JPH0391740A - Photographic base - Google Patents

Abstract

PURPOSE:To provide the photographic base of a resin coated paper type which has the high sharpness of printed images and lessens the formation of die lip stains at the time of production of the photographic base by coating the surface of paper, synthetic paper or film base body with a polyolefin resin compsn. contg. a specific titanium dioxide pigment, specific fluorescent agent and coloring material. CONSTITUTION:(A) the titanium dioxide pigment which has 0.110 to 0.150 mum particle size indicated by the number average diameter in the constant direction measurement by an electron microscope and is subjected to a surface treatment with a hydrous metal oxide contg. an aluminum atom or is internally treated with an aluminum compd., (B) the bis (benzoozazolyl) naphthalene fluoresent agent having a substituent or bis (benzooxasolyl) stilbene fluorescent agent having a substituent and (C) the coloring pigment or coloring dye are incorporated into the polyolefin resin compsn. The titanium dioxide of a rutile structure, anatase structure, and the mixed crystals of the rutile structure and anatase structure are all usable as the above-mentioned titanium oxide pigment. The pigment of the rutile structure is more preferable in order to obtain the photographic base having the particularly high sharpness of the printed images.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a resin-coated paper-type photographic support in which at least one side of a paper, synthetic paper or film substrate is coated with a polyolefin resin containing a titanium dioxide pigment. In detail, the printed image has high nail sharpness, high brightness, and looks white, and there is very little die lip stain generation during the production of photographic supports, so it has excellent surface quality. This invention relates to photographic supports.

[Conventional technology]

As a photographic support, a resin-coated paper-type photographic support in which at least one side of the substrate is coated with a resin composition comprising at least a tan dioxide pigment and a polyolefin resin is well known. For example, U.S. Patent No. 3,501,2
No. 98 discloses a technique for a photographic support in which both sides of a paper substrate are coated with a polyolefin resin. Furthermore, since rapid photographic processing was applied, photographic supports in which both sides of base paper for photographic paper are coated with polyethylene resin have been mainly used for photographic paper, and image formation on one side The side resin layer usually contains a titanium dioxide pigment to impart sharpness.

Conventionally, anatase-type and rutile-type titanium dioxide pigments are known as titanium dioxide pigments contained in the resin layer on the image forming side of a resin-coated paper-type photographic support. In addition, titanium dioxide pigments whose surfaces are not coated, or titanium dioxide particles whose surfaces are hydrated aluminum oxide, such as those described or exemplified in JP-A-52-35625 and JP-A-57-108849, Titanium dioxide pigments coated with hydrous metal oxides such as hydrous silicon oxide, as well as JP-A-5235625, JP-B No. 58-4373'4, JP-B No. 61-2655
Titanium dioxide pigments are known in which the surface of titanium dioxide particles is coated with an organic substance such as polyhydric alcohol, its derivative, polyorganosiloxane or its derivative, as described or exemplified in No. 2, etc. .

On the other hand, if particularly high sharpness of the printed image is required as a photographic support, some resin-coated paper-type photographic supports are also known.

For example, (1) a resin layer containing a titanium dioxide pigment at a high concentration, (2) a resin layer containing a rutile-type titanium dioxide pigment, (3) a resin layer containing a rutile-type titanium dioxide pigment, and (3) a resin layer containing titanium dioxide pigment in a high concentration. As described in No. 43734, etc., a resin layer containing a titanium dioxide pigment by adding a surfactant represented by a metal soap such as zinc stearate, calcium stearate, or zinc palmitate; (4) resin As the titanium dioxide pigment in the layer, a so-called organically treated titanium dioxide pigment whose particle surface is coated with the above-mentioned organic substance is known.

However, these resin-coated paper-type photographic supports
The reality is that the intended sharpness is insufficient, and there are other serious problems with photographic suitability and manufacturing suitability, and satisfactory results have not yet been achieved.

First, when the concentration of titanium dioxide pigment in the resin layer of a polyolefin resin-coated paper-type photographic support is increased,
Although photographic supports with high print image sharpness can be obtained, serious problems in photographic suitability and manufacturability often occur. That is, when a polyolefin resin composition containing a titanium dioxide pigment, especially a polyethylene resin composition, is melt-extruded and coated onto a substrate in the form of a film from a slit die, a needle-like or icicle-like shape is formed at the tip of the die lip during short extrusion. Die-lip stains (hereinafter referred to simply as die-lip stains) tend to form, and, to make matters worse, these die-lip stains tend to grow larger and larger as the melt extrusion time progresses.

If this die lip stain occurs during melt extrusion coating, vertical streaks may occur on the surface of the polyolefin resin-coated paper produced as is, or streak-like unevenness may occur due to uneven coating amount. Sometimes, dirt adheres to the film and is applied, causing foreign matter to appear. As a result, the surface quality of polyolefin resin-coated paper is significantly impaired.
The problem was that it was completely unsuitable as a photographic support that required excellent surface quality and had no commercial value. In addition, the only way to completely remove the die lip dirt once it has occurred is to stop production and clean the die lip or replace the die, and cleaning or replacing the die requires a great deal of effort and time. There was a problem in that it caused a significant decrease in productivity.

In the first place, the titanium dioxide pigment in the resin layer of a polyolefin resin-coated paper-type photographic support has strict quality requirements, so the surface of the titanium dioxide particles is coated with a hydrous metal oxide such as hydrous aluminum oxide or hydrous silicon oxide. Processed.
Titanium dioxide pigments (hereinafter simply referred to as hydrous metal oxide treated titanium dioxide pigments) are mainly used, and so-called untreated titanium dioxide pigments, which have not undergone any surface treatment, are rarely used. do not have. However, when a hydrous metal oxide-treated titanium dioxide pigment is used, the more highly the hydrous metal oxide treatment is performed, the more severe die lip staining becomes. On the other hand, when an untreated titanium dioxide pigment is used, the occurrence of gripp stains is small, but the resin layer suffers significant photodeterioration and is prone to discoloration over time.

In order to solve these problems, for example, Japanese Patent Laid-Open No. 57-108849 discloses a photographic support in which a titanium dioxide pigment whose surface is lightly treated with hydrous aluminum oxide is applied to titanium dioxide. ing. However, even with this technique, when the titanium dioxide pigment in the polyolefin resin composition is considerably increased in order to achieve high sharpness of printed images, there is a problem in that die lip stains occur to some extent.

Second, when a rutile-type titanium dioxide pigment is used as the titanium dioxide pigment contained in the resin layer of a polyolefin resin-coated paper-type photographic support, the print quality is lower than when an anatase-type titanium dioxide pigment is used. Although photographic supports with fairly high image sharpness are obtained, other serious photographic suitability problems arise. That is, the resin surface containing the titanium dioxide pigment on the image forming side of the photographic support has a yellowish tinge due to the rutile titanium dioxide, making it impossible to obtain a photographic support with clear whiteness, resulting in a bright white background. There was a problem that prints could not be obtained.

Thirdly, as a result of studies by the present inventors, when incorporating a titanium dioxide pigment into the resin layer of a paper-type photographic support coated with a polyolefin resin, metal soaps such as zinc stearate, calcium stearate, and zinc palmitate are used. It has been found that there is a problem in that even if a surfactant such as typified by the following is added, the sharpness of the printed image of the photographic support is not substantially improved at all.

In general, a method for incorporating titanium dioxide pigment into the resin layer of a paper-type photographic support coated with a polyolefin resin is to use a conventional melt-kneading machine such as a Banbury mixer or a 21-dar kneading extruder to mix the pigment in advance. You can create a so-called masterbatch containing a high concentration of pigment in the resin, dilute it with a diluted resin to the desired ratio, and then apply it by melt extrusion, or apply the pigment in the resin from the beginning. It is usual to prepare a so-called compound containing only a desired composition ratio and apply it by melt extrusion. In addition, the main purpose of the metal soap originally added to the resin layer of a paper-type photographic support coated with a polyolefin resin is when the photographic support is manufactured by melt extrusion coating. and the resin-coated surface.

However, as a result of studies conducted by the present inventors, completely new findings regarding the effects of metal soap in the resin layer were discovered. That is, the concentration of metal soap added when preparing a titanium dioxide pigment masterbatch or compound in the resin layer of a polyolefin resin-coated paper-type photographic support is 1.5% by weight based on the titanium dioxide pigment. , and the sharpness of the printed image of the photographic support increases up to 0.15% by weight based on the resin composition, but at this content,
Poor releasability, and 1.
5% to 7.5% by weight and 0.15% to O based on the resin composition. At a content in the range of 75% by weight, the peelability improves with increasing amount, but the sharpness of the printed image on the photographic support is considerably lower, sometimes lower than without metal soap. It turned out to be true.

Furthermore, if the content is higher than that, the sharpness of the printed image on the photographic support will gradually decrease with the amount added.
It was found that the generation of oil smoke increased and the suitability for manufacturing during melt extrusion coating became extremely poor. As described above, even if metal soap is added when blending titanium dioxide pigment into the resin layer of a polyolefin resin-coated paper-type photographic support, a photographic support with high print image sharpness cannot be obtained. There was a problem.

Fourthly, as a result of studies by the present inventors, it has been found that even if a so-called organically treated titanium dioxide pigment is used as the titanium dioxide pigment contained in the resin layer of a paper-type photographic support coated with a polyolefin resin, the photographic support It has been found that there is a problem in that the sharpness of the body print image is not substantially high at all. That is, a metal soap such as zinc stearate is added to the resin layer of a paper-type photographic support coated with a polyolefin resin together with an organically treated titanium dioxide pigment in an amount that will exhibit sufficient releasability during the production of the photographic support. It has been found that, when added, the sharpness of printed images on the photographic support is almost the same or only slightly higher than when titanium dioxide pigments without organic treatment are used. .

On the other hand, several techniques are known for improving the whiteness of a resin layer containing a titanium dioxide pigment on the image forming side of a resin-coated paper-type photographic support.

U.S. Patent No. 3,501. , No. 298, in addition to titanium dioxide pigments, blue-tinted inorganic pigments such as ultramarine and cobalt blue, and red-tinted inorganic pigments of cobalt oxide phosphate (Fe
Rasphc++yV made by mto Colors Cup
-6260), containing quinacridone red which is a reddish organic pigment, and Ltyilex H (CIB
It is known to contain a fluorescent agent having a bis(alkyl-substituted benzoxolyl)thiophene structure represented by A (trade name, manufactured by GEIGY). Japanese Patent Publication No. 51-6531
No. 3 discloses that it contains a titanium dioxide pigment treated with hydrated alumina and an optical brightener. Unexamined Japanese Patent Publication No. 1973 3-1. No. 9021 contains cosmetic ultramarine called ultramarine, which is a blue-tinted inorganic pigment, and Daiichi Bink DP-1, which is a red-tinted inorganic pigment, and Daiichi Violet t4) V-1 (both manufactured by Daiichi Kaebisu Kogyo). is disclosed. Furthermore, Japanese Patent Publication No. 56-51336 discloses that a fluorescent agent having a bis(alkyl-substituted benzoxazolyl)naphthalene structure is contained in a resin layer. Japanese Patent Application Publication No. 1986 1. No. 75341 discloses a technique for incorporating a quinacridone-based reddish organic pigment into a resin. Also, U.S. Patent No. 4,794,071
No. 3, discloses the inclusion of a mixture of bis(benzooxazolyl)stilbene fluorescent agents.

However, each of these techniques has drawbacks.

First, an inorganic or organic coloring pigment or dye is contained in the resin on the image forming side of the resin-coated paper-type photographic support to create a yellowish tinge due to the titanium dioxide pigment contained in a high concentration. As for the technology that neutralizes this tendency and improves the visual whiteness, since it is made to appear white by coloring, there is a problem that the brightness decreases and it is difficult to obtain clear whiteness. Further, as a result of studies by the present inventors, it has been found that a polyolefin resin composition containing an inorganic or organic colored pigment or colored dye, particularly an inorganic colored pigment and a titanium dioxide pigment, particularly an inorganic treated titanium dioxide pigment, can be produced from a slit die. It has been found that there is a problem in that die lip staining is promoted when melt extrusion coating is applied onto a substrate in the form of a film.

Second, as a result of our studies, we found that fluorescent agents, especially bis(
A polyolefin resin composition containing a benzoxazolyl) naphthalene-based fluorescent agent or a bis(benzooxazolyl)stilbene-based fluorescent agent and a titanium dioxide pigment, particularly an inorganically treated titanium dioxide pigment, is formed into a film from a slit die onto a substrate. When melt extrusion coating is applied to a resin composition, the occurrence of die lip stains is promoted, and when the resin composition contains an inorganic or organic coloring pigment or coloring dye, especially an inorganic coloring pigment, the occurrence of die lip stains is further promoted. It turned out that there was a problem.

Thirdly, a fluorescent agent having a bis(benzoxazolyl)thiophene structure having a substituent described or exemplified in U.S. Pat. Regarding the technology of adding the following fluorescent agent having a bis(benzoxazolyl)naphthalene structure having a lower alkyl group to a resin composition to improve whiteness, the fluorescent agent tends to bleed out from the resin. However, not only is there a problem in the stability of color tone, but also there is a problem in adhesion to the photographic emulsion layer. In addition, when a fluorescent agent is included in a resin composition to make it white, the stability of the whiteness is poor, so-called weather resistance such as light resistance and dark fading is poor, and it gradually turns yellow over time. It also became clear that there was a problem. Furthermore, in the case of a resin-coated paper in which a fluorescent brightener having a bis(benzoxazolyl)thiophene structure having a substituent such as Ubitex OB is added to the resin layer, a photograph using the coated paper as a support may be used. When a material is treated with an acidic hardening fixer, there is a problem in that the whiteness of the material does not improve, but instead becomes yellow.

[Problem to be solved by the invention]

Accordingly, it is an object of the present invention to provide photographic print images with high sharpness and brightness by coating at least one side of a paper, synthetic paper or film substrate with a polyolefin resin composition containing a titanium dioxide pigment. To provide an excellent photographic support that is visually white and has good whiteness stability, and also has very little die lip staining during production of the photographic support, and therefore has good surface quality. be. , [
Means and Effects for Solving the Problems] In order to solve the above-mentioned problems, the inventors of the present invention, as a result of intensive studies, discovered that at least one surface of the paper, laminated paper, or film substrate was coated with a polyolefin resin composition. In the resin-coated paper-type photographic support, the polyolefin resin composition contains at least (A) a titanium dioxide pigment having a particle diameter of 0.110 μm to 0.150 μrn as expressed by the number average diameter measured in a direction using an electron microscope. and calculated in the form of anhydrous metal oxide per titanium dioxide. The surface is treated with a hydrous metal oxide containing at least aluminum atoms in an amount of more than 2% by weight and less than 1.8% by weight, and a silicon dioxide content of 0.4% by weight or more (including O), or calculated in the form of anhydrous metal oxide per titanium dioxide. A titanium dioxide pigment whose particle interior is treated with at least an aluminum compound in an amount of more than 2% by weight and less than 1.8% by weight, and (B) a bis(benzoxazolyl)naphthalene-based fluorescent agent having a substituent or a substituted one. It has been found that the objects of the present invention can be achieved by a photographic support characterized by containing a bis(benzoxazolyl)stilbene-based fluorescent agent having a group and (C) a colored pigment or a colored dye. did.

The titanium dioxide pigment used in the practice of the present invention includes:
The particle size is 0.110 μm to 0.150 μm expressed as a number average diameter in directional measurement using an electron microscope,
And those that have been surface-treated with a specific amount of a hydrous metal oxide containing at least an aluminum atom, or those that have been internally treated with at least a specific amount of an aluminum compound, have a rutile structure, anatase structure, and rutile and anatase structures. Mixed crystal structures or mixtures thereof, as well as those made by either the sulfuric acid method or the chlorine method, can be used, but in order to obtain a photographic support with particularly high print image sharpness, , those having a rutile structure are preferred. Note that titanium dioxide with a rutile structure (hereinafter simply referred to as rutile-type titanium dioxide) as used herein refers to one in which 90% by weight or more, preferably 95% by weight or more of its crystal structure has a rutile structure. .

In addition, the number average diameter measured in a directional measurement using an electron microscope in this specification refers to the length of titanium dioxide pigment particles 100
This is the average value obtained by directional measurement using an electron microscope for 0 particles, and is expressed in μm.

As a typical method for producing the titanium dioxide pigment used in the practice of the present invention, the sulfuric acid method can be produced by the following steps.

Raw ore → Digestion/Extraction → Standing/Crystallization Filtration/Concentration → Hydrolysis → Cleaning Calcining Grinding/Sizing Wet Grinding/Classification Surface treatment → Washing/Drying Finishing Grinding → Titanium dioxide pigment. In the case of the sulfuric acid method, iron sulfate is usually crystallized from a solution of ilmenite treated with sulfuric acid, and hydrated titanium oxide is formed by hydrolysis of the separated titanyl sulfate aqueous solution.
It is fired to develop its pigmentary properties. Hydrolysis of titanyl sulfate aqueous solution can be carried out by adding titanyl sulfate solution to hot water to precipitate hydrous titanium oxide as seeds, or by using titanium water made by neutralizing titanyl sulfate or titanium tetrachloride. This can be done by a so-called external seeding method in which an oxide is added as a seed.

In addition, when producing rutile structure,
By setting the firing temperature to a higher temperature than in the case of manufacturing anatase structure, and by coexisting metal compounds such as sodium, potassium, and zinc to promote the formation of rutile structure during firing, the firing temperature is 800°C to 100°C. It will be done.

On the other hand, in the case of the chlorine method, titanium dioxide particles are formed by vapor-phase sintering decomposition of titanium tetrachloride at high temperature in an oxygen atmosphere, and generally have a rutile structure, which can be produced by the following process. .

High-purity ore or synthetic rutile chlorination → separation and condensation → purification → preheating → firing decomposition → separation → crushing and sizing → wet crushing and classification → surface treatment → washing and drying - final crushing → titanium dioxide pigment.

The product produced by calcination or vapor phase calcination decomposition will hereinafter be referred to as titanium dioxide linker. Titanium dioxide linker is dry-pulverized using a centrifugal roller mill such as a Raymond mill or a fluid energy mill such as an air mill, and the pulverized material is suspended in water to form a titanium dioxide slurry, which is then wet-pulverized by being subjected to a wet ball mill or vibration mill. wet classification using a continuous horizontal centrifuge and/or passing through a vibrating double-deck screen (325 mesh U.S. standard screen), hereinafter referred to as fines. A titanium dioxide slurry containing substantially no coarse particles of titanium dioxide is obtained. When the surface of titanium dioxide particles is treated with a hydrous metal oxide, the surface of the titanium dioxide particles is treated with a hydrous metal oxide containing at least aluminum atoms for fines that are still in a slurry form from which coarse particles have been removed. After the surface treatment, it is filtered and washed with water using a filter press, and then pulverized using an impact pulverizer and/or a fluid energy mill to produce a titanium dioxide pigment.

The titanium dioxide pigment used in the practice of the present invention has a particle diameter in the range of 0.110 μm to 0.150 μm, expressed as a number average diameter measured in a direction using an electron microscope, and is smaller than 0.110 μm. Photographic supports coated with polyolefin resin compositions containing titanium dioxide pigments having a number average diameter are problematic in that die lip stains occur frequently during production, resulting in poor sharpness of printed images.

On the other hand, a photographic support coated with a polyolefin resin composition containing a titanium dioxide pigment having a number average diameter larger than 0.150 μm has a problem in that the sharpness of the printed image becomes considerably low. The titanium dioxide pigment used in the practice of the present invention has a number average diameter of 0.115 μm because it causes very little die lip stain during the production of photographic supports and provides high sharpness of printed images.
Preferably, the thickness is in the range of 0.135 μm. A titanium dioxide pigment having a number average diameter of 0.110 μm to 0.150 μm can be obtained by manufacturing it under predetermined manufacturing conditions. The manufacturing conditions of the titanium dioxide pigment, particularly the firing temperature, firing time, and the type and amount of inorganic compounds present during firing, such as the inorganic compounds described or exemplified in Japanese Patent Publication No. 18718/1982, and their combined compounds, are as follows: , can be determined by measuring the number-average diameter of titanium dioxide pigments produced under a series of combinatorial experimental conditions in a directional electron microscopy measurement. At that time, the typical firing conditions that increase the number average diameter are high firing temperature, long firing time, and small amount of inorganic compounds present during firing, while the number average diameter decreases. Typical firing conditions include low firing temperature, short firing time, and large amount of inorganic compounds present during firing. The firing conditions for the titanium dioxide pigment used in the practice of the present invention include a firing temperature of 800°C to 1100°C, a firing time of 15 minutes to 5 hours, and an amount of inorganic compounds present in the form of inorganic oxides. Calculated from 0.2 weight per titanium dioxide
Particularly preferred are combination conditions in the range of 5% by weight.

The titanium dioxide pigment used in the practice of the present invention includes:
The particle surface is surface-treated with a specific amount of a hydrous metal oxide containing at least an aluminum atom, or the inside of the particle is internally treated with at least a specific amount of an aluminum compound, and the surface treatment and internal treatment are It may also be one that has been subjected to a combination treatment. Furthermore, in the case of a material that has been internally treated, it may be one that has not been surface-treated. In particular, when using the sulfuric acid method, from the viewpoint of designing titanium dioxide pigments, it is useful to have the particle surface treated with a hydrous metal oxide containing at least a specific amount of aluminum atoms.

The titanium dioxide pigment used in the present invention that has been surface-treated with a hydrous metal oxide has a particle surface of 0.2% in the form of anhydrous metal oxide per titanium dioxide after wet grinding and classification of titanium dioxide. Contains at least aluminum atoms in an amount greater than 1.8% by weight and less than 1.8% by weight, and has a silicon dioxide content of 0. 4% by weight or less (including 0)
treated with a hydrous metal oxide. The amount of titanium dioxide surface treated is 0. If it is less than 2% by weight, the weather resistance of the resin layer of the resin-coated paper-type photographic support containing the titanium dioxide pigment becomes poor, which is a problem. On the other hand, the processing amount is 1
．． If it is more than 8% by weight, the occurrence of greasy stains becomes significant, which is a problem. Preferred treatment amounts range from 0.35% to 1.5% by weight, particularly preferably 0.5% by weight, based on titanium dioxide in the form of anhydrous metal oxides.
-1.0% by weight. At least 0.4% by weight (contains at least aluminum atoms and contains silicon dioxide)
The hydrated metal oxide (including 0) is preferably surface-treated with hydrated aluminum oxide, and if necessary, the silicon dioxide content is less than 0.4% by weight, preferably 0.
．． Other hydrated metal oxides such as hydrated silicon oxide in an amount less than 2% by weight, or hydrated titanium oxide in a total amount of less than 1.8% by weight of anhydrous metal oxides, or a fraction of silicon dioxide may be used. 0. It is also possible to treat the surface with less than 4% by weight of hydrous silicon aluminum oxide.

In addition, as a method for treating the surface of titanium dioxide particles with a hydrous metal oxide, titanium dioxide slurry is wet-pulverized.
After classification, the pH is adjusted to 5 or higher, preferably 6 or higher, particularly preferably around 7, and then a water-soluble aluminum salt, if necessary, other water-soluble metal salts or water-soluble silicon compounds are added to the titanium dioxide slurry, and then By changing the pH in the slurry, poorly soluble hydrated aluminum oxide and, if necessary, other poorly soluble oxide hydrates can be precipitated onto the titanium dioxide pigment for surface treatment.

For example, a typical method for surface treatment in a reaction treatment tank equipped with a stirrer is to add a water-soluble alkaline solution such as caustic soda or potassium hydroxide to titanium dioxide slurry after wet grinding and classification. Slurry pH
7.0±1. Adjust to 0. Add an aluminate such as alkali aluminate to the pH-adjusted titanium dioxide slurry, and if necessary, add an aqueous solution of a water-soluble alkali such as caustic soda or potassium hydroxide, then reduce the pH to an alkaline slurry. In order to precipitate hydrous aluminum oxide on the surface of the titanium dioxide particles, the surfaces are treated by adding, for example, an aqueous solution of a mineral acid such as sulfuric acid or hydrochloric acid or a salt that exhibits an acidic reaction. The pH of titanium dioxide slurry after surface treatment is usually 7. 0±1
,0. Moreover, among alkali aluminates, sodium aluminate is particularly useful. In addition to the aluminate, the surface can be treated with other inorganic surface treatment agents. In this case, it can be added at any stage before, during or after the addition of the aluminate, but it is particularly advantageous to add it before the addition of the aluminate. Inorganic surface treatment agents other than aluminate used for these surface treatments include silicon compounds such as alkali silicates and silicon tetrachloride, titanium compounds such as titanium tetrachloride, and metals such as zirconium, zinc, and manganese. Various compounds such as compounds and phosphoric acid compounds can be used.

In addition, the titanium dioxide pigment used in the present invention that has been internally treated with an aluminum compound has an internal particle size of 0.00000, calculated in the form of AI203 per titanium dioxide.
Those internally treated with at least an aluminum compound in an amount greater than 2% and less than 1.8% by weight are useful. The processing amount inside titanium dioxide is 0. If it is less than 2% by weight, the weather resistance of the resin layer of the resin-coated paper-type photographic support containing the titanium dioxide pigment becomes poor, which is a problem.

On the other hand, if the treatment amount is 188% by weight or more, the occurrence of gripp stains increases, which is a problem. A preferred treatment amount range is from 0.35% to 1.5% by weight calculated in the form of Al203 based on titanium dioxide.

In the case of the sulfuric acid method, the aluminum compound used for internal treatment of titanium dioxide particles includes aluminum compounds such as aluminum chloride, aluminum sulfate, aluminum hydroxide, and sodium aluminate, with aluminum chloride and aluminum sulfate being preferred. .

Furthermore, in the case of the chlorine method, aluminum chloride is preferred. In addition, as a method for treating the inside of titanium dioxide particles with an aluminum compound, in the case of the sulfuric acid method, this is done by adding an aluminum compound before the calcination process, but the preferred process is to wash it after hydrolysis and then filter it. Either put the hydrated titanium oxide concentrated in a mixer, for example in a mixer, add an aluminum compound and mix well, or redisperse it in water in a mixing tank equipped with a stirrer and add the aluminum compound. After mixing well, it is made through a firing process. In the case of the chlorine method, for example, U.S. Pat.
121.641, by feeding an aluminum compound, preferably aluminum chloride, simultaneously with titanium tetrachloride and oxygen during the calcining process.

The titanium dioxide pigment used in the practice of the present invention can be used on the surface of a resin-coated paper-type photographic support containing the pigment in its resin layer after surface treatment or by internal treatment alone in order to further increase the sharpness of printed images on a resin-coated paper-type photographic support. For those without treatment, after wet grinding and classification, the electrical conductivity of the suspension described below is 60μ*/c
It is preferable to manufacture the product by washing it with water until it becomes less than m. The electrical conductivity of a suspension of titanium dioxide pigment herein is defined as follows.

After adding 10.0 g of titanium dioxide pigment to 100 ml of distilled water in a 100 ml beaker, the contents in the beaker were heated to a liquid temperature of 21.5 ml by stirring power using a rotor (rotation speed: 420 rpm/min) on a magnetic stirrer. °C±0.
Stir for 16 minutes while maintaining the temperature at 5°C to form a titanium dioxide pigment suspension. Sixteen minutes after the start of stirring, the electrical conductivity of the titanium dioxide pigment suspension is measured at 21.5° C.±0.5° C. using an electrical conductivity meter while stirring the suspension. The electrical conductivity thus obtained is defined as the titanium dioxide pigment suspension electrical conductivity in this specification.

The electrical conductivity of the suspension advantageously used in the practice of the invention is 6.
For titanium dioxide pigments with a concentration of 0 μU/cs or less, after surface treatment, or for those with only internal treatment and no surface treatment, after wet crushing and classification, filter the initial mother liquor with a filter press,
It is produced by subsequently washing the titanium dioxide cake in the filter press with running water until a titanium dioxide pigment with a suspension electrical conductivity of less than 60 μtJ/an is obtained. Washing conditions such as washing time, amount of water, and pressure of water were determined by subjecting the titanium dioxide cake collected under a series of combined experimental conditions to subsequent processing of drying and pulverization to obtain a titanium dioxide pigment. It can be determined by measuring the electrical conductivity of the suspension. Water washing can be carried out by using the slurry containing titanium dioxide as it is, or by resuspending the filter cake in the tank and replacing the accumulated water or supernatant liquid with water, or in combination with water washing in the filter press. It can also be done separately. Furthermore, from the viewpoint of further increasing the sharpness of printed images on photographic supports, the titanium dioxide pigment used in the practice of the present invention preferably has a suspension electrical conductivity of 55 μU/an or less, particularly 50 μU/an or less.
/am or less is more preferable.

The titanium dioxide pigment used in the practice of the present invention has the advantage of further increasing the sharpness of printed images on resin-coated paper-type photographic supports containing the pigment in the resin layer. Advantageously, it is produced by comminution in a fluid energy mill. As the fluid energy mill, a steam mill such as a micronizer is particularly preferred, but an air mill can also be used in combination. In addition, before pulverization is performed using a fluid energy mill, the first stage of pulverization is performed using an impact pulverizer such as a hammer mill, and then the second stage of pulverization is performed.
Particular preference is given to comminution in a fluid energy mill as a stage comminution.

The titanium dioxide pigment used in the practice of the present invention is, of course,
If necessary, various organic treatments with triethanolamine, trimethylolpropane, fatty acid metal salts, organoborisiloxane, etc. may be performed.

Polyolefin resins used in the practice of the present invention include homopolymers such as polyethylene, polypropylene, polybutene, and polypentene, and copolymers made from two or more α-olefins such as ethylene-propylene copolymers and ethylene-butylene copolymers. Among these, polyethylene resins are preferred from the viewpoint of melt extrusion coating properties and economic efficiency. These polyethylene resins include low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, copolymers of ethylene and α-olefins such as propylene and butylene, carboxy-modified polyethylene, etc. It is a mixture and can have various densities, melt flow rates (hereinafter simply referred to as MFR), molecular weights, and molecular weight distributions, but it usually has a density of 0. 90 g/cm
” ~0.97g/CIn3 range, MFR1
g/10 minutes to 30 g/10 minutes, preferably MFR3 g/10 minutes
10 minutes ~1. 5 g/min and molecular weights ranging from 20,000 to 250,000 can be advantageously used alone or in combination. In addition, if the resin has a multilayer structure, the outermost layer resin may have a VFR of 5 to 20 g/10 minutes, and the lower layer resin may have a MFR of 2 to Log/10 minutes. You can also use

The method for incorporating the titanium dioxide pigment used in the practice of the present invention into the resin layer of the resin-coated paper-type photographic support is to prepare a so-called masterbatch in which the titanium dioxide pigment is previously contained in a polyolefin resin at a constant concentration. Either use a resin composition in which they are diluted and mixed with a diluted resin to a desired ratio, or create and use a so-called compound in which a titanium dioxide pigment is initially contained in a polyolefin resin at a desired AI ratio. It is normal to do so. Banbury mixers, kneaders, kneading extruders, two-roll kneading machines, three-roll kneading machines, etc. are usually used to produce these masterbatches and compounds, but Banbury mixers and kneading extruders are advantageously used. used. Further, two or more types of these various crosstalk devices may be used in combination.

In addition, in order to improve the releasability during the production of the resin-coated paper-type photographic support of the present invention, fatty acid metal salts are added at the time of preparing the titanium dioxide pigment masterbatch or compound. Preferably, a fatty acid metal salt is contained in the resin layer of the resin-coated paper. Examples of these fatty acid metal salts include zinc stearate, calcium stearate, aluminum stearate, magnesium stearate, zirconium octylate, sodium palmitate, calcium palmitate, and sodium laurate.

The amount added is in the range of 0.1% to 50% by weight for the titanium dioxide pigment, and 0.01% to 5% by weight for the resin layer containing the titanium dioxide pigment. A range is preferred.

The content of titanium dioxide pigment contained in the resin layer of the resin-coated paper-type photographic support in the present invention is 7% by weight or less based on the resin, and the sharpness of the printed image can be improved as a photographic support. On the other hand, if it exceeds 35% by weight, the fluidity decreases and the extrusion characteristics deteriorate,
It is undesirable because the occurrence of die lip stain becomes noticeable, and a particularly preferable range is 9% by weight to 30% by weight.

On the other hand, bis(
Specific examples of the benzoxazolyl) naphthalene fluorescent agent or the bis(benzoxazolyl)stilbene fluorescent agent having a substituent include those represented by the following formula. In the case of naphthalene-based fluorescent agents, those having a substituent having 06 or more carbon atoms are preferred from the viewpoint of bleed-out resistance.

(Left below) (1) Hl? C8 (n)82sC+2 H. C (blank below) In addition, as a method of incorporating these fluorescent agents into a polyolefin resin composition, when producing a masterbatch or compound of titanium dioxide pigment, adding a fluorescent agent to the titanium dioxide pigment, A masterbatch or compound consisting of a fluorescent agent, a polyolefin resin, and a dispersant such as a fatty acid metal salt can be prepared and incorporated into the resin composition.

In addition, a fluorescent agent master is prepared by dispersing a fluorescent agent premixed with a low molecular weight polyolefin that has a softening point lower than the main polyolefin resin and is solid at room temperature or/and a dispersant, such as a fatty acid metal salt, into the main polyolefin resin. The batch can be prepared and incorporated into the resin composition. In addition, the content of the fluorescent agent in the resin composition should be 0.0000. 3mg/rIl
It is in the range of f~30mg/d. 0. 3 mg
If it is less than /rrr, the appearance of whiteness will be extremely insufficient, and if it is more than 30 sq/d, the tendency for die lip stains to occur will be undesirable. Particularly preferably 0.
It is in the range of 5 mg/rrf to 10 mg/m2.

Various types of colored pigments or dyes can be used in the practice of the present invention, including inorganic or organic blue pigments or dyes, and inorganic or organic magenta pigments or magenta dyes. preferable.

Specific examples of these include blue-based inorganic coloring compounds such as cobalt blue, navy blue, and ultramarine, and blue-based organic coloring compounds such as cerulean blue, phthalocyanine blue, and chromophthal blue A3R, and magenta inorganic coloring compounds. Examples of magenta-based organic coloring compounds include cobalt violet, fast violet, and reddish ultramarine, and examples of magenta-based organic coloring compounds include quinacridone red. In addition, the amount of the blue coloring compound added is 0.025% to 0.5% by weight, preferably 0.05% by weight in the case of a blue inorganic coloring compound, based on the resin layer. ~0.2% by weight, and in the case of blue-based organic coloring compounds, o. ooi weight%~0
．． 1% by weight, preferably in the range 0.025% to 0.05% by weight. In addition, the amount of the magenta coloring compound added is 0.025% to 1.0% by weight in the case of a magenta inorganic coloring compound to the resin layer;
Preferably 0.05% to 0.4% by weight, and in the case of a magenta organic coloring compound, 0.001% to 0.4% by weight.
03% by weight, preferably 0.002% to 0.015% by weight
% by weight. If the amount added is too small, no coloring effect will be obtained, and if it is too large, not only will the brightness decrease, but the formation of dye lip stains will become extremely noticeable, which is not preferable.

The resin layer of the resin-coated paper-type photographic support of the present invention preferably contains an antioxidant in order to more effectively prevent the occurrence of gripp stains during the production of the photographic support. Various antioxidants such as phenol-based, amine-based, or phosphoric acid ester-based antioxidants can be used as long as they do not cause any damage when applied to photographic resin compositions. Hindered phenol antioxidants are particularly preferred because they do not adversely affect the emulsion layer and can more effectively prevent grip stains. Examples of the hindered phenolic antioxidants that are advantageously used include 1. 3.
5-trimethyl-2. 4. 6-tris(3,5
-di-tert-butyl-4-hydroxybenzyl)benzene, tetrakis[methylene (3,5-di-IHt-
Butyl-4-hydroxyhydrocinnamate)] Methane, octadecyl 3.5-di 1e + 4-butyl-4-
Hydroxyhydrocinnamate, 2.2” 2'
-}Lis[(3,5-ditel1-butyl-4-hydroxyphenyl)propionyloxy]ethyl isocyanurate, 1.3,5-tris(4-tent-butyl-3-hydroxy-2,6-dimethylbenzyl) ) isocyanurate, tetrakis(2,4-dite1t-butylphenyl)4.4''-biphenylene diphosphite, 4,4-thiobis(6je+t-butylphenyl)
-cresol), 2,2--thiobis-(6 = ter
+-butyl-4-methylphenol), tris(2-
Methyl-4-hydroxy-5-1ert-butylphenyl)butane, 2,2'-methylene-bis-(4-methyl-
6-tart-butylphenol), 4,4=-methylene-bis-(2,6-dijert-butylphenol), 4,4'-butylidenebis(3-methyl-5-t
ent-butylphenol), 2.6-ditent-
Butyl-4-methylphenol, 4-hydroxy methyl-2,6-te[-butylphenol, 2,6-
G-tcr! Examples include -4-n-butylphenol. Furthermore, two or more kinds of antioxidants may be used in combination depending on the properties of the antioxidants.

The content of the antioxidant in the photographic resin composition is in the range of 5 to 1000 ppm by weight, preferably in the range of 10 to 500 ppm, and more preferably in the range of 20 to 500 ppm. ~300 ppm. Even if the amount of antioxidant is less than 5 pan,
001111ff! If it is more than 1000 ppm, die lip stains are likely to occur, and if it is more than 1000 ppm, the adhesion between the base paper and the resin layer will deteriorate, which is not preferable. In addition, as a method for incorporating an antioxidant into the resin composition, a custom compound containing the antioxidant in advance in the polyolefin resin to be used may be used, or a relatively high concentration of antioxidant may be used. An appropriate amount of the resin containing the antioxidant may be used, or the antioxidant may be added when producing the resin composition using a kneader. Furthermore, depending on the type and content of the antioxidant used, the above methods may be combined as appropriate.

The resin-coated paper-type photographic support in the present invention is a resin coated with a titanium dioxide pigment, a fluorescent agent, and a coloring pigment or a coloring dye, and more preferably a fatty acid metal salt and an antioxidant as described above. However, if the resin layer has a multilayer structure, the resin layer other than the resin layer in the present invention may also contain the above-mentioned titanium dioxide pigment, fluorescent agent, colored pigment or colored dye, fatty acid metal salt. , an antioxidant may be included. In addition, in the resin layer on the side on which the image is formed and the resin layer on the opposite side of the photographic support in the present invention, the titanium dioxide pigment, fluorescent agent, colored pigment or colored dye, fatty acid metal salt, In addition to antioxidants, titanium dioxide, zinc oxide,
White pigments such as talc and calcium carbonate, fatty acid amides such as stearic acid amide and arachidic acid amide, organic silicone compounds such as polyorganosiloxane, Tinuvin 320, Tinuvin 326, Tinuvin 328 (all Ciba-Geigy product names) It is preferable to add various additives such as ultraviolet absorbers in appropriate combinations.

The photographic support produced according to the present invention is produced by the so-called extrusion coating method, in which heated and molten polyolefin resin is cast onto a moving substrate such as paper, laminated paper, or film, and usually both sides of the support are coated with resin. Ru. In the case of a multilayer construction, several resin layers of the photographic support are extrusion coated one after another, preferably in succession, in a so-called tandem extrusion coating system, or several resin layers are extrusion coated simultaneously. Preference is given to using so-called co-extrusion coating systems.

Further, before coating the substrate with the resin, it is preferable to subject the substrate to an activation treatment such as a corona discharge treatment or a flame treatment. The surface on the emulsion side of the photographic support is a glossy surface, or a finely rough or matte surface as described in JP-A-55-26507, which does not affect the gloss of the surface of the photographic paper when it is made into photographic paper.
It has a grained surface, etc., and the back surface is usually a matte surface, and the front surface or both the front and back surfaces can be subjected to activation treatment such as corona discharge treatment or flame treatment if necessary. Further, after the activation process, a subbing process as described in JP-A-61-84643 can be performed.

The thickness of the resin layers on the front and back sides of the resin-coated paper-type photographic support is not particularly limited, but it is generally advantageous to extrusion coat the resin layer to a thickness of about 0 to 50 microns.

Substrates used in the practice of the present invention include natural pulp paper containing ordinary natural pulp as a main component, mixed paper consisting of natural pulp and synthetic fibers, synthetic fiber paper containing synthetic fibers as a main component, Either so-called synthetic paper made of polystyrene, polypropylene, or other hewei resin films, or films made of cellulose acetate, polyethylene terephthalate, polycarbonate, etc., may be used, but as a substrate for photographic paper supports, the effects of the present invention, In other words, natural pulp paper (hereinafter simply referred to as base paper) is used because it can economically advantageously provide an excellent photographic support with high print image sharpness, no dye lip streaks, and good surface quality. ) are particularly preferred and advantageously used.

Examples of the pulp constituting the base paper preferably used in the practice of the present invention include JP-A-58-37642 and JP-A-60-37642.
No. 67940, JP-A-60-69649, JP-A-61
It is advantageous to use appropriately selected natural pulps such as those described or exemplified in No. 35442.
If necessary, Hewei pulp and synthetic fibers other than natural pulp may be used. Natural pulp has been subjected to conventional bleaching treatments such as chlorine, hypochlorite, and chlorine dioxide bleaching, as well as alkali extraction or alkali treatment and, if necessary, oxidative bleaching treatment using hydrogen peroxide, oxygen, etc., and combinations thereof. Wood pulps such as softwood pulp, hardwood pulp, and softwood hardwood mixed pulp are advantageously used, and various pulps such as kraft pulp, sulfite pulp, and soda pulp can also be used.

The base paper preferably used in the practice of the present invention can contain various sizing agents and polymer compounds when preparing the paper stock slurry.

Sizing agents that can be advantageously included in the base paper preferably used in the practice of the present invention include fatty acid metal salts and/or
and fatty acids, alkyl ketene dimers, alkenyl or alkyl succinic anhydrides, JP-A-54-147211
Epoxidized higher fatty acid amide described in JP-A No. 1987-
Examples include organic fluoro compounds described in No. 109343.

Sizing agents which are preferably incorporated into the base paper used in the practice of the present invention include fatty acid metal salts that are fixed to the pulp with water-soluble aluminum salts such as aluminum chloride, aluminum sulfate, and polyaluminum chloride. Alternatively, an alkyl ketene dimer or a combination sizing agent of an alkyl ketene dimer and an eboxidized higher fatty acid amide can be mentioned, which is fixed to the pulp with or without using a fatty acid and a water-soluble aluminum salt. The fatty acid metal salt and/or fatty acid preferably have 12 to 22 carbon atoms,
The amount added is preferably in the range of 0.5 to 4.0% by weight based on the absolute dry weight of the pulp.

In addition, the amount of water-soluble aluminum salt added as needed is 1/20 to 4 times the solid weight of the sizing agent.
The range of /1 is particularly preferred, and the range of 1/10 to 1/1 is particularly preferred. Further, the alkyl ketene dimer has an alkyl group having 8 to 30 carbon atoms, preferably 12 to 18 carbon atoms. Alkyl ketene dimers are usually commercially available as emulsions thereof, and specific examples include Acopel 360XC manufactured by Dick Hercules. The amount added is preferably in the range of 0.2 to 4.0% by weight based on the absolute dry weight of the pulp as the alkyl ketene dimer content.

Examples of polymer compounds that can be advantageously incorporated into the base paper preferably used in the practice of the present invention during the preparation of the paper stock slurry include cationic wet paper strength agents, cationic, anionic or amphoteric paper strength agents. As the cationic wet paper strength enhancer, polyamine polyamide resin is preferable, and the amount added is in the range of 0.05 to 4.0% by weight, especially 0.15% by weight based on the dry weight of the pulp.
A range of 1.5% by weight is preferred. Specific examples include Kaimen 557H, Kaimen S-25, and Evinox P-1130 manufactured by Dick Hercules.

Examples of cationic, anionic or amphoteric paper strength enhancers include cationic starch described or exemplified in Japanese Patent Publication No. 60-17103, cationic polyvinyl alcohol described or exemplified in Japanese Patent Application No. 62-49699, No. 57-185432, Japanese Unexamined Patent Publication No. 57-19
7'5 3 9, anionic polyacrylamide described or exemplified in Japanese Patent Publication No. 62-231.19, Japanese Patent Publication No. 62-31118, Japanese Patent Publication No. 61-37613, Examples include amphoteric polyacrylamide described or exemplified in JP-A No. 5931949, and vegetable galactomannan described or exemplified in JP-A-59-125731. The amount of these additives is 0.000% based on the dry weight of the pulp.
A range of 0.05 to 8% by weight is particularly preferred, particularly a range of 0.15 to 4% by weight.

In addition, the base paper preferably used for carrying out the present invention includes:
Various additives can be included when preparing the paper stock slurry. Fillers include clay kaolin, calcium carbonate, barium sulfate, magnesium silicate, titanium oxide, etc. pH regulators include caustic soda, soda carbonate, etc.
As a coloring pigment, a coloring dye, and a fluorescent whitening agent, JP-A-54-
No. 147033, patent application No. 1983-37555, patent application No. 1983
The materials described or exemplified in No. 3-96516 may be contained in appropriate combinations.

Various water-soluble polymers, antistatic agents, and additives can be added to the base paper preferably used in the practice of the present invention by spraying or tab size pressing. Water-soluble polymers include starch-based polymers, polyvinyl alcohol-based polymers, gelatin-based polymers, polyacrylamide-based polymers, and cellulose-based polymers as described or exemplified in Japanese Patent Application No. 63-96516. Alkali metal salts such as sodium chloride and potassium chloride as described or exemplified in the No.
Alkaline earth metal salts such as calcium chloride and barium chloride, colloidal metal oxides such as colloidal silica, organic antistatic agents described or exemplified in JP-A-58-82242, latexes, emulsions, petroleum resins, etc. Emulsion, latex such as styrene-acrylic acid monoacrylate copolymer, styrene-acrylic acid monobutadiene copolymer, ethylene-vinyl acetate copolymer, styrene-maleic acid monoacrylate copolymer,
Pigments include clay, kaolin, talc, barium sulfate, titanium oxide, etc. pH regulators include hydrochloric acid, phosphoric acid,
It is advantageous to contain a suitable combination of citric acid, caustic soda, soda carbonate, and other additives such as the above-mentioned color pigments, color dyes, and fluorescent whitening agents.

For the production of the base paper preferably used in the practice of the present invention, commonly used paper machines such as a Fourdrinier paper machine and a circular net paper machine are used.
It is advantageous to employ suitable papermaking methods, such as those described or exemplified in JP-A-60240 and JP-A-61-284762.

There are no particular restrictions on the thickness of the base paper, but after making the base paper,
Preferably, the base paper is calendered as described or exemplified in No. 6397, and its basis weight is 40 g/
i~250g/rrf is preferred.

The photographic support in the present invention can be coated with various back coat layers for antistatic purposes, curl prevention, and the like. In addition, for the back coat layer,
No. 20, Special Publication No. 57-9059, Special Publication No. 57-539
No. 40, Japanese Patent Publication No. 58-56859, Japanese Patent Publication No. 59-21
Inorganic antistatic agents, organic antistatic agents, hydrophilic binders, latexes, curing agents, pigments, surfactants, etc. described or exemplified in No. 4849, JP-A No. 58-184144, etc. can be contained in appropriate combinations. .

The photographic support in the present invention is coated with various photographic constituent layers, and is used for color photographic paper, black and white photographic paper, typesetting photographic paper, copying photographic paper, reversal photographic material, silver salt diffusion transfer. It can be used for various purposes such as method positives and printing materials. For example, silver chloride, silver bromide, silver chlorobromide, silver iodobromide,
A silver chloroiodobromide emulsion layer can be provided. A color coupler can be included in the silver halide photographic emulsion layer to provide a multilayer silver halide color photographic structure layer.

Further, a silver salt diffusion transfer image-receiving layer can be provided by containing physical development nuclei. As the binder for these photographic structure layers, in addition to ordinary gelatin, hydrophilic polymeric substances such as polyvinylpyrrolidone, polyvinyl alcohol, and polysaccharide sulfate ester compounds can be used. Also,
The photographic structure layer described above can contain various additives, such as cyanine dyes, merocyanine dyes, etc. as sensitizing dyes, water-soluble gold compounds, sulfur compounds, etc. as chemical sensitizers, and antifogging agents. As agents or stabilizers, hydroxy monotriazo-pyrimidine compounds, mercapto heterocyclic compounds, etc., as hardening agents, formalin,
Vinyl sulfone compounds, aziridine compounds, etc. as coating aids, benzene sulfonate, sulfosuccinate salts, etc., anti-staining agents, dialkylhydroquinone compounds, etc. In addition, fluorescent whitening agents, sharpness-enhancing dyes, antistatic agents, A pH adjuster, a fogging agent, and further a water-soluble iridium, a water-soluble rhodium compound, and the like can be contained in an appropriate combination during the production and dispersion of silver halide.

The silver halide photographic material according to the present invention can be used for exposure, development, and stopping as described in "Photographic Light-sensitive Materials and Handling Methods" (Kyoritsu Shuppan, written by Goro Miyamoto, Photographic Technology Course 2) according to the photographic material. , fixing, bleaching, stabilization, etc. Multilayer silver halide color photographic materials that undergo one-bath bleach-fixing treatment after color development are particularly known as CD-Ill, CD-Ill.
It can be processed with any crude drug color developer such as IV (the above two compounds are trade names of Kodak Co.) and droxychrome (trade name of May and Baker Co.).

A developing solution containing such a main agent may contain a development accelerator such as benzyl alcohol, thallium salt, or phenidone, or it is also possible to process with a developing solution that does not substantially contain benzyl alcohol. Also, useful one-bath bleach-fix solutions are solutions of metal salts of aminobocarboxylic acids (e.g., ferric complex salts such as ethylenediaminetetraacetic acid, propylenediaminetetraacetic acid, etc.), and fixing agents include sodium thiosulfate, thiosulfate, etc. Ammonium sulfate and the like are useful. Such a one-bath bleach-fix solution may contain various additives. For example, desilvering accelerators (e.g., U.S. Pat. No. 3,51
2.979, mercapto heterocyclic compounds described in Belgian Patent No. 682.426), antifouling agents, pH adjusting agents or pH buffering agents, hardening agents (e.g. magnesium sulfate, sulfuric acid Various compounds such as aluminum, potassium alum, etc.), surfactants, etc. can be contained in combination. Also, such one-bath bleach-fix solutions can be used at various pH values, but a useful pH range is from pH 6.0 to pH 8.0.

〔Example〕

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

Example 1 A rutile type titanium dioxide pigment manufactured under predetermined firing conditions to obtain the particle size listed in Table I according to the manufacturing process of rutile type titanium dioxide pigment by the sulfuric acid method described in the main text of the specification. The titanium dioxide linker was pulverized and sized, and further wet-pulverized and classified to obtain a titanium dioxide slurry substantially free of coarse titanium dioxide. This slurry was placed in a reaction treatment tank, the pH of the slurry was raised to about 9.2 with sodium hydroxide, and the temperature of the slurry was heated to about 70°C. An amount of sodium aluminate aqueous solution calculated to be 0.75 wt. or 1.9 wt.% was added and held for 30 minutes.

The pH of the slurry was then adjusted to 7.0 by adding 20% sulfuric acid.
The slurry was further aged for 2 hours. After ripening,
The initial mother liquor of the titanium dioxide slurry surface-treated with hydrous alumina is filtered through a filter press, and the titanium dioxide cake in the filter press is then washed with running water to form a suspension as defined in the text of the specification for titanium dioxide pigments. It was washed with water under predetermined washing conditions until the electrical conductivity was 45 μt5/cm.

After that, the titanium dioxide cake was dried, impact-pulverized in a hammer mill with a quantitative feeder, and further finely pulverized in a steam mill to produce rutile-type titanium dioxide pigments with different particle sizes whose particle surfaces were treated with different amounts of hydrated alumina. were manufactured respectively.

Thus, the density is 0. 9 1 8 g/cm", M
Low density polyethylene 5 with F R of 8.0 g/10 min
0 parts by weight, 50 parts by weight of the above titanium dioxide pigment, and 2.5 parts by weight of zinc stearate were thoroughly kneaded at 150'C using a Banbury mixer to prepare masterbatches of titanium dioxide pigments.

Next, the fluorescent agent (IX) described in the main text of the specification 0.28
parts by weight and 0.28 parts by weight of zinc stearate were thoroughly mixed in advance, and the mixture was mixed with the same low-density polyethylene 40 as used for preparing the titanium dioxide pigment masterbatch described above.
Parts by weight were thoroughly kneaded at 135°C using a Labo Plastomill to prepare a fluorescent agent masterbatch.

In addition, 50 parts by weight of Hoster Palm Pink E and Sunwax 171-P (polyethylene wax molecular weight approximately 1500
, softening temperature: 105° C.) were melt-kneaded in a heating furnace and further dispersed in a heated three-roll mill to obtain a colored premix in the form of flakes. The mixture 0. 2 parts by weight 50 parts by weight of the same low density polyethylene used to prepare the titanium dioxide pigment masterbatch described above, 50 parts by weight of the titanium dioxide pigment described above and 2.5 parts by weight of zinc stearate.
The weight parts were thoroughly mixed at 150° C. using a Banbury mixer to prepare titanium dioxide pigment masterbatches containing quinacridone pigments.

Furthermore, 50 parts by weight of the same low-density polyethylene as used in the preparation of the titanium dioxide pigment masterbatch, 50 parts by weight of the above titanium dioxide pigment, ultramarine blue (manufactured by Daiichi Kasei Kogyo Co., Ltd., #2000)1. ．． 25 parts by weight and 2.5 parts by weight of zinc stearate were mixed into 1 part by weight using a Banbury mixer.
The mixture was thoroughly kneaded at 50° C. to prepare a titanium dioxide pigment masterbatch containing ultramarine blue.

On the other hand, a mixed stock of 50 parts by weight of bleached hardwood kraft bulp and 50 parts by weight of bleached softwood sulfite pulp was beaten to 310 ml of Canadian Standard Freeness, and 3 parts by weight of cationized starch was added to 100 parts by weight of the pulp. 0.2 parts by weight of anionized polyacrylamide, 0.4 parts by weight of alkyl ketene dimer emulsion (as ketene dimer content), 0.4 parts by weight of polyaminopolyamide Epicorhydrin resin. Added 4 parts by weight, basis weight 1 6
0 g/rd paper was produced. The obtained wet paper was heated to 110
℃, followed by 3 parts by weight of carboxy-modified polyvinyl alcohol, 0.05 parts by weight of fluorescent brightener, 0 parts by weight of blue dye.
．． 002 parts by weight, 0.2 parts by weight of citric acid, and 97 parts by weight of water at 25 g/r+{impregnated at 110°C.
After drying with hot air and supercalendering at a linear pressure of 90 kg/0, both surfaces were subjected to corona discharge treatment to produce a base paper for a resin-coated paper-type photographic support.

Next, coat the back side of the base paper with high-density polyethylene (density 0.96
0 g/an3, MFR = 5 g/10 min and low density polyethylene (density 0.923 g/an3, MFR
= 5g/10 min) was coated to a thickness of 30μ using a melt extrusion coater at a resin temperature of 330°C. Next, the above-mentioned titanium dioxide pigment masterbatch, ultramarine-containing titanium dioxide pigment masterbatch, fluorescent agent masterbatch, titanium dioxide pigment masterbatch containing quinacridone pigment, and high-density polyethylene (density 0.9 70 g
/an3, MFR7.0g/10min) 20 parts by weight and low density polyethylene (density 0.920g/an3
, MF R 6. 0 g / 10 minutes) 49 parts by weight (54 parts by weight if no fluorescent agent masterbatch is added) with the formulation listed in Table 1 was melted to a thickness of 30 μ at a resin temperature of 320°C. By extrusion coating, polyethylene resin-coated paper-type photographic supports of the present invention and outside the present invention were produced, respectively. At this time, the surface of the polyethylene containing the titanium dioxide pigment was processed into a completely flat glossy surface, and the surface quality of the polyethylene on the back was processed into a paper-like matte surface.

The whiteness of the appearance of the titanium dioxide pigment-containing side of the polyethylene resin-coated paper-type photographic support thus obtained was visually evaluated. As an evaluation standard, it is very white→◎
, white → ○, slightly yellow → △, yellow → ×.

In addition, die lip stain was measured as follows.

Using a screw extruder with an extrusion opening diameter of 65 mm and a melt extruder with a T-die of 750mm width, the melting temperature was 320°C.
After melt extrusion for 2 hours at a screw rotation speed of 10 rpm, the number of stains generated on the grip was counted and measured.

Next, in order to measure the sharpness of printed images, color photographic paper having the above photographic support was produced. First, 0.4 g of a back coat layer having a composition of colloidal silicone: styrene acrylic latex = 1 = 1 was applied to the back side of the photographic support after corona discharge treatment as a dry weight component.
/r1! Painted.

Next, on the front resin surface containing the titanium dioxide pigment of the photographic support, after Kona discharge treatment, a blue-sensitive emulsion layer containing a yellow color-forming coupler, an intermediate layer containing a color mixing preventive agent, and a green-sensitive emulsion layer containing a magenta color-forming coupler are applied. A color photographic paper was obtained by providing a layer, an ultraviolet absorbing layer containing an ultraviolet absorber, a red-sensitive emulsion layer containing a cyan color-forming coupler, and a protective layer. Each color-sensitive emulsion layer was coated with silver nitrate at 0.0.
Contains silver chlorobromide equivalent to 6 g/rrf, and also contains gelatin necessary for silver halide production, dispersion, and film formation, as well as appropriate amounts of antifoggants, sensitizing dyes, coating aids, hardeners, and thickeners. Contains sticky agent and appropriate amount of filter dye.

A resolution kachart was adhered to the resulting photographic paper, exposed to green light, and subjected to color development to obtain a test sheet. Measure this test sheet with a microdensitometer,
CTF (Conlra +
tTransfer Function (contrast transfer function) was determined to determine the sharpness of the printed image on the photographic support. In addition, the larger the value of CTF,
This shows that the sharpness of the printed image is high.

The results obtained are shown in Table 1.

(Margin below) As can be seen from Table 1, titanium dioxide pigment is present in the resin layer of the resin-coated paper-type photographic support on the side where the image is formed, and its particle diameter is determined by the number average diameter determined by an electron microscope. Displayed, it is in the range of 0.110 μm to 0.150 μm,
and its surface has a titanium dioxide pigment and substituents treated with hydrous aluminum oxide in an amount ranging from more than 0.2% by weight to less than 1.9% by weight calculated in the form of A#203 per titanium dioxide. The photographic support of the present invention containing a bis(benzoxazolyl)stilbene fluorescent agent and a colored pigment (Samples Na8 to Na9, Na12 to Na
13) is an excellent photographic support with high sharpness of the printed image, high brightness and white appearance, and extremely little generation of die lip stains during production of the photographic support, resulting in good surface quality. It turns out that it is a body. In particular, photographic supports that use both blue and magenta colored pigments in the resin layer (Samples Nα9, M13)
It can be seen that the whiteness of the appearance is excellent.

On the other hand, photographic supports other than the present invention (Nα1 to Nα7, Nα
10 to Nα11 and Nα14 to Nα19) are found to have problems, respectively.

That is, the titanium dioxide pigment in the resin layer has a particle size of 0.
Photographic supports (samples Nα1 to Na 3 ) containing particles with a diameter of less than 110 μm tend to have a high occurrence of die lip stains and the sharpness of printed images tends to be low. The resin layer containing neither coloring pigment nor fluorescent agent (sample 1) tends to have a lower occurrence of gripp stains, but only a product with an extremely poor white appearance can be obtained. On the other hand, it can be seen that those containing titanium dioxide pigments having a particle size larger than 0.150 μm (Samples No. 17 to Nα19) have a problem in that the sharpness of the printed images is low.

In addition, the particle size in the resin layer is 0.110 μm to 0.150 μm.
Even if a photographic support contains a titanium dioxide pigment in the μm range, it contains a titanium dioxide pigment in which the amount of treatment of the titanium dioxide particle surface with hydrous aluminum oxide is 1.8% by weight or more. Case (sample fish 14 ~ NcL1
In case 6), the generation of dye lip stains is extremely high, which is a problem, and on the other hand, when the treatment amount contains titanium dioxide pigment of 0.2% by weight or less (sample Nα4), titanium dioxide pigment There is an increase in the occurrence of minute foreign particles or particles called microgrit on the resin surface containing
CL type) had a problem in that the sample surface turned yellow after irradiation for 120 hours. Furthermore, when the resin layer does not contain a fluorescent agent and a coloring pigment (sample magnetic 5 to NQ7, black 10 to Nα11)
It can be seen that only extremely poor white appearance can be obtained.

Example 2 The same procedure was carried out except that a titanium dioxide pigment having a particle size expressed by the number average diameter in directional measurement using an electron microscope listed in Table 1 was used instead of the titanium dioxide pigment used in sample Nα13 of Example 1. It was carried out similarly to sample Nal3 in Example 1.

The results obtained are shown in Table 2.

(Margins below) As can be seen from Table 2, titanium dioxide pigment is present in the resin layer of the resin-coated paper-type photographic support on the side where the image is formed, and its particle size is determined by directional measurement using an electron microscope. 0.1-10μm to 0.150μm expressed as number average diameter
The photographic supports of the present invention containing titanium dioxide pigments (Samples 1th22 to Nα26) have high sharpness of printed images and less occurrence of die lip stains during production of the photographic supports, and therefore It can be seen that it is an excellent photographic support with good surface quality and a white appearance. In particular, the particle size is between 0.1.15 μm and 0.135 μm.
The photographic support (Samples NFL23 to N (L25)) containing a titanium dioxide pigment of μm in the resin layer had particularly high print image sharpness and very little dye lip staining, and was particularly excellent. I can see that it is something.

On the other hand, a resin layer containing titanium dioxide pigment having a particle size smaller than 0.110 μm (sample Nα20
~Na21) has extremely high occurrence of die lip stains,
The sharpness of the printed image is also low.

In addition, those containing titanium dioxide pigment with a particle size larger than 0.150 μm in the resin layer (sample barrier 27
~N (128) is found to be problematic because the sharpness of the printed image is low.

Example 3 Tetrakis[methylene (3,5-di-tert-butyl-4-hydroxy) was added as an antioxidant to the low-density polyethylene resin for masterbatches used in sample NllLl3 of Example 1 as a low-density polyethylene resin for masterbatches. The test was carried out in the same manner as Sample Nα13 of Example 1, except that methane (seahydrocinnamate) was mixed in advance in the amount shown in Table 3.

The results obtained are shown in Table 3.

(Left below) As understood from Table 3, by incorporating an antioxidant into the resin layer of the resin-coated paper-type photographic support,
It can be seen that the occurrence of gui-lip stains is well prevented.

Its content is 10 to 150% based on the resin composition.
A range of 0 ppm is preferred, especially 20 to 1000 ppm
It can be seen that the range of is preferable. The photographic support of the present invention containing an appropriate amount of antioxidant as described above is
It can be seen that this is an excellent photographic support with high sharpness of printed images, very little staining of the die lip during manufacture of the photographic support, and therefore good surface quality.

Example 4 Instead of the titanium dioxide pigment used in Example 3, the particle size expressed as the number average particle size in directional measurement using an electron microscope was 0.124 μm, and the particle surface was coated with various types and amounts. Sample Nα of Example 3, except using the titanium dioxide pigment described in Table 4 treated with a hydrous metal oxide.
It was carried out in the same manner as in 33.

At that time, titanium dioxide pigments surface-treated with various types and amounts of hydrous metal oxides were prepared as follows.

A titanium dioxide slurry obtained in the same manner as in Example 1 was placed in a reaction treatment tank, the p[{ of the slurry was raised to about 9.2 with sodium hydroxide, the temperature of the slurry was heated to about 70°C, and then the dry standard of titanium dioxide, Al203
Alternatively/and an aqueous sodium aluminate solution or/and an aqueous sodium silicate solution in the weight percentages listed in Table 4, calculated in the form of SiO2, were added and held for 30 minutes.

In addition, when performing surface coating treatment with hydrous titanium oxide, before raising the pH of titanium dioxide slurry with sodium hydroxide, add Tie2 to dry standard titanium dioxide.
An amount of an aqueous titanyl sulfate solution was added to give the weight percent shown in Table 4, calculated as follows. Thereafter, in the same manner as in Example 1, the rutile type titanium dioxide pigments listed in Table 4 were produced.

The results obtained are shown in Table 4.

As can be seen from Table 4, as the titanium dioxide pigment in the resin layer of the resin-coated paper-type photographic support, the surface thereof is more than 0.2% by weight in the form of anhydrous metal oxide per titanium dioxide;
Contains at least aluminum atoms in an amount less than 1.8% by weight and has a silicon dioxide content of 0. Photographic support in the present invention using a titanium dioxide pigment treated with 4% by weight or less (including O) of a hydrous metal oxide (sample k3)
8 to Nα45) is an excellent photographic support that has high sharpness of printed images, looks white, and produces very little die lip stain during manufacturing of the photographic support, and therefore has good surface quality. It can be seen that it is.

In addition, from the viewpoint of preventing the occurrence of die lip stains, hydrated alumina is preferable as a surface treatment agent for titanium dioxide.
In addition, the processing amount is AA+ per titanium dioxide,
It is understood that a range of 0.4% to 1.25% by weight in the form of 03 is preferred.

On the other hand, photographic supports other than the present invention (samples Nα46 to Na5
It can be seen that 0) each have their own problems. In other words, is the surface of the titanium dioxide pigment carbon dioxide? When using a surface treated with 1.8% by weight or more of hydrated metal oxide in the form of anhydrous metal oxide per tongue (sample Nα47, Nn4
9) and 0.5% by weight in the form of StO■ per titanium dioxide
When using the above surface-treated silicon oxide (samples Nα48 and N(L50), the occurrence of grip stains was significant. In addition, the surface of the sample Nα48 and N(L50) was found to be 0.2% in the form of anhydrous metal oxide per titanium dioxide. When using a surface treated with 2% by weight or less of hydrated metal oxide (sample Nα46),
The problem was that the light resistance was poor.

Example 5 Antioxidant used in Example 3 Tetrakis [methylene (3
, 5-ditell-butyl-4-hydroxyhydrocinnamate)] Instead of methane, octadecimal-
3,5-G t. e r I-butyl-4-hydroxy-hydrosinname-1', 2.2', 2' tris[(
Except using 3.5-di-butyl-4-hydroxyphenyl)propionyloxy]ethyl isocyanurate or 1.3.5-tris(4-te+t-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate. The same procedure as in Example 3 was carried out, and the same results as in Example 3 were obtained.

Example 6 In sample Nα33 of Example 3, the fluorescent agent [
Sample N( of Example 2) except for increasing or decreasing the content of IX)
It was carried out in the same manner as No. 116. At that time, when reducing the content of the fluorescent agent, reduce the amount of the fluorescent agent masterbatch,
A corresponding amount of the low density polyethylene used in the preparation of the masterbatch was added as diluent resin. on the other hand,
When increasing the content of fluorescent agent, in low density polyethylene corresponding to the diluted resin of sample Na33 of Example 3 (i.e., low density polyethylene corresponding to the diluted resin of sample Nllll.3 of Example 1). A masterbatch of a fluorescent agent prepared in the same manner as in Example 1 was added to the masterbatch, and the amount of low-density polyethylene for the diluent resin was reduced relative to the masterbatch.

The results obtained are shown in Table 5.

(Margin below) Table 5 As can be seen from Table 5, when the content of the fluorescent agent in the resin layer is less than 0.3 mg/rrf, the side of the photographic support on which the image is formed looks whiter. On the other hand, if the content is more than 25■/d, die lip stains tend to occur, so the preferable content is 0.3■/d.
It can be seen that it is in the range of ~25 .mu./d. As described above, the photographic support of the present invention to which an appropriate amount of fluorescent agent is added has a particularly low occurrence of gripp stains during its manufacture, and therefore has good surface quality and high sharpness of printed images. It also looks white and is an excellent photographic support.

Example 7 Fluorescent agents (I) to (■) or (X) to (XI) described in the main text of the specification are used instead of fluorescent agent (IX) used in sample Nα57 of Example 6. is sample Na5 of Example 6
It was carried out in the same manner as in 7.

As a result, an excellent photographic support similar to Sample Na57 of Example 6 was obtained.

Example 8 In place of the rutile-type titanium dioxide pigment of Example 1, the following was used to obtain the same results as in Example 1.

U.S. Patent No. 3,121.6 according to the process for producing rutile-type titanium dioxide pigment by the chlorine method described in the main text of the specification.
Using the same equipment as No. 41, the heating temperature was 1500°C during sintering and decomposition.
The amount of aluminum compound relative to the titanium tetrachloride, oxygen and titanium dioxide pigment into the combustion reaction tower is 0.15% by weight, 0.75% by weight or 1.5% by weight, calculated in the form of A#203.
Calcination decomposition is carried out by simultaneously supplying aluminum chloride so that the concentration is 9% by weight. Thereafter, it was subjected to a decomposition process, pulverized and sized using a centrifugal roller mill, and further wet-pulverized and classified to produce a titanium dioxide slurry substantially free of coarse titanium dioxide. The titanium dioxide slurry was subjected to subsequent treatments of filtration, washing, drying, and final pulverization in the same manner as in Example 1 to produce a rutile-type titanium dioxide pigment internally treated with an aluminum compound.

Example 9 Instead of the rutile titanium dioxide pigment used in Example 2,
Example 2 was carried out in the same manner as in Example 2 except that the following anatase type titanium dioxide pigment was used.

Anatase produced under hydrolysis conditions and calcination conditions predetermined to obtain the particle size listed in Table 6 in accordance with the production process of anatase-type titanium dioxide pigment by the sulfuric acid method described in the main text of the specification. A type of titanium dioxide linker was crushed and sized, and further wet-pulverized and classified to obtain a titanium dioxide slurry substantially free of coarse titanium dioxide. This slurry was placed in a reaction treatment tank, and as in Example 1, the surface was treated with 0.75% by weight of hydrated aluminum oxide, calculated in the form of AI20s, based on dry standard titanium dioxide, followed by washing and treatment. Drying and final pulverization were performed to produce anatase-type titanium dioxide pigments having different particle sizes and surface-treated with hydrous aluminum oxide.

The results obtained are shown in Table 6.

(Margin below) As can be seen from Table 6, titanium dioxide pigment is contained in the resin layer of the resin-coated paper-type photographic support on the side where the image is formed, with a particle size of 0.110 μm to 0.150 μm. The photographic support of the present invention (samples Nα63 to Nα67) contains a titanium dioxide pigment whose particle surface has been treated with a specific amount of hydrated aluminum oxide, a fluorescent agent of the present invention, and a coloring pigment. It can be seen that this is an excellent photographic support with high sharpness of printed images, white appearance, and little generation of gripp stains during production of the photographic support, and therefore good surface quality.

On the other hand, a photographic support other than the present invention (sample N (L61-46
It can be seen that 2, 468 to 69) each have their own problems.

That is, those containing titanium dioxide pigments with a particle size of less than 0.110 μm (samples Nα61 to Tane 62),
Glylip stains occur frequently, and the sharpness of printed images is also low.
It can be seen that Nα69) is a problem because the sharpness of the printed image is low.

〔Effect of the invention〕

The present invention provides an excellent resin-coated paper-type photographic support that has high print image sharpness, is visually white, and generates extremely little die lip stain during the manufacture of the photographic support, and therefore has good surface quality. I can donate my body.

Claims (9)

[Claims] (1) In a resin-coated paper-type photographic support in which at least one side of paper, synthetic paper, or film substrate is coated with a polyolefin resin composition, the polyolefin resin composition is at least (A) The particle size expressed as the number average diameter is 0.110 μm to 0.15
titanium dioxide pigment having a particle diameter of 0 μm and containing at least aluminum atoms in an amount of more than 0.2% by weight and less than 1.8% by weight, calculated in the form of anhydrous metal oxide per titanium dioxide, and a silicon dioxide content. 0.4% by weight
The surface is treated with a hydrous metal oxide of (including 0) or at least in an amount of more than 0.2% by weight and less than 1.8% by weight, calculated in the form of anhydrous metal oxide per titanium dioxide. A titanium dioxide pigment whose particle interior has been treated with an aluminum compound, (B) a bis(benzooxolyl)naphthalene-based fluorescent agent having a substituent or a bis(benzooxazolyl)stilbene-based fluorescent agent having a substituent, and (C) A photographic support characterized by containing a colored pigment or a colored dye. (2) The photographic support according to claim 1, wherein the colored pigment or colored dye is a combination of a blue pigment and a magenta pigment. (3) Fluorescent agent content is 0.3mg/m^2~30mg
3. The photographic support according to claim 1 or 2, which is /m^2. (4) The photographic support according to claim 1, 2 or 3, wherein the titanium dioxide pigment has a rutile structure. (5) Claims 1, 2, and 3, wherein the titanium dioxide pigment is 9% to 30% by weight based on the polyolefin resin composition.
or the photographic support described in 4. (6) The photographic support according to claim 1, 2, 3, 4 or 5, wherein the polyolefin resin is a polyethylene resin. (7) Claim 1, 2, 3, 4, 5 or 6, wherein the polyolefin resin composition contains a higher fatty acid metal salt.
Photographic support as described. (8) The photographic support according to claim 1, 2, 3, 4, 5, 6 or 7, wherein the polyolefin resin composition contains an antioxidant. (9) The photographic support according to claim 8, wherein the antioxidant is a hindered phenolic antioxidant.