JPH0363059B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention provides a photographic resin composition, more specifically, the occurrence of die lip stain using the photographic resin composition is significantly reduced, and micro grit (micro grit) is produced.
The present invention relates to a photographic resin-coated paper that has extremely little grit (grit) and is good against fogging. The essential structure of photographic resin-coated paper containing a photographic resin composition in the resin layer is already known, and for example, as disclosed in U.S. Pat. No. 3,501,298, both sides of the paper base are coated with resin. In this method, the resin layer on the emulsion-coated side contains a titanium dioxide pigment, a blue pigment, a fluorescent whitening agent, etc. However, resin compositions containing titanium dioxide pigments,
In particular, when melt-extruding a polyethylene resin composition into a film from a slit die, there is a tendency for needle-shaped or icicle-shaped deposits or stains (hereinafter simply referred to as die lip stains) to occur on the tip of the die lip during short extrusion. Unfortunately, this die lip stain tends to grow larger and larger as the melt extrusion time elapses. If this die lip stain occurs during melt extrusion coating, vertical streaks may appear on the surface of the photographic resin-coated paper manufactured 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 the resin-coated paper produced is significantly impaired, making it completely unsuitable as a photographic support that requires an excellent surface area, and having no commercial value. Additionally, the only way to completely remove die lip stains once they have occurred is to stop production and clean the die lip, which requires a great deal of effort and time, resulting in a significant drop in productivity. As a result, an urgent solution was required. On the other hand, the term "microgrit" as used herein refers to minute foreign matter or minute grains that appear on the surface of the coated resin in photographic resin-coated paper where at least one side of paper or synthetic paper is coated with a resin composition. Point. There are various causes of microgrit, but for example, the microgrit that appears on photographic resin-coated paper manufactured by melt-extruding photographic resin onto at least one side of a paper or synthetic paper substrate using a melt extruder is the cause of microgrit. (1) Regarding the resin itself used,
If a lot of gel is generated, (2) when the molten resin is extruded into a film from the melt extruder through the die,
(3) If 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) Insufficient bending in the melt extruder, etc., but these can often be resolved relatively easily by skilled engineers. However, the most difficult countermeasure against microgrit is when microgrit occurs in photographic resin-coated paper in which a paper or synthetic paper substrate is coated with a resin composition mainly consisting of resin and pigment. In the first place, the method for incorporating pigments into low-density polyethylene is to create a so-called master batch in which pigments are contained in resin at a high concentration in advance, and then dilute and mix them with diluted resin to the desired ratio. It is usual to prepare and use a so-called compound in which a desired composition ratio of pigment is contained in a resin from the beginning. However, when preparing a masterbatch or compound by melt-kneading resin and pigment using an ordinary melt-kneading machine such as a Banbury mixer or kneader, relatively coarse pigment particles in the resin may be in a fine state. There is a tendency for pigment particles to be dispersed as they are without being dispersed, and thus undispersed pigment particles will be present in the masterbatch or compound. As a result, at least one side of the paper or synthetic paper substrate is coated with a resin composition mainly composed of pigment and resin produced using the masterbatch or the compound. Micro grit will be generated. The occurrence of microgrit in resin-coated papers used as photographic supports causes serious photographic defects. That is, when a person is photographed on a photographic paper having a resin-coated paper containing microgrit as a photographic support, if microgrit appears in areas such as the face, the photograph has no commercial value.
Fog is a phenomenon in which when a photographic light-sensitive material is developed, a slight photographic density appears even in areas that have not been exposed to light, and the occurrence of fog is a fatal defect for photographic resin-coated paper. By the way, when a so-called master batch is produced by kneading resin and pigment using a kneading machine such as a Banbury mixer, it is often insufficient to simply knead the two; When melt-extrusion coating is applied onto a support such as paper, the aforementioned microgrit is produced frequently, and the resultant support is often extremely unsuitable for use as a photographic support. To improve this point, a lubricant such as a fatty acid metal salt is often added during kneading. However, when a resin composition containing a so-called masterbatch or compound containing these lubricants is melt-extruded using a melt extruder, the die lip stain described above is likely to occur, resulting in a significant decrease in workability and the use of a photographic support. It was found that this resulted in quality deterioration. Moreover, this tendency
The problem is more noticeable when ultramarine blue is included than when titanium dioxide pigment is used alone, and an immediate solution has been desired. This is because in the photographic industry, it is essential to apply ultramarine blue to the resin layer of a photographic support (to create a white appearance), which is called bluing. . Additionally, when a resin composition containing low-density polyethylene and titanium dioxide pigment as the main ingredient further contains ultramarine blue and an antioxidant, fogging usually occurs compared to a resin composition that does not contain ultramarine blue and an antioxidant. It tends to be easy. However, as mentioned above, the use of ultramarine is essential to impart a blue tint, and antioxidants are often used to prevent resin deterioration, but depending on the type of antioxidant, it may cause fogging. The reality is that there are many antioxidants, and it takes a lot of effort and time to select antioxidants that cause less fog. In order to solve this contradiction, the present inventors conducted various studies and found that in a resin composition mainly composed of low density polyethylene and titanium dioxide pigment, 0.05 to 10% of ultramarine was added to 100 parts by weight of the resin composition.
Weight part, antioxidant 5-150ppm, zinc stearate or/and magnesium stearate 0.1
By applying a photographic resin composition containing ~5 parts by weight to the resin layer of a photographic support, generation of die lip stains and microgrit can be effectively prevented, and furthermore, in the present invention, an antioxidant is used. The present inventors have discovered that even with this method, no fogging occurs and better results can be obtained than when no antioxidant is used, leading to the present invention. As the fatty acid metal salt used in the present invention, zinc stearate, magnesium stearate, or a combination thereof exhibits good efficacy. It was found to have a negative effect on dirt and microgrit. That is, the excellent effect of the photographic resin composition of the present invention is that in the resin composition mainly containing low density polyethylene and titanium dioxide pigment, a specific amount of ultramarine blue, a specific amount of antioxidant, and This is achieved by combining it with a specific lubricant, and the reason for this is currently unknown.
In any case, it is thought that this is due to a synergistic effect between them. As the antioxidant used in the present invention, any commercially available antioxidant can be used as long as it does not cause any problems when applied to photographic resin compositions, but especially hinderers can be used. Dophenolic antioxidants are preferred. For example 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) isocyanurate, tetrakis (2,4-di-tert-butylphenyl) 4,4'-biphenylene diphosphite,
4.4'-thiobis-(6-tert-butyl-0-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-hydroxy methyl-2.6-
Examples include di-tert-butylphenol and 2.6-di-tert-butyl-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 5 to 150 ppm, preferably 5 to 100 ppm, more preferably 5 to 100 ppm, per 100 parts by weight of the resin composition.
It is 50ppm. If the amount of antioxidant is less than 5 ppm or more than 150 ppm, die lip stains and microgrits will be generated in large quantities, and fogging will also occur more easily, which is not preferable. In the present invention, as a method for containing 5 to 150 ppm of antioxidant in the resin composition, a so-called compound in which the antioxidant is pre-contained in the low density polyethylene used may be used, or a relatively An appropriate amount of resin containing a high concentration of antioxidant may be used, or the antioxidant may be added when producing the resin composition using a kneader. Furthermore, depending on the type of antioxidant used, the above methods may be combined as appropriate. As the ultramarine blue used in the present invention, any commonly commercially available ultramarine blue can be used as long as it does not cause any problems when applied to photographic resin compositions. For example, Aokuchi Gunjo No.8000, No.4000, No.3000, No.2000, Akakuchi Gunjo No.1900, No.1500, No.300, processed Gunjo No.3000A manufactured by Daiichi Kasei Kogyo Co., Ltd.,
No.1500A, PB-80, DV-1, DV-2, etc., and in some cases, CB-80, CR-50, DR-
1. Cosmetic ultramarine blues such as DP-3 can also be used. In addition, various types of ultramarine may be used in appropriate combination to produce a desired color. In the present invention, the amount of ultramarine contained in 100 parts by weight of the resin composition is preferably 0.05 to 10 parts by weight.
If it exceeds 10 parts by weight, die lip stains and microgrit will be generated significantly, and if it is less than 0.05 parts by weight, the blue tint effect will not be exhibited well. The content of titanium dioxide pigment in the resin composition in the present invention is usually 100 parts by weight of the resin composition.
15 to 60 parts by weight, although 20 to 50 parts by weight are advantageously used in the practice of this invention. The titanium dioxide pigments used in the practice of the present invention include those produced by the sulfuric acid method, those produced by the chlorine method,
Further, although either rutile type or anatase type may be used, the anatase type is advantageous in terms of whiteness.
In addition, titanium dioxide pigments without surface treatment can be used, titanium dioxide pigments coated with an inorganic surface treatment agent such as hydrous aluminum oxide, or organic surface treatment agents such as organopolysiloxane can be used. It is also possible to use a surface treated with an inorganic surface treatment agent and an organic surface treatment agent in an appropriate combination. The low-density polyethylene resin used in the practice of the present invention may be one produced by a tank reactor or a tubular reactor, or a low-density polyethylene resin produced by both methods. Polyethylene resins may be used in appropriate combinations. Further, materials having various densities and melt viscosity indexes (hereinafter simply referred to as MI) can be used alone or in combination. Further, when preparing the resin composition, other polyolefin resins such as high-density polyethylene, polypropylene, etc. may be mixed as appropriate to the extent that they do not interfere with the use as a photographic resin composition. The content of the titanium dioxide pigment used in the photographic resin composition of the present invention in the resin layer of the photographic resin-coated paper is 5% by weight or less based on the resin, so that it has no hiding power as a photographic support. On the other hand, if it exceeds 40% by weight, the fluidity etc. decreases, which is not preferable, and particularly preferably 7.5% by weight to 25% by weight.
% by weight. In the photographic resin composition of the present invention, white pigments such as zinc oxide, talc, and calcium carbonate, coloring pigments such as cobalt blue, cobalt violet, and deep blue, and fluorescent whitening agents may be added to the photographic resin composition of the present invention. May be added. The photographic resin-coated paper containing the photographic resin composition in at least one resin layer according to the present invention is a photographic resin-coated paper containing a photographic resin composition in at least one resin layer. Manufactured by melt extrusion coating into a film using a slit die. Usually, the melt extrusion temperature is preferably 200°C to 350°C. Furthermore, before coating the resin composition on the base paper, it is preferable to subject the base paper to an activation treatment such as a corona discharge treatment or a fire treatment. There is no particular limit to the thickness of the resin layer of the resin-coated paper, but it is generally advantageous to extrude coat it to a thickness of about 5 microns to 50 microns. In addition, in ordinary resin-coated paper in which both sides of the base paper are coated with resin, the resin surface containing titanium dioxide pigment has a glossy surface, a matte surface, a silky surface, etc. depending on the use. The opposite back side is usually matte, and if necessary, corona discharge treatment is applied to both the front and back sides.
It can be used for activating treatments such as water disaster treatment. The base paper used in the practice of the present invention may be ordinary natural pulp paper, synthetic fiber, or so-called synthetic paper made from synthetic resin film.
Natural pulp paper based on wood pulp of softwood pulp, hardwood pulp, softwood hardwood mixed pulp is advantageously used. The base paper is preferably one with good surface smoothness. Further, there is no particular restriction on the thickness of the base paper, but it is preferably 50 to 250 g/m ² in terms of basis weight. The base paper mainly composed of natural pulp, which is advantageously used in the practice of the present invention, can contain various polymer compound additives. For example, dry paper strength enhancers include cationized starch, cationized polyacrylamide, anionized polyacrylamide, carboxy-modified polyvinyl alcohol, gelatin, etc. Sizing agents include fatty acid salts, rosin derivatives, dialkyl ketene dimer emulsions, petroleum resin emulsions, etc. , ammonium salt of styrene-maleic anhydride copolymer alkyl ester, clay, kaolin, calcium carbonate,
Wet paper strength enhancers such as barium sulfate and titanium oxide; melamine resins, urea resins, and epoxidized polyamide resins; fixing agents such as polyvalent metal salts such as aluminum sulfate and aluminum chloride; and cationically modified polymers such as cationized starch. , pH regulators such as caustic soda, soda carbonate, and hydrochloric acid; inorganic electrolytes such as common salt and mirabilite; in addition, dyes, fluorescent whitening agents, latex, and the like may be contained in appropriate combinations. The photographic resin-coated paper to which the photographic resin composition of the present invention is applied can be provided with various silver halide photographic emulsion layers. For example, silver chloride, silver bromide, silver chlorobromide, silver iodobromide, and silver chloroiodobromide emulsion layers can be provided. Furthermore, a multilayer silver halide photographic constituent layer can be provided by incorporating a color coupler in the silver halide photographic emulsion layer. As the binder for these silver halide emulsion layers, in addition to ordinary gelatin, hydrophilic polymeric substances such as polyvinylpyrrolidone, polyvinyl alcohol, and polysaccharide sulfate ester compounds can be used.
Further, the above-mentioned silver halide emulsion layer can contain various additives. For example, sensitizing dyes include cyanine dyes and merocyanine dyes; chemical sensitizers include water-soluble gold compounds and sulfur compounds; antifoggants and stabilizers include hydroxy-triazolopyrimidine compounds;
As a hardening agent, such as mercapto-heterocyclic compounds,
Formalin, vinyl sulfonate compounds, aziridine compounds, etc., as coating aids, benzenesulfonate, sulfosuccinate salts, etc., stain preventive agents, dialkylhydroquinone compounds, etc., as development accelerators, hydroquinone, phenidone, etc., ultraviolet absorbers. As agents, in addition to benzotriazole compounds, fluorescent whitening agents, sharpness-improving dyes, antistatic agents, PH regulators, and water-soluble iridium compounds and water-soluble rhodium compounds are used in the production and dispersion of silver halide, as appropriate. It can be made to contain. Further, on the back side of the photographic resin-coated paper in the present invention, that is, on the support surface opposite to the side on which the photographic constituent layer, in most cases the silver halide photographic constituent layer, is coated, anti-curl, antistatic, etc. A coating layer consisting of a hydrophilic colloid layer called a back coat layer can be provided for the purpose of preventing adhesion and slipping. Such a back coat layer may contain a binder, a protective colloid, a curing agent, an antistatic agent, a surfactant, a matting agent, a latex, and the like. Next, in order to explain the present invention more specifically,
An example will be described. Example 1 Low density polyethylene (density 0.918 g/cm ² ,
Tetrakis [[methylene (3.5-di-tert-butyl-4-hydroxy- Hydrocinnamate)] Contains methane to make A/O blended resin (However,
Sample No. 1 does not contain). 67.5 parts by weight of each of these resins were collected in a Banbury mixer, and Table 1,
The amount of titanium dioxide pigment, the amount of ultramarine, and the amount of zinc stearate and/or magnesium stearate described in Note 1 were added, respectively, and the mixture was thoroughly kneaded at 150° C. to obtain a masterbatch containing pigment, etc., respectively. On the other hand, a mixed stock of 50 parts by weight of bleached hardwood kraft pulp and 50 parts by weight of bleached softwood sulfite pulp was prepared using Canadian Standard Freeness 310.
ml, and further added to 100 parts by weight of pulp, 3 parts by weight of cationized starch, 0.2 parts by weight of anionized polyacrylamide, 0.4 parts by weight of alkyl ketene dimer emulsion (as ketene dimer content), and 0.4 parts by weight of polyaminopolyamide epichlorohydrin resin. A paper with a basis weight of 160 g/m ² was made.
The obtained wet paper paper was dried at 110°C and then impregnated with an impregnating solution consisting of 3 parts by weight of carboxy-modified polyvinyl alcohol, 0.05 parts by weight of a fluorescent brightener, 0.002 parts by weight of blue dye, 0.2 parts by weight of citric acid and 97 parts by weight of water. 25
After drying with hot ^air at 110° C. and supercalendering at a linear pressure of 90 kg/cm, both surfaces were subjected to corona discharge treatment to produce a base paper for photographic resin-coated paper. Next, apply high-density polyethylene (density
A 1:1 mixture of 0.96 g/cm ² , MI=5) and low-density polyethylene (density 0.92 g/cm ² , MI=5) was melt-extruded to a thickness of 30μ using a melt extrusion coating machine at a resin temperature of 330°C. Coated. Next, 30 parts by weight of a masterbatch containing the titanium dioxide pigment described above and high-density polyethylene (density 0.96 g/
cm ³ , MI=5) and 40 parts by weight of low-density polyethylene (density 0.92 g/cm ² , MI=5) was coated to a thickness of 30μ at a resin temperature of 320°C. , the antioxidant content is different, and
Polyethylene resin-coated papers containing titanium dioxide pigments and the like were produced respectively. At that time, the surface of the polyethylene containing titanium dioxide pigment etc. was processed into a completely flat glossy surface, and the surface quality of the back polyethylene was processed into a paper-like matte surface. Table 1 shows the number of die lip stains when resin compositions having different antioxidant contents and containing titanium dioxide pigment, etc. were used. The number of die lip stains and the number of microgrits were determined by the following method. <Number of dye lip stains> Master batches of the 10 types shown in Table 1 with different antioxidant contents and containing titanium dioxide pigments, etc. were determined under the following conditions using the resin formulations described in the examples. Using a screw extruder with an extrusion port diameter of 65 mm and a melt extruder with a T-die of 750 mm width, the melt temperature
The number of stains generated on the die lip after melt extrusion at 320°C and screw rotation of 100 rpm for 2 hours is shown. <Number of Microgrits> The number of microgrits generated on the polyethylene resin surface containing titanium dioxide pigment etc. of photographic polyethylene coated paper produced by the method described in the Examples was visually counted.

[Table] From Table 1, when 100 parts by weight of the resin composition contains 30 parts by weight of TiO ₂ and 1 part by weight of ultramarine, and 1.5 parts by weight of zinc stearate,
Both the sample containing no antioxidant (Sample No. 1) and the sample containing 500 to 1000 ppm of antioxidant (Samples No. 7 and No. 8) caused significant die lip staining, making it difficult to use as a photographic support. It turns out that this is inappropriate. On the other hand, add 5 to 150 ppm of antioxidants.
It can be seen that those containing the above-mentioned materials (Samples No. 2 to No. 6) are well able to prevent the occurrence of die lip stains.
Furthermore, it can be seen that those containing 5 to 100 ppm are better prevented, and those containing 5 to 50 ppm are even more prevented. Separately, it contains magnesium stearate instead of zinc stearate, and has a lower antioxidant content.
50ppm (Sample No. 9) and a combination of zinc stearate and magnesium stearate with an antioxidant content of 50ppm (Sample No. 10) both showed no die lip stains. It can be seen that this is extremely well prevented.
Further, in the photographic supports in which the photographic resin compositions according to the present invention were applied in the resin layer, the generation of microgrit was well prevented, and supports suitable for photographic purposes were obtained. Example 2 The same low-density polyethylene resin containing 50 ppm of antioxidant as in Example 1 was used, except that a master batch containing the titanium dioxide pigment, ultramarine, and each zinc stearate amount described in Note 2 was used. , in the same manner as in Example 1. The results obtained are shown in Table 2.

[Table] From Table 2, 100 parts by weight of the resin composition contained 30 parts by weight of TiO ₂ and 1 part by weight of ultramarine, did not contain zinc stearate, and contained 50 ppm of antioxidant.
It can be seen that the sample in which this was added (Sample No. 11) caused less die lip staining, but produced significantly more microgrit, making it unsuitable as a photographic support. In addition, those containing 10 parts by weight of zinc stearate and 50 ppm of antioxidant,
It can be seen that die lip stains and microgrit were generated frequently, making it unsuitable as a photographic support. On the other hand, zinc stearate according to the present invention is 0.1~
The samples containing 5 parts by weight and 50 ppm of antioxidant (Samples No. 12 to No. 14) were all highly effective in preventing the generation of die lip stains and microgrit, making them suitable as photographic supports. I got something. Example 3 Low density polyethylene (density 0.926 g/cm ³ ,
25 ppm of 1.3.5-trimethyl-2.4.6-tris(3.5-di-tert-butyl-4-hydroxybenzyl)benzene was added to MI=6) to prepare an A/O blended resin. The above A/O compound resin, titanium dioxide pigment, ultramarine blue and zinc stearate were placed in a Banbury mixer and kneaded well at 150°C so that the contents were as shown in Note 3 of Table 3. Obtained a master batch. The procedure was the same as in Example 1, except that the resin composition used in melt extrusion using the extruder described in the Example was as shown in Table 3, Note 4. The results obtained are shown in Table 3.

[Table] From Table 3, 20 parts by weight of TiO ₂ , 1 part by weight of zinc stearate, and antioxidant in 100 parts by weight of the resin composition.
In the case of resin compositions containing 25 ppm and 0.05 to 10 parts by weight of ultramarine (Samples No. 16 to No. 19), the generation of die lip stains and microgrit was extremely well prevented, and the photographic support A suitable product was obtained. On the other hand, when ultramarine blue was contained in an amount of 15 parts by weight (Sample No. 20), die lip stains and microgrit were generated in a significantly large amount, making the support unsuitable for use as a photographic support. Example 4 Low density polyethylene (density 0.918 g/m ² ,
MI=8), 1.3.5-tris(4-tert-butyl-3-hydroxy-2.6-di-methylbenzyl)
A/O compound resin is made by containing 25 ppm of isocyanurate. The above A/O blended resin, titanium dioxide pigment, ultramarine blue, and zinc stearate, calcium stearate, or stearic acid were respectively placed in a Banbury mixer so that the contents were as shown in Table 4, note 5, The mixture was thoroughly kneaded at 150°C to obtain a masterbatch containing pigments, etc. 23.3 parts of masterbatch containing the above titanium dioxide pigment, etc. and low density polyethylene (density 0.926
Example 1 was carried out in the same manner as in Example 1, except that a resin composition having a formulation of 76.7 parts (g/cm ² , MI=6) was applied by melt extrusion. The results obtained are shown in Table 4.

【table】

[Table] From Table 4, the resin composition containing 3 parts by weight of zinc stearate and 25 ppm of antioxidant (Sample No. 21) shows that both die lip stain and microgrit are extremely well prevented. hand,
A support suitable for photography was obtained. On the other hand, samples containing 3 parts by weight of calcium stearate or stearic acid and 25 ppm of antioxidant (Sample No.
22, No. 23) had a significant amount of die lip stain and microgrit, and was unsuitable as a photographic support. Example 5 Using each masterbatch described in Example 1 and Table 1, the resin composition at the time of melt extrusion was
30 parts by weight, ethylene-propylene copolymer (propylene content 0.1% by weight, density 0.945g/cm ³ , MI=
7) 30 parts by weight and low density polyethylene (density 0.92
Example 1 was repeated except that a resin composition containing 40 parts by weight (g/cm ³ , MI=7) was used. As a result, the same results as in Example 1 were obtained. Example 6 A masterbatch was prepared in the same manner as in Example 3 except for the composition of the masterbatch described in Table 3 and Note 3 of Example 3 except for ultramarine (white
(abbreviated as MB). Example 1 Except for using the above white MB and the masterbatch of samples No. 18 and No. 20 described in Example 3 Table 3 Note 3, and the resin composition during melt extrusion described in Table 5 Note 7. It was done in the same way as 1. The results obtained are shown in Table 5.

[Table] In Example 6, when preparing a masterbatch, the amount of titanium dioxide pigment, amount of ultramarine, zinc stearate and Comparisons were made using the same antioxidants, and sample No. 24, which is a photographic resin composition according to the present invention, was found to be suitable as a photographic support because it was extremely well prevented from forming die lip stains and microgrits. was gotten. On the other hand, sample No. 25, which is outside the scope of the present invention,
This resulted in a large amount of die lip stain and microgrit, and the resulting support was unsuitable for use as a photographic support. Example 7 The low density polyethylene for antioxidant kneading in Example 1 had a density of 0.926, an MI of 6, and
The antioxidant in Example 1 was 4.4′-thiobis-
Polyethylene resin-coated paper was produced in the same manner as in Example 1 with the formulations shown in Table 6, except that (6-tert-butyl-O-cresol) was used instead. applying a color emulsion adjacent to the resin layer surface containing the titanium dioxide pigment of the resin-coated paper so as to form a blue-sensitive emulsion layer, a green-sensitive emulsion layer, and a red-sensitive emulsion layer in order from the bottom;
Dry. The coated samples were stored at 35°C and normal humidity for 3 days and at 50°C.
After storage for 7 days at 60% DEG C., the film was exposed to sensitometry for 0.3 seconds, followed by color development, bleaching, washing with water, and drying as described below, and the fog density was measured. Color development (33℃, 3 minutes 30 seconds) → Bleach fixing (1 minute
30 seconds) → Washing with water (3 minutes) The composition of each treatment solution is as follows. Color developer Sodium carbonate (monohydrate) 46.0g Anhydrous sodium sulfite 2.0g Potassium bromide 0.5g CD- 4.5g Sodium hexametaphosphate 0.5g Hydroxyamine sulfate 2.0g Fluorescent brightener 0.5g Benzyl alcohol 12c.c. Diethylene glycol 10c.c. Adjust the total volume to 1 with water, and adjust the pH to 1 with sodium hydroxide.
Adjust to 10.2. Bleach-fix solution Ferric complex salt of ethylenediaminetetraacetic acid 56g Disodium salt of ethylenediaminetetraacetic acid 2g Ammonium thiosulfate 60g Anhydrous sodium sulfite 20g Sodium acid sulfite 5g Disodium phosphate 12g Adjust the total amount to 1 with water. The results obtained are shown in Table 6.

[Table] From Table 6, when 100 parts by weight of the resin composition contains 30 parts by weight of TiO ₂ and 1 part by weight of ultramarine, and 1.5 parts by weight of zinc stearate, the antioxidant Items that should not be included (sample no.
26) and the one containing 500 ppm of antioxidant (sample No. 35) both had high fog density after storage at 50°C, 60%, and 7 days, making them unsuitable as photographic supports. I understand. On the other hand, those containing 5 to 150 ppm of antioxidant (sample No. 27 to 34)
It can be seen that the occurrence of fogging is well prevented.
Furthermore, it was found that the prevention was even better when the content was 5 to 100 ppm.

Claims (1)

[Scope of Claims] 1. A resin composition mainly containing low density polyethylene and titanium dioxide pigment,
A method for producing a photographic resin composition, comprising 0.05 to 10 parts by weight of ultramarine, 5 to 150 ppm of an antioxidant, and 0.1 to 5 parts by weight of zinc stearate and/or magnesium stearate in 100 parts by weight. 2. The method for producing a photographic resin composition according to claim 1, wherein the antioxidant is a hindered phenol type antioxidant.