JPH05265133A - Production of substrate for photographic printing paper - Google Patents

Abstract

PURPOSE:To provide the production method of a substrate for photographic printing paper having satisfactory water resistance, surface smoothness and glossiness and excellent in dose adhesion. CONSTITUTION:When titanium oxide is mixed and dispersed in a resin contg. 10-100wt.% polyethylene terephthalate and one side of base paper is coated with the resulting compsn. by melt extrusion to produce the substrate for photographic printing paper, the melt extrusion of the compsn. is carried out on the front side of the base paper heated to >=70 deg.C.

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 support for photographic printing paper, and more particularly to a method for producing a support for photographic printing paper which is excellent in adhesion between a resin layer and a base paper.

[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 polyolefin resin layer such as polyethylene containing titanium oxide mixed and dispersed. Is being done. In this case, titanium oxide enhances the image quality by increasing the whiteness of the photographic paper in particular, while it works to deteriorate the flatness of the surface of the photographic paper.

However, in the photographic printing paper having a glossy surface, which is most widely used at present, it is required to further improve the smoothness and glossiness of the surface of the printing paper in order to improve the appearance of the image. ing. Therefore, it has been proposed to use polyethylene terephthalate instead of polyolefin to improve the smoothness and glossiness of the surface of photographic paper (for example, Japanese Patent Application No. 3-899).
No. 83).

[0004]

However, since the polyethylene terephthalate resin layer is inferior in adhesiveness to the base paper as compared with the polyolefin resin layer, when the photographic paper is immersed in water for a long time at the time of development or the like, However, there is a drawback that the resin layer is easily peeled off from the base paper (poor adhesion).

The present inventors have conducted extensive studies to solve the above-mentioned drawbacks, and as a result, have found that polyethylene terephthalate is 10
It is possible to improve the adhesiveness between the polyethylene terephthalate resin layer and the base paper by casting and laminating a composition in which titanium oxide is mixed and dispersed in a resin containing 100% by weight on the surface of the base paper heated to 70 ° C. or higher. The inventors have found out what can be done and have reached the present invention. Therefore, it is an object of the present invention to provide a method for producing a support for photographic printing paper, which has excellent water resistance, surface smoothness and glossiness and excellent adhesion.

[0006]

The above objects of the present invention are as follows.
A method for producing a support for photographic paper, comprising melt-extruding a composition obtained by mixing and dispersing titanium oxide in a resin containing 10 to 100% by weight of polyethylene terephthalate, the melt-extruding method comprising: To 70
It was achieved by a method for producing a support for photographic printing paper, which is characterized in that it is carried out on the surface of a base paper heated above ℃.

The resin used in the present invention is preferably a resin containing 10 to 100% by weight of polyethylene terephthalate from the viewpoint of improving the glossiness of photographic printing paper. Other resins added to polyethylene terephthalate (referred to as blend resins) are polyolefin resins such as polyethylene and polypropylene, polyether resins such as polyethylene glycol, polyoxymethylene and polyoxypropylene, urethane resins such as polyester polyurethane and polyether polyurethane. The resin can be appropriately selected and used from resins that can be extruded at 270 to 350 ° C., such as polycarbonate, polystyrene and the like. Two or more kinds of the above blended resins may be used at the same time.

The mixing ratio of the polyethylene terephthalate and the blended resin is appropriately determined depending on the degree of polymerization and the kind of the blended resin used. In the case of the polyolefin resin, the blending ratio of the blended resin to the polyethylene terephthalate is 100: by weight. It is preferably in the range of 0 to 10:90. When the blended resin is mixed in an amount of 90% by weight or more, the resulting photographic printing paper support has reduced rigidity and insufficient surface gloss.

The form of titanium oxide used in the present invention may be either anatase type or rutile type.
The average particle size is preferably 0.1 to 0.8 μm. When it is 0.1 μm or less, it becomes difficult to uniformly mix and disperse it in the resin layer, and when it is 0.8 μm or more, the smoothness of the surface of the photographic printing paper support cannot be obtained and it is white. The degree is insufficient. The content of titanium oxide in the composition is preferably 2 to 45% by weight, and particularly preferably 5 to 35% by weight. The mixing of the above-mentioned resin such as polyethylene terephthalate and titanium oxide can be easily performed according to a conventional method.

In the present invention, a composition (referred to as a resin composition) in which titanium oxide is mixed and dispersed in a resin containing 10 to 100% by weight of polyethylene terephthalate is melted,
From the viewpoint of improving the adhesion between the resin layer and the base paper, the support for photographic printing paper is manufactured by casting on the surface of the base paper heated to 70 ° C. or higher and laminating. When the temperature of the base paper surface is 70 ° C. or lower, there is no effect on the adhesiveness. In particular, if the temperature is 100 ° C. or higher, the same adhesiveness as that obtained by laminating a polyolefin on a base paper is produced. Furthermore,
When the temperature is 140 ° C. or higher, the adhesion is better than that of photographic printing paper using ordinary polyolefin.

The resin composition can be melt-extruded and laminated on the base paper easily by using a known melt-extrusion laminating machine. The thickness of the resin layer coated on the base paper is preferably in the range of 5 to 50 μm, and particularly preferably in the range of 10 to 30 μm.
When the thickness is 50 μm or more, cracks and the like are likely to occur in the coating layer, and when it is 5 μm or less, the waterproof property of the support for photographic printing paper is insufficient and the rigidity is lowered, which is not preferable. 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 treatment. By coating a photographic emulsion layer on the titanium oxide-containing coating layer of the support obtained as described above in a known manner, not only the water resistance but also the whiteness and glossiness are excellent, and the conventional polyolefin is used. It is possible to manufacture a photographic printing paper that is excellent in adhesiveness to the same extent as the used photographic printing paper.

[0013]

According to the production method of the present invention, since the base paper surface is coated with a resin containing polyethylene terephthalate, which is inherently superior in surface smoothness to polyolefin, water resistance, whiteness and adhesion are improved. It is possible to produce a support for photographic printing paper which is maintained at a level higher than conventional and has improved surface smoothness and glossiness.

[0014]

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 Examples 1 to 3.175 g
/ M on one surface of the ^second sheet, the titanium oxide-containing resin composition shown in Table 1 was melt-extruded at 300 ° C., 25 to 30
A μm laminated layer was formed. The results of the following evaluations of the obtained support are as shown in Table 1.

The surface gloss was evaluated using a handy gloss meter HG-246 (trade name, manufactured by Suga Co., Ltd.).

Adhesiveness Adhesive tape with a width of 1 cm was attached to the resin laminate layer surface,
By peeling the adhesive tape at an angle of 180 degrees, the peeling force when the laminate layer was peeled off was measured and evaluated.

[0018]

[Table 1]

Claims (1)

[Claims] 1. Polyethylene terephthalate 10 to 1
A method for producing a support for photographic printing paper, comprising melt-extruding a composition prepared by mixing and dispersing titanium oxide in a resin containing 100% by weight, the melt-extrusion being performed at 70 ° C. or higher. A method for manufacturing a support for photographic printing paper, which is characterized in that it is carried out on the surface of the base paper heated to above.