JPH0854708A - Production of substrate for photographic printing paper - Google Patents

Abstract

PURPOSE:To produce a substrate excellent in surface smoothness and slightly permeable to a developing soln. at the time of development. CONSTITUTION:Both sides of base paper made from paper stock contg. at least cationic starch, polyamide polyamine epichlorohydrin and a copolymer of an acrylamide compd. with a dialkylamine salt are coated with a resin having film forming ability to produce the objective substrate for photographic printing paper. At the time of making the base paper, the paper stock is adjusted to -10 to +5mV zeta-potential and pH 6.5-8.5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a photographic printing paper support, and particularly to a photographic printing paper which has a low permeability of a processing solution at the time of development and an excellent surface smoothness. It relates to a method of manufacturing a support.

[0002]

2. Description of the Related Art In recent years, both sides of a base paper have been used as a support for photographic printing paper in order to prevent permeation of a processing solution in the development and fixing processing of photographs and to shorten the time spent for washing and drying. A water-resistant photographic printing paper support coated with a polyolefin such as polyethylene is preferably used.

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

By the way, the base paper for the support for photographic paper needs to be a strong size paper in order to prevent the permeation of the developing solution from the cut surface of the support during the development processing. Therefore, when a neutral paper is used as a base paper for a support for photographic paper, a self-fixing alkyl ketene dimer is used as a sizing agent, and a cationic polyacrylamide must be used as a paper strength agent. There wasn't.

In this case, papermaking in the neutral range (paper material pH = 6.0 or more and 8.5 or less) is performed in the acidic area (paper material pH = 3.
(5 or more and less than 6.0), the water drainage on the wire may be inferior and the drying load may increase compared to papermaking with a roll size such as an alkyl ketene dimer as a sizing agent. It has a drawback that it is generated or the surface of the base paper that is made paper is slippery.

These drawbacks are ameliorated by using a cationic polyacrylamide having a specific molecular weight and a specific cation value, which is obtained by copolymerization of acrylamide and a cationic monomer (JP-A-4-1-1).
No. 31843). It has also been found that it is preferable to use anionic polyacrylamide together with the epoxidized higher fatty acid amide in the above system (JP-A-4-131843).

[0007] As for the surface of photographs, those having higher smoothness tend to be preferred. Therefore, the present inventors
As a result of diligent studies on a base paper that can improve the smoothness of the photographic paper with high strength, at least, cation-starch, polyamide polyamine epichlorohydrin, and, together with containing a copolymer of an acrylamide compound and a diallylamine salt, It has been found that an extremely good support for photographic printing paper can be obtained when the pH and zeta potential of the stock material during papermaking are adjusted to specific ranges, and the present invention was reached.

[0008]

SUMMARY OF THE INVENTION It is, therefore, a first object of the present invention to provide a method for producing a support for photographic printing paper, which has a low penetration of a processing solution during development. It is a second object of the present invention to provide a method for producing a photographic paper support having extremely good surface smoothness.

[0009]

Means for Solving the Problems The above-mentioned various objects of the present invention are based on a base paper made from a stock containing at least a cationic starch, a polyamide polyamine epichlorohydrin, and a copolymer of an acrylamide compound and a diallylamine salt. A method for producing a support for photographic printing paper, which comprises coating both sides with a resin capable of forming a film, wherein the zeta potential of the stock is -10 to +5 m when making the base paper.
It was achieved by a method for producing a photographic paper support characterized by adjusting V and pH in the range of 6.5 to 8.5.

The resin capable of forming a film in the present invention includes polyolefin resins such as polyethylene and polypropylene, as well as polybutene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polyethylene terephthalate, polyamide and polyacrylic acid ester. Among these, polyethylene is particularly preferably used from the viewpoints of suitability for melt extrusion when coating the base paper, adhesiveness with the base paper, and the like.

The molecular weight of these resin capable of forming a film is not particularly limited as long as it is possible to add a white pigment, a coloring pigment or a fluorescent brightening agent to the coating layer formed by extrusion coating. Usually 20,000
Those in the range of up to 200,000 are used. The thickness of the resin coating layer is not particularly limited, and can be determined according to the conventional thickness of the resin layer of the photographic paper support,
Generally, its thickness is 15-50 μm.

Addition of stabilizers such as white pigments, coloring pigments or fluorescent whitening agents, phenols, bisphenols, thiobisphenols, amines, benzophenones, salicylates, benzotriazoles and organometallic compounds to the resin coating layer. You can In particular, it is preferable to add a white pigment and a coloring pigment to the resin coating layer on the side on which the photographic emulsion is coated. As the extrusion coating equipment for extrusion coating the resin, an ordinary polyolefin extruder and a laminator are used.

Next, the base paper used in the present invention will be described in detail. In the base paper used in the present invention, natural pulp or synthetic pulp can be used alone or in an appropriate combination, and in particular, from the viewpoint of improving the smoothness, 35 to 70% by weight of the pulp used. Is preferably LBSP, and particularly preferably 40 to 60% by weight is LBSP.

The freeness of the pulp used is preferably 200 to 300 milliliters (C.S.F.) as total pulp, and more preferably 200 to 260 milliliters. The freeness of LBSP alone is 22.
It is preferably 0 to 260 ml.

In the present invention, cationic starch is added as a dry paper strengthening agent. Examples of the cation starch include starch made from corn, tapioca, potato, etc., which has been modified with a tertiary or quaternary cation. The degree of substitution for cation modification is preferably 0.02 to 0.06. Further, the addition amount thereof is preferably 0.5 to 5.0% by weight with respect to the pulp, and particularly 1
It is preferably ˜3% by weight.

In the present invention, a polyamide polyamine epichlorohydrin represented by the following chemical formula 1 is further added as a wet paper strengthening agent.

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The above-mentioned polyamide polyamine epichlorohydrin is a basic low molecular weight compound derived from an aliphatic dicarboxylic acid (eg adipic acid, succinic acid) and a polyalkylene polyamine (eg diethylene triamine, tetraethylene pentamine). It can be easily obtained by reacting a polyamide with epichlorohydrin. The amount of the polyamide polyamine epichlorohydrin added is preferably in the range of 0.05 to 3.0% by weight, particularly 0.2 to 1.0% by weight, based on the pulp.
It is preferably in the range of.

In the present invention, a copolymer of an acrylamide compound and a diallylamine salt is further added from the viewpoint of preventing permeation of the processing solution during development. As the acrylamide compound in the copolymer of the acrylamide compound and the diallylamine salt, acrylamide or methylmethacrylamide is used, and as the diallylamine salt, inorganic acid salts such as hydrochloric acid, sulfuric acid, phosphoric acid of diallylamine or formic acid, acetic acid, propionic acid. An organic acid salt such as is used.

The molar ratio of the acrylamide compound to the diallylamine salt is preferably in the range of 1/1 to 10/1. In addition to the above two components, other vinyl monomer such as acrylonitrile, vinyl acetate, acrylic acid, dimethylaminoethyl acrylate, etc. can be copolymerized as the third component, if necessary.

These copolymers preferably have an average molecular weight of 50,000 to 1,000,000 as measured by the GPC method (gel permeation chromatography), and particularly 10
It is preferably from 10,000 to 500,000. The amount of these copolymers added is preferably in the range of 0.01 to 2.0% by weight, particularly 0.05 to 0.5% by weight, based on the pulp.
It is preferably in the range of.

Further, in the present invention, it is preferable to add polyacrylamide together with the cationic starch. Examples of the polyacrylamide include anionic polyacrylamide, cationic polyacrylamide, and amphoteric polyacrylamide, and it is particularly preferable to use amphoteric polyacrylamide in combination.

The above-mentioned amphoteric polyacrylamide is an amphoteric copolymer obtained by copolymerizing an anion monomer and a cation monomer while using acrylamide or methacrylamide as a main monomer component, and is a GPC method (gel permeation chromatography). The average molecular weight measured by 2) is preferably 2,000,000 to 5,000,000,
It is particularly preferably 2,000,000 to 3.5,000,000. The amount of the amphoteric polyacrylamide used is 0.
It is preferably in the range of 01 to 5.0% by weight, and particularly preferably in the range of 0.1 to 1.0% by weight.

In the present invention, epoxidized higher fatty acid amide and / or
Alternatively, it is preferable to use an alkyl ketene dimer. Specific examples of the epoxidized higher fatty acid amide used in the present invention include, for example, JP-B-38-20601 and JP-A-38-20601.
Nos. 9-4507 and U.S. Pat. No. 3,692,092, obtained by condensation of fatty acids with polyamines, alkenyl succinic acids as described in JP-A-51-1705. Examples thereof include those obtained by reacting an acid with a polyvalent amine.

In the present invention, among the above fatty acids, higher 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 an aliphatic carboxylic acid include, for example, stearic acid, oleic acid, lauric acid, palmitic acid, arachidic acid, behenic acid, tall oil fatty acid,
Examples thereof include alkyl succinic acid and alkenyl succinic acid, and among these, behenic acid is particularly preferable.
Two or more kinds of fatty acids may be used in combination.

As the polyvalent amine, polyalkylene polyamine is preferable, and among them, those having 2 to 3 methylene groups between amino groups are preferable. Specific examples include diethylenetriamine, triethylenetetramine,
Examples include tetraethylenepentamine, pentaethylenehexamine, dipropylenetriamine, tripropylenetetramine, aminoethylethanolamine and the like.

In the present invention, it is preferable to use a reaction product of an aliphatic carboxylic acid and a polyvalent amine as a quaternary salt with epichlorohydrin so that the sizing agent does not fall off from the pulp by mechanical stirring. . The amount of the epoxidized higher aliphatic amide used in the present invention is preferably 0.1 to 3.0% by weight, and particularly preferably 0.3 to 1.5% by weight, based on the pulp.

The alkyl ketene dimer used in the present invention is preferably one produced by using a higher fatty acid having 8 to 30 carbon atoms, and particularly preferably an alkyl ketene dimer produced by using behenic acid. The amount added is preferably 0.1 to 3.0% by weight, and particularly preferably 0.3 to 1.5% by weight, based on the pulp.

In the present invention, in the pulp slurry,
A polyvalent metal salt may be further added as a fixing agent. As such a polyvalent metal salt, water-soluble aluminum salts such as aluminum sulfate and aluminum chloride are particularly preferable. These fixing agents are preferably added to the paper material in an amount of 0.1 to 1.0% by weight. When the pH of the pulp slurry becomes acidic due to the addition of these polyvalent metal salts, an alkaline substance such as sodium hydroxide or sodium aluminate is added to adjust the pH to 6.5 to 8.5. It is preferable to control to the range of nature in order to improve the storability of the base paper and thus the storability of the photographic paper support.

In the present invention, the zeta potential of the pulp slurry thus obtained is preferably in the range of -10 to +5 mV, and particularly preferably in the range of -5 to +1 mV. If the zeta potential is less than -10 mV or exceeds +5 mV, the depth of penetration of the developing solution from the cut end face of the photographic paper at the time of development becomes large, and a photographic photographic paper that can be used cannot be obtained.

The zeta potential of the pulp slurry can be adjusted by adding an anionic substance to 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.

Examples of the zeta-potential adjusting agent include carboxymethyl cellulose salt, carboxy modified polyvinyl alcohol, sodium polyacrylate and the like. Among these, carboxymethyl cellulose salt is particularly preferable. The above-mentioned carboxymethyl cellulose salt is a salt in which a carboxymethyl group is ether-bonded to a hydroxyl group of cellulose, and a sodium salt is particularly preferably used in the present invention.

The etherification degree of the above carboxymethyl cellulose salt is preferably 0.5 to 0.8,
The average degree of polymerization is preferably 300 to 500. The amount of carboxymethyl cellulose salt added is preferably in the range of 0.01 to 1.0% by weight, and particularly preferably in the range of 0.05 to 0.5% by weight, based on the pulp. Further, as the zeta potential adjusting agent, 2
It is also possible to use two or more compounds in combination.

In the present invention, if necessary, a filler such as clay, talc, kaolin, calcium carbonate, titanium oxide or urea resin fine particles; rosin, higher fatty acid salt, paraffin wax, alkenyl succinic anhydride,
Sizing agent such as styrene-acrylic acid copolymer; paper strength agent such as gelatin; wet paper strength agent such as melamine formalin condensate;
Other dyes, optical brighteners, defoamers, etc. may be added.

As a method of adding each chemical to the paper stock, it is preferable to add cation starch, an alkaline substance, and a copolymer of an acrylamide compound and a diallylamine salt in this order. The alkaline material has a final pH of the stock of 6.5 to
Add while adjusting to 8.5. pH is 6.
When it is less than 5, the penetration depth during development is increased, and when the pH is 8.5 or more, the dewatering property of the wire during papermaking is significantly deteriorated, which is not preferable. The epoxidized higher fatty acid amide and the alkyl ketene dimer show good sizing properties in any order of addition, but it is particularly preferable to add them after the addition of the cationic starch in terms of good dispersibility and sizing properties.

On the surface of the base paper obtained as described above,
A liquid containing various water-soluble additives may be impregnated and applied by a size press, a tab size or a gate roll coater. Examples of such water-soluble additives include starch, polyvinyl alcohol, carboxy-modified polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose, sodium alginate, cellulose sulfate, gelatin, polymer compounds such as casein, calcium chloride, sodium chloride, sodium sulfate. There are metal salts such as.

In the liquid containing the above water-soluble additive, hygroscopic substances such as glycerin and polyethylene glycol; coloring / whitening substances such as dyes and fluorescent whitening agents; caustic soda, ammonium water, hydrochloric acid, sulfuric acid, A pH control agent such as sodium carbonate may be added. In addition, a pigment or the like can be added to the aqueous solution, if necessary.

[0037] The thickness of the base paper is not particularly limited, basis ^{weight, 50g / m 2 ~250g / m} 2 is desirable. Also, from the viewpoint of the flatness of photographic printing paper, it is desirable to use a base paper that has excellent surface smoothness and flatness. Therefore, heat and pressure are applied to the surface of the base paper using a machine calendar, super calendar, or soft calendar. Preferably. The support for photographic printing paper of the present invention is coated with a photographic emulsion layer on its glossy surface and dried to give a photographic printing paper. On the other side, for example, a print preservation layer disclosed in JP-A-62-6256. Can be provided in various ways.

[0038]

According to the production method of the present invention, a support for photographic printing paper having not only good surface smoothness but also extremely low penetration of the developer from the end of the cut surface, Can be easily obtained.

[0039]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. Example 1. A wood pulp having an LBKP / LBSP weight ratio of 60/40 was beaten to obtain a pulp slurry having a Canadian freeness of 260 ml. While stirring the obtained pulp slurry, 1.5 parts by weight of katin starch, 0.2 parts by weight of epoxidized behenamide, 0.4 parts by weight of polyamide polyamine epichlorohydrin, and behenic acid as raw materials with respect to 100 parts by weight of pulp while stirring. 0.6 parts by weight of alkyl ketene dimer, 0.1 part by weight of copolymer (molecular weight 250,000) of acrylamide / diallylamine sulfate (molar ratio 70/30), and 0.15 part by weight of Na salt of carboxymethyl cellulose are added. It was Further, NaOH was added to adjust the pH of the stock to 8.0.

The zeta potential of the obtained pulp slurry was measured by a zeta potential measuring device MO manufactured by Penken.
It was -1 mV as measured by DEL501. Then 180 g / m ² from this pulp slurry
A size liquid having the composition shown in Table 1 below is size-pressed onto the surface of the base paper obtained by paper-making so that the adhesion amount of the liquid is 30 g /
It was attached so as to be m ² .

[0041]

[Table 1] ──────────────────────── Polyvinyl alcohol: 5.0% by weight Calcium chloride: 4.0% by weight Optical brightener: 0 0.5 wt% antifoaming agent: 0.005 wt% water: 90.495 wt% ─────────────────────────

The thickness of the obtained size liquid-adhered paper was adjusted to 173 μm using a machine calender, the back surface was subjected to corona discharge treatment, and then polyethylene having a density of 0.980 g / m ² was coated to about 30 μm. Furthermore, after the front surface (the side coated with the photographic emulsion) was subjected to corona discharge treatment, a density of 0.960 containing 10% by weight of titanium oxide was obtained.
A support for photographic printing paper was obtained by coating about 30 μm of polyethylene of g / m ² .

A color photographic paper obtained by coating a color emulsion on the obtained photographic paper support was developed using an automatic processor, and the processed photographic paper was permeated with the processing solution from the edges. When the depth was measured, the penetration depth was 0.34 mm
It was very small and extremely good. Further, when the smoothness of the screen of the photographic paper was visually judged, it was 5 out of a 5 step evaluation method, which was extremely good.

Examples 2-3 and Comparative Examples 1-4. A sample was obtained in the same manner as in Example 1 except that the chemical addition amount (parts by weight) shown in Table 2 below was used, and the penetration depth of each sample was measured.

[Table 2] The results are shown in Table 3 together with the results of Example 1.

[Table 3] The results of the above Examples and Comparative Examples demonstrate the effectiveness of the present invention.

Claims (1)

[Claims] 1. A photograph in which both sides of a base paper made from a paper stock containing at least a cationic starch, a polyamide polyamine epichlorohydrin, and a copolymer of an acrylamide compound and a diallylamine salt are coated with a resin capable of forming a film. A method for producing a support for photographic paper, comprising the step of making the zeta potential of a stock material −10 when making the base paper.
~ +5 mV, and adjusting the pH in the range of 6.5 to 8.5, a method for producing a support for photographic paper.