JPH0843992A - Support photographic printing paper and its manufacture - Google Patents

Abstract

PURPOSE:To provide a support for photographic printing paper which is little permeable by developer at development and which is excellent in bonding force between base paper and a polyolefine. CONSTITUTION:This is a support for photographic printing paper being constituted by covering both sides of base paper with polyolefine resin, and here the base paper contains kaochinized starch 0.1wt.% or over in nitrogen content and alkylketenedimer and/or epoxidated high-class fatty acid amide, and cooling water extraction pH is 6.0-7.5 or over, and also the bonding strength between the base paper and a polyolefine resin film is 320g or over.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographic printing paper support, and more particularly, to a photographic printing paper support in which the adhesive force between a base paper and a polyolefin resin is remarkably improved and which is excellent in production suitability, development treatment suitability and processing suitability. The present invention relates to a body and a manufacturing method thereof.

[0002]

2. Description of the Related Art In recent years, as a support for photographic printing paper, polyethylene is used on both sides of the base paper in order to prevent permeation of a processing solution at the time of developing and fixing a photograph and to shorten the time of washing and drying. Coated with a polyolefin of
Water resistant photographic paper supports are preferred.

On the other hand, with regard to the base paper, an anionic sizing agent, an anionic strength enhancer, and an inexpensive aluminum salt for fixing these anionic chemicals to the pulp are added to the stock in the papermaking process. As a result, so-called acid paper has been used, which exhibits acidity. However, neutral paper, which is advantageous in terms of improving the preservability of base paper, closing white water in the paper making process, and preventing corrosion of equipment,
In recent years, it has become widely used in general paper.

By the way, as the base paper for photographic paper support,
In order to prevent the permeation of the developing solution from the cut surface of the support during the development processing, it is necessary that the paper be strong size.
Therefore, when neutral paper is used as the base paper for photographic paper, self-fixing alkyl ketene dimer, epoxidized higher fatty acid amide, etc. are used as the sizing agent, and as the paper strength agent, kaothene is used. Polyacrylamide, chaotic starch, and polyamide polyamine epichlorohydrin are used. In this case, the pH of the stock is adjusted to 6.0 to 9.0 for papermaking.

[0005] Papermaking base paper is usually produced by coating the surface thereof with an aqueous solution (size) containing polyvinyl alcohol or starch as a main component by a size press or the like, and drying it to prepare a photographic paper support. Used as the base paper for. However, when the amount of the size liquid applied is small, there is a drawback that the adhesive force between the base paper and the polyolefin resin is reduced.

On the other hand, natural pulp is used as a main raw material, and if necessary, filler such as clay, talc, calcium carbonate, urea resin fine particles, rosin, alkyl ketene dimer, higher fatty acid, epoxidized fatty acid amide, paraffin wax,
A sizing agent such as alkenyl succinic acid, starch, a paper-strengthening agent such as polyamide polyamine epichlorohydrin, polyacrylamide, etc., a base paper formed by adding a fixing agent such as a sulfuric acid band or a cationic polymer, and polyester or polyester coated on the surface thereof. In order to enhance the adhesion to the mixed composition with the pigment, the surface of the raw paper is flame-treated, and the ratio (O / C) of oxygen and carbon counts by the X-ray photoelectron spectroscopy (ESCA) of the surface is 1 A method of setting the value of 1 or more has been proposed (Japanese Patent Laid-Open No. 6-110152).

[0007] The inventors of the present invention have found that when the above method is carried out in the same manner and polyethylene is used instead of polyester, the adhesion (adhesion) is not always sufficient. The inventors of the present invention have made further detailed investigations and found that the nitrogen content is not 0, which does not use a sulfuric acid band and is not usually classified as a chaotic polymer.
It is possible to obtain extremely good results by using a base paper to which 1% by weight or more of chaotenized starch is added and setting the O / C of the base paper surface to 1.0 or more immediately before coating with the polyolefin resin. Found and arrived at the present invention.

[0008]

SUMMARY OF THE INVENTION It is, therefore, a first object of the present invention to provide a support for photographic printing paper, which has a small penetration of a developing solution at the time of development and has an excellent adhesive force between a base paper and a polyolefin. . A second object of the present invention is to provide a support for photographic printing paper, which has a high adhesive force between the base paper and the polyolefin and is excellent in manufacturing suitability and processing suitability. A third object of the present invention is to provide a method for producing a support for photographic printing paper, which has less penetration of a developing solution at the time of development and has excellent adhesive force between a base paper and a polyolefin.

[0009]

The above-mentioned various objects of the present invention are a support for photographic printing paper comprising a base paper coated on both sides with a polyolefin resin, the base paper having a nitrogen content of 0.1. % By weight of chaotic starch, and alkyl ketene dimer and / or epoxidized higher fatty acid amide, and cold water extraction pH of 6.0 to 7.5,
This has been achieved by a support for photographic printing paper and a method for producing the same, which has an adhesive force of 320 g or more between the base paper and the polyolefin resin film.

The present invention will be described in more detail below. The base paper used for the support for photographic printing paper of the present invention is obtained by making a paper from a stock containing natural pulp obtained from conifers, hardwoods and the like as a main raw material and various chemicals described below. In the present invention, instead of the above-mentioned natural pulp, a base paper in which synthetic pulp or the like is blended at an arbitrary ratio may be used. The beating degree of pulp is preferably CSF (Canadian Freeness) value of 200 ml to 400 ml, and particularly preferably 250 ml to 350 ml.

The chaotinated starch that can be used in the present invention is an ordinary starch such as corn starch, potato starch,
It can be obtained by adding a chaos group to tapioca starch, wheat starch, rice starch, sweet potato starch and the like. Methods for producing chaotic starch are known and can be easily prepared by introducing one or more basic nitrogens selected from primary, secondary, tertiary amine and quaternary ammonium groups into starch. Although it can be obtained, in the present invention, the nitrogen content is 0.1% by weight or more. In the present invention, it is particularly preferable to use a chaotic starch in which the basic nitrogen atom is a tertiary amine or a quaternary ammonium group.

The alkyl ketene dimer used in the present invention is a compound represented by the following chemical formula 1.

Embedded image R in the chemical formula 1 is an alkyl group, and the number of carbon atoms in R is preferably 8 to 30, particularly preferably 12 to
20 and most preferably 20. The above-mentioned alkyl ketene dimer is preferably added to the pulp slurry as an emulsified dispersion obtained by emulsifying and dispersing with the chaotic starch and / or the surfactant. The surfactant can be appropriately selected and used from known ones. The amount of the alkyl ketene dimer added is 0.05% by weight to 5% by weight, and preferably 0.1% by weight to 1.5% by weight, based on the dry pulp.

The epoxidized higher fatty acid amide used in the present invention acts as a sizing agent, and specific examples thereof include, for example, Japanese Examined Patent Publication Nos. 38-20601 and 39.
-4507 and U.S. Pat. No. 3,692,092
Obtained by the condensation of a fatty acid and a polyvalent amine as described in JP-A-51-1705, and those obtained by the reaction of an alkenylsuccinic acid and a polyvalent amine as described in JP-A-51-1705. Etc. can be mentioned.

In the present invention, among the above fatty acids, aliphatic monocarboxylic acids and polyvalent carboxylic acids having 8 to 30 carbon atoms are preferable, and those having 12 to 25 carbon atoms are particularly preferable. Specific examples of such aliphatic carboxylic acid include stearic acid, oleic acid, lauric acid, palmitic acid, arachidic acid, behenic acid, tall oil fatty acid, alkylsuccinic acid, alkenylsuccinic acid and the like. Of these, behenic acid is particularly preferable.

The polyamine is preferably a polyalkylene polyamine, and more preferably one having 2 to 3 amino groups. Specific examples of the polyvalent amine include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, dipropylenetriamine, tripropylenetetramine, aminoethylethanolamine and the like.

The amounts of the aliphatic carboxylic acid and the polyvalent amine in the reaction are such that the amino groups are in excess of the carboxyl groups. In this case, in order to make the particles of the sizing agent finer, after the reaction of the aliphatic carboxylic acid and the polyvalent amine, if necessary, further modification is carried out by reacting with urea, adipic acid, maleic acid, phthalic acid, formic acid, formalin, etc. May be done, Japanese Patent Publication No. 42-2922, 45-28
As described in JP-A No. 722 and JP-A No. 50-116705, a rosin petroleum resin, an α, β-unsaturated polybasic acid-added rosin at the time of a reaction between an aliphatic carboxylic acid and a polyvalent amine, The modification may be carried out by reacting the α, β-unsaturated polybasic acid-added petroleum resin and the like together.
The materials used for modifying the chaotic sizing agent composed of these aliphatic carboxylic acids and polyvalent amines are used within a range that does not cause a decrease in whiteness or size.

In many cases, in order to make the reaction product of an aliphatic carboxylic acid and a polyvalent amine water-soluble or water-dispersible, it is salted with an inorganic acid and an organic acid, or an alkyl halide,
Modified with benzyl chloride, ethylene chlorohydrin, epichlorohydrin, ethylene oxide, etc.,
It is necessary to use a quaternary salt. A quaternary salt is desirable in order to maintain the chaos property in a wide pH range and to prevent the sizing agent from falling off from the pulp by mechanical stirring. In particular, the size effect is large when a quaternary salt is formed by a reaction with epichlorohydrin.

The amount of epoxidized higher fatty acid amide added is
It is 2.0% by weight or less based on absolute dry pulp, and can be appropriately adjusted in the range of preferably 0.1% by weight to 2.0% by weight. In the present invention, if necessary, various chemicals shown below can be added to the slurry for making the base paper.

As additives, clay, talc, calcium carbonate, fillers such as synthetic resin pigments, paper-strengthening agents such as chaotic polyacrylamides, amphoteric polyacrylamides and anionic polyacrylamides, wet paper-strengthening agents such as polyamide polyamine epichlorohydrin, etc. Examples thereof include agents, chaotic polymers such as diallylamine salts, anionic colloidal silica, anionic inorganic colloids such as anionic bentonite, anionic polymers such as carboxymethylcellulose, porvinyl alcohol, and oxidized starch.

As the pH adjusting agent for the paper material, a compound showing alkalinity is appropriately used. As such an alkali control agent, for example, sodium hydroxide, sodium aluminate, sodium hydrogen carbonate or the like can be used. Two or more of these compounds may be used in combination. The above-mentioned chaotic polyacrylamide obtained by the copolymerization of acrylamide and a chaotic monomer (hereinafter abbreviated as a copolymerization type chaotic polyacrylamide) has a molecular weight of 500 to 1,500,000 measured by GPC method (gel permeation chromatography). Preferred, especially 70
It is preferably from 1,000,000 to 1,000,000. Moreover, it is preferable that the chaos number is 1.5 to 5.0.

The chaotic monomer copolymerizable with acrylamide is preferably a compound represented by the following chemical formulas 2 and 3, or a salt thereof.

Embedded image

[Chemical 3] In the formulas 2 and 3, R ¹ represents a hydrogen atom or a lower alkyl group, R ² and R ³ represent a lower alkyl group, and n represents an integer of 1 to 5.

Specific examples of the above-mentioned chaotic monomer are shown below, but the present invention is not limited thereto. Dimethylaminoethyl methacrylate _{CH 2 = C (CH 3)} COOCH 2 CH 2 N (CH 3)
₂ diethylaminoethyl methacrylate _{CH 2 = C (CH 3)} COOCH 2 CH 2 N (CH 2 C
H ₃ ) ₂ dimethylaminoethyl methyl methacrylate methacrylate [CH ₂ ═C (CH ₃ ) COOCH ₂ CH ₂ N (C
H ₃ ) ₃ ] · Cl dimethylaminopropylacrylamide CH ₂ = CNCONHCH ₂ CH ₂ CH ₂ N (CH ₃ ).
₂

In the present invention, it is also possible to use a terpolymer obtained by copolymerizing acrylamide and a chaotic monomer with (meth) acrylic acid. For the measurement of the chaos number of the copolymer type kaitin type polyacrylamide, about 0.1 g of a sample was precisely weighed and diluted with a diluent (water / methanol / acetic acid = 89/10/1, volume ratio). N / 400 Polyvinyl potassium sulfate (PVSK)
It can be determined by titration with an aqueous solution and by the following formula.

Measured value (ml) × (1/400) × factor (PVSK) / sample amount (g) × (nonvolatile matter (%) / 100) Nonvolatile matter is 3.0 ± 0.2 g of the sample. Spread evenly on a Petri dish (50 mm x 15 mm) and weigh accurately.
After drying for 3 hours with a circulating air dryer at ± 5 ° C, put it in a desiccator, allow it to cool for 30 minutes, precisely weigh it to determine the remaining dry amount, and calculate it.

The amphoteric polyacrylamide which can be used as a chaotic substance in the present invention is an amphoteric polyacrylamide obtained by copolymerizing an anionic monomer and a chaotic monomer while using acrylamide or methacrylamide as a main monomer component. GPC, which is a copolymer
The average molecular weight measured by the method is preferably 2 to 5,000,000, and particularly preferably 2 to 3.5 million. Examples of the anionic monomer include acrylic acid, methacrylic acid, and itaconic acid. Among these, itaconic acid is particularly preferably used.

As the chaotic monomer copolymerizable with acrylamide, the dialkylaminoalkyl methacrylate represented by the above chemical formula 2 and its salt, and the above chemical formula 3
The dialkylaminoalkylacrylamides and salts thereof represented are preferred. The amphoteric polyacrylamide is used in an amount of 0.01 wt% to 0.5 wt% based on the dry pulp.
Is preferable, and 0.2% to 3.0% by weight is particularly preferable.

In the present invention, anionic polyacrylamide may be used. Anionic polyacrylamide that can be used is a terpolymer in which a part of acrylamide is partially substituted with acrylonitrile, acrylic acid ester, styrene, or the like, or a partial hydrolyzate of polyacrylamide. It is preferable to use a polymer having a molecular weight of 500,000 to 2,000,000, preferably 800,000 to 1,400,000 as measured in (4).

In the present invention, it is preferable to add polyamide polyamine epichlorohydrin as a wet paper strength agent in an amount of 0.1 to 1.0% by weight based on absolute dry pulp. The diallylamine salt used in the present invention, hydrochloric acid of diallylamine, sulfuric acid, inorganic acid salts such as phosphoric acid or formic acid,
Organic acid salts such as acetic acid and propionic acid are used.

The anionic colloidal silica and anionic bentonite used in the present invention are anionic inorganic colloids. Examples of such colloids include colloidal montmorillonite and bentonite, titanyl sulfate sol, silica sol, aluminum modified silica sol, or Examples thereof include aluminum silicate sol. The amount of the anionic inorganic colloid is in the range of 0.005% by weight to 1% by weight, preferably 0.01% by weight to 0.5% by weight, based on the dry pulp. If it is less than 0.005% by weight, the cohesive force of the pulp fiber is not sufficient and the expected effect is hardly obtained.

On the other hand, if it exceeds 1% by weight, agglomerates of pulp fibers are generated and the texture is disturbed, so that not only the appearance of the product but also the performance is remarkably lowered and the cost is increased, which is not preferable. The anionic colloidal silica takes the form of polysilicic acid or colloidal silicic acid sol, but the best results are obtained especially when the colloidal silicic acid sol is used. The specific surface area of the colloidal silica is preferably about 50 to about 1,000 m ² / g, the average particle size is 60 nm or less, preferably 20 nm or less, and particularly the average particle size of about 1 nm to about 10 nm. Is preferred.

The anionic bentonite is, if necessary,
It means a layered silicate that has an ultrafine viscosity and contains montmorillonite treated with an appropriate base as a main mineral and swells in water. The anionic bentonite used in the present invention contains thin plate-like particles, and preferably has a specific surface area of about 50 to about 1000 m ² / g.

In the present invention, the zeta potential is -15 m.
It is preferable to make the base paper from a V-5 mV stock (pulp slurry immediately before paper making). Zeta potential is -15 mV
If it is less than or more than +5 mV, the depth of penetration of the developing solution from the cut end face of the printing paper at the time of development becomes large, and a photographic printing paper that can be used cannot be obtained. The zeta potential of the pulp slurry can be adjusted by adding an anionic substance into the pulp slurry.
This is because pulp is generally an anion, but paper strength agents, sizing agents, etc., which are added to obtain the properties necessary for the neutral base paper for photographic paper, are preferably kaoth and also have a large addition amount. This is because the pulp slurry after the addition of the chemical usually has a positive potential.

In the present invention, a water-soluble anionic polymer can be used as the anionic substance.
Such water-soluble anionic polymer, especially, carboxymethyl cellulose and salts thereof, polyvinyl alcohol, carboxy-modified polyvinyl alcohol and salts thereof,
It is preferable to use at least one selected from the group consisting of polyacrylic acid and its salts, oxidized starch, and anionic polyacrylamide. A particularly preferred water-soluble anionic polymer is sodium salt of carboxymethyl cellulose.

In the present invention, in addition, dyes, optical brighteners, defoaming agents, etc. may be added. It is necessary to control the amount of the alkaline substance added so that the final pH of the paper stock is 6.0 to 9.0, in order to improve the preservability of the base paper and the preservability of the photographic paper support. Is preferred.
For example, an alkaline substance such as sodium hydroxide, sodium hydrogen carbonate, or sodium aluminate is added to control the pH in the neutral range of 6.0 to 9.0.

A hygroscopic substance such as glycerin or polyethylene glycol may be added to the liquid containing the water-soluble additive. In addition, a pigment or the like can be added to the aqueous solution, if necessary. Although the thickness of the base paper is not particularly limited, the basis weight is 50 g / m ^{2 to} 25.
0 g / m ² is desirable. Further, from the viewpoint of the flatness of the photographic printing paper, it is desirable to use a base paper having excellent surface smoothness and flatness. Therefore, it is preferable to use a machine calender, a super calender or the like to apply heat and pressure to the surface treatment.

In the present invention, the solution containing polyvinyl alcohol and / or starch as a main component is applied and dried on both sides of the base paper before forming the polyolefin resin coating layer on both sides of the base paper. It is preferable from the viewpoint of strengthening the adhesiveness with. Incidentally, this coating may be performed before the calendar treatment. In order for the polyvinyl alcohol and / or starch to be effectively adhered to the surface of the base paper, it is preferable that the water absorption of the base paper measured by the Cobb method specified in JIS P-8140 is 30 g / m ² or less, particularly 25 g. / M ² or less is preferable.

In the present invention, in coating the polyolefin resin, in order to strengthen the adhesiveness between the polyolefin resin and the base paper, the surface of the base paper substrate to be coated is subjected to a corona discharge treatment, a glow discharge treatment, a flame by a gas burner. Activation processing is performed in advance by processing or the like. By carrying out the above-mentioned activation treatment so that the O / C count ratio by ESCA of the surface of the base paper becomes 1.0 or more, the adhesive force between the base paper and the polyolefin coated on the surface can be 320 g or more. it can. The adhesive strength in this case is 180 ° adhesive strength of the polyolefin resin coating layer of Tensilon RTM-25 (trade name of Orientec Co., Ltd.) of the support for photographic printing paper cut out with a width of 1.5 cm ( (See FIG. 1).

Specific examples of the polyolefin resin that can be used in the present invention include homopolymers of α-olefins such as polyolefins including polyethylene, and mixtures of these various polymers. it can. Particularly preferred polyolefins are high density polyethylene, low density polyethylene and mixtures thereof. The molecular weight of these polyolefins is not particularly limited as long as it is possible to add a white pigment, a coloring pigment, or a fluorescent brightening agent in the extrusion-coated coating layer, but usually the molecular weight is 20,000-2
Polyolefins in the range of 0,000 are used.

There is no particular limitation on the thickness of the polyolefin resin coating layer, which can be determined according to the thickness of the polyolefin layer of the conventional printing paper support, but generally the thickness is about 15 to 50 μm. . In the polyolefin resin coating layer, a white pigment, a coloring pigment or a fluorescent whitening agent,
Stabilizers such as phenols, bisphenols, thiobisphenols, amines, benzophenones, salicylates, benzotriazoles and organometallic compounds can be added.

In particular, it is preferable to add a white pigment and a coloring pigment to the polyolefin resin coating layer on the side on which the photographic emulsion is coated. As the extrusion coating equipment for extrusion coating the polyolefin, a usual extruder for polyolefin and a laminator are used. The photographic paper support of the present invention has a glossy surface coated with a photographic emulsion layer and dried to give a photographic paper.
Various modes are possible on the other side, for example, a print preservation layer disclosed in JP-A-62-1256 can be provided.

[0041]

The base paper used for the support for photographic printing paper of the present invention contains chaotic starch, alkyl ketene dimer and / or epoxidized higher fatty acid amide and has a pH of 6 to 6.
Since the paper was made from the pulp slurry of No. 9 and the O / C of the surface of the base paper at the time of coating with the polyolefin resin was controlled to at least 1.0 or more, the adhesive force between the polyolefin resin and the base paper was 320 g / m ² It is strong as above. Therefore, the photographic printing paper using this raw paper is suitable as a support for photographic printing paper, since the penetration of the developing solution from the edge portion during development processing is small and the processability for panel attachment is significantly improved. Is.

If necessary, by applying a solution containing polyvinyl alcohol and / or starch as a main component on both sides, the adhesiveness between the base paper and the polyolefin resin can be further improved. The polyolefin resin can be easily coated on the surface of the base paper, which can greatly improve the production efficiency.

[0043]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.
In addition, the weight% of the addition amount shows the weight% per absolute dry pulp. Example 1. Beat wood pulp (LBKP 100%),
A pulp slurry with a Canadian freeness of 250 ml was obtained. Then, about 3.5% by weight of this pulp slurry
Adjusted to a concentration of 0.25% by weight of cationized starch having a nitrogen content of 0.25% by weight (Ace K-100: trade name of Oji Cornstarch Co., Ltd.), 1.3% by weight, alkyl ketene dimer, 0.5% by weight, epoxy Behenamide amide 0.1% by weight, polyamide polyamine epichlorohydrin 0.3% by weight, polyacrylamide diallylamine salt 0.1% by weight are added and stirred to adjust the pH of the pulp slurry to 8.0 sodium hydroxide. Was added.

Next, 0.03% by weight of a defoaming agent was added, and sodium salt of carboxymethyl cellulose was added so that the final zeda potential of the pulp slurry was in the range of -15 mv to 0 mv, and the pulp slurry concentration was about 1. After adjusting to 0% by weight, anionic colloidal silica (BMA-
0: 0.15% by weight of Nissan Eka Nobel Co., Ltd.) was added. After gently stirring, the paper was further dehydrated and dried, and the basis weight of the base paper was adjusted to 162 g / m ² . A solution having the composition shown in Table 1 below was size-pressed on both sides of the base paper produced as described above, and the amount of adhesion when applied was 35 g / m 2.
^The liquid was attached so as to be ² .

[0045]

[Table 1] ──────────────────────── Polyvinyl alcohol: 5.0% by weight Calcium chloride: 3.0% by weight Optical brightener: 0 .4 wt% defoamer: 0.005 wt% water: 91.595 wt% ─────────────────────────

The thickness of the obtained size liquid-adhered paper was adjusted to 158 μm using a machine calender, and then 13 on the back surface.
Corona discharge treatment with KVA, then density 0.980
About 30 μm of polyethylene of g / m ² was coated. Furthermore, after subjecting the front surface (the side coated with the photographic emulsion) to a corona discharge treatment at 13 KVA, about 3% polyethylene having a density of 0.960 g / m ² containing 10% by weight of titanium oxide is used.
The support was coated with 0 μm to obtain a support for photographic printing paper.

Example 2. A support for photographic printing paper was obtained in exactly the same manner as in Example 1 except that the corona discharge treatment was carried out at 17 KVA on both the back surface and the front surface. Example 3. As a size solution, a solution having the composition shown in Table 2 below was used, and these were adhered to the front surface of the base paper so as to be 30 g / m ² , and both the back surface and the front surface were subjected to corona discharge treatment at 16 KVA. To obtain a support for photographic printing paper.

[0048]

[Table 2] ──────────────────────── Polyvinyl alcohol: 4.0% by weight Calcium chloride: 3.5% by weight Optical brightener: 0 .45% by weight Defoaming agent: 0.004% by weight Water: 92.046% by weight ─────────────────────────

Example 4. Example 1 was repeated except that a solution having the composition shown in Table 3 below was used as a size solution and these were adhered to the surface of the base paper so as to have a rate of 30 g / m ^2, and both the back surface and the front surface were subjected to corona discharge treatment at 15 KVA. A support for photographic printing paper was obtained in exactly the same manner as.

[Table 3] ──────────────────────── Oxidized starch: 14.0% by weight Calcium chloride: 4.0% by weight Optical brightener: 0 0.5 wt% defoamer: 0.014 wt% water: 81.486 wt% ─────────────────────────

Example 5. Mixture of wood pulp (LBKP
/ LBSP = 50/50) was beaten to obtain a pulp slurry having a Canadian freeness of 300 ml. Then
Adjust the pulp slurry to a concentration of about 3.5% by weight,
Cationized starch having a nitrogen content of 0.25% by weight (Ace K-100: trade name of Oji Corn Starch Co., Ltd.)
20% by weight, alkyl ketene dimer 0.75% by weight,
Polyamide polyamine epichlorohydrin 0.3% by weight
Was added and stirred, and sodium hydroxide was added so that the pH of the pulp slurry would be 7.0.

Next, 0.03% by weight of a defoaming agent was added, and a carboxy-modified polyvinyl alcohol aqueous solution was added so that the final zeta potential of the pulp slurry was in the range of -15 mv to 0 mv. Pulp slurry concentration about 1.0
After adjusting to weight%, bentonite (Hydrocor WJ:
0.20% by weight of Allied Colloid Co., Ltd.) was added. After gentle stirring, dehydration and drying,
The operation was performed so that the basis weight of the base paper was 168 g / m ² . A support for photographic printing paper was obtained in exactly the same manner as in Example 1 except that the base paper thus obtained was used and the backside and frontside corona discharge treatments were carried out at 14 KVA.

Example 6. A solution having the composition shown in Table 4 below was used as the size solution, and the amount of the solution attached to the surface of the base paper was 30 g / m
^A support for photographic printing paper was obtained in exactly the same manner as in Example 5 except that the back surface and the front surface were subjected to corona discharge treatment at 15 KVA while being adhered so as to be ² .

[Table 4] ──────────────────────── Oxidized starch: 7.0% by weight Calcium chloride: 2.5% by weight Optical brightener: 0 0.5 wt% defoamer: 0.0095 wt% water: 89.99905 wt% ─────────────────────────

Example 7. Adjust the pH of the pulp slurry to 6.5
A photographic printing paper support was obtained in exactly the same manner as in Example 1 except that the above-mentioned adjustment was made. Example 8. A support for photographic printing paper was obtained in exactly the same manner as in Example 1 except that the pH of the pulp slurry was adjusted to 9.0.

Example 9. The chaotic starch was changed to Cato 302 (the former Oji National Co., Ltd. trade name of chaotic starch) having a nitrogen content of 0.13% by weight.
A support for photographic printing paper was obtained in exactly the same manner as in Example 1. Example 10. Chaotinated starch with a nitrogen content of 0.38
A support for photographic printing paper was obtained in exactly the same manner as in Example 1 except that the weight percent of potato starch was changed.

Comparative Example 1. A photographic printing paper support was obtained in the same manner as in Example 1 except that no corona discharge treatment was performed. Comparative example 2. Corona discharge treatment for the back and front
A support for photographic printing paper was obtained in exactly the same manner as in Example 1 except that both were performed at 8 KVA.

Comparative Example 3. Adhesion amount of size liquid is 10g / m
² and the back and front corona discharge treatment is 10
A support for photographic printing paper was obtained in exactly the same manner as in Example 1 except that KVA was used. Comparative Example 4. Polyacrylamide diallylamine salt
A support for photographic printing paper was obtained in exactly the same manner as in Example 1 except that 1% by weight was not added and the pH of the pulp slurry was adjusted to 4.0 by adding sulfuric acid.

Comparative Example 5. Example except that 0.1% by weight of polyacrylamide diallylamine salt was not added, 0.5% by weight of aluminum sulfate was added, and sodium hydroxide was added so that the pH of the pulp slurry was 7.0. A support for photographic printing paper was obtained in exactly the same manner as in 1.

Comparative Example 6. The pH of the pulp slurry is 10.
A support for photographic printing paper was obtained in exactly the same manner as in Example 1 except that sodium hydroxide was added so as to give 0. The photographic printing paper support 1 obtained in each of the examples and comparative examples was cut into a piece having a width of 1.5 cm, and as shown in FIG.
The results of measuring the 80 ° adhesive force using Tensilon RTM-25 (trade name of Orientec Co., Ltd.) are shown in Table 5.
As shown in.

[Table 5] From the results of Table 5, it was demonstrated that the adhesive force of the photographic printing paper support of the present invention was 320 g or more.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a method for measuring an adhesive force of a laminating film in a support for photographic printing paper according to the present invention.

[Explanation of symbols]

 1 Support for photographic printing paper 2 Resin coating layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location D21H 17/05 17/28 G03C 1/91 // B32B 27/10 8413-4F

Claims (4)

[Claims] 1. A support for photographic printing paper, comprising a base paper coated on both sides with a polyolefin resin, wherein the base paper has a nitrogen content of 0.1% by weight or more of chaotic starch and an alkyl ketene dimer. And / or an epoxidized higher fatty acid amide, having a cold water extraction pH of 6.0 to 7.5, and having an adhesive force of 320 g or more between the base paper and the polyolefin resin film. Support for photographic paper. 2. The water absorption of the base paper by the Cobb method is 30 g /
The support for photographic printing paper according to claim 1, wherein the support is m ² or less. 3. A chaotinated starch having a nitrogen content of 0.1% by weight or more, and an alkyl ketene dimer and / or an epoxidized higher fatty acid amide and having a pH of 6.0 to 9.
For at least one side of the base paper made from 0 stock
2. The surface treatment is performed so that the surface O / C (oxygen / carbon count number ratio) value by ESCA is 1.0 or more, and then both surfaces of the base paper are coated with a polyolefin resin. For producing the photographic paper support described above. 4. A solution containing polyvinyl alcohol and / or starch as a main component is previously applied and dried on the surface of the base paper which is surface-treated so that the O / C value becomes 1.0 or more. Item 4. A method for producing a support for photographic printing paper according to item 3.