Hard coat composition, laminated film, and cured film

Abstract

The present application provides a hard coat composition which, after curing, can produce a hard coat layer having excellent scratch resistance and high hardness, and also excellent moldability during processing, a laminate film having such a hard coat composition, and the like. The above problem is solved by a hard coat composition which is a curable hard coat composition, contains a (meth)acryl polymer and inorganic oxide nanoparticles, the (meth)acryl polymer has a double bond equivalent weight of 100 to 1000 g / eq, and has a weight average molecular weight of 5,000 to 200,000. The inorganic oxide nanoparticles are in a non-aggregated state, have an average particle diameter of 7 nm or more and less than 50 nm, and have a copolymerizable group on the surface. The hard coat composition contains 50 to 70% by weight of the (meth)acryl polymer and 50 to 30% by weight of the inorganic oxide nanoparticles, based on the total weight of the hard coat composition, and the content of components other than the (meth)acryl polymer and the inorganic oxide nanoparticles in the hard coat composition is less than 10 mass%.

Description

[0001] This case is a divisional application filed on August 5, 2019, with application number 201980051459.5 (PCT / JP2019 / 030745) and invention titled Hard Coating Composition, Laminated Film and Cured Film. Technical Field

[0002] This invention relates to hard coating compositions, and more particularly to curable hard coating compositions and laminated films containing hard coating compositions. Background Technology

[0003] Currently, resin film laminates with hard coatings are used in various fields (see Patent Document 1). For example, such resin film laminates are used in front panels and back panels of mobile devices and automotive interior components.

[0004] Existing technical documents Patent documents Patent Document 1: Japanese Patent Publication No. 2017-508828 Summary of the Invention

[0005] The problem that the invention aims to solve The hard coating on the surface of a resin film laminate is considered to require a certain level of hardness and high scratch resistance. On the other hand, in order to manufacture a resin film laminate with a desired shape, the resin films constituting each layer need excellent formability. However, it is difficult to meet all these different properties in the resin composition used to manufacture the laminate, especially the hard coating.

[0006] Therefore, the objective of this invention is to provide a hard coating composition that has excellent scratch resistance and high hardness after curing and excellent formability during processing, as well as a laminate film having such a hard coating composition.

[0007] Methods for solving problems The inventors of this invention discovered that a curable hard coating composition comprising a specified polymer and nanoparticles has excellent characteristics that can solve the above-mentioned problems, thus completing this invention.

[0008] That is, the present invention is as follows.

[0009] (1) A hard coating composition, which is a curable hard coating composition, comprising: (Meth)acryloyl polymers and inorganic oxide nanoparticles, The above-mentioned (meth)acryloyl polymers have a (meth)acrylic equivalent of 200–500 g / eq and a weight-average molecular weight of 5,000–200,000. The average particle size of the aforementioned inorganic oxide nanoparticles is greater than 6 nm and less than 95 nm.

[0010] (2) The hard coating composition as described in (1) above, wherein the (meth)acryloyl polymer comprises repeating units as shown in formula (I) below. In the above formula (I), m is an alkylene group having 1 to 4 carbon atoms or a single bond. n is an alkyl group or hydrogen with 1 to 4 carbon atoms. p is a single bond or an alkylene group with 1 or 2 carbon atoms. q is an alkyl group or hydrogen that may contain at least one of the substituents selected from epoxy, hydroxyl, acryloyl, and methacryloyl groups, and has a total carbon number of 1 to 12.

[0011] (3) The hard coating composition as described in (2) above, wherein, in the above formula (I), m is an alkylene group with 1 or 2 carbon atoms. n is an alkyl group with 1 or 2 carbon atoms.

[0012] p represents a single bond or a methylene group. q is an alkyl group or hydrogen group that may contain at least one of the substituents selected from glycidyl, hydroxyl and acryloyl groups, and has a total carbon number of 1 to 6.

[0013] (4) The hard coating composition as described in (2) above, wherein the (meth)acryloyl polymer comprises at least one of the repeating units shown in formula (II-a), formula (II-b) and formula (II-c). (5) The hard coating composition as described in any one of (1) to (4) above, wherein the hard coating composition comprises 20 to 80% by weight of the (meth)acryloyl polymer and 80 to 20% by weight of inorganic oxide nanoparticles based on the total weight of the hard coating composition.

[0014] (6) The hard coating composition as described in any one of (1) to (5) above, wherein the inorganic oxide nanoparticles are contained in silicon dioxide having copolymeric groups on the surface.

[0015] (7) The hard coating composition as described in any one of (1) to (6) above, further comprising a leveling agent.

[0016] (8) The hard coating composition as described in (7) above, wherein the leveling agent comprises a fluorine-based additive or an organosilicon-based additive.

[0017] (9) The hard coating composition as described in (7) or (8) above, wherein the hard coating composition contains 10% by weight or less of the leveling agent based on the total weight of the hard coating composition.

[0018] (10) The hard coating composition as described in any one of (1) to (9) above is an energy-curable hard coating composition.

[0019] (11) The hard coating composition as described in any one of (1) to (10) above further comprises a photopolymerization initiator.

[0020] (12) The hard coating composition as described in any one of (1) to (11) above, wherein, The aforementioned hard coating composition was applied to the PMMA resin side of a substrate layer obtained by laminating polycarbonate resin and PMMA resin, resulting in a coating layer with a thickness of 7 μm. The coating was dried at 120°C for 5 minutes and then cut into samples of 210 mm × 297 mm × 0.3 mm (thickness) to obtain a laminated sample. In this laminated sample... The aforementioned laminate was preheated at 190°C for 40 seconds. The sample was placed in a mold with a deep drawing height of 13 mm and a right-angled protrusion with length and width both 30 mm, with the polycarbonate resin side of the substrate layer in contact with the mold. The laminate sample was then pressurized using 3.5 MPa of high-pressure air. The radius R of the area in contact with the right-angled protrusion of the molded body is within 3 mm, and the coating layer on the molded body does not crack.

[0021] (13) The hard coating composition as described in any one of (1) to (12) above, wherein, The above-mentioned hard coating composition is applied to the surface of the PMMA resin side of the substrate layer obtained by laminating polycarbonate resin and PMMA resin, so that a coating layer with a thickness of 7 μm is formed by the above-mentioned hard coating composition, and then dried at 120°C for 5 minutes. A 30 μm thick polypropylene masking film is attached to the surface of the uncured coating layer, and a 30 kg / m² pressure is applied to the masking film. 2 After 24 hours of pressure, the surface roughness Sa of the coating layer after the masking film is peeled off is less than 0.01 μm.

[0022] (14) A laminated film comprising a coating layer having any one of the hard coating compositions described in (1) to (13) above on a resin-containing substrate layer.

[0023] (15) The laminated film as described in (14) above, wherein the thickness of the substrate layer is 0.1 mm to 1.0 mm and the thickness of the coating layer is 1.0 μm to 10 μm.

[0024] (16) A cured film obtained by curing the laminated film described in (14) or (15) above.

[0025] (17) The cured film as described in (16) above, wherein the pencil hardness of the surface of the coating layer side is B or above.

[0026] (18) A cured film as described in (16) or (17) above, wherein #0000 steel wool is applied to the surface of the coating layer side at 100 gf / cm². 2 Under pressure and repeated abrasion 15 times, the haze change (ΔH) of the above coating before and after abrasion, as evaluated based on JIS K 7136:2000, is less than 3.0%.

[0027] (19) The cured film as described in any one of (16) to (18) above, wherein the evaluation result of the adhesion of the coating layer side determined according to JIS K 5600-5-6:1999 is 0.

[0028] The effects of the invention The hard coating composition of the present invention, as described above, contains a specified polymer and nanoparticles, and when cured, it can form a hard coating with high hardness and scratch resistance, and has excellent formability in the uncured state.

[0029] Thus, due to its excellent characteristics, the hard coating composition of the present invention is particularly suitable, for example, as a material for resin film laminates used in mobile devices, automotive interior parts, etc. Attached Figure Description

[0030] Figure 1 A cross-sectional view showing a specific example of a laminated film including a coating layer having a hard coating composition.

[0031] Symbol Explanation 10. Laminated membranes 12 Coating layer 20. Polymethyl methacrylate layer (PMMA resin layer) 22. Polycarbonate layer (PC resin layer) Detailed Implementation

[0032] The present invention will now be described in detail. Furthermore, the present invention is not limited to the embodiments described below, and can be implemented in any way that achieves the desired inventive effect.

[0033] [Hard coating composition] The hard coating composition of the present invention has curability that is achieved by irradiation with an energy line, and comprises a (meth)acryloyl polymer and inorganic oxide nanoparticles. As will be described in detail below, the hard coating composition exhibits excellent formability and tack-free properties before curing, and furthermore, when cured to form, for example, a hard coating, it can achieve high hardness and excellent scratch resistance.

[0034] The hard coating composition preferably comprises 20-80% by weight of (meth)acryloyl polymer and 80-20% by weight of inorganic oxide nanoparticles, based on the total weight of the hard coating composition. More preferably, the hard coating composition comprises 30-70% by weight of (meth)acryloyl polymer and 70-30% by weight of inorganic oxide nanoparticles, and even more preferably, it comprises 40-60% by weight of (meth)acryloyl polymer and 60-40% by weight of inorganic oxide nanoparticles.

[0035] <(Meth)acryloyl polymer> The (meth)acryloyl polymer has a (meth)acrylic acid equivalent of 200 to 500 g / eq. The (meth)acryloyl polymer preferably has a (meth)acrylic acid equivalent of 220 to 450 g / eq, more preferably 250 to 400 g / eq.

[0036] The (meth)acryloyl polymer preferably has a double bond equivalent of 100 to 1000 g / eq, more preferably 150 to 800 g / eq, even more preferably 200 to 600 g / eq, and particularly preferably 250 to 400 g / eq.

[0037] Furthermore, the (meth)acryloyl polymer has a weight-average molecular weight of 5,000 to 200,000. The weight-average molecular weight of the (meth)acryloyl polymer is preferably 10,000 to 150,000, more preferably 15,000 to 100,000, and even more preferably 18,000 to 50,000.

[0038] The weight-average molecular weight can be determined according to paragraphs 0061 to 0064 of Japanese Patent Application Publication No. 2007-179018. The details of the determination method are as follows.

[0039] [Table 1] Determination conditions of weight-average molecular weight First, a standard curve representing the relationship between elution time and the molecular weight of polycarbonate is prepared using a general calibration method with polystyrene as the standard polymer. Then, the elution curve (chromatogram) of polycarbonate is determined under the same conditions as the standard curve described above. Next, the weight-average molecular weight (Mw) is calculated from the elution time (molecular weight) of the polycarbonate and the peak area (number of molecules) at that elution time. The weight-average molecular weight is represented by the following formula (A), where Ni refers to the number of molecules with a molecular weight Mi.

[0040] Mw=Σ(NiMi 2 ) / Σ(NiMi)・・・・(A) Furthermore, in this specification, (meth)acrylic acid includes any of acrylic acid and methacrylic acid.

[0041] As described above, the hard coating composition comprising a (meth)acrylamide polymer having a specified range of (meth)acrylic acid equivalent and weight-average molecular weight exhibits good surface dryness before curing and scratch resistance after curing, and can also be easily cured and polymerized.

[0042] The (meth)acryloyl polymer contained in the hard coating composition preferably has repeating units as shown in the following formula (I). In formula (I), m is an alkylene group or a single bond with 1 to 4 carbon atoms, n is an alkyl group or hydrogen with 1 to 4 carbon atoms, p is a single bond or an alkylene group with 1 or 2 carbon atoms, and q is an alkyl group or hydrogen with a total number of 1 to 12 carbon atoms that may contain at least one of the substituents selected from epoxy, hydroxyl, acryloyl and methacryloyl groups.

[0043] The (meth)acryloyl polymer more preferably contains the following repeating unit, namely, in the above formula (I), m is an alkylene group with 1 or 2 carbon atoms, n is an alkyl group with 1 or 2 carbon atoms, p is a single bond or methylene group, and q is an alkyl or hydrogen repeating unit with a total number of 1 to 6 carbon atoms that may contain at least one substituent of glycidyl group, hydroxyl group and acryloyl group.

[0044] For example, in the above formula (I), m is methylene, n is methyl, p is a single bond, q is methyl, alkyl with 5 or fewer carbon atoms containing glycidyl (epoxy) group, alkyl with 8 or fewer carbon atoms containing hydroxyl and acryloyl group, etc.

[0045] Specific examples of repeating units contained in (meth)acryloyl polymers include the repeating units shown in formulas (II-a), (II-b), and (II-c) below. In the (meth)acryloyl polymer, the repeating unit of formula (II-a) is preferably 30 to 85 mol%, more preferably 40 to 80 mol%, based on the total molar number of the repeating units of formula (II-a), formula (II-b), and formula (II-c). The repeating unit of formula (II-b) is preferably 5 to 30 mol%, more preferably 10 to 25 mol%, based on the total molar number mentioned above. Furthermore, the repeating unit of formula (II-c) is preferably 10 to 40 mol%, more preferably 10 to 35 mol%, based on the total molar number mentioned above.

[0046] Furthermore, the molar ratio of the repeating unit in formula (II-a), the repeating unit in formula (II-b), and the repeating unit in formula (II-c) is preferably 4.5 to 5.5: 1.5 to 2.5: 2.5 to 3.5, for example, 5: 2: 3.

[0047] A pentaerythritol-based multifunctional acrylate compound can be added to the (meth)acryloyl polymer. As a multifunctional acrylate compound having multiple acrylate groups, preferably having three or more acrylate groups, for example, pentaerythritol tetraacrylate and dipentaerythritol hexaacrylate as shown in formulas (III-a) and (III-b) respectively can be used, as well as pentaerythritol triacrylate, etc. The multifunctional acrylate compound is preferably contained in 70% by weight or less, more preferably in 50% by weight or less, based on the total weight of the (meth)acryloyl polymer. Thus, by adding the multifunctional acrylate compound to the hard coating composition, it reacts with the acryloyl groups, glycidyl groups (epoxy groups), and hydroxyl groups contained in the side chains of the (meth)acryloyl polymer, thereby forming a hard coating film with higher scratch resistance.

[0048] <Inorganic Oxide Nanoparticles> Inorganic oxide nanoparticles contained in the hard coating composition can include silica particles and alumina particles, among which silica particles are preferably included, and the silica particles are preferably at least colloidal silica.

[0049] The inorganic oxide nanoparticles contained in the hard coating are preferably treated with a surface treatment agent. Surface treatment enables the inorganic oxide nanoparticles to be dispersed in a stable state in the hard coating composition, especially in the (meth)acryloyl polymer component.

[0050] As surface treatment agents for inorganic oxide nanoparticles, compounds having substituents that can bond to the surface of inorganic oxide nanoparticles and substituents that are highly compatible with components of the hard coating composition that disperses inorganic oxide nanoparticles, particularly (meth)acryloyl polymers, are suitable. For example, silane compounds, alcohols, amines, carboxylic acids, sulfonic acids, phosphonic acids, etc., can be used as surface treatment agents.

[0051] Inorganic oxide nanoparticles preferably have copolymeric groups on their surface. These copolymeric groups can be introduced through surface treatment of the inorganic oxide nanoparticles. Specific examples of copolymeric groups include vinyl groups, (meth)acrylic groups, and free radical polymerizable groups.

[0052] The average particle size of the inorganic oxide nanoparticles is greater than 6 nm and less than 95 nm. More preferably, the average particle size of the inorganic oxide nanoparticles is 7–50 nm, and even more preferably 8–20 nm.

[0053] To ensure that the cured surface of the hard coating composition is free of unevenness and has a good surface appearance, it is preferable to use inorganic oxide nanoparticles that are not in an aggregated state.

[0054] <Other components in the hard coating composition> The hard coating composition preferably includes a leveling agent in addition to the (meth)acryloyl polymer and inorganic oxide nanoparticles described above. For example, fluorinated additives or silicone additives can be used as leveling agents.

[0055] As fluorinated additives, DIC's MEGAFACE RS-56, RS-75, RS-76-E, RS-76-NS, RS-78, RS-90, and NEOS's Ftergent 710FL, 220P, 208G, 601AD, 602A, 650A, 228P, and Ftergent240GFTX-218 (all of which are oligomers with UV-reactive groups containing fluorine groups) can be used. Among these, Ftergent 601AD is preferred as a fluorinated additive.

[0056] In addition, as an organosilicon additive, BYK-UV3500 and BYK-UV3505 (both are polyether-modified polydimethylsiloxanes containing acrylic groups) manufactured by BYK-Chemie can be used. Among these, BYK-UV3500 is preferred as an organosilicon additive.

[0057] The hard coating composition preferably contains a leveling agent in an amount of 0.1% to 10% by weight based on the total weight of the hard coating composition. More preferably, the leveling agent content in the hard coating composition is 0.5% to 7% by weight, and even more preferably 1% to 5% by weight.

[0058] Furthermore, the curable hard coating composition can be energy-curable or thermosetting, preferably energy-curable, and more preferably UV-curable. Therefore, the hard coating composition preferably also contains a photopolymerization initiator. As a photopolymerization initiator, IRGACURE 184 (1-hydroxy-cyclohexyl-phenyl-one), IRGACURE 1173 (2-hydroxy-2-methyl-1-phenyl-propane-1-one), IRGACURE TPO (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide), IRGACURE 819 (bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide), EsacureONE (oligomeric (2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]acetone), etc., are preferred as photopolymerization initiators from the viewpoint of heat resistance.

[0059] The hard coating composition may contain, for example, a photopolymerization initiator at a concentration of 1% to 6% by weight based on the total weight of the hard coating composition. More preferably, the content of the photopolymerization initiator in the hard coating composition is 2% to 5% by weight, and even more preferably 3% to 4% by weight.

[0060] The hard coating composition may also contain other additives, such as at least one additive selected from heat stabilizers, antioxidants, flame retardants, flame retardant additives, ultraviolet absorbers, release agents, and colorants. Antistatic agents, fluorescent whitening agents, antifogging agents, flow improvers, plasticizers, dispersants, antibacterial agents, etc., may also be added to the hard coating composition, provided that the desired physical properties are not significantly impaired.

[0061] In the hard coating composition, it is preferable to contain 60% by mass or more of (meth)acryloyl polymer and inorganic oxide nanoparticles, more preferably 80% by mass or more, and particularly preferably 90% by mass or more. Therefore, the content of components other than the two main components mentioned above in the hard coating composition is preferably less than 40% by mass, more preferably less than 20% by mass, and particularly preferably less than 10% by mass.

[0062] <Preparation of Hard Coating Composition> The hard coating composition is manufactured by blending the aforementioned (meth)acryloyl polymer, inorganic oxide nanoparticles, and other materials. For example, the components, such as the (meth)acryloyl polymer, are mixed using a roller, and then melt-blended using an extruder to produce the (meth)acryloyl polymer. The resin composition is not limited to granular form and can be in the form of flakes, powder, or blocks.

[0063] <Properties of the Hard Coating Composition> (i) Exterior stemness The hard coating composition of the present invention exhibits excellent surface drying properties. Therefore, the uncured hard coating composition can maintain its intended shape even when in contact with other substances such as an operator's hands, and adhesion of the hard coating composition to the surface of the contacting substance can be prevented. Thus, by utilizing the hard coating composition with excellent surface drying properties, after being shaped into a form suitable for various applications, it is easy to perform the curing process. Furthermore, it is also easy to directly store the uncured hard coating composition in a prescribed shape or to facilitate its distribution.

[0064] In contrast, in resin compositions with poor surface drying properties, such as those mainly composed of low molecular weight oligomers, a curing process is required before molding into a shape suitable for various applications, thus revealing a tendency for poor formability.

[0065] (ii) Gloss (appearance) after masking film peeling In the hard coating composition of the present invention, when processed into a film in an uncured state, and when the film is stacked and peeled off, the occurrence of unevenness on the film surface can be suppressed, and the gloss can be well maintained.

[0066] As will be described in detail below, the hard coating composition of the present invention has been confirmed in such evaluation tests to maintain a smooth surface and good gloss after the masking film has been peeled off.

[0067] (iii) Formability (pressure forming ability) The moldability of the uncured hard coating composition of the present invention is also excellent. The moldability of the hard coating composition is evaluated, for example, by applying the hard coating composition to the surface of the substrate layer and drying it, and then heating and press-molding the resulting laminated body in a mold having protrusions, and evaluating whether the sheet-like hard coating composition follows the protrusions and extends appropriately, and whether cracking occurs.

[0068] As will be described in detail below, the hard coating composition of the present invention was confirmed in such evaluation tests to be able to follow the protrusions and extend without cracking during pressure molding.

[0069] (iv) Scratch resistance After curing, the hard coating composition of the present invention can achieve high scratch resistance. As will be described in detail below, it has been confirmed that if a laminate of layers having the hard coating composition is cured to form a hard coating, the scratch resistance of the surface of the hard coating is superior to that of cured PMMA resin (polymethyl methacrylate resin) and lens resin.

[0070] (v) Hardness The cured hard coating composition exhibits high hardness. Specifically, when applied to a PMMA substrate and cured, it achieves a pencil hardness of B or higher according to the evaluation method of JIS K 5600-5-4:1999. More preferably, a pencil hardness of F or higher, and particularly preferably 2H or higher, can be achieved on the surface of the cured hard coating composition.

[0071] (vi) tightness The cured hard coating composition also exhibits excellent adhesion to the resin substrate. Specifically, as detailed below, when applied to a PMMA substrate and cured, the evaluation result determined by the evaluation method of JIS K 5600-5-6:1999 was 0, which is better than the evaluation results of 1 to 5.

[0072] [Laminated body membranes] The laminated film of the present invention is a film obtained by laminating a coating layer of the above-mentioned hard coating composition in an uncured state on any surface of a substrate layer containing a resin, preferably a coating layer composed of an uncured hard coating composition.

[0073] The substrate layer of the laminated film preferably comprises a resin, more preferably a thermoplastic resin. There is no particular limitation on the type of thermoplastic resin; various resins can be used, including polycarbonate (PC) resin, acrylic resins such as polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), triacetyl cellulose (TAC), polyethylene naphthalate (PEN), polyimide (PI), cyclic olefin copolymers (COC), norbornene-containing resins, polyethersulfone, cellophane, aromatic polyamides, etc. Among these options, the thermoplastic resin of the substrate layer preferably comprises at least polycarbonate resin.

[0074] The type of polycarbonate resin contained in the substrate layer of the laminated film is not particularly limited, as long as it is a resin containing a carbonate bond in the main molecular chain of a -[O-R-OCO]- unit (R is an aliphatic group, an aromatic group, or a group including both aliphatic and aromatic groups, and has a linear or branched structure). Polycarbonates with a bisphenol backbone are preferred, and polycarbonates with a bisphenol A backbone or a bisphenol C backbone are particularly preferred. As the polycarbonate resin, mixtures or copolymers of bisphenol A and bisphenol C can be used. By using a bisphenol C-based polycarbonate resin, such as a polycarbonate resin containing only bisphenol C, or a polycarbonate resin containing a mixture or copolymer of bisphenol C and bisphenol A, the hardness of the substrate layer can be improved.

[0075] In addition, the viscosity-average molecular weight of the polycarbonate resin is preferably 15,000 to 40,000, more preferably 20,000 to 35,000, and even more preferably 22,500 to 25,000.

[0076] Furthermore, the acrylic resin contained in the substrate layer of the laminated film is not particularly limited. Examples include polymethyl methacrylate (PMMA), homopolymers of various (meth)acrylates represented by methyl methacrylate (MMA), copolymers of PMMA or MMA with one or more other monomers, and resins obtained by mixing various of these resins. Among these, (meth)acrylates containing cyclic alkyl structures with low birefringence, low moisture absorption, and excellent heat resistance are preferred. Examples of the above-mentioned (meth)acrylate resins include ACRYPET (manufactured by Mitsubishi Rayon), DELPET (manufactured by Asahi Kasei Chemicals), and PARAPET (manufactured by Kuraray), but are not limited to these.

[0077] Furthermore, when using a laminate obtained by laminating the aforementioned acrylic resin onto a polycarbonate resin surface layer as a substrate, it is preferable to improve the surface hardness of the substrate layer.

[0078] In addition, the substrate layer of the laminated film may contain additives other than thermoplastic resin. These additives may include at least one selected from heat stabilizers, antioxidants, flame retardants, flame retardant additives, ultraviolet absorbers, release agents, and colorants. Furthermore, antistatic agents, fluorescent whitening agents, antifogging agents, flow improvers, plasticizers, dispersants, and antibacterial agents may also be added to the substrate layer.

[0079] In the substrate layer of the laminated film, it is preferable to contain 80% or more by mass of thermoplastic resin, more preferably 90% or more by mass, and particularly preferably 95% or more by mass of thermoplastic resin. Furthermore, in the thermoplastic resin of the substrate layer, it is preferable to contain 80% or more by mass of polycarbonate resin, more preferably 90% or more by mass, and particularly preferably 95% or more by mass of polycarbonate resin.

[0080] The thickness of the substrate layer of the laminated film is not particularly limited, but is preferably 30 to 1000 μm (1 mm), more preferably 50 to 700 μm, and particularly preferably 100 to 500 μm. Furthermore, two or more substrate layers can be provided. When multiple substrate layers are provided, the total thickness of the substrate layers is, for example, 100 to 1000 μm, preferably around 200 to 500 μm.

[0081] The laminated film of the present invention can be manufactured as follows. First, in the manufacture of the substrate layer, a material such as a resin composition is processed into a layer (sheet) shape using existing methods. For example, extrusion molding or casting molding methods can be used. As an example of extrusion molding, a method can be listed where granules, flakes or powders of a resin composition are melted and mixed in an extruder, extruded from a T-die or the like, and the resulting semi-molten sheet is pressed with rollers while being cooled and solidified to form a sheet.

[0082] Then, the coating composition is applied to the outer surface of the substrate layer having a single layer or multiple layers and dried to form a coating layer.

[0083] In the laminated film, the thickness of the substrate layer is preferably 0.1 mm to 1.0 mm. For example, the thickness of the substrate layer is 0.2 mm to 0.8 mm or 0.3 mm to 0.7 mm.

[0084] In the laminated film, the thickness of the coating layer is preferably 1.0 μm to 10 μm. The coating thickness is, for example, 2.0 μm to 8.0 μm or 3.0 μm to 5.0 μm.

[0085] The structure of a multilayer membrane is, for example, as follows Figure 1 As shown. In Figure 1 In the illustrated laminated film 10, a coating layer 12, mainly composed of a hard coating composition, preferably formed by a hard coating composition alone, is laminated on the surface of the PMMA layer side of the substrate layer having a polymethyl methacrylate layer (PMMA resin layer) 20 and a polycarbonate layer (PC resin layer) 22.

[0086] [Cured film] The cured film of the present invention is a film obtained by curing the above-described laminated film. That is, the laminated film has a curable coating layer, and curing the coating layer of the laminated film can obtain a cured film. Curing methods such as photocuring and thermal curing can be used.

[0087] As can be seen from the properties of the cured hard coating composition described above, the surface of the coating layer side of the cured film of the present invention has excellent properties. That is, the surface of the coating layer side of the cured film achieves high pencil hardness, preferably pencil hardness of B or higher according to JIS K5600-5-4:1999, high scratch resistance, and excellent adhesion, for example, adhesion with an evaluation result of 0 level in JIS K5600-5-6:1999.

[0088] Example The following embodiments further illustrate the present invention. However, the present invention is not limited to the following embodiments, and can be implemented in any way without departing from the spirit of the invention.

[0089] [Manufacturing of laminates] First, the coating composition (coating solution) is prepared by mixing the components listed in Table 2 below. The acryloyl polymers used here are as follows.

[0090] (a) Acryloyl-containing polymer A: Art cure RA-3602MI manufactured by Gensho Industrial. (In acrylic polymers containing double bonds in the side chain: (meth)acrylate equivalent 300 g / eq: double bond equivalent 300 g / eq) (b) Acryloyl polymer B: Osaka Organic Chemical Industry Star-501 (Denimally oriented polyacrylate (multi-branched polyacrylate with acrylate groups at the ends (dipentaerythritol hexaacrylate (DPHA) linked type) polyacrylate: (meth)acrylate equivalent 120 g / eq) (c) Acryloyl polymer C: Art cure OAP-5000 manufactured by Gensho Industrial. (In acrylic polymers containing double bonds in the side chain: (meth)acrylate equivalent 2000 g / eq: double bond equivalent 2000 g / eq) (d) Acryloyl polymer D: Art Resin UN-3320HC manufactured by Gensho Industrial. (Polyurethane acrylate oligomer: (meth)acrylate equivalent 250 g / eq) In addition, the inorganic oxide particles (nano silica) added to the coating solution are as follows.

[0091] Nano silica: MEK-AC-2140Z manufactured by Nissan Chemical Co., Ltd. (organosilicon sol (average particle size 10-15nm: surface-modified silica sol)) Then, MEK was added to the obtained mixture as a diluent, and a coating solution with a solid content of 30% by weight was coated on the PMMA side of the PC / PMMA co-extruded film (PC: Iupilon E-2000, manufactured by Mitsubishi Engineering Plastics Co., Ltd.; PMMA: ALTUGLAS V020, manufactured by Arkema Corporation; PMMA layer thickness 45μm; total thickness 0.3mm).

[0092] The coating process was performed using a #16 wire-wound bar, and the coating solution was dried at 120°C for 5 minutes. A coating layer of approximately 7 micrometers thickness was formed using the dried coating solution. The coating layer was then cured at 90% output using a Fusion H valve (Fusion UV Systems) with air supplied at 1.8 m / min. The UV irradiation conditions were 1000 mJ / cm². 2 .

[0093] [Evaluation of traits] The properties of the cured laminate obtained in this way, as well as the laminate in the state before the coating is dried and cured (uncured laminate), are evaluated as follows.

[0094] <Surface dryness in the uncured state> The surface dryness of uncured laminates is evaluated by touch assessment.

[0095] <Gloss (Appearance) of the masking film after peeling off in its uncured state> A test piece with a substrate layer consisting of a polycarbonate resin and a PMMA resin laminate was prepared. A hard coating composition was applied to the surface of the PMMA resin side of the substrate layer of the test piece in such a way that a coating layer with a thickness of 7 μm was formed by the hard coating composition, and the film was dried at 120°C for 5 minutes.

[0096] Then, a 30 μm thick polypropylene masking film is attached to the surface of the uncured coating, and 30 kg / m² of material is applied from the masking film. 2 After 24 hours of pressure, the masking film was peeled off, and the surface roughness Sa of the coating layer was measured using a Hitachi High Technology VS1530 scanning white interference microscope (according to ISO 25178).

[0097] Examples and comparative examples with a surface roughness Sa value of less than 0.01 μm were evaluated as having good appearance.

[0098] <Moldability in the uncured state (pressure molding property)> A test piece with a substrate layer consisting of a polycarbonate resin and a PMMA resin laminate was prepared. A hard coating composition was applied to the surface of the PMMA resin side of the substrate layer of the test piece in such a way that a coating layer with a thickness of 7 μm was formed by the hard coating composition, and the film was dried at 120°C for 5 minutes.

[0099] Then, in the sample of the laminate obtained by cutting it into 210mm×297mm×0.3mm (thickness), the laminate is preheated at 190°C for 40 seconds. The sample is placed in a mold containing a right-angled protrusion with a deep drawing height of 13mm and a length and width of 30mm, with the surface of the polycarbonate resin side of the substrate layer in contact with the mold. The laminate sample is then pressurized and formed using high-pressure air of 3.5MPa.

[0100] Examples and comparative examples in which the radius R of the area where the pressure-molded body contacts the right-angled part of the mold is within 3 mm and the coating layer on the pressure-molded body does not crack are evaluated as having good formability.

[0101] Furthermore, in the substrate layer of the laminate obtained as a composite of polycarbonate resin and PMMA resin, as described above, the thickness of the PMMA layer is 45 μm, and the overall thickness is 0.3 mm.

[0102] <Abrasion resistance after curing> On the surface of the cured coating, at 100 gf / cm 2 Under pressure, #0000 steel wool was repeatedly abraded 15 times. The absolute value of the haze change (ΔH) was calculated according to JIS K 7136:2000 for evaluation; this absolute value was the difference between the haze value measured before the abrasion test and the haze value measured after the abrasion test based on JIS K 7136:2000. Examples and comparative examples with ΔH values ​​below 3.0% were evaluated as having good abrasion resistance.

[0103] <Chemical resistance after curing> After curing, NEUTROGENA SPF100 was applied to the surface of the coating layer, and the appearance was visually inspected after 1 hour at 80°C. Examples and comparative examples with no surface abnormalities were evaluated as having good chemical resistance.

[0104] <Pencil Hardness After Curing> The test was conducted based on the conditions of JIS K 5600-5-4:1999, and the hardest pencils without scratches were evaluated.

[0105] <Seamless fit> The evaluation was conducted using the evaluation method of JIS K5600-5-6:1999. Examples and comparative examples with an evaluation result of 0 were evaluated as having good fit.

[0106] The results of the determination of the properties of the membranes of the laminates of each embodiment and comparative example are shown in Table 2.

[0107] [Table 2]

Claims

1. A hard coating composition, which is a curable hard coating composition, characterized in that, Include: (Methacrylamide) polymers having a double bond equivalent of 100–1000 g / eq and a weight-average molecular weight of 5,000–200,000, and Inorganic oxide nanoparticles in a non-agglomerated state, with an average particle size of 7 nm or larger and less than 50 nm, and with copolymeric groups on the surface. The hard coating composition comprises 50-70% by weight of the (meth)acryloyl polymer and 50-30% by weight of inorganic oxide nanoparticles, based on the total weight of the hard coating composition. In the hard coating composition, the content of components other than the (meth)acryloyl polymer and the inorganic oxide nanoparticles is less than 10% by mass.

2. The hard coating composition according to claim 1, characterized in that: The (meth)acryloyl polymer comprises repeating units as shown in formula (I). In the aforementioned formula (I), m is an alkylene group having 1 to 4 carbon atoms or a single bond. n is an alkyl group or hydrogen with 1 to 4 carbon atoms. p is a single bond or an alkylene group with 1 or 2 carbon atoms. q is an alkyl group or hydrogen that may contain at least one of the substituents selected from epoxy, hydroxyl, acryloyl, and methacryloyl groups, and has a total carbon number of 1 to 12.

3. The hard coating composition according to claim 2, characterized in that: In the above formula (I), m is an alkylene group with 1 or 2 carbon atoms. n is an alkyl group with 1 or 2 carbon atoms. p represents a single bond or a methylene group. q is an alkyl group or hydrogen group that may contain at least one of the substituents selected from glycidyl, hydroxyl and acryloyl groups, and has a total carbon number of 1 to 6.

4. The hard coating composition according to claim 2, characterized in that: The (meth)acryloyl polymer comprises at least one of the repeating units shown in formulas (II-a), (II-b), and (II-c) below. 。 5. The hard coating composition according to any one of claims 1 to 4, characterized in that: The inorganic oxide nanoparticles contain silicon dioxide with copolymeric groups on the surface.

6. The hard coating composition according to any one of claims 1 to 4, characterized in that: It also contains leveling agents.

7. The hard coating composition according to claim 6, characterized in that: The leveling agent contains fluorine-based additives or organosilicon-based additives.

8. The hard coating composition as claimed in claim 6 or 7, characterized in that: The hard coating composition contains less than 10% by weight of the leveling agent based on the total weight of the hard coating composition.

9. The hard coating composition according to any one of claims 1 to 4, characterized in that: It is a hard coating composition that is energy line curable.

10. The hard coating composition according to any one of claims 1 to 4, characterized in that: It also contains a photopolymerization initiator.

11. The hard coating composition according to any one of claims 1 to 4, characterized in that: The hard coating composition is applied to the PMMA resin side of a substrate layer obtained by laminating polycarbonate resin and PMMA resin, forming a coating layer with a thickness of 7 μm. The coating is then dried at 120°C for 5 minutes and cut into 210 mm × 297 mm × 0.3 mm (thickness) samples to obtain a laminated body sample. The laminate was preheated at 190°C for 40 seconds. The sample was placed in a mold with a deep drawing height of 13 mm and a right-angled protrusion with a length and width of 30 mm, with the polycarbonate resin side of the substrate layer in contact with the mold. The laminate sample was pressurized using high-pressure air of 3.5 MPa. At this time, the radius R of the area where the pressurized body contacts the right-angled protrusion of the mold is within 3 mm, and the coating layer on the pressurized body does not crack.

12. The hard coating composition according to any one of claims 1 to 4, characterized in that: The hard coating composition is applied to the PMMA resin side of a substrate layer obtained by laminating polycarbonate resin and PMMA resin, such that a coating layer with a thickness of 7 μm is formed by the hard coating composition, and then dried at 120°C for 5 minutes. A 30 μm thick polypropylene masking film is attached to the surface of the uncured coating, and a 30 kg / m² pressure is applied to the masking film. 2 After 24 hours of pressure, the surface roughness Sa of the coating layer after the masking film is peeled off is less than 0.01 μm.

13. A laminated membrane, characterized in that: A coating layer comprising the hard coating composition according to any one of claims 1 to 12 is included on a substrate layer comprising a resin.

14. The laminated membrane as described in claim 13, characterized in that: The thickness of the substrate layer is 0.1 mm to 1.0 mm, and the thickness of the coating layer is 1.0 μm to 10 μm.

15. A cured film, characterized in that: It is obtained by curing the laminated film as described in claim 13 or 14.

16. The cured film as described in claim 15, characterized in that: The surface of the coating layer has a pencil hardness of B or higher.

17. The cured film as described in claim 15 or 16, characterized in that: On the surface of the coating layer side, apply #0000 steel wool at 100 gf / cm. 2 Under pressure and repeated abrasion 15 times, the haze change (ΔH) of the coating before and after abrasion, as evaluated based on JIS K 7136:2000, is less than 3.0%.

18. The cured film as described in claim 15 or 16, characterized in that: The evaluation result for the adhesion of the coating layer side, as determined by JIS K 5600-5-6:1999, is 0.

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