Film and method for manufacturing the same, laminated film, and display

Abstract

One embodiment of the present invention is a single-layer film composed of a layer of a cured product of a composition including a polyorganosiloxane compound having an epoxy group. The polyorganosiloxane compound is a condensate of a silane compound represented by general formula (1). R1 is a C1-16 substituted or unsubstituted alkylene group; R2 is a hydrogen atom or a C1-10 alkyl group; R3 is a hydrogen atom or a monovalent hydrocarbon group selected from C1-10 alkyl groups, C6-25 aryl groups, and C7-12 aralkyl groups; x is an integer of 2 or 3; and Y is a glycidyloxy group or an alicyclic epoxy group.　Y-R1-(Si(OR2)xR3 3-x) … (1)

Description

[Technical Field]

[0001] The present invention relates to a single-layer film formed of a cured product of a composition and applications thereof. [Background Art]

[0002] With the rapid progress of electronic devices such as displays, touch panels and solar cells, there are demands for thinner, lighter, and furthermore flexible devices. In response to these demands, replacement of glass materials used for substrates, cover windows and the like with plastic film materials has been studied. For example, Patent Document 1 and Patent Document 2 propose using a hard coat film in which a hard coat layer formed of a cured product of a curable resin composition is provided on a film substrate as a cover window material for a display. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 2015-69197 [Patent Document 2] International Publication No. 2020 / 040209 [Summary of the Invention] [Problems to be Solved by the Invention]

[0004] Curved displays and foldable displays have been developed, and cover windows for these displays are required to have flexibility in addition to surface hardness. Furthermore, in a foldable display, when the screen is changed from a bent state (bent state) to a flat state, it is required that bending marks are unlikely to remain in the bent portion and the restorability is excellent.

[0005] A hard coat film obtained by providing a hard coat layer in contact with a film substrate tends to leave bending marks and has a problem in restoration properties. An object of the present invention is to provide a film excellent in bending restoration properties. [Means for Solving the Problem]

[0006] One embodiment of the present invention is a single-layer film consisting of a cured product layer of a composition containing a polyorganosiloxane compound having an epoxy group. The thickness of the film may be 40 to 120 µm.

[0007] The polyorganosiloxane compound having an epoxy group is a condensate of a silane compound represented by the following general formula (1). Y-R 1 -(Si(OR 2 ) x R 3 3-x ) …(1)

[0008] In general formula (1), R 1 is a substituted or unsubstituted alkylene group having 1 to 16 carbon atoms; R 2 is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; R 3 is a hydrogen atom or a monovalent hydrocarbon group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 25 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms; x is an integer of 2 or 3; and Y is a glycidyloxy group or an alicyclic epoxy group.

[0009] In the silane compound represented by general formula (1), R 1 may be a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms, and Y may be an alicyclic epoxy group. In the silane compound represented by general formula (1), R 1 may be a substituted or unsubstituted alkylene group having 4 to 16 carbon atoms, and Y may be a glycidyloxy group.

[0010] The above single-layer film is obtained by coating a substrate with a composition containing a polyorganosiloxane compound, irradiating it with active energy rays to cure the composition on the substrate and form a cured layer, and then peeling the cured layer from the substrate. Preferably, the substrate has a water contact angle of 74 to 107° on the surface to which the composition is coated.

[0011] A film consisting of the cured material layer described above may be bonded to another transparent resin film via an adhesive layer to form a laminated film. A double-sided adhesive sheet is preferred as the adhesive layer for bonding the film consisting of the cured material layer to the transparent resin film. The thickness of the transparent resin film may be 50 μm or less.

[0012] The above-mentioned film and laminated film can be used as a cover window positioned on the viewing surface of the image display panel. The display may also be a foldable display. [Effects of the Invention]

[0013] Compared to hard-coat films, the above-mentioned film is less prone to retaining bend marks and has superior bending recovery properties. [Brief explanation of the drawing]

[0014] [Figure 1] This is a cross-sectional view of a laminate in which a cured material layer is tightly laminated on a substrate. [Figure 2] This figure shows the state after the substrate and cured layer of the laminate in Figure 1 have been separated. [Figure 3] This is a cross-sectional view of a laminated body according to one embodiment. [Modes for carrying out the invention]

[0015] One embodiment of the present invention is a single-layer film consisting of a cured layer obtained by curing a curable composition. By applying the curable composition onto a substrate 1 and curing the composition, a laminate 10 is obtained in which a cured film (cured layer) 3 is closely laminated on the substrate 1, as shown in Figure 1. By peeling off the substrate 1 from this laminate 10, a film 3 consisting of a single-layer cured layer that is not laminated with other films, etc., is obtained, as shown in Figure 2.

[0016] [Curable composition] The curable composition contains a polyorganosiloxane compound containing epoxy groups as a curable resin component. Such curable compositions are disclosed in WO2014 / 204010, WO2016 / 098596, WO2018 / 096729, WO2020 / 040209, Japanese Patent Publication No. 2016-193956, Japanese Patent Publication No. 2017-8142, etc., and these descriptions can be referred to and invoked. Preferably, the curable composition contains a photocationic polymerization initiator in addition to the polyorganosiloxane compound as a curable resin component.

[0017] <Polyorganosiloxane compounds> Polyorganosiloxane compounds containing epoxy groups are obtained by condensation of silane compounds containing epoxy groups.

[0018] (Silane compounds) Silane compounds containing an epoxy group are represented by the following general formula (1). YR 1 -(Si(OR 2 ) x R 3 3-x ) …(1)

[0019] R 1 R is a substituted or unsubstituted alkylene group having 1 to 16 carbon atoms. 2 R is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. 3x is a hydrogen atom, or a monovalent hydrocarbon group selected from C1-C10 alkyl groups, C6-C25 aryl groups, and C7-C12 aralkyl groups. x is an integer of 2 or 3. Y is a monovalent organic group containing an epoxy group.

[0020] Silane compounds represented by general formula (1) have 2 or 3 (-OR) in one molecule. 2 ) has Si-OR 2 It is hydrolyzable. Si-OR 2 After hydrolysis, condensation occurs to produce polyorganosiloxane compounds, which are condensates of silane compounds.

[0021] R 1 Specific examples include unsubstituted linear alkylenes such as methylene group, diethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, decamethylene group, dodecamethylene group, tetradecamethylene group, and hexadecamethylene group. 1 It may further have substituents having 1 to 6 carbon atoms. Examples of substituents include methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclohexyl, and phenyl groups. From the viewpoint of the flexibility of the cured product, R 1 Unsubstituted linear alkylenes are preferred.

[0022] R 1 The number of carbon atoms (chain length of alkylene) can affect the hardness and flexural resistance of the cured film, and when the number of carbon atoms is 17 or more, the surface hardness of the cured film tends to decrease. From the perspective of increasing surface hardness such as pencil hardness, R 1 The number of carbon atoms is preferably 1 to 3. On the other hand, from the viewpoint of improving the flexibility and bending recovery of the cured film, R 1 The number of carbon atoms is preferably 4 to 16.

[0023] R 2Preferably, R is an alkyl group, and specific examples include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, isopropyl group, isobutyl group, cyclohexyl group, ethylhexyl group, etc. From the viewpoint of hydrolysis, 2 The group is preferably a methyl group, an ethyl group, or a propyl group, and most preferably a methyl group.

[0024] R 3 When x is a hydrocarbon group, specific examples include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, isopropyl, isobutyl, cyclohexyl, ethylhexyl, benzyl, phenyl, tolyl, xylyl, naphthyl, and phenethyl groups. Note that in general formula (1), when x is 3, the silane compound is R 3 It does not possess.

[0025] Specific examples of the organic group Y containing an epoxy group include the glycidyloxy group represented by the following formula and alicyclic epoxy groups. The 3,4-epoxycyclohexyl group is preferred as the alicyclic epoxy group.

[0026] [ka]

[0027] When Y is an alicyclic epoxy group, the cured film tends to have high surface hardness. When Y is a glycidyloxy group, the cured product tends to have excellent flexibility.

[0028] When Y is an alicyclic epoxy group, from the viewpoint of increasing the surface hardness of the cured film, R in general formula (1) 1 It is preferable that it is an alkylene group having 1 to 3 carbon atoms.

[0029] In general formula (1), R 1Specific examples of silane compounds in which is an alkylene group having 1 to 3 carbon atoms and Y is a 3,4-epoxycyclohexyl group include (3,4-epoxycyclohexyl)methyldimethoxysilane, (3,4-epoxycyclohexyl)dimethylmethoxysilane, (3,4-epoxycyclohexyl)triethoxysilane, (3,4-epoxycyclohexyl)methyldiethoxysilane, (3,4-epoxycyclohexyl)dimethylethoxysilane, {(3,4-epoxy methyldimethoxysilane}. {(3,4-epoxycyclohexyl)methyl}trimethoxysilane, {(3,4-epoxycyclohexyl)methyl}methyldimethoxysilane, {(3,4-epoxycyclohexyl)methyl}dimethylmethoxysilane, {(3,4-epoxycyclohexyl)methyl}triethoxysilane, {(3,4-epoxycyclohexyl)methyl}methyldiethoxysilane, {(3,4-epoxycyclohexyl)methyl}dimethylethoxysilane, {2-(3,4-epoxycyclohexyl) {Ethyl}trimethoxysilane, {2-(3,4-epoxycyclohexyl)ethyl}methyldimethoxysilane, {2-(3,4-epoxycyclohexyl)ethyl}dimethylmethoxysilane, {2-(3,4-epoxycyclohexyl)ethyl}triethoxysilane, {2-(3,4-epoxycyclohexyl)ethyl}methyldiethoxysilane, {2-(3,4-epoxycyclohexyl)ethyl}dimethylethoxysilane, {3-(3,4-epoxycyclo Examples include {3-(3,4-epoxycyclohexyl)propyl}trimethoxysilane, {3-(3,4-epoxycyclohexyl)propyl}methyldimethoxysilane, {3-(3,4-epoxycyclohexyl)propyl}dimethylmethoxysilane, {3-(3,4-epoxycyclohexyl)propyl}triethoxysilane, {3-(3,4-epoxycyclohexyl)propyl}methyldiethoxysilane, and {3-(3,4-epoxycyclohexyl)propyl}dimethylethoxysilane.

[0030] When Y is a glycidyloxy group, from the viewpoint of improving the flexibility and bending recovery of the cured film, R in general formula (1) 1 It is preferable that it is an alkylene group having 4 to 16 carbon atoms. 1Because the carbon number is 4 or more, the distance between the epoxy group and the silicon atom is long. As a result, even after the polyorganosiloxane compound hardens due to the reaction of the epoxy group, the molecular structure remains flexible, and the hardened film exhibits excellent flex resistance and bending recovery.

[0031] The greater the distance between the Si atom and the epoxy group, i.e., the more the alkylene group R acts as a spacer. 1 The larger the number of carbon atoms and the longer the chain length, the more the flexibility of the cured film tends to improve. 1 The number of carbon atoms may be 6 or more, or 8 or more. As mentioned above, R 1 If the number of carbon atoms is excessively large, the surface hardness of the cured film tends to decrease. 1 The number of carbon atoms is preferably 14 or less, and more preferably 12 or less.

[0032] In general formula (1), R 1Specific examples of silane compounds in which C1 is an alkylene group having 4 to 16 carbon atoms and Y is a glycidyloxy group include 4-glycidyloxybutyltrimethoxysilane, 4-glycidyloxybutylmethyldimethoxysilane, 4-glycidyloxybutyltriethoxysilane, 4-glycidyloxybutylmethyldiethoxysilane, 5-glycidyloxypentyltrimethoxysilane, 5-glycidyloxypentylmethyldimethoxysilane, 5-glycidyloxypentyltriethoxysilane, 5-glycidyloxypentylmethyldiethoxysilane, 6-Glycidyloxyhexyltrimethoxysilane, 6-Glycidyloxyhexylmethyldimethoxysilane, 6-Glycidyloxyhexyltriethoxysilane, 6-Glycidyloxyhexylmethyldiethoxysilane, 7-Glycidyloxyheptyltrimethoxysilane, 7-Glycidyloxyheptylmethyldimethoxysilane, 7-Glycidyloxyheptyltriethoxysilane, 7-Glycidyloxyheptylmethyldiethoxysilane, 8-Glycidyloxyoctyltrimethoxysilane, 8-Glycidyloxyoctylmethyldimethoxysilane Sisilane, 8-Glycidyloxyoctyltriethoxysilane, 8-Glycidyloxyoctylmethyldiethoxysilane, 9-Glycidyloxynonyltrimethoxysilane, 9-Glycidyloxynonylmethyldimethoxysilane, 9-Glycidyloxynonyltriethoxysilane, 9-Glycidyloxynonylmethyldiethoxysilane, 10-Glycidyloxydecyltrimethoxysilane, 10-Glycidyloxydecylmethyldimethoxysilane, 10-Glycidyloxydecyltriethoxysilane, 10-Glycidyloxydecylmethyldie Toxysilane, 11-Glycidyloxyundecyltrimethoxysilane, 11-Glycidyloxyundecylmethyldimethoxysilane, 11-Glycidyloxyundecyltriethoxysilane, 11-Glycidyloxyundecylmethyldiethoxysilane, 12-Glycidyloxidedecyltrimethoxysilane, 12-Glycidyloxidedecylmethyldimethoxysilane, 12-Glycidyloxidedecyltriethoxysilane, 12-Glycidyloxidedecylmethyldiethoxysilane, 13-Glycidyloxytridecyltrimethoxysilane,13-Glycidyloxytridecylmethyldimethoxysilane, 13-Glycidyloxytridecyltriethoxysilane, 13-Glycidyloxytridecylmethyldiethoxysilane, 14-Glycidyloxytetradecyltrimethoxysilane, 14-Glycidyloxytetradecylmethyldimethoxysilane, 14-Glycidyloxytetradecyltriethoxysilane, 14-Glycidyloxytetradecylmethyldiethoxysilane, 15-Glycidyloxypentadecyl Examples include dimethoxysilane, 15-glycidyloxypentadecylmethyldimethoxysilane, 15-glycidyloxypentadecyltriethoxysilane, 15-glycidyloxypentadecylmethyldiethoxysilane, 16-glycidyloxyhexadecyltrimethoxysilane, 16-glycidyloxyhexadecylmethyldimethoxysilane, 16-glycidyloxyhexadecyltriethoxysilane, and 16-glycidyloxyhexadecylmethyldiethoxysilane.

[0033] (Condensation of silane compounds) Si-OR of the above silane compounds 2 Partial hydrolysis and condensation form Si-O-Si bonds, generating a silane compound condensate (polyorganosiloxane compound). From the viewpoint of suppressing ring-opening of the epoxy group, it is preferable to carry out the reaction under neutral or basic conditions.

[0034] From the viewpoint of increasing the hardness of the cured product, the weight-average molecular weight of the polyorganosiloxane compound is preferably 500 or higher. From the viewpoint of suppressing volatilization, the weight-average molecular weight of the polyorganosiloxane compound is also preferably 500 or higher. On the other hand, if the molecular weight is excessively high, turbidity may occur due to a decrease in compatibility with other components in the composition. For this reason, the weight-average molecular weight of the polyorganosiloxane compound is preferably 20,000 or lower.

[0035] The molecular weight of polyorganosiloxane compounds can be controlled by appropriately selecting the amount of water used in the reaction, as well as the type and amount of catalyst. For example, increasing the amount of water initially added can increase the molecular weight.

[0036] Polyorganosiloxane compounds produced by hydrolysis and condensation of silane compounds are silane compounds having a T unit structure with x=3 in general formula (1) and three alkoxy groups (Si-OR 2 ) all undergo a condensation reaction to form a structure ("SiO 3 / 2 (referred to as the "T3 form") and a structure in which two of the three alkoxy groups undergo a condensation reaction to form a Si-O-Si bond ("SiO 2 / 2 This may include a "body" or "T2 body".

[0037] Polyorganosiloxane compounds are SiO 3 / 2 Body and SiO 2 / 2 Body molar ratio: [SiO 3 / 2 Body / SiO 2 / 2 [SiO] may be preferable to be less than 5. 3 / 2 Body / SiO 2 / 2 The [Isoform] may be 4 or less, 3 or less, or 2 or less, or even 0. By carrying out the reaction in the presence of a neutral salt catalyst, [SiO2] is formed. 3 / 2 Body / SiO 2 / 2 The body tends to become smaller. Examples of neutral salt catalysts include salts composed of an acid and a base, with salts composed of an alkali metal or alkaline earth metal cation and a halogen anion being preferred. Specific examples of neutral salt catalysts include lithium chloride, sodium chloride, potassium chloride, beryllium chloride, magnesium chloride, calcium chloride, lithium bromide, sodium bromide, potassium bromide, beryllium bromide, magnesium bromide, calcium bromide, lithium iodide, sodium iodide, potassium iodide, beryllium iodide, magnesium iodide, calcium iodide, etc.

[0038] When obtaining a polyorganosiloxane compound by condensation of silane compounds, multiple types of silane compounds may be condensed. For example, a silane compound in which Y in general formula (1) is an alicyclic epoxy group may be condensed with a silane compound in which Y in general formula (1) is a glycidyloxy group. In addition to the silane compound having an epoxy group represented by general formula (1), a silane compound that does not contain an epoxy group may also be used. From the viewpoint of improving the mechanical strength of the cured film, it is preferable that the number of epoxy groups contained in one molecule of the polyorganosiloxane compound be as large as possible. Therefore, when condensing silane compounds, the molar ratio of the silane compound without an epoxy group to the silane compound having an epoxy group is preferably 2 or less, more preferably 1 or less, even more preferably 0.4 or less, particularly preferably 0.2 or less, and may even be 0.

[0039] <Components other than polyorganosiloxane compounds> The curable composition contains the above-mentioned polyorganosiloxane compound as a curable resin component. In addition to the polyorganosiloxane compound as the curable resin, the curable composition preferably contains a photopolymerization initiator, and may further contain reactive diluents, photosensitizers, particles, and other additives as solid components (non-volatile components). From the viewpoint of forming a film with excellent mechanical strength, the content of the polyorganosiloxane compound in the curable composition is preferably 40 parts by weight or more, more preferably 50 parts by weight or more, and even more preferably 60 parts by weight or more, based on 100 parts by weight of the total solid components.

[0040] (Photocationic polymerization initiator) The curable composition preferably contains a photocationic polymerization initiator. The photocationic polymerization initiator is a compound (photoacid generator) that generates acid upon irradiation with active energy rays. The acid generated from the photoacid generator reacts with the epoxy groups of the polyorganosiloxane compound, causing curing by intermolecular crosslinking.

[0041] Examples of photoacid generators include strong acids such as toluenesulfonic acid or boron tetrafluoride; onium salts such as sulfonium salts, ammonium salts, phosphonium salts, iodonium salts, and selenium salts; iron-allene complexes; silanol-metal chelate complexes; sulfonic acid derivatives such as disulfones, disulfonyldiazomethanes, disulfonylmethanes, sulfonylbenzoylmethanes, imidosulfonates, and benzoin sulfonates; and organic halogen compounds.

[0042] The content of the photocationic polymerization initiator in the curable composition is preferably 100 parts by weight or less, and more preferably 50 parts by weight or less, per 100 parts by weight of the polyorganosiloxane compound.

[0043] (Reactive diluent) The curable composition may contain a reactive diluent. Examples of reactive diluents include cationic polymerizable compounds other than the polyorganosiloxane compounds mentioned above. Examples of polymerizable functional groups of the reactive diluent include epoxy groups, vinyl ether groups, oxetane groups, and alkoxysilyl groups.

[0044] The content of the reactive diluent in the curable composition is preferably 100 parts by weight or less, and more preferably 50 parts by weight or less, per 100 parts by weight of the polyorganosiloxane compound.

[0045] (Photosensitizer) The curable composition may contain a photosensitizer for purposes such as improving the photosensitivity of the photocationic polymerization initiator (photoacid generator). A photosensitizer that can absorb light in wavelength ranges that the photoacid generator itself cannot absorb is more efficient, and therefore, one that has little overlap with the absorption wavelength range of the photoacid generator is preferred. Examples of photosensitizers include anthracene derivatives, benzophenone derivatives, thioxanthone derivatives, anthraquinone derivatives, and benzoin derivatives.

[0046] The amount of photosensitizer in the curable composition is preferably 50 parts by weight or less, more preferably 30 parts by weight or less, and even more preferably 10 parts by weight or less, per 100 parts by weight of the above-mentioned photoacid generator.

[0047] (particle) The curable composition may contain particles for purposes such as adjusting film properties like surface hardness and flexibility, or suppressing curing shrinkage. Organic particles, inorganic particles, organic-inorganic composite particles, etc., may be appropriately selected and used. The particles may be surface-modified, and polymerizable functional groups may be introduced through surface modification. The average particle size is, for example, about 5 nm to 10 μm.

[0048] The particle content in the curable composition is preferably 100 parts by weight or less, and more preferably 50 parts by weight or less, per 100 parts by weight of the polyorganosiloxane compound.

[0049] (solvent) The curable composition may be solvent-free or may contain a solvent. If a solvent is included, it is preferable that the solvent does not dissolve the polyimide film. The solvent content in the curable composition is preferably 500 parts by weight or less, more preferably 300 parts by weight or less, and even more preferably 100 parts by weight or less, per 100 parts by weight of the polyorganosiloxane compound.

[0050] (Other ingredients) The curable composition may contain additives such as inorganic pigments, organic pigments, surface modifiers, surface modifiers, plasticizers, dispersants, wetting agents, thickeners, and defoamers. The curable composition may also contain thermoplastic, thermosetting, or photocurable resin materials other than the polyorganosiloxane compounds mentioned above. If the polyorganosiloxane compound and / or the resin material other than the polyorganosiloxane compound has radical polymerization properties, the curable composition may contain a radical polymerization initiator in addition to the photocationic polymerization initiator.

[0051] [Formation of a hardened film] A curable composition is applied to one main surface 1A of the substrate 1, and after drying and removing the solvent as necessary, the curable composition is cured by irradiation with active energy rays. As shown in Figure 1, a laminate 10 is obtained in which a cured film (cured material layer) 3 of the curable composition is closely laminated on the substrate 1. As shown in Figure 2, by peeling the cured material layer 3 from the substrate 1, the cured material layer 3, which is not laminated with other films, is obtained as a single-layer film.

[0052] As the base material 1, organic materials such as resins, inorganic materials such as ceramics represented by glass and metals can be used, and among these, resin films are preferred. The material of the resin film is not particularly limited, and examples include polyester resins, polyolefin resins, polyamide resins, polyimide resins, urethane resins, (meth)acrylic resins, polycarbonate resins, cellulose resins, and silicone resins. Among these, polyester resins are preferred, and polyethylene terephthalate (PET) is particularly preferred. The thickness of the base material 1 is not particularly limited, for example, 1 to 1000 μm, preferably 5 to 500 μm, more preferably 10 to 200 μm, and even more preferably 15 to 150 μm.

[0053] The substrate 1 is preferably one in which the water contact angle of the surface 1A to which the curable composition is applied is 74 to 107°. The water contact angle of surface 1A is more preferably 80 to 100°, and even more preferably 80 to 90°. If the water contact angle of the substrate 1 is excessively low, it tends to be difficult to peel the cured layer 3 from the substrate 1. If the water contact angle of the substrate 1 is excessively high, when the curable composition is applied to the substrate, it tends to repel greatly, making it difficult to form a coating film, or the coating film or cured film tends to peel off naturally from the substrate during heating or curing, making handling difficult.

[0054] The surface 1A of the substrate 1 to which the curable composition is applied may be coated in order to set the contact angle within the above range. Examples of coating treatments include release treatments using silicone-based release agents, non-silicone release agents, inorganic thin films, etc. Surface treatments such as corona treatment or plasma treatment may be performed to control the water contact angle. The surface 1B of the substrate 1 may also be surface treated.

[0055] When a curable composition is applied to a substrate 1 and irradiated with active energy rays, an acid is generated from the photocationic polymerization initiator, and the epoxy groups of the polyorganosiloxane compound undergo ring-opening and cationic polymerization, causing curing to proceed. If the additives in the curable composition, such as reactive diluents or particles, contain epoxy groups, in addition to the polymerization reaction between the polyorganosiloxane compounds, a polymerization reaction between the siloxane compound and the additive also occurs.

[0056] Ultraviolet light is preferred as the active energy ray. The cumulative irradiation dose of the active energy ray is, for example, 50 to 10,000 mJ / cm². 2 The curing temperature is approximate and can be set according to the type and amount of photocationic polymerization initiator, the thickness of the film, etc. The emission dose of active energy rays is not particularly limited, but from the viewpoint of the mechanical strength of the resulting film, it is preferably 40 W / cm or more, preferably 80 W / cm or more, and may be 120 W / cm or more. The curing temperature is not particularly limited, but is usually 90°C or lower. The curing temperature is preferably 30°C or higher, and may be 70°C or higher or 80°C or higher. Increasing the curing temperature may accelerate the curing reaction and improve the mechanical strength of film 3.

[0057] The thickness of film 3 is preferably 10 μm or more, more preferably 40 μm or more, even more preferably 45 μm or more, and may be 50 μm or more or 90 μm or more. When the thickness of film 3 is 40 μm or more, mechanical properties such as surface hardness tend to be improved. Furthermore, even when the thickness of film 3 is 40 μm or more, it exhibits excellent fold recovery. The thickness of film 3 is preferably 500 μm or less, more preferably 150 μm or less, and even more preferably 120 μm or less. When the thickness of film 3 is greater than 500 μm, transparency and fold recovery may be inferior.

[0058] The single-layer film 3, consisting of a cured material layer, is not laminated with other films, so interfacial delamination does not occur, resulting in excellent handling properties. Furthermore, the single-layer film 3 is less prone to retaining bend marks and exhibits excellent bending recovery properties.

[0059] The bending recovery property is evaluated by the following method. A rectangular sample measuring 30 mm x 70 mm is bent 180° with a radius of 3 mm, using the center of the long side as the bending axis, and held in an environment of 60°C and 90% relative humidity for 24 hours. After that, with the bending load removed, the sample is placed on a horizontal stand in an environment of 23°C and 55% relative humidity, and after 20 minutes, the bending angle (several-angle) of the sample at the bending axis is measured. If the sample is not bent at the bending axis and is flat, the bending angle (bending recovery angle) is 180°. The larger this bending recovery angle, the higher the bending recovery property, which has the advantage of making it less likely for creases to remain in the bent part of a foldable display. The bending recovery angle of film 3 is preferably 90° or more, more preferably 120° or more, even more preferably 150° or more, and ideally 180°.

[0060] The single-layer film 3, consisting of a cured polyorganosiloxane compound layer, also exhibits excellent bending resistance. In a cylindrical mandrel test in accordance with JIS-K5600, the mandrel radius at which cracks occur is preferably 6 mm or less, more preferably 3 mm or less, and may also be 2 mm or less or 1 mm or less. When repeated bending tests are performed at a radius of 3 mm using a U-bending tester, the number of bending cycles before cracks or fractures occur is preferably 100,000 or more.

[0061] Film 3 is preferably rated 6B or higher in a pencil hardness test in accordance with JIS-K5600. The pencil hardness may be 4B or higher, or 2B or higher, or 3H or higher, or 4H or higher.

[0062] The total light transmittance of film 3 is preferably 85% or higher, more preferably 88% or higher, even more preferably 90% or higher, and may be 91% or higher, or 92% or higher. The haze of film 3 is preferably 1.5% or lower, more preferably 0.9% or lower, even more preferably 0.6% or lower, and may be 0.2% or lower. The yellowness (YI) of film 3 is preferably 3.0 or lower, preferably 2.0 or lower, preferably 1.0 or lower, and particularly preferably 0.7 or lower.

[0063] [Laminated film] Film 3 may be bonded to other films or the like via an adhesive layer to form a laminate. Figure 3 is a cross-sectional view of a laminated film in which film 3 and transparent resin film 5 are bonded together via an adhesive layer 7.

[0064] Examples of resin materials for transparent resin films include polyester resins such as polyethylene terephthalate and polyethylene naphthalate (PEN), polyolefin resins such as polyethylene, polypropylene, and cyclic polyolefins, polyamide resins, polyimide resins, urethane resins, (meth)acrylic resins, polycarbonate resins, cellulose resins such as triacetylcellulose, and silicone resins. Among these, polyester resins are preferred, and polyethylene terephthalate is particularly preferred. The transparent resin film 5 may contain two or more resin materials.

[0065] The thickness of the transparent resin film 5 is not particularly limited, but is preferably 5 to 100 μm, and may be 10 to 75 μm or 20 to 50 μm. If the thickness is too small, the mechanical properties may be insufficient, and if the thickness is too large, the flexibility and transparency of the laminated film may be insufficient. When the laminated film 20 is used as a cover window material for a foldable display, the thickness of the transparent resin film 5 is preferably 50 μm or less, and may be 40 μm or less, 30 μm or less, or 25 μm or less. Even if the thickness of the transparent resin film 5 is small, the film 3 consisting of the cured layer bonded to its surface has high mechanical strength, so a laminated film 20 with excellent surface hardness can be obtained.

[0066] A pressure-sensitive adhesive is preferred as the adhesive for the adhesive layer 7. Since the pressure-sensitive adhesive does not require curing after bonding, stress at the bonding interface due to curing shrinkage, etc., is less likely to occur. Therefore, even when the thickness of the transparent resin film 5 is small, curling of the laminated film 20 is less likely to occur.

[0067] The adhesive layer 7 is preferably a double-sided adhesive sheet. Examples of double-sided adhesive sheets include a substrate-attached transparent adhesive film having adhesive layers on both sides of a transparent resin film, and a substrate-less double-sided adhesive sheet consisting only of an adhesive layer. From the viewpoint of transparency and thinness, a substrate-less double-sided adhesive sheet is preferred. As a substrate-less double-sided adhesive sheet, optical transparent adhesive tape called OCA (Optical Clear Adhesive) is preferred. Examples of polymer materials for the adhesive include (meth)acrylic resins, urethane resins, silicone resins, epoxy resins, crosslinked rubber, thermoplastic elastomers, etc. Among these, (meth)acrylic resins are preferred.

[0068] The thickness of the double-sided adhesive sheet 7 is preferably 5 μm or more, more preferably 10 μm or more, and may be 20 μm or more. A larger thickness of the double-sided adhesive sheet enhances the adhesion between the film 3 and the transparent resin film 5, and the stress generated at the bonding interface can be relieved by the double-sided adhesive sheet. As a result, curling of the laminated film 20 is suppressed, and peeling at the folded portion when the laminated film 20 is folded tends to be suppressed. From the viewpoint of transparency and thinness, the thickness of the double-sided adhesive sheet 7 is preferably 500 μm or less, more preferably 100 μm or less, and may be 50 μm or less.

[0069] A laminated film 20 is obtained in which the film 3 and the transparent resin film 5 are laminated via the double-sided adhesive sheet 7 by laminating the film 3 to one side of the double-sided adhesive sheet 7 and laminating the transparent resin film 5 to the other side of the double-sided adhesive sheet 7. The order of lamination is not particularly limited; the transparent resin film 5 may be laminated after the film 3 and the double-sided adhesive sheet 7 are laminated, or the film 3 may be laminated after the transparent resin film 5 and the double-sided adhesive sheet 7 are laminated. Alternatively, the transparent resin film 5 may be laminated via the double-sided adhesive sheet 7 to the side of the cured material layer 3 of the laminate 10 in which the cured material layer 3 is tightly laminated on the substrate 1, and then the substrate 1 may be peeled off from the cured material layer 3.

[0070] The configuration, in which a film 3 consisting of a cured material layer and a transparent resin film 5 are bonded together via an adhesive layer 7, allows for the creation of a cured material layer on the surface of any transparent resin film, thereby improving its surface hardness. Therefore, even in applications where a transparent resin film alone would be difficult to apply due to insufficient properties such as scratch resistance, the laminated film 20 may become applicable.

[0071] Furthermore, even if the thickness of the transparent resin film 5 is small and the surface hardness is insufficient, the surface hardness can be improved by laminating it with the film 3, which consists of a cured material layer. Because the thickness of the transparent resin film 5 can be reduced, bending marks are less likely to remain in the bent parts, and it has excellent resilience. In particular, when the film 3, which consists of a cured material layer, and the transparent resin film 5 are laminated together via a double-sided adhesive sheet, the adhesive has a stress-relieving effect, so peeling at the interface is less likely to occur compared to a hard coat film in which a hard coat layer is formed directly on the transparent resin film, and bending resistance and bending recovery tend to be improved.

[0072] A laminated film 20, formed by bonding a film 3 consisting of a cured polyorganosiloxane compound layer to a transparent resin film 5, exhibits excellent flexibility. When the laminate 20 is subjected to a cylindrical mandrel test in accordance with JIS-K5600 with the film 3 facing outward, the mandrel radius at which cracks occur in the film 3 is preferably 6 mm or less, more preferably 3 mm or less, and may also be 2 mm or less or 1 mm or less. When the laminate 20 is subjected to a cylindrical mandrel test in accordance with JIS-K5600 with the film 3 facing inward, the mandrel radius at which cracks occur in the film 3 is preferably 3 mm or less, more preferably 2 mm or less, and may also be 1 mm or less.

[0073] The pencil hardness of the film 3 side of the laminated film 20 is preferably 6B or higher, and may be 3B or higher or B or higher. The total light transmittance of the laminated film 20 is preferably 85% or higher, more preferably 88% or higher, and even more preferably 90% or higher. The haze of the laminated film 20 is preferably 1.5% or less, and more preferably 1.0% or less.

[0074] [Applications of single-layer and laminated films] The above-mentioned film 3 and laminated film 20 may have various functional layers on both sides or one side. Examples of functional layers include anti-reflective layers, anti-glare layers, anti-static layers, and transparent electrodes. A transparent adhesive layer may also be attached for bonding with other components.

[0075] Single-layer films and transparent resin film laminates can be used, for example, as cover window materials placed on the viewing surface of an image display panel. Due to their excellent flexibility and bend recovery properties, they are also suitable for use as cover windows for foldable displays. [Examples]

[0076] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0077] [Synthesis of polyorganosiloxane compounds] <Synthesis Example 1> In a reaction vessel equipped with a thermometer, stirrer, and reflux condenser, 66.5 g (270 mmol) of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (Momentive Performance Materials "SILQUEST A-186") and 16.5 g of 1-methoxy-2-propanol (PGME) were charged and mixed uniformly. To this mixture, 0.039 g (0.405 mmol) of magnesium chloride, used as a catalyst, was dissolved in a mixture of 9.7 g (539 mmol) of water and 5.8 g of methanol, and this solution was added dropwise over 5 minutes, while mixing until homogeneous. The temperature was then raised to 80°C, and the polycondensation reaction was carried out for 6 hours with stirring. After the reaction was complete, the solvent and water were removed by distillation using a rotary evaporator to obtain polyorganosiloxane compound 1.

[0078] Tosoh's GPC system "HLC-8220GPC" (Column: TSKgel GMH) XL ×2 bottles, TSKgel G3000H XL TSKgel G2000H XL The weight-average molecular weight (Mw) in polystyrene terms, as measured by Agilent 600MHz-NMR, was 3000. 29 [SiO2] calculated from SiNMR measurements 3 / 2 Body / SiO 2 / 2 The ratio of [units] was 2.3. This was measured using a Bruker 400 MHz NMR spectrum with deuterated acetone as the solvent. 1 The residual rate of epoxy groups, calculated from the 1H-NMR spectrum, was over 95%.

[0079] <Synthesis Example 2> In a reaction vessel equipped with a thermometer, stirrer, and reflux condenser, 67.4 g (220 mmol) of 8-glycidyloxyoctyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd.; KBM-4803) and 11.6 g of methanol were charged and mixed uniformly. To this mixture, a solution of 0.010 g (0.11 mmol) of magnesium chloride as a catalyst, dissolved in a mixture of 11.9 g (660 mmol) of water and 4.7 g of methanol, was added dropwise over 5 minutes and mixed until uniform. The mixture was then heated to 70°C and the polycondensation reaction was carried out for 6 hours with stirring. After the reaction was complete, the solvent and water were removed by distillation using a rotary evaporator to obtain polyorganosiloxane compound 2. The weight-average molecular weight Mw of polyorganosiloxane compound 2 is 4500, and [SiO2] 3 / 2 Body / SiO 2 / 2 The ratio of the [body] to the [residue] was 2.1, and the remaining epoxy group rate was 95% or more.

[0080] [Preparation of curable compositions] Curable compositions A and B, as shown in Table 1, were prepared by adding a photocationic polymerization initiator and a leveling agent to a curable resin component. The values ​​in Table 1 are in parts by weight, and the amounts of the photocationic polymerization initiator and leveling agent are the weight of the solids of each component relative to 100 parts by weight of the total resin component.

[0081] In Table 1, each component is listed using the following abbreviations. <Photopolymerization initiator> CPI-101A: 50% propylene carbonate solution of phenyl(4-phenylthiophenyl)sulfonium·SbF6 (manufactured by Sunapro, "CPI-101A") CPI-200K: Triarylsulfonium-P(Rf) n F 6-n 50% propylene carbonate solution of salt (SunApro "CPI-200K") <Leveling agent> BYK-300: 52% xylene / isobutanol solution of polyether-modified polydimethylsiloxane (BYK "BYK-300")

[0082] [Table 1]

[0083] [Film production] <Example 1> A 50 μm thick PET film (Fujimori Kogyo Co., Ltd. "38E-0010NSP-5", water contact angle of the release-treated surface measured using a contact angle meter (Kyowa Jounken Kagaku Co., Ltd. "PCA-11": 83°) with one side treated for release was coated with curable composition A using a bar coater and heated at 120°C for 10 minutes. Then, while adjusting the surface temperature of the coating to 30°C, the composition was cured by irradiating it with ultraviolet light from a distance of 200 mm using a high-pressure mercury lamp with an emission dose of 80 W / cm. After that, the cured layer was peeled off from the release film to obtain a single-layer film with a thickness of 48 μm.

[0084] <Example 2> A release film (Fujimori Kogyo Co., Ltd. "75E-0010NSK") with a thickness of 75 μm and a water contact angle of 84° on the release surface was used. The surface temperature of the coating film during UV irradiation, the emission dose of the high-pressure mercury lamp, and the thickness of the cured layer were changed as shown in Table 2. Otherwise, a single-layer film was obtained in the same manner as in Example 1.

[0085] <Example 3> A release film (Fujimori Kogyo Co., Ltd. "50E-0010NSD") with a thickness of 50 μm and a water contact angle of 107° on the release surface was used. Otherwise, a single-layer film was obtained in the same manner as in Example 2.

[0086] <Example 4> The surface temperature of the coating film during ultraviolet irradiation, the emission dose of the high-pressure mercury lamp, and the thickness of the cured layer were changed as shown in Table 2. Otherwise, a single-layer film was obtained in the same manner as in Example 1.

[0087] <Examples 5-7> Using curable composition B, the coating and photocuring were performed on a release film under the conditions shown in Table 2. After that, the cured layer was peeled off the release film to obtain a single-layer film.

[0088] <Comparative Examples 1, 2> In Comparative Example 1, a 50 μm thick PET film (Toray's "Lumirror U48", water contact angle: 73°) with both sides treated for easy adhesion was used as a substrate, and curable composition A was applied. An attempt was made to produce a single-layer film consisting of a cured layer under the same conditions as in Example 2, but the cured layer could not be peeled off the PET film. In Comparative Example 2, a curable composition layer B was used instead of curable composition A to produce a single-layer film consisting of a cured layer, but similar to Comparative Example 1, the cured layer could not be peeled off the PET film.

[0089] <Comparative Examples 3, 4> In Comparative Example 3, a 75 μm thick PET film with one side treated for release (release film attached to 3M's transparent double-sided adhesive tape "8146-1", water contact angle of the release-treated surface: 108°) was used as the substrate, and curable composition A was applied to the release-treated surface, but significant repulsion occurred, and a film could not be formed. In Comparative Example 4, where curable composition layer B was used instead of curable composition A, a film could not be formed, similar to Comparative Example 3.

[0090] [evaluation] <Coating properties> When the curable composition was applied, heated, and cured, those that did not exhibit repulsion were designated as A, and those that exhibited weak repulsion were designated as B. The presence or absence of repulsion was determined based on whether or not there was a significant reduction in the coated area compared to the situation immediately after application. As described above, in Comparative Examples 3 and 4, the coating film was discontinuous due to significant repulsion, and a film could not be formed. <Pencil hardness> The pencil hardness of the film was measured under a load of 750g, in accordance with JIS K5600.

[0091] <Mandrel radius> In accordance with JIS K5600-5-1:1999, a cylindrical mandrel test was performed using a Type 1 testing machine to determine the bending radius at which cracks occur in the film.

[0092] <Folding and recovery angle> A sample was prepared by cutting the film into a rectangle with a short side of 30 mm and a long side of 70 mm. The sample was folded 180° with a radius of 3 mm at the center of the long side, and held in an environment of 60°C and 90% relative humidity for 24 hours. After that, with the bending load removed, the sample was placed on a horizontal surface in an environment of 23°C and 55% relative humidity, and the bending angle (several angles) of the sample at the bending axis was measured after 20 minutes.

[0093] <Repeated bending test> Samples were prepared by cutting the films of Examples 2, 5, and 6 into rectangles with a short side of 25 mm and a long side of 110 mm. A planar unloaded U-shaped stretch test fixture (manufactured by Yuasa System Equipment Co., Ltd.) was attached to the short side of the test piece, and the test was performed on a benchtop durability tester ("DMLHB" manufactured by Yuasa System Equipment Co., Ltd.) at a temperature of 23°C and a relative humidity of 55%, with 100,000 repeated bending tests at a bending radius of 3 mm and a speed of 1 time / second. None of the films showed cracks after 100,000 bending tests, demonstrating good bending resistance.

[0094] <Total light transmittance and haze> The haze meter "HZ-V3" manufactured by Suga Test Instruments was used, and measurements were taken according to the methods described in JIS K7361-1:1999 and JIS K7136:2000. A D65 light source was used for the measurements, and the total light transmittance was calculated as the ratio of the total transmitted light flux (parallel light component and diffuse light component) to the parallel incident light flux to the hard coat film.

[0095] <Yellowness> Measurements were taken using a Suga Test Instruments SC-P colorimeter in transmission mode. A D65 light source was used for the measurements.

[0096] Table 1 shows the manufacturing conditions (water contact angle of the substrate, type of composition, curing conditions), application performance evaluation results, film thickness, and film evaluation results for Examples 1 to 7. Table 1 also includes, as reference examples, evaluation results for pencil hardness, bending recovery angle, total light transmittance, haze, and yellowness for a 50 μm thick polyethylene terephthalate (PET) film (Toray Industries, Ltd. "Lumirror U48"), a 50 μm thick polyethylene naphthalate (PEN) film (Toyobo Industries Ltd. "Teonex Q65-HA"), and a 40 μm thick triacetylcellulose (TAC) film.

[0097] [Table 2]

[0098] While PET and PEN films with a thickness of 50 μm had a bending recovery angle of 70° or less, the films of Examples 1, 2, 5, and 6, which consist of a cured polyorganosiloxane compound layer, had a bending recovery angle of 120° or more, indicating that they were less prone to leaving creases. Furthermore, the films of Examples 1 and 2, which consist of a cured layer of composition A with a polyorganosiloxane compound having alicyclic epoxy groups as the curable resin component, not only exhibited excellent bending recovery but also had higher pencil hardness and superior surface hardness compared to PET, PEN, and TAC films. The film of Example 4, with a thickness of 120 μm, had an even higher pencil hardness.

[0099] The films of Examples 1-3 and 5-7 showed excellent flexural resistance, with no cracks even at a mandrel radius of 1 mm. The film of Example 4, with a thickness of 120 μm, had a mandrel radius of 6 mm, demonstrating good flexural resistance even at greater thicknesses. Furthermore, as mentioned above, the films of Examples 2, 5, and 6 possessed flexural resistance capable of withstanding 100,000 repeated bends.

[0100] The films of Examples 1 to 7 all exhibited high total light transmittance, low haze and YI, and transparency comparable to optical films such as PET film, PEN film, and TAC film. Even the thicker films of Examples 4 and 7 showed excellent transparency.

[0101] [Fabrication and evaluation of laminated films] A 20 μm thick PET film was laminated to one side of a 25 μm thick transparent double-sided adhesive tape (3M "8146-1"), and then the films from Examples 2, 4, 6, and 7 were laminated to the other side to create a laminated film with a total thickness of approximately 100 μm.

[0102] For the laminated films, cylindrical mandrel tests were performed on the example films, either with the film bent inward (internal bending) or outward (external bending), to determine the bending radius at which cracks occurred in the example films. The results are shown in Table 3.

[0103] [Table 3]

[0104] All laminated films exhibited good bending resistance in both inward and outward bending conditions. [Explanation of Symbols]

[0105] 1 Base material 3. Cured layer (single-layer film) 5 Transparent resin film 7. Adhesive layer (double-sided adhesive sheet) 10 Laminate 20 Laminated Film

Claims

1. A cured layer of a composition comprising 40 parts by weight or more of a polyorganosiloxane compound, which is a condensate of one or more silane compounds including at least one silane compound represented by the following general formula (1), per 100 parts by weight of the total nonvolatile content, A single-layer film in which, among the one or more silane compounds, the molar ratio of the silane compound without an epoxy group to the silane compound having an epoxy group represented by the following general formula (1) is 0.2 or less: Y-R １ -(Si(OR ２ ) ｘ R ３ ３－ｘ ) …(1) In general formula (1), R １ R is a substituted or unsubstituted alkylene group having 1 to 16 carbon atoms; ２ R is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; ３ x is a hydrogen atom, or a monovalent hydrocarbon group selected from C1-C10 alkyl groups, C6-C25 aryl groups, and C7-C12 aralkyl groups; x is an integer of 2 or 3; and Y is a glycidyloxy group or an alicyclic epoxy group.

2. The film according to claim 1, having a thickness of 40 to 120 μm.

3. In the above general formula (1), R １ is a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms, and Y is an alicyclic epoxy group. The film according to claim 1 or 2.

4. In the above general formula (1), R １ The film according to claim 1 or 2, wherein is a substituted or unsubstituted alkylene group having 4 to 16 carbon atoms, and Y is a glycidyloxy group.

5. A method for manufacturing a film according to any one of claims 1 to 4, A step of applying a composition containing 40 parts by weight or more of the polyorganosiloxane compound per 100 parts by weight of the total non-volatile content onto a substrate; A step of irradiating the composition with active energy rays to cure the composition on the substrate and form a cured layer; and A step of peeling the cured layer from the substrate, A method for manufacturing a film, comprising the following in order.

6. The method for manufacturing a film according to claim 5, wherein the substrate has a water contact angle of 74 to 107° on the surface to which the composition is applied.

7. A laminated film in which a film according to any one of claims 1 to 4 and a transparent resin film are bonded together via an adhesive layer.

8. The laminated film according to claim 7, wherein the adhesive layer is a double-sided adhesive sheet.

9. The laminated film according to claim 8, wherein the thickness of the double-sided adhesive sheet is 10 μm or more.

10. The laminated film according to any one of claims 7 to 9, wherein the thickness of the transparent resin film is 50 μm or less.

11. A display in which the film according to any one of claims 1 to 4 is disposed on the viewing surface of the image display panel.

12. A display in which the laminated film according to any one of claims 7 to 10 is disposed on the viewing surface of the image display panel.

13. The display according to claim 11 or 12, which is foldable.

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