JP2010242134A - Method for manufacturing laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminate having high surface flatness by suppressing undulation developed by the effect of the sputtering. <P>SOLUTION: In a laminate manufacturing method, an oxide dielectric film and/or a metal film is deposited by the sputtering method on at least one side of a long resin film substrate F. After the film deposition is executed on the long resin film substrate F to form a laminate, the laminate is subjected to the tension treatment in which the tension of 1.25N/mm<SP>2</SP>to 2.5N/mm<SP>2</SP>per unit area of a surface orthogonal to the longitudinal direction MD in the direction along the longitudinal direction MD of the long resin film substrate F at the atmospheric temperature between the glass transition temperature -35°C and the glass transition temperature +20°C of the long resin film substrate F. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing a laminate obtained by laminating an oxide dielectric film and / or a metal film on at least one surface of a long resin film substrate by a sputtering method, and in particular, at least a long resin film substrate as the laminate. The present invention relates to a method of manufacturing an absorptive multilayer ND filter having an absorptive multilayer film formed by alternately laminating oxide dielectric films and metal films on one surface by sputtering.

  A laminate in which an oxide dielectric film and / or a metal film is formed on at least one surface of a resin film substrate is widely used for optical parts and the like. An example of such a laminated body is an ND filter (Neutral Density Filter). As the ND filter, a reflection type ND filter that reflects and attenuates incident light and an absorption type ND filter that absorbs and attenuates incident light are known.

  When an ND filter is incorporated in a lens optical system in which reflected light is a problem, an absorption ND filter is generally used. This absorption type ND filter includes a type in which an absorbing substance is mixed (colored glass filter) and applied to the substrate itself, and a type in which the thin film formed on the surface of the substrate has no absorption and has absorption. . In the latter type, in order to prevent reflection on the surface of the thin film, the thin film is formed of a multilayer film (absorption type multilayer film), and has an antireflection effect as well as a function of attenuating transmitted light.

  By the way, in the method of manufacturing the ND filter, a substrate made of a long resin film (hereinafter referred to as a long resin film substrate) is used, and a multilayer made of a metal film and an oxide film on one or both sides thereof. There is a method of forming a film. For example, a method is known in which a metal film or an oxide film is formed on a surface of a long resin film substrate such as a PET film by a roll-to-roll method by a film forming method such as a sputtering method. A sputtering roll coater is generally used to form such a long PET film.

  The technique for forming a film on a long PET film is also applied to the production of a magnetic recording medium such as a magnetic tape. Conventional magnetic tapes for analog recording media have been required to reduce waviness in which the surface of the magnetic tape rises and falls in order to reduce electromagnetic conversion characteristics. However, in recent digital recording type magnetic tape, even if there is a swell component, the electromagnetic conversion characteristics are not deteriorated. Therefore, a technique for intentionally imparting swell to a base film (PET film) from the viewpoint of improving running performance is disclosed in Patent Literature. 1 is disclosed.

  Patent Document 2 proposes a method in which an optical film is sandwiched between a temperature-set molding roll and a temperature-set elastic roll for the purpose of achieving both transferability and releasability of the optical film. Has been. Specifically, both transferability and releasability are achieved by sandwiching an optical film between a forming roll set at a temperature higher than the glass transition temperature (Tg) and an elastic roll set at a temperature below Tg. The undulation of the film has not been studied.

JP-A-10-275324 JP 2007-90859 A

  In the absorption type multilayer ND filter, since it is not preferable to have undulations, it is necessary to remove the undulations. However, until now, there has been no disclosure of a method for effectively suppressing the undulation in the longitudinal direction (MD) and the width direction (TD) that occurs when an absorption multilayer ND filter is produced by roll-to-roll. .

  The present invention relates to an absorptive multilayer ND filter provided with an absorptive multilayer film in which an oxide dielectric film and a metal film are alternately laminated by sputtering on at least one surface of a long resin film substrate. The distortion generated in the long resin film substrate due to the influence causes the absorption multilayer ND filter after fabrication to swell in the longitudinal direction (MD) and the width direction (TD) when the long resin film substrate is used. The purpose is to solve the problem of expression.

  In order to solve the above-mentioned problems, the present inventor has a problem of waviness that occurs after the production of the absorption multilayer ND filter, that is, the long resin film substrate is distorted due to the influence of sputtering, which is absorbed after the production. For the problem of waviness in the direction along the longitudinal direction (MD) and the width direction (TD) when a long resin film substrate is used for the multilayer multilayer film ND filter, tension treatment is performed after the production of the multilayer multilayer film ND filter. We conducted extensive research on the effects of this.

  As a result, in the manufacture of an absorption multilayer ND filter in which an absorption multilayer film formed by alternately laminating an oxide dielectric film and a metal film by sputtering is provided on at least one surface of a long resin film substrate. After forming the absorption type multilayer film on the long resin film substrate, the inventors found that the above-mentioned problems can be solved by applying tension to the obtained absorption type multilayer film ND filter under predetermined conditions, thereby completing the present invention. .

That is, the method for producing a laminate provided by the present invention is a method for producing a laminate in which an oxide dielectric film and / or a metal film is formed by sputtering on at least one side of a long resin film substrate, After forming a laminated body by forming a film on a resin film substrate, the long resin film substrate has a glass transition temperature of −35 ° C. to an ambient temperature of glass transition temperature + 20 ° C. of the long resin film substrate. in a direction along the longitudinal direction of the case, it is characterized by performing a tension process of adding said longitudinally from 1.25 N / mm ² per unit area of a surface perpendicular of 2.5 N / mm ² tension.

  In the manufacturing method of the present invention, the produced laminate may be an absorption multilayer ND filter. In the manufacturing method of the present invention, an absorption multilayer ND filter having an absorption multilayer film in which an oxide dielectric film and a metal film are alternately laminated on at least one surface of a long resin film substrate is provided. It is preferable to perform a tension treatment that cuts in the width direction and applies a tension in the direction along the longitudinal direction of the long resin film substrate to the sheet-like absorption multilayer film ND filter obtained thereby.

  Furthermore, in the manufacturing method of the said invention, when the said long resin film board | substrate is a PET film board | substrate, it is preferable that the atmospheric temperature at the time of performing the said tension process is 25 to 90 degreeC.

  ADVANTAGE OF THE INVENTION According to this invention, the wave | undulation which expresses to the absorption type multilayer ND filter after preparation by the distortion of the elongate resin film board | substrate produced by the influence of sputtering can be suppressed. As a result, it is possible to easily obtain an absorption multilayer ND filter having high surface flatness compared to a conventional absorption multilayer ND filter, which is industrially useful.

It is a schematic diagram which shows the general structure of an absorption type multilayer ND filter. The schematic of the sputtering roll coater apparatus used suitably for the manufacturing method of the laminated body of this invention is shown. It is a schematic diagram which shows the wave | undulation height H defined by this invention. It is the schematic which shows the tension | tensile_strength addition apparatus used suitably for the manufacturing method of the laminated body of this invention. It is the schematic which shows the waviness measuring apparatus used in the Example of this invention.

  Hereinafter, embodiments of the present invention will be described in detail by taking an absorption multilayer ND filter as an example of a laminated body as an example. In the present invention, a method for manufacturing an absorption type multilayer ND filter in which an absorption type multilayer film formed by alternately laminating oxide dielectric films and metal films by sputtering is provided on at least one surface of a long resin film substrate. In the above, the obtained absorption type multilayer ND filter is subjected to a tension treatment.

  By performing tension treatment on the absorption type multilayer ND filter, the distortion generated in the long resin film substrate due to the influence of sputtering is caused to appear in the produced absorption type multilayer ND filter, in particular, the long resin film substrate. Longitudinal direction (MD) at the time of, i.e., transport direction of the long resin film substrate at the time of sputtering, and width direction (TD) at the time of the long resin film substrate, i.e., transport of the long resin film substrate at the time of sputtering. Waviness occurring in the absorption multilayer ND filter along the direction orthogonal to the direction can be suppressed.

  The absorptive multilayer ND filter of the present invention is an absorptive multilayer film in which an oxide dielectric film and a metal film are alternately laminated on at least one surface of a long resin film substrate by a sputtering method. A resin plate or a long resin film substrate serving as a substrate for this absorption multilayer ND filter includes polyethylene terephthalate (PET), polyethylene terephthalate (PEN), polyethersulfone (PES), polyarylate (PAR), polycarbonate ( PC), polyolefin (PO), norbornene, a resin plate or resin film selected from resin materials of polyimide and polyamide, or a resin plate or resin film selected from the resin material, It is composed of a composite with an acrylic organic film covering at least one side of the single body. Among these materials, PET is desirable for the long resin film substrate from the viewpoint of price.

For the oxide dielectric film, a dielectric layer of either SiO ₂ , AlO ₂ or a mixture thereof is used. Further, a metal layer containing Ni as a main component is used for the metal film. The metal layer mainly composed of Ni is preferably composed of a Ni-based alloy material to which one or more elements selected from Ti, Al, V, W, Ta, and Si are added. The addition ratio of Ti element is 5 to 15 wt%, the addition ratio of Al element is 3 to 8 wt%, the addition ratio of V element is 3 to 9 wt%, the addition ratio of W element is 18 to 32 wt%, It is preferable that the addition ratio of Ta element is 5 to 12% by weight and the addition ratio of Si element is 2 to 6% by weight.

FIG. 1 shows an example of the structure of such an absorption multilayer ND filter. Three layers of oxide dielectric films (SiO ₂ ) and two layers of metal films (Ni) are alternately laminated with a predetermined physical film thickness on both sides of a PET film substrate to form an absorption multilayer film. It is composed.

  FIG. 2 schematically shows a sputtering roll coater apparatus 10 which is an example of an apparatus for producing an absorption multilayer ND filter by forming a film on a long resin film substrate F by a sputtering method. The sputtering roll coater apparatus 10 includes many main components inside a vacuum film forming chamber 11. For example, a first roll 12 and a second roll for unwinding and winding a long resin film substrate F. 13, a can roll 14, sputtering cathodes 15 a and 15 b, guide rolls 16 a, 16 b, 16 c and 16 d.

  When performing sputtering with this sputtering roll coater apparatus 10, the long resin film substrate F is unwound from the first roll 12, guided by the guide rolls 16a and 16b, and guided to the can roller 14, where the long resin film substrate Sputtering is performed by the sputtering cathode 15 a while F is in close contact with the can roller 14. The sputtered long resin film substrate F is guided by the guide rolls 16 c and 16 d and then wound around the second roll 13.

  When sputtering by the sputtering cathode 15a is completed and the long resin film substrate F is completely wound on the second roll 13, the long resin film substrate F is then unwound from the second roll 13 with the transport direction reversed. Sputtering is performed by the sputtering cathode 15b. The sputtered long resin film substrate F is wound around the first roll 12. Thus, a laminated body is formed by sequentially repeating the film formation.

  By the way, since the long resin film substrate F is heated by sputtering at the time of film formation, the refrigerant circulates inside the can roll 14, and the long resin film substrate F is cooled at the time of sputtering. Yes. Further, in order to bring the long resin film substrate F into close contact with the can roll 14 for reliable cooling, a tension is applied to the long resin film substrate F in the longitudinal direction, that is, the conveying direction of the long resin film substrate F. It has been.

  As described above, the long resin film substrate F on which the film is formed by the sputtering roll coater 10 is cooled to some extent by the can roll 14, but heat and tension are simultaneously applied during sputtering. It is considered that these heat and tension cause distortion in the long resin film substrate F, which causes undulation and affects the quality. In particular, when a PET film is used for the long resin film substrate F, since the glass transition temperature of the PET film is 70 ° C., it is considered that it is easily affected by heat during sputtering.

  The long resin film substrate F affected by the heat and tension at the time of sputtering described above is also affected by the environment exposed thereafter. In particular, when exposed to a hot and humid environment, distortion caused by the influence of sputtering tends to cause undulation. For example, in a sheet-like absorption multilayer ND filter having a length of 330 mm and a width of 280 mm, the waviness height H exceeds 0.5 mm in the longitudinal direction (MD) or the width direction (TD) of the long resin film substrate F. May cause undulation.

  Here, the undulation height H refers to a height difference H between two points separated by a horizontal distance L on the surface of the film when the film is placed on a horizontal base so that the surface thereof faces up and down. To do. For example, FIG. 3 shows a horizontal distance in the longitudinal direction (MD) of the long resin film substrate F in the absorption multilayer ND filter N in which an oxide dielectric film and a metal film are laminated on the long resin film substrate F. A state in which the undulation of the height difference H occurs at two points separated by L is shown. In the present invention, this distance L is 50 mm.

  In the case of further processing the absorption multilayer ND filter obtained by the manufacturing method of the present invention, or in consideration of the characteristics of an optical component including the processed absorption multilayer ND filter as a component, the absorption multilayer having a diameter of 50 mm The waviness height H of the membrane ND filter is desirably 0.5 mm or less. On the other hand, according to the manufacturing method of the absorption multilayer ND filter of the present invention, as described in detail below, the swell height H of the absorption multilayer ND filter having a diameter of 50 mm is set to 0.5 mm or less. It becomes possible to do.

  Note that in an optical component including an absorption multilayer ND filter as a component, the absorption multilayer ND filter may be cut out and attached to a diameter of about 5 mm. When measuring the undulation height H of such an absorption multilayer ND filter having a diameter of about 5 mm, the curvature of the absorption multilayer ND filter having a diameter of about 5 mm is measured and converted to the undulation height H. Can be obtained.

  The method for manufacturing an absorption multilayer ND filter according to the present invention is characterized in that tension treatment is applied to the absorption multilayer ND filter. Specifically, after an absorption multilayer film is formed on a long resin film substrate, tension is applied to the absorption multilayer film ND filter in a direction along the longitudinal direction (MD) of the long resin film substrate. Process to add.

  Further, it is obtained by cutting in the width direction an absorptive multilayer film ND filter provided with an absorptive multilayer film in which an oxide dielectric film and a metal film are alternately laminated on at least one surface of a long resin film substrate. The sheet-like absorption multilayer ND filter is subjected to a process of applying tension in a direction along the longitudinal direction (MD) when the long resin film substrate is used.

  In order to perform the tension treatment, an absorption multilayer ND filter having an absorption multilayer film in which an oxide dielectric film and a metal film are alternately laminated on at least one surface of a long resin film substrate is provided in the width direction. After cutting, it is desirable to perform tension treatment on the obtained sheet-like absorption multilayer ND filter because it is simple.

  In the present invention, the tension treatment performed on the absorption multilayer ND filter is characterized by applying tension in a direction along the longitudinal direction (MD) of the long resin film substrate. Thus, the tension is applied in the direction along the longitudinal direction (MD) in the case of a long resin film substrate. The absorption multilayer ND filter after the tension is applied in this way has an extremely excellent appearance. It is because it exhibits. That is, when tension treatment is performed on the absorption multilayer ND filter to apply tension in the direction along the width direction (TD) of the long resin film substrate, the width direction is applied to the absorption multilayer ND filter surface after the tension treatment. Wrinkles are generated, resulting in an unfavorable appearance.

  In order to apply tension in the direction along the longitudinal direction (MD), a tension applying device 20 schematically shown in FIG. 4 may be used. In this tension applying device 20, a left roll 22 and a right roll 23 are arranged on the same horizontal plane so that their central axes are substantially parallel to each other inside a casing 21 that can withstand the temperature at which tensioning is performed. Yes. Fixing means such as a clip on the left roll 22 and the right roll 23 so that the longitudinal direction (MD) of the both ends of the absorption multilayer ND filter N is a long resin film substrate is perpendicular to the axes of the two rolls. It is possible to apply a tension between the two rolls by fixing them by 24 and applying a predetermined torque to the shafts of both rolls.

Although not shown, the longitudinal direction (MD) of the absorption multilayer film ND filter is a long resin film substrate on two substantially parallel axes arranged on the same horizontal plane so as to be orthogonal to the axis. The tension applied to the absorptive multilayer ND filter may be adjusted by adjusting the distance between the two shafts. The magnitude of the tension applied to the absorption type multi-layer film ND filter is a per unit area 1.25 N / mm ² at a plane perpendicular to the tensile direction and 2.5 N / mm ^2. More preferably, the per unit area 1.42N / mm ² at a plane perpendicular to the tensile direction and 1.79N / mm ^2.

For example, the absorption type multi-layer film ND long resin film substrate width 280mm filter, if the thickness 100μm, the tension applied from a unit area per 1.25 N / mm ² so that the 2.5 N / mm ² is , 35N to 70N. Further, 1.42 N / mm ² to 1.79 N / mm ² per unit area, which is a more preferable tension, corresponds to 40 N to 50 N.

When the magnitude of tension applied to the absorption multilayer ND filter is higher than ^2.5 N / mm ² per unit area, fine cracks are formed in the absorption multilayer film laminated on the absorption multilayer ND filter. Since it occurs, it is not preferable. In addition, if the tension applied to the absorptive multilayer ND filter is lower than 1.25 N / mm ² per unit area, the tension applied to the absorptive multilayer ND filter is too weak, and is caused by the influence of sputtering. Swelling in the direction along the longitudinal direction (MD) and the width direction (TD) is satisfactorily suppressed in the case of a long resin film substrate in which the distortion of the long resin film substrate is expressed in the absorption multilayer ND filter after production. It is not preferable because it becomes impossible to do so.

  The atmospheric temperature when the tension treatment is performed on the absorption type multilayer ND filter is from the glass transition temperature of −35 ° C. to the glass transition temperature of the long resin film substrate. For example, when a PET film is used for the long resin film substrate, the glass transition temperature is 70 ° C., so the atmospheric temperature is adjusted to 35 ° C. or more and 90 ° C. or less. A more preferable atmospheric temperature is 80 ° C to 85 ° C. When this temperature is higher than 90 ° C., the longitudinal direction (MD) and the width direction in the case of a long resin film substrate in which distortion of the long resin film substrate caused by the influence of sputtering is expressed in the absorption multilayer ND filter after production. This is not preferable because the undulation in the direction along (TD) cannot be satisfactorily suppressed. In addition, as a method of performing tension treatment on the absorption type multilayer ND filter within the above temperature range, for example, tension treatment may be performed in an environmental test machine.

  Thus, by performing tension treatment on the absorption multilayer film ND filter provided with the absorption multilayer film formed by alternately laminating oxide dielectric films and metal films on at least one surface of the long resin film substrate, Swelling in the longitudinal direction (MD) and width direction (TD) in the case of a long resin film substrate that causes distortion of the long resin film substrate caused by the influence of sputtering to be manifested in the absorption multilayer ND filter after production. It is possible to provide an absorption multilayer ND filter that can be suppressed and has high surface flatness with suppressed waviness as compared with a conventional absorption multilayer ND filter.

  In the above description, the description has focused on the absorption type multilayer ND filter in which the absorption type multilayer film formed by alternately laminating oxide dielectric films and metal films is provided on at least one surface of the long resin film substrate. However, the present invention is not limited to this, and it goes without saying that the present invention can be applied to other filters such as a light shielding filter in which a metal film is formed on at least one surface of a long resin film substrate.

  The absorptive multilayer ND filter manufactured by the manufacturing method of the present invention can be suitably used for an absorptive ND filter in which an absorbing substance is mixed with the substrate itself or an absorptive multilayer ND filter using a thick glass substrate. . In particular, it can be suitably used as an ND filter for a device having a small space for incorporating an ND filter such as a small thin digital camera or a mobile phone.

The present invention will be further described below using examples.
[Example 1]
For the substrate of the absorption type multilayer ND filter, polyethylene terephthalate (hereinafter referred to as PET film) (manufactured by Toyobo) having high heat resistance, high transparency in the visible wavelength range, and low water absorption was selected. FIG. 1 shows the structure of the absorption multilayer ND filter manufactured in Example 1.

An absorption multilayer film was formed by alternately laminating three layers of SiO ₂ films as oxide dielectric films and two layers of Ni layers as metal absorption films on both sides of this PET film (thickness 100 μm, width 280 μm). . A sputtering roll coater apparatus 10 (manufactured by Hirano Kotone Co., Ltd.) shown in FIG. 2 was used for film formation.

A sputtering target (Asahi Glass Ceramics Co., Ltd.) in which Si was added to SiC was mounted on the sputtering cathode 15a as a sputtering target for forming SiO ₂ that is an oxide dielectric film. Using this sputtering target, Ar gas was introduced, and a SiO ₂ film was formed by introducing a dual magnetron sputtering method while introducing oxygen gas (Ar gas pressure 150 SCCM). The amount of oxygen gas introduced was controlled by an impedance monitor (O ₂ gas pressure 5 Pa).

  Moreover, a target (manufactured by Sumitomo Metal Mining Co., Ltd.) added with Ni-Ti 8% was attached to the sputtering cathode 15b as a sputtering target for forming Ni as a metal absorption film. Using this sputtering target, Ar gas was introduced so that the Ar gas pressure was 150 SCCM, and a metal absorption film was formed by DC magnetron sputtering. In this way, a multilayer film having the thickness shown in FIG. 1 was formed.

<Tension treatment>
The absorptive multilayer film ND filter formed by the sputtering roll coater apparatus 10 of FIG. 2 is taken out and sandwiched between two dust-free papers (manufactured by Oohiro Paper Co., Ltd.) while being unwound from the roll, and is formed into a sheet (long 330 mm in width and 280 mm in width). The dust-free paper having a thickness of 0.08 mm, a length of 330 mm, and a width of 280 mm was used.

Both ends of the absorption-type multilayer ND filter sandwiched between two dust-free papers are respectively fixed to the right roll 22 and the left roll 23 of the tension applying device 20 shown in FIG. ). The tension between the two rolls was set to 50 N (1.79 N / mm ² per unit area), and the tension treatment was performed at a temperature of 85 ° C. for 1 hour.

<Measurement method of swell>
In order to evaluate whether the undulation generated in the absorption type multilayer ND filter is suppressed by the tension treatment, in the absorption type multilayer ND filter cut to 330 mm in length and 280 mm in width, the longitudinal direction when the PET film substrate is used (MD), the undulation height H generated in the width direction (TD) was measured. For this measurement, a swell measuring device 30 shown in FIG. 5 was used. The waviness measuring device 30 places an absorption multilayer ND filter N cut into a length of 330 mm and a width of 280 mm to be detected on a horizontal measurement table 31 so that the surface thereof faces up and down. The undulation height is detected by irradiating the light beam 34 from the transmitter 32 provided opposite to both ends of the laser beam toward the receiver 33.

  As a result of detection by the undulation measuring device 30, the longitudinal direction (MD) and the width direction (TD) of the PET film substrate when the absorption multilayer film ND filter according to Example 1 is subjected to tension treatment using the tension applying device 20. ) Is lower than 0.2 mm per 50 mm diameter, which is the detection limit of the undulation measuring device 30, and could not be detected. That is, it was found that the surface flatness was so high that it could not be detected by the tension treatment.

[Comparative Example 1]
The absorbing multilayer ND filter was subjected to tension treatment in the same manner as in Example 1 except that the tension was 75 N (2.7 N / mm ² per unit area). When the size of the waviness of the absorption multilayer ND filter according to Comparative Example 1 obtained was measured using the waviness measuring device 30 shown in FIG. 5, the waviness heights in the longitudinal direction (MD) and the width direction (TD) were measured. H was lower than 0.2 mm per 50 mm diameter, which is the detection limit of the undulation measuring device 30, and could not be detected. As in Example 1, the surface flatness was high. However, fine cracks have occurred in the absorption multilayer film laminated on the absorption multilayer film ND filter.

[Comparative Example 2]
The absorptive multilayer ND filter was subjected to tension treatment in the same manner as in Example 1 except that the tension was 30 N (1.07 N / mm ² per unit area). When the size of the undulation of the absorption multilayer ND filter according to Comparative Example 2 obtained is measured using the undulation measuring device 30 shown in FIG. 5, the undulation height in the longitudinal direction (MD) and the width direction (TD) is obtained. H was 1.5 mm per 50 mm diameter.

[Comparative Example 3]
The absorption multilayer ND filter was subjected to tension treatment in the same manner as in Example 1 except that the treatment was performed at a temperature of 95 ° C. When the size of the undulation of the absorption multilayer ND filter according to Comparative Example 3 obtained is measured using the undulation measuring device 30 shown in FIG. 5, the undulation height in the longitudinal direction (MD) and the width direction (TD) is obtained. H was 2.0 mm per 50 mm diameter.

[Comparative Example 4]
Tensile treatment was performed on the absorption-type multilayer ND filter in the same manner as in Example 1 except that the tension treatment for applying tension in the width direction was treated in the width direction (TD). When the size of the waviness of the absorption multilayer ND filter according to Comparative Example 4 obtained was measured using the waviness measuring device 30 shown in FIG. 5, the waviness heights in the longitudinal direction (MD) and the width direction (TD) were measured. H was able to suppress waviness at 0.5 mm per 50 mm diameter. However, wrinkles in the width direction (TD) are generated on the absorption multilayer ND filter surface, which is not preferable in appearance.

  From the results of Example 1 and Comparative Examples 1 to 4 described above, in Example 1, by performing tension treatment at a tension of 50 N and a temperature of 85 ° C. for 1 hour, distortion caused by the influence of sputtering is an absorption multilayer film after production. It was found that waviness in the longitudinal direction (MD) and the width direction (TD) to be expressed in the ND filter can be satisfactorily suppressed.

  On the other hand, in Comparative Example 1, the treatment in the tension of 75 N suppresses the undulation in the longitudinal direction (MD) and the width direction (TD) that causes the distortion caused by the sputtering to appear in the absorption multilayer ND filter after fabrication. However, since the cracks occurred in the absorption multilayer film laminated on the absorption multilayer film ND filter, it was not industrially effective.

  Further, in the tension treatment at a tension of 30 N in Comparative Example 2 and the tension treatment at a temperature of 95 ° C. in Comparative Example 3, the longitudinal direction (MD) in which distortion caused by the sputtering is developed in the produced absorption multilayer ND filter. ) And the undulation in the width direction (TD) could not be suppressed.

  Furthermore, in Comparative Example 4, by performing the tension treatment in the width direction (TD), the longitudinal direction (MD) and the width direction (TD) cause distortion caused by the sputtering to appear in the fabricated absorption multilayer ND filter. Although it was possible to suppress the undulation, wrinkles in the width direction (TD) were generated on the surface of the absorption type multilayer ND filter, which was not preferable in appearance.

10 Sputtering roll coater device 20 Tension applying device 30 Waviness measuring device F Long resin film substrate

Claims (4)

In a method for manufacturing a laminate in which an oxide dielectric film and / or a metal film is formed on at least one side of a long resin film substrate by a sputtering method, after forming a laminate on a long resin film substrate, The longitudinal direction in the direction along the longitudinal direction of the long resin film substrate with respect to the laminate at an atmospheric temperature from the glass transition temperature of −35 ° C. to the glass transition temperature + 20 ° C. of the long resin film substrate method for producing a laminate, which comprises carrying out the tension processing tensioning the per unit area 1.25 N / mm ² of 2.5 N / mm ² in a plane perpendicular to the.   The method for manufacturing a laminate according to claim 1, wherein the laminate is an absorption multilayer ND filter.   Sheet obtained by cutting in the width direction an absorptive multilayer ND filter provided with an absorptive multilayer film in which oxide dielectric films and metal films are alternately laminated on at least one side of the long resin film substrate 3. The laminated body according to claim 1 or 2, wherein a tension treatment is applied to the shaped absorption multilayer ND filter to apply a tension in a direction along a longitudinal direction of the long resin film substrate. Production method.   4. The laminate according to claim 1, wherein the long resin film substrate is a PET film substrate, and an atmospheric temperature at the time of performing the tension treatment is 25 ° C. to 90 ° C. 5. Production method.

Images