JPH03184040A - Base for photographic printing paper - Google Patents

Abstract

PURPOSE:To lower the absorptivity of a processing liquid by subjecting raw paper to an internal addition sizing treatment by epoxidated behenic amide and to a surface sizing treatment by a reducing agent consisting of the aldehyde addition product of an inorg. salt and/or inorg. salt. CONSTITUTION:The raw paper is subjected to the internal addition sizing treatment by the epoxidated behenic amide and is then subjected to the surface sizing treatment by the reducing agent consisting of the aldehyde addition product of the inorg. salt and/or inorg. salt. An aldehyde scavenger is preferably used in combination when the aldehyde addition product of the inorg. salt is used as the reducing agent. Ethylene urea is preferebly added into the paper when for example, the formaldehyde addition product is used. The absorption of a developing liquid is suppressed and the coloration over the entire part of the printing paper is prevented with the raw paper internally added with the epoxidated behenic amide in such a manner.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a support for photographic paper, and particularly to a support for photographic paper that can improve edge stains of photographic paper.

(Prior Art) Since photographic paper is required to absorb as little processing liquid as possible during development processing, attempts have been made to reduce the absorbency of processing liquid in paper as a support. One of the methods is to reduce the absorbency of the processing liquid by sizing the paper, and it is well known that conventional baryta paper has been dealt with only by this method. However, this method was still insufficient to reduce the absorbency of the treatment liquid.

Another method for reducing the treatment liquid absorption of the support is to coat the front and back surfaces of the base paper with a water-resistant film such as polyolefin. Although this method allows the processing liquid to penetrate into the base paper only from the cut surfaces at the edges, it is not possible to completely prevent the processing liquid from penetrating from the cut surfaces, and the processing liquid that could not be removed by washing with water is It changes color with heat and over time, resulting in so-called edge stains. This edge stain becomes brown stain-like stains on the white edges of the photo and significantly reduces the value of the photo.

The above-mentioned edge stains will not occur if water washing is performed for a long time after development, but this goes against the requirement that the development process be done in a short time, and therefore reduces the absorption of processing liquid from the cut surface. was strongly desired.

(Problem to be Solved by the Invention) Therefore, it has been considered to apply a sizing agent to the base paper in order to reduce the absorbency of the processing liquid, and a sizing agent of fatty acid soap type such as sodium stearate (Japanese Patent Publication No. 47 -26961), alkyl ketene dimer (JP-A-51-132822), or cationic sizing agent obtained by reaction of carboxylic acid with polyvalent amine (JP-A-54-147032), etc. are used as supports for photographic paper. It is used as a body sizing agent. However, fatty acid soap-type sizing agents cannot lower the processing liquid absorbency any further than they currently do, and are affected by the quality of the water used to manufacture base paper, and if the water is hard, precipitation will occur. There was a drawback that a sufficient effect could not be obtained. On the other hand, the method using an alkyl ketene dimer has problems such as poor adhesion between the polyolefin or polystyrene film and the base paper, requiring a separate process to improve adhesion. Furthermore, when using a cationic sizing agent obtained by reacting a carboxylic acid with a polyvalent amine, although the absorbency of the processing liquid becomes low, coloring due to the slightly absorbed processing liquid cannot be avoided. , was not satisfactory.

As a result of intensive studies to improve the above-mentioned drawbacks, the inventors of the present invention coated both sides of base paper with polyolefin, which was produced by applying internal sizing treatment using a specific sizing agent and further performing specific surface sizing treatment. The present inventors have discovered that, in some cases, edge stains are significantly improved, resulting in a photographic paper suitable for rapid processing.

Therefore, a first object of the present invention is to provide a support for photographic paper that has low processing liquid absorption.

A second object of the present invention is to provide a support for photographic paper that exhibits excellent adhesion between a base paper and a film made of polyolefin or the like when coated with a water-resistant film made of polyolefin or the like.

A third object of the present invention is to provide a support for photographic paper that does not cause any damage to photographic properties such as fogging.

<Means for Solving the Problems> The above aspects of the present invention provide a support for photographic paper in which both sides of a base paper are coated with polyolefin, the base paper comprising:
This is achieved by a support for photographic paper, which is a base paper that has been internally sized with epoxidized behenic acid amide and surface sized with a reducing agent consisting of an inorganic salt and/or an aldehyde adduct of the inorganic salt. It was done.

The material of the base paper used in the present invention is not particularly limited, and the main raw material may be natural pulp selected from conifers, hardwoods, etc., or the natural pulp and bottom valve may be mixed in any ratio as necessary. A mixture can also be used.

The epoxidized behenic acid amide internally added to the base paper in the present invention is a compound represented by the formula -, and can be easily obtained by reacting behenic acid and polyalkylene polyamine as main components by a known method. In the above formula, n is 2 to 1
0, particularly preferably 2 to 6, and m is 1 to
It is 3. Among these compounds, especially those with a molecular weight of 700
The above are preferred, and the amount added is 0.1 to 2.0% by weight, preferably 0.3 to 1.0% by weight, based on the entire base paper. Further, when the above-mentioned compound is internally added to the base paper, no special operation is required, and the necessary amount can be simply added to the pulp water.

As described above, the base paper to which epoxidized behenic acid amide is added is suppressed from absorbing the developer, thereby preventing the entire photographic paper from being colored.

If necessary, commonly used additive chemicals may be further added to the base paper. Such additive chemicals include fillers such as clay, talc, calcium carbonate, and urea resins, sizing agents such as rosin, alkyl ketene dimer, higher fatty acid salts, paraffin wax, and alkenyl succinic acid, and fixing agents such as sulfuric acid and aluminum chloride. agent, dye, fluorescent dye, slime control agent, antifoaming agent, etc.

Further, when an aldehyde adduct of an inorganic salt is used as a reducing agent, it is preferable to use an aldehyde scavenger together. For example, when using a formaldehyde adduct, it is desirable to add ethylene urea to the paper.

In the present invention, after paper is made from pulp water containing at least the epoxidized behenic acid amide, surface sizing treatment is performed using a reducing agent consisting of an inorganic salt and/or an aldehyde adduct of the inorganic salt.

Examples of inorganic salts that can be used here include sulfites (sodium sulfite, acidic sodium sulfite, calcium sulfite, potassium sulfite, acidic potassium sulfite, barium sulfite, zinc sulfite, manganese sulfite, magnesium sulfite, lead sulfite, cobalt sulfite). , strontium sulfite, etc.), bisulfites (e.g. sodium bisulfite, calcium bisulfite, potassium bisulfite,
Barium hydrogen sulfite, zinc hydrogen sulfite, manganese hydrogen sulfite, magnesium hydrogen sulfite, lead hydrogen sulfite, cobalt hydrogen sulfite, strontium hydrogen sulfite, etc.), dithionite (sodium dithionite, zinc dithionite, etc.), boron hydride Refers to sodium, hydroxymethane sulfonate (ammonium salt of alkaline earth metal, alkali metal salt such as formaldehyde sodium sulfoxylate, etc.), and sulfite and bisulfite are particularly effective. However, the present invention is not limited to the above reducing agents.

These inorganic salts can be used alone or in combination of two or more.

In addition, the aldehyde adduct of inorganic salt used in the present invention is
It is a compound obtained by reacting various aldehydes with the above inorganic salts, and specific examples thereof include formaldehyde bisulfite, acetaldehyde bisulfite, propionaldehyde bisulfite, benzaldehyde bisulfite, etc. .

In the present invention, aldehyde bisulfites having 1 to 10 carbon atoms are particularly preferred, and formaldehyde bisulfites are most preferred. Examples of metals that form salts include sodium, potassium, calcium, barium, manganese, magnesium, cobalt, and strontium, and among these, sodium is particularly preferred.

At least one reducing agent consisting of the above-mentioned inorganic salt and/or aldehyde adduct of the inorganic salt is added to the photographic paper support.
．． Range of 1g/rrf to 10g/bo, preferably 0.3
It can be contained in a range of g/rrf to 5 g/rrf.

The above reducing agents can be used as aqueous solutions or can be used in film-forming polymers commonly used as surface sizing agents, such as gelatin, starch, carboxymethyl cellulose, polyacrylic straw, polyvinyl alcohol, and modified products of polyvinyl alcohol. It may also be used after being dispersed in an aqueous solution.

By using a reducing agent made of an inorganic salt and/or an aldehyde adduct of an inorganic salt as a surface sizing agent as described above, it is possible to prevent coloring of the developer that has soaked into the developer.

The above-mentioned surface sizing treatment is performed either after pulp water is made into paper using a paper machine such as a fourdrinier machine, or after paper is made and dried.

After final drying, the base paper is calendered and rolled up for production.

The photographic paper support of the present invention can be obtained by extrusion coating both sides of the base paper produced as described above with a polyolefin resin in a known manner.

As equipment for extrusion coating, a conventional polyolefin extruder and laminator are used.

Examples of the polyolefin resin include homopolymers of α-olefins such as polyethylene and polypropylene, and mixtures of these various polymers. Particularly preferred polyolefins are high density polyethylene, low density polyethylene and mixtures thereof. There is no particular restriction on the molecular weight of these polyolefins as long as they can be extrusion coated, but polyolefins having a molecular weight in the range of 20.000 to 200.000 are usually used.

The thickness of the polyolefin resin coating layer is not particularly limited and can be determined according to the thickness of the polyolefin resin coating layer for conventional photographic paper supports, but is usually 15 to 5.
0 μm is suitable.

Known additives such as white pigments, colored pigments, fluorescent whitening agents, and antioxidants can be added to the polyolefin resin layer. In particular, it is preferable to add a white pigment and a colored pigment to the polyolefin resin coating layer on the front surface to which the photographic emulsion is applied.

The photographic paper support of the present invention is further coated with a photographic emulsion layer on one side and dried to obtain a photographic paper, and on the other side is a print preservation layer as disclosed in, for example, JP-A-62-6256. Various types of tq are possible, such as the possibility of providing tq.

(Effects of the Invention) As detailed above, in the photographic paper support of the present invention, not only the base paper itself has low liquid absorption, but also the coloring caused by the permeated developer is suppressed by the reducing agent attached as a surface sizing agent. Therefore, edge stains can be significantly improved without washing thoroughly with water, and therefore, it is suitable as a support for so-called rapid processing photographic paper.

(Examples) Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto.

Example 1 A mixed pulp of 70 parts of LBKP and 30 parts of LBSP was beaten to a Canadian freeness of 300-, the following chemicals were added to this pulp slurry, and paper was made and dried to give a basis weight of 180 g.
/rrf base paper was obtained.

Pulp: 100 parts by weight Epoxidized behenic acid amide: 0.6 parts by weight (compound with n-2, m=2 in the general formula described in the specification) Anionic polyacrylamide: 1.0 parts by weight Aluminum sulfate: 1.5 Part by weight Caustic soda
: Adjusted to pH 7.0 Polyamideborium-based epichlorohydrin 0.5 parts by weight Cationic polyacrylamide: 0.5 parts by weight Antifoaming agent: 0.1 parts by weight The following composition was added to the base paper obtained as above. An aqueous solution of 30 g/rrf was impregnated and deposited by size press treatment.

Polyvinyl alcohol: 5. (H! 1 part Formaldehyde Sodium bisulfite: 2.0 parts by weight Fluorescent brightener: 0.5 parts by weight Ethylene urea = 1.0 parts by weight Next, the obtained paper coated with the size liquid was machine calendered to a thickness of 175 μm.
After adjusting the density to m and then corona discharge treatment on the back side, the density is 0.
．． 98 g/cd polyethylene is coated with a thickness of 25 μm, and the front side (the side coated with photographic emulsion) is coated with a density of 0.9 containing 10% by weight of titanium oxide after corona discharge treatment.
A photographic support (2) was obtained by coating 30 μm of 4 g/d polyethylene.

8.25C1 m of the photographic support obtained as described above
Cut into width and use Fuji Color Paper Processing Chemical CP-20A
(P-1 color developer) was automatically developed at 36°C for 8 minutes, washed with water at 20"C for 2 minutes, and then heat-treated at 60°C and 90% relative humidity for 15 hours. When the permeability and colorability were evaluated by evaluating edge staining upon heat treatment, no staining was observed and the results were very good.

Example 2゜Example 1 except that the amount of epoxidized behenic acid amide added internally in Example 1 was 0.8 parts by weight, and the amount of sodium formaldehyde bisulfite in the surface sizing liquid was changed to 1.0 parts by weight.
A photographic support was obtained in exactly the same manner as (Photographic support ■
), the obtained photographic support (2) was evaluated for edge staining in exactly the same manner as in Example 1, and no staining was observed, giving very good results.

Example 3゜Example 1 except that the amount of epoxidized behenic acid adduct internally added in Example 1 was 0.4 parts by weight, and the amount of sodium formaldehyde bisulfite in the surface sizing liquid was changed to 3.0 parts by weight.
A photographic support was obtained in exactly the same manner as (Photographic support ■
), the obtained photographic support (2) was evaluated for edge staining in exactly the same manner as in Example 1, and no staining was observed, giving very good results.

Comparative Example 1. Photographic support (2) was obtained in exactly the same manner as in Example 3, except that sodium formaldehyde bisulfite in the surface sizing solution used in Example 3 was removed.

When the obtained photographic support (3) was evaluated for edge staining in the same manner as in Example 1, the edges were colored brown and the commercial value as a photographic paper was low.

Comparative Example 2 Photographic support (2) was obtained in exactly the same manner as in Example 1, except that epoxidized stearic acid amide was used instead of the epoxidized behenic acid amide added internally in Example 1. When the obtained photographic support (3) was evaluated for edge staining in the same manner as in Example 1, the edges were colored yellow and the commercial value as a photographic paper was low.

Comparative Example 3 A photographic support was prepared in the same manner as in Example 1, except that an alkyl ketene dimer (stearic acid/valmitic acid = 7/3) was used instead of the epoxidized behenic acid amide added internally in Example 1. I got ■. The obtained photographic support (2) was evaluated for edge staining in the same manner as in Example 1.
The edges were colored yellow, and the commercial value of the paper as a photographic paper was low.

The results of the above Examples and Comparative Examples demonstrate that the photographic support according to the present invention is a support for photographic paper having excellent properties without edge stains.

Claims (1)

[Scope of Claims] 1) A support for photographic paper in which both sides of a base paper are coated with polyolefin, wherein the base paper is internally sized with epoxidized behenic acid amide and treated with an inorganic salt and/or an aldehyde of an inorganic salt. A support for photographic paper, characterized in that it is a base paper whose surface has been subjected to sizing treatment with a reducing agent consisting of an adduct. 2) The photographic print according to claim 1, wherein the epoxidized behenic acid amide is a behenic acid amide represented by the general formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (n is 2 to 10, m is 1 to 3) Support for paper.