JPH06342194A - Supporting body for photographic paper - Google Patents

Abstract

PURPOSE:To provide a supporting body for photographic paper excellent in production aptitude, covering performance, sharpness and adhesive strength. CONSTITUTION:In the supporting body for photographic paper provided with a water resistant resin coating layer on both faces of a paper, (1) the water resistant resin coating layer of the emulsion coating side is composed of >=2 layers of a multilayered water resistant resin coating layer. (2) a water resistant resin containing 20-50wt.% titanium dioxide is melted and extruded on the upper layer at a low temp. (170-290 deg.C) and a water resistant resin containing a powder of 0.1-30wt.% such as talc, kaolin, calcium carbonate is melted and extruded on the lowermost layer at a high temp. (290-340 deg.C).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographic paper support, and more particularly to a photographic paper support capable of high-speed melt extrusion coating of a water-resistant resin having a high content of titanium dioxide on paper or synthetic paper. .

[0002]

2. Description of the Related Art The essential constitution of a photographic printing paper support is generally known, for example, US Pat.
As disclosed in Japanese Patent No. 1,298, both sides of a paper substrate are coated with a resin, and a water resistant resin coating layer on the emulsion coating side includes a titanium dioxide pigment and a bluing agent (including a blue filter pigment). ), Those containing a fluorescent whitening agent and the like are known. The addition of the titanium dioxide pigment is indispensable in order to increase the hiding property of the water-resistant resin coating layer and to obtain a photographic printing paper support having high sharpness. Moreover, recently, there is a strong demand for a support for photographic printing paper having a higher sharpness, and there is a strong demand for increasing the amount of titanium dioxide pigment added.

Conventionally, the concentration of titanium dioxide (TiO ₂ ) in the water resistant resin coating layer is 9 wt% to 15 wt%.
It is melt extrusion coated at a temperature of 0 ° C to 340 ° C. When the amount of TiO ₂ added is increased, the number of streaks (hereinafter referred to as die lip streak) generated in the die lip portion of the extruder is increased, and when the TiO ₂ concentration exceeds 20 wt%, gas streaks and film cracks are generated in the melt extruded film. There's a problem.

It is considered that the streak is caused by the partial accumulation or baking of the melt in the die lip portion. When such a die lip streak is generated, the film or laminate produced by the streak is produced. The surface has continuous stripes in the vertical direction. There are generally two types of streaks, one of which is a protrusion and the other of which is a depression. Such a die lip streak not only impairs the appearance of the product, but also causes unevenness in the transparency of the film during secondary processing such as stretching, resulting in a marked decrease in commercial value. Moreover,
To completely eliminate the die lip streak once occurred,
There is no method other than disassembling and cleaning the die lip, and disassembling and cleaning the die lip requires a great deal of labor and time, resulting in a marked decrease in productivity, and there is a need to solve the problem.

Various methods for preventing die lip streaks have hitherto been studied. For example, from the viewpoint of improving the resin composition,
A method in which a specific amount of zinc oxide and a metal salt of a higher resin acid are used in combination (JP-A-53-102947), and a method in which a dry weight loss of titanium dioxide and a specific amount of a fatty acid metal salt are used in combination (JP-A-57). No. 16819), a method in which a specific amount of an antioxidant and a fatty acid metal salt are used in combination (JP-A-60-11841), titanium dioxide dry weight loss, fatty acid metal salt, composition melt viscosity and other conditions are selected. Used in combination (Japanese Patent Publication No. 59-4
2296). Further, as the amount of titanium dioxide used increases, stains and grit frequently occur, so that it is necessary to modify the titanium dioxide, and therefore, the surface of the titanium dioxide is treated with hydrous aluminum oxide (JP-A-57-57). No. 108849), a method of treating with a dihydric to tetrahydric alcohol (Japanese Patent Laid-Open No. 58-17433).
JP-A No. 57-151942) or a method of treating with organic aluminum (JP-A No. 62-141544),
Alternatively, a method of reducing the loss on drying of titanium dioxide to 0.35% or less (JP-A-59-1544 and JP-A-59-12).
1329, JP-A-59-215234),
Also, many proposals have been made such as a method for controlling the electric conductivity of titanium dioxide suspension to 60 mho / cm or less (Japanese Patent Laid-Open No. 220-140140).

However, it is not sufficient as a method for preventing die lip streaks. Further, when the amount of titanium dioxide in the water resistant resin is increased, there is a problem that film cracking occurs in the melt-extruded film, and the TiO ₂ content in the water resistant resin in the existing photographic paper support is 15 wt% or less. Is.

[0007]

The object of the present invention is to enable melt extrusion coating without causing film cracking even when the content of titanium dioxide in the water-resistant resin is increased, and it has high concealing property and sharpness. It is also intended to provide a support for photographic printing paper which has the above-mentioned properties, has less occurrence of die lip streaks, and has good adhesion between the water-resistant resin coating layer and paper or synthetic paper.

[0008]

SUMMARY OF THE INVENTION The present invention provides a photographic printing paper support having a water-resistant resin coating layer on both sides of paper or synthetic paper, wherein the water-resistant resin coating layer on the emulsion coating layer side is at least 2. The water resistant resin having a titanium dioxide content of 25 wt% to 50 wt% is extruded at a low temperature of 170 ° C to 290 ° C, and the water resistant resin of the lowermost layer is 290 ° C to 340 ° C. Melt-extrusion coating at a high temperature of 0.1 wt% to 30 wt% of talc and / or kaolin and / or calcium carbonate in the lowermost layer of the water resistant resin coating layer. This was achieved by making the MI of the upper layer waterproof resin higher than that of the lowermost layer waterproof resin.

As the water-resistant resin, polyolefin such as polyethylene, polypropylene, polyester-based copolymer, etc., and particularly preferably polyethylene is used. As the polyethylene, high density polyethylene, low density polyethylene, linear low density polyethylene and blends of these polyethylenes can be used. The melt index (MI) of polyolefin resin before processing is JISK 7210.
1 g / 10 min-100 in the value measured under the condition 4 in Table 1 of
It is in the range of g / 10 minutes. MI before processing of the polyolefin resin described in this specification means a bluing agent, TiO.
MI of resin before kneading ₂ and M before use of diluted resin
I is shown. Since the lowermost layer of polyethylene is melt extruded at 290 to 340 ° C, or the intermediate layer and / or the upper layer of polyethylene is melt extruded at a low temperature of 175 to 290 ° C, a uniform resin film cannot be obtained if there is no fluidity between them. I can't get it. In order to obtain a uniform resin film with matching fluidity, the MI of the polyethylene of the intermediate layer and / or the upper layer is higher than that of the polyethylene of the lowermost layer.

The titanium dioxide (TiO ₂ ) contained in the water-resistant resin layer may be either anatase type or rutile type, but when priority is given to whiteness, anatase type TiO _{2 is used.}
, And rutile type TiO ₂ is preferable when the sharpness is prioritized. Anatase type and rutile type TiO ₂ may be blended and used in consideration of both whiteness and sharpness.
The anatase type may be used for one layer of the multi-layered water-resistant resin layer, and the rutile type TiO ₂ may be used for the other layer.

The TiO ₂ used generally has a surface-treated surface with an inorganic substance such as aluminum oxide hydroxide and silicon oxide, a polyhydric alcohol and a polyamine in order to suppress the activity of TiO ₂ and prevent yellowing. It is possible to use those surface-treated with an organic substance such as metal soap, alkyl titanate and polysiloxane, and those surface-treated with an inorganic / organic treatment agent in combination. The amount of surface treatment is 0.2 wt% to 2.0 wt% for inorganic substances and 0.1 wt% for organic substances with respect to TiO ₂ .
% -1.0 wt% is preferable. The particle size of TiO ₂ is preferably about 0.1 μm to 0.4 μm.

Ti of the upper layer in the multilayer waterproof resin coating layer
The O ₂ concentration is preferably 20 wt% to 50 wt%. Two
When it is less than 0% by weight, a support for photographic printing paper having a high sharpness cannot be obtained (the conventional sharpness cannot be exceeded). Further, the TiO ₂ concentration of the lowermost layer is lower than the concentration of the upper layer and is 15 wt%
Hereafter, it is not necessary to contain TiO ₂ .

TiO ₂ is water resistant in a kneader such as a two-roll, three-roll, kneader or Banbury mixer using a metal salt of higher fatty acid, higher fatty acid ethyl, higher fatty acid amide or higher fatty acid as a dispersion aid. A masterbatch which is kneaded into a resin and formed into a pellet shape is used.
The TiO ₂ concentration in the pellet is generally 30 wt% to 75 wt%
Dispersion aid is generally less than 0.1% based on the amount of TiO ₂ .
It is about 5 wt% to 10 wt%.

Further, the water resistant resin layer may contain a bluing agent. As the bluing agent, generally known ultramarine blue, cobalt blue, cobalt oxide phosphate, quinacridone pigments and the like and mixtures thereof are used. The particle size of the bluing agent is not particularly limited, but the particle size of the commercially available bluing agent is usually about 0.3 μm to 10 μm, and if the particle size is within this range, there is no particular problem in use. The content of the bluing agent in the multilayer waterproof resin layer in the present invention is preferably 0.2 wt% to 0.4 wt% in the uppermost layer and 0 to 0.15 wt% in the lower layer side.

The bluing agent is kneaded into a water-resistant resin with a kneading machine such as a two-roll, three-roll, kneader, Banbury mixer, etc. and molded into pellets to obtain a masterbatch. The concentration of the bluing agent in the pellet is 1 wt% to 30 wt%.

When making pellets of the bluing agent, T
It is also possible to knead iO ₂ together, and to help disperse the bluing agent, a low molecular weight water resistant resin, higher fatty acid metal salt, higher fatty acid ester, higher fatty acid amide,
Dispersion aids such as higher fatty acids can be used.

Further, an antioxidant may be contained in the water resistant layer of the present invention, and the content thereof may be 50 ppm to 1000 ppm based on the amount of the water resistant resin.

The masterbatch containing the titanium dioxide and / or the bluing agent thus produced is appropriately diluted with a water resistant resin for application.

Next, the talc and / or kaolin and / or calcium carbonate contained in the lowermost water-resistant resin layer preferably has an average particle size of 0.01 μm to 1.0 μm,
More preferably, it is 0.1 μm to 0.5 μm. If the average particle size is less than 0.01 μm, dispersion is difficult and 1.0 μm
If it exceeds m, the surface condition of the coated surface deteriorates. The amount of addition is 0.1 wt% to 30 wt%, preferably 1.0
It is preferable to set the content in the range of wt% to 20% by weight. If it is 1.0% by weight or less, desired adhesion will not be exhibited, and if it exceeds 30% by weight, whiteness will be lowered. The added particles may be either talc and / or kaolin and / or calcium carbonate, but talc is preferred. Other inorganic particles such as BaSO ₄ , Zn
_{O, TiO 2, ZnS, MgCO} 3, when compared with carbon, talc and / or kaolin and / or calcium carbonate of the present application has the effect of significantly adhesion improving the base paper layer.

As the method for forming the multi-layered waterproof resin layer in the present invention, pellets containing the above-mentioned titanium dioxide and / or the bluing agent which have been melted by heating are melted on a running substrate such as paper or synthetic paper, and it is also necessary. It is formed by diluting with a heat-resistant resin and melting, and then by a sequential laminating method or a laminating method using a multi-layer extrusion die of a foot block type, a multi-manifold type or a malte slot type. The shape of the multilayer extrusion die is generally a T die, a coat hanger die, etc., and is not particularly limited.

Before the resin is coated on the substrate, it is preferable to subject the substrate to activation treatment such as corona discharge treatment, flame treatment, glow discharge treatment and the like.

Taking the case of a two-layer structure as the multilayer waterproof resin layer of the present invention, for example, if the upper layer containing high concentration TiO ₂ has a film thickness of 2 μm to 40 μm and less than 2 μm, film forming is difficult. In addition, the amount of TiO ₂ decreases and the sharpness also decreases. It is preferably 10 μm to 30 μm. The thickness of the lower layer is 2 μm to 20 μm, preferably 5 μm to 1
5 μm is good.

The outermost surface of the water-resistant resin layer on the side to which the emulsion is applied has a glossy surface or a fine surface, a matte surface or a silky surface described in JP-A-55-26507.
The back side should be matte. An activation treatment such as a corona discharge treatment or a flame treatment can be applied to the surface after molding, and after the activation treatment, an undercoating treatment as described in JP-A-61-84643 can be performed.

The substrate used in the present invention includes natural pulp paper containing normal natural pulp as a main component, mixed paper containing natural pulp and synthetic fibers, synthetic fiber paper containing synthetic fibers as a main component, polystyrene and polypropylene. Any of so-called synthetic papers obtained by making synthetic resin films into pseudo papers, etc., but natural pulp papers (hereinafter simply referred to as base papers) are particularly preferably and advantageously used as the base of polyolefin resin-coated papers for photographic printing papers. To be As additive chemicals, in addition to alkyl ketene dimer, fillers such as clay, talc, calcium carbonate, urea resin fine particles, rosin, higher fatty acid salt, paraffin wax, sizing agents such as alkenyl succinic acid, paper strengthening agents such as polyacrylamide The one to which a fixing agent such as sulfuric acid band is added is used. Other,
If necessary, dyes, fluorescent dyes, slime control agents, defoaming agents, etc. are added. Further, the following softening agents can be added as required.

With respect to the softening agent, for example, New Paper Processing Handbook (edited by Paper Medicine Times Co.), pages 554 to 555, 1980.
There is a description in the yearly issue. Particularly, those having a molecular weight of 200 or more are preferable. That is, having a hydrophobic group having a carbon number of 10 or more,
It also has an amine salt or quaternary ammonium salt that self-fixes with cellulose. Specifically, a reaction product of a maleic anhydride copolymer and a polyalkylene polyamine, a reaction product of a higher fatty acid and a polyalkylene polyamine, a reaction product of a urethane alcohol and an alkylating agent, a higher fatty acid 4
Examples thereof include primary ammonium salts, and a reaction product of a maleic anhydride copolymer with a polyalkylene polyamine and a reaction product of a urethane alcohol with an alkylating agent are particularly preferable.

The pulp surface may be surface-sized with a film-forming polymer such as gelatin, starch, carboxymethyl cellulose, polyacrylamide, polyvinyl alcohol, or a modified product of polyvinyl alcohol. Examples of the modified polyvinyl alcohol in this case include a modified carboxyl group, a modified silanol, and a copolymer with acrylamide. The coating amount of the film-forming polymer in the case of surface sizing treatment with a film-forming ^{polymer, 0.1g / m 2 ~5.0g / m} 2, preferably in 0.5g / m ² ~2.0g / m ² Adjusted. Furthermore, an antistatic agent, a fluorescent whitening agent, a pigment, an antifoaming agent, etc. can be added to the film-forming polymer at this time, if necessary.

The base paper is prepared by using a pulp machine containing the above-mentioned pulp and additives such as a filler, a sizing agent, a paper-strengthening agent, and a fixing agent, which are optionally added, by a paper machine such as a Fourdrinier paper machine. Manufactured by paper making, drying and winding. The surface size treatment is performed before or after the drying, and the calender treatment is performed between the drying and the winding. When the surface sizing treatment is performed after drying, this calendering treatment can be carried out either before or after the surface sizing treatment, but it is preferable to carry out the calendering treatment in the final finishing step after various treatments have been carried out. . In the calendering process, known metal rolls and elastic rolls that are commonly used in the production of paper are used.

The base paper used for the photographic printing paper support of the present invention is subjected to the above-mentioned calendering treatment and finally 50
The film thickness is adjusted to μm to 250 μm. The density of the base paper is 0.8 g / m ^{3 to} 1.3 g / m ³ , preferably 1.0.
a ^{g / m 3 ~1.2g / m 3} .

The photographic support of the present invention may be coated with various back coat layers for the purpose of preventing electrification and curling. In addition, Japanese Patent Publication Sho 52
-18020, Japanese Patent Publication No. 57-9059, Japanese Patent Publication No. 57
No. 53940, Japanese Patent Publication No. 58-56859, and Japanese Patent Laid-Open No. 5
No. 9-214849, JP-A No. 58-184144 and the like, or an inorganic antistatic agent, an organic antistatic agent, a hydrophilic binder, a latex, a curing agent, a pigment, a surface active agent and the like are appropriately combined. It can be included.

The photographic support according to the present invention is coated with various photographic constituent layers and is used for color photographic printing paper, black-and-white photographic printing paper, typesetting photographic paper, photographic printing paper, reverse photographic material, The silver salt diffusion transfer method can be used for various purposes such as negative and positive, 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 color photographic constituent layer. Further, a silver salt diffusion transfer image-receiving layer can be provided by containing a physical phenomenon nucleus.

The present invention relates to a photographic paper support having a water-resistant resin coating layer on both sides of paper or synthetic paper, and at least contains a high concentration of TiO ₂ in the water-resistant resin coating layer on the emulsion coating layer side. In a support for photographic printing paper having a multilayer waterproof resin layer composed of two or more layers and a method for producing the same, a die lip streak and a gas streak generated when melt-extruding a waterproof resin containing a high concentration of TiO ₂ It was found as a result of earnest studies to eliminate film cracks and enable high-speed melt extrusion coating.

In the present invention, the detailed mechanism of elimination of the film crack is not clarified, but this film crack is caused by high concentration TiO ₂ at the usual melt extrusion coating temperature of 290 ° C to 340 ° C.
When melt-extruding a water-resistant resin containing TiO ₂ , water and a volatile component contained in TiO ₂ and a surface treatment agent for TiO ₂ are gasified in the extruder or when discharged from the die lip. It is considered that the molten film is cracked by the gas, and as a result, film cracking occurs in a low concentration region as TiO _{2 having} a large amount of water and volatile matter. In addition, the concentration of TiO ₂ is set to 25
When it is increased to more than wt%, the die lip streaks suddenly increase, which is considered to be because the water resistant resin is easily oxidized by the presence of TiO ₂ .

On the other hand, in the photographic printing paper support according to the present invention, the melt extrusion temperature at the time of melt extrusion coating the water resistant resin containing a high concentration of TiO ₂ is 170 ° C.
By lowering the temperature to 290 ° C., TiO ₂ and TiO ₂
It is possible to suppress the gasification of water and volatile components contained in the surface treatment agent of (1) above and to extrude a uniform water-resistant resin film containing a high concentration of TiO ₂ without gas streaks and film cracks. Further, by lowering the melt extrusion temperature, it is possible to simultaneously reduce the oxidation of the water resistant resin and prevent die lip streaks. However, in this low temperature melt extrusion, the flowability of the water resistant resin is poor and high speed melt extrusion coating cannot be performed, and at the same time, the adhesion between the water resistant resin coating layer and the paper or the synthetic paper deteriorates.

In the support for photographic printing paper according to the present invention,
MI of water resistant resin containing high concentration of TiO ₂ is 2 g /
High-speed melt extrusion coating was made possible by improving flowability even at low temperature melt extrusion by 10 minutes to 100 g / 10 minutes, preferably 20 g / 10 minutes to 80 g / 10 minutes. Further, the adhesion between the water resistant resin coating layer and the paper or the synthetic paper is determined by adjusting the melt extrusion temperature of the lowermost layer to a normal temperature of 290
Adhesion can be improved by adding a filler such as talc and / or cation at a temperature of from 340 to 340 ° C. In this manner, the high sharpness photographic paper support having the water resistant resin coating layer containing a high concentration of TiO ₂ in the present invention can be subjected to high speed melt extrusion coating.

[0035]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.

Example 1 Polyethylene having a basis weight of 170 g / m ² and polyethylene having a density of 0.92 g 5 / cm ³ and an MI of 8 g / 10 min was used in a first laminating station at a film thickness of 28 μ and 200 m / min. The polyethylene layer. Then, at the second station, on the other side of the base paper, 40 wt% of TiO ₂ was added to the upper layer, T
Density 0.925 g / cm ³ , MI = 20 g / 10, containing 1.5 wt% of zinc stearate as a dispersant for iO _2.
Min polyethylene, extrusion temperature 250 ℃, film thickness 15μ,
The lower layer contains 10 wt% talc and has a density of 0.925 g /
cm ³ , MI = 2 g / 10 min polyethylene, extrusion temperature 320 ° C., film thickness 15 μ, upper and lower layers combined 30 μ When laminated at 200 m / min by multi-layer extrusion, film cracking did not occur and adhesion with the base paper was 300 g- 400g / 15mm width (using Tensilon, 5kg load cell speed 50mm
/ Min, peel strength of 180 °), which was the same level as the conventional 320 ° C. single layer extrusion laminate. No occurrence of die lip streaks was observed even after 8 hours of operation.

Comparative Example 1 As conditions for the second station in the above embodiment, the polyethylene in the above embodiment was 40 wt% of TiO ₂ and T.
Polyethylene containing 1.5 wt% zinc stearate as a dispersant for io ₂ having a density of 0.925 g / cm ³ , MI = 2 g / 10 min, extrusion temperature of 320 ° C., and a single layer lamination of a film thickness of 30 μ A uniform polyethylene coating layer could not be formed due to cracking and die lip streaks.

Comparative Example 2 As the conditions for the second station in the above example, the same composition as the polyethylene layer of the upper layer in the above example was used, and the extrusion temperature was 250 ° C., the film thickness was 30 μm, and the film thickness was 200 m / min. When a single layer lamination was performed for a minute, the lamination could not be continued due to the peeling of the film between the base paper and the polyethylene layer.

Comparative Example 3 As the conditions for the second station in the above example, the upper layer of polyethylene MI = 2 g / 10 min in the above example was changed to an extrusion temperature of 320 ° C. and a film thickness of 15 μ,
The lower layer was the same as in the above example, and when the upper and lower layers were laminated at a rate of 200 m / min by 30 μ multilayer extrusion, film cracking occurred in the upper layer and a uniform polyethylene coating layer could not be formed.

Example 2 Similar to Example 1, the same laminating station
And basis weight 170g / m²Density of 0.925g / cm
³With MI, polyethylene with a film thickness of 28g
One side of base paper is coated with polyethylene layer at 200m / min
It Then, on the other side of the base paper at the second station,
TiO at the ratio shown in Table 1 ₂And also steari
Zinc oxide in TiO₂It is contained at a ratio of 5.0 wt% to the amount.
And knead in a Banbury mixer, then form into pellets
Then, the masterbatch was adjusted. TiO₂Is an electron microscope
Hydrated acid with an average particle size of 0.15 μm to 0.35 μm
Aluminum aluminum coating amount is Al₂O₃In the form of T
iO₂In contrast, 0.35 wt% was used. Density 0.9
25 g / cm³, MI = 20 g / 10 min polyethylene,
Extrusion temperature: 250 ° C, lower layer contained 10 wt% of talc
Density 0.925g / cm³, MI = 2g / 10min.
Extrusion temperature of 320 ° C, upper and lower layers with film thickness shown in Table 1
A two-layer polyethylene coating layer was provided at 200 m / min. Next
In addition, the surface of this polyethylene layer is treated with glow discharge and then chlorinated.
A silver emulsion was applied to obtain a photographic printing paper. The obtained photographic printing paper
The resolution chart is closely attached to the
Image processing was performed to obtain a test sheet. This test sheet
Measure with an ice densitometer and follow the
Image sharpening of magenta layer calculated by null computer
CTF (Contrast Transfer Function)
Photograph of the last transmission function, 10 lines / mm)
The sharpness of the printed image of the resin-coated paper for use was judged. Na
The higher the value of CTF, the sharper the printed image.
It shows that the degree is high.

[0041]

[Table 1]

The results are shown in Table 1. As can be seen from Table 1, the support for photographic printing paper of the present invention has a high sharpness of a printed image.

Example 3 As in Example 1 above, at the first laminating station,
One side of the base paper is coated with a polyethylene layer having a thickness of 28 μm, and then at the second station, the other side of the base paper is covered with the upper layer TiO
₂ Polyethylene containing 15 wt% MI = 20 g / 10 min, extrusion temperature 320 ° C., film thickness 15 μm, talc in the lower layer was varied between 0 and 30 wt% MI = 2 g / 1
0 minutes polyethylene, extrusion temperature 320 ° C, film thickness 15μ
A two-layer polyethylene coating layer was provided at m 2 of 200 m / min.
Further, before the two-layer polyethylene coating, the same two-layer polyethylene coating was applied to the surface of the raw paper which was subjected to corona discharge treatment. In order to measure the adhesion between the two-layer polyethylene coating layer and the base paper, a Tensilon was used for a 15 mm wide sample, a load cell of 5 kg, a speed of 50 mm / min, and a peeling angle of 18
The peel strength at 0 ° was measured. The results are shown in Table 2. Table 2
As can be seen, the addition of talc improves the adhesion between the polyethylene coating layer and the base paper.

[0044]

[Table 2]

Front page continuation (72) Inventor Yasuo Nishikawa 200, Onakazato, Fujinomiya-shi, Shizuoka Fuji Photo Film Co., Ltd.

Claims (3)

[Claims] 1. A photographic printing paper support having a water-resistant resin coating layer on both sides of paper or synthetic paper, wherein the water-resistant resin coating layer on the emulsion coating layer side is a multilayer water-resistant resin coating layer of two or more layers. The upper layer is composed of titanium dioxide content of 20 wt% to 50%
A photographic paper support characterized in that a wt% water resistant resin is extruded at a low temperature of 170 ° C. to 290 ° C. and a water resistant resin of the lowermost layer is melt extrusion coated at a high temperature of 290 ° C. to 340 ° C. 2. A support for photographic printing paper, characterized in that the lowermost layer of the waterproof resin coating layer contains 0.1 wt% to 30 wt% of talc and / or kaolin and / or calcium carbonate. 3. A support for photographic printing paper, characterized in that in the water resistant resin coating layer, the MI of the upper water resistant resin is higher than the MI of the lowest water resistant resin.