Method for manufacturing a laminated film and manufacturing apparatus

Abstract

To make it possible to form uniform coating film, and to form a coating film with excellent external appearance and excoriation resistance.SOLUTION: A laminated film manufacturing method includes a coating process in which a coating liquid (2) is applied onto a base material film (1) by use of a gravure roll (3) to form a coating film (4). In the coating process, a ratio (Vr / Vf) of a rotational speed (Vr) of the gravure roll (2) to a transportation speed (Vf) of the base material film (1) is 30 to 60, and a water vapor content in the coating process is 10 to 25 g / m3.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method and an apparatus for manufacturing a laminated film.

Background Art

[0002] For the flexibilization of displays such as smartphones, flexible film materials are being considered as an alternative to rigid glass materials. Further, as a layer formed on the outermost surface of such a film material, the use of a layer for imparting fingerprint resistance (hereinafter sometimes referred to as AF: Anti-Fingerprint) is being considered.

[0003] Regarding the coating of a fingerprint-resistant layer on such a film material, conventionally, methods such as forming an AF layer by vapor deposition, imparting an AF layer by spray coating, and forming a coating film on a base film using a coating roll have been proposed.

[0004] Among these, as a method of forming a coating film on a base film using a coating roll, a gravure coating method is known. The method includes a coating step of applying a coating liquid using a gravure roll to form a coating film on a base film. The gravure roll is a roll having recesses for holding the coating liquid formed on its peripheral surface. In the coating step, when the coating liquid is supplied to the gravure roll, the coating liquid is temporarily held in the recesses. Then, when the gravure roll contacts the continuously conveyed base film, the coating liquid in the recesses is applied to the base film.

[0005] Patent Document 1 discloses a technique using a gravure roll having spiral diagonal cells on its roll peripheral surface and having its outermost surface coated with diamond-like carbon in a gravure coating method. Further, Patent Document 2 discloses a technique of performing plasma irradiation on a base film before applying a coating liquid.

Prior Art Documents

Patent Documents

[0006] Patent Document 1 Japanese Patent Application Laid-Open No. 2015-223552 Patent Document 2 Japanese Patent Application Laid-Open No. 2010-125358 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] However, when applying the fingerprint-resistant layer to the base film, in the techniques disclosed in Patent Documents 1 and 2, it is difficult to form a highly accurate and uniform coating film in both cases, and there is room for improvement in terms of the appearance and scratch resistance of the coating film.

[0008] One aspect of the present invention aims to realize a method and an apparatus for manufacturing a laminated film that can form a uniform coating film and a coating film excellent in appearance and scratch resistance. MEANS FOR SOLVING THE PROBLEMS

[0009] In order to solve the above problems, one aspect of the present invention has the following configuration.

[0010] (1) A coating step of applying a coating liquid using a gravure roll on a base film to form a coating film, in which, in the coating step, the ratio (Vr / Vf) of the rotational speed (Vr) of the gravure roll to the conveyance speed (Vf) of the base film is 30 to 60, and the amount of water vapor in the coating step is 10 to 25 g / m 3 , a method for manufacturing a laminated film.

[0011] (2) The method for manufacturing a laminated film according to (1), wherein the rotational directions of the gravure roll and the conveyance roll of the base film are different from each other.

[0012] (3) The method for manufacturing a laminated film according to (1) or (2), including a drying step of drying the coating film formed in the coating step.

[0013] (4) The coating liquid contains a solvent and a resin soluble in the solvent, the solid content concentration of the coating liquid is 0.05 to 0.5%, the viscosity of the coating liquid is 0.1 to 100 mPa·s, and the film thickness of the coating film is 10 to 50 nm. A method for manufacturing a laminated film according to any one of (1) to (3).

[0014] (5) The coating liquid is a fluorine-based coating liquid. A method for manufacturing a laminated film according to any one of (1) to (4).

[0015] (6) The coating film is an anti-fingerprint layer. A method for manufacturing a laminated film according to any one of (1) to (5).

[0016] (7) A manufacturing apparatus for a laminated film, comprising a coating section having a gravure roll for applying a coating liquid onto a base film conveyed by a conveyance roll to form a coating film, wherein the ratio (Vr / Vf) of the rotation speed (Vr) of the gravure roll to the conveyance speed (Vf) of the base film is set to be 30 to 60, and the amount of water vapor in the coating section is adjusted to 10 to 25 g / m 3 A manufacturing apparatus for a laminated film.

Advantages of the Invention

[0017] According to one aspect of the present invention, a uniform coating film can be formed, and a coating film excellent in appearance and scratch resistance can be formed.

Brief Description of the Drawings

[0018]

Figure 1

Modes for Carrying Out the Invention

[0019] Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited thereto, and various modifications are possible within the described scope. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments and examples are also included in the technical scope of the present invention. In this specification, unless otherwise specified, "A~B" representing a numerical range means "A or more (including A and greater than A), B or less (including B and less than B)".

[0020] 〔Technical idea of an embodiment of the present invention〕 In the coating of the fingerprint-resistant layer on the substrate film (optical film), the produced laminated film is required to have AF properties and appearance that can replace glass materials. Due to the balance with flexibility, the substrate film itself has a low hardness. Furthermore, there are irregularities of 1 to 2 μm on the surface of the substrate film, and due to this, the substrate film has thickness unevenness. For this reason, in the coating of the fingerprint-resistant layer on the substrate film, it has been difficult to coat the coating film uniformly and to achieve satisfactory AF properties and appearance.

[0021] The coating liquid for the fingerprint-resistant layer is very likely to become turbid and is easily affected by the coating method and the irregularities of the substrate film. In the coating surface of the substrate film, when a locally thick portion is formed, the coating film becomes turbid, while in a thin portion, it is a defect in terms of scratch resistance.

[0022] Also, for the coating of the fingerprint-resistant layer on the substrate film, it is preferable to coat a thin film with a thickness of about 10 to 30 nm with high precision. When coating the fingerprint-resistant layer by the gravure coating method, it becomes a problem to form a uniform coating film with excellent appearance and scratch resistance with high precision in a Roll to Roll manner. In particular, for the fingerprint-resistant layer, even if there is a difference of several nm in thickness, it becomes visibly turbid and the appearance is poor. For this reason, when performing gravure coating, it is necessary to apply high shear to the coating liquid.

[0023] In the technique described in Patent Document 2, only a gravure roll may be used as a pickup roll, and the roll for coating the base material is a rubber roll. Further, the technique described in Patent Document 2 assumes coating on a metal base material and does not require coating accuracy for an optical film. Furthermore, in the technique described in Patent Document 2, since the ratio (Vr / Vf) of the rotational speed (Vr) of the gravure roll as a pickup roll to the conveyance speed (Vf) of the base material film is less than 3, a uniform AF coating film cannot be formed with high precision.

[0024] Therefore, the present inventor has intensively studied coating by a gravure coating method capable of forming a uniform coating film with high precision, which is excellent in appearance and scratch resistance. As a result, (i) the ratio (Vr / Vf) of the rotational speed (Vr) of the gravure roll to the conveyance speed (Vf) of the base material film is set within a specific range, and (ii) by setting the amount of water vapor in the coating process within a specific range, it has been found that a uniform coating film can be formed and a coating film excellent in appearance and scratch resistance can be formed, leading to the embodiments of the present invention.

[0025] In the high-speed gravure coating as in the above (i), the contact portion between the base material film and the gravure roll is charged with static electricity and the beads are disturbed. In the present embodiment, the technical significance of adjusting the amount of water vapor in the coating process lies in suppressing such disturbance of the beads. That is, in the present embodiment, with the high-speed gravure coating as in the above (i), in order to suppress the disturbance of the bead portion, it has become necessary to adjust the amount of water vapor in the coating process for the first time.

[0026] 〔One Embodiment of the Present Invention〕 Hereinafter, one embodiment of the present invention will be described in detail.

[0027] <Method for Manufacturing a Laminated Film According to the Present Embodiment> The method for manufacturing a laminated film according to the present embodiment (hereinafter sometimes referred to as the present manufacturing method) has a coating step of forming a coating film by applying a coating liquid onto a base film using a gravure roll, and at least (i) in the coating step, the ratio (Vr / Vf) of the rotational speed (Vr) of the gravure roll to the conveyance speed (Vf) of the base film is 30 to 60, and (ii) the amount of water vapor in the coating step is 10 to 25 g / m 3 is.

[0028] (Base film) The base film used in the present manufacturing method is a film or sheet-like base material having a uniform thickness and flexibility, formed into a long strip shape. The material constituting the base material is not particularly limited, and examples thereof include resins, paper, cloth, metals, etc., and can be appropriately selected according to the application. When the material constituting the base film is a resin, specifically, polyolefin resins such as polyethylene, polypropylene, and polycyclic olefins; acrylic resins; cellulose resins; polyamide resins such as nylon 6 and nylon 6,6; polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polycarbonate; polyimide; mixtures of these resins, etc. can be mentioned. When the application of the laminated film is a display such as a smartphone, among these resins, the material of the base film is preferably a polyimide resin.

[0029] (Coating step) The coating step in the present manufacturing method may be any step of forming a coating film by applying a coating liquid onto a base film using a gravure roll. More specifically, in the coating step, while continuously conveying the strip-shaped base film by a conveyance roll, the surface of the base film is continuously coated with the coating liquid using a gravure roll. The gravure roll is a rotating body that rotates while adhering (holding) the coating liquid on its peripheral surface. When the gravure roll contacts the surface of the base film, the coating liquid adhering to the gravure roll transfers to the surface of the base film.

[0030] FIG. 1 is a cross-sectional view showing an example of the configuration of a coating apparatus used in the coating step of the present manufacturing method.

[0031] As shown in FIG. 1, the coating apparatus 10 includes conveyance rolls F1 and F2, a coating liquid tank H, a gravure roll 3, pressing rolls 5A and 5B, and a blade 6. Further, in the coating apparatus 10, at least a chamber 7 that houses the gravure roll 3 and the base material film 1 that contacts the gravure roll 3 is provided. The chamber 7 constitutes the coating section in the coating apparatus 10.

[0032] The gravure roll 3 has a rotating shaft 3A and is a rotating body that rotates in contact with the coating liquid 2 in the coating liquid tank H. Further, the rotating directions of the gravure roll 3 and the conveyance rolls F1 and F2 are different from each other. That is, the gravure roll 3 rotates reversely with respect to the conveyance direction of the base material film 1 by the conveyance rolls F1 and F2. Further, fine liquid reservoir recesses are formed on the surface of the gravure roll 3. In the coating apparatus 10, the coating liquid 2 is transferred from the gravure roll 3 to the base material film 1 continuously conveyed by the conveyance rolls F1 and F2, and a coating film 4 is formed on the back surface of the base material film 1. The width of the gravure roll 3 is larger than the width of the base material film 1. Therefore, the gravure roll 3 contacts the entire width of the base material film 1. Therefore, the coating liquid 2 can be transferred to the entire width of the base material film 1 by the gravure roll 3.

[0033] The pressing rolls 5A and 5B are configured to press the back surface of the surface of the base material film 1 that contacts the gravure roll 3 toward the gravure roll 3 by adjusting their positions. The pressing rolls 5A and 5B maintain the contact state between the continuously conveyed base material film 1 and the gravure roll 3.

[0034] The blade 6 is arranged such that its tip faces the surface of the gravure roll 3 to which the coating liquid 2 adheres before being transferred to the base material film 1. The tip of the blade 6 is in contact with the surface of the gravure roll 3. Also, the width of the tip of the blade 6 is larger than the width of the base material film 1. By the tip of the blade 6 coming into contact with the coating liquid 2 adhering to the surface of the gravure roll 3 over a width equal to or greater than the width of the base material film 1, the thickness of the film of the coating liquid 2 on the surface of the gravure roll 3 can be made uniform.

[0035] Also, in the coating apparatus 10, water vapor is supplied into the chamber 7. By adjusting the amount of water vapor supplied to the chamber 7, the amount of water vapor in the coating process is adjusted.

[0036] In this manufacturing method, for example, the coating process can be carried out by operating the coating apparatus 10. In this coating process, while continuously conveying the strip-shaped base material film 1 by the conveying rolls F1 and F2, the surface of the base material film 1 is continuously coated with the coating liquid 2 by the gravure roll 3. Specifically, in this coating process, the following steps (i) to (iii) are continuously performed. Step (i) of supplying the coating liquid 2 from the coating liquid tank H to the gravure roll 3, adhering the coating liquid 2 to the surface of the gravure roll 3, and rotating the gravure roll 3. Step (ii) of making the thickness of the film of the coating liquid 2 uniform by bringing the coating liquid 2 adhering to the surface of the rotating gravure roll 3 into contact with the blade 6. Step (iii) of further rotating the gravure roll 3 and bringing it into contact with the base material film 1 to transfer the film of the coating liquid 2 with a uniform thickness in step (ii) to the base material film 1.

[0037] As described above, the contact state between the continuously conveyed base film 1 and the gravure roll 3 is maintained by the pressing rolls 5A and 5B. Therefore, by performing the above steps (i) to (iii), the coating liquid 2 sandwiched between the base film 1 and the gravure roll 3 forms a bead portion 2A (liquid pool) while rotating between the base film 1 and the gravure roll 3, and maintains a stable state. By maintaining the bead portion 2A in a stable state in this way, a stable coating film 4 can be formed on the base film 1.

[0038] Note that the coating apparatus used in the coating process is not limited to the configuration shown in FIG. 1, and any configuration capable of coating using a gravure roll may be used. For example, in the coating process, the gravure roll and the conveying roll may rotate in the same direction. From the viewpoint of maintaining the bead portion in a stable state, it is preferable that the gravure roll and the conveying roll rotate in different directions from each other.

[0039] In this manufacturing method, in the coating process using the above-described coating apparatus, particularly the coating apparatus shown in FIG. 1, (i) the ratio (Vr / Vf) of the rotational speed (Vr) of the gravure roll to the conveying speed (Vf) of the base film is 30 to 60, and (ii) the amount of water vapor in the coating process is 10 to 25 g / m 3 is. The coating process is a high-speed gravure coating in which the gravure roll rotates at a higher speed than the conveying speed (Vf) of the base film. Also, the numerical range of the amount of water vapor corresponds to a humidity of about 70 to 80%.

[0040] By the Vr / Vf and the amount of water vapor being within the above numerical ranges, (a) the bead portion can be maintained in a stable state, and (b) a high shearing force can be applied to the coating liquid applied to the base film from the gravure roll rotating at a high speed. As a result, a uniform coating film can be formed, and a coating film excellent in appearance and scratch resistance can be formed.

[0041] In high-speed gravure coating that satisfies the numerical range of Vr / Vf, the contact portion between the substrate film and the gravure roll is charged by static electricity. And due to this charging, the bead portion becomes unstable and disturbed. Therefore, in order to suppress the disturbance of the bead portion caused by this charging, it is necessary to adjust the amount of water vapor in the coating process to the above numerical range. The method for adjusting the amount of water vapor in the coating process is not particularly limited. For example, when using the coating apparatus shown in FIG. 1, the amount of water vapor supplied to the chamber 7 is adjusted. Also, a known humidity control apparatus can be used for the apparatus for adjusting the amount of water vapor in the chamber 7, and it is not particularly limited. For example, the amount of water vapor can be suitably adjusted by controlling the humidity of the gas phase in the chamber by connecting a precision air conditioner to the coating apparatus.

[0042] Incidentally, the Vr / Vf is preferably 32 to 55, more preferably 34 to 50.

[0043] Also, in this manufacturing method, the rotational speed (Vr) of the gravure roll is 3 to 100 m / min, preferably 10 to 70 m / min, and more preferably 15 to 30 m / min. Also, the conveyance speed (Vf) of the substrate film is 0.1 to 10 m / min, preferably 0.3 to 5 m / min, and more preferably 0.5 to 2 m / min. By the rotational speed (Vr) of the gravure roll and the conveyance speed (Vf) of the substrate film being within the above numerical range, a high shearing force is applied to the coating film, and a highly precise uniform film excellent in appearance and characteristics can be continuously formed.

[0044] Also, the amount of water vapor is preferably 12 to 24 g / m 3 and more preferably 15 to 20 g / m 3 is.

[0045] (Drying process) This manufacturing method may include a drying step of drying the coating film formed in the coating step. For example, after transferring a coating liquid onto a substrate film using the coating apparatus shown in FIG. 1 to form a coating film, in the drying step, the solvent in the coating film is removed to dry and cure the coating film. The method for drying and curing the coating film in the drying step can adopt a known drying method used in the gravure coating technique as long as it can remove the solvent in the coating film and dry and cure the coating film.

[0046] (Coating liquid) The coating liquid used in this manufacturing method includes a solvent and a resin soluble in the solvent. The soluble resin is not particularly limited as long as it can form a coating film through drying, curing, etc. after being coated on the substrate film.

[0047] Examples of the resin used in the coating liquid include, specifically, polyurethane; polycycloolefin; polycarbonate; polyester; polyether ketone; polyamide; polyimide; fluororesin; mixtures of these resins, etc. In particular, examples of the fluororesin include perfluoroalkyl group-containing compounds having an alkoxysilyl group in the molecule, fluoroalkyl ether oligomers, etc. Further, when the coating film formed in the coating step is an anti-fingerprint layer, the coating liquid is preferably a fluorine-based coating liquid containing the above-mentioned fluororesin.

[0048] The solvent used in the coating liquid refers to those that can dissolve or disperse the resin. Therefore, in the coating liquid, the resin may be dissolved by the solvent or dispersed as a solid content. The solvent only needs to be able to dissolve or disperse the resin, and can be appropriately selected according to the resin and substrate film to be used. Examples of the solvent include halogenated hydrocarbons such as dichloromethane and dichloroethane; phenols such as phenol and p-chlorophenol; alcohols such as methanol and ethanol; aromatic hydrocarbons such as benzene and toluene; acetone; ethyl acetate; ethylene glycol monomethyl ether; diethylene glycol dimethyl ether; methyl isobutyl ketone; methyl ether ketone; cyclohexane; cyclopentanone; water; hydrofluoroether, etc. These solvents may be used alone or in an appropriate combination of two or more. In particular, when the coating liquid is a fluorine-based coating liquid, the solvent includes hydrofluoroether.

[0049] Also, the solid content concentration of the coating liquid is preferably 0.05 to 0.5%, and more preferably 0.1 to 0.3%. When the solid content concentration of the coating liquid is within the above numerical range, a large flow before drying after coating can be reduced, and a sufficient leveling effect before drying can be obtained.

[0050] Further, the viscosity of the coating liquid is preferably 0.1 to 100 mPa·s, more preferably 0.3 to 50 mPa·s, and even more preferably 0.5 to 20 mPa·s. Even if the viscosity of the coating liquid used is as low as within the above numerical range, in this manufacturing method, if a liquid component is interposed between the gravure roll and the substrate film, the coating liquid can be coated on the substrate film due to surface tension.

[0051] In addition, the film thickness of the coating film formed in the coating step is preferably 5 to 50 nm, more preferably 10 to 30 nm. When the film thickness of the coating film is within the above numerical range, a coating film with sufficient scratch resistance can be obtained without clouding of the appearance.

[0052] (Manufacturing Apparatus for Laminated Film) The manufacturing apparatus for the laminated film according to this embodiment (hereinafter, may also be referred to as this manufacturing apparatus) is configured to perform at least the coating step among the steps of the manufacturing method of the laminated film described above. That is, this manufacturing apparatus is an apparatus including a coating section having a gravure roll that applies a coating liquid onto a base film conveyed by a conveyance roll to form a coating film. And in this manufacturing apparatus, (i) the ratio (Vr / Vf) of the rotation speed (Vr) of the gravure roll to the conveyance speed (Vf) of the base film is set to be 30 to 60, and (ii) the amount of water vapor in the coating section is adjusted to 10 to 25 g / m 3 . For example, this manufacturing apparatus has a configuration including the coating apparatus 10 shown in FIG. 1. Note that this manufacturing apparatus appropriately applies the description of the manufacturing method described above.

Examples

[0053] Examples, comparative examples, and reference examples are given below, but the present invention is not limited thereto.

[0054] (1) Preparation of Polyamic Acid Solution 383 parts by weight of N,N-dimethylformamide (DMF) was charged into a reaction vessel and stirred under a nitrogen atmosphere. 31.8 parts by weight of 2,2'-bis(trifluoromethyl)benzidine and 10.5 parts by weight of 3,3'-diaminodiphenyl sulfone were added thereto, and the mixture was stirred under a nitrogen atmosphere to obtain a diamine solution. To the diamine solution, 15.9 parts by weight of p-phenylenebis(trimellitic anhydride), 37.4 parts by weight of 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, and 10.4 parts by weight of 3,3',4,4'-biphenyltetracarboxylic dianhydride were added, and the mixture was stirred under a nitrogen atmosphere to obtain a polyamic acid solution.

[0055] (2) Imidization and extraction of polyimide resin 38.4 parts by weight of pyridine was added as an imidization catalyst to the polyamic acid solution (100 parts by weight of the solid content of polyamic acid) obtained in (1), and the mixture was stirred. Then, 49.5 parts by weight of acetic anhydride was added, and the mixture was stirred at 120 °C for 2 hours and then cooled to room temperature to obtain a polyimide solution. While stirring the polyimide solution, 1 L of isopropyl alcohol was added dropwise to precipitate a polyimide resin. Then, the filtered polyimide resin was washed three times with isopropyl alcohol and then dried at 120 °C for 12 hours to obtain a powder of polyimide resin.

[0056] (3) Preparation of polyimide film The polyimide resin obtained in (2) was dissolved in methylene chloride to obtain a polyimide solution with a solid content concentration of 10%. Using a comma coater, the polyimide solution was applied onto a substrate and dried in an atmospheric pressure atmosphere in the order of 40 °C for 10 minutes, 80 °C for 10 minutes, 150 °C for 10 minutes, and 180 °C for 10 minutes, and then peeled off from the substrate to obtain a transparent polyimide film with a thickness of 50 μm.

[0057] (4) Preparation of hard coat composition 100 parts by weight of β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 0.12 parts by weight of magnesium chloride, 11 parts by weight of water and 11 parts by weight of propylene glycol monomethyl ether were charged into a reaction vessel, stirred at 130 °C for 3 hours, and then degassed under reduced pressure at 60 °C to obtain a siloxane resin. Then, 100 parts by weight of the siloxane resin, 2 parts by weight of a propylene carbonate solution of a triarylsulfonium·SbF 6 salt, 0.2 parts by weight of a xylene / isobutanol solution of polyether-modified polydimethylsiloxane, and 100 parts by weight of propylene glycol monomethyl ether were blended to obtain a hard coat composition.

[0058] (5) Preparation of a composition containing a perfluoroalkyl group-containing compound having an alkoxysilyl group in the molecule In the preparation, Solution I: a 20% solution of a fluoroalkyl ether oligomer having a trialkoxysilyl group in the molecule in hydrofluoroether (manufactured by Daikin Industries, Ltd.; OPTOOL UD509), and Solution II: hydrofluoroether (manufactured by 3M; Novec7200) were used. Specifically, Solution I was diluted with Solution II to obtain a composition containing a perfluoroalkyl group-containing compound having an alkoxysilyl group in the molecule with a solid content concentration of 0.1% (hereinafter sometimes referred to as Coating Liquid A). The viscosity of the composition was 0.6 mPa·s.

[0059] (Example 1) A hard coat composition was applied onto a 50-μm-thick transparent polyimide film as a transparent resin film layer using a die coater so that the dry film thickness became 20 μm, and heated to 120 °C to remove the solvent. Then, using a high-pressure mercury lamp, ultraviolet rays were irradiated so that the integrated light quantity became 1950 mJ / cm 2 to cure the hard coat composition and obtain a transparent resin film with a hard coat layer (hereinafter sometimes referred to as Substrate Film A).

[0060] Using a corona treatment machine, the surface of the hard coat layer of Substrate Film A was treated at a treatment density of 40 W·min / m 2After performing the corona treatment, a coating step was carried out in which the coating liquid A obtained in (5) was coated on the base film A. In this coating step, using the coating apparatus 10 shown in FIG. 1, the coating liquid A was coated on the base film A under the following conditions to form a coating film with a film thickness of 10 nm. (i) The ratio (Vr / Vf) of the rotation speed (Vr) of the gravure roll 3 to the conveyance speed (Vf) of the base film A was set to 34. (ii) The amount of water vapor in the chamber 7 constituting the coating section was 17.3 g / m 3 2. Also, the conveyance speed (Vf) of the base film A was set to 0.5 m / min.

[0061] After the coating step, the solvent in the coating film of the coating liquid A formed on the base film A was removed at 130°C to obtain a hard coat film with a fingerprint-resistant layer. In this hard coat film, a fingerprint-resistant layer was laminated as a coating film on the hard coat layer of the base film A.

[0062] (Examples 2, 3 and Comparative Examples 1 to 7) A hard coat film with a fingerprint-resistant layer was obtained in the same manner as in Example 1, except that the values of Vf and Vr were adjusted so that Vr / Vf was 1.4 to 67. The Vr / Vf values set in Examples 2, 3 and Comparative Examples 1 to 7 are as shown in Table 1. Also, for Vf, it was set to 0.5 m / min in Example 2, 2.0 m / min in Example 3, 0.5 m / min in Comparative Examples 1 to 4, and 2.0 m / min in Comparative Examples 5 to 7.

[0063] (Examples 4, 5 and Comparative Examples 8 to 10) A hard coat film with a fingerprint-resistant layer was obtained in the same manner as in Example 1, except that the amount of water vapor in the chamber 7 was adjusted to 3.85 to 27.3 g / m 3 2. The amounts of water vapor set in Examples 4, 5 and Comparative Examples 8 to 10 are as shown in Table 1. Also, for Vf, it was set to 0.5 m / min in Examples 4, 5 and Comparative Examples 8 to 10.

[0064] The evaluation criteria for the hard coat films with a fingerprint-resistant layer obtained in Examples 1 to 5 and Comparative Examples 1 to 10 are as follows.

[0065] <Appearance> The appearance of the obtained hard coat film with a fingerprint-resistant layer was evaluated visually by reflection and projection using a light source. Those maintaining the same appearance as before the formation of the fingerprint-resistant layer were rated as ○, and those showing clouding were rated as ×.

[0066] <Scratches after the abrasion resistance test> A 6-mm diameter eraser made by Minoan was set as a indenter, and the abrasion resistance test of the fingerprint-resistant layer side surface of the hard coat film with a fingerprint-resistant layer was carried out using a reciprocating wear tester (manufactured by Shin-Toyo Kagaku Co., Ltd., TYPE: 30S) under the conditions of a 50-mm stroke and 1 cycle / second. The load was 500 g and the number of cycles was 1500. The samples after the abrasion resistance test were visually inspected. Those with no scratches or scratches less than 2 mm in length on the tested surface were rated as ○, those with scratches 2 mm or more in length were rated as △, and those with scratches continuously across the entire width were rated as ×.

[0067] <Contact angle after the abrasion resistance test> Using a contact angle meter PCA-11 manufactured by Kyowa Interface Science Co., Ltd., the water contact angle of the sample after the abrasion resistance test was measured. Pure water was used for the measurement, and the droplet volume was 2 μL. Those with a contact angle of 100° or more were rated as ○, those with a contact angle of 90° or more and less than 100° were rated as △, and those with a contact angle of less than 90° were rated as ×.

[0068] The evaluation results of Examples 1 to 5 and Comparative Examples 1 to 10 are shown in Table 1.

[0069]

Table 1

[0070] From the evaluation results shown in Table 1, it was confirmed that when Vr / Vf is within a certain range and the amount of water vapor in the coating section (chamber 7) is within a certain range, the appearance of the hard coat film with a fingerprint-resistant layer obtained is good and the abrasion resistance is also good. When the amount of water vapor is large as in Comparative Example 10, it is presumed that the silanol groups of the resin component of the coating liquid react with moisture, resulting in poor appearance.

Explanation of Symbols

[0071] 1 Base film 2 Coating liquid 3 Gravure roll 4 Coating film 7 Chamber (coating section) F1 Conveyor roll F2 Conveyor roll

Claims

1. It has a coating step of forming a coating film by applying a coating liquid onto a base film using a gravure roll, in the coating step, the ratio (Vr / Vf) of the rotational speed (Vr [unit: m / min]) of the gravure roll to the conveyance speed (Vf [unit: m / min]) of the base film is 30 to 60, The amount of water vapor in the coating process is 10 to 25 g / m ３ , which is a method for manufacturing a laminated film.

2. The method for manufacturing a laminated film according to claim 1, wherein the rotational directions of the gravure roll and the conveyance roll of the base film are different from each other.

3. The method for manufacturing a laminated film according to claim 1 or 2, including a drying step of drying the coating film formed in the coating step.

4. The coating liquid contains a solvent and a resin soluble in the solvent, The method for manufacturing a laminated film according to any one of claims 1 to 3, wherein the solid content concentration of the coating liquid is 0.05 to 0.5%, the viscosity of the coating liquid is 0.1 to 100 mPa·s, and the film thickness of the coating film is 10 to 50 nm.

5. The method for manufacturing a laminated film according to any one of claims 1 to 4, wherein the coating liquid is a fluorine-based coating liquid.

6. The method for manufacturing a laminated film according to any one of claims 1 to 5, wherein the coating film is an anti-fingerprint layer.

7. A manufacturing apparatus for a laminated film, comprising a coating section provided with a gravure roll for applying a coating liquid onto a base film conveyed by a conveyance roll to form a coating film, The ratio (Vr / Vf) of the rotational speed (Vr [unit: m / min]) of the gravure roll to the conveyance speed (Vf [unit: m / min]) of the base film is set to be 30 to 60. The amount of water vapor in the coating section is adjusted to 10 to 25 g / m ３ Manufacturing apparatus for a laminated film.

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