This invention relates to a light-sensitive silver halide photographic material, more particularly to a light-sensitive silver halide color photographic material which is excellent in fastness to light, and further excellent in sharpness without impairing whiteness of the white portion.
As a method for forming a dye image by use of a light-sensitive silver halide color photographic material, there may be mentioned the method in which the dye image is formed by the reaction between a coupler for photography and the oxidized product of a color developing agent. As the couplers for photography for effecting conventional color reproduction, respective couplers of magenta, yellow and cyan have been employed and, as the color developing agent, aromatic primary amine type color developing agents have been used, respectively. Through the reaction of the respective couplers of magenta and yellow with the oxidized product of an aromatic primary amine type color developing agent, dyes such as azomethine dye, etc., are formed, while through the reaction of a cyan coupler with an aromatic primary amine type color developing agent, dyes such as indoaniline dye, etc., are formed.
Among them, for formation of magenta color images, 5-pyrazolone, cyanoacetophenone, indazolone, pyrazolobenzimidazole, pyrazolotriazole type couplers are used.
Most of the magenta color image forming couplers practically used in the prior art were 5-pyrazolone type couplers. The color image formed from a 5-pyrazolone type coupler is excellent in fastness to light or heat but the tone of this dye is not satisfactory and unnecessary absorption having yellow components exist at around 430 nm. Also, due to the broad absorption spectrum of visible light at around 550 nm, color turbidity is caused to give a photographic image which lacks sharpness.
As the coupler having no such unnecessary absorption, 1H-pyrazolo[3,2-c]-s-triazole type couplers, 1H-imidazo[1,2-b]-pyrazole type couplers, 1H-b pyrazolo[1,5-b-]pyrazole type couplers or 1H-b pyrazolo[1,5-d]tetrazole type couplers as disclosed in U.S. Pat. No. 3,725,067, Japanese Provisional Patent Publication Nos. 162548/1984 and 171956/1984 are particularly excellent.
However, the magenta dye image formed from these couplers is markedly low in fastness to light. When these couplers are used for light-sensitive materials, particularly for light-sensitive materials suitable for direct viewing, the essential necessary conditions of photographic materials to record and store images will be impaired, thus involving a drawback in practical application.
For improvement of fastness of these color images to light, a number of methods have been proposed in the prior art. As the typical methods, there have been practiced the method in which the dye itself formed from the coupler is made fast and the method in which fastness is improved by addition of various fading preventives. The method of adding a fading preventive is an effective fading preventing means and is frequently used.
As the compound for improving fastness of a dye image to light, there may be included, for example, hydroquinone derivatives disclosed in U.S. Pat. Nos. 2,360,290, 2,418,613, 2,675,314, 2,701,197; derivatives of couromane or coumarane disclosed in U.S. Pat. Nos. 3,432,300, 3,573,050, 3,574,627, 3,764,337, 3,574,626, 3,698,909, 4,015,990; p-alkoxyphenols disclosed in U.S. Pat. Nos. 3,457,079 and 3,069,262; Japanese Patent Publication No. 13496/1968; etc.
However, these compounds are not satisfactory in their effects. On the other hand, light fastness improvement techniques with metal complexes are disclosed in Japanese Provisional Patent Publication Nos. 99340/1981, 168652/1981 and 51834/1985. These metal complexes are effective as the agent for imparting light fastness, but the metal complex itself is greatly colored, thus having the drawback that the white portion of the photographic image appears tinted with yellow, yellowish green or green.
Accordingly, it has been desired to improve light fastness by use of a metal complex in combination and also improve whiteness of the white portion. As improvement of whiteness, there have been employed in the prior art the methods which can be broadly classified into two categories. One category is the method in which whiteness of the original paper support itself is improved as disclosed in Japanese Provisional Patent Publication No. 19021/1978, and the other is the method in which an oil-soluble dye is used as disclosed in Japanese Provisional Patent Publication No. 93150/1980. Improvement of whiteness of the original support paper itself is determined depending on the properties of the titanium oxide contained in the original paper and therefore it is difficult to improve whiteness to a great extent.
Improvement of whiteness with an oil-soluble dye can be easily used in a light-sensitive silver halide photographic material and the extent of the improvement of whiteness is effectively greater.
Accordingly, the present inventors have made various investigations, and consequently found surprisingly that by using in combination at least one of a specific class of metal complexes and at least one of oil-soluble dyes, and further at least one of a specific class of magenta couplers, light fastness of color image can be improved without impairing whiteness of the white portion of photographic image, and further sharpness of the dye image can be improved.
Particularly, the effects of improvement of light fastness and sharpness for the color image obtained from the specific class of magenta couplers used in the above combination of the present invention surpass greatly the improved effect expected from the combined use with the couplers of the prior art, and this could not be expected at all from any of the above prior art techniques.
USPTO Backgrounds
USPTO Backgrounds