JPS63249843A - Silver halide photographic sensitive material - Google Patents

Abstract

PURPOSE:To improve the surface gloss of the titled material by incorporating an aqueous dispersion of a copolymer substantially composed of styrene and/or styrene derivatives, an acrylate and an unsatd. carboxylic acid, and a colloidal silica in the hydrophilic colloidal layer of the outermost layer of the titled material, respectively. CONSTITUTION:In the titled material mounted at least >=2 layers of the hydrophilic colloidal layer on a supporting body, the hydrophilic colloidal layer of the outermost layer of the titled material contains the aqueous dispersion of the copolymer substantially composed of the styrene and/or the styrene derivative, the acrylate and the unsatd. carboxylic acid, and also the colloidal silica. Said aqueous dispersion of the copolymer is produced by emulsion polymerization method. The titled material which has the improved surface gloss and the high reflection density is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Industrial Application Field The present invention relates to a silver halide photographic material, and more particularly to a photographic paper with improved surface gloss.

(B) Prior art and intervening layer point photographic paper has at least one light-sensitive emulsion layer on an opaque support consisting of paper, baryta paper, polymer laminated paper, polymer film provided with an opaque layer, etc. ,
Surface protective layer, and optional intermediate layer, filter layer,
It has an undercoat layer and a shoeing layer.

Since the photographic image formed on the support of photographic paper is observed using reflected light, the quality of the image is greatly influenced by the reflection density of the image.

As one means for increasing the reflection density of photographic paper, efforts have been made to increase the surface gloss of photographic paper.

For example, by providing a baryta layer, a polymer laminate layer, etc. on the surface of the support, and then coating a photosensitive emulsion layer thereon, the smoothness of the surface of the photographic paper can be improved. A heated metal plate (so-called ferrotype) that has a mirror finish on the surface of photographic paper after the development process is completed.
Conventionally, methods of increasing the surface gloss by so-called ferrotyping, in which the surface of photographic paper is made mirror-like by drying it in contact with paper, and a method of combining both methods are well known.

・In recent years, photographic paper has become thinner as an energy-saving material, and with the thinning of the support, it is coated on the support, and the photosensitive emulsion layer, surface protection layer, and other layers are coated on the support at high humidity or low humidity. Due to the increase in curls, thinning is required,
At such times, thinning of the protective layer results in a decrease in surface gloss.

Furthermore, in recent years, there has been a demand for faster development processing, and for this reason, it is necessary to make the coating layer thinner, and maintenance and improvement of surface gloss has become an extremely important issue from that point of view as well.

Japanese Patent Publication No. 56-24253 discloses a technique in which lime-treated gelatin having a jelly strength of 3001 or more is used as the top layer, but if the top layer is made thinner, the effect will be less.
The decrease in gloss and the resulting decrease in density lead to a decrease in the commercial value of photographic paper. Furthermore, patent application 58-11
In 2491, a technique is proposed in which a desalted lime-treated ossein gelatin layer with a jelly strength of 3002 or more and a calcium content of IQ OOppm or less is used as the top layer, but it is difficult to thin the light-sensitive emulsion layer and the surface protective layer. As this progresses, the gloss tends to decrease.

On the other hand, in Japanese Patent Publication No. 57-10416, there is a technique in which colloidal silica is contained in the top layer and vinyl polymer is contained in the emulsion layer, but this technique cannot be expected to produce much gloss, and it is necessary to make the top layer thinner. However, the effect is not so great, and furthermore, when colloidal 7-liquid is added to the top layer, the white background of the photographic image becomes less glossy, making it undesirable for photographic paper.

Furthermore, when the surface contains and exposes colloidal silica,
Due to long-term exposure to light and heat during long-term exhibitions, the surface of photographic paper tends to crack, leading to a decline in product value.

On the other hand, JP-A-50-56931 and JP-A-53-46018
No. 58-137831, No. 53-46018,
No. 54-109831, No. 54-76137, etc. disclose techniques for aqueous copolymer dispersions contained in photographic materials. However, when the copolymer aqueous dispersions used in these prior art are used in the outermost layer, they become desensitized and
Increased fogging, devitrification during development, and cracks on the surface of photographic paper due to long-term exposure to light and heat during long-term exhibition, etc.
There are defects that tend to cause a decrease in gloss, leading to a decrease in product value.

(C) Purpose of the Invention The first purpose of the present invention is to provide a photographic material with increased surface gloss and high reflection density. The second objective is to provide a photographic material that does not cause image deterioration during long-term exhibition.

CD) Structure of the Invention The object of the present invention is to provide a silver halide photographic material having at least two or more hydrophilic colloid layers on a support, in which styrene and/or styrene is contained in the outermost hydrophilic colloid layer. A photosensitive photosensitive material containing an aqueous copolymer dispersion consisting essentially of a derivative, an acrylic ester, and an unsaturated carboxylic acid, and containing colloidal silica in the outermost hydrophilic colloid layer. This was achieved through materials.

First, an aqueous copolymer dispersion consisting essentially of styrene and/or styrene extractor, acrylic, ester, and unsaturated carboxylic acid used in the present invention will be described. Styrene and/or styrene derivatives include styrene, alkylstyrenes such as methylstyrene, ethylstyrene, and inglobylstyrene, halogenated styrenes such as chlorostyrene, bromustyrene, and fluorostyrene, methoxystyrene, ethoxystyrene, and butoxystyrene. Alkoxystyrenes such as styrene, P-hydroxystyrene, 3
- Hydroxystyrenes such as methoxy-4-hydroxystyrene, carboxystyrenes and derivatives thereof such as vinylbenzoic acid and methyl vinylbenzoate, nitrostyrene,
Nitrated suderenes such as trinitrosteref, aminostyrenes such as m-aminostyrene and dimethylaminostyrene, styrene derivatives containing sulfur such as ethyl P-vinylbenzenesulfonate, and substituted substances at the 4- and β-positions. Can be mentioned.

Examples of the ester residue of the acrylic acid ester include tert-methyl, ethyl, n-7'-propyl, 1so-propyl, 2-ethylhexyl, tesyl, and the like. Again 1
, 1.3)') May be substituted with a halogen atom such as hydroperfluoropropyl.

Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, itaconic acid, and maleic acid.

The ratio of styrene and/or styrene derivative, acrylic acid ester, and unsaturated carboxylic acid preferably used in the present invention is such that the content of styrene and/or styrene derivative is 10 to 70% by weight, particularly 30 to 70% by weight. Preferably it is 60%. In addition, the content of unsaturated carboxylic acid is 1
It is preferably from 1 to 10% by weight, particularly from 1 to 5ts. Also, the acrylic ester can be selected arbitrarily.
Furthermore, other monomer components may be contained within a range that does not substantially impair the effects of the present invention.

The copolymer aqueous dispersion of the present invention is produced by an emulsion polymerization method. In order to produce this, a solution obtained by adding an emulsifying dispersant such as ammonium persulfate and a polymerization accelerator such as sodium sulfite to a flask equipped with a reflux condenser and a stirrer is mixed while stirring while maintaining the temperature at about 60°C. When the polymerization component monomer is added dropwise and polymerized, an aqueous copolymer dispersion is obtained. The amount of surfactant used in the reaction is 5% by weight or less, especially 1% by weight based on the copolymerization component monomer.
Weight - Front and back is best. The particle size of the copolymer in the resulting dispersion varies depending on conditions such as the amount of surfactant used, stirring conditions, and polymerization temperature, but it is usually 0.1μ or less, especially 0.05μ or less. preferable.

Although the copolymer aqueous dispersion of the present invention is effective when used in the emulsion layer, intermediate layer, etc. of a light-sensitive material, it is particularly effective when added to the outermost layer, such as a protective layer. At that time, since it is mixed with gelatin in a free ratio, there is no particular restriction on the amount added to gelatin, but it is about 3 to 1001 amounts to gelatin, especially 5
It is preferable to use up to 70% by weight.

Next, the composition of a typical copolymer contained in the aqueous copolymer dispersion used in the present invention is shown below, but the present invention is not limited thereto.

Further, the colloidal silica used in the present invention is mainly a colloidal solution in which ultrafine particles (particle size of 50 mμ or less) of silicic anhydride (silica) are dispersed in water using water as a dispersion medium. It also includes silica containing as an alkali component, an inorganic salt such as sodium hydroxide, lithium hydroxide, ammonium hydroxide, or an organic salt such as tetramethylene ammonium ion as a stabilizer. In addition, as commercially available products, the daily chemical substances Snowtex 20, Snowtex 30, Snowtex C, Snowtex N1, Snowtex O.

Snowtex S, Ludotsux AM1 Ludotsux SM, Ludotsux H8, etc. manufactured by DuPont are available.

In the present invention, colloidal silica is used in a binder containing hydrophilic colloid (mainly gelatin) in the outermost layer.
~150% by weight, preferably 10-100% by weight.

Similarly, colloidal silica can be effective when used in photosensitive silver halide photographic emulsion layers, intermediate layers, etc., but it is especially effective when added to the outermost layer, such as a protective layer.

If the colloidal silica used in the present invention is used alone or in large amounts in the outermost hydrophilic colloid layer, an increase in surface gloss can be expected. It has the disadvantage that cracks easily occur on the surface of the photographic paper. To this end, an aqueous copolymer dispersion of styrene and/or a styrene derivative, an acrylic ester, and an unsaturated carboxylic acid is contained in the hydrophilic colloid in the outermost layer. It does not have the drawbacks of colloidal silica, that is, the surface of the photographic paper does not crack even when exposed to light and heat for long periods of time, such as during long-term exhibitions, and the colloidal silica and styrene used in the present invention and/or It has been found that the surface gloss is significantly improved compared to when an aqueous copolymer dispersion of a styrene derivative, an acrylic acid ester, and an unsaturated carboxylic acid is used alone.

Furthermore, it has been found that even if the amount of colloidal silica is increased in a system in which the aqueous copolymer dispersion of the present invention is present, surface cracking, which is a drawback of colloidal silica, does not occur, and the surface gloss is further improved.

In the present invention, it is most effective when used in the outermost layer as described above, and in this case, gelatin and gelatin derivatives are used as hydrophilic colloid substances as binders. Furthermore, there is nothing wrong with using a matting agent such as polystyrene, polymethyl methacrylate, or silica in the uppermost layer consisting of a copolymer and a binder, if necessary.

The surface protective layer in the present invention preferably contains an appropriate amount of a hardening agent and a surfactant. Specific examples of hardening agents include aldehyde compounds such as formaldehyde and geltaraldehyde, tetone compounds such as cya-7tyl and microbendione, and bis(2-chromityl urinary IA)-
2-Hydroxy-4,6-dichloro-1,3,5) riazine, compounds with reactive nolognes as described in U.S. Pat. No. 3,635,718, divinyl sulfone, reactive olefins as described in U.S. Pat. No. 3,635,718. compounds, N-methylol compounds as described in U.S. Pat. No. 2,732,316, iso-7 ananates as described in U.S. Pat. No. 3,103,437, U.S. Pat.
aziridine compounds as described in US Pat. No. 3,100,704, epoxy compounds as described in US Pat. No. 3,091,537, halogen carboxaldehydes such as mucochromic acid, dioxane derivatives such as dihydroxydioxane, chromium Inorganic hardeners such as alum, potash alum, and zirconium sulfate may be used alone or in combination of two or more. Specific examples of surfactants include natural surfactants such as saponin, nonionic surfactants such as alkylene oxide, glycerin, and glycidol, higher alkylamines, quaternary ammonium salts, pyridine, and other complexes. Cationic surfactants such as rings and sulfonitams, anionic surfactants containing acidic groups such as carboxylic acids, phosphoric acids, sulfuric acid ester groups, and phosphoric ester groups, amino acids, aminosulfonic acids, and sulfuric acid or phosphoric acid esters of amino alcohols. These amphoteric surfactants can be used alone or in combination of two or more.

Silver halogenide emulsions used in the practice of the present invention are known,
Methods for producing and dispersing silver halide that can be prepared by conventional methods, silver halide composition (for example, silver chloride,
(silver bromide, silver iodobromide, silver chlorobromide, etc.), the size and crystal habit of silver halide grains, the ratio of silver halide grains to gelatin, the pH and PAg of silver halide emulsions, and the use of chemical sensitizers. There are no limitations on the types and amounts of branches, the types and amounts of other additives, the types and amounts of gelatin and other binders, etc.

Supports used in the silver halide photographic material of the present invention include paper laminated with baryta or polyolefin resin, a transparent film made opaque by adding a pigment such as titanium oxide, and a cellulose acetate film. polystyrene film,
Examples include polyethylene terephthalate film, polycarbonate film, and other types of films.

(E) Examples The present invention will be explained in detail with examples below, but the present invention is not limited to these embodiments.

Example 1 Silver chlorobromide emulsion (Br:C2=6
0:40) as silver on corona discharge machined polyethylene laminated paper (glossy) support, 1.4 f/R, gelatin 4 t/rr? Add 1. gelatin to the surface protective layer so that ! Coating was carried out simultaneously using a slide hopper type extrusion coating machine so that the coating amount was M/m''.

However, the proportion of the exemplified compound as a binder in the surface protective layer (
The samples were coated and dried so that the weight) was 0.15% (sample 1.2.4.6.) and 30% (sample 3.5.7). Next, apart from these samples, acrylonitrile-butadiene latex (compound F; butadiene/
Acrylonitrile = 30/70), acrylate latex (compound G; n-butyl acrylate), and colloidal silica (compound) 1) were used, and the proportion (weight) of the compound was 15% (sample 8.10.12. )
and 30 inches (referred to as sample 9.11.13).

Furthermore, compounds A1C, E, and compounds F-H were applied in combination so that the proportion (weight) of each compound was 15% (
Samples 14-22).

Table 1 shows the surface glossiness and maximum reflection density (Dmax) of the white background and black background of samples 1 to 22, respectively. Among these values, the gloss value of the white background area is determined by performing normal photographic processing on each sample in an unexposed state, and the gloss value of the black background area is determined by exposing each sample to appropriate light and performing normal photographic processing. Photographic processing was performed, and Dmax was a value measured after normal sensitometry and photographic processing were performed and the film was left to dry naturally. The surface gloss value here is VG-I manufactured by Nippon Kishoku Kogyo.
DQ Gloss Gloss] Measured at an incident angle of 60' and a light receiving angle of 60°. At the same time, their D max are shown in the same Table 1. The measured value of reflection density here is based on the method described in JI8-7611.

Next, the developed sample was placed outdoors (yp where sunlight is directly exposed).
After about one month, the surface condition was compared with that of a sample that had not been left for a month. Those with almost no change were marked with a circle, and those with changes were marked with a circle (specifically, the surface of the photosensitive material was a turtle shell). Items marked with an X are also shown in Table 1.

(Hereinafter in the margin) Table 1 As is clear from Table 1, the compounds of the present invention (A, C, B)
and colloidal silica (compound) 1) (samples 20 to 22) are copolymers, those that do not contain colloidal silica (sample 1), and combinations of other compounds (A-H) and compounds. It is clear that both the surface gloss of the black background part and the Dmaz light resistance are superior to those of (Samples 2 to 19).

Example-2 Gelatin prepared by the same method as Example-1
1 as a binder for the surface protective layer in the silver halide emulsion.
The proportion (weight) of the exemplary compounds (A, C, F) is 30%,
Furthermore, a sample (23-32) in which the ratio (weight) of compounds F and H was combined at 30% and 0%, and a sample without the compound (33)
are shown in Table 2.

Table 2 shows the white background gloss, black background gloss, maximum reflection density (Dmax), and light resistance of each sample using the same method as in Example-1.

Table 2 As is clear from Table 2, the compounds (A, C) of the present invention
Samples (25, 26, 29, 30) in which compound H colloidal silica was increased in the presence of
It can be seen that both ax and light resistance are excellent.

Claims (1)

[Claims] In a silver halide photographic light-sensitive material having at least two or more hydrophilic colloid layers on a support, the outermost hydrophilic colloid layer contains styrene and/or styrene derivatives, acrylic esters, and unsaturated carboxylic acids. What is claimed is: 1. A photographic light-sensitive material, which contains an aqueous copolymer dispersion consisting essentially of an aqueous copolymer dispersion, and further contains colloidal silica in a hydrophilic colloid layer as the outermost layer.