloid, natural or synthetic binders well known to those skilled in the art are used, such as gelatin, polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose, polyvinylpyrrolidone, and the like. The colloid layer containing white pigment is
Considering the adverse effect on the silver halide emulsion layer containing the developing agent, it is desirable that the pH is in the range of about 4 to 5, but in order to achieve the purpose of the present invention, the pH should be about 5.
Above, it is preferably in the range of about 5.5 to about 6.5. The amount of hydrophilic colloid is desirably about 0.5g or more per square meter;
It is about g/ ^m2 . The white inorganic pigment is about 20% by weight or more, preferably 30% to 200% by weight based on the hydrophilic colloid, and about 0.3% by weight per square meter.
~3g. Although the colloid layer containing the white pigment can be coated on the support in advance, it is more preferable to coat the colloid layer simultaneously with the silver halide emulsion in order to achieve the objective. This not only reduces the number of steps, but also reduces the chances of spots occurring. The silver halide emulsion provided adjacent to the colloidal layer containing the white pigment can be produced by a known and conventional method, and can be produced by using silver chloride, silver chloride,
Silver bromide, silver chlorobromide, or silver halide mixed with silver iodide can be used. Mercapto compounds, azaindene compounds, etc. may be added for the purpose of preventing or stabilizing fog, and optical sensitization may be performed using merocyanine, cyanine dyes, etc. A coupler may also be included.

The PH of the silver halide emulsion containing the developing agent can range from about 4 to about 6.5. Preferably the PH ranges from about 5 to about 6.5. The developing agent is
It can also be contained in photographic layers such as colloid layers and protective layers containing white pigments.

The developing agent is water or a water-miscible organic solvent such as methanol, ethanol, isopropanol,
Dissolved in dimethylformamide, acetone, etc.
It can be applied to silver halide emulsion layers. The amount added varies depending on the purpose of use. 30mg/m ² for dihydroxybenzene developer, especially 50mg/m 2
It ranges from more than mg/m ² to about 2 g/m ² . For 3-pyrazolidones, the amount is 5 mg/m ² , particularly from 10 mg/m ² or more to about 1 g/m ² . Of course, it is possible to use a dihydroxybenzene developer and a 3-pyrazolidone developer in combination.

The amount of binder applied in the emulsion layer is generally 1 to 15
g/m ² , preferably 2 to 10 g/m ² .

As the hydrophilic binder, in addition to gelatin, natural or synthetic binders well known to those skilled in the art, such as gelatin derivatives, polyvinyl alcohol, polyvinylpyrrolidone, and carboxymethylcellulose, can be used.

Each photographic coating solution also contains surfactants, hardeners, ultraviolet absorbers, development regulators, PH regulators, matting agents, antistatic agents, fluorescent brighteners, synthetic polymer latexes, and plasticizers. It may contain agents, thickeners, etc.

Example 1 After chemically ripening a silver chlorobromide gelatin emulsion containing 5 mol% of silver bromide, sensitizing dyes, stabilizers, hardeners, surfactants, etc. were added to the emulsion to give an additional amount of 0.3 g/ ^m2 . of hydroquinone was added to adjust the pH to 4.8. In addition, a gelatin solution containing titanium dioxide was prepared and the pH was adjusted to 6.2. A paper support coated with polyethylene containing titanium dioxide is treated with corona discharge, and the above silver halide emulsion is applied thereon together with a gelatin protective solution, or the above gelatin solution of titanium dioxide, silver halide emulsion and gelatin protective solution are each extruded. Apply multiple layers with Rougeyon Burr,
Dry. The white layer contains titanium dioxide 0.6g/m ² and gelatin 0.8g/m ² , the silver halide emulsion layer contains gelatin 1.7g/m ² and silver 1.5g/m ² , and the protective layer contains gelatin 1.0
The coating amount was g/m ² . After cutting the obtained sample,
Apply uniform exposure to obtain a density of about 0.3,
It was developed and fixed using an ordinary black and white photographic developer. Titanium dioxide - The sample without gelatin layer had an extremely large number of black spots, but titanium dioxide -
The sample with the gelatin layer had no black spots at all. Furthermore, when fine line characters were printed and processed using an automatic processor, the samples of the present invention were superior in whiteness, sharpness, and resolution compared to comparative samples.

No abnormality was observed in the photographic properties of the sample of the present invention even when it was stored at 50° C. and 80% RH for 5 days.

Example 2 The same procedure was carried out except that the hydroquinone used in the silver halide emulsion of Example 1 was changed to 1-phenyl-4,4-dihydroxymethyl-3-pyrazolidone at 0.2 g/m ² and the pH was adjusted to 6.2. Example 1 was repeated. A small number of black spots were observed in the comparison sample, but no black spots were observed in the sample of the present invention.

Example 3 Titanium dioxide in the present invention sample of Example 1
The effect of the present invention was also confirmed in a sample in which the pH of the gelatin layer was adjusted to 5.3.

Example 4 After corona discharge treatment on the surface of polypropylene film, titanium dioxide 2.1 g/m ² and gelatin 1.6
A coating liquid with a pH of 5.8 and the silver halide emulsion of Example ² was coated and dried in the same manner. The effects of the present invention were confirmed.

Example 5 The effect of the present invention was also confirmed in the sample of Example 1 in which the pH of the silver halide emulsion layer was adjusted to 4.2. The sample in which the pH of the titanium dioxide-gelatin layer was set to 4.2 produced a small number of black spots, but the size was smaller.

Example 6 Example 1 was repeated except that the titanium dioxide-gelatin layer of Example 1 was replaced with a barium sulfate-gelatin layer. The same results as in Example 1 were obtained. It should be noted that the supports used in all Examples had a small amount of fine iron powder evenly adhered to the surface thereof after being subjected to corona discharge treatment.

As a result of implementing the present invention in a production facility, the superiority of the present invention was confirmed with good reproducibility.

Claims (1)

[Scope of Claims] 1. A hydrophilic colloid layer containing a white inorganic pigment and having a hydrogen ion concentration of about 5 or more on a support whose surface has been activated with polyolefin, and a hydrophilic colloid layer adjacent to the hydrophilic colloid layer. 1. A method for producing a silver halide photographic material, which comprises providing a silver halide emulsion layer containing a developing agent. 2 The hydrogen ion concentration of the hydrophilic colloid layer is approximately 5.5
~6.5 The manufacturing method according to claim 1. 3 The white inorganic pigment is about 20% of the hydrophilic colloid.
~200 weight percent of claim 1
The manufacturing method according to item 1 or 2. 4. The manufacturing method according to claim 1, wherein the developing agent is selected from p-dihydroxybenzenes and 1-phenyl-3-pyrazolidones. 5. The manufacturing method according to any one of claims 1 to 4, wherein a hydrophilic colloid layer and a silver halide emulsion layer are simultaneously coated in a multilayer manner.