JPH11352637A - Production of base for photographic paper and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to drastically lessen the generation of craters and to substantially prevent the increase of a running cost even if a base for photographic paper is produced by increasing the traveling speed of a base material. SOLUTION: A resin film 11 in a molten state discharged from an extrusion die 12 is applied on the surface of the traveling base material 22 and thereafter, a first nipping operation is carried out between a cooling roller 14 and a first nip roller 16, by which a laminate 26 consisting of the base material 22 and the resin film 11 is formed. Next, the nipping operation is again carried out between renipping rollers 20 and the cooling roller 14 while the resin film 11 of the laminate 26 is still in the molten state. As a result, even if the craters are generated on the resin film surface by the first nipping operation for press bonding the resin film 11 to the base material surface, the resin film surface is smoothed and flattened by the roller effect of the renipping rollers 20 by the renipping operation and, therefore, the craters generated by the first nipping operation may be drastically decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a photographic printing paper support, and more particularly to a photographic printing paper support for manufacturing a photographic printing paper support having no craters. The present invention relates to a manufacturing method and an apparatus.

[0002]

2. Description of the Related Art As shown in FIG. 3, a substrate having irregularities such as paper is coated with a resin film to produce a support for photographic printing paper. Is extruded into a film shape on a belt-shaped base material 3 running from an extrusion die 2 in a heated and molten state, and the resin film 4 and the base material 3 are nipped between a nip roller 5 and a cooling roller 6 and pressed. Extrusion lamination method (also called extrusion coating method) for laminating a resin film to a substrate
Has been widely adopted. Reference numeral 7 denotes a backup roller, and reference numeral 8 denotes a peeling roller.

In the production of this photographic paper support,
Due to entrainment of air from a cooling roller, etc., fine pores (hereinafter, referred to as
Craters). And
When the number of the craters is large, the appearance of the product is impaired, and when used as a support for photographic printing paper, the glossiness is also reduced, so that the value of the product is significantly reduced.

[0004] With regard to pores generated on the surface of the resin film called craters, nips occur as the line speed, which is the running speed of the base material, increases, as the thickness of the resin film to be laminated decreases, and as the temperature of the molten resin decreases. It is known that the lower the pressure and the greater the surface roughness of the substrate, the more easily the pressure is generated. As a prior art that discloses measures to prevent craters, for example, those examined from the aspect of resin to be laminated as in Japanese Patent Application Laid-Open No. 8-36238, and those on the surface of a base material as described in Japanese Patent Application Laid-Open No. 4-81836. Japanese Unexamined Patent Application Publication No. 6-214342 discloses a method in which the manufacturing process conditions are specified.
There has been proposed a new facility as disclosed in Japanese Patent Publication No. 3-246227.

[0005]

However, any of the above-mentioned techniques are inadequate as measures for preventing the occurrence of craters, and also have the disadvantage of increasing running costs and other costs. In particular, in the case of a high-speed production in which the running speed of the base material, that is, the line speed exceeds 450 m / min, the above-described technique has almost no effect.

The present invention has been made in view of such circumstances, and even if a photographic printing paper support is manufactured by increasing the running speed of a substrate, the occurrence of craters can be significantly reduced. It is an object of the present invention to provide a method and an apparatus for manufacturing a photographic printing paper support that hardly raises running costs.

[0007]

According to the present invention, in order to achieve the above object, a resin film in a molten state is coated on a substrate, and the substrate and the resin film are interposed between a nip roller and a cooling roller. In a method for manufacturing a support for photographic printing paper, wherein the resin film is laminated on the substrate by nip and pressure bonding, immediately after the first nip operation of laminating the resin film on the substrate, The method is characterized in that a re-nip operation for re-nip between the substrate and the resin film is performed at least once.

According to another aspect of the present invention, a resin film in a molten state is coated on a substrate, and the substrate and the resin film are nip-bonded between a nip roller and a cooling roller. In the photographic printing paper support manufacturing apparatus for manufacturing by laminating the resin film on the substrate by doing, after the first nip roller for laminating the resin film on the substrate, the cooling roller At least one re-nip roller for nip between the base material and the resin film again is provided.

According to the present invention, even if a crater is generated on the surface of the resin film at the time of the first nip operation for laminating the resin film on the base material, the nip operation is performed again immediately after the first nip operation. The generated craters can be reduced. In this case, it is preferable to perform the re-nip operation while the resin is still in a molten state. Further, in order to achieve the above object, the present invention covers the base material surface with a resin film in a molten state, then nips the base material and the resin film between a nip roller and a cooling roller and press-bonds the same. In a manufacturing apparatus for a photographic paper support for laminating a film-like resin film on the substrate surface by cooling and solidifying the resin film, after the first nip operation of pressing the resin film on the substrate surface, A heating roller and a re-nip roller for re-nip between the substrate surface and the resin film are provided.

According to the present invention, after the first nip operation of pressing the resin film on the substrate surface is performed, the resin film is heated and melted again by the heating roller, and then the heating roller and the re-nip roller are used. Since re-nip can be performed, even if a crater is generated on the surface of the resin film at the time of the first nip operation, the generated crater can be reduced by performing the nip operation again immediately after the first nip operation.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a method and an apparatus for manufacturing a photographic printing paper support according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is an overall configuration diagram of an apparatus 10 for manufacturing a photographic printing paper support according to the first embodiment of the present invention.

As shown in FIG. 1, below an extrusion die 12 from which a molten thermoplastic resin film 11 is discharged,
The cooling roller 14 and the first nip roller 16 are arranged in parallel and adjacent to each other, and the peeling roller 18 is arranged adjacent to and in parallel with the cooling roller on the opposite side of the first nip roller 16 with the cooling roller 14 interposed therebetween. . Further, a backup roller 17 is provided on the opposite side of the first nip roller 16 from the cooling roller 14.

In the vicinity of the first nip roller 16, a plurality of re-nip rollers 20, 20, 20 are arranged adjacent to the cooling roller 14. Then, the band-shaped base material 22
Travels in the direction of the arrow while passing through the cooling roller 14, the first nip roller 16, the plurality of re-nip rollers 20, and the peeling roller 18 while contacting the peripheral surface of the cooling roller 14. The re-nip roller 20 is provided with a pressing force adjusting device 2 that slides the re-nip roller 20 so that the pressing force against the cooling roller 14 can be adjusted.
4, 24, 24 are provided.

As the substrate in the present invention, paper, resin, or metal can be used depending on the required laminate. Further, as the thermoplastic resin, a known thermoplastic resin such as a polyolefin resin such as polyethylene and polypropylene can be used. Next, the operation of the apparatus for manufacturing a photographic printing paper support according to the first embodiment of the present invention configured as described above will be described.

After the molten resin film 11 discharged from the extrusion die 12 is coated on the surface of the running base material 22, the first nip operation is performed between the cooling roller 14 and the first nip roller 16. Will be In the first nip operation, the backup roller 17 presses the first nip roller 16 against the cooling roller 14 with a pressure necessary for the resin film 11 to be pressed against the substrate surface. As a result, the resin film 11 coated on the substrate surface is pressed against the substrate surface,
And a laminate 26 made of the resin film 11 is formed.
Next, while the resin film 11 of the laminate 26 is still in a molten state, the nip operation is performed again between the re-nip roller 20 and the cooling roller 14. Thereby, even if a crater is generated on the resin film surface by the first nip operation for pressing the resin film 11 against the base material surface, the resin film surface is leveled by the roller action of the re-nip roller 20 by the re-nip operation. Therefore, the crater generated in the first nip operation can be significantly reduced. Also, by performing the re-nip, even when the line speed is increased or when the amount of resin is reduced and the resin film 11 is thinly laminated on the substrate surface, the surface of the resin film 11 has less craters and good gloss. A photographic printing paper support having excellent flatness can be manufactured.

In this re-nip operation, the craters decrease as the nip pressure is increased. However, if the nip pressure is excessively increased, the influence of the irregularities on the substrate surface becomes strong and the reverse effect occurs. The pressing force by which the re-nip roller 20 presses the cooling roller 14, that is, the nip force, is adjusted by the pressing force adjusting device 24 in accordance with the degree of unevenness of the surface, the thickness of the resin film 11, and the like. The effect of the re-nip operation is greater as the fluidity of the resin film 11 is higher (the temperature of the resin film is higher). However, when the resin film 11 comes into contact with the cooling roller 14, the resin film 11 tends to be rapidly cooled and solidified. Roller for re-nip 2
0 is preferably arranged as close as possible to the first nip roller 16.

Although one re-nip roller 20 is effective, in particular, when the line speed, which is the running speed of the substrate 22, exceeds 450 m / min, the re-nip roller 20 shown in FIG. It is preferable to provide a plurality of re-nip rollers 20 so as to exert the roller action in multiple stages. Further, it is more effective to provide a plurality of re-nip rollers 20 and to increase the nip force as the re-nip roller 20 is located farther from the first nip roller 16. That is, the re-nip roller 20 close to the first nip roller 16 is
The nip is performed while the fluidity of the resin film 11 is still high. Therefore, the crater can be easily extinguished even if the nip force is not increased, and if the nip force is too large, the unevenness of the substrate surface will affect the crater. Then, as the re-nip roller 20 is farther from the first nip roller 16, the resin film 11 is cooled and nips in a state where the fluidity is low. Therefore, if the nip pressure is not increased, the craters are less likely to disappear, and even if the nip pressure is increased, the influence of the unevenness of the substrate surface is less likely to occur.

The re-niped laminate 26 is then peeled off from the cooling roller 14 by a peeling roller 18, whereby a photographic paper support having the resin film 11 laminated on the substrate surface is manufactured. FIG. 2 is an overall configuration diagram of a photographic printing paper support manufacturing apparatus 30 according to a second embodiment of the present invention. The same members as those in the first embodiment are denoted by the same reference numerals and described.

In the second embodiment of the present invention, a resin film 11 is coated on a substrate surface, and then the resin film 11 is pressed on the substrate surface to form a laminate 26 after the first nip operation. And a heating roller 28 for re-nipping the laminated material 26 and a re-nip roller 34. That is, after the resin film 11 in the molten state discharged from the extrusion die 12 is coated on the surface of the traveling base material, the cooling roller 14
The first nip operation is performed with the nip roller 16. As a result, the resin film 11 coated on the base material surface is pressed on the base material to form a laminate 26 composed of the base material 22 and the resin film 11. Next, after the laminate 26 is separated from the cooling roller 14 by the separation roller 18, the laminate 26 passes between the engagement roller 32 and the heating roller 28, and
It travels while touching the eight peripheral surfaces. Thereby, the resin film 11 of the laminate 26 cooled and solidified by the cooling roller 14 is formed.
Is again heated and melted. The heat-melted laminate 26 is re-niped by the heating roller 28 and the re-nip roller 34. Accordingly, even if a crater is generated on the resin film surface by the first nip operation for pressing the resin film 11 against the base material surface, the resin film 11 is re-nipped while being heated and melted again. The roller action of the nip roller 34 can be more effectively exerted. Therefore, craters generated in the first nip operation can be more effectively reduced.

In FIG. 2, only one re-nip roller 34 is shown. However, if a plurality of re-nip rollers 34 are provided along the peripheral surface of the heating roller 28, especially in the case of high-speed production in which the line speed is increased. It is effective for The method of heating and melting the resin film 11 again is not particularly limited to the heating roller 28, but may be re-nipped by a pair of nip rollers in a drying device. Can be heated to above the melting point.

[0021]

EXAMPLE In this example, the thickness was 175 μm and the width was 300 m.
A resin film obtained by mixing 10 wt% of titanium oxide with low-density polyethylene having a melt flow rate of 7.0 and a density of 0.916 g / cm ³ is laminated on the surface of a base material (base paper) having a thickness of 30 μm. did. The temperature of the resin film in the molten state was set at 315 ° C., and the line speed, which is the traveling speed of the base material, was 200 m / min, which is a general speed, and was 450 m / min, which is a high speed. The nip pressure for the first nip operation for pressing the resin film on the base material surface is 30 kg /
cm ² .

The results obtained are shown in Table 1. Note that, in Table 1, Examples 1 to 4 are cases where the production was performed using the manufacturing apparatus of FIG. 1 described in the first embodiment, and
6 shows a case where the production was performed using the manufacturing apparatus of FIG. 2 described in the second embodiment. Further, Comparative Examples 1 and 2 are cases in which the re-nip operation was performed using a conventional manufacturing apparatus that did not perform the re-nip operation.

As a method for evaluating the craters of the examples or comparative examples, five sample areas having an area of 0.4 cm ² were randomly selected from the resin film surface of the manufactured photographic printing paper support, and each sample was selected. The range was magnified 50 times with an optical microscope, and the number of craters having a diameter of 50 μm or more was counted. And the average value which averaged the number of craters of five sample ranges was made into the number of craters of an Example or a comparative example, and was classified into the following five grades.

Grade 1: The number of craters is 20 or more. Grade 2: The number of craters is 15 or more and less than 20 Grade 3: The number of craters is 10 or more and less than 15 Grade 4: The number of craters is 5 or more and less than 10 Grade 5: The number of craters is less than 5

[0025]

[Table 1] As can be seen from the results in Table 1, in the case of the comparative example, the evaluation of the crater was 3 in the case of the comparative example 1 in which the line speed was 200 (m / min), and the line speed was increased to 450 (m / min). In the case of Comparative Example 2, the evaluation of the crater is deteriorated to 1.

On the other hand, in the examples of the present invention, the crater evaluation was 5 in Examples 1, 3, and 5 in which the line speed was 200 (m / min). If the line speed is 4
Even when the speed was increased to 50 (m / min), the evaluation of the crater in Example 4 was 5, and in the case of Examples 2 and 6,
The crater rating was 4. From these results, it was found that the number of craters on the resin film surface was significantly reduced by performing the method for producing a photographic printing paper support of the present invention as compared with the comparative example.

Also, from the comparison of the case where the line speed is increased in the second, fourth and sixth embodiments, immediately after the first nip operation,
It was found to be more effective to re-nip re nip pressure (50kg / cm ²⁾ higher than the pressure of the first nip operation (30kg / cm ^2).

[0028]

As described above, according to the method and apparatus for manufacturing a photographic printing paper support of the present invention, the crater is applied to the resin film surface by the first nip operation for pressing the resin film to the substrate surface. Occurs, the resin film surface is leveled and flattened by the roller action of the re-nip roller by the re-nip operation, so that the crater generated in the first nip operation can be significantly reduced.

Also, by performing the re-nip, even when the line speed is increased or when the amount of resin is reduced and the resin film is thinly laminated on the base material surface, the surface of the resin film has little crater and gloss. A support for photographic printing paper having good flatness can be produced.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an apparatus for manufacturing a photographic printing paper support according to a first embodiment of the present invention.

FIG. 2 is an overall configuration diagram of an apparatus for manufacturing a photographic printing paper support according to a second embodiment of the present invention.

FIG. 3 is an overall configuration diagram of a conventional photographic printing paper support manufacturing apparatus.

[Explanation of symbols]

 10, 30: Apparatus for manufacturing a photographic paper support 12: Extrusion die 14: Cooling roller 16: First nip roller 18: Peeling roller 20, 34: Re-nip roller 22: Base material 24: Pressing force adjusting device 26 ... Laminate 28 ... Heating roller

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tadashi Ueda 200 Onakazato, Fujinomiya City, Shizuoka Prefecture Inside Fuji Photo Film Co., Ltd.

Claims (4)

[Claims] 1. A method in which a resin film in a molten state is coated on a surface of a base material, and the base material and the resin film are nipped and pressed between a nip roller and a cooling roller, and the resin film is cooled and solidified. In a method for manufacturing a photographic printing paper support for laminating a film-like resin film on a substrate surface, immediately after a first nip operation of pressing the resin film on the substrate surface, the substrate and the resin film A method for producing a support for photographic printing paper, wherein a re-nip operation for re-nipping is performed at least once. 2. The method for manufacturing a photographic printing paper support according to claim 1, wherein said re-nip operation is performed after heating and melting the resin film coated on said base material again. 3. A method in which a resin film in a molten state is coated on a base material surface, and the base material and the resin film are nipped and pressed between a nip roller and a cooling roller, and the resin film is cooled and solidified. In a photographic printing paper support manufacturing apparatus for laminating a film-shaped resin film on a substrate surface, after the first nip roller for pressing the resin film on the substrate surface, the substrate between the cooling roller And at least one re-nip roller for nipping the resin film again. 4. A method in which a base material surface is coated with a molten resin film, and then the base material and the resin film are nipped and pressed between a nip roller and a cooling roller, and the resin film is cooled and solidified. In an apparatus for manufacturing a photographic printing paper support for laminating a film-like resin film on a substrate surface, the substrate surface and the resin film are provided after the first nip operation of pressing the resin film on the substrate surface. An apparatus for manufacturing a photographic printing paper support, further comprising a heating roller for re-nipping and a re-nip roller.