JP2633011B2 - Photographic support - Google Patents

Description

The present invention relates to a photographic support in which paper is used as a substrate (hereinafter, the substrate paper is referred to as base paper) and both surfaces of which are coated with a polyolefin resin. The present invention relates to a photographic support in which the whiteness of the resin surface on which an image is formed is improved. More specifically, the present invention relates to a fluorescent agent which exhibits a tendency to have a yellow tint due to titanium oxide contained in a high concentration in a resin layer on the image forming side of a resin-coated paper-type photographic support, particularly a rutile type titanium oxide. The present invention relates to a photographic support in which the whiteness is improved by remarkably reducing the amount by adding the compound into a resin layer.

(Prior art)

Recently, as a photographic support excluding a film photosensitive material, a waterproof support in which both sides of a base paper having high sizing properties are coated with a polyolefin resin, particularly a polyethylene resin, has become mainstream. The reason for this is that the resin-coated waterproof support meets the demand for automation and rapid development of photosensitive materials, especially photographic paper.

However, the resin layer on the image forming side of the resin-coated paper-type photographic support contains titanium oxide due to image sharpness and other requirements mainly due to photographic performance. And
Since the titanium oxide pigment has a yellow tint, the whiteness of the white background portion of the photographic image becomes insufficient as it is.

Especially in the case of color photographic paper widely used in recent years,
Since it is required that the color reproduction be faithful and the color be vivid, the support is required to have a clear white color without any coloring.

In addition, while the technology relating to titanium oxide pigments and resins has progressed, the demand for improved sharpness or sharpness of color images and black-and-white images has increased, and resin-coated paper-type photographs have a resin layer on the support side on which an image is formed. The concentration of titanium oxide pigments therein tends to increase, and techniques for improving visual whiteness have become even more important.

Conventionally, several techniques for improving the whiteness of a resin layer containing titanium oxide on the image forming side of a resin-coated paper-type photographic support have been known.

U.S. Pat. No. 3,501,298 discloses that in addition to titanium oxide in a resin layer, ultra-blue inorganic pigments such as ultramarine blue, cobalt blue and red inorganic pigment cobalt oxide (Ferro Colors Corp.)
Raspberry V-6260, quinacridone red, a reddish organic pigment, and Uvitex OB (CIBA
It is known to include a fluorescent whitening agent having a bis (alkyl-substituted benzoxazolyl) thiophene structure substituted by GEIGY (trade name of GEIGY). Japanese Patent Application Laid-Open No. 53-19021 contains cosmetic ultramarine, which is called blue inorganic pigment, ultramarine blue, and red inorganic pigments, Daiichi Pink DP-1 and Daiichi Violet DV-1 (all manufactured by Daiichi Kasei Kogyo). It is disclosed. JP-A-56-51336 discloses that a fluorescent whitening agent having a bis (alkyl-substituted benzoxazolyl) naphthalene structure is contained in a resin layer. JP-A-61-75341 discloses a technique for incorporating a quinacridone reddish organic pigment into a resin.

However, each of these techniques has drawbacks.

That is, an inorganic or organic coloring pigment is contained in the resin on the image forming side of the resin-coated paper type photographic support,
As for the technology of neutralizing the tendency to take on the yellow tint due to the titanium oxide pigment contained in the high concentration and improving the visual whiteness, since it is colored after all to make it look white, the brightness decreases, It is a problem because clear white is not obtained.

In the case of inorganic color pigments, they generally tend to contain a large amount of water, and bring a large amount of water into the resin composition. When the water content in the resin composition is large, there is a problem that cracks in the resin film due to blowing of water vapor tend to easily occur during melt extrusion coating. Furthermore, ultramarine and cobalt-based inorganic coloring pigments deteriorate the heat resistance of the resin due to its chemical activity, and the degraded resin composition adheres and accumulates at the opening of the die lip of the extrusion coating machine, forming an icicle. Foster a growing trend. When such icicle-like deposits are generated, streak-like scratches are generated on the resin film, and there is a problem that the commercial value of the resin-coated paper-type photographic support is significantly impaired. On the other hand, bis (alkyl-substituted benzoxazolyl)
With respect to the technique of adding a known optical brightener such as thiophene to a resin composition to improve whiteness, the optical brightener tends to bleed out of the resin. Not only is there a problem with the stability of the color tone, but there is also a problem with the adhesion to the photographic emulsion layer. Further, when a fluorescent whitening agent is contained in the resin composition to make the resin composition white, the stability of the whiteness is poor, the weather resistance such as so-called light fastness and dark fading is poor, and it gradually becomes yellow with time. It turned out that there was a problem. Further, in the case of a resin-coated paper in which a fluorescent whitening agent having a bis (alkyl-substituted benzoxazolyl) thiophene structure represented by Ubitex OB is added to a resin layer, a photographic material using the coated paper as a support is used. When processed with an acidic hardening fixer, there is a problem that the whiteness is improved rather than the whiteness is improved.

[Problems to be solved by the invention]

Accordingly, an object of the present invention is to eliminate the yellow tint caused by titanium oxide contained in a high concentration in a resin, to have no visually coloring, and therefore to provide a clear, white, resin-coated paper type photographic support having high brightness. It is to provide. Another object of the invention is
No resin cracking, no problem with heat resistance, no bleed-out phenomenon, good weather resistance and therefore good preservation of whiteness, furthermore, no nuisance by photographic processing solution, high brightness and clear white An object of the present invention is to provide a resin-coated paper type photographic support. Another object of the present invention is, in particular, sharpness,
An object of the present invention is to provide a clear and white resin-coated paper type photographic support having good resolution and high brightness.

[Means and actions for solving the problems]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, in a photographic support in which both sides of a base paper are coated with a polyolefin resin, at least an oxidized layer is formed in a resin layer on a surface on which an image is formed. It has been found that the object of the present invention can be achieved by adding titanium and a fluorescent agent represented by the following structural formula [I].

(In the formula, R ₁ , R ₂ , R ₃ and R ₄ represent hydrogen or an organic residue.) Further, an object of the present invention is to provide a resin-coated paper type photographic support on which an image is formed on a resin. This can be achieved remarkably by incorporating at least a rutile-type titanium oxide pigment and a fluorescent agent represented by the structural formula [I] in the layer. That is, the resin-coated paper-type photographic support using the rutile-type titanium oxide pigment has sharpness and a higher resolving power than when the anatase-type titanium oxide is used, but has a strong yellow tint due to the titanium oxide and is white. It was extremely difficult to obtain an excellent photographic support. However, according to the present invention,
It is possible to provide a clear and white resin-coated paper-type photographic support having high sharpness and resolution and without any of the above-mentioned problems and having high brightness.

As the titanium oxide pigment used in the practice of the present invention,
Rutile type or anatase type may be used, but from the viewpoint of sharpness and resolution, rutile type titanium oxide pigment is preferable. As described in JP-B-56-5987, a rutile-type titanium oxide pigment and an anatase-type titanium oxide pigment can be used in combination.

Further, as the titanium oxide pigment which is advantageously used in the practice of the present invention, those coated with various inorganic oxides or hydrated inorganic oxides, for example, JP-B-44-2564, JP-A-52-35625, JP-B-63-11655 or those exemplified or coated with various organic compounds, for example, JP-A-55-10865, JP-A-55-113040, JP-A-57-3
No. 5855, JP-A-57-36156, JP-B-61-26652, JP-A-58-75151, JP-A-58-58542, JP-A-58-17433
No., JP-B-59-37304, JP-A-62-25753, JP-A-62-25753
-141544, JP-A-62-148946, JP-A-62-161147
And those described or exemplified in British Patent No. 1,164,849, and other suitable photographic titanium oxide pigments, for example,
57-32442, JP-A-57-46818, JP-A-58-220140
No., JP-A-59-1544, JP-A-59-121329, JP-A-58
Various types such as those described or exemplified in JP-A-215344 and JP-A-62-103635 can be used.

However, as the titanium dioxide pigment, the polyolefin resin layer contains a rutile type titanium dioxide pigment surface-treated with 0.2% by weight to 1.2% by weight (calculated in the form of Al ₂ O ₃ ) based on the titanium dioxide. By doing so, the object of the present invention can be more remarkably achieved.
That is, if the amount of surface treatment with hydrous aluminum hydroxide is less than 0.2% by weight, the resin layer containing the titanium dioxide pigment and the fluorescent agent of the present invention is greatly deteriorated by light and is not practical.

On the other hand, the surface treatment amount with hydrous aluminum hydroxide was 1.2
When the amount is more than 10% by weight, icicle-like deposits (hereinafter referred to as die lip stains) tend to occur at the opening of the extruder die lip during the melt extrusion coating of the polyolefin resin composition containing the titanium dioxide pigment. In addition, it has been found that when melt-extrusion coating of the resin composition containing the titanium dioxide pigment and the fluorescent agent of the present invention, the tendency of die lip stains to occur is further increased. However, in the most preferred embodiment of the present invention, 0.2% to 1.2% by weight (calculated in the form of Al ₂ O _{3) based on} titanium dioxide in the polyolefin resin layer on the image forming side of the resin-coated paper type photographic support. do it)
By containing the rutile-type titanium dioxide pigment surface-treated with hydrous aluminum hydroxide and the fluorescent agent of the present invention, the sharpness of the printed image is high, the brightness is high, the appearance is white, and the weather resistance of the resin layer is high. In addition, it has been found that the production of a photographic support has very little die lip stains, and therefore an excellent photographic support having good surface quality can be provided.

The content of the titanium oxide pigment in the resin composition is 5%.
If it is less than 10% by weight, sharpness as a photographic support,
A problem arises in that the resolving power is lowered. If it exceeds 40% by weight, the fluidity is lowered, which is not preferred. The range is preferably 9 to 30% by weight, and particularly preferably 9 to 25% by weight. As a method of incorporating the titanium oxide pigment into the resin composition of the photographic support, a so-called masterbatch in which titanium dioxide is previously contained at a certain concentration in a polyolefin is prepared, and they are diluted to a desired ratio with a diluting resin. It is customary to use a mixture, or to prepare and use a so-called compound in which a titanium dioxide pigment is initially contained in a polyolefin in a desired composition ratio. Usually, a Banbury mixer, a kneader, a kneading extruder, a two-roll kneading machine, a three-roll kneading machine, and the like are used for preparing these master batches and compounds, but a Banbury mixer and a kneading extruder are advantageously used. Can be These kneaders may be used in combination of two or more.

Specific examples of the master batch production method include, for example, JP-A-60-11841, JP-A-60-75832, and JP-A-60-181131.
Or the method described or exemplified in the above section.

Specific examples of the fluorescent agent represented by the structural formula [I] used in the embodiment of the present invention include those represented by the following formula. It can also be used in a mixture thereof.

These fluorescent agents are produced by condensing stilbene-4,4'-dicarboxylic acid with 1-amino-2-hydroxy-4and / or 5-substituted benzene as described in JP-A-48-6080 or as exemplified. . Among these fluorescent agents, structural formulas [III] to [VI] are preferable in terms of bleed-out resistance and weather resistance, and structural formulas [IV] to [VI] are particularly preferable. As the content of these fluorescent agents in the resin composition, from a comprehensive point such as whiteness, resin processability, heat resistance, bleed-out resistance, weather resistance, 0.1 mg / m ² ~ 50 mg / m a ^second range, particularly preferably in the range of ^{0.5mg / m 2 ~10mg / m 2} .

Further, as a method of incorporating the fluorescent agent in the resin composition of the present invention, a titanium oxide pigment, a fluorescent agent, a polyolefin resin, dispersing the titanium oxide pigment, when manufacturing a master batch or a compound of the titanium oxide pigment. A masterbatch or compound comprising an agent, for example, a metal salt of a resin acid, can be prepared and included in the resin composition. Also, a master batch of a fluorescent agent having a softening point lower than that of the main polyolefin resin and being solid at ordinary temperature and / or a dispersant such as a fluorescent agent premixed with a fatty acid metal salt and dispersed in the main polyolefin. Can be prepared and included in the resin composition.

On the other hand, JP-A-48-6080 discloses an aqueous dispersion of the fluorescent agent represented by the structural formula [I], but this dispersion cannot be contained in a polyolefin resin, and Even if an effect is obtained by adding it to the undercoat layer of the support for use, there is a problem that the adhesiveness with the photographic constituent layer is deteriorated and the photographic properties are adversely affected. It has been found that the use of the fluorescent agent represented by the structural formula [I] can overcome many problems and achieve the object of the present invention.

Pulp constituting the base paper used in the practice of the present invention is described in JP-A-58-37642, JP-A-60-67940,
It is advantageous to use appropriately selected natural pulp as described or exemplified in JP-A-60-69649 and JP-A-61-35442, but if necessary, synthetic pulp other than natural pulp, synthetic pulp Fibers may be used. Natural pulp was subjected to normal bleaching treatment of chlorine, hypochlorite, chlorine dioxide bleaching, and alcal extraction or alkali treatment and, if necessary, oxidative bleaching treatment with hydrogen peroxide, oxygen, etc., and combinations thereof. Wood pulp of softwood pulp, hardwood pulp, softwood mixed pulp is advantageously used, and kraft pulp, sulfite pulp,
Various materials such as soda pulp can be used.

The base paper used in the practice of the present invention can contain various sizing agents, polymer compounds, and additives during preparation of the stock slurry.

Examples of the sizing agent advantageously contained in the base paper used in the practice of the present invention include fatty acid metal salts and / or fatty acids, alkyl ketene dimers, alkenyl or alkyl succinic anhydrides, and epoxy resins described in JP-A-54-147211. Higher fatty acid amides and the organic fluoro compounds described in JP-A-56-109343.

The sizing agent advantageously contained in the base paper used in the practice of the present invention includes a fatty acid metal salt or / and / or a metal salt fixed to pulp with a water-soluble aluminum salt such as aluminum chloride, bansulfate, and polyaluminum chloride. Alkyl ketene dimer or a combination sizing agent of an alkyl ketene dimer and an epoxidized higher fatty acid amide in a mode in which a fatty acid or a water-soluble aluminum salt is fixed to pulp with or without a water-soluble aluminum salt can be used. The fatty acid metal salt and / or the fatty acid preferably has 12 to 22 carbon atoms, and the amount thereof is preferably in the range of 0.5 to 4.0% by weight based on the absolute dry weight of the pulp. The amount of the water-soluble aluminum salt to be added as needed is 1/20 based on the solid weight of the sizing agent.
The range of 4 to 4/1 is particularly preferable in the range of 1/10 to 1/1. As the alkyl ketene dimer, one having an alkyl group having 8 to 30 carbon atoms, preferably 12 to 18 carbon atoms is preferable. Alkyl ketene dimer is usually commercially available as an emulsion thereof, and specific examples include Acopel 360XC manufactured by Dick Hercules Co., Ltd. The amount of the alkyl ketene dimer is 0.
A range of 2 to 4.0% by weight is preferred.

Polymeric compounds which are advantageously incorporated into the base paper used in the practice of the present invention during preparation of the stock slurry include cationic wet paper strength enhancers and cationic, anionic or amphoteric paper strength enhancers. As the cationic wet paper strength enhancer, a polyamine polyamide epichlorohydrin resin is preferable, and the amount of the resin added is based on the pulp dry weight.
The range of 0.05 to 4.0% by weight, particularly the range of 0.15 to 1.5% by weight is preferred. Specific examples thereof include Sponge 557H, Sponge S-25, and Epinox P-130 manufactured by Dick Hercules Co., Ltd.

Examples of the cationic, anionic or amphoteric paper strength enhancer include cationized starch described or exemplified in Japanese Patent Publication No. 60-17103, cationic polyvinyl alcohol described or exemplified in Japanese Patent Application No. 62-49699, and Showa 57-1854
No. 32, cationic polyacrylamide described or exemplified in JP-A-57-197539, JP-B-62-23119, JP-B-6-19769
Anionic polyacrylamide described or exemplified in 2-31118, amphoteric polyacrylamide described or exemplified in JP-B-61-37613, JP-A-59-31949, JP-A-59-31949
And plant galactomannans described or exemplified in No. 125731. Their addition amount is in the range of 0.05 to 8% by weight, especially 0.15 to
A range of 4% by weight is preferred.

The base paper used in the practice of the present invention may contain various additives during preparation of the stock slurry. As filler, clay, kaolin, calcium carbonate,
Barium sulfate, magnesium silicate, titanium oxide, etc.
As pH adjusters, caustic soda, sodium carbonate, etc., coloring pigments, coloring dyes, and fluorescent brightening agents, JP-A-54-147033.
And those described or exemplified in Japanese Patent Application Nos. 62-37555 and 63-96516 can be appropriately combined.

Various water-soluble polymers, antistatic agents, and additives can be contained in the base paper used in the practice of the present invention by spraying or tub size press. Examples of the water-soluble polymer include starch-based polymers, polyvinyl alcohol-based polymers, gelatin-based polymers, polyacrylamide-based polymers, and cellulose-based polymers described or exemplified in Japanese Patent Application No. 63-96516. No. 96516 or exemplified by alkali metal salts such as sodium chloride and potassium chloride, alkaline earth metal salts such as calcium chloride and barium chloride, colloidal metal oxides such as colloidal silica, and JP-A-58-82242. The organic antistatic agent described or exemplified, such as latex and emulsions, such as petroleum resin emulsion, styrene-acrylic acid-acrylic acid stem copolymer, styrene-acrylic acid-butadiene copolymer, ethylene-
Latexes such as vinyl acetate copolymers, styrene-maleic acid-acrylate copolymers, as pigments, clay, kaolin, talc, barium sulfate, titanium oxide, etc., as PH regulators, hydrochloric acid, phosphoric acid, citric acid, It is advantageous to incorporate an appropriate combination of additives such as caustic soda and sodium carbonate, and the above-mentioned coloring pigments, coloring dyes, fluorescent whitening agents and the like.

For the production of the base paper used in the examples of the present invention, a commonly used paper machine such as a fourdrinier paper machine or a round net paper machine is used, but JP-A-58-37642, JP-A-61-260240, It is advantageous to employ a suitable papermaking method as described or exemplified in JP-A-61-284762. There is no particular limitation on the thickness of the base paper.
No. 58-37642, is preferably one obtained by calendering the base paper are described or exemplified in JP-A-60-126397, the basis weight preferably from ^{40g / m 2 ~250g / m 2} .

Examples of the polyolefin resin used in the practice of the present invention include low-density polyethylene, high-density polyethylene, polypropylene, polybutene, olefin homopolymers such as polypentene, and copolymers composed of two or more olefins such as ethylene-propylene copolymer. And mixtures thereof, and those having various densities and melt viscosity indices (melt index) can be used alone or as a mixture thereof. When the resin has a multilayer structure, the resin of the outermost layer is, for example, one having a melt index (hereinafter abbreviated as MI) of 5 to 20, and the resin of the lower layer is, for example, 2 to 10
Resins of other properties can be used, such as the use of a resin.

In the resin layer on the image forming side of the photographic support in the present invention, 9 to 20% by weight of a titanium dioxide pigment is contained. In the case of a multi-layer resin-coated paper, the lower resin layer contains May or may not contain a titanium dioxide pigment. In the polyolefin resin, white pigments such as zinc oxide, talc and calcium carbonate, fatty acid amides such as stearic acid amide and arachidic acid amide, zinc stearate, calcium stearate, aluminum stearate, magnesium stearate, zirconium octylate Fatty acid metal salts such as sodium palmitate, calcium palmitate, sodium laurate, tetrakis [methylene-3 (3,5-di-tert.
-Butyl-4-hydroxyphenyl) propionate]
Antioxidants such as methane and 2,6-di-tert-butyl-4-methylphenol; blue pigments and dyes such as cobalt blue, navy blue, ultramarine, cerulean blue and phthalocyanine blue; cobalt violet, fast violet, and manganese purple It is preferable that various additives such as ultraviolet absorbers such as magenta pigments and dyes, tinuvin 320, tinuvin 326 and tinuvin 328 (trade names of Ciba-Geigy) are appropriately combined and added.

The photographic support produced according to the present invention is produced by a so-called extrusion coating method in which a heated and melted polyolefin resin is cast on a running base paper, and both surfaces thereof are covered with the resin. At that time, in the case of a multilayer structure, the outermost resin layer on the front side of the photographic support and the inner resin layer are sequentially formed.
It is preferred to use a so-called tandem extrusion system, preferably a continuous extrusion coating, or a so-called co-extrusion coating system, in which the outermost resin layer and the inner resin layer are simultaneously multilayer-extruded. Further, it is preferable to perform an activation treatment such as a corona discharge treatment or a flame treatment on the base paper before coating the base paper with the polyolefin resin. The emulsion-side surface of the photographic support has a glossy surface or Japanese Patent Application Laid-Open No. 55-26507, which does not affect the gloss of the photographic paper surface when photographic paper is used.
No. surface or matte surface, silk surface etc.,
The back surface is usually a matte surface, and activation treatment such as corona discharge treatment or flame treatment can be applied to the front surface or both the front and back surfaces as required. Further, after the activation treatment,
The undercoating processing as described in No. 84643 can be performed. Also, as the thickness of the resin layer on the front and back of the resin-coated paper,
Although not subject to any particular limitation, it is generally advantageous to apply extrusion coating to a thickness of about 10 to 50 μm.

Various types of back coat layers can be applied to the photographic support of the present invention for the purpose of preventing static charge and curling. In addition, the back coat layer includes
No., JP-B-57-9059, JP-B-57-53940, JP-B-58
-56859, JP-A-59-214849, JP-A-58-184144 and the like or inorganic antistatic agents, organic antistatic agents, hydrophilic binders, latexes, curing agents, pigments, surfactants, etc. Can be included in an appropriate combination.

The photographic support in the present invention is coated with various photographic constituent layers and is used for color photographic printing paper, black-and-white photographic printing paper, typesetting printing paper, copying photographic paper, reversal photographic material, silver salt diffusion transfer. It can be used for various purposes such as negative and positive, and printing materials. For example, silver chloride, silver bromide, silver chlorobromide,
A silver iodobromide or silver chloroiodobromide emulsion layer can be provided. The silver halide photographic emulsion layer may contain a color coupler to provide a multilayer silver halide constituting layer. Further, a silver salt diffusion transfer image-receiving layer can be provided by incorporating a physical development nucleus. As binders for those photographic constituent layers, other than ordinary gelatin, polyvinylpyrrolidone,
A hydrophilic polymer substance such as polyvinyl alcohol and a polysaccharide sulfate compound can be used. Further, the above-mentioned photographic constituent layer can contain various additives. For example, as sensitizing dyes, cyanine dyes, merocyanine dyes, etc., as chemical sensitizers, water-soluble gold compounds, sulfur compounds, etc., as antifoggants or stabilizers, hydroxy-triazolopyrimidine compounds, mercapto-heterocyclic compounds, etc. , As hardeners, formalin, vinyl sulfone compounds, aziridine compounds, etc.
As a coating aid, benzene sulfonate, sulfosuccinate, etc .; as a stain inhibitor, a dialkyl hydroquinone compound, etc., in addition to a fluorescent whitening agent, a sharpness improving dye, an antistatic agent, a pH regulator, a fogging agent, Further, a water-soluble iridium, a water-soluble rhodium compound or the like can be incorporated as appropriate during the formation and dispersion of silver halide.

The silver halide photographic material according to the present invention may be exposed, developed, and stopped in accordance with the photographic material, as described in "Photosensitive Materials and Handling Methods" (Kyoritsu Shuppan, Goro Miyamoto, Photographic Technology Course 2). , Fixing, bleaching, stabilization, etc. are performed. In particular, multi-layer silver halide color photographic materials which are subjected to one-bath bleach-fixing after color development are CD-III and CD-IV (the above two compounds are Kodak It can be processed with a color developing solution of any principal agent such as a trade name of a company) or droxychrome (a trade name of May and Baker). A developing solution containing such a base may contain a development accelerator such as benzyl alcohol, thallium salt, or phenidone. Further, the treatment can be carried out with a developer substantially free of benzyl alcohol. A useful one-bath bleach-fix solution is a metal salt of aminopolycarboxylic acid (for example, a ferric complex salt such as ethylenediaminetetraacetic acid or propylenediaminetetraacetic acid).
It is a bath solution, and as a fixing agent, sodium thiosulfate, ammonium thiosulfate and the like are useful. Various additives can be contained in such a one-bath bleach-fix solution. For example, a desilvering accelerator (eg, a mercaptocarboxylic acid described in U.S. Pat. No. 3,512,979, a mercapto-heterocyclic compound described in Bengui Patent 682,426, etc.), a stain inhibitor, a pH adjusting or pH buffering agent, a hardening film Various compounds such as agents (eg, magnesium sulfate, aluminum sulfate, potassium alum, etc.) and surfactants can be contained in combination. Also, such single bath bleach-fix solutions can be used at various pHs, but a useful pH range is pH 6.0 to 8.0.

〔Example〕

Next, examples will be described in order to more specifically describe the present invention.

Example 1 A mixed stock of 50 parts by weight of hardwood bleached kraft pulp and 50 parts by weight of softwood sulphite pulp was beaten to 310 ml of Canadian Standard Freeness, and further 100 parts by weight, 3 parts by weight of cationized starch, and anionized 0.2 parts by weight of polyacrylamide, 0.4 parts by weight of an alkyl ketene dimer emulsion (as ketene dimer), and 0.4 parts by weight of a polyamide polyamine epichlorohydrin resin are added.
Paper having a basis weight of 160 g / m ² was produced. The obtained wet paper is dried at 110 ° C., and subsequently carboxy-modified polyvinyl alcohol 3
Impregnating solution containing 25 parts by weight, an optical brightener 0.05 parts by weight, a blue dye 0.002 parts by weight, citric acid 0.2 parts by weight and water 97 parts by weight, impregnated with 25 g / m ² , dried with hot air at 110 ° C., and further subjected to linear pressure. 90k
After calendering at g / cm, both surfaces were subjected to a corona discharge treatment to produce a base paper of a resin-coated paper for photography.

Next, high density polyethylene (density 0.96g /
cm ³ , MI = 5) and low-density polyethylene (density 0.92 g / cm ³ ,
A 1: 1 mixture of MI = 5) was coated at a resin temperature of 330 ° C. using a melt extrusion coater to a thickness of 30 μm. Then, after thoroughly mixing the resin compositions described in Table 1 on the surface of the base paper,
Using a screw extruder with an extrusion diameter of 65 mm and a melt extruder having a T die of 750 mm width, the resin was coated at a resin temperature of 320 ° C. to a thickness of 30 μm to produce photographic supports containing titanium oxide pigment and the like, respectively. . At that time, the surface resin layer containing a titanium oxide pigment or the like was processed into a flat glossy surface, and the back resin layer was processed into a matte surface such as paper. The numerical values in the table represent parts by weight.

Note 1: 50 parts by weight of rutile titanium oxide, zinc stearate 2.
5 parts by weight Master batch consisting of 47.5 parts by weight of polyethylene with a density of 0.918 MI9.

Note 2: A masterbatch consisting of 50 parts by weight of rutile titanium oxide, 1.25 parts by weight of ultramarine blue, 2.5 parts by weight of zinc stearate, and 46.25 parts by weight of polyethylene having a density of 0.918 MI9.

Note 3: The resin used in the lower column is polyethylene with a density of 0.918 MI9.

Note 4: Polyethylene with a density of 0.92 MI5.

Note 5: Cobalt Blue # 3 manufactured by The Shepard Color Company
10% by weight and 0.5% by weight of zinc stearate.

Note 6: Chromophthal Blue ASR (Ciba Geigy) has the following structure Contains 0.1% by weight of Chromophtal Blue A3R and 0.1% by weight of low molecular weight polyethylene.

Note 7: No other additives are included.

* 8: 0.4% by weight of fluorescent agent and 0.4% by weight of low molecular weight polyethylene
including.

Note 9: 0.1% by weight of fluorescent agent and 0.1% by weight of low molecular weight polyethylene
including. The same applies to the following two fluorescent agents.

A part of each of the obtained photographic supports was finished on black and white photographic paper. The remaining part was coated with the same amount of gelatin as contained in the black and white photographic paper.

Evaluation method of whitening effect: The color tone of a sample coated with gelatin was evaluated. The evaluation criteria are white → ○, yellow →→, yellow → ×.

Processing solution resistance evaluation method: A black-and-white photographic paper was treated with an acidic hardening solution (Kodak Formulation F-5) at 20 ° C. for 5 minutes and washed with water. The surface tone was compared to an untreated gelatin coated sample. No change in evaluation criteria → ○, yellowing → △, yellowing →
×.

Evaluation method for dark discoloration: samples coated with gelatin in a dark place
The mixture was heated to 50 ° C and stored for one week, and the change in color tone before and after that was examined. The criteria are the same as in the previous section.

Sun fading evaluation method: A sample coated with gelatin was exposed to sunlight for two months, and the change in color tone before and after that was examined. The criteria are the same as in the previous section.

Bleed-out property evaluation method: A resin surface having a rough surface of non-fluorescent resin-coated paper was superimposed on the front side resin surface of an uncoated sample, and stored under a load of 50 g / cm ² at 50 ° C. for 3 days. The non-fluorescent resin-coated paper that was in contact with the sample resin surface was irradiated with an ultraviolet lamp and observed. Evaluation criteria do not shine at all →
、, a small amount of the fluorescent agent was transferred and glowed → △, most of the fluorescent agent was transferred and glowed entirely → ×. The results are shown in Table 2.

Samples that have been color corrected with color pigments have low brightness,
Dullness is felt. The sample is clear white,
There are problems with processing solution resistance, storage stability, and bleed-out properties.
Samples have bleed-out problems. In addition, icicle-like deposits were generated at the die lip openings during sample production.

Example 2 A photographic support was produced by replacing Table 1 in Example 1 with Table 3. The numerical values in the table are parts by weight.

Note 10: 50 parts by weight of rutile type titanium oxide with alumina coverage of 0.5% titanium oxide (as Al ₂ O ₃ ), zinc stearate
2.5 parts by weight Masterbatch consisting of 47.5 parts by weight of polyethylene having a density of 0.918 and MI 9

Note 11: Master batch consisting of 50 parts by weight of titanium oxide, 1.25 parts by weight of ultramarine blue, 2.5 parts by weight of zinc stearate, and 46.25 parts by weight of polyethylene as above.

Note 12: Polyethylene with a density of 0.92 MI5.

Note 13: Polyethylene with a density of 0.96 MI7.

* 14: Daiichi Kasei Kogyo Co., Ltd. cosmetic ultramarine Daiichi Pink DP
-3 1 part by weight, density 0.918, MI 9 polyethylene 99
Master batch consisting of parts by weight.

Note 15: Same as Note 9.

Note 16: Same as Note 6.

Note 17: A resin composition comprising 0.1 part by weight of Hostapam Pink E (quinacridone magenta pigment) manufactured by Hoechst AG, 0.1 part by weight of low molecular weight wax, and 99.8 parts by weight of polyethylene having a density of 0.918 MI9.

A part of each of the obtained photographic supports has a blue-sensitive emulsion layer and an intermediate layer containing a yellow-color-forming coupler, a green-sensitive emulsion layer containing a magenta-color-forming coupler, an ultraviolet-absorbing layer containing an ultraviolet absorber, and a cyan-color-forming layer. A color photographic paper was manufactured by sequentially coating a red-sensitive emulsion layer containing a coupler and a protective layer. The remaining part was coated with the same amount of gelatin as used for the color photographic paper. Evaluation was performed in the same manner as in Example 1 except that the following processing was performed on unexposed color photographic paper in place of the acid hardening fixer processing in Example 1. The results are shown in Table 4. Processing: color development 3 minutes 30 seconds, bleach-fix 1 minute 30 seconds, water washing 3 minutes 30 seconds (33 ° C) Color developer sodium carbonate (monohydrate) 46.0 g anhydrous sodium sulfite 2.0 g potassium bromide 0.5 g CD-III 4.5 g Sodium hexametaphosphate 0.5 g Hydroxylamine sulfate 2.0 g Optical brightener 0.5 g Benzyl alcohol 12 cc Diethylene glycol 10 cc Adjust the total amount to 1 with water and adjust to pH 10.2 with sodium hydroxide.

Bleaching-fixing solution Ferric complex salt of ethylenediaminetetraacetic acid 56 g Disodium salt of ethylenediaminetetraacetic acid 2 g Ammonium thiosulfate 60 g Sodium sulfite anhydride 20 g Sodium acid sulfite 5 g Disodium phosphate 12 g Adjust the total amount to 1 with water.

Example 3 The results in Table 6 were obtained in exactly the same manner as in Example 2 except that Table 5 was used instead of Table 3 in Example 2.

 The numerical values in Table 5 represent parts by weight.

As seen in Table 6, the effect is insufficient when the amount of the fluorescent agent is small, and the effect is worse when the amount is too large.

Example 4 Example 4 was carried out in exactly the same manner as in Example 1 except that anatase type titanium oxide was used instead of rutile type titanium oxide.

The same results as in Example 1 were obtained except that the color was not so yellow even without the fluorescent agent, and that the use of the fluorescent agent resulted in a sharper white.

Example 5 The fluorescent agent of Example 2 was replaced with No. IV to No. V, No. VI
And the same results were obtained as in Example 2.

Example 6 Except for using the titanium dioxide pigments described in Table 7 in place of the titanium dioxide pigments used in Notes 1 and 2 of Example 1, no ultramarine was contained as in Notes 1 and 2 of Example 1. A masterbatch and a masterbatch containing ultramarine were created.

Then, instead of the resin composition used in Example 1, 20.8 parts by weight of the master batch containing no ultramarine prepared as described above, 5.2 parts by weight of the master batch containing ultramarine, described in Sample No. 9 of Example 1 0.1 of the No. IV fluorescent agent described in the same text
A resin-coated paper-type photographic support was produced in the same manner as in Example 1 except that 10 parts by weight of a resin containing 100% by weight and 64 parts by weight of the same diluent resin as in Example 1 were used.

The obtained results are shown in Table 7. The sharpness, the number of dilip stains and the light fastness of the printed image in the table were evaluated as follows.

(Evaluation of Sharpness of Printed Image) In order to measure the sharpness of a printed image, a color photographic printing paper using the above-described photographic resin-coated paper as a support was manufactured. First, a back coat layer composed of a colloidal silica: styrene-acrylic latex = 1: 1 composition as a dry weight component after corona discharge treatment on the back side of a photographic resin-coated paper.
0.4 g / m ² was applied. Next, a corona discharge-treated blue-sensitive emulsion layer containing a yellow-colored coupler, an intermediate layer containing a color-mixing inhibitor, and a green-sensitive emulsion layer containing a magenta-colored coupler after the corona discharge treatment on the resin surface of the photographic resin-coated paper containing the titanium dioxide pigment. , ultraviolet absorbing layer containing an ultraviolet absorber, silver chlorobromide each color sensitive emulsion layer to obtain a color photographic paper by providing a red-sensitive emulsion layer and the protective layer is equivalent to 0.6 g / m ² with silver nitrate containing cyan color coupler Including
Further, in addition to gelatin necessary for formation, dispersion and film formation of silver halide, it also contains an appropriate amount of antifoggant, sensitizing dye, coating aid, hardener, thickener, and appropriate amount of filter dye.

A resolving power chart was adhered to the obtained color photographic printing paper, exposed to green light, and subjected to color development to obtain a test sheet. This test sheet was measured with a microdensitometer, calculated using a personal computer according to a conventional method, and used as a CTF (Contrast
Transfer Function (contrast transfer function) was determined, and the sharpness of the printed image of the resin-coated paper for photography was measured. The CTF indicates that the larger the value, the higher the sharpness of the print image.

(Evaluation of die lip stain) The number of die lip stains 2 hours after the start of bath melt extrusion in each sample was counted. At that time, the total number of die lip stains generated on the front side and the rear side of the die was counted.

(Evaluation of light resistance) Suga test machine made fade meter (FAL-25X-HCL type)
After irradiation for 80 hours with a Macbeth densitometer (RD-519)
3) shows the Y concentration measured by the above (type). The lower the value, the better the light resistance.

As can be seen from Table 7, when a titanium dioxide pigment surface-treated with hydrous alumina was used in combination with a fluorescent agent (Sample No. 2
9) It can be seen that the generation of die lip stain is promoted as compared with the case of the sample (Sample No. 23) which does not contain the fluorescent agent and is not the present invention. However, a rutile titanium dioxide pigment surface-treated with 0.2 to 1.2% by weight (calculated in the form of Al ₂ O ₃ ) based on titanium dioxide, which is a preferred embodiment of the present invention, and a fluorescent agent are used. When used together (Sample No. 26
Nos. 28 to 28) show that there is no generation of die lip stain, and therefore the surface support is good, the sharpness of the printed image is high, and the light resistance is excellent, and thus the support is excellent.

〔The invention's effect〕

When the present invention is carried out, a photographic support having a clear whiteness can be obtained without any trouble.

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-52-29215 (JP, A) JP-A-50-66234 (JP, A) JP-A-51-6531 (JP, A) JP-A-63-63 239444 (JP, A) JP-A-59-166949 (JP, A) Japanese Translation of PCT Application No. Hei 2-502761 (JP, A)

Claims (4)

(57) [Claims] In a resin-coated paper-type photographic support in which paper is used as a substrate and both surfaces of which are coated with a polyolefin resin, the resin layer on the surface on which an image is formed has at least (A) a titanium oxide pigment and (B) A photographic support comprising at least a composition comprising a fluorescent agent represented by the following structural formula [I] and a low molecular weight polyolefin. (In the formula, R ₁ , R ₂ , R ₃ and R ₄ represent hydrogen or an organic residue.) 2. The fluorescent agent according to claim ₁ , wherein R ₁ , R ₂ , R ₃
And at least one of R ₄ is an alkyl group having 12 or less carbon atoms, photographic support according to claim 1, wherein in which the remainder is represented by an alkyl group having 12 or less of hydrogen or carbon. 3. The photographic support according to claim 1, wherein the titanium oxide is rutile type titanium oxide. 4. The rutile-type titanium dioxide pigment is surface-treated with 0.2% to 1.2% by weight (calculated in the form of Al ₂ O ₃ ) of hydrous aluminum hydroxide based on titanium dioxide. 3. The photographic support according to 3.