Film, multilayer body, and transparent conductive film

Abstract

To provide a film which is excellent in slidability and windability, and is transparent, a multilayer body, and a transparent conductive film.SOLUTION: A film is provided, including 0.01-0.45 pts.mass of organic particle having a number average particle diameter of 2.6-4.8 μm with respect to 100 pts.mass of a polycarbonate resin and having a refractive index of 1.55-1.63, the film has a thickness of 20 μm or more and less than 500 μm.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a film, a multilayer body, and a transparent conductive film. [Background technology]

[0002] Transparent conductive films are used in film sensors of touch panels, electronic paper, dye-sensitized solar cells, touch sensors, etc. As shown in Fig. 1, for example, a transparent conductive film 10 is known that is composed of an electrode layer (transparent conductive film) 11, a substrate 12, an adhesive layer 13, and a protective film 14. Specifically, Patent Document 1 discloses a transparent conductive film laminate having, in this order, an adhesive layer, a film substrate, and a transparent conductive film on a protective film, wherein at least one of the film substrate and the protective film has an uneven surface on the adhesive layer side in each end region from one end to the other end in the width direction, the uneven surface in each end region extending 100 mm inward in the width direction, the effective roughness R1 of the uneven surface in each end region being 0.1 to 20 μm, and the adhesive layer is provided in the width direction from a position where the distance between the uneven surface in one end region and the uneven surface in the other end region is 0 to 10 mm to a position where the distance between the uneven surface in the one end region and the uneven surface in the other end region is 0 to 10 mm. It also discloses that the protective film is made of a polycarbonate resin. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-152187 Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, a protective film is typically used for transparent conductive films. Such a protective film is used to protect the substrate when a multilayer structure having an electrode layer and a substrate is transported. More specifically, transparent conductive films are often produced industrially using a roll-to-roll process, which requires improved film transportability and prevention of winding wrinkles. Film transport problems and winding wrinkles can be reduced by suppressing adhesion (blocking) between films. Therefore, to provide anti-blocking on the side opposite the electrode layer of a transparent conductive film, the protective film for the transparent conductive film is required to have sufficient sliding properties to prevent films from stacking and to prevent transport problems and winding wrinkles. Furthermore, transparent conductive films are typically subjected to in-line defect inspection with the protective film attached, so they are required to be transparent. The present invention aims to solve the above problems, and to provide a transparent film, a multilayer body, and a transparent conductive film that are excellent in slidability and windability. [Means for solving the problem]

[0005] In view of the above problems, the present inventors have conducted research and have found that the above problems can be solved by using specific particles for imparting irregularities to the surface of a film. Specifically, the above problems were solved by the following means. <1> A film having a thickness of 20 μm or more and less than 500 μm, which contains 0.01 to 0.45 parts by mass of organic particles having a number average particle diameter of 2.6 to 4.8 μm and a refractive index of 1.55 to 1.63 per 100 parts by mass of polycarbonate resin. <2> The total light transmittance of the film under the condition of a D65 light source and a 10° field of view is 86.0% or more. <1> The film according to claim 1. <3> The haze of the film under a D65 light source and a 10° viewing angle condition is less than 2.0%. <1> or <2> The film according to claim 1. <4> The number average particle diameter of the organic particles is 3.0 to 4.0 μm. <1> ~ <3> 10. The film according to any one of the preceding items. <5> The content of the organic particles is 0.01 to 0.40 parts by mass relative to 100 parts by mass of the polycarbonate resin. <1> ~ <4> 10. The film according to any one of the preceding items. <6> At least one surface of the film has a dynamic friction coefficient of 1.00 or less against a film having a root mean square roughness of 0.093 μm. <1> ~ <5> 10. The film according to any one of the preceding items. <7> the organic particles contain styrene; <1> ~ <6> 10. The film according to any one of the preceding items. <8> The organic particles are rubber-free. <1> ~ <7> 10. The film according to any one of the preceding items. <9> It is a single layer film, <1> ~ <8> 10. The film according to any one of the preceding items. <10> <1> ~ <9> A multilayer body comprising the film according to any one of the above and at least one other layer. <11> The other layer includes an adhesive layer. <10> The multilayer body according to claim 1. <12> A transparent conductive film having a protective layer, an adhesive layer, a substrate, and an electrode layer in this order, wherein at least one of the substrate and the protective layer is <1> ~ <9> A transparent conductive film, which is the film according to any one of the above items. [Effects of the Invention]

[0006] The present invention makes it possible to provide a transparent film, a multilayer body, and a transparent conductive film that are excellent in slidability and windability. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of the layer structure of a transparent conductive film. [Figure 2] Figure 2(a) is a schematic diagram showing a state in which a smooth polycarbonate resin film is slid over another smooth polycarbonate resin film, and Figure 2(b) is a schematic diagram showing a state in which a polycarbonate resin film with a finely textured surface is slid over a polycarbonate resin film with a finely textured surface. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. Note that the present embodiment is an example for explaining the present invention, and the present invention is not limited to only this embodiment. In this specification, the symbol "to" is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit. In this specification, various physical properties and characteristic values ​​are those at 23°C unless otherwise specified. The term "film" as used herein refers to a generally flat shaped body that is thin relative to its length and width, and includes a sheet. The term "film" as used herein may be either a single layer or a multilayer. If the standards shown in this specification differ depending on the year and the measurement method, etc., they will be based on the standards as of January 1, 2021, unless otherwise stated.

[0009] The film of this embodiment is characterized by containing 0.01 to 0.45 parts by mass of organic particles having a number average particle diameter of 2.6 to 4.8 μm and a refractive index of 1.55 to 1.63 per 100 parts by mass of polycarbonate resin, and having a thickness of 20 μm or more and less than 500 μm. This configuration makes it possible to provide a transparent film that is excellent in slidability and windability, and in particular, allows for good appearance when wound up without a masking film.

[0010] To improve film transportability and prevent wrinkles during film wrapping, films may be required to have sufficient sliding properties to prevent stacking and even prevent adhesion between films (anti-blocking properties). Here, anti-blocking refers to the ability to easily peel films even when they are in close contact with each other. Figure 2(a) is a schematic diagram showing a smooth film sliding on another smooth film. Placing a smooth film on top of another smooth film like this results in no sliding. To impart sliding properties to a smooth film, it is possible to provide fine irregularities on the film surface, as shown in the schematic diagram in Figure 2(b). Providing fine irregularities on the film surface reduces the contact area between the films, achieving high sliding properties. In Figure 2, 21 denotes a film with a smooth surface, and 22 denotes a film with a fine irregularity on its surface. Although Figure 2 shows two films with fine irregularities, as shown in the examples below, sliding properties are generally achieved if at least one of the films has fine irregularities.

[0011] In order to provide irregularities on the surface of such films to ensure sliding properties, it is conceivable to incorporate particles into the thermoplastic resin. However, incorporating particles into the thermoplastic resin may result in poor transparency. Furthermore, it has been found that depending on the size and type of particles and the thickness of the film, it may not be possible to successfully form irregularities on the film surface. In this embodiment, the particle size, material, refractive index, and blending amount of the particles are precisely adjusted, and the thickness of the film is also adjusted, thereby solving the above problem. The details of this embodiment will be described below.

[0012] <Polycarbonate resin> The film of the present embodiment contains a polycarbonate resin. By using a polycarbonate resin, a film with excellent transparency can be obtained. The polycarbonate resin used in this embodiment is not particularly limited as long as it contains an -[OR-OC(=O)]- unit (where R is a hydrocarbon group, specifically an aliphatic group, an aromatic group, or one containing both an aliphatic group and an aromatic group, and further one having a linear or branched structure) containing a carbonate bond in the molecular main chain. In this embodiment, the polycarbonate resin is preferably an aromatic polycarbonate resin, and more preferably a polycarbonate resin having a bisphenol skeleton. The use of such a polycarbonate resin achieves better heat resistance and toughness. In this embodiment, the polycarbonate resin having a bisphenol skeleton preferably contains 90 mol % or more of all structural units of the polycarbonate resin having a bisphenol skeleton.

[0013] The viscosity average molecular weight (Mv) of the polycarbonate resin is preferably 10,000 or more, more preferably 12,000 or more, even more preferably 15,000 or more, and even more preferably 18,000 or more. By setting it to be equal to or greater than the lower limit, the durability of the substrate tends to be further improved. The upper limit of the viscosity average molecular weight (Mv) of the polycarbonate resin is preferably 50,000 or less, more preferably 40,000 or less, and even more preferably 30,000 or less. By setting it to be equal to or less than the upper limit, the moldability of the substrate tends to be further improved. The viscosity average molecular weight (Mv) was calculated by using methylene chloride as a solvent and an Ubbelohde viscometer to determine the intrinsic viscosity [η] (unit: dL / g) at 25°C, and then using the Schnell viscosity formula, i.e., η = 1.23 × 10 -4 ×Mv 0.83 , means the value calculated from When two or more types of polycarbonate resins are used, the viscosity average molecular weight is the viscosity average molecular weight of the mixture.

[0014] The refractive index of the polycarbonate resin is preferably 1.56 or more, more preferably 1.58 or more, and preferably 1.63 or less, more preferably 1.60 or less. By setting the refractive index at or above the lower limit, the difference in refractive index with the organic particles becomes small, and transparency tends to be improved. By setting the refractive index at or below the upper limit, the difference in refractive index with the organic particles becomes small, and transparency tends to be improved. The difference in refractive index between the polycarbonate resin and the organic particles is preferably 0.1 or less, and more preferably 0.04 or less. By reducing the difference in refractive index, the transparency of the film of the present embodiment can be further improved.

[0015] The polycarbonate resin content in the film of this embodiment is preferably 95% by mass or more, more preferably 97% by mass or more, and may be 99% by mass or more of the entire film. The upper limit of the polycarbonate resin content is the value at which the total of the polycarbonate resin and the organic particles accounts for 100% by mass of the entire film. The film of the present embodiment may contain only one type of polycarbonate resin, or may contain two or more types. When two or more types are contained, the total amount is preferably within the above range.

[0016] A first embodiment of the polycarbonate resin in this embodiment is a polycarbonate resin having a structural unit represented by formula (A-1), and a representative example thereof is a bisphenol A polycarbonate resin. [ka] In formula (A-1), X 1 represents the following structure: * in the formula represents the bonding position. [ka] R 5 and R 6 At least one of the groups is preferably a methyl group, and both are more preferably methyl groups. Formula (A-1) is preferably represented by the following formula (A-2). [ka]

[0017] In the polycarbonate resin of the first embodiment, the content of the structural unit represented by formula (A-1) is preferably 70 mol% or more, more preferably 80 mol% or more, and even more preferably 90 mol% or more, of all structural units excluding terminal groups. There is no particular upper limit, and 100 mol% may be structural units represented by formula (A-1). The polycarbonate resin may have other structural units. Examples of dihydroxy compounds constituting such other structural units include the aromatic dihydroxy compounds described in paragraph 0014 of JP 2018-154819 A, the contents of which are incorporated herein by reference.

[0018] A second embodiment of the polycarbonate resin in this embodiment is a polycarbonate resin containing a structural unit represented by formula (A-3), and a representative example thereof is a bisphenol AP type polycarbonate resin. [ka] In formula (A-3), R 11 ~R 14 each independently represents a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 9 carbon atoms (preferably 1 to 3), an aryl group having 6 to 12 carbon atoms (preferably 6 to 10), an alkoxy group having 1 to 5 carbon atoms (preferably 1 to 3), an alkenyl group having 2 to 5 carbon atoms (preferably 2 or 3), or an aralkyl group having 7 to 17 carbon atoms (preferably 7 to 11). 1 represents an integer of 0 to 5 (preferably 0 or 1, more preferably 0). m and n each independently represent an integer of 0 to 4 (preferably 0 or 1, more preferably 0). * in the formula represents the bonding position to other structural units or terminal groups.

[0019] The structural unit represented by formula (A-3) is preferably a structural unit represented by the following formula (A-4): In the formula, * indicates the bonding position to other structural units or terminal groups. [ka] R 11 , R 12 , R 13 , R 14 , l, m, and n are the same as defined in formula (A-3).

[0020] The structural unit represented by formula (A-4) is preferably a structural unit represented by the following formula (A-5): In the formula, * indicates the bonding position to other structural units or terminal groups. [ka]

[0021] In the polycarbonate resin of the second embodiment, the content of the structural unit represented by formula (A-3) is preferably 70 mol% or more, more preferably 80 mol% or more, and even more preferably 90 mol% or more, of all structural units excluding terminal groups. There is no particular upper limit, and 100 mol% may be structural units represented by formula (A-3). The polycarbonate resin may have other structural units, such as the structural unit represented by formula (A-1) and the structural unit derived from an aromatic dihydroxy compound described in paragraph 0014 of JP-A-2018-154819, the contents of which are incorporated herein by reference.

[0022] A third embodiment of the polycarbonate resin in this embodiment is a polycarbonate resin having a structural unit represented by the following formula (A-6), and representative examples include bisphenol Z type polycarbonate resin and bisphenol TMC type polycarbonate resin. [ka] In formula (A-6), R 8each independently represents a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 9 carbon atoms (preferably 1 to 3), an aryl group having 6 to 12 carbon atoms (preferably 6 to 10), an alkoxy group having 1 to 5 carbon atoms (preferably 1 to 3), an alkenyl group having 2 to 5 carbon atoms (preferably 2 or 3), or an aralkyl group having 7 to 17 carbon atoms (preferably 7 to 11). q represents an integer of 0 to 5 (preferably an integer of 1 to 3), with an integer of 1 or 3 being preferred. * in the formula represents the bonding position to other structural units or terminal groups. R 8 are each independently preferably an alkyl group having 1 to 9 carbon atoms (more preferably 1 to 3 carbon atoms), more preferably a methyl group.

[0023] The structural unit represented by formula (A-6) is preferably a structural unit represented by the following formula (A-7): In the formula, * represents the bonding position to other structural units or terminal groups. [ka] In formula (A-7), R 8 is R in formula (A-6) 8 The same applies to the preferred range. Another preferred embodiment of the constitutional unit represented by formula (A-6) is one in which q is 0.

[0024] In the polycarbonate resin of the third embodiment, the content of the structural unit represented by formula (A-6) is preferably 70 mol% or more, more preferably 80 mol% or more, and even more preferably 90 mol% or more, of all structural units excluding terminal groups. There is no particular upper limit, and 100 mol% may be structural units represented by formula (A-6). The polycarbonate resin may have other structural units, such as the structural unit represented by the formula (A-1) above, the structural unit represented by the formula (A-3) above, and the structural unit derived from an aromatic dihydroxy compound described in paragraph 0014 of JP-A-2018-154819, the contents of which are incorporated herein by reference.

[0025] A fourth embodiment of the polycarbonate resin in this embodiment is a polycarbonate resin having a terminal structure represented by formula (A-8). [ka] (In formula (A-8), R 21 represents an alkyl group having 8 to 36 carbon atoms or an alkenyl group having 8 to 36 carbon atoms, and R 22 represents a halogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and n2 is an integer of 0 to 4.

[0026] R 21 is preferably an alkyl or alkenyl group having 12 or more carbon atoms, and more preferably an alkyl or alkenyl group having 14 or more carbon atoms. 21 R is preferably an alkyl or alkenyl group having 22 or less carbon atoms, and more preferably an alkyl or alkenyl group having 18 or less carbon atoms. 21 is preferably an alkyl group. R 22 is preferably a fluorine atom, a chlorine atom, a methyl group, an ethyl group, or a phenyl group, and more preferably a fluorine atom, a chlorine atom, or a methyl group. n2 is preferably an integer of 0 to 2, more preferably 0 or 1, and even more preferably 0.

[0027] The terminal structure represented by formula (A-8) can be added to a polycarbonate resin by using a terminal terminator. For details, see paragraphs 0022 to 0030 of JP 2019-2023 A, the contents of which are incorporated herein by reference.

[0028] The molecular main chain of the polycarbonate resin of the fourth embodiment is not particularly limited as long as it contains an -[OR-OC(=O)]- unit (wherein R is a hydrocarbon group, specifically an aliphatic group, an aromatic group, or one containing both an aliphatic group and an aromatic group, and further one having a linear or branched structure). The polycarbonate resin of the fourth embodiment is preferably an aromatic polycarbonate resin, more preferably a polycarbonate resin having a bisphenol skeleton, even more preferably a polycarbonate resin having a structural unit represented by the above formula (A-1), and even more preferably a bisphenol A polycarbonate resin. The use of such a polycarbonate resin achieves better heat resistance and toughness. In the polycarbonate resin having a bisphenol skeleton, it is preferable that 90 mol % or more of all structural units excluding terminal structures are structural units having a bisphenol skeleton.

[0029] The method for producing the polycarbonate resin is not particularly limited, and any method can be used, including, for example, interfacial polymerization, melt transesterification, pyridine method, ring-opening polymerization of a cyclic carbonate compound, and solid-phase transesterification of a prepolymer.

[0030] <Organic particles> The film of this embodiment contains organic particles having a number average particle size of 2.6 to 4.8 μm and a refractive index of 1.55 to 1.63 in an amount of 0.01 to 0.45 parts by mass per 100 parts by mass of polycarbonate resin. This configuration makes it possible to achieve good sliding properties and winding properties while maintaining the high transparency inherent to polycarbonate resin.

[0031] The number average particle diameter of the organic particles is 2.6 to 4.8 μm. By setting the number average particle diameter to be equal to or greater than the lower limit, the organic particles are more likely to be exposed to the surface, which tends to further improve the sliding properties of the film. On the other hand, by setting the number average particle diameter to be equal to or less than the upper limit, the transparency of the film tends to further improve. The number average particle size is preferably 2.8 μm or more, more preferably 3.0 μm or more. The number average particle size is preferably 4.5 μm or less, more preferably 4.0 μm or less, and even more preferably 3.8 μm or less. As the number average particle size increases, the number of organic particles contained decreases when compared with the same blending amount, resulting in an insufficient number of irregularities and poor sliding properties. When the film of the present embodiment contains two or more types of organic particles, the number average particle size is the number average particle size of the mixture of organic particles.

[0032] The organic particles have a refractive index of 1.55 to 1.63. By setting the refractive index at or above the lower limit, the refractive index approaches that of polycarbonate resin, and the transparency of the resulting film tends to be improved. By setting the refractive index at or below the upper limit, the refractive index approaches that of polycarbonate resin, and the transparency of the resulting film tends to be improved. The refractive index is preferably 1.56 or more, more preferably 1.57 or more, even more preferably 1.58 or more, and even more preferably 1.59 or more, and is preferably 1.62 or less, more preferably 1.61 or less, and even more preferably 1.60 or less. When the film of the present embodiment contains two or more types of organic particles, the refractive index of each type of organic particle must satisfy the above range.

[0033] Organic particles are particles that contain organic matter. The organic particles are preferably rubber-free particles. "Rubber-free" means, for example, that the rubber component of the particles is less than 1.0% by mass, preferably 0.5% by mass or less, more preferably 0.1% by mass or less, even more preferably 0.05% by mass or less, and even more preferably 0.01% by mass or less. Examples of rubber components include diene rubbers such as polybutadiene and acrylic rubbers such as polybutyl acrylate. By not including rubber, the hardness of the organic particles is increased, allowing appropriate irregularities to be formed on the surface of the film. On the other hand, it is difficult to impart appropriate irregularities to the surface of the film with elastomers such as butadiene styrene rubber, and the desired sliding properties cannot be achieved. When the film of this embodiment contains two or more types of organic particles, the amount of rubber component is defined as the total amount of rubber component relative to the total amount of organic particles. Furthermore, the organic particles preferably contain styrene. By containing styrene, the refractive index of the organic particles becomes closer to that of polycarbonate resin, and the transparency of the obtained film can be further improved. When the organic particles contain styrene, it is sufficient that at least 50% by area of ​​the surface layer of the organic particles is styrene.

[0034] The content of the organic particles is 0.01 to 0.45 parts by mass relative to 100 parts by mass of the polycarbonate resin. By making the content equal to or greater than the lower limit, sliding properties can be achieved. On the other hand, by making the content equal to or less than the upper limit, the transparency of the film, particularly the haze, can be improved. The content of the organic particles is preferably 0.02 parts by mass or more, more preferably 0.03 parts by mass or more, and even more preferably 0.04 parts by mass or more, relative to 100 parts by mass of the polycarbonate resin. The content of the organic particles is preferably 0.40 parts by mass or less, more preferably 0.30 parts by mass or less, even more preferably 0.20 parts by mass or less, even more preferably 0.12 parts by mass or less, even more preferably 0.10 parts by mass or less, and even more preferably 0.08 parts by mass or less, relative to 100 parts by mass of the polycarbonate resin. The film of the present embodiment may contain only one type of organic particle, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0035] The film of the present embodiment preferably does not substantially contain particles other than the organic particles (e.g., inorganic particles). "Substantially does not contain particles other than organic particles" means that the content of particles other than the organic particles is 10% by mass or less of the content of the organic particles used in the present embodiment, preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 1% by mass or less, and even more preferably 0.1% by mass or less.

[0036] <Release agent> The film of the present embodiment preferably contains a release agent. The release agent may be at least one compound selected from the group consisting of aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds having a number average molecular weight of 200 to 15,000, and polysiloxane-based silicone oils, and is preferably an ester of aliphatic carboxylic acids and alcohols. Specific examples of esters of aliphatic carboxylic acids and alcohols include beeswax (a mixture containing myricyl palmitate as a main component), stearyl stearate, behenyl behenate, stearyl behenate, glycerin monopalmitate, glycerin monostearate, glycerin distearate, glycerin tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, and pentaerythritol tetrastearate. Other examples of the release agent that can be used include the release agents described in paragraph 0032 of JP-A No. 2017-226848 and paragraph 0056 of JP-A No. 2018-199745, the contents of which are incorporated herein by reference.

[0037] When a release agent is contained in the film, the content of the release agent is preferably 0.001 part by mass or more, more preferably 0.005 part by mass or more, and preferably 2 parts by mass or less, more preferably 1 part by mass or less, and even more preferably 0.5 parts by mass or less, relative to 100 parts by mass of the polycarbonate resin. The release agent may be used alone or in combination of two or more. When two or more types are used, the total amount is preferably within the above range.

[0038] <Other ingredients> In addition to the polycarbonate resin, the film of this embodiment may contain other components within the scope of the present invention. Specifically, the film may contain antioxidants, transesterification inhibitors, heat stabilizers, flame retardants, flame retardant assistants, ultraviolet absorbers, colorants, antistatic agents, fluorescent brighteners, antifogging agents, flow improvers, plasticizers, dispersants, antibacterial agents, antiblocking agents, impact improvers, sliding improvers, color improvers, acid trapping agents, etc. These components may be used alone or in combination of two or more. The film of the present embodiment may be configured to be substantially free of resin components other than polycarbonate resin, meaning that the content of resin components other than polycarbonate resin is less than 1 part by mass per 100 parts by mass of the resin components contained in the film of the present embodiment. The film of the present embodiment may be configured to be substantially free of ultraviolet absorbers, meaning that the content of ultraviolet absorbers contained in the film of the present embodiment is less than 0.05 parts by mass per 100 parts by mass of the resin component.

[0039] For details about the antioxidant, please refer to paragraphs 0057 to 0061 of JP 2017-031313 A, the contents of which are incorporated herein by reference. For details of the transesterification inhibitor, please refer to paragraphs 0035 to 0039 of WO 2015 / 190162, paragraph 0037 of JP-A 2019-002023, and paragraph 0041 of JP-A 2018-199745, the contents of which are incorporated herein by reference.

[0040] <Film characteristics> The film of this embodiment has a thickness of 20 μm or more and less than 500 μm. By making the thickness less than 500 μm, the organic particles are more likely to be exposed on the surface, achieving slidability. In addition, the transparency of the film can be increased. Furthermore, the winding properties of the film can be improved. Furthermore, by making the thickness 20 μm or more, the haze can be further reduced and transparency tends to be improved. The thickness of the film of this embodiment may be 30 μm or more, or even 40 μm or more, and is preferably 400 μm or less, more preferably 300 μm or less, even more preferably 200 μm or less, still more preferably 100 μm or less, even more preferably 80 μm or less, and even more preferably 60 μm or less. The film thickness is the average value of five arbitrary points.

[0041] In the film of this embodiment, the coefficient of dynamic friction of at least one surface against a film having a root-mean-square roughness of 0.093 μm is preferably 1.00 or less, more preferably 0.90 or less, more preferably 0.80 or less, even more preferably 0.75 or less, and may be 0.74 or less. The lower limit is not particularly specified, but may be, for example, 0.10 or more, or even 0.20 or more, 0.30 or more, 0.40 or more, or 0.50 or more. The dynamic friction coefficient is a value measured under conditions of a thread speed of 100 mm / min and a load cell of 10 N, and specifically, is measured by the method described in the examples below.

[0042] The film of this embodiment preferably has a total light transmittance of 86.0% or more, more preferably 87.0% or more, and even more preferably 89.0% or more under the condition of a D65 light source and a 10° field of view. The upper limit of the light transmittance is ideally 100%, but even if it is 95.0% or less, the required performance is sufficiently met. The total light transmittance is measured by the method described in the examples below.

[0043] The film of this embodiment preferably has a haze of less than 2.0%, more preferably 1.8% or less, and may be 1.5% or less, or even 1.0% or less, under the condition of a D65 light source and a 10° field of view. The lower limit is ideally 0%, but even 0.1% or more is practical. It is particularly preferable that the haze be in the above range when the thickness is 20 μm to 100 μm. The haze is measured by the method described in the examples below.

[0044] <Method of manufacturing resin film> The film of this embodiment can be produced by a known production method. For example, the polycarbonate resin, organic particles, and other components, if necessary, can be melt-kneaded and then extruded into a film. Furthermore, roll-to-roll production is preferred.

[0045] <Wound body> The film of this embodiment can be wound around a core material to form a roll. For example, the film of this embodiment can be wound to a length of 30 m or more onto a cardboard tube with an inner diameter of 3 inches without using a masking film, by controlling the take-up tension to 200 N.

[0046] <Application> The film of the present embodiment may be a single-layer film or a multi-layer film composed of multiple resin layers, but is preferably a single-layer film, which makes it easy to properly expose the organic particles on the film surface. The film of this embodiment can be used as a multilayer body including the film (preferably a monolayer film) and at least one other layer. By producing a monolayer film and then laminating another layer, the surface irregularities of the film can be appropriately maintained. A known layer can be used as the other layer, such as an adhesive layer. That is, an example of a use of the film of this embodiment is a bonding adhesive sheet having the film of this embodiment and an adhesive layer. The adhesive layer preferably contains at least one of an acrylic adhesive, a silicone adhesive, and a urethane adhesive. The thickness of the adhesive layer is preferably 10 to 70 μm. For details of the adhesive layer, see paragraphs 0046 to 0051 of WO 2021 / 029283, the contents of which are incorporated herein by reference. Furthermore, the bonding adhesive sheet preferably has a primer layer between the film of this embodiment and the adhesive layer. Such a bonding adhesive sheet is bonded to the surface of a resin molded product, for example. For details of the adhesive lamination sheet and the primer layer, please refer to paragraphs 0052 to 0077 of International Publication No. 2021 / 029283, the contents of which are incorporated herein by reference.

[0047] The pressure-sensitive adhesive sheet for lamination of the present embodiment can be used as a constituent material for various elements such as image display devices such as mobile phone terminals, smartphones, portable electronic toys, personal digital assistants, tablet devices, mobile personal computers, and wearable terminals, as well as stationary display devices such as liquid crystal televisions, liquid crystal monitors, desktop personal computers, car navigation systems, and automobile meters. In particular, it can be suitably used as a transparent conductive film for the liquid crystal members, or as a substrate material or protective material for various elements. More specifically, the film of this embodiment is preferably used as a masking film. More preferably, it is used as an anti-blocking film. It is also preferably used as a protective film for a transparent conductive film. In particular, it is preferably used as a transparent conductive film having a protective layer, an adhesive layer, a substrate, and an electrode layer in this order, in which at least one of the substrate and the protective layer (preferably at least the protective layer) is the film of this embodiment.

[0048] The transparent conductive film is also preferably used as a transparent conductive film for use in film sensors of touch panels, electronic paper, dye-sensitized solar cells, touch sensors, and the like. In addition to the above, the film of this embodiment is also preferably used as a film for applications requiring slidability and transparency. [Example]

[0049] The present invention will be explained in more detail below with reference to examples. The materials, amounts used, ratios, processing details, processing procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. If the measuring instruments used in the examples are difficult to obtain due to discontinuation or the like, measurements can be made using other instruments with equivalent performance.

[0050] 1.Raw materials Polycarbonate resin A1: Bisphenol A polycarbonate resin Aromatic polycarbonate resin obtained by interfacial polymerization using bisphenol A as the starting material, Mitsubishi Engineering Plastics Corporation, S-3000F, viscosity average molecular weight: 21,000, refractive index: 1.59

[0051] organic particles B1: Soliostar RA-I-35-AX, silicone-styrene particles (rubber-free), manufactured by Nippon Shokubai Co., Ltd., number average particle size: 3.6 μm, refractive index: 1.56 B2: Techpolymer SBX-4, styrene particles (rubber-free), manufactured by Sekisui Plastics Co., Ltd., number average particle diameter: 3.1 μm, refractive index: 1.59 B3: Optobeads 3500M, melamine resin particles (rubber-free), manufactured by Nissan Chemical Industries, Ltd., number average particle size: 2.5 μm, refractive index: 1.69 B4: SRB5104, manufactured by Fujikura Kasei Co., Ltd., acrylic-styrene particles (rubber-free), number average particle size: 0.6 μm, refractive index: 1.54 B5: Unipowder NMB-0520C, acrylic particles (rubber-free), manufactured by ENEOS Liquid Crystal Co., Ltd., number average particle size: 5.0 μm, refractive index: 1.49 B6: Techpolymer SBX-17, styrene particles (rubber-free), manufactured by Sekisui Plastics Co., Ltd., number average particle size: 9.1 μm, refractive index: 1.59

[0052] release agent C1: Glycerin monostearate, Riken Vitamin Co., Ltd. Rikemal S-100A

[0053] <Method for measuring the refractive index of polycarbonate resin> The refractive index of the polycarbonate resin was measured according to JIS K7142A method. The refractive index was measured using "Auto SE" manufactured by Horiba Ltd.

[0054] <Measurement of the number average particle size of organic particles> The number average particle size of organic particles was measured by observing the particles at 1000x magnification using a field emission scanning electron microscope and measuring the particle size from the photograph. The number average value of the measurements of 100 randomly selected particles was taken as the number average particle size (unit: μm). If the particles in the micrograph were not circular, the particle size was calculated by converting them into a circle of the same area. The field emission scanning electron microscope used was the "SU8220" manufactured by Hitachi High-Technologies Corporation.

[0055] <Measurement of refractive index of organic particles> The refractive index of the organic particles was measured in accordance with JIS K7142 B method. The refractometer used was an Atago "Abbe Refractometer 2T," and the microscope used was an Olympus "Small Measuring Microscope STM5-311."

[0056] 2. Examples 1 to 3 and Comparative Examples 1 to 6 <Pellet production> Each of the components described above was weighed out so as to obtain the amount added shown in Table 1. Each component in Table 1 is shown in parts by mass. After mixing for 10 minutes in a tumbler, the mixture was melt-kneaded at a cylinder temperature of 260°C in a vented twin-screw extruder ("TEX30α" manufactured by The Japan Steel Works, Ltd.) with a screw diameter of 32 mm, and pellets were obtained by strand cutting.

[0057] <Film manufacturing> The resulting pellets were used to produce a film in the following manner. The pellets obtained above were extruded into a molten state using a T-die melt extruder consisting of a vented twin-screw extruder (manufactured by The Japan Steel Works, Ltd., "TEX30α") ​​with a barrel diameter of 32 mm and a screw L / D of 31.5 at a discharge rate of 10 kg / h and a screw rotation speed of 166 rpm. The pellets were then cooled and solidified on a second roll to produce a film. The cylinder and die head temperatures were 260°C. The final film thickness was adjusted to the values ​​shown in Table 1 by changing the roll speed of the second roll.

[0058] Details of the second roll used are as follows. Second roll: JSW rigid metal roll (surface: hard chrome treated) Core diameter: outer diameter 250mm x width 600mm Roll temperature: 140℃

[0059] <Measurement of total light transmittance and haze> The total light transmittance (unit: %) and haze (unit: %) of the obtained film were measured under the conditions of a D65 light source and a 10° visual field. For the measurement, a haze meter ("HM-150" manufactured by Murakami Color Research Laboratory Co., Ltd.) was used.

[0060] <Measurement of dynamic friction coefficient> The dynamic coefficient of friction of the film was measured as the dynamic coefficient of friction against a film with a root mean square roughness of 0.093 μm. A film having a root mean square roughness of 0.093 μm and the film obtained above were placed so as to overlap each other, and the obtained film was slid over the film having a root mean square roughness of 0.093 μm under conditions of a thread speed of 100 mm / min and a load cell of 10 N, to measure the coefficient of dynamic friction. The friction coefficient measuring device used was a "Friction Tester" manufactured by Toyo Seiki Seisakusho, Ltd. The film with a root mean square roughness of 0.093 μm was a bisphenol A polycarbonate resin film with a masking film on one side (manufactured by Mitsubishi Gas Chemical Company, Inc., FE-2000, 100 μm thick). In this example, the masked side of the bisphenol A polycarbonate resin film with a masking film on one side was placed on top, and the long axis was fixed to the right edge of the test table with tape so that it coincided with the long axis of the test table. The resulting film was attached to the underside of a 63 mm × 63 mm, 200 g sled, and the polycarbonate resin film and the resulting film were placed so that they overlapped. The resulting film was slid as described above to measure the coefficient of dynamic friction. In Table 1, "x" means that measurement was not possible. In Comparative Example 3, the particle size of the organic particles was small and the irregularities exposed on the surface were small, and in Comparative Example 6, the film was too thick to create irregularities of sufficient size on the surface, so the films stuck together and the dynamic friction coefficient could not be measured.

[0061] <Measurement of root mean square roughness Rq> The surface roughness of the film used to measure the dynamic friction coefficient, which had a root mean square roughness of 0.093 μm, was measured using a surface roughness measuring device. The detector of the measuring instrument was set to an "integrated type," and a "standard drive unit" was attached to the detector's drive section. The film was fixed to a glass plate with tape, and the surface roughness measuring instrument was placed on top of it so that it would not move. Measurements were then carried out under the measurement conditions of the standard "JIS B 0601-2001," with a measurement speed of 0.5 mm / s, a cutoff value of 0.8, and three sections, and the root mean square roughness Rq was measured. The root mean square roughness Rq was calculated by measuring three times at different locations on the film and taking the average value. The measuring instrument used was the "SJ-210" manufactured by Mitutoyo Corporation.

[0062] <Evaluation of the roll shape> In the production of the above film, the speed of the second roll was adjusted so that the film would reach the specified thickness, and the take-up tension of the film winding machine was controlled to 200N. The film was wound 30m onto a paper tube with an inner diameter of 3 inches without using masking film, and the film's appearance was evaluated. Five experts evaluated the film and a majority vote was used. A: No wrinkles were generated and the film was wound up with a good appearance. B: Other than A and C above, for example, winding was possible but stuck and wrinkles occurred during winding. C: It was not possible to wind it along the paper tube.

[0063] <Visual appearance inspection> To evaluate the appearance of the film, the film was placed 1 m away from a fluorescent lamp and the appearance was evaluated when the light from the fluorescent lamp was transmitted through the film. The evaluation was carried out by five experts and judged by majority vote. A: It was transparent and it was easy to identify foreign matter in the film. B: Other than A and C above, for example, the film was slightly cloudy and it was somewhat difficult to distinguish foreign matter in the film. C: It was cloudy.

[0064] [Table 1] The amounts of each of the above components are in parts by mass.

[0065] 3. Manufacturing of adhesive film In Example 4 of WO 2021 / 029283, the substrate sheet 1 was replaced with the film described in Example 4 above, and the rest was carried out in the same manner to obtain an adhesive sheet. The adhesive layer at this time was laminated on the contact surface of the second roll. The obtained adhesive sheet was bonded to a bisphenol A polycarbonate resin film with a root mean square roughness of 0.093 μm (manufactured by Mitsubishi Gas Chemical Company, Inc., FE-2000, thickness 100 μm), and it was confirmed that no bubbles or the like were generated and the appearance was good. [Explanation of symbols]

[0066] 10 Transparent conductive film 11 Electrode layer (transparent conductive film) 12 Base material 13 Adhesive layer 14 Protective film 21 Polycarbonate resin film with a smooth surface 22 Polycarbonate resin film with finely textured surface

Claims

1. Per 100 parts by mass of polycarbonate resin, containing 0.01 to 0.45 parts by mass of organic particles having a number average particle diameter of 2.6 to 4.8 μm and a refractive index of 1.55 to 1.63, A film having a thickness of 20 μm or more and less than 500 μm, A film, wherein at least one surface of the film has a dynamic friction coefficient of 1.00 or less against a film having a root mean square roughness of 0.093 μm.

2. The film according to claim 1, wherein the total light transmittance of the film under a D65 light source and a 10° viewing angle condition is 86.0% or more.

3. 3. The film according to claim 1, wherein the film has a haze of less than 2.0% under conditions of a D65 light source and a 10° viewing angle.

4. The film according to any one of claims 1 to 3, wherein the number average particle size of the organic particles is 3.0 to 4.0 µm.

5. The film according to any one of claims 1 to 4, wherein the content of the organic particles is 0.01 to 0.40 parts by mass per 100 parts by mass of the polycarbonate resin.

6. The film of any one of claims 1 to 5, wherein the organic particles comprise styrene.

7. The film according to any one of claims 1 to 6, wherein the organic particles are rubber-free.

8. The film of any one of claims 1 to 7, which is a monolayer film.

9. A multilayer body comprising the film according to any one of claims 1 to 8 and at least one other layer.

10. The multilayer body of claim 9 , wherein the other layer comprises an adhesive layer.

11. A protective layer; An adhesive layer; A substrate; a transparent conductive film having, in this order, a first electrode layer and a second electrode layer, A transparent conductive film, wherein at least one of the substrate and the protective layer is the film according to any one of claims 1 to 8.

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