JP2777210B2 - 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.

From another viewpoint, the present invention relates to a resin-coated paper-type photographic support containing a highly dispersed titanium oxide in a high concentration in a resin layer on which an image is formed.

Further, from another viewpoint, the present invention relates to a resin-coated paper-type photographic support which is coated with a resin composition for preventing a stain on a die lip portion generated during extrusion processing and has no streak-like surface damage.

From still another viewpoint, the present invention relates to a resin-coated paper-type photographic support having a good surface property coated with a resin composition that suppresses the occurrence of fine avatar-like scratches during resin coating at high speed. It is.

(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.

The polyolefin resin layer on the front side of the waterproof support, on which the image is formed, contains a titanium oxide pigment due to image sharpness and other requirements mainly due to photographic performance, but addition of titanium oxide to the resin layer Three major problems have arisen in relation to.

The first problem is that the titanium oxide pigment is not sufficiently dispersed in the polyolefin.

Because the dispersion of titanium oxide is not perfect, when using photographic paper, the resolution is insufficient.
-Titanium oxide whose particle surface is treated with alcoholamine as described in JP-B-26650, Japanese Patent Publication No. 58-43
No. 734, JP-A-58-14830, JP-A-17433,
Japanese Patent Nos. 58542 and 75151 disclose a method of treating the particle surface with a di- to tetrahydric alcohol.

However, when the proposed method is used, at the time of resin coating, when a resin composition is melt-extruded from a slit die into a film, a needle-like or icicle-like attachment or dirt (hereinafter simply referred to as dilip dirt) is formed at the tip of the die lip. This die lip stain tends to grow steadily as the melt extrusion time elapses.

When this die lip stain occurs during melt extrusion coating, streaks are generated in the vertical direction on the surface of the photographic support manufactured as it is, or streaky unevenness due to uneven coating amount occurs. In some cases, dirt adheres to the film and is applied, and foreign matter appears. As a result, the surface quality of the produced polyolefin resin-coated paper is significantly impaired, making it unsuitable as a photographic support requiring excellent surface quality and having no commercial value. Is also meaningless.

As a second problem, since the titanium oxide pigment has a yellow tint, the whiteness of a white background portion of a photographic image becomes insufficient as it is.

Especially in the case of color printing 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 of color images and black-and-white images has increased, and the resin-coated paper type photographic support has a resin layer on the image forming side. The concentration of titanium oxide pigments tends to increase, and techniques for improving visual whiteness have become 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, in addition to titanium oxide in a resin layer, ultramarine blue, cobalt blue, which is a bluish inorganic pigment,
Cobalt oxide phosphate, a reddish inorganic pigment (Ferro Colors C
orp Raspberry V-6260), containing quinacridone red, a reddish organic pigment, and Uvitex OB (C
It is known to include a fluorescent whitening agent having a bis (alkyl-substituted benzoxazolyl) thiophene structure represented by IBAGEIGY (trade name). Japanese Patent Application Laid-Open No. 53-19021 contains ultramarine blue, which is a bluish inorganic pigment, and cosmetic ultramarine blue, which is a reddish inorganic pigment, Daiichi Pink DP-1 and Daiichi Violet DV-1 (both manufactured by Daiichi Kasei Kogyo Kogyo). Is disclosed. In addition, Japanese Patent Publication No. 56-51336 discloses that a fluorescent whitening agent having a bis (alkyl-substituted benzoxazolyl) naphthalene structure is contained in a resin layer. Further, use of bis (methylbenzoxazolyl) stilbene is disclosed as a comparative example. JP
JP-A-61-75341 discloses a technique for incorporating a quinacridone-based reddish 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. For a technique of adding a whitening agent such as bis (alkyl-substituted benzoxazolyl) thiophene to a resin composition to improve whiteness, a photographic material using the coated paper as a support is coated with an acidic hardening solution. When processed with, there was a problem that, instead of improving the whiteness, it became rather yellow.

As a result of the study by the present inventors, a fluorescent agent, particularly a bis (benzoxazolyl) naphthalene-based fluorescent agent or a bis (benzoxazolyl) stilbene-based fluorescent agent, and titanium oxide, particularly an inorganic-treated titanium oxide pigment, were used. When melt-extrusion coating a polyolefin resin composition containing a slit die on a substrate in the form of a film, the generation of die lip stains is promoted, and the resin composition further comprises an inorganic or organic coloring pigment or coloring dye, especially a blue-based coloring composition. It has been found that when a coloring pigment or a coloring dye is contained, there is a problem that generation of die lip stain is further promoted.

The third problem is the problem of die lip stain. Even without an organic surface treatment or combined use with a fluorescent agent, the incorporation of a titanium oxide pigment in a high concentration in polyethylene itself causes die lip contamination, which is a serious problem in operation.

As a method for solving such a problem, Japanese Patent Publication No. Sho 59-1473
No. 4 discloses that the physical property value n of the resin composition measured at 200 ° C. and 1000 S ⁻¹ is 5 or less.

However, if the physical property value n is set to 5 or less according to this method, the peeling between the cooling roll and the resin surface tends to be incomplete during the production of the resin-coated paper, and there has been a problem that fine avatar-like scratches are generated particularly when processed at high speed.

[Object of the invention]

Accordingly, an object of the present invention is to guarantee high sharpness as a photographic paper with high titanium oxide dispersibility, high whiteness, no unevenness due to streaky coating thickness irregularity occurring at the time of processing, and avatar-like scratches. To provide a resin-coated paper type photographic support.

(Configuration of the present invention)

An object of the present invention is to provide a photographic support in which paper is used as a substrate and both surfaces of which are coated with a polyolefin, and a polyethylene resin layer containing a) a fluorescent agent and b) an organic surface-treated titanium oxide is provided on the side where an image is provided. It can be achieved by a photographic support having a resin composition having a physical property value n of 4.0 or less at 200 ° C. and a shear rate of 1000 / sec determined by the method described below.

 The definition of the physical property value n referred to in this specification is as follows.

There is a stock cylinder part 8 having a diameter (d) of 10 mm, a capillary part 9 having a diameter (D) of 1.5 mm, and a connecting part connecting them (FIG. 1).
2) using a capillary rheometer at 45 ° C,
Keep these parts at a constant temperature,
Is filled with a resin composition. By descending the descending beam 1 at a constant speed, pressure is applied to the resin composition through the load cell 2, the plunger 3, and the spacer 4 which is in close contact with the inner wall of the stock cylinder, and the resin composition is extruded at a constant shearing speed by the capillary 9, which is generated at that time. The resistance force to be applied is detected by the load cell.

This measurement was performed for three types of capillaries having a capillary length (L) of 10 mm, 20 mm, and 30 mm.
P is plotted against D (Fig. 3), and the value indicating the distance from the intersection of the L / D axis to the origin in L / D units is defined as the physical property value n. .

Although the physical property value n is the physical property value as described above, the physical property value n is described in “JOUNAL OF APPLIED PHYSICS: Vol 2
8, No. 5, May 1957, pp. 624-627 ".

The present inventors have conducted intensive studies and found that a) a polyethylene resin composition containing (a) a fluorescent agent, (b) an organic surface-treated titanium oxide, and a physical property value n of 4.0 measured at 200 ° C. and a shear rate of 1000 / sec. A photographic support obtained by melt-extrusion coating the following resin composition on the front side of the base paper has excellent dispersibility of titanium oxide pigment, that is, excellent sharpness when used as photographic paper, high whiteness, and streak-like coating amount. It was found that no unevenness occurred and no avatar-like scratches occurred.

The individual elements of the configuration of the present invention are already known, and although the effects of each combination can be predicted to some extent, the extent of the influence of each technology on items other than the original purpose is completely unknown. Was. The effect on avatar-shaped scratches has been clarified for the first time by the present inventors.

As the fluorescent agent used in the present invention, a fluorescent agent of the general formula [I] or [II] is preferably used.

(In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R ₈ each represent a hydrogen atom or an organic residue.) 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} .

In addition, 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, A masterbatch or compound comprising an agent such as a fatty acid metal salt 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.

As the organic surface-treated titanium oxide used in the present invention, alkanolamine-treated titanium oxide, low molecular weight polyhydric alcohol-treated titanium oxide, and the like are preferably used.

Specifically, alkanolamines such as ethanolamine, butanolamine, diethanolamine, N-methylethanolamine, triethanolamine, N, N-dibutylpropanolamine, ethylene glycol, propylene glycol, 1,3-dihydroxybutane, 4-dihydroxybutane, pentaethylene glycol, 2,5-
Dihydroxyhexane, 2,4-dihydroxy-2-methylpentane, heptamethylene glycol, dodecamethylene glycol, glycerin, trimethylolethane, trimethylolpropane, 2,4-dihydroxy-3-hydroxymethylpentane, 1,2,6- Hexanetriol,
Titanium oxide which has been surface-treated with a di- or tetravalent low-molecular-weight alcohol such as 2,2-bis (hydroxymethyl) -3-butanol and pentaerythritol is exemplified.

The treatment amount is preferably 0.1 to 5% by weight for alkanolamines, and 0.1 to 1.5% by weight for low molecular weight polyhydric alcohols.

The crystal form of titanium oxide may be either an anatase type or a rutile type, but the rutile type is more preferable in consideration of the sharpness of photographic paper.

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,
This is a problem because the resolving power is reduced. If it exceeds 40% by weight, the fluidity is lowered, which is not preferable. The range of 7 to 30% by weight is preferable, and the range of 9 to 25% by weight is particularly preferable. As a method for incorporating the titanium oxide pigment into the resin composition of the photographic support, a so-called masterbatch in which titanium dioxide is contained in a polyolefin in a predetermined concentration in advance is prepared, and they are diluted at 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-60-75832.
-181131, etc., or the method of illustration.

In the practice of the present invention, as a method of reducing the physical property value n of the resin composition to 4 or less at a shear rate of 1000 / sec at 200 ° C., a combination of resins having the physical property value n of a single resin of 4 or less is used. It can be found relatively easily by searching.

Pulp constituting base paper used in the practice of the present invention includes JP-A-58-37642, JP-A-60-67940, JP-A-60-69649, JP-A-61-35442 and the like. It is advantageous to use appropriately selected natural pulp as described or exemplified in the above, but if necessary, synthetic pulp and synthetic fibers other than natural pulp 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, and softwood pulp mixed pulp is advantageously used, and various pulp such as kraft pulp, sulfite pulp, and 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, described in JP-A-54-147211. Epoxidized higher fatty acid amides and organic fluoro compounds described in JP-A-56-109343 can be mentioned.

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 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.

Further, as the cationic, anionic or amphoteric paper strength enhancer, cationized starch described or exemplified in JP-B-60-17103, cationic polyvinyl alcohol described or exemplified in JP-A-63-214748, JP
No. 57-185432, cationic polyacrylamide described or exemplified in JP-A-57-197539.
No. 23119, JP-B-62-31118 or anionic polyacrylamide described or exemplified in JP-B-61-37613.
And the amphoteric polyacrylamide described or exemplified in JP-A-59-31949, and the vegetable galactomannan described or exemplified in JP-A-59-125731. Their addition amount is preferably in the range of 0.05 to 8% by weight, particularly preferably in the range of 0.15 to 4% by weight, based on the pulp dry weight.

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, such as caustic soda and sodium carbonate, coloring pigments, coloring dyes, and fluorescent whitening agents are described in JP-A-54-147033, JP-A-63-204251, and JP-A-1-265637. Alternatively, examples may be included in appropriate combinations.

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 JP-A 1-266537, and JP-A 1-266537 as an antistatic agent. JP-A-58-82, alkali metal salts such as sodium chloride and potassium chloride, alkaline earth metal salts such as calcium chloride and barium chloride, and colloidal metal oxides such as colloidal silica described or exemplified in
No. 242, or an organic antistatic agent described or exemplified,
Latex and emulsions include petroleum resin emulsion, styrene-acrylic acid-acrylate copolymer, styrene-acrylic acid-butadiene copolymer, ethylene-vinyl acetate copolymer, styrene-maleic acid-
Latexes such as acrylate copolymers, as pigments, clay, kaolin, talc, barium sulfate, titanium oxide, etc., as a pH regulator, 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 practice 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 and JP-A-61-260240 disclose. It is advantageous to employ an appropriate papermaking method as described or exemplified in JP-A-61-284762. The thickness of the base paper is not particularly limited, but after the base paper is formed, the base paper is calendered as described or exemplified in JP-A-58-37642 and JP-A-60-126397. Is preferred, and its basis weight is 40 g / m ^{2 to} 250 g / m ²
Are preferred.

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.

The resin layer on the image forming side of the photographic support in the present invention contains 7 to 30% by weight of a titanium dioxide pigment. In the case of a multi-layer resin-coated paper, the lower resin layer contains May or may not contain a titanium dioxide pigment. Also, in the polyolefin resin, zinc oxide, talc, white pigments such as calcium carbonate, stearamide, fatty acid amides such as arachidic amide,
Fatty acid metal salts such as zinc stearate, calcium stearate, aluminum stearate, magnesium stearate, zirconium octylate, sodium palmitate, calcium palmitate, sodium laurate, tetrakis [methylene-3 (3,5-di-tert- Butyl-4-hydroxyphenyl) propionate] methane, antioxidants such as 2,6-di-tert-butyl-4-methylphenol, blue pigments and dyes such as coparto blue, navy blue, ultramarine, cerulean blue, and phthalocyanine blue; Magenta pigments and dyes such as cobalt violet, fast violet and manganese violet, tinuvin
It is preferable to add various additives such as ultraviolet absorbers such as 320, Tinuvin 326, and Tinuvin 328 (trade names of Ciba-Geigy) in appropriate combination.

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. In that case, 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, preferably continuously, extrusion-coated, so-called tandem extrusion system or outermost resin layer. It is preferred to use a so-called co-extrusion coating system in which the inner and inner resin layers are simultaneously extrusion coated in multiple layers. 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 a photographic paper of such a degree that the gloss of the surface of the photographic paper is not affected when photographic paper is used.
No. 55-26507, which has a fine rough surface or matte surface, a silk surface, etc., the back surface is usually a matte surface, and the surface or both front and back surfaces as required, such as corona discharge treatment, flame treatment, etc. Treatment can be performed. Further, after the activation treatment, an undercoating treatment as described in JP-A-61-84643 can be performed. Further, the thickness of the resin layer on the front and back of the resin-coated paper is not particularly limited, but generally 10μ ~ 50μ
Extrusion coated to a moderate thickness is advantageous.

Various pack coat layers can be coated on the photographic support in the present invention for the purpose of preventing static charge and curling. In addition, the pack coat layer includes
JP, JP-B-57-9059, JP-B-57-53940, JP-B-58-56859, JP-A-59-214849, JP-A-58-184144, etc. An inorganic antistatic agent, an organic antistatic agent, a hydrophilic binder, a latex, a curing agent, a pigment, a surfactant and the like can be appropriately combined and contained.

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, a fluorescent brightener, 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 in a suitable combination 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, CD-IV
(The above two compounds are commercial products of Kodak Co., Ltd.) and droxychrome (trade name of May and Baker Co., Ltd.) can be processed with a color developing solution of any principal agent. A developing solution containing such a base may contain a development accelerator such as benzyl alcohol, thallium salt, or phenidone. Also,
Processing can also be carried out with a developer substantially free of benzyl alcohol.

〔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. 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,
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 ² , MI = 5) low density polyethylene (density 0.92 g / cm ² ,
A 1: 1 mixture of MI = 5) was coated at a resin temperature of 330 ° C. to a thickness of 30 μm using a melt extrusion coater. Then, the resin compositions shown in Table 1 were mixed well on the surface of the base paper, and a screw type extruder having an extrusion opening diameter of 65 mm and a 750 mm wide T-type extruder were used.
30μ at a resin temperature of 320 ° C using a melt extruder with a die
m, and photographic supports each containing a titanium oxide pigment or the like were produced. 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. At this time, the upper limit coating speed at which no bruising was generated on the surface resin surface was recorded for each resin composition.
The number of die lip stains 2 hours after the start of melt extrusion of each resin composition was recorded under the conditions of a coating speed of 120 m / min.

 The numerical values in the table represent parts by weight.

(Note) 1: 50 parts by weight of rutile type titanium oxide with 0.5% by weight of titanium oxide (as Al ₂ O ₃ ), 50 parts by weight of low density polyethylene with a density of 0.918 g / cm ³ and MI 8 Master Badge.

Note 2: rutile titanium oxide 50 parts by weight of the hydrous alumina surface coverage versus titanium oxide 0.5% by weight (as Al ₂ O _3), ultramarine 1.25 parts by weight, low density polyethylene having a density of 0.918g / cm ^3, MI 8 Master batch consisting of 48.75 parts by weight.

(Note) 3: 50 parts by weight of rutile type titanium oxide with 0.5% by weight of titanium oxide (as Al ₂ O ₃ ) and 0.5% by weight of titanium oxide with respect to hydrated alumina surface coverage.
A masterbatch composed of 0.918 g / cm ³ and 50 parts by weight of low-density polyethylene having an MI of 8.

(Note) 4: 50 parts by weight of rutile type titanium oxide with 0.5% by weight of titanium oxide (as Al ₂ O ₃ ), 0.5% by weight of titanium oxide, and 1.25 parts by weight of ultramarine blue, A masterbatch consisting of 48.75 parts by weight of low density polyethylene having a density of 0.918 g / cm ³ and MI 8.

(Note) 5: 50 parts by weight of rutile type titanium oxide with 0.5% by weight of titanium oxide (as Al ₂ O ₃ ) relative to the surface coverage of hydrated alumina, density
A masterbatch consisting of 0.918 g / cm ² and 50 parts by weight of low-density polyethylene with MI9.

(Note) 6: Low-density polyethylene with 50% by weight of rutile-type titanium oxide, 1.25 parts by weight of ultramarine, density of 0.918 g / cm ³ , MI 9 with 0.5% by weight of titanium oxide (as Al ₂ O ₃ ) relative to the surface coverage of hydrous alumina Master batch consisting of 48.75 parts by weight.

(Note) 7: 50 parts by weight of rutile-type titanium oxide with 0.5% by weight of titanium oxide (as Al ₂ O ₃ ) and 0.5% by weight of titanium oxide with respect to the surface coverage of hydrated alumina, and a density of 0.918 g / cm. ³ 、 Master batch consisting of 50 parts by weight of low-density polyethylene of MI9.

Note 8: (as Al ₂ O ₃₎ hydrous alumina surface coverage versus oxide Chintan 0.5 wt%, the rutile type titanium oxide 50 parts by weight of 0.5 wt% Triethanolamine surface coverage versus titanium oxide, ultramarine 1.25 parts by weight, A masterbatch consisting of 48.75 parts by weight of low density polyethylene having a density of 0.918 g / cm ³ and MI 9

(Note) 9: Master batch consisting of 10 parts by weight of cobalt blue # 3 manufactured by The Shepard Color Company, 90 parts by weight of low-density polyethylene having a density of 0.918 g / cm ³ and MI8.

(Note) 10: Chromophthal Blue A3R (manufactured by Ciba-Geigy) 0.1 parts by weight, low molecular weight polyethylene 0.1 parts by weight, density 0.
Master batch consisting of 99.8 parts by weight of low-density polyethylene of 918 g / cm ³ and MI 8.

(Note) 11: 2 parts by weight of fluorescent agent of structural formula [XIV], density 0.918g
Master batch consisting of 98 parts by weight of low-density polyethylene having an MI / cm ³ and MI 8.

(Note) 12: A masterbatch comprising 0.2 parts by weight of a fluorescent agent of the structural formula [III], 0.2 parts by weight of low-molecular-weight polyethylene, 0.918 g / cm ³ and 99.6 parts by weight of low-density polyethylene of MI8.

(Note) 13: A masterbatch comprising 0.2 parts by weight of a fluorescent agent of the structural formula [III], 0.2 parts by weight of low-molecular-weight polyethylene, 0.918 g / cm ³ , and 99.6 parts by weight of low-density polyethylene of MI9.

(Note) 14: Low density polyethylene with density of 0.918 g / cm ³ and MI 8.

(Note) 15: Low-density polyethylene with a density of 0.918 g / cm ³ and MI 9.

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. Evaluation criteria are white → ○, slightly yellow → △, yellow → × Sharpness evaluation method: A density chart for resolving power measurement is printed on black-and-white photographic paper, and the density difference of the dense line print image is measured by Union Optical Co., Ltd. microphotometer. And the value represented by the following equation was defined as the resolving power.

here, The results are shown in Table 2.

As can be seen from Table 2, the samples containing the fluorescent agent and the organic surface-treated titanium oxide (,,,) have increased lip contamination as compared with the standard sample (). On the other hand, the samples (,,) having the physical property value n of 4 or less have a lower upper limit coating speed.
On the other hand, only the sample of the present invention is manufactured at a high speed, has no avatar-like scratches, has few streaks due to lip contamination, is white, and has high resolution.

Example 2 The organic surface treatment of titanium oxide of the sample of Example 1 was performed in the third step.
The results in Table 3 were obtained in the same manner except that the surface treatment described in the table was used.

It can be seen that if the amount of organic surface treatment is small, there is no curing, and if it is too large, die lip stains increase.

Example 3 The results in Table 4 were obtained in the same manner as in Example 1 except that the total content of titanium oxide in the sample of Example 1 was changed to the amount shown in Table 4.

It can be seen that when the content of titanium oxide is small, the resolving power is insufficient, and when it is too large, die lip stain increases.

Example 4 The procedure of Example 1 was repeated except that Table 1 was replaced with Table 5, and the results in Table 6 were obtained.

(Note) 16: 50 parts by weight of rutile type titanium oxide with 0.5% by weight of titanium oxide (as Al ₂ O ₃ ), 0.5% by weight of titanium oxide, and 2.5% by weight of zinc stearate. parts, density 0.918 g / cm ^3, MI
Master batch consisting of 47.5 parts by weight of 9 low density polyethylene.

(Note) 17: 50 parts by weight of rutile type titanium oxide with 0.5% by weight of titanium oxide (as Al ₂ O ₃ ), 0.5% by weight of titanium oxide, and 1.25 parts by weight of ultramarine blue, A masterbatch comprising 2.5 parts by weight of zinc stearate, 46.25 parts by weight of low-density polyethylene having a density of 0.918 g / cm ³ and MI9.

(Note) 18: A masterbatch comprising 0.2 parts by weight of a fluorescent agent of the structural formula [IV], 0.2 parts by weight of low-molecular-weight polyethylene, 0.918 g / cm ³ and 99.6 parts by weight of low-density polyethylene of MI9.

(Note) 19: Masterbatch composed of 0.2 parts by weight of the fluorescent agent of the structural formula [VII], 0.2 parts by weight of low-molecular-weight polyethylene, low-density polyethylene having a density of 0.918 g / cm ³ and MI9.

Note 20: High-density polyethylene with a density of 0.960 g / cm ³ and MI 7.

Note 21: Low-density polyethylene with a density of 0.918 g / cm ³ and MI 9.

It can be seen that if the amount of the fluorescent agent used is small, the whiteness improving effect is small and if the amount is too large, the whiteness improving effect is saturated and the dilip stain tends to increase.

Example 5 The same operation was performed except that the titanium oxide of Example 4 was not coated with hydrated alumina, and similar results were obtained.

〔The invention's effect〕

When the present invention is carried out, a photographic support having high dispersibility of titanium oxide, high sharpness, high whiteness, no streak-like thickness irregularity, and no avatar-like scratches can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of the outline of a capillary rheometer. FIG. 2 is a sectional view of a capillary portion. FIG. -3 is a graph in which measured values are plotted. In the figure, 1 is a descending beam, 2 is a load cell, 3 is a plunger, 4 is a spacer, 5 is a cylinder block, 6 is a capillary block, 7 is a thermostat,
8 is a stock cylinder, 9 is a capillary. 8 has a cylinder diameter d of 10 mm, 9 has a capillary diameter D of 1.5 m
m, capillary length L is 10mm, 20mm, 30mm,
The angle θ in Figure 2 is 45 degrees. In FIG. 3, the Y axis is stress, and the X axis is
L / D.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI B32B 27/32 B32B 27/32 Z (56) References JP-A-57-109948 (JP, A) JP-A-2-850 ( JP, A) JP-A-55-113040 (JP, A) JP-A-58-75151 (JP, A) JP-A-52-29215 (JP, A) JP-A-2-502761 (JP, A) (58) ) Surveyed field (Int.Cl. ⁶ , DB name) G03C 1/79

Claims (4)

(57) [Claims] 1. A photographic support in which paper is used as a substrate and the both surfaces of which are coated with polyolefin, a side on which an image is provided has a polyethylene resin layer containing a) a fluorescent agent and b) an organic surface-treated titanium oxide. And the physical property value n of the resin composition obtained by the method described below is 200 ° C., and the shear rate is 1000 / se.
A photographic support, wherein c is 4.0 or less. Definition of the physical property value n: there are a stock cylinder portion 8 having a diameter (d) of 10 mm, a capillary portion 9 having a diameter (D) of 1.5 mm, and a connecting portion connecting them, and the connecting portion has a conical shape and an angle θ of 45 °. Using a capillary rheometer, these parts are maintained at a constant temperature, and the stock cylinder part 8 is filled with the resin composition. By descending the descending beam 1 at a constant speed,
Pressure is applied to the resin composition via the load cell 2, the plunger 3, and the spacer 4 which is in close contact with the inner wall of the stock cylinder, and the resin composition is extruded from the capillary section 9 at a constant shear rate.
The resistance generated at that time is detected by the load cell 2. This measurement is performed for three types of capillaries having a capillary length (L) of 10 mm, 20 mm, and 30 mm. The obtained measurement values are plotted against L / D, and a straight line obtained by the least squares method and L / D are obtained. A value indicating the interval from the intersection with the axis to the origin in L / D units is a physical property value n. 2. The method according to claim 1, wherein the titanium oxide is 0.1% by weight of the titanium oxide.
2. A photographic support according to claim 1, which is surface-treated with 0.1 to 1.5% by weight of low molecular weight polyhydric alcohol based on the weight of alkanolamine or titanium oxide of .about.5.0% by weight. 3. The photographic support according to claim 1, wherein the content of the organic surface-treated titanium oxide in the polyethylene resin layer is 9 to 25% by weight. 4. The fluorescent agent is at least one of bis- (2-benzoxazolyl) -1,4-naphthalene type and bis- (2-benzoxazolyl) -4,4'-stilbene type fluorescent agent. 4. The photographic support according to claim 1, wherein the content of the fluorescent agent is 0.5 to 10 mg / m ² .