JPH05265131A - Substrate for photographic printing paper - Google Patents

Abstract

PURPOSE:To obtain a substrate for photographic printing paper which is excellent in water resistance, whiteness and surface smoothness, improves its curling tendency and is capable of recording sound information, etc. CONSTITUTION:One side of base paper is coated with a compsn. obtd. by mixing and dispersing a pigment in a synthetic resin and the other side is coated with a compsn. obtd. by mixing and dispersing ferro-magnetic powder in a synthetic resin.

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 which is less prone to curling over time and allows magnetic recording.

[0002]

2. Description of the Related Art Conventionally, in photographic printing paper, in order to improve water resistance and light reflection efficiency, the surface of the base paper on which the emulsion is coated is coated with a synthetic resin layer such as a polyolefin resin containing a pigment kneaded and dispersed therein. However, the back surface is coated with a synthetic resin such as a polyolefin resin. In this case, the pigment serves to improve the image quality by increasing the whiteness of the photographic paper, while degrading the flatness of the photographic paper surface.

[0003]

However, in a photographic printing paper having a glossy surface, which is most popularly used at present, in order to improve the appearance of the image, the flatness and glossiness of the surface of the printing paper are further improved. It is desired to improve. By the way, with the development of the information-oriented society, needs for photographs are diversified, and it is desired to be able to record other information other than the image information burned in the photographs, for example, surrounding voice at the time of taking a photograph. ..

The need for recording information other than the above-mentioned image information has been partially met by printing information (for example, the frame number of the photograph) on the back side of the photograph, but at the time of photographing. However, there is a drawback in that it is not possible to sufficiently meet the need for recording realistic audio information and the like around the.

The inventors of the present invention have made earnest studies to solve the above-mentioned drawbacks, and as a result, the surface of the base paper on which the emulsion is coated is coated with a composition prepared by mixing and dispersing a pigment in a synthetic resin, and the other surface is coated with the composition. By coating a resin with a composition in which ferromagnetic powder is mixed and dispersed, a new information recording medium that can not only improve curl (flatness) but also record voice information can be obtained. Find that you can
The present invention has been reached. Therefore, the object of the present invention is to provide water resistance,
Another object of the present invention is to provide a support for photographic printing paper, which has excellent whiteness and surface smoothness, and which can improve curl and record voice information.

[0006]

The above objects of the present invention are as follows.
A photographic print obtained by coating a composition in which a pigment is mixed and dispersed in a synthetic resin on one side of a base paper, and coating the composition in which a ferromagnetic powder is mixed and dispersed in a synthetic resin on the other side of the base paper. Achieved by paper support.

The pigment used in the present invention is not particularly limited as long as it can improve the whiteness of the surface of the photographic printing paper support when it is contained in a synthetic resin. Specific preferred examples of such a pigment include
Examples thereof include powders of titanium oxide, barium sulfate, zinc oxide, talc, calcium carbonate, aluminum oxide, silicon oxide and the like, or solid solutions thereof. Among these, titanium oxide and barium sulfate are particularly preferable, and titanium oxide is most preferable.

The average particle diameter of the pigment is preferably in the range of 0.04 to 1 μm. When it is 0.04 μm or less, it becomes difficult to uniformly mix and disperse the pigment in the resin layer, and
When it is 1 μm or more, the smoothness of the surface of the support for photographic printing paper cannot be obtained, and the whiteness becomes insufficient. In the case of titanium oxide and barium sulfate, the average particle size is 0.1 to 0.
The range of 8 μm is preferable.

The ferromagnetic powder used in the present invention is a ferromagnetic iron oxide such as a ferromagnetic alloy, maghemite and magnetite,
Examples thereof include known ferromagnetic powders for magnetic recording such as cobalt-modified iron oxide, barium ferrite, and chromium dioxide. From the viewpoint of improving the dispersibility, the surface of the particles of the ferromagnetic powder has a metal surface treating agent having a heterocyclic structure such as a coupling agent having silicon, titanium and aluminum as a central atom, and benzothiazole and benzotriazole. Alternatively, the surface treatment may be performed using a metal surface treatment agent having a functional group such as phosphoric acid, phosphonic acid, carboxylic acid and sulfonic acid.

The shape of the particles of the ferromagnetic powder is generally acicular particles, but plate-like particles, hexahedral particles, or the like may be used. The average particle size of the ferromagnetic powder is preferably 0.1 to 1 μm in the major axis in the case of needle-shaped particles and 0.1 to 0.8 μm in the case of plate-shaped particles. ..
When the particle diameter is less than the above range, it becomes difficult to uniformly mix and disperse the ferromagnetic powder in the resin layer, and when it exceeds the range, the back surface of the support (ferromagnetic layer side) The surface smoothness deteriorates, making it difficult to record and reproduce by magnetism. The content of the ferromagnetic powder in the composition is preferably 1 to 80% by weight. If it is 1% by weight or less, it becomes difficult to perform magnetic recording, and if it is 80% by weight or more, the durability of the ferromagnetic layer is deteriorated.

The synthetic resin containing a pigment or a ferromagnetic material used in the present invention is not particularly limited as long as it is a resin that can be extruded or dissolved by solvent.
Preferred synthetic resins include, for example, polyester resins such as polyethylene terephthalate, polyolefin resins such as polyethylene and polypropylene, polyamide resins such as nylon, styrene resins, vinyl alcohol resins,
Examples thereof include vinyl chloride resins such as polyvinyl chloride and vinyl acetate copolymers, acrylic resins such as acrylonitrile and polyacrylic acid esters, epoxy resins, and polyether ether ketone resins.

Among these resins, from the viewpoint of improving the dispersibility of the pigment or the ferromagnetic powder in the resin layer and enhancing the rigidity of the photographic printing paper support, the Heildbrand J.
Etch and Earl El Scott Solvency of Non-Electriitis 3rd Edition Reinhold Publisher, New York, 1953 (Hildebrand,
J, H., and RLSott, Solubility of Non-Electrolytes, 3
rd ed., Reinhold Publishing Corp., New york, 1953)
The solubility parameter δ ₂ described and defined in
It is preferable to use 0 or more resin as a main component.
In this case, the amount of the resin having δ ₂ of 10 or more is preferably 50% by weight or more in the composition.

As an example of δ ₂ of a typical resin, δ ₂
= 7.9 (polyethylene resin), δ ₂ = 8.6 (polystyrene resin), δ ₂ = 9.1 (poly (methylmethacrylate) resin), δ ₂ = 9.5 (polyvinyl chloride resin), δ
₂ = 10.7 (polyethylene terephthalate resin), δ
₂ = 13.6 (nylon 66) and δ ₂ = 15.4 (polyacrylonitrile), etc. [Fred W. Billmeyer, Jr. Textook o.
f Polymyer Science) description].

Among the resins having δ ₂ of 10 or more, the resin containing polyethylene terephthalate as a main component is preferable from the viewpoint of improving the flatness of the photographic printing paper support or the dispersibility of the ferromagnetic powder or pigment. In this case, the amount of the polyethylene terephthalate resin used is preferably 50% by weight or more in the resin composition from the viewpoint of keeping the surface smoothness and rigidity of the photographic printing paper support good.

Other resins (blend resins) that can be used in combination with the polyethylene terephthalate resin include polyolefin resins such as polyethylene and polypropylene, polyether resins such as polyethylene glycol, polyoxymethylene and polyoxypropylene, polyester-based polyurethanes and polyresins. It can be appropriately selected and used from a resin that can be extruded at 270 to 350 ° C. or a resin that can be melt-molded with a solvent, such as a urethane resin such as an ether polyurethane, a polycarbonate resin, and a polystyrene resin. Two or more kinds of the above blended resins may be used at the same time. Incidentally, the mixing of the synthetic resin such as polyethylene terephthalate and the titanium oxide or the ferromagnetic powder can be easily carried out by a conventional method.

In producing the support for photographic printing paper of the present invention, one side of a base paper is coated with a mixed composition of a synthetic resin and titanium oxide to form an emulsion-coated surface, and the other side. It can be manufactured by coating the surface of the with a mixed composition of a synthetic resin and a ferromagnetic powder. In this case, from the viewpoint of improving the magnetic recording characteristics of the support for photographic printing paper, by applying a magnetic field from the outside while the composition coating layer containing the ferromagnetic powder retains fluidity, It is preferable to orient the magnetic particles in the composition coating layer.

The thickness of the resin layer coated on the base paper is 5 to 5, respectively.
The range is preferably 50 μm, particularly 10 to 30
It is preferably in the range of μm. When the thickness is 50 μm or more, the coating layer is likely to be cracked, and the thickness is 5 μm.
The following is not preferable because the waterproofness of the support for photographic printing paper becomes insufficient and the rigidity decreases. Further, from the viewpoint of sufficiently preventing curl, it is preferable that the coating layers on both surfaces have substantially the same thickness.

When the base paper is coated with the above-mentioned mixed composition, the surface of the base paper may be pretreated by corona discharge treatment or undercoating. By coating a photographic emulsion layer on the titanium oxide-containing composition coating layer of the support obtained as described above in a known manner, not only water resistance but also whiteness and glossiness are excellent, and magnetic recording is possible. It is possible to obtain excellent photographic printing paper.

[0019]

The photographic printing paper support of the present invention comprises a base paper coated on one side with a composition in which a pigment is mixed and dispersed in a synthetic resin, and on the other side with a ferromagnetic powder mixed and dispersed in the synthetic resin. Since the composition described above is coated, the curl (flatness) can be improved, and it is possible to record audio information other than image information that could not be achieved by using conventional photographic printing paper. is there.

[0020]

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

Examples 1 to 4 and Comparative Example 1. Thickness 180μ
m of the base paper, the titanium oxide-containing resin composition shown in Table 1 on one surface and the ferromagnetic cobalt-modified iron oxide (C
o-γFe ₂ O ₃ ) is appropriately contained in the resin composition by melt extrusion at 300 ° C. to form a laminate layer having a thickness of 25 to 30 μm. A voice recording / playback test was performed using the head. The results are as shown in Table 1.

For the evaluation of curl, a plurality of samples were wound around respective supports on a core having a diameter of 10 cm, and the curl after standing for 6 hours in an environment of 50 ° C. was measured in a length of 5 cm × width. When a 5 cm sample was placed on a horizontal plate, the height of the sample from the horizontal plate (36 points including the four corners of the sample) was measured every 1 cm in the vertical and horizontal directions, and the standard deviation value was used. It was

[0023]

[Table 1]

Claims (4)

[Claims] 1. A composition in which a pigment is mixed and dispersed in a synthetic resin is coated on one surface of a base paper, and the other surface of the raw paper is coated with a composition in which a ferromagnetic powder is mixed and dispersed in a synthetic resin. A support for photographic printing paper. 2. The support for photographic printing paper according to claim 1, wherein the pigment is titanium oxide. 3. A composition in which a pigment is mixed and dispersed and / or a composition in which a ferromagnetic powder is mixed and dispersed contains 50% by weight or more of a resin having a solubility parameter δ ₂ of 10 or more. Item 1. A support for photographic printing paper according to Item 1. 4. The support for photographic printing paper according to claim 3, wherein the resin having a solubility parameter δ ₂ of 10 or more is polyethylene terephthalate.