JPH0823669B2 - Manufacturing method of photographic support - Google Patents

Description

The present invention relates to a photographic support, and more particularly to a method for producing a photographic support which is excellent in light resistance and sharpness and has very little occurrence of die lip stain.

Furthermore, the present invention relates to a method for producing a photographic support having good surface quality in which microgrit is extremely rare on the resin surface of the resin-coated paper.

Since the photographic support has been used for rapid photographic processing, for example, a so-called photographic resin coated paper in which both sides of a photographic printing paper are coated with polyolefin by extrusion coating is used, and one side thereof is used. Titanium dioxide is usually included to impart sharpness.

However, when a polyolefin resin composition containing titanium dioxide is melt-extruded into a film form from a slit die, a needle-like or icicle-like attachment or stain (hereinafter simply referred to as die-lip stain) on the tip of the die lip by short-time extrusion. However, this die lip stain tends to grow larger and larger with the lapse of the melt extrusion time.

When this die lip stain occurs during melt extrusion coating, streaks occur in the vertical direction on the surface of the photographic polyolefin resin coated paper produced as it is, and streaky unevenness occurs due to uneven coating amount. Dust, and sometimes stains adhere to the film and are coated, and foreign matter appears. Therefore, the surface quality of the produced polyolefin resin-coated paper is significantly impaired, and it becomes completely unsuitable and has no commercial value as a photographic support requiring excellent surface quality.

In addition, in order to completely remove the dirt on the die lip once, there is no other way than to stop the production and clean the die lip, which requires a lot of labor and time and causes a significant decrease in productivity. There was an urgent need for a solution.

As a result of various studies on the prevention of the die lip stain, the present inventors have found that titanium dioxide contained in the polyolefin resin composition has a serious problem. In terms of the content of titanium dioxide, when the content of titanium dioxide in the polyolefin resin is low, the occurrence of die lip stains is small, but the hiding power is small and it cannot be used as a photographic support, while the content of titanium dioxide is small. It was found that the hiding power was sufficient when the value was high, but the occurrence of stains on the die lip was remarkable.

Of course, titanium dioxide (hereinafter referred to as titanium dioxide) in the resin layer of the photographic support
(Sometimes referred to as TiO ₂ ), the sharpness is remarkably deteriorated and it cannot be used as a photographic support.

Since TiO ₂ used in the photographic industry has strict quality requirements, various surface treatment agents such as inorganic treatment such as hydrous aluminum oxide and / or silicon dioxide, and in some cases siloxane, alcohol, surface active So-called untreated TiO ₂ which has been subjected to an organic treatment such as an agent and has not been subjected to any surface treatment is hardly used. The more highly surface-treated, the more markedly the die lip stain occurs. On the other hand, when untreated TiO ₂ is used, the occurrence of die lip stain is small, but the light deterioration is remarkable, and the color easily changes over time.

To solve these problems, for example, JP-A-57-
108849 contains hydrated aluminum hydroxide of 0.2 with respect to TiO ₂ .
~ 1.2 wt% (calculated in the form of Al ₂ O ₃ ) surface treated TiO ₂
A photographic support to which is applied is disclosed. However, when the TiO ₂ content in the resin composition is considerably increased, die lip stain occurs, and there is a slight coloring property for TiO ₂ due to the impurities of the surface treatment agent, which results in whiteness. There is some dissatisfaction with the point.

The die lip stain problem and the following micro grit problem are the most important problems in the industry, and the fact is that efforts are being made to solve these problems.

The term "microgrit" as used herein refers to minute foreign matter or minute particles appearing on the surface of a coated resin in a photographic support in which at least one surface of a base paper is coated with a resin composition.

There are various causes of mictogrit. For example, as a cause of cumyloglit which appears on a photographic support produced by melt extrusion coating a resin on at least one surface of a base paper with a melt extruder, (1) Regarding the polyolefin itself used, if gel is generated frequently, (2) When the molten resin cannot be maintained at an appropriate temperature and becomes a non-uniform flow when the molten resin is extruded into a film from a die through a die,
(3) The screen attached to the breaker plate in the melt extruder is dirty, (4) There is a crack in the barrel liner in the melt extruder, (5) In the case of insufficient warpage in the melt extruder, etc. However, there are many cases where these can be relatively easily solved by a skilled engineer or the like.

However, the most difficult countermeasure against microgrit is when microgrit is generated on a photographic support whose base paper is coated with a resin composition containing at least a polyolefin and a titanium dioxide pigment.

In the first place, as a method of incorporating the titanium dioxide pigment into the polyolefin resin, is it necessary to prepare a so-called masterbatch in which the pigment is contained in the resin in a high concentration in advance, and to use them by diluting and mixing them with a diluting resin to a desired ratio? In general, a so-called compound in which a desired composition ratio is contained in a resin from the beginning is usually prepared and used.

However, when a masterbatch or compound is prepared by melt-kneading a polyolefin and a titanium dioxide pigment using a usual melt-kneader such as a Banbury mixer or a kneader, a relatively coarse titanium dioxide pigment The agglomerates tend to be dispersed as they are without being dispersed in a fine state, and, as a result, coarse pigment particles are present in the masterbatch or compound. As a result, microgrit is generated on the resin surface of the photographic support coated on at least one surface of the base paper with a resin composition composed of a pigment and a resin produced by using the masterbatch or the compound. Will be done.

The generation of microgrit on resin-coated paper as a photographic support causes serious photographic defects. That is, when a person is copied on a printing paper having a resin-coated paper in which microgrit is generated as a photographic support, if the microgrit appears in a part such as a face, the commercial value of the person is completely lost.

By the way, the pigment contained in the resin layer on the emulsion coated surface side of the resin-coated paper as the photographic support has a whiteness,
It is well known that titanium dioxide pigments are usually used because of their excellent hiding power and resolution.

However, a photographic support in which at least one surface of a base paper is coated with a resin composition comprising at least a titanium dioxide pigment and a polyolefin is produced by using a titanium dioxide pigment masterbatch or compound as described above. In that case, there has been a serious problem that microgrits due to coarse particles of the titanium dioxide pigment are likely to occur on the resin surface of the photographic support, as described above. Further, the more the content of the titanium dioxide pigment in the resin composition is, the more the microgrit tends to be generated.

The object of the present invention is to provide a photographic support which has very little occurrence of stains on the die lip, and which has very little microgrit on the coated resin surface of the resin-coated paper and which has good image quality and excellent light resistance and sharpness. To do.

That is, in the method for producing a photographic support in which at least one surface of the base paper is coated with a resin composition comprising at least a polyolefin and a titanium dioxide pigment, the resin composition is a polyolefin and a sulfuric acid method before the firing step, chlorine. In the method, an aluminum compound was added before the oxidation step so that the amount of aluminum with respect to titanium dioxide was 0.1 to 2.0% by weight calculated in the form of Al ₂ O ₃ , and then in the sulfuric acid method, it was prepared through a firing step. A method for producing a photographic support comprising a titanium pigment is provided.

The TiO ₂ used in the practice of the present invention is such that the amount of aluminum relative to the finished titanium dioxide pigment is 0.1 to 2.0 wt% calculated in the form of Al ₂ O ₃ and is less than 0.1 wt%. Deterioration is remarkable, and when it exceeds 2.0% by weight,
The color of the finished titanium dioxide pigment tends to be poor. Preferably 0.2-2.0% by weight, particularly preferably 0.2-
It is 1.2% by weight.

In the case of the sulfuric acid method, examples of the aluminum compound used for TiO ₂ in the present invention include aluminum compounds such as aluminum chloride, aluminum sulfate, aluminum hydroxide and sodium aluminate, but aluminum chloride and aluminum sulfate are preferable. In the case of the chlorine method, aluminum chloride is preferable.

The sulfuric acid method is usually performed in the following steps. Raw ore → Digestion / extraction → Standing / crystallization → Filtration / concentration → Hydrolysis → Washing →
Baking → Grinding / Sizing → Surface treatment → Washing / Drying → Finishing grinding →
Titanium dioxide pigment. The chlorine method is usually performed in the following steps. High-purity ore or synthetic rutile → chlorination → separation ・
Condensation → Purification → Preheating → Oxidation → Separation → Grinding / Sizing → Surface treatment → Washing / Drying → Finishing grinding → Titanium dioxide pigment.

In the present invention, the method of allowing aluminum to coexist in titanium dioxide is not carried out by a surface treatment by a generally used wet method or a so-called dry method in which titanium dioxide and an aluminum compound are simply mixed, but by a sulfuric acid method. In some cases, it is carried out by adding an aluminum compound before the calcination step, but a preferable step is that after hydrolysis, washing, and TiO ₂ concentrated by a filter or the like.
Is placed in a mixer, for example, a kneader, an aluminum compound is added thereto and well mixed, and then a baking step is performed.
In the case of the chlorine method, it is prepared by supplying an aluminum compound, preferably aluminum chloride, at the same time as titanium tetrachloride and oxygen during the oxidation step, using an apparatus such as that disclosed in USP 3121641.

As described above, the TiO ₂ in the present invention may be produced by either the sulfuric acid method or the chlorine method, or may be the rutile type or the anatase type or a mixed TiO ₂ thereof. In the case of the chlorine method, the rutile type is advantageously used. The particle size is also not particularly limited, but a particle size of about 0.1 to 1 μm, and a particle size of about 0.15 to 0.35 μm is advantageously used in view of hiding power.

Of course, various organic surface treatments with triethanolamine, trimethylolpropane, aliphatic metal salts, organopolysiloxane, etc. may be carried out if necessary.

When the content of TiO ₂ in the resin composition is 5% by weight or less, the hiding power as a photographic support is insufficient, and when it exceeds 40% by weight, the fluidity is lowered, which is not preferable. ~ 30
% By weight is preferred, with 9 to 25% by weight being particularly preferred. In the case of TiO ₂ used in the present invention, even if the TiO ₂ content in the resin composition is considerably increased, the occurrence of die lip stain is extremely small, and there is an advantage that a photographic support having excellent sharpness can be obtained. .

Although there are still many unclear points about the excellent effect of TiO ₂ containing aluminum used in the present invention, for example, in the case of the sulfuric acid method, the surface treatment agent and various types of surface treatment agents related thereto are used in the conventional wet aluminum hydroxide surface treatment. The impurities contained in the chemicals tend to be mixed in the titanium dioxide pigment finished in a relatively residual form, and the water introduced by the surface treatment with aluminum hydroxide oxide is also likely to remain. In the case of TiO ₂ used for
It is also considered that the removal of impurities is performed because the aluminum compound is added before firing and the firing step is performed thereafter. On the other hand, in the case of a simple dry surface treatment in which an aluminum compound and TiO ₂ are mixed and stirred,
The surface treatment is difficult to perform uniformly, and there is a drawback that only a product with quality fluctuation can be obtained.

In the present invention, usually, in both the sulfuric acid method and the chlorine method, finish pulverization is carried out by an impact pulverizer such as a hammer mill or a centrifugal roller mill such as a Raymond mill, and the finish pulverizer is a fluid energy mill such as a steam mill. If a photographic support is obtained in which the generation of microgrit is well suppressed, it is possible to obtain a photographic support which is further crushed by a conventional finishing crusher such as a hammer mill or a raymond mill and further crushed by a fluid energy mill. A photographic support whose generation is well suppressed is obtained.

The fluid energy pulverizer used in the practice of the present invention is a type of pulverizer that utilizes the energy of a high-pressure gas to accelerate particles in a stream of air at high speed, and pulverizes particles by impact between particles and between particles and walls. Although it includes an air mill and a steam mill, a steam mill utilizing the energy of heated steam is advantageously used. Of course, there is no problem in using an air mill in addition to the steam mill.

Further, before grinding, various alcohols such as trimethylolpropane, triethanolamine, various fatty acid metal salts such as sodium stearate and zinc stearate, various surfactants such as polyoxyethylene sorbitol fatty acid ester and sorbitan fatty acid ester, such as n- Butanol, n-hexanol, n-octanol, n-
It is even more effective to add various grinding aids such as decanol and various ethylene glycols alone or in combination to titanium dioxide.

The amount of the grinding aid used in the present invention varies depending on the kind of the grinding aid used, but it is usually titanium dioxide 10
0.001 to 0.05 parts by weight, preferably 0.005 to 0 parts by weight
It is 0.025 part by weight. The place of addition of these grinding aids is usually after the drying step, but is preferably just before finish grinding and / or immediately before fluid energy mill, and in the case of fluid mill such as steam mill, it is added by adding in the grinder at the time of grinding. Is preferred.

As a method of incorporating the titanium dioxide pigment used in the present invention into the resin composition of the photographic support, a so-called masterbatch in which titanium dioxide is previously contained in the polyolefin at a constant concentration is prepared, and they are diluted with a dilute resin. It is usually used by diluting and mixing it in a desired ratio, or by preparing a so-called compound in which a titanium dioxide pigment is initially contained in a polyolefin in a desired composition ratio and used. To make these masterbatches and compounds, a Banbury mixer, a kneader, an extruder for kneading, a two-roll kneader, a three-roll kneader, etc. are usually used, but a Banbury mixer and an extruder for kneading are advantageously used. To be Further, these various kneading machines may be used in combination of two or more kinds.

The polyolefin in the present invention is a homopolymer such as low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene, polybutene, polypentene or a copolymer of two or more olefins such as ethylene-propylene copolymer or ethylene. Linear low-density polyethylene, which is a copolymer of α-olefin and α-olefin, and a mixture thereof, which have various densities and melt viscosity indexes (melt index: simply abbreviated as MI hereinafter) singly or in combination. Can be used.

In the present invention, it is preferable to use low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-propylene copolymer, etc. either alone or in combination.

If desired, various additives can be added to the resin layer of the photographic support in the invention. Examples of the metal salt of a fatty acid that can be used in the present invention include zinc stearate,
Calcium stearate, aluminum stearate,
Magnesium stearate, zirconium octylate,
Examples thereof include sodium palmitate, calcium palmitate, sodium laurate and the like. The amount added is 0, with respect to the polyolefin resin composition containing titanium dioxide.
It can be used in the range of 01 to 5% by weight, and is usually 0.02 to 2% by weight.

In the polyolefin resin composition of the present invention, in addition to titanium dioxide, white pigments such as zinc oxide, talc and calcium carbonate, fatty acid amides such as stearic acid amide and arachidic acid amide, cobalt blue, cobalt violet and navy blue. , Color pigments such as ultramarine, red iron oxide,
A fluorescent whitening agent or the like may be added.

The resin layer of the photographic support used in the present invention preferably further contains an antioxidant, particularly a hindered phenolic antioxidant.

Examples of the hindered phenolic antioxidant include
1.3.5-trimethyl-2.4.6-tris (3.5-di-tert-
Butyl-4-hydroxybenzyl) benzene, tetrakis [methylene (3.5-di-tert-butyl-4-hydroxy-hydrocinnamate)] methane, octadecyl-
3.5-di-tert-butyl-4-hydroxy-hydrocinnamate, 2.2'.2 "tris [3.5-di-tert-butyl-
4-hydroxyphenyl) propionyloxy] ethyl isocyanurate, 1.3.5-tris (4-tert-butyl-3-hydroxy-2.6-di-methylbenzyl) isocyanuric acid, tetrakis (2.4-di-tert-butylphenyl) 4.4 ′ -Biphenylenediphosphite, 4.4′-
Thiobis- (6-tert-butyl-O-cresol), 2.
2'-thiobis- (6-tert-butyl-4-methylphenol), tris- (2-methyl-4-hydroxy-5)
-Tert-butylphenyl) butane, 2.2'-methylene-
Bis- (4-methyl-6-tert-butylphenol),
4.4'-methylene-bis- (2.6-di-tert-butylphenol), 4.4'-butylidenebis- (3-methyl-6)
-Tert-butylphenol), 2.6-di-tert-butyl-4-methylphenol, 4-hydroxymethyl-2.
6-di-tert-butylphenol, 2.6-di-tert-butylphenol, 2.6-di-tert-butyl-4-n-butylphenol and the like can be mentioned. Further, two or more kinds of antioxidants may be used in combination depending on the characteristics of the antioxidant. The content of the antioxidant in the resin layer is 0.0005 to 1 part by weight, preferably 0.0005 to 0.1 part by weight, and more preferably 0.0005 to 100 parts by weight of the resin composition.
~ 0.025 parts by weight.

In particular, by including these hindered phenolic antioxidants in the resin layer of the photographic support, it is possible to obtain a photographic support excellent in light resistance even when the content of aluminum compound relative to titanium dioxide is low. .

The photographic support in the present invention is produced by melt-extrusion coating a polyolefin, preferably a polyethylene resin composition, in the form of a film from a slit die on a base paper that normally runs.

At this time, the melt extrusion temperature is preferably 200 ° C to 350 ° C. The slit die is preferably a T-type die, an L-type die or a fishtail type die, and the slit opening diameter is preferably 0.1 to 1 mm. In addition, before applying the resin composition to the base paper, it is preferable to subject the base paper to an activation treatment such as corona discharge treatment or flame treatment. The thickness of the resin layer of the resin-coated paper is not particularly limited, but it is generally advantageous that the resin layer is extrusion-coated to a thickness of about 5 to 50 microns. In ordinary polyethylene resin coated paper in which both sides of the base paper are coated with resin, the resin surface containing titanium dioxide (emulsion coated surface) may have a glossy surface, a matte surface, a silky surface, etc. depending on the application. However, the back surface is usually a matte surface, or if necessary, both front and back surfaces can be subjected to activation treatment such as corona discharge treatment and flame treatment.

The base paper used in the practice of the present invention is ordinary natural pulp,
Paper, synthetic fiber paper, so-called synthetic paper obtained by quasi-synthesizing synthetic resin film, or synthetic resin film may be used, but softwood pulp, hardwood pulp, natural pulp paper whose main component is wood pulp of hardwood mixed pulp It is used to advantage. The thickness of the base paper is not particularly limited, but a base paper having a smooth surface is preferable, and its basis weight is
50g / m ² ~250g / m ² is preferred.

The base paper containing natural pulp as a main component, which is advantageously used in the practice of the present invention, may contain various polymer compounds and additives. For example, cationized starch, cationized polyacrylamide, anionized polyacrylamide, carboxy-modified polyvinyl alcohol, gelatin, etc. as a dry paper strengthening agent, a fatty acid salt as a sizing agent,
As a pigment such as rosin derivative, dialkyl ketene dimer emulsion, petroleum resin emulsion, ammonium salt of styrene-maleic anhydride copolymer alkyl ester,
Clay, kaolin, calcium carbonate, barium sulfate, titanium oxide, etc. as a wet paper strength enhancer, melamine resin,
Urea resins, epoxidized polyamide resins, etc., such as aluminum sulfate, aluminum chloride, and other polyvalent metal salts as fixing agents, and cationic polymers such as chaotic starch, pH
As a regulator, caustic soda, sodium carbonate, hydrochloric acid, etc., and as an inorganic electrolyte, salt, mirabilite, etc., as well as dyes, optical brighteners, latexes, etc. may be appropriately combined and contained.

Various back coat layers can be coated on the photographic support in the invention for the purpose of preventing electrification and curling. In addition, the back coat layer, Japanese Patent Publication No.
No. 57-9059, 57-53940, 58-58
-56859, JP-A-59-214849, JP-A-58-184144 and the like or exemplified inorganic antistatic agents, organic antistatic agents, hydrophilic binders, latexes, curing agents, pigments, surfactants, etc. Can be contained in appropriate combination.

As the curing agent, either an inorganic curing agent or an organic curing agent can be used, but when a back coat layer containing styrene-butadiene acrylic latex and colloidal silica as main components is provided, an epoxy curing agent is used. For example, it is desirable to use Denacol EX830, EX841, EX931 (all Nagase & Co., Ltd.).

The photographic support in the present invention is coated with various photographic constituent layers for color photographic printing paper, reverse color photographic printing paper, black-and-white photographic printing paper, typesetting printing paper, copy printing paper,
It can be used for various applications such as reversal photographic materials, negative and positive silver salt diffusion transfer methods, and printing materials. For example, silver chloride, silver bromide, silver chlorobromide, silver iodobromide, and silver chloroiodobromide emulsion layers can be provided. The silver halide photographic emulsion layer can contain a color coupler to provide a multilayer silver halide constituent layer. Also, by including physical development nuclei,
A silver salt diffusion transfer image receiving layer can be provided. As the binder for the photographic constituent layers, in addition to ordinary gelatin, hydrophilic polymer substances such as polyvinylpyrrolidone, polyvinylalcool, and sulfated ester compounds of polysaccharides can be used. Further, the above-mentioned photographic constituent layers can contain various additives. For example, as sensitizing dyes, cyanine dyes, merocyanine dyes, etc., as chemical sensitizers, water-soluble gold compounds, sulfur compounds, etc., antifoggants or stabilizers, hydroxy-triazolopyrimidine compounds, mercapto-heterocyclic compounds, etc. , As hardener, formalin, vinyl sulfone compound, aziridine compound, etc., as coating aid, benzene sulfonate, sulfosuccinate salt, etc., as antifouling agent, dialkyl hydroquinone compound, etc., and other optical brightener, sharpness Improving dye, antistatic agent, pH adjusting agent,
A fogging agent and a water-soluble iridium or water-soluble rhodium compound may be appropriately combined and contained during the production and dispersion of the silver halide.

The silver halide photographic material according to the present invention is exposed, developed, and stopped according to the photographic material as described in "Photosensitive Material and Handling Method" (Kyoritsu Shuppan, Goro Miyamoto, Photographic Technology Course 2). Processing such as fixing, bleaching, stabilizing, etc., but especially for multi-layer silver halide color photographic materials which undergo one-bath bleach-fixing processing after color development are CD-III and CD-IV (the above two compounds are Kodak It is possible to process with a color developing solution of any main agent such as a trade name of the company) and droxychrome (trade name of May and Baker). A developing solution containing such a main agent may contain a development accelerator such as benzyl alcohol, thallium salt or phenidone. It is also possible to perform processing with a developer containing no benzyl alcohol. Further, a useful one-bath bleach-fixing solution is a solution of a metal salt of aminopolycarboxylic acid (for example, a ferric complex salt of ethylenediaminetetraacetic acid, propylenediaminetetraacetic acid, etc.), and a fixing agent such as sodium thiosulfate or thiosulfate. Ammonium sulfate and the like are useful. Various additives can be contained in the one-bath bleach-fixing solution. For example, desilvering accelerators (for example, mercaptocarboxylic acid described in U.S. Pat. No. 3,512,979, mercapto-heterocyclic compounds described in Belgian Patent No. 682426, etc.), antifouling agents, pH adjusters or PH buffers, dura mater. Various compounds such as agents (eg, magnesium sulfate, aluminum sulfate, potassium alum, etc.) and surfactants can be contained in combination. Also, although such a one-bath bleach-fix solution can be used at various pH's, the useful pH range is pH 6.0-8.0.

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

Examples 1 to 7 After hydrolysis according to the TiO ₂ production process by the sulfuric acid method described in the specification, washing, washing, and putting TiO ₂ concentrated in a kneader into a kneader, the addition amount is appropriately changed to change aluminum chloride. In addition, the mixture was thoroughly kneaded to obtain a TiO ₂ paste containing aluminum. These are placed in a rotary kiln heated to 980 ° C., and after firing, follow the steps described in the specification (excluding the surface treatment step and the washing / drying step).
An aluminum-containing anatase type titanium dioxide pigment as described in Note 1 was obtained.

Separately from this, according to the TiO ₂ production process by the sulfuric acid method described in the specification, except that the addition of aluminum chloride by the kneader is not performed, the same as the above, firing → pulverization / after sizing The TiO ₂ slurry was put in a surface treatment tank, sodium aluminate was added by appropriately changing the addition amount, well stirred, and the surface treatment was performed by a wet method. Thereafter, according to the steps described in the specification, Table 1 A comparative anatase type titanium dioxide pigment treated with aluminum oxide as described in Note 2 was obtained. In addition, a comparative anatase type titanium dioxide pigment which was not subjected to any surface treatment was also produced.

About 10 kinds of titanium dioxide pigments thus obtained, including the above-mentioned for comparison, low density polyethylene (density 0.92 g /
cm ³ , MI = 7) 70 parts by weight, titanium dioxide pigment 30 parts by weight and zinc stearate 1.5 parts by weight were well kneaded at 150 ° C. using a Banbury mixer to obtain 10 kinds of titanium dioxide pigments including those for comparison. Each masterbatch was obtained.

On the other hand, 50 parts by weight of bleached hardwood bleached kraft pulp and 50 parts by weight of softwood bleached sulfite pulp were beaten to 310 ml of Canadian Standard Freeness, and 3 parts by weight of cationized starch and anion were added to 100 parts by weight of pulp. 0.2 parts by weight of polyacrylamide, 0.4 parts by weight of alkyl ketene dimer emulsion (as ketene dimer content), 0.4 of polyaminopolyamide epichlorohydrin resin
By adding 1 part by weight, paper having a basis weight of 160 g / m ² was produced. The obtained wet paper is dried at 110 ° C., and then an impregnating solution containing 3 parts by weight of carboxy-modified polyvinyl alcohol, 0.05 part by weight of optical brightener, 0.002 part by weight of blue dye, 0.2 part by weight of citric acid and 97 parts by weight of water is added. It was impregnated with 25 g / m ² , dried with hot air at 110 ° C., further subjected to calendar treatment at a linear pressure of 90 Kg / cm, and then subjected to corona discharge treatment on both sides to produce a base paper for a photographic support.

Next, on the back side of the base paper, high density polyethylene (density 0.96 g /
cm ³ , MI = 7) and low density polyethylene (density 0.92g / cm ³ ,
A 1: 1 mixture of MI = 3) was coated at a resin temperature of 320 ° C. using a melt extrusion coater to a thickness of 30 μ. Next, 40 parts by weight of the titanium dioxide pigment masterbatch described above on the surface of the base paper, high-density polyethylene (density 0.96 g / cm ³ , MI = 7) 3
0 parts by weight and low density polyethylene (density 0.92 g / cm ³ , MI =
5) Add a resin composition containing 30 parts by weight to a resin temperature of 320
A photographic support containing a titanium dioxide pigment was prepared by coating at 30 ° C. to a thickness of 30 μm. At that time, the surface of polyethylene containing the titanium dioxide pigment was processed into a completely flat glossy surface, and the surface quality of the back polyethylene was processed into a matte surface such as paper.

The number of die lip stains shown in Table 1 and Note 3 was measured as follows.

The number of stains generated on the die lip is shown after melt-extruding for 2 hours at a melting temperature of 320 ° C. and a screw rotation of 100 rpm using a screw extruder having an extrusion diameter of 65 mm and a T-die having a width of 750 mm.

 The Y concentration shown in Table 1, Note 4 was measured as follows.

1 with Suga Test Instruments Fedometer (FAL-25X-HCL type)
Macbeth densitometer (TD-504 type) on the sample surface after 20 hours irradiation
It was measured at.

The larger the value of Y concentration, the greater the degree of yellowing and the more remarkable the light deterioration (the poor light resistance).

 Table 1 shows the obtained results.

Note 1 is Al ₂ O ₃ for the finished titanium dioxide pigment
Was calculated as the weight% of

TiO ₂ for comparison in Note 2 was also determined as% by weight of Al ₂ O ₃ relative to titanium dioxide pigment which is finished.

From Table 1, although 0.088% by weight of aluminum in Example 1 does not cause die lip stain, it has a high Y concentration and is defective, but Examples 2 to 7 (aluminum amount 0.11 to 2.32).
In the case of No. 3, there is no die lip stain, and the Y concentration is also low and good, especially in Examples 3 to 6 (aluminum content of 0.
18 to 1.21), the Y concentration is lower and a good photographic support can be obtained. Example 7 (aluminum content 2.32)
Was slightly inferior in whiteness.

On the other hand, it is understood that the aluminum having the aluminum content of 1.25 and 2.0% by weight, which has been subjected to the surface treatment by the wet method for comparison, has a low Y concentration and is good, but has stains on the die lip and is not suitable as a photographic support. . No surface treatment TiO
_In the case of ₂ (Comparative Example 1), there was no die lip stain, but it was found that the Y density was high and it was inappropriate.

Examples 8-10 Using the masterbatch used in Example 5, Table 2,
The same procedure as in Example 5 was carried out except that a photographic support was produced with the resin composition described in Note 1.

 Table 2 shows the obtained results.

From Table 2, the Ti content in the resin composition was measured using a masterbatch containing a titanium dioxide pigment having an aluminum content of 0.96 wt%.
It is understood that the photographic supports containing 15 to 21 parts by weight of O ₂ (Examples 8 to 10) can produce good photographic supports with no or very little die lip stain and low Y concentration. In addition, a photographic printing paper on which an image was formed through a series of photographic steps after coating a color emulsion on these photographic supports was remarkably excellent in sharpness.

Examples 11-13 Table 3 using the masterbatch used in Example 4,
The same procedure as in Example 4 was carried out except that a photographic support was produced with the resin composition described in Note 1.

 The results obtained are shown in Table 3.

From Table 3, the Ti in the resin composition was prepared using a masterbatch containing a titanium dioxide pigment having an aluminum content of 0.55% by weight.
It can be seen that the photographic supports containing 21 to 24 parts by weight of O ₂ (Examples 11 to 12) can produce good photographic supports with no or very little die lip stain and low Y concentration. Further, the photographic printing paper on which an image was formed through a series of photographic steps after coating a color emulsion on these photographic supports was obtained with extremely excellent sharpness. On the other hand, the photographic support containing 27 parts by weight of TiO ₂ in the resin composition (Example 13) had a low Y concentration and an extremely good sharpness, but a slight occurrence of die lip stain was observed.

Examples 14 to 16 According to the TiO ₂ production process by the chlorine method described in the specification,
Using a device similar to USP312641, after simultaneously supplying titanium tetrachloride, oxygen and aluminum chloride into the combustion reaction tower at 1500 ° C. during the oxidation step, according to the steps described in the specification (however, the surface treatment step And excluding the washing and drying process) 0.75% by weight aluminum (Al ₂ O _{3 based} on the finished TiO ₂
To obtain a rutile-type titanium dioxide pigment.

50 parts by weight of low-density polyethylene (density 0.92 g / cm ³ , MI = 5) of the titanium dioxide pigment thus obtained,
50 parts by weight of titanium dioxide pigment and 2.5 parts by weight of magnesium stearate were well kneaded at 150 ° C. using a Banbury mixer to obtain a titanium dioxide pigment-containing masterbatch.

The same procedure as in Example 1 was carried out except that a photographic support was produced with the resin composition shown in Table 4, Note 1.

 The results obtained are shown in Table 4.

From Table 4, using a masterbatch containing 0.75% by weight of aluminum rutile TiO ₂ , the TiO ₂ content in the resin composition was 20 to 20%.
The photographic support containing 25 parts by weight (Examples 14 to 15) had no or very little die lip stain, and Y
It can be seen that a good photographic support having a low density can be obtained.
Further, a photographic printing paper on which an image was formed through a series of photographic steps after coating a color emulsion on these photographic supports had excellent sharpness. On the other hand, the photographic support containing 30 parts by weight of TiO ₂ in the resin composition (Example 16) had a low Y concentration and extremely good sharpness, but some die lip stain was observed.

Example 17 After hydrolysis according to the titanium dioxide production process by the sulfuric acid method described in the specification, washed, washed, put the titanium dioxide concentrated in a filter into a kneader, Al ₂ O to titanium dioxide
Aluminum chloride was added so as to be 0.52% by weight as ₃ and kneaded well to obtain a titanium dioxide paste containing aluminum. These were placed in a rotary kiln heated to 980 ° C, fired, and then crushed with a Raymond mill (Sample 1). Trimethylolpropane was added to titanium dioxide 100 before firing the clinker into the Raymond mill.
0.01 parts by weight of trimethylol propane was added to 0.01 parts by weight per 100 parts by weight of titanium dioxide (sample 2), sample 1 was further steam-milled (sample 3), and sample 3 was steam-milled. What was added in an amount of 1 part by weight (Sample 4), triethanolamine was added to titanium dioxide 100 before entering the Raymond mill in Sample 4.
A sample (Sample 5) added so that 0.05 parts by weight per part by weight was prepared.

Separately from this, according to the titanium dioxide production process by the sulfuric acid method described in the specification, the same procedure as above is performed except that the addition of aluminum chloride by the kneader is not performed, and the titanium dioxide slurry after firing → pulverization is prepared. Put it in a surface treatment tank, add sodium aluminate so that Al ₂ O ₃ will be 0.52% by weight with respect to titanium dioxide, stir well, and perform the surface treatment by the wet method. A comparative anatase-type titanium dioxide pigment, which had been treated with aluminum oxide according to the steps of Example 1 and Table 5 of the Example, was obtained. These five types of comparative samples are sample 1 in the present invention.
.About.5, Comparative Samples 1 to 5, respectively.

About 10 kinds of titanium dioxide pigments thus obtained, including the above-mentioned for comparison, low density polyethylene (density 0.92 g /
cm ³ , MI = 5) 70 parts by weight, 30 parts by weight of the titanium dioxide pigment and 15 parts by weight of zinc stearate were well kneaded at 150 ° C. using a Banbury mixer, and contained 10 kinds of titanium dioxide pigments including those for comparison. Of the respective master batches were obtained.

On the other hand, a base paper for a photographic support was manufactured in exactly the same manner as in Example 1.

Next, on the back side of the base paper, high density polyethylene (density 0.96 g /
cm ³ , MI = 7) and low density polyethylene (density 0.92g / cm ³ ,
A 1: 1 mixture of MI = 3) was coated at a resin temperature of 320 ° C. using a melt extrusion coater to a thickness of 30 μ. Then, on the surface of the base paper, a master batch 30 of the above-mentioned titanium dioxide pigment was prepared.
Parts by weight and low-density polyethylene (density 0.92 g / cm ³ , MI =
5) Add a resin composition containing 70 parts by weight to a resin temperature of 320
A photographic support containing a titanium dioxide pigment was prepared by coating at 30 ° C. to a thickness of 30 μm. At that time, the surface of polyethylene containing the titanium dioxide pigment was processed into a completely flat glossy surface, and the surface quality of the back polyethylene was processed into a matte surface such as paper.

The number of microgrits shown in Table 5 was measured as follows.

The number of microgrit generated on the resin surface containing the titanium dioxide pigment and the like of the photographic support produced by the method described in the examples was visually counted.

 The results obtained are shown in Table 5.

From Table 5, when a photographic support was produced using the aluminized titanium dioxide according to the present invention, when a steam mill was used as a crusher in addition to the Raymond mill, generation of microgrit was small (Sample 3 ), And the addition of trimethyl roll propane at the time of pulverizing with a steam mill generated less microgrit (Sample 4),
Further, it can be seen that the addition of triethanolamine before crushing with the Raymond mill, and the addition of trimethylol pullpan during crushing with the steam mill generate far less microgrit. However, only the Raymond mill crushing (Sample 1) or the one to which trimethylol pull pan was added before the Raymond mill crushing (Sample 2) generated a large amount of microgrit and was not suitable as a photographic support.

On the other hand, when a photographic support was produced using externally coated titanium dioxide by wet surface treatment for comparison, even if a steam mill was used in addition to the Raymond mill, photographic support with a large amount of microgrit was used. Even if only the body was obtained (Comparative sample 3), and the ones using the same grinding aid as the corresponding sample number when used in combination with the above-mentioned crusher (Comparative samples 4 and 5), still with a lot of generation of microgrit It turns out that only a support can be obtained.

Example 18 After hydrolysis according to the titanium dioxide production process by the sulfuric acid method described in the specification, washed, put titanium dioxide concentrated in a kneader in a filter, add aluminum chloride by appropriately changing the addition amount, The mixture was thoroughly kneaded to obtain a titanium dioxide paste containing aluminum. These were placed in a rotary kiln heated to 980 ° C., fired, crushed by Raymond mill, and further crushed by steam mill to obtain anatase-type titanium dioxide containing aluminum as shown in Table 6.

Separately from this, according to the titanium dioxide production process by the sulfuric acid method described in the specification, the same procedure as above is performed except that the addition of aluminum chloride by the kneader is not performed, and the titanium dioxide slurry after firing → pulverization is prepared. Put it in a tank for surface treatment, add sodium aluminate with an appropriate addition amount, stir well, perform surface treatment by a wet method, wash and dry, grind with raymond mill, and further grind with steam mill Comparative anatase type titanium dioxide pigments treated with aluminum oxide as shown in Table 2 were obtained.
Also, a comparative anatase type titanium dioxide pigment, which was not subjected to any surface treatment, was produced in the same manner.

With respect to the ten kinds of titanium dioxide pigments thus obtained, including the above-mentioned comparative ones, a photographic support was obtained in the same manner as in Example 1, and the microgrit and the Y concentration were measured.

 The obtained results are shown in Table 6.

From Table 6, although 0.081% by weight of aluminum in Sample 6 produces considerably less microgrit, it has a high Y concentration and is unsatisfactory, but Samples 7 to 12 (aluminum content 0.10 to 2.2
In the case of 2), the generation of microgrit is small, and Y
It is understood that the density is low and good, and particularly in Samples 8 to 11 (aluminum content 0.17 to 1.24), the Y density is lower and a good photographic support can be obtained.

Sample 12 (aluminum content 2.22) was slightly inferior in whiteness.

On the other hand, the comparative wet-process surface treated aluminum contents of 1.25 and 2.0% by weight (Comparative Examples 2 and 3)
It is understood that the Y concentration is low and good, but the generation of microgrit is large and it is unsuitable as a photographic support. or,
It can be seen that in the case of the titanium dioxide pigment without surface treatment (Comparative Example 1), microgrit is generated and the Y concentration is high, which is inappropriate.

Example 19 When a masterbatch was prepared using the titanium dioxide pigment of Sample 7 in Example 18, tetrakis [methylene (3,5-di-tert-butyl-4-hydroxy-hydrocinnato)] was added to the masterbatch. Methane added with 150 ppm (Example 19-1) and 1,3,5-tris (4-tert)
-Butyl-3-hydroxy-2,6-dimethylbenzyl)
What added 100 ppm of isocyanuric acid (Example 19-2)
Were prepared individually, and thereafter sample 7 in Example 18 was prepared.
A photographic support was obtained in the same manner as in (1), and the microgrit and Y
The concentration was measured.

As a result, in both Examples 19-1 and 19-2, the microgrit was almost the same as that of Sample 7, but the Y concentration was in Example 19-.
It was 0.04 for both 1 and 19-2, and a photographic support superior in whiteness to Sample 7 was obtained.

Example 20 Example 18 was carried out in the same manner as in Example 18 except that the master batch of Sample 9 in Example 18 was used to produce a photographic support with the resin composition shown in Table 7. The results obtained are shown in Table 7.

From Table 7, 15-21 parts by weight of titanium dioxide pigment in the resin composition was blended using a masterbatch containing a titanium dioxide pigment having an aluminum content of 0.52% by weight (Samples 13-15).
It can be seen that the photographic support produces a good photographic support with less generation of microgrit and a low Y concentration.

Also, after coating a color emulsion on these photographic supports,
The photographic printing paper on which an image was formed through a series of photographic steps was excellent in sharpness.

Example 21 According to the titanium dioxide production process by the chlorine method described in the specification, using an apparatus similar to USP3121641, during the oxidation process, titanium tetrachloride, oxygen and aluminum chloride were simultaneously introduced into a combustion reaction tower at 1500 ° C. After the supply, the rutile titanium dioxide pigment containing 0.8% by weight of aluminum (Al ₂ O ₃ % by weight relative to the finished titanium dioxide) was pulverized with a hammer mill equipped with a quantitative feeder through a separation process and then pulverized with a steam mill. Obtained.

50 parts by weight of low-density polyethylene (density 0.92 g / cm ³ , MI = 7), 50 parts by weight of the titanium dioxide pigment and 2.5 parts by weight of magnesium stearate were placed in a Banbury mixer for the titanium dioxide pigment thus obtained. Put, 150
The mixture was well kneaded at 0 ° C to obtain a titanium dioxide pigment-containing masterbatch.

Then, the procedure of Example 17 was repeated except that a photographic support was produced with the resin composition shown in Table 8. The results obtained are shown in Table 8.

From Table 8, 20 to 25 parts by weight of the titanium dioxide pigment in the resin composition was blended using a master batch containing a rutile type titanium dioxide pigment of 0.8% by weight of aluminum (Sample 16 to
17) The photographic support produces less microgrit,
It is also understood that a good photographic support having a low Y concentration can be obtained. Further, a photographic printing paper on which an image was formed through a series of photographic steps after coating a color emulsion on these photographic supports had excellent sharpness. On the other hand, the photographic support containing 30 parts by weight of the titanium dioxide pigment in the resin composition (Sample 18) had a low Y concentration and an extremely good sharpness.
Occurrence of microgrit was slightly increased.

Example 22 The resin compositions shown in Table 9 were prepared in the same manner as in Example 1 using a Banbury mixer, and then extruded into pellets using an extruder for kneading to produce compounds.

After that, the number of die lip stains, the Y concentration, and the number of microgrit were determined according to the measuring methods described in Examples 1 and 17.

 The results obtained are shown in Table 9.

From Table 9, Samples 20 to 24 containing 0.0005 to 1.0 part by weight of the antioxidant in the resin composition were excellent in die lip stain, Y concentration and microgrit, and were more excellent in sharpness.

Further, it is understood that Samples 20 to 23 containing 0.0005 to 0.1 parts by weight do not cause die lips and a still better photographic support can be obtained. On the other hand, the sample 19 containing no antioxidant in the resin composition has a high Y concentration, and the sample 25 containing 1.5 parts by weight of the antioxidant has a slightly large amount of both die lip stains and microgrit, both of which are for photography. It turns out that it is not suitable as a support.

Claims (8)

[Claims] 1. A method for producing a photographic support in which at least one surface of a base paper is coated with a resin composition comprising at least a polyolefin and a titanium dioxide pigment, and the resin composition is a polyolefin and a sulfuric acid method before the firing step. In the chlorine method, an aluminum compound was added so that the amount of aluminum with respect to titanium dioxide was 0.1 to 2.0% by weight in the form of Al ₂ O ₃ during the oxidation step, and then the sulfuric acid method was performed through a firing step. A process for producing a photographic support, which comprises a titanium dioxide pigment. 2. A method for producing a photographic support according to claim 1, wherein the titanium dioxide pigment is ground by a fluid energy mill. 3. The method for producing a photographic support according to claim 2, wherein the fluid energy mill is a steam mill. 4. The method for producing a photographic support according to claim 1, wherein the titanium dioxide contains a grinding aid before it is ground in a fluid energy mill. 5. The method for producing a photographic support according to claim 1, wherein the aluminum compound is aluminum chloride. 6. The method for producing a photographic support according to claim 1, wherein an antioxidant is contained in the resin composition. 7. The method for producing a photographic support according to claim 6, wherein the antioxidant is a hindered phenolic antioxidant. 8. The method for producing a photographic support according to claim 1, wherein the titanium dioxide pigment contained in the resin composition is 9 to 25% by weight.