Functional film and method for manufacturing the same

Abstract

A functional film (1) of one embodiment includes a substrate (10) including an acetyl cellulose-based resin; a primer layer (20) including a filler (40) provided on the substrate (10); and a functional layer (30) including the filler (40) provided on the primer layer (20). The substrate (10) has a penetration layer (12) formed by penetration of the resin included in the primer layer (20) into a part of the substrate (10), and the thickness of the penetration layer (12) is greater than or equal to 0.1 μm and less than or equal to 3.5 μm. The thickness of the primer layer (20) is greater than or equal to 0.1 μm and less than or equal to 1.0 μm. The filler (40) is a silica particle with an average particle diameter of greater than or equal to 20 nm and less than or equal to 80 nm. The density of the filler (40) in the primer layer (20) is greater than or equal to one third and less than or equal to three quarters of the density of the filler (40) in the functional layer (30). The primer layer (20) and the functional layer (30) each include a resin, and the resin component of the primer layer (20) is the same as the resin component of the functional layer (30).

Description

Technical Field

[0001] This invention relates to functional membranes and methods for manufacturing the same. Background Technology

[0002] Functional films are components that perform optical functions such as anti-reflection, or protective functions such as hard coating or gas barrier.

[0003] Functional membranes are sometimes formed by depositing a functional layer on a substrate. In this case, the functional layer is formed to perform the desired function expected of the functional membrane.

[0004] In functional films where a functional layer is formed on a substrate, a film whose main component is resin is typically used as the substrate. On the other hand, the functional layer can usually be formed from organic materials, inorganic materials, or a combination of both.

[0005] Materials that combine organic and inorganic materials include, for example, materials in which numerous inorganic granular fillers are contained within a resin of organic material that forms a film.

[0006] When a functional layer is directly applied to a substrate, the adhesion between the substrate and the functional layer may not be sufficient, depending on the relationship between their materials. In such cases, an undercoat layer can sometimes be applied between the substrate and the functional layer to improve adhesion.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2021-24913 Summary of the Invention

[0010] When a functional layer contains granular fillers of inorganic materials within the resin, the desired function can be achieved through the fillers. However, the adhesion between the functional layer and the substrate can sometimes be compromised by the fillers. In contrast, as mentioned above, providing a primer layer can improve the adhesion between the functional layer and the substrate. However, if there are limitations on the thickness of the functional film, the thickness of the functional layer must be reduced by the amount of the primer layer, which may result in a reduction in the amount of filler. In this case, the function of the functional layer may be reduced.

[0011] The present invention was made in consideration of the above circumstances, and its object is to provide a functional film and a method thereof that can simply and effectively improve the adhesion between the substrate and the functional layer, thereby enabling the film to perform the desired function appropriately.

[0012] Methods for solving problems

[0013] One embodiment of the present invention relates to the following [1] to

[11] .

[0014] [1] A functional membrane comprising: a substrate comprising an acetylcellulose resin; a base coating comprising a filler disposed on the substrate; and a functional layer comprising a filler disposed on the base coating, wherein the substrate has a permeable layer on the base coating side, wherein a portion of the resin contained in the base coating permeates therethrough, the thickness of the permeable layer is 0.1 μm or more and 3.5 μm or less, the thickness of the base coating is 0.1 μm or more and 1.0 μm or less, wherein the filler in the base coating and the filler in the functional layer are silica particles with an average particle size of 20 nm or more and 80 nm or less, the density of the filler in the base coating is 1 / 3 or more and 3 / 4 or less of the density of the filler in the functional layer, the base coating and the functional layer comprise resin, and the resin composition of the base coating is the same as the resin composition of the functional layer.

[0015] [2] A functional membrane comprising: a substrate containing an acetylcellulose resin; a base coating containing a filler disposed on the substrate; and a functional layer containing a filler disposed on the base coating, wherein the substrate has a permeable layer formed by the resin contained in the base coating permeating to a portion thereof on the base coating side, the thickness of the permeable layer being 0.1 μm or more and 3.5 μm or less, the thickness of the base coating being 0.1 μm or more and 1.0 μm or less, the filler in the base coating and the filler in the functional layer being silica particles with an average particle size of 20 nm or more and 80 nm or less, and the filler in the functional layer being spaced 0.5 μm or more per 0.5 μm in cross-section along the thickness direction of the functional layer. 2 The filler in the aforementioned base coating is present in quantities of 90 to 150, and the filler content in the aforementioned base coating is approximately 0.2 μm per section in the thickness direction of the aforementioned base coating. 2 The number of elements present is between 15 and 45, and the base coating and the functional layer each contain resin, wherein the resin composition of the base coating is the same as that of the functional layer.

[0016] [3] A functional membrane comprising: a substrate containing an acetylcellulose resin; a base coating containing a filler disposed on the substrate; and a functional layer containing a filler disposed on the base coating, wherein the substrate has a permeable layer formed by the resin contained in the base coating permeating to a portion thereof on the base coating side, the thickness of the permeable layer being 0.1 μm or more and 3.5 μm or less, the thickness of the base coating being 0.1 μm or more and 1.0 μm or less, the filler in the base coating and the filler in the functional layer being silica particles with an average particle size of 20 nm or more and 80 nm or less, and the filler in the base coating being spaced at 0.2 μm per unit area in the cross-section along the thickness direction of the base coating. 2The number of elements present is between 15 and 45, and the base coating and the functional layer each contain resin, wherein the resin composition of the base coating is the same as that of the functional layer.

[0017] [4] A functional membrane comprising: a substrate comprising an acetylcellulose resin; a base coating comprising a filler disposed on the substrate; and a functional layer comprising a filler disposed on the base coating, wherein the substrate has a permeable layer on the base coating side, wherein a portion of the resin contained in the base coating permeates therethrough, the thickness of the permeable layer is 0.1 μm or more and 3.5 μm or less, the thickness of the base coating is 0.1 μm or more and 1.0 μm or less, wherein the filler in the base coating and the filler in the functional layer are silica particles with an average particle size of 20 nm or more and 80 nm or less, the density of the filler in the base coating is 15% or more and 30% or less in a cross section in the thickness direction of the base coating, and the base coating and the functional layer each comprise a resin, wherein the resin composition of the base coating is the same as the resin composition of the functional layer.

[0018] In the functional films described above [1] to [4], the resin composition of the base layer refers to all the resins contained in the base layer, and the types of resins contained therein are one or more. That is, the resin composition of the base layer refers to a substance composed of one or more resins contained in the base layer. The resin composition of the functional layer refers to all the resins contained in the functional layer, and the types of resins contained therein are one or more. That is, the resin composition of the functional layer refers to a substance composed of one or more resins contained in the functional layer.

[0019] In the functional membrane described above [1], the base layer may contain a resin and the functional layer may contain a resin. In this case, the resin components of the base layer and the resin components of the functional layer are both the same (single) resin.

[0020] In addition, in the functional film described above [1], the base layer may contain two resins and the functional layer may contain two resins. In this case, the types and mixtures of the two components (two resins) in the resin composition of the base layer are the same as the types and mixtures of the two components (two resins) in the resin composition of the functional layer.

[0021] In addition, in the functional film described above [1], the base layer may contain three or more resins and the functional layer may contain three or more resins. In this case, the types and mixtures of each component (each resin) in the resin composition of the base layer are the same as the types and mixtures of each component (each resin) in the resin composition of the functional layer.

[0022] [5] A method for manufacturing a functional membrane includes: a diluent coating step, wherein a diluent comprising a first resin composition containing filler diluted with a solvent is coated onto a substrate; a drying step, wherein a portion of the solvent is evaporated, thereby keeping the first resin composition in an uncured or semi-cured state; a setting step, wherein a second resin composition containing filler is set onto the diluent; and a curing step, wherein the first resin composition and the second resin composition are cured to form a base layer comprising a resin cured from the first resin composition on the substrate, and a functional membrane comprising a resin cured from the second resin composition is formed on the base layer. In the above-mentioned diluent coating process, a portion of the first resin composition in the diluent is allowed to penetrate into the substrate. In the above-mentioned drying process, a portion of the solvent is evaporated, thereby leaving residual solvent in the diluent. In the above-mentioned setting process, when the second resin composition is set on the diluent, the residual solvent is used to cause a portion of the second resin composition on the diluent to flow towards the diluent side, so that the density of the filler in the base layer is less than the density of the filler in the functional layer, and the filler contained in the first resin composition is the same as the filler contained in the second resin composition.

[0023] [6] The method for manufacturing a functional membrane as described in [5] above, wherein, in the setting step above, the heated second resin composition is set on the diluent above.

[0024] [7] The method for manufacturing a functional membrane as described in [5] or [6] above, wherein the proportion of the filler in the first resin composition is the same as the proportion of the filler in the second resin composition.

[0025] [8] The method for manufacturing a functional membrane as described in any one of [5] to [7] above, wherein the solvent is a ketone solvent.

[0026] [9] The method for manufacturing a functional membrane as described in any one of [5] to [8] above, wherein the filler is silica particles with an average particle size of 20 nm or more and 80 nm or less.

[0027]

[10] The method for manufacturing a functional membrane as described in any one of [5] to [9] above, wherein the first resin composition and the second resin composition are ionizing radiation-curable resins or thermosetting resins.

[0028]

[11] The method for manufacturing a functional membrane as described in [5] to

[10] above, wherein the substrate comprises an acetylcellulose resin.

[0029] The effects of the invention

[0030] According to the present invention, a functional film can be provided that can easily and effectively improve the adhesion between the substrate and the functional layer, thereby enabling it to perform the desired function appropriately. Attached Figure Description

[0031] Figure 1 This is a schematic diagram illustrating a functional membrane according to one embodiment.

[0032] Figure 2 This is a schematic diagram of a cross-section in the thickness direction of a functional membrane according to one embodiment.

[0033] Figure 3A This is a diagram showing a cross-sectional SEM image of a functional membrane in the thickness direction according to one embodiment.

[0034] Figure 3B It is shown in Figure 3A A diagram showing the steps for determining the density and number of fillers in a cross-section along the thickness direction of a functional membrane.

[0035] Figure 4A This is a diagram showing a cross-sectional SEM image of a modified example of a functional membrane in the thickness direction.

[0036] Figure 4B It is shown in Figure 4A A diagram illustrating the steps for determining the density and number of fillers in a cross-section along the thickness direction of the functional membrane in the modified example shown.

[0037] Figure 5A This is a diagram showing a cross-sectional SEM image of a functional membrane in the thickness direction of another modified example.

[0038] Figure 5B It is shown in Figure 5A A diagram illustrating the steps for determining the density and number of fillers in a cross-section along the thickness direction of the functional membrane in the modified example shown.

[0039] Figure 6 This is a flowchart illustrating a method for manufacturing a functional membrane according to one embodiment.

[0040] Figure 7 This is a diagram showing a manufacturing apparatus for implementing a method of manufacturing a functional membrane according to one embodiment.

[0041] Figure 8 This is a schematic diagram illustrating yet another variation of the functional membrane.

[0042] Figure 9 This is a schematic diagram illustrating yet another variation of the functional membrane.

[0043] Figure 10 This is a schematic diagram illustrating yet another variation of the functional membrane. Detailed Implementation

[0044] Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings.

[0045] It should be noted that the terms "sheet," "membrane," "plate," and "layer" used in this specification are not distinguished from each other solely based on different names. Therefore, for example, "sheet" also includes the concept of components that can be called membranes, plates, or layers.

[0046] Furthermore, in this specification, "sheet surface (plate surface, film surface)" refers to a surface that aligns with the planar direction (surface direction) of the sheet-like member when viewed holistically and globally. Additionally, in this specification, the normal direction of the sheet-like member refers to the direction normal to the sheet surface of the sheet-like member. Furthermore, in this invention and in this embodiment, the term "resin" is sometimes used only. In this case, "resin" refers to synthetic resin.

[0047] <Functional membranes>

[0048] First, a functional membrane 1 according to one embodiment will be described. Figure 1 This is a schematic diagram illustrating the functional membrane 1 of this embodiment. Figure 2 This is a schematic diagram of a cross-section of the functional membrane 1 in the thickness direction.

[0049] like Figure 1 and Figure 2 As shown, the functional membrane 1 includes a substrate 10, a base coating 20 disposed on the substrate 10, and a functional layer 30 disposed on the base coating 20.

[0050] It should be noted that, to be precise, the base coating 20 is configured to be in direct contact with one of the surfaces of the opposite pair of substrates 10 in the thickness direction. The functional layer 30 is configured to be in direct contact with the surface of the opposite pair of the base coating 20 in the thickness direction.

[0051] (Substrate)

[0052] The substrate 10 is a film-like component having two opposing surfaces in the thickness direction. The substrate 10 may or may not be visible light transmittant. If it is visible light transmittant, the preferred value of the visible light transmittance varies depending on the application of the functional film 1.

[0053] For example, when the display surface of the display device is provided with a functional film 1, the substrate 10 is preferably colorless and transparent, and its total light transmittance is preferably 87% or more, more preferably 90% or more. When the display surface of the display device is provided with a functional film 1, the refractive index of the substrate 10 can be 1.46 or more and 1.70 or less, 1.48 or more and 1.65 or less, 1.52 or more and 1.64 or less, 1.54 or more and 1.64 or less, or 1.56 or more and 1.64 or less. When the display surface of the display device is provided with a functional film 1, and it is desirable to control the anisotropy of light transmitted through the substrate 10, the substrate 10 can be made of a biaxially oriented film.

[0054] It should be noted that the substrate 10 may have ionizing ray transmittance, such as ultraviolet transmittance, or non-ionizing ray transmittance. In the manufacturing process of the functional film 1, ionizing ray transmittance is sometimes preferred; in such cases, ensuring ionizing ray transmittance of the substrate 10 can advantageously facilitate manufacturing. Furthermore, in this embodiment, the substrate 10 may have visible light transmittance and ultraviolet transmittance. On the other hand, in applications such as food packaging, the visible light transmittance of the substrate 10 may be low or non-visible light transmittance.

[0055] The substrate 10 can be, for example, a film containing synthetic resins such as acetyl cellulose resin, polyester resin, polyolefin resin, and acrylic resin as its main component. It should be noted that the main component refers to the component that comprises 50% or more of the total components constituting a substance, or the component with the highest content. It should also be noted that the substrate 10 can be a relatively rigid, plate-like component. However, the thermal shrinkage rate, conductivity, and other physical properties of metal films differ significantly from those of organic resins, and therefore, they are sometimes unsuitable for the substrate 10.

[0056] Acetylcellulose-based resins include, for example, triacetylcellulose (TAC) and diacetylcellulose. Among them, TAC is an advantageous material when it is desirable to ensure high total light transmittance.

[0057] Polyester resins include polyethylene terephthalate (PET), polypropylene terephthalate (PEN), and polyethylene naphthalate. Polyolefin resins include polyethylene, polypropylene, and polymethylpentene. Acrylic resins include polymethyl methacrylate, polyethyl methacrylate, and polyethyl acrylate. It should be noted that the material of the substrate 10 can also be a material other than those listed above.

[0058] The thickness of the substrate 10 is not particularly limited, and can be, for example, 10 μm or more and 200 μm or less. From the perspective of operability, the lower limit of the thickness of the substrate 10 is preferably 15 μm or more, and more preferably 25 μm or more. From the perspective of thin film formation, the thickness of the substrate 10 is preferably 150 μm or less.

[0059] In addition, such as Figure 1 and Figure 2 As shown, the substrate 10 has a substrate main layer 11 and a permeation layer 12, and a base coating layer 20 is disposed on the permeation layer 12. The permeation layer 12 is formed by the resin contained in the base coating layer 20 permeating into a portion of the substrate 10, and is formed on the side of the base coating layer 20 in the substrate 10.

[0060] As detailed below, the base layer 20 is formed from a diluent prepared by diluting a polymerizable resin composition with a solvent. After applying the diluent, the solvent in the diluent evaporates and the resin composition polymerizes; in other words, it is formed by curing. Here, when applying the diluent, firstly, a substrate for the penetrating layer 12 is formed on the substrate 10. When the aforementioned diluent is applied to the surface of the substrate 10, the solvent in the diluent penetrates from the surface of the substrate 10 into the interior of the substrate 10, causing the substrate 10 to swell. At this time, a portion of the resin composition in the diluent also penetrates into the substrate 10, thus forming the substrate for the penetrating layer 12. Furthermore, in this penetrating state, as the base layer 20 is formed, the solvent evaporates and the resin composition partially cures, thereby forming the penetrating layer 12.

[0061] From the perspective of reliably forming the permeation layer 12, it is preferable that the solvent can easily permeate into the substrate 10. In this case, it is preferable that the substrate 10 has high water absorption (liquid absorption). Acetyl cellulose resins, especially TAC, are synthetic resins with relatively high water absorption (liquid absorption), generally higher than PET and PC. Therefore, from the perspective of forming the permeation layer 12, it is preferable to use a TAC membrane with TAC as the main component as the substrate 10. In this embodiment, the substrate 10 contains an acetyl cellulose resin, specifically it is composed of a TAC membrane. In addition, when the substrate 10 is composed of a biaxially oriented film, there is a tendency for the solvent to easily permeate into the substrate 10, which is beneficial to the formation of the permeation layer 12. Therefore, the substrate 10 can be composed of a biaxially oriented film formed of an acetyl cellulose resin. In addition, from the perspective of forming the permeation layer 12, the wettability of the substrate 10, when measured according to JISK6768:1999, can be 30 mN / m or more and 60 mN / m or less, or 40 mN / m or more and 50 mN / m. Furthermore, it is sometimes undesirable for the molecular weight of the substrate 10 to be too high during the formation of the permeation layer 12. From this perspective, the weight-average molecular weight of the substrate 10 can be between 20,000 and 1,000,000, or between 25,000 and 800,000. The weight-average molecular weight is determined by gel permeation chromatography (GPC) using tetrahydrofuran solvent.

[0062] When the substrate 10 is a transparent substrate, the color and / or haze are usually different between the main substrate layer 11, in which the resin of the base coating 20 is not impregnated, and the impregnated layer 12, in which the resin of the base coating 20 is impregnated. Figure 3A This is an example of a SEM image of a cross-section in the thickness direction of functional membrane 1. Figure 3A In the middle, the substrate 10 has a substrate main layer 11 and a penetration layer 12, and can know the situation where the color of the penetration layer 12 is darker than the color of the substrate main layer 11.

[0063] The presence of the permeation layer 12 on the substrate 10 can be verified by visually examining a SEM image of the exposed cross-section of the functional membrane 1 cut along its thickness direction as described above. It should be noted that images obtained using a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM) can also be used for verification. Alternatively, component analysis can be used to verify whether the portion on the undercoat 20 side of the substrate 10 is mixed with the resin that is the main component of the substrate 10 and the resin contained in the undercoat 20, thereby determining the presence or absence of the permeation layer 12. The component analysis method in this case can also be infrared spectroscopy, gas chromatography-mass spectrometry, etc.

[0064] It should be noted that the permeation layer 12 does not necessarily need to be formed on the substrate 10. However, with the permeation layer 12 formed, the adhesion between the substrate 10 and the primer layer 20 is improved. As a result, the adhesion between the substrate 10 and the functional layer 30 is also improved.

[0065] The thickness of the permeation layer 12 is preferably 0.1 μm or more and 3.5 μm or less. When the thickness of the permeation layer 12 is 0.1 μm or more, good adhesion can be ensured. On the other hand, it is not preferable for the thickness of the permeation layer 12 to be too large. For example, from the perspective of visible light transmittance, the thickness of the permeation layer 12 is preferably 3.5 μm or less.

[0066] (Base coat)

[0067] The base coating 20, for example, contains resin 21 as a polymer as its main component. In detail, Figure 2 The base coating 20 shown in this embodiment has a resin 21 and numerous fillers 40 retained in the resin 21. The base coating 20 is a layer located between and attached to the two components for bonding them. Attachment refers to the bonding of the two contacting components through at least one of the following chemical bonds: anchoring effect, intermolecular attraction, and covalent bonds. As described above, the base coating 20 is positioned in direct contact with one of the faces of the substrate 10 facing each other in the thickness direction. The functional layer 30 is positioned in direct contact with the face of the base coating 20 facing each other in the thickness direction, opposite to the side opposite to the substrate 10. Therefore, the base coating 20 is located between the substrate 10 and the functional layer 30, and is attached to both the substrate 10 and the functional layer 30.

[0068] As described above, the base coating 20 is formed by applying a diluted solution, obtained by diluting a polymerizable resin composition with a solvent, to the substrate 10, followed by evaporation of the solvent and polymerization of the resin composition, in other words, curing it. That is, the base coating 20 is formed as a substance containing, for example, resin 21, which is polymerized from the polymerizable resin composition, as a main component. Details will be described later; in this embodiment, the steps of evaporating the solvent and polymerizing (curing) the resin composition are performed separately.

[0069] As an example, the resin 21 contained in the base coating 20 of this embodiment is formed from a single resin, excluding the filler 40; in other words, it is formed by curing a single resin composition. However, the base coating 20 may also be formed by curing a substance composed of two or more resin compositions. It should be noted that the term "polymerizable resin composition" in this embodiment refers to a substance containing a polymerizable resin material and, as needed, a polymerization initiator and additives. In this embodiment, the resin composition also contains the filler 40.

[0070] The polymerization of the above-mentioned resin composition can be initiated by ionizing radiation and / or crosslinking, or by heating.

[0071] The polymerizable resin material contained in the resin composition used to form the base coating 20 is at least one of polymerizable monomers, oligomers, and prepolymers.

[0072] Monomers polymerized by ionizing rays that can be used as polymerizable resin materials can be monofunctional or polyfunctional monomers. Monofunctional monomers are, for example, (meth)acrylate monomers. Polyfunctional monomers are, for example, (meth)acrylate monomers having two or more (2-functional) and preferably three or more (3-functional) polymerizable unsaturated bonds in the molecule. As multifunctional (meth)acrylates, examples include ethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polyethylene glycol dimethacrylate, hydroxypentanoic acid neopentyl glycol dimethacrylate, dicyclopentyl dimethacrylate, caprolactone-modified dicyclopentenyl dimethacrylate, ethylene oxide-modified dimethacrylate phosphate, allylated cyclohexyl dimethacrylate, and isocyanurate dimethacrylate. These monomers include trimethylolpropane tri(meth)acrylate, ethylene oxide-modified trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid-modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, tri(acryloyloxyethyl)isocyanurate, propionic acid-modified dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ethylene oxide-modified dipentaerythritol hexa(meth)acrylate, and caprolactone-modified dipentaerythritol hexa(meth)acrylate. These monomers can be used individually or in combination of two or more.

[0073] Oligomers or prepolymers polymerized by ionizing radiation that can be used as polymerizable resin materials include, for example, urethane (meth)acrylates, polyester (meth)acrylates, epoxy (meth)acrylates, melamine (meth)acrylates, polyfluoroalkyl (meth)acrylates, silicone (meth)acrylates, etc. These polymerizable oligomers or prepolymers can be used alone or in combination of two or more. In this specification, when a layer is formed by polymerizing two or more monomers, oligomers, or prepolymers, the resin composition of the layer is interpreted as a substance containing two or more resins (polymer components).

[0074] In addition, the polymerizable resin material contained in the resin composition can be a thermosetting resin. In this case, for example, it can be an unsaturated polyester resin, a polyurethane resin (including two-component curable polyurethane), an epoxy resin, an amino alkyd resin, a phenolic resin, a urea resin, a diallyl phthalate resin, a melamine resin, a guanidine resin, a melamine-urea cocondensation resin, a silicone resin, a polysiloxane resin, etc.

[0075] When the functional film 1 is provided on the display surface of the display device, the resin 21 contained in the base coating 20 is transparent. Furthermore, it is preferable that the resin 21 has high light transmittance. Additionally, the refractive index of the resin 21 when the functional film 1 is provided on the display surface of the display device can be 1.40 or higher and 1.55 or lower. Moreover, the refractive index of the resin 21 in this case can be lower than or equal to the refractive index of the substrate 10.

[0076] Furthermore, as described above, the penetration layer 12 in the substrate 10 is formed by the resin contained in the primer layer 20 penetrating into the substrate 10. From the perspective of high light transmittance and ease of penetration into the substrate 10 during penetration before curing, the resin 21 contained in the primer layer 20 can be an acrylic resin, especially pentaerythritol tri(meth)acrylate or dipentaerythritol hexa(meth)acrylate.

[0077] Furthermore, the primer layer 20 is not intended to peel off the substrate 10 and the functional layer 30 or to bond them to other components after the substrate 10 and the functional layer 30 have been bonded. Therefore, the primer layer 20 does not possess adhesive properties such as heat-sensitive adhesion. Based on this, the resin 21 contained in the primer layer 20 can be a polyurethane resin. Additionally, the primer layer 20 in this embodiment does not contain a curing agent.

[0078] The resin 21 is formed into a film covering the surface of the substrate 10, and the filler 40 is retained therein. The filler 40 is appropriately determined according to the function of the functional film 1, and in this embodiment, it is also commonly included in the functional layer 30.

[0079] The filler 40 is, for example, inorganic particles, and in this embodiment, it is silica particles. However, the material of the filler 40 can also be titanium dioxide, glass beads, calcium carbonate, aluminum powder, mica, graphite, carbon black, carbon fiber, etc.

[0080] When inorganic particles are used as filler 40, the overall hardness of the functional membrane 1 can be improved, for example. Furthermore, the desired optical functions can also be obtained. On the other hand, inorganic particles sometimes do not exhibit good adhesion to the substrate 10, but in this embodiment, adhesion is compensated for by forming the permeation layer 12 as described above. It should be noted that the permeation layer 12 sometimes also contains filler 40. The shape of filler 40 is appropriately determined according to the function of the functional membrane 1, and may be, for example, spherical, needle-like, or plate-like.

[0081] In this embodiment, the filler 40 is made of silica particles, which are transparent. Therefore, when the functional film 1 is entirely transparent, it can perform optical functions such as transmission, refraction, and reflection. When the functional film 1 is provided on the display surface of the display device, the refractive index of the filler 40, which is made of silica particles, can be 1.40 or higher and 1.50 or lower. The refractive index of the filler 40, which is made of silica particles, can be lower than the refractive index of the resin 21. In this case, in particular, the difference between the refractive index of the filler 40, which is made of silica particles, and the refractive index of the resin 21 can be 0.01 or higher and 0.05 or lower.

[0082] The thickness of the base coating 20 is preferably 0.1 μm to 1.0 μm. As described later, the average particle size of the filler 40 is, for example, 10 nm to 100 nm. In this case, when the thickness of the base coating 20 is 0.1 μm or more, good adhesion can be ensured. If the thickness of the base coating 20 is too small, a large amount of filler 40 may be exposed to the outside from the resin 21, and there is a tendency for reduced adhesion. On the other hand, it is not desirable for the thickness of the base coating 20 to become too large. For example, from the perspective of visible light transmittance, the thickness of the base coating 20 is preferably 1.0 μm or less.

[0083] The size of the filler 40 is not particularly limited and is appropriately determined according to the function of the functional membrane 1. The average particle size of the filler 40 can be 10 nm to 100 nm. Preferably, the average particle size of the filler 40 is 20 nm to 80 nm, more preferably 35 nm to 65 nm. If the particle size is less than 20 nm, the cost increases. Furthermore, if the filler 40 is large, it may sometimes result in a decrease in optical properties, such as increased haze. The average particle size of the filler 40 is determined by dynamic light scattering according to JIS Z8828:2019. The average particle size can be determined using a dynamic light scattering particle size distribution measuring device (UPA150) manufactured by Microtrac BEL.

[0084] In this embodiment, the base coating 20 contains filler 40, thus increasing its hardness. However, the base coating 20 is not a typical hard coating. Therefore, the thickness of the base coating 20 can be small, and it can be non-hard. The thickness of the base coating 20 can be 0.1 μm to 1.0 μm, less than 1.0 μm, or 0.9 μm or less. Furthermore, the pencil hardness of the base coating 20 can be 3H or less. Considering optical performance and the bonding strength between the substrate 10 and the base coating 20, the amount of filler 40 can be relatively small. For example, the proportion of filler 40 in the overall base coating 20 can be 5% by mass to 60% by mass, or 20% by mass to 45% by mass.

[0085] Furthermore, when the average particle size of filler 40 is 20 nm to 80 nm, the filler 40 in the base coating 20 can be distributed in a cross-section along the thickness direction of the base coating 20 at a density of 0.2 μm per unit area. 2 It can exist in numbers between 15 and 45, or between 20 and 40, or between 25 and 35.

[0086] In determining the number of filler 40 in the cross-section described here, firstly, for example, Figure 3A The image shows a cross-sectional SEM image of the functional membrane 1 along its thickness direction. Next, the 0.2 μm diameter of the undercoat 20 in the SEM image is determined. 2 Three ranges (0.796 (μm) × 0.251 (μm)) were defined. Then, using the prescribed functions of image processing software (product name "ImageJ", manufactured by the National Institutes of Health, USA), the number of circular or approximately circular regions that could be identified as the area occupied by one filler 40 in each of the three ranges was counted, thereby determining the number of filler 40s. Furthermore, the average number of filler 40s in the three ranges was determined as the average number per 0.2 μm. 2 The number of packing materials is 40.

[0087] That is, the number of fillers 40 present in the cross-section along the thickness direction of the base coating 20 is the number of fillers 40 in the base coating 20 measured by image processing software in a magnified image of the cross-section along the thickness direction of the functional film 1, specifically the average number in three local regions. Details regarding the measurement of the number are described below.

[0088] The number of fillers 40 in the base coating 20 is per 0.2 μm of the cross-section in the thickness direction. 2 In a configuration of 15 to 45 fillers 40, the characteristics change when there are 45 fillers 40 with an average particle size of 80 nm and 10 fillers 40 with an average particle size of 10 nm. However, the inventors of this application have confirmed that when the filler 40 has an average particle size of 80 nm, the characteristics change when there are 0.2 μm fillers 40. 2 With 45 particles present, a good adhesion can be ensured between the base coating 20 and the substrate 10. Furthermore, the inventors of this application have confirmed that: with filler 40 having an average particle size of 10 nm, at every 0.2 μm... 2 With 15 units present, packing 40 can perform its intended function.

[0089] (Functional layer)

[0090] Functional layer 30, for example, contains resin 31 as a polymer as a main component, specifically, such as Figure 2As shown, the membrane comprises a resin 31 and numerous fillers 40 held within the resin 31. In this embodiment, the functional layer 30 performs the desired function expected in the functional membrane 1 through the included fillers 40.

[0091] The functional layer 30 can perform functions such as anti-glare and anti-reflection optical functions, hard coating, gas barrier, ensuring conductivity, ensuring magnetism, abrasion resistance, heat insulation, flame retardancy, and UV blocking. It should be noted that this functional layer 30 sometimes does not contain fillers to perform the desired functions.

[0092] In this embodiment, the base layer 20 and the functional layer 30 contain the same resin. Specifically, the resin 21 contained in the base layer 20 and the resin 31 contained in the functional layer 30 are the same, that is, they are composed of the same resin components. In other words, the resin 21 and the resin 31 are formed by curing a resin composition with the same polymerizability.

[0093] In detail, the resin 31 included in the functional layer 30 of this embodiment is formed from a single resin, excluding the filler 40; in other words, it is formed from a single resin composition. Furthermore, this single resin is the same as the resin 21 corresponding to the base coat 20, and the single resin composition is the same as the resin composition forming the base coat 20. However, the functional layer 30 may also be formed by mixing and curing two or more resin compositions. In this case, the base coat 20 is preferably formed by curing a substance containing two or more identical resin compositions, which allows for a more efficient manufacturing process.

[0094] When the base coating 20 contains two or more resins and the functional layer 30 contains two or more resins, if at least one resin in the base coating 20 and at least one resin in the functional layer 30 are of the same type, the bonding strength between the base coating 20 and the functional layer 30 is improved. The base coating 20 and the functional layer 30 can be configured as follows.

[0095] When the base coat 20 contains two or more resins and the functional layer 30 contains two or more resins, a portion of the resin component of the base coat 20 and a portion of the resin component of the functional layer 30 may be composed of the same substance, but the remaining portion of the resin component of the base coat 20 other than the aforementioned portion may differ from the remaining portion of the resin component of the functional layer 30 other than the aforementioned portion. The mixing ratio of the portion of the resin component of the base coat 20 within the resin component of the base coat 20 may differ from the mixing ratio of the portion of the resin component of the functional layer 30 within the functional layer 30.

[0096] Here, the statement that a portion of the resin component of the base layer 20 and a portion of the resin component of the functional layer 30 are composed of the same substance means that (i) or (ii) below.

[0097] (i) A portion of the resin component of the base coating 20 is composed of a resin. Furthermore, a portion of the resin component of the functional layer 30 is composed of the same resin as a portion of the resin component constituting the base coating 20.

[0098] (ii) A portion of the resin component of the base coating 20 is composed of two or more resins. Furthermore, a portion of the resin component of the functional layer 30 is composed of two or more resins of the same type and blended composition as the two or more resins constituting a portion of the resin component of the base coating 20. It should be noted that the blending of two or more resins mentioned here refers to the blending ratio within a portion (the blending ratio of the two or more resins).

[0099] It should be noted that the difference between the remaining portion of the resin composition of the base layer 20 other than the aforementioned portion and the remaining portion of the resin composition of the functional layer 30 other than the aforementioned portion means that: (a) when the two remaining portions are composed of one type of resin, the types of one type of resin are different; (b) when the two remaining portions are composed of two or more types of resin, the types of a portion of the two or more types of resin constituting the two are different; or (c) when the two remaining portions are composed of two or more types of resin, the types of all the resin constituting the two are the same, but the mixtures of the two or more types of resin within the remaining portions constituting the two are different from each other.

[0100] Furthermore, as described above, when a portion of the resin composition of the base coating 20 is the same as a portion of the resin composition of the functional layer 30, the aforementioned portion of the resin composition of the base coating 20 is preferably 50 parts by mass or more and less than 100 parts by mass relative to 100 parts by mass of the resin composition of the base coating 20, and the aforementioned portion of the resin composition of the functional layer 30 is preferably 50 parts by mass or more and less than 100 parts by mass relative to 100 parts by mass of the resin composition of the functional layer 30. Moreover, the aforementioned portion of the resin composition of the base coating 20 or the functional layer 30 may be 60 parts by mass or more and less than 100 parts by mass relative to the corresponding 100 parts by mass, 70 parts by mass or more and less than 100 parts by mass relative to 100 parts by mass, 80 parts by mass or more and less than 100 parts by mass relative to 100 parts by mass, or 90 parts by mass or more and less than 100 parts by mass relative to 100 parts by mass. This sufficiently improves the bonding strength between the base coating 20 and the functional layer 30.

[0101] In addition, when the base coating 20 contains two or more resins and the functional layer 30 contains two or more resins, a portion of the resin component of the base coating 20 and a portion of the resin component of the functional layer 30 may be made of the same material, and the remaining portion of the resin component of the base coating 20 other than the aforementioned portion and the remaining portion of the resin component of the functional layer 30 other than the aforementioned portion may be made of the same material, but the mixing of the aforementioned portion and the remaining portion of the resin component of the base coating 20 and the mixing of the aforementioned portion and the remaining portion of the resin component of the functional layer 30 are different.

[0102] Here, the fact that a portion (remaining portion) of the resin component of the base layer 20 and a portion (remaining portion) of the resin component of the functional layer 30 are made of the same material means as described below (iii) or (iv).

[0103] (iii) A portion (the remainder) of the resin component of the base coating 20 is composed of a resin. Furthermore, a portion (the remainder) of the resin component of the functional layer 30 is composed of the same resin as the portion (the remainder) of the resin component constituting the base coating 20.

[0104] (iv) A portion (the remaining portion) of the resin component of the base coating 20 is composed of two or more resins. Furthermore, a portion (the remaining portion) of the resin component of the functional layer 30 is composed of two or more resins of the same type and blended composition as the two or more resins constituting a portion (the remaining portion) of the resin component of the base coating 20. It should be noted that the blending of two or more resins mentioned here refers to the blending ratio (the blending ratio of two or more resins) within a portion (the remaining portion).

[0105] As in this embodiment, when the resin 21 contained in the base layer 20 is the same as the resin 31 contained in the functional layer 30, the resin 21 and resin 31 become the same interface, and can be partially or completely fused to form chemical bonds. Consequently, their coefficients of linear expansion are the same or approximately the same, thereby improving the adhesion between the base layer 20 and the functional layer 30. It should be noted that the identity of the resin 21 contained in the base layer 20 and the resin 31 contained in the functional layer 30 can also be verified through component analysis. Specifically, this can be verified using infrared spectroscopy, gas chromatography-mass spectrometry, etc.

[0106] Furthermore, in this embodiment, the resin 21 contained in the base layer 20 is the same as the resin 31 contained in the functional layer 30, but the formation process of the functional layer 30 is different from that of the base layer 20. Specifically, the functional layer 30 is formed by directly curing the resin composition itself without using a solvent to dilute it. In this case, the resin composition used to form the functional layer 30 is the same as the polymerizable resin composition used to form the base layer 20 in this embodiment.

[0107] The polymerizable resin composition used to form the functional layer 30 is the same as the polymerizable resin composition used to form the primer layer 20. Therefore, it may contain at least one of polymerizable monomers, oligomers, and prepolymers and a polymerization initiator, or at least one of polymerizable monomers, oligomers, and prepolymers, a polymerization initiator, and an additive. In this embodiment, the resin composition for forming the functional layer 30 also includes filler 40. The additive may be a leveling agent. When the polymerizable resin composition used to form the primer layer 20 contains a polymerization initiator and / or additives, it is preferable that the resin composition used to form the functional layer 30 contains the same polymerization initiator and / or additives as those contained in the polymerizable resin composition used to form the primer layer 20. In this case, the cured primer layer 20 and functional layer 30 may contain the same polymerization initiator and / or additives.

[0108] The monomer polymerizable by ionizing rays that can be used as a polymerizable resin material contained in a resin composition can be a monofunctional monomer or a polyfunctional monomer. The substances that can be used as monofunctional monomers, polyfunctional monomers, oligomers, and prepolymers are the same as those exemplified in the description of the primer coating 20.

[0109] It should be noted that when the functional film 1 is provided on the display surface of the display device, the resin 31 contained in the functional layer 30 is transparent. Furthermore, the light transmittance of the resin 31 is preferably high. Regarding the refractive index of the resin 31 when the functional film 1 is provided on the display surface of the display device, since the resin 21 contained in the base layer 20 and the resin 31 contained in the functional layer 30 are the same in this embodiment, it can be 1.40 or higher and 1.55 or lower.

[0110] Furthermore, in this embodiment, the filler 40 included in the functional layer 30 is the same as the filler 40 included in the base layer 20. It should be noted that, in this embodiment, the filler 40 included in the base layer 20 is the same as the filler 40 included in the functional layer 30, but it may also include different fillers. In this case, the functionality of the functional membrane can be expanded.

[0111] On the other hand, in this embodiment, such as Figure 2 and Figure 3A As shown, the density of filler 40 in the base coating 20 is less than the density of filler 40 in the functional layer 30. In this case, the amount of filler 40 in the base coating 20 that contacts the substrate 10 can be suppressed, and the adhesion between the substrate 10 and the base coating 20 is improved. On the other hand, between the base coating 20 and the functional layer 30, the contact area between resin 21 and resin 31 of the same composition is increased, thus the adhesion between the base coating 20 and the functional layer 30 can be improved.

[0112] The density of filler 40 was determined using a scanning electron microscope (SEM), a transmission electron microscope (TEM), or a scanning transmission electron microscope (STEM), and image processing software was used.

[0113] Specifically, a scanning electron microscope (SEM), a transmission electron microscope (TEM), or a scanning transmission electron microscope (STEM) is used to read an image of the cross-section of the functional membrane 1 taken at a resolution of 150 dpi and a magnification of 50,000 using image processing software (product name "ImageJ", manufactured by the National Institutes of Health, USA), and then perform black and white binarization processing. In detail, the following steps (1) to (4) are performed.

[0114] (1) Adjust the number of pixels of the measured image to 640×480.

[0115] (2) Set the actual scale for the image with adjusted pixel count.

[0116] (3) If the image is not an 8-bit grayscale image, convert the image to an 8-bit grayscale image. Then, select "IJ_ISODATA" and "B&W" for automatic binarization to binarize the grayscale image into a black and white image. Then, use "Watershed" to segment overlapping particles.

[0117] (4) Then, the area ratio of the packing is determined by using the automatic analysis of "Analize Partcles". The area ratio of the packing corresponds to the density of the packing.

[0118] Figure 3B It is shown in Figure 3A The diagram shows the steps for determining the density of filler 40 in a cross-section of the SEM image.

[0119] In detail, when measuring the density of functional layer 30, three functional layers 30 are selected from the images following (3) above. Figure 3B The 0.5μm shown 2 The above-described automatic analysis was performed on the range of (0.796(μm) × 0.628(μm)) (Box F1). Furthermore, the average value of the three ranges was determined as the density of the filler 40 in the functional layer 30.

[0120] When determining the density of the base coating 20, three images of the base coating 20 from the images following (3) above are selected. Figure 3B The 0.2μm shown 2The above automatic analysis was performed on the range of (0.796 (μm) × 0.251 (μm)) (box F2). The average of the three ranges was determined as the density of the filler 40 in the base coat 20. It should be noted that in "Analyze Parts", the size (item: Size) of the portion identified as filler was set to 0.0001-0.10 (μm). 2 Additionally, the circularity of the portion identified as filler is set to 0.50-1.0.

[0121] in addition, Figure 3B The aspect ratio of the frames (F1, F2) shown is not particularly limited and can be arbitrary. For example, when the thickness of the base coating 20 is 0.1 μm, the range of 0.1 μm in length × 2 μm in width can be defined as the second frame F2.

[0122] The density of filler 40 in the primer layer 20, determined through the above steps, can be 5% to 50%. The density of filler 40 in the primer layer 20 can be 15% to 30%, particularly preferably 17.5% to 22.5%. When it is 15% to 30%, it functionally contributes to the functional layer 30, while also improving the adhesion between the substrate 10 and the primer layer 20, and between the primer layer 20 and the functional layer 30. Especially when it is 17.5% to 22.5%, the adhesion becomes reliably good. The density of filler 40 in the functional layer 30, determined through the above steps, can be 15% to 90%. The density of filler 40 in the functional layer 30 is appropriately selected based on the desired function. However, from the perspective of ensuring functionality and good adhesion with the primer layer 20, the density of filler 40 in the functional layer 30 can be 30% to 60%, 37.5% to 50%, or 37.5% to 45%.

[0123] It should be noted that the density of the filler 40 in the base coating layer 20 can be more than 1 / 3 and less than 3 / 4, more than 1 / 2 and less than 3 / 4, or more than 1 / 3 and less than 1 / 2 of the density of the filler 40 in the functional layer 30. However, the density of the filler 40 in the base coating layer 20 can also be the same as the density of the filler 40 in the functional layer 30.

[0124] In this embodiment, the filler 40 is silica particles. When the functional film 1 is entirely transparent, it can perform optical functions such as transmission, refraction, and reflection. Furthermore, as described above, the density of the filler 40 in the base layer 20 is less than the density of the filler 40 in the functional layer 30. In this case, if the refractive index of the silica particles is less than the refractive index of the resins 21 and 31, then the overall refractive index of the base layer 20 is greater than the overall refractive index of the functional layer 30. Here, when the density of the filler 40 in the base layer 20 is more than 1 / 3 and less than 3 / 4 of the density of the filler 40 in the functional layer 30, it is easy to form a layer structure in which the refractive index decreases uniformly in the order of substrate 10, base layer 20, and functional layer 30. When this layer structure is achieved, the refractive index of the substrate 10 is preferably 1.46 or higher. It should be noted that the aforementioned uniform decrease refers to a decrease in refractive index in the order of substrate 10, base layer 20, and functional layer 30 when the refractive index difference between the substrate 10 and base layer 20 and the refractive index difference between the base layer 20 and functional layer 30 is relatively small. The aforementioned relatively small state refers to, for example, 0.05 or less. If it is configured in this way, light can easily pass through.

[0125] Furthermore, in this embodiment, the functional layer 30 includes filler 40, thus increasing its hardness. It is also expected that the functional layer 30 will ensure a certain level of hardness. From this perspective, the thickness of the functional layer 30 can be more than 2 times but less than 100 times, more than 5 times but less than 50 times, or more than 10 times but less than 30 times the thickness of the base layer 20. Additionally, the thickness of the functional layer 30 can be more than 2 μm but less than 10 μm, more than 4 μm but less than 8 μm, or more than 5 μm but less than 7 μm. Furthermore, the pencil hardness of the functional layer 30 can be 3H or higher, preferably 4H or higher. Additionally, the proportion of filler 40 in the functional layer 30 as a whole can be more than 10% by mass but less than 60% by mass, more than 15% by mass but less than 40% by mass, or more than 25% by mass but less than 35% by mass.

[0126] Furthermore, when the average particle size of the filler 40 is between 20 nm and 80 nm, the filler 40 in the functional layer 30 has a particle size of approximately 0.5 μm in the cross-section along the thickness direction of the functional layer 30. 2 It can exist in quantities of 90 to 150, 110 to 140, or 115 to 135.

[0127] In determining the number of fillers 40 in the cross-section described here, firstly, similar to the case of fillers 40 in the primer layer 20, for example, Figure 3A The image shows a cross-sectional SEM image of the functional membrane 1 along its thickness direction. Next, the 0.5 μm section of the functional layer 30 in the SEM image is determined. 2Three ranges (0.796 (μm) × 0.628 (μm)) were defined. Furthermore, using the specified functions of image processing software (product name "ImageJ", manufactured by the National Institutes of Health, USA), the number of circular or approximately circular regions that could be identified as the area occupied by one filler 40 in each of the three ranges was counted, thereby determining the number of filler 40s. The average number of filler 40s in the three ranges was then determined as the average value per 0.5 μm. 2 The number of packing 40s. This will be explained below.

[0128] That is, the number of filler 40 was determined using a scanning electron microscope (SEM), a transmission electron microscope (TEM), or a scanning transmission electron microscope (STEM), and image processing software was used.

[0129] Specifically, a scanning electron microscope (SEM), a transmission electron microscope (TEM), or a scanning transmission electron microscope (STEM) is used to read an image of the cross-section of the functional membrane 1 taken at a resolution of 150 dpi and a magnification of 50,000 using image processing software (product name "ImageJ", manufactured by the National Institutes of Health, USA), and then perform black and white binarization processing. In detail, the following steps (1) to (4) are performed.

[0130] (1) Adjust the number of pixels of the measured image to 640×480.

[0131] (2) Set the actual scale for the image with adjusted pixel count.

[0132] (3) If the image is not an 8-bit grayscale image, convert the image to an 8-bit grayscale image. Then, select "IJ_ISODATA" and "B&W" for automatic binarization to binarize the grayscale image into a black and white image. Then, use "Watershed" to segment overlapping particles.

[0133] (4) Then, the number of packings is determined by using the automatic analysis of “Analize Partcles”.

[0134] Specifically, when determining the number of fillers 40 in functional layer 30, three functional layers 30 are selected from the images following (3) above. Figure 3B The 0.5μm shown 2 The above-described automatic analysis was performed on the range of (0.796(μm) × 0.628(μm)) (Box F1). Furthermore, the average value of the three ranges was determined as the number of fillers 40 in the functional layer 30.

[0135] In determining the number of fillers 40 in the base coating 20, three fillers 40 are selected from the base coating 20 in the images following (3) above. Figure 3B The 0.2μm shown 2 The above-described automatic analysis was performed on the range of (0.796(μm) × 0.251(μm)) (box F2). Furthermore, the average value of the three ranges was determined as the number of fillers 40 in the base coating 20.

[0136] It should be noted that in "Analize Partcles", the size (item: Size) of the parts identified as fillers should be set to 0.0001-0.10 (μm). 2 Additionally, the circularity of the portion identified as filler is set to 0.50-1.0.

[0137] As described above, the size ratio of the aforementioned frames (F1, F2) is not particularly limited and can be arbitrary. For example, when the thickness of the base coating 20 is 0.1 μm, the range of 0.1 μm in length × 2 μm in width can be defined as the second frame F2.

[0138] Figure 3B In the leftmost frame F1, the number of filler 40 particles is 114. The number of filler 40 particles in the central frame F1 is 114. The number of filler 40 particles in the rightmost frame F1 is 106. Furthermore, the average number of particles in these three ranges, 111, is determined to be the number of filler 40 particles per 0.5 μm of functional layer 30. 2 The number of packing materials is 40.

[0139] Additionally, the number of filler 40 particles in the second frame F2 on the left is 33. The number of filler 40 particles in the second frame F2 in the center is 31. The number of filler 40 particles in the second frame F2 on the right is 27. Furthermore, the average number of particles in these three ranges, i.e., 30, is determined to be the number of particles per 0.2 μm of the base coating 20. 2 The number of packing materials is 40.

[0140] In addition, through the above automatic analysis, in Figure 3B The results of determining the area ratio (density) of the filler in each of the boxes F1 and F2 are as follows.

[0141] The density of filler 40 in the first frame F1 on the left is 41.8%. The density of filler 40 in the first frame F1 in the center is 40.5%. The density of filler 40 in the first frame F1 on the right is 39.4%. Furthermore, the average density of these three ranges, 40.6%, was determined to be the density per 0.5 μm of functional layer 30. 2The density of filler 40 is as follows: The density of filler 40 in the second frame F2 on the left is 26.0%. The density of filler 40 in the second frame F2 in the center is 24.0%. The density of filler 40 in the second frame F2 on the right is 20.8%. Furthermore, the average density of the three ranges, 23.6%, was determined to be the density per 0.2 μm of the base coating 20. 2 The packing density is 40.

[0142] Figure 4A and Figure 5A SEM images of a cross-section in the thickness direction of a modified functional membrane are shown. Figure 4A The permeable layer 12 in Figure 3A The permeable layer 12 in the middle is thin. Figure 5A There is no permeable layer 12 in the middle.

[0143] Figure 4B It is shown in Figure 4A The diagram shows the steps for determining the number of filler 40 particles in a cross-section of the SEM image. Figure 5B It is shown in Figure 5A The diagram shows the steps for determining the number of filler 40 particles in a cross-section of the SEM image. Figure 4B and Figure 5B The image shows three boxes (F1, F1) and three boxes (F2, F2). Figure 4B and Figure 5B The results of determining the number and density of filler 40 in the image are as follows.

[0144] Figure 4B In the leftmost frame F1, the number of filler 40 particles is 101. The number of filler 40 particles in the central frame F1 is 109. The number of filler 40 particles in the rightmost frame F1 is 103. Furthermore, the average number of particles across these three ranges, 104, is determined to be the number of filler 40 particles per 0.5 μm of functional layer 30. 2 The number of filler 40s shown.

[0145] Additionally, the number of filler 40 particles in the second frame F2 on the left is 29. The number of filler 40 particles in the second frame F2 in the center is 27. The number of filler 40 particles in the second frame F2 on the right is 25. Furthermore, the average number of particles in these three ranges, 27, is determined to be the number per 0.2 μm of the base coating 20. 2 The number of filler 40s shown.

[0146] in addition, Figure 4BThe density of filler 40 in the first frame F1 on the left is 40.4%. The density of filler 40 in the first frame F1 in the center is 41.9%. The density of filler 40 in the first frame F1 on the right is 38.9%. Furthermore, the average density of these three ranges, 40.4%, was determined to be the density per 0.5 μm of functional layer 30. 2 The packing density is 40.

[0147] Figure 4B The density of filler 40 in the second frame F2 on the left is 33.4%. The density of filler 40 in the second frame F2 in the center is 26.4%. The density of filler 40 in the second frame F2 on the right is 25.5%. Furthermore, the average density of these three ranges, 28.4%, was determined to be the density per 0.2 μm of the base coating 20. 2 The packing density is 40.

[0148] Figure 5B In the leftmost frame F1, the number of filler 40 particles is 111. The number of filler 40 particles in the central frame F1 is 95. The number of filler 40 particles in the rightmost frame F1 is 96. Furthermore, the average number of particles across these three ranges, 101, is determined to be the number of filler 40 particles per 0.5 μm of functional layer 30. 2 The number of filler 40s shown.

[0149] Additionally, the number of filler 40 particles in the second frame F2 on the left is 31. The number of filler 40 particles in the second frame F2 in the center is 22. The number of filler 40 particles in the second frame F2 on the right is 21. Furthermore, the average number of particles in these three ranges, which is 25, is determined to be the number of filler 40 particles per 0.2 μm of the base coating 20. 2 The number of filler 40s shown.

[0150] in addition, Figure 5B The density of filler 40 in the first frame F1 on the left is 36.5%. The density of filler 40 in the first frame F1 in the center is 33.7%. The density of filler 40 in the first frame F1 on the right is 35.3%. Furthermore, the average density of these three ranges, 35.2%, was determined to be the density per 0.5 μm of functional layer 30. 2 The packing density is 40.

[0151] Figure 5B The density of filler 40 in the second frame F2 on the left is 26.0%. The density of filler 40 in the second frame F2 in the center is 19.6%. The density of filler 40 in the second frame F2 on the right is 15.7%. Furthermore, the average density of these three ranges, 20.4%, was determined to be the density per 0.2 μm of the base coating 20. 2 The packing density is 40.

[0152] The following shows the representation in Figure 3B , Figure 4B and Figure 5B Table 1 shows the results of determining the number and density of filler 40.

[0153] [Table 1]

[0154]

[0155] Table 1 shows the values ​​obtained by dividing the average number and average density of fillers 40 in the base coat 20 by the average number and average density of fillers 40 in the functional layer 30. The ratio of the average number of fillers 40 in the base coat 20 to the average number of fillers 40 in the functional layer 30, in the order of left, center, and right, is 0.27, 0.26, and 0.25. In other words, the number of fillers 40 in the base coat 20 is approximately one-quarter of the number of fillers 40 in the functional layer 30. Figure 3B , Figure 4B , Figure 5B The functional layers 30 in the functional membrane all exhibit good adhesion. Based on this result, it can be inferred that if the number of fillers 40 in the base layer 20 is more than 1 / 5 and less than 1 / 3 of the number of fillers 40 in the functional layers 30, the adhesion of the functional layers 30 will become even better.

[0156] Furthermore, the average density of the filler 40 in the base coating 20 / the average density of the filler 40 in the functional layer 30, in the order of left, center, and right, is 0.58, 0.70, and 0.58 respectively. In other words, the density of the filler 40 in the base coating 20 is approximately 1 / 2 to 3 / 4 of the number of fillers 40 in the functional layer 30. Based on this result, it is inferred that if the density of the filler 40 in the base coating 20 is more than 1 / 2 and less than 3 / 4 of the density of the filler 40 in the functional layer 30, the adhesion of the functional layer 30 becomes good. It should be noted that the inventors of this application have also confirmed that if the density of the filler 40 in the base coating 20 is more than 1 / 3 of the density of the filler 40 in the functional layer 30, good adhesion can be obtained.

[0157] <Manufacturing Methods of Functional Membranes>

[0158] Next, an example of a method for manufacturing the functional membrane 1 will be described.

[0159] Figure 6 This is a flowchart illustrating the manufacturing method of functional membrane 1. Figure 7 This shows the implementation Figure 6 A diagram of an example of the manufacturing equipment 100 for the manufacturing method of the functional membrane 1 described herein.

[0160] exist Figure 6In the manufacturing method of the functional membrane 1 shown, the steps of diluent coating (S61), drying (S62), setting (S63), and curing (S64) are performed sequentially. It should be noted that... Figure 6 The diagram schematically illustrates the state of the substrate 10 and the layers formed on the substrate 10 corresponding to each process. Each process will be described in detail below.

[0161] (Diluent coating process)

[0162] In the diluent coating process performed in step S61, a diluent prepared by diluting the resin composition with a solvent is coated onto the substrate 10. The diluent coating can be performed, for example, using a gravure roller or a dip coater. In this embodiment, the resin composition, as described above, is a polymerizable resin composition, for example, a resin composition containing a resin material that is ionizing radiation-curable, and more specifically, ultraviolet-curable. Additionally, the resin composition also contains filler 40.

[0163] The solvent may be, for example, a ketone solvent composed of one or more of acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), etc., or a mixture of MEK and MIBK. The solvent in 100 parts by mass of the diluent is, for example, 40 to 99 parts by mass, and the resin composition is 1 to 60 parts by mass. The remainder of the solvent in the diluent constitutes the resin composition.

[0164] In this embodiment, as described above, by applying the diluent to the surface of the substrate 10, the solvent in the diluent penetrates from the surface of the substrate 10 into the interior of the substrate 10, causing the substrate 10 to swell. At this time, the resin composition in the diluent also penetrates into the substrate 10 (12'). Subsequently, the solvent is evaporated in the drying process (S62) and the resin composition is cured in the curing process (S64), thereby forming the permeation layer 12.

[0165] From the perspective of reliably forming the permeation layer 12, it is preferable that the solvent easily penetrates into the substrate 10, which is mainly composed of resin, and the solvent preferably has high resin solubility. Polar solvents such as alcohols, ketones, ethers, esters, and chlorines generally have high resin solubility, so ketone solvents and ester solvents are preferred from the perspective of forming the permeation layer 12, and particularly preferred from the perspective of forming the permeation layer 12. However, non-polar solvents such as hydrocarbons can also be used as solvents.

[0166] As described above, the thickness of the base coating 20 is preferably 0.1 μm or more and 1.0 μm or less, but considering drying, condensation, polymerization, etc., the thickness of the diluent coated on the substrate 10 is preferably 3 μm or more and 30 μm or less.

[0167] (Drying process)

[0168] In the drying process performed in step S62, the diluent on the substrate 10 is dried, causing some or all of the solvent in the diluent to evaporate, and the resin composition in the diluent is kept in an uncured or semi-cured state. Drying can be performed by passing the substrate 10 through a drying oven 103 equipped with a heater, or by natural drying. It should be noted that when the resin composition is in a semi-cured state, an ultraviolet irradiation process (semi-curing treatment process) can be performed during this drying process, or an ultraviolet irradiation process (semi-curing treatment process) can be performed before the drying process. It should be noted that, as described as "causing some or all of the solvent in the diluent to evaporate," drying refers to the evaporation of a portion or all of the liquid component.

[0169] In this embodiment, a portion of the solvent is evaporated, intentionally leaving residual solvent in the diluent. Furthermore, the resin composition in the diluent is in an uncured state. In this embodiment, a functional film 1 is fabricated where the density of the filler 40 in the base layer 20 is less than the density of the filler 40 in the functional layer 30. In this case, if residual solvent remains in the diluent and the resin composition remains uncured, the density of the filler 40 in the base layer 20 is likely to be less than the density of the filler 40 in the functional layer 30. For this reason, residual solvent remains and the resin composition remains uncured.

[0170] However, even when a portion of the solvent evaporates and the resin composition is partially cured, or when all the solvent evaporates and the resin composition is not cured, the density of the filler 40 in the base coat 20 may sometimes be less than the density of the filler 40 in the functional layer 30. A simple solution is to reduce the amount of filler in the diluent. On the other hand, if it is desirable to have the same density of the filler 40 in the base coat 20 and the filler 40 in the functional layer 30, the solvent can be completely evaporated, and the resin composition can be partially cured.

[0171] (Setting up the process)

[0172] In the setting step S63, a resin composition for forming the functional layer 30 is set onto the diluted liquid after the drying step. The method of setting the resin composition is not particularly limited; it can be applied from a die. In this embodiment, the diluted liquid after the drying step is viscous due to the evaporation of at least a portion of the solvent.

[0173] In this embodiment, the resin composition used in the setting process is the same substance as the resin composition diluted with solvent in the diluent coating process. Furthermore, in this embodiment, the heated resin composition is set onto the diluent. Therefore, the density of the filler 40 in the base layer 20 is easily less than the density of the filler 40 in the functional layer 30. It should be noted that, needless to say, in this embodiment, the proportion of filler 40 in the resin composition used in the setting process is the same as the proportion of filler 40 in the resin composition used in the diluent coating process.

[0174] In this embodiment, when the resin composition is placed on the diluent, a portion of the resin composition placed on the diluent can be made to flow towards the diluent side by utilizing the residual solvent in the diluent. This phenomenon is promoted when the resin solubility in the diluent is high; from this perspective, ketone-based solvents are preferred as solvents. Furthermore, when the resin composition is heated, a portion of the resin composition easily flows towards the diluent side. At this time, the residual solvent evaporates and replaces the resin composition, thereby enabling a state where the density of the filler 40 in the base layer 20 is less than the density of the filler 40 in the functional layer 30 when the resin composition is subsequently cured. It should be noted that in this embodiment, the filler 40 in the functional layer 30 tends to form a state where many adjacent fillers are in contact with each other, and it does not have the property of being easily attracted by solvents, therefore it is essentially not introduced into the diluent side.

[0175] (Curing process)

[0176] Then, in the curing process performed in step S64, a base coating 20 containing a resin cured from the resin composition is formed on the substrate 10 by curing the resin composition neutralized in the diluent, and a functional layer 30 containing a resin cured from the resin composition is formed on the base coating 20. The curing of the resin composition is performed, for example, by irradiation with ultraviolet light.

[0177] As described above, in this embodiment, a portion of the resin composition disposed on the diluent is allowed to flow towards the diluent side using the residual solvent in the diluent. At this time, the residual solvent evaporates and replaces the resin composition. In this state, the resin composition is cured by ultraviolet light, thereby obtaining a state where the density of the filler 40 in the base layer 20 is less than the density of the filler 40 in the functional layer 30. As described above, in this embodiment, a functional film 1 is manufactured, but an additional curing step (ultraviolet irradiation) can also be performed after this curing step. It should be noted that during the curing step, the resin composition can be cured while a pattern is formed on the resin composition in the diluent using a mold.

[0178] (Manufacturing equipment)

[0179] Figure 7The manufacturing equipment 100 shown includes a supply roller 101, a gravure roller 102, a drying oven 103, a die head 104, a first UV curing device 105, and a take-up roller 106.

[0180] The supply roller 101 winds the substrate 10, feeding the substrate 10 toward the gravure roller 102. The gravure roller 102 coats the substrate 10 by transferring the diluent onto the substrate 10. The drying oven 103 heats the substrate 10 with the diluent, which has been transported inside, using a heater to dry the diluent. The die head 104 coats the heated resin composition onto the diluent on the substrate 10 after passing through the drying oven 103. The first UV curing apparatus 105 cures the resin composition by irradiating it with ultraviolet light from the side opposite to the resin composition side, across the substrate 10, while forming a pattern on the resin composition using a roller 105A with a die. Then, the take-up roller 106 sequentially winds up the functional film 1.

[0181] In the manufacturing equipment 100 described above, a diluent coating process is performed using a gravure roller 102. A drying process is then performed in a drying oven 103. A setting process is performed using a die head 104. Finally, a curing process is performed using a first UV curing device 105. It should be noted that the manufacturing equipment for the functional film 1 may differ from the manufacturing equipment 100 described above. Of course, the manufacturing process and equipment vary depending on the material used to form the functional film.

[0182] The functional film 1 of this embodiment described above includes a substrate 10, a base coating 20 disposed on the substrate 10, and a functional layer 30 disposed on the base coating 20. The base coating 20 includes filler 40, and the functional layer 30 also includes filler 40. Thus, the base coating 20 improves the adhesion between the substrate 10 and the functional layer 30, while the filler 40 in the base coating 20 and the filler 40 in the functional layer 30 perform the desired function. Therefore, the adhesion between the substrate 10 and the functional layer 30 can be improved simply and effectively, thereby enabling the desired function to be appropriately performed.

[0183] In particular, in this embodiment, the density of filler 40 in the base coating 20 is less than the density of filler 40 in the functional layer 30. This reduces the amount of filler 40 in the base coating 20 that contacts the substrate 10, thus improving the adhesion between the substrate 10 and the base coating 20. Furthermore, the increased contact area between resin 21 and resin 31 between the base coating 20 and the functional layer 30 further enhances the adhesion between the base coating 20 and the functional layer 30.

[0184] In this embodiment, the base coat 20 and the functional layer 30 contain the same resin. In this case, the resin 21 of the base coat 20 and the resin 31 of the functional layer 30 form the same interface, and the base coat 20 and the functional layer 30 can be partially or completely fused at the interface. Consequently, the coefficients of linear expansion of the base coat 20 and the functional layer 30 are the same, approximately the same, or close. This improves the adhesion between the base coat 20 and the functional layer 30, resulting in improved adhesion between the substrate 10 and the functional layer 30. Furthermore, since the resin 21 of the base coat 20 and the resin 31 of the functional layer 30 are the same, the forming material of the base coat 20 can be the same as the forming material of the functional layer 30, making it readily available. This allows for a simple and effective improvement in the adhesion between the substrate 10 and the functional layer 30. It should be noted that the resin composition forming the base coat 20 corresponds to the first resin composition, and the resin composition constituting the functional layer 30 corresponds to the second resin composition. In this embodiment, the first resin composition and the second resin composition are the same composition, but they can also be different compositions.

[0185] Furthermore, the substrate 10 has a permeation layer 12 formed by the resin contained in the base coating 20 permeating to a portion of its side. This effectively improves the adhesion between the substrate 10 and the functional layer 30.

[0186] More specifically, the functional membrane 1 of this embodiment has the following configuration (1) or configuration (2).

[0187] <Composition (1)>

[0188] The functional membrane 1 comprises a substrate 10 containing an acetylcellulose-based resin, a base coating 20 containing a filler 40 disposed on the substrate 10, and a functional layer 30 containing the filler 40 disposed on the base coating 20. The substrate 10 has a permeable layer 12 on the base coating 20 side, formed by the resin contained in the base coating 20 permeating to a portion thereof, and the thickness of the permeable layer 12 is 0.1 μm to 3.5 μm. The thickness of the base coating 20 is 0.1 μm to 1.0 μm. The filler 40 in the base coating 20 and the filler 40 in the functional layer 30 are silica particles with an average particle size of 20 nm to 80 nm. The density of the filler 40 in the base coating 20 is 1 / 3 to 3 / 4 of the density of the filler 40 in the functional layer 30. The base coating 20 and the functional layer 30 each contain a resin, and the resin contained in the base coating 20 is the same as the resin contained in the functional layer 30.

[0189] <Composition (2)>

[0190] The functional membrane 1 comprises a substrate 10 containing an acetylcellulose-based resin, a base coating 20 containing a filler 40 disposed on the substrate 10, and a functional layer 30 containing the filler 40 disposed on the base coating 20. The substrate 10 has a permeable layer 12 on the base coating 20 side, formed by the resin contained in the base coating 20 permeating to a portion thereof, and the thickness of the permeable layer 12 is 0.1 μm to 3.5 μm. The thickness of the base coating 20 is 0.1 μm to 1.0 μm. The filler 40 in the base coating 20 and the filler 40 in the functional layer 30 are silica particles with an average particle size of 20 nm to 80 nm. The filler 40 in the functional layer 30 is distributed in sections along the thickness direction of the functional layer 30 at intervals of 0.5 μm. 2 The number of fillers 40 in the base coating 20 is between 90 and 150. The filler 40 in the base coating 20 is distributed in sections along the thickness direction of the base coating 20 at intervals of 0.2 μm. 2 The number of components is between 15 and 45. The base coating 20 and the functional layer 30 each contain a resin, and the resin contained in the base coating 20 is the same as the resin contained in the functional layer 30.

[0191] According to the above-described configurations (1) and (2), the adhesion between the substrate 10 and the functional layer 30 can be improved simply and extremely effectively, thereby enabling the desired function to be performed appropriately, which is particularly advantageous when good optical function is desired. Furthermore, in this embodiment, the base coating 20 forms a permeation layer 12 on the substrate 10, which can bond to the substrate 10 through anchoring effect and intermolecular attraction, and is compatible with and simultaneously cured with the resin of the functional layer 30, thereby enabling bonding through anchoring effect, intermolecular attraction, and chemical bonds. Thus, extremely good adhesion is obtained. It should be noted that the bonding state described above may not necessarily occur, and such bonding state does not limit the present invention. Additionally, the above-described configurations (1) and (2) correspond to an example configuration in the present invention, namely, the base coating 20 contains one resin and the functional layer 30 contains one resin, and the resin composition of the base coating 20 and the resin composition of the functional layer 30 are only one (single) resin, which is the same.

[0192] <Variation Example>

[0193] The following describes variations of the functional membrane. Figures 8 to 10 Functional membranes 2 to 4 of the modified examples are shown schematically. The same reference numerals are used to denote the same components as in the embodiments described above in the following modified examples, thus omitting the description.

[0194] Figure 8In addition to the substrate 10, the base coating 20, and the functional layer 30 described in the above embodiments, the functional film 2 also includes a first additional functional layer 50 and a surface protective layer 60. The first additional functional layer 50 is disposed on the functional layer 30, and the surface protective layer 60 is disposed on the first additional functional layer 50.

[0195] To be precise, the first additional functional layer 50 is configured to be in direct contact with the side opposite to the base layer 20 of one pair of opposing functional layers 30 in the thickness direction. The surface protective layer 60 is configured to be in direct contact with the side opposite to the functional layer 30 of one pair of opposing first additional functional layers 50 in the thickness direction.

[0196] The function of the first additional functional layer 50 is not particularly limited. For example, it can provide optical functions such as anti-glare and anti-reflection, hard coating, gas barrier, conductivity assurance, magnetic assurance, abrasion resistance, heat insulation, flame retardancy, and UV blocking. The material of the first additional functional layer 50 can be organic materials, inorganic materials, or a combination of both. The surface protective layer 60 constitutes the outermost surface of the functional film 2.

[0197] Figure 9 The functional membrane 3 shown has a substrate 10, a base coating 20 disposed on the substrate 10, and a functional layer 30 disposed on the base coating 20, but differs from the above embodiment in that the base coating 20 does not contain filler 40.

[0198] In this modified example of the functional film 3, the resin 21 contained in the base coating 20 and the resin 31 contained in the functional layer 30 are the same resin. Therefore, the resin 21 of the base coating 20 and the resin 31 of the functional layer 30 form the same interface, and the base coating 20 and the functional layer 30 can be partially or completely fused at the interface, resulting in the base coating 20 and the functional layer 30 having the same or approximately the same coefficient of linear expansion. As a result, the adhesion between the base coating 20 and the functional layer 30 is improved, and consequently, the adhesion between the substrate 10 and the functional layer 30 is improved.

[0199] When manufacturing the functional membrane 3 of this modified example, Figure 6 In the diluent coating process shown, a resin composition without filler 40 is used. On the other hand, in the setting process, the resin composition set on the dried diluent contains filler 40. However, the composition of the resin composition used in the setting process after removing filler 40 is the same as that of the resin composition diluted with the diluent in the diluent coating process. In addition, in this modified example, in the drying process, by leaving residual solvent in the diluent, or by leaving the resin composition uncured, or by heating the resin composition in the setting process, a flow phenomenon of the resin composition can be appropriately generated.

[0200] in addition, Figure 10 The functional membrane 4 shown has a substrate 10, a base coating 20 disposed on the substrate 10, and a functional layer 30 disposed on the base coating 20, but the base coating 20 and the functional layer 30 do not contain filler 40.

[0201] In this modified example of the functional film 4, the resin 21 contained in the base coating 20 and the resin 31 contained in the functional layer 30 are the same resin. Therefore, the resin 21 of the base coating 20 and the resin 31 of the functional layer 30 form the same interface, and the base coating 20 and the functional layer 30 can be partially or completely fused at the interface, resulting in the base coating 20 and the functional layer 30 having the same or approximately the same coefficient of linear expansion. As a result, the adhesion between the base coating 20 and the functional layer 30 is improved, and consequently, the adhesion between the substrate 10 and the functional layer 30 is improved.

[0202] When manufacturing the functional membrane 4 of this modified example, Figure 6 In the diluent coating process shown, a resin composition without filler 40 is used. Furthermore, in the setting process, the resin composition set onto the dried diluent also does not contain filler 40. Moreover, the resin composition used in the diluent coating process is the same as the resin composition used in the setting process. Additionally, in the drying process, by leaving residual solvent in the diluent, allowing the resin composition to remain uncured, or by heating the resin composition in the setting process, a suitable flow phenomenon of the resin composition can be generated.

[0203] Example

[0204] Next, examples of manufacturing the functional membranes according to the above embodiments, comparative examples, and evaluation results comparing these properties will be described.

[0205] (Example 1)

[0206] The functional membrane of Example 1 comprises a substrate 10, a base coating 20 disposed on the substrate 10, and a functional layer 30 disposed on the base coating 20. The base coating 20 and the functional layer 30 contain the same resin. That is, the base coating 20 and the functional layer 30 are formed by polymerizing the same resin composition. Furthermore, the resin composition contains a filler 40. The base coating 20 and the functional layer 30 are formed such that the density of the filler 40 in the base coating 20 is less than the density of the filler 40 in the functional layer 30. Additionally, a permeation layer 12 is formed on the substrate 10.

[0207] The details of the forming materials of each part in Example 1 are as follows.

[0208] • Substrate 10 is a TAC film with a thickness of 80 μm.

[0209] The resin composition is an ionizing radiation-curable resin containing filler 40. More specifically, the resin composition is pentaerythritol tri(meth)acrylate.

[0210] • Filler 40 consists of silica particles. The average particle size of the silica particles is 65 nm.

[0211] • The solvent for diluting the resin composition is a mixture of MEK and MIBK.

[0212] (Example 2)

[0213] The functional film of Example 2 is the same as that of Example 1, except that the density of filler 40 in the base layer 20 is the same as the density of filler 40 in the functional layer 30.

[0214] (Comparative Example)

[0215] The comparative example functional membrane was formed by directly depositing a resin composition containing filler onto a substrate and then curing it. That is, the comparative example functional membrane does not have a permeation layer or a base layer. The materials of the substrate, filler, and resin composition are the same as in Examples 1 and 2.

[0216] (Evaluation Results)

[0217] The functional films used as examples and comparative examples were evaluated for their adhesion using a cross-cut test. Specifically, according to JIS K5600-5-6:1999, a checkerboard pattern of 100 square cuts (1 mm each) was created on the surface of each functional film using a cross-cutting CCJ-1 (manufactured by COTEC). A 24 mm wide industrial cellotape (registered trademark) manufactured by NICHIBAN Co., Ltd. was applied to the checkerboard pattern, and the film was rubbed back and forth 10 times with a scraper to achieve adhesion. The film was then quickly peeled off at a 150° angle. This process was repeated 5 times, and the number of remaining squares was counted. The remaining number of squares was used as the numerator, and the total number of squares was used as the denominator for evaluation. In this evaluation, a higher number of remaining squares indicates better adhesion. Furthermore, this evaluation was conducted in the initial state immediately after manufacturing the functional films and after 300 temperature cycles between -40°C and 85°C.

[0218] The evaluation results are shown in the table below.

[0219] [Table 2]

[0220]

[0221] In Example 1, all 100 cells remained in both the initial state and after the temperature cycling test. In Example 2, all 100 cells remained in the initial state, and 98 cells remained after the temperature cycling test. On the other hand, in the comparative example, all 100 cells peeled off in both the initial state and after the temperature cycling test. That is, all 100 cells were functional layers peeled off from the substrate.

[0222] The evaluation results confirm that the functional membrane of the embodiment has high adhesion. In particular, it was also confirmed that the adhesion is further improved when the density of the filler 40 in the base layer 20 is less than the density of the filler 40 in the functional layer 30.

[0223] The above describes the embodiments and examples of the present invention, but various modifications can be made to the above embodiments. Such modifications are also included within the technical scope of the present invention.

Claims

1. A functional membrane comprising: A substrate containing acetylcellulose-based resins; A filler-containing undercoat layer disposed on the substrate; and A filler-containing functional layer disposed on the base coating. The substrate has a permeation layer formed by the resin contained in the base coating permeating a portion of the base coating on the base coating side, the thickness of the permeation layer being 0.1 μm to 3.5 μm. The thickness of the base coating is between 0.1 μm and 1.0 μm. The filler in the base coating and the filler in the functional layer are silica particles with an average particle size of 20 nm to 80 nm. The density of the filler in the base coating layer is more than 1 / 3 and less than 3 / 4 of the density of the filler in the functional layer. The base coating and the functional layer each contain resin, and the resin composition of the base coating is the same as that of the functional layer.

2. A functional membrane, comprising: A substrate containing acetylcellulose-based resins; A filler-containing undercoat layer disposed on the substrate; and A filler-containing functional layer disposed on the base coating. The substrate has a permeation layer formed by the resin contained in the base coating permeating a portion of the base coating on the base coating side, the thickness of the permeation layer being 0.1 μm to 3.5 μm. The thickness of the base coating is between 0.1 μm and 1.0 μm. The filler in the base coating and the filler in the functional layer are silica particles with an average particle size of 20 nm to 80 nm. The filler in the functional layer is spaced at intervals of 0.5 μm in the cross-section along the thickness direction of the functional layer. 2 The number exists in quantities between 90 and 150. The filler in the base coating is spaced at 0.2 μm intervals in the cross-section along the thickness direction of the base coating. 2 The number exists in quantities between 15 and 45. The base coating and the functional layer each contain resin, and the resin composition of the base coating is the same as that of the functional layer.

3. A functional membrane, comprising: A substrate containing acetylcellulose-based resins; A filler-containing undercoat layer disposed on the substrate; and A filler-containing functional layer disposed on the base coating. The substrate has a permeation layer formed by the resin contained in the base coating permeating a portion of the base coating on the base coating side, the thickness of the permeation layer being 0.1 μm to 3.5 μm. The thickness of the base coating is between 0.1 μm and 1.0 μm. The filler in the base coating and the filler in the functional layer are silica particles with an average particle size of 20 nm to 80 nm. The filler in the base coating is spaced at 0.2 μm intervals in the cross-section along the thickness direction of the base coating. 2 The number exists in quantities between 15 and 45. The base coating and the functional layer each contain resin, and the resin composition of the base coating is the same as that of the functional layer.

4. A functional membrane, comprising: A substrate containing acetylcellulose-based resins; A filler-containing undercoat layer disposed on the substrate; and A filler-containing functional layer disposed on the base coating. The substrate has a permeation layer formed by the resin contained in the base coating permeating a portion of the base coating on the base coating side, the thickness of the permeation layer being 0.1 μm to 3.5 μm. The thickness of the base coating is between 0.1 μm and 1.0 μm. The filler in the base coating and the filler in the functional layer are silica particles with an average particle size of 20 nm to 80 nm. The density of the filler in the base coating is more than 15% and less than 30% in the cross-section along the thickness direction of the base coating. The base coating and the functional layer each contain resin, and the resin composition of the base coating is the same as that of the functional layer.

5. A method for manufacturing a functional membrane, comprising: The diluent coating process involves coating a substrate with a diluent prepared by diluting a first resin composition containing fillers with a solvent. The drying process evaporates a portion of the solvent, leaving the first resin composition in an uncured or semi-cured state. The setting process involves setting a second resin composition containing filler onto the diluent; and The curing process involves curing the first resin composition and the second resin composition to form a base coating containing the cured resin of the first resin composition on the substrate, and then forming a functional layer containing the cured resin of the second resin composition on the base coating. In the diluent coating process, a portion of the first resin composition in the diluent is allowed to penetrate into the substrate. In the drying process, a portion of the solvent is evaporated, thereby leaving residual solvent in the diluted solution. During the setting process, when the second resin composition is placed on the diluent, the residual solvent is used to cause a portion of the second resin composition on the diluent to flow towards the diluent side. The density of the filler in the base coating layer is less than the density of the filler in the functional layer. The filler contained in the first resin composition is the same as the filler contained in the second resin composition.

6. The method for manufacturing the functional membrane as described in claim 5, wherein, In the setting process, the heated second resin composition is placed on the diluent.

7. The method for manufacturing the functional membrane as described in claim 5, wherein, The proportion of the filler in the first resin composition is the same as the proportion of the filler in the second resin composition.

8. The method for manufacturing the functional membrane as described in claim 5, wherein, The solvent is a ketone solvent.

9. The method for manufacturing the functional membrane as described in claim 5, wherein, The filler is silica particles with an average particle size of 20 nm to 80 nm.

10. The method for manufacturing the functional membrane as described in claim 5, wherein, The first resin composition and the second resin composition are ionizing radiation-curable resins or thermosetting resins.

11. The method for manufacturing the functional membrane as described in claim 5, wherein, The substrate comprises acetylcellulose-based resin.

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