Laminate for thermal molding, molded article using said laminate, and method for manufacturing molded article

Abstract

The present invention relates to a laminate for post-curing thermoforming, in which a substrate layer, an uncured hard coat layer, and a protective film are laminated in this order, and after the protective film is removed and the hard coat layer is cured, the laminate for post-curing thermoforming is obtained. The nanoindentation hardness (Hi) of the hard coating layer before the weather resistance test and the nanoindentation hardness (Hf) after the weather resistance test satisfy the following relationship. 0.9 Hi < Hf < 1.4 Hi

Description

Technical Field

[0001] The present invention relates to a laminate for thermoforming of a post-curing type, a molded article using the laminate, and a method for manufacturing the molded article. Background Art

[0002] Hitherto, plastic household appliances, automotive products, etc. have generally been manufactured by coating plastic molded articles as needed. However, since this method has a large environmental load, various methods have been studied, such as an insert molding method of a decorative film capable of thermoforming. In recent years, due to the increasing requirements for chemical resistance and scratch resistance of molded articles, the demand for a thermoforming laminate (for example, a film) with a hard coat has also increased significantly. A thermoforming laminate with a hard coat is usually manufactured by coating a hard coat liquid on a substrate and then curing it (Patent Document 1).

[0003] In a normal hard coat film, formability, chemical resistance, and / or scratch resistance are in a trade-off relationship with each other. That is, generally, if the formability is improved, the chemical resistance and / or scratch resistance will decrease; and if the chemical resistance and / or scratch resistance are improved, the formability will deteriorate. Therefore, in order to solve this problem, a post-curing type thermoforming laminate has been proposed in which a hard coat liquid is coated on a substrate, dried to form a hard coat, then formed in an uncured state, and the hard coat is cured by UV irradiation or the like after forming.

[0004] In order to prevent scratches and foreign matter entrapment, a protective film is attached to the surface of the hard coat of the post-curing type thermoforming laminate. Since the entrapment of foreign matter in the forming process significantly reduces the yield, it is necessary to form the thermoforming laminate in a clean environment and in a state where the protective film is attached.

[0005] However, in order to perform thermoforming, it is necessary to heat the temperature above the glass transition temperature (Tg) of the substrate of the thermoforming laminate to soften the laminate. If heating is performed until the above temperature in a state where a protective film is attached to an existing post-curing type thermoforming laminate, there will be a problem that the curing of the hard coat is still in progress and the thermoforming performance is greatly impaired.

[0006] In addition, in an existing post-curing type thermoforming laminate, if thermoforming is performed in a state where a protective film is attached, there will be a problem of transferring the protective film pattern and deteriorating the appearance.

[0007] For these reasons, in existing laminates for post-curing thermoforming, the protective film is usually peeled off before forming. For this reason, a laminate for thermoforming has been proposed that can solve the above problems and can obtain a formed body with excellent thermoformability, chemical resistance, scratch resistance, etc. that can be thermoformed in a state where the protective film is attached (Patent Document 2).

[0008] Moreover, in articles used in an environment exposed to sunlight, it is preferable that, in addition to the above properties, they also need to have weather resistance. That is, as long as a formed body with weather resistance can be manufactured using a laminate with a hard coat, it is possible to provide a product that does not easily deteriorate even when used in an environment exposed to sunlight.

[0009] Prior Art Documents Patent Documents Patent Document 1: Japanese Patent Application Laid-Open No. 2017-508828 Patent Document 2: International Publication No. 2021 / 157588 Summary of the Invention

[0010] Problems to be Solved by the Invention An object of the present invention is to provide a laminate for post-curing thermoforming that can obtain a formed body with excellent weather resistance.

[0011] Technical Solution for Solving the Problems The inventors of the present invention conducted in-depth research and successfully obtained a laminate for post-curing thermoforming in which, even when the hard coat was cured for weather resistance testing, the change in the nanoindentation hardness of the hard coat before and after the weather resistance test was very small. Using such a laminate for thermoforming will enable the production of a formed body with excellent weather resistance. The present invention is as follows, for example.

[0012] [1] A laminate for post-curing thermoforming, wherein the laminate for post-curing thermoforming is formed by sequentially laminating a base material layer, an uncured hard coat, and a protective film, After removing the protective film and curing the hard coat, the nanoindentation hardness (Hi) of the hard coat before the weather resistance test and the nanoindentation hardness (Hf) after the weather resistance test satisfy the following relationship: 0.9Hi < Hf < 1.4Hi The above nanoindentation hardness is measured at a temperature of 30°C in accordance with ISO14577-1, The above weather resistance test is carried out under the conditions of an illuminance of 50 mW / cm 2 , a blackboard temperature of 63°C, a relative humidity of 50%, and 50 hours (continuous irradiation).

[0013] [2] The laminate for post-curing thermoforming according to [1], wherein the hard coat contains a polymer having a (meth)acryloyl group and inorganic oxide nanoparticles, When the total of the polymer and the nanoparticles is 100 parts by weight, the content of the polymer having a (meth)acryloyl group in the hard coat is 40 to 99 parts by weight, and the content of the inorganic oxide nanoparticles is 1 to 60 parts by weight.

[0014] [3] The laminate for post-curing thermoforming according to [2], wherein the polymer having a (meth)acryloyl group has an acrylic group equivalent of 250 to 700 g / eq, and the inorganic oxide nanoparticles have an average particle diameter of 5 to 150 nm.

[0015] [3-1] The laminate for post-curing thermoforming according to [2] or [3], wherein the polymer having a (meth)acryloyl group has a weight-average molecular weight of 5,000 to 200,000.

[0016] [4] The laminate for post-curing thermoforming according to any one of [2] to [3-1], wherein the hard coat further contains a light stabilizer and / or an ultraviolet absorber, When the total of the polymer and the nanoparticles contained in the uncured hard coat is 100 parts by weight, the total content of the light stabilizer and / or the ultraviolet absorber is 0.1 to 10 parts by weight.

[0017] [4-1] The laminate for post-curing thermoforming according to any one of [2] to [4], wherein the hard coat further contains a leveling agent and / or a photoinitiator.

[0018] [5] The laminate for post-curing thermoforming according to any one of [1] to [4-1], wherein the nanoindentation hardness of the uncured hard coat at 30 °C is 200 N / mm 2 or more.

[0019] [5-1] The laminate for post-curing thermoforming according to any one of [1] to [5], wherein after removing the protective film to cure the hard coat, when reciprocally scraping 15 times with a pressure of 100 gf / cm 2 on the surface of the hard coat using steel wool, the haze change (ΔH) before and after scraping of the hard coat is 3.0% or less, and the haze change (ΔH) is evaluated according to JIS K 7136:2000.

[0020] [6] The post-curing type thermoformable laminate according to any one of [1] to [5-1], wherein the hard coat is an active energy ray curable hard coat.

[0021] [6-1] The post-curing type thermoformable laminate according to any one of [1] to [6], wherein the thickness of the hard coat is 1 to 10 μm.

[0022] [7] The post-curing type thermoformable laminate according to any one of [1] to [6-1], wherein the base material layer contains a polycarbonate resin.

[0023] [7-1] The post-curing type thermoformable laminate according to [7], wherein the base material layer contains a polycarbonate resin layer and an acrylic resin layer.

[0024] [8] A molded article, which is obtained by curing an uncured hard coat in a molding intermediate obtained by molding the post-curing type thermoformable laminate according to any one of [1] to [7-1].

[0025] [9] A method for manufacturing a molded article, comprising: a step of thermoforming the post-curing type thermoformable laminate according to any one of [1] to [7-1]; a step of removing a protective film from the post-curing type thermoformable laminate that has been subjected to the above thermoforming treatment; and a step of curing the hard coat exposed on the surface by removing the protective film.

[0026]

[10] The method for manufacturing a molded article according to [9], wherein the thermoforming is performed by insert molding.

[0027] Advantages of the Invention According to the present invention, it is possible to provide a post-curing type thermoformable laminate capable of obtaining a molded article having excellent weather resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a cross-sectional schematic view of an example of the thermoformable laminate of the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, the specific embodiments of the present invention will be described in detail with reference to the drawings.

[0030] According to an embodiment of the present invention, the post-curing type thermoformable laminate of the present invention is formed by sequentially laminating a substrate layer, an uncured hard coat, and a protective film. After removing the protective film and curing the hard coat, the nanoindentation hardness (Hi) before the weather resistance test and the nanoindentation hardness (Hf) after the weather resistance test of the hard coat satisfy the following relationship: 0.9Hi < Hf < 1.4Hi wherein the nanoindentation hardness is measured according to ISO14577-1 at a temperature of 30°C, and the weather resistance test is carried out under the conditions of an illuminance of 50 mW / cm 2 , a blackboard temperature of 63°C, a relative humidity of 50%, and 50 hours (continuous irradiation).

[0031] The inventors have successfully obtained a post-curing type thermoformable laminate in which, when the cured hard coat is subjected to a weather resistance test, the change in the nanoindentation hardness of the hard coat before and after the weather resistance test is very small. Moreover, it has been confirmed that the adhesion between the hard coat of the molded body obtained from the laminate having such a hard coat and the substrate layer is excellent, and peeling of the hard coat from the substrate layer due to the weather resistance test can be effectively suppressed. Generally, when attempting to increase the hardness in order to ensure the strength and scratch resistance of the hard coat, the adhesion between the hard coat and the substrate layer often deteriorates due to the curing shrinkage (size change) during the curing of the hard coat. Despite this, the inventors have found a hard coat that can ensure the required hardness and scratch resistance and also has excellent adhesion to the substrate layer even after the weather resistance test. The molded body with excellent weather resistance can be applied to articles used in an environment exposed to sunlight (such as interior and exterior trim members of automobiles, building materials, mobile devices, etc.).

[0032] The inventors have considered various factors that can suppress the change in the nanoindentation hardness of the hard coat before and after the weather resistance test, and examples include the composition and curing conditions of the hard coat that suppress curing shrinkage. For example, the inventors believe that the difference in the degree of curing shrinkage caused by the composition of the hard coat and the type and amount of additives used will affect the degree of curing shrinkage, and as a result, will affect the change amount of the nanoindentation hardness before and after the weather resistance test. As a specific example, a light stabilizer and / or an ultraviolet absorber contained in the hard coat can be cited. The inventors speculate that they have the function of capturing free radicals generated by the weather resistance test and suppressing the polymerization and curing shrinkage of the resin contained in the hard coat. In addition, the inventors speculate that in the later stage of the weather resistance test, the light stabilizer and the ultraviolet absorber also have the function of suppressing embrittlement (decrease in indentation hardness) caused by the auto-oxidation of the hard coat. However, the influencing factors are not limited to this.

[0033] Hereinafter, each component, manufacturing method, physical properties, uses, etc. of the post-curing type thermoformable laminate according to the embodiment will be described in detail.

[0034] [1] Thermoformable laminate The thermoformable laminate according to the embodiment of the present invention includes (a) a base material layer, (b) a curable (uncured) hard coat, and (c) a protective film, which are laminated in the order of (a) the base material layer, (b) the hard coat, and (c) the protective film. That is, in the thermoformable laminate of the embodiment of the present invention, the (a) base material layer is laminated on one surface of the (b) hard coat, and the (c) protective film is laminated on the other surface of the (b) hard coat. Moreover, the laminate according to the embodiment of the present invention may further include layers other than the above (a) to (c), and each of the layers (a) to (c) may also include multiple layers.

[0035] Figure 1 It is a schematic cross-sectional view of an example of the thermoformable laminate according to the embodiment. In Figure 1 it, the laminate 10 has a structure in which a hard coat 16 is laminated on a base material layer (for example, a base material layer including a polymethyl methacrylate layer (PMMA resin layer) 20 and a polycarbonate layer (PC resin layer) 22), and a protective film 12 is further laminated thereon. That is, the surface of the hard coat 16 is protected by the protective film 12. When the base material layer includes two or more layers as described above, its configuration is not particularly limited.

[0036] The thermoformable laminate according to the embodiment of the present invention is of the post-curing type. Therefore, the thermoformable laminate according to the embodiment of the present invention has an uncured hard coat, and can also perform the forming process in a state where the hard coat is uncured. Specifically, when performing the forming process in a state where the hard coat is uncured, after the thermoformable laminate is formed into a desired shape and the protective film is peeled off, the hard coat exposed on the surface can be cured. Although it is also possible to perform the forming after peeling off the protective film, as described later, according to the embodiment of the present invention, the forming can be performed in a state where the protective film is attached. The curing means of the hard coat depends on the material of the hard coat, and examples thereof include curing by active energy rays or heat curing. In the past, if the forming was performed after the hard coat was cured, there would be a problem that fine cracks occurred in the hard coat, but if a post-curing type thermoformable laminate was used to perform the forming in a state where the hard coat was uncured, such problems would not occur. In addition, the thermoformable laminate according to the embodiment of the present invention can be well formed in a state where the protective film is attached, so that damage to the hard coat and entrainment of foreign matter during the forming can be prevented.

[0037] Hereinafter, each layer of the laminate for thermoforming according to the embodiments of the present invention will be described in turn. In this specification, the liquid mixture for the hard coat applied on the substrate layer is referred to as "hard coat composition", the state after the hard coat composition is applied on the substrate layer and dried but before curing is referred to as "uncured hard coat", and the state in which the hard coat is cured by active energy rays, heat, etc. is referred to as "cured hard coat". In addition, the cured state includes a semi-cured state that is not completely cured.

[0038] [2] Substrate layer The substrate layer is preferably laminated in contact with the surface on the opposite side of the protective film of the hard coat. However, it is not limited thereto, and other layers may be disposed between the substrate layer and the hard coat.

[0039] The substrate layer preferably contains a thermoplastic resin. The type of the thermoplastic resin is not particularly limited, and various resins such as polycarbonate (PC) resin, acrylic resins such as polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), triacetyl cellulose (TAC), polyethylene naphthalate (PEN), polyimide (PI), cycloolefin copolymer (COC), resin containing norbornene, polyethersulfone, cellophane, and aromatic polyamide can be used. The substrate layer preferably contains at least one polycarbonate resin among the above thermoplastic resins, and more preferably contains an aromatic polycarbonate resin from the viewpoints of toughness and heat resistance.

[0040] The type of the polycarbonate resin is not particularly limited as long as the main chain of the molecule contains a carbonate bond -[O-R-OCO]-(R is an aliphatic group, an aromatic group, or a group containing both an aliphatic group and an aromatic group, and may be a straight-chain structure or a branched-chain structure). Among them, a polycarbonate resin having a bisphenol skeleton is preferred, and a bisphenol A type polycarbonate resin having a bisphenol A skeleton or a bisphenol C type polycarbonate resin having a bisphenol C skeleton is particularly preferred. As the polycarbonate resin, a mixture of a bisphenol A type polycarbonate resin and a bisphenol C type polycarbonate resin, or a copolymer of bisphenol A and bisphenol C can be used. In order to improve the hardness of the substrate layer, a bisphenol C type polycarbonate resin (for example, a polycarbonate resin made of bisphenol C, a mixture of a bisphenol A type polycarbonate resin and a bisphenol C type polycarbonate resin, or a copolymer of bisphenol A and bisphenol C) is preferably used.

[0041] As the thermoplastic resin contained in the base material layer, an acrylic resin is also preferred. Specifically, examples include, but are not particularly limited to, homopolymers of various (meth)acrylates represented by poly(methyl methacrylate) (PMMA) and methyl methacrylate (MMA), or copolymers of PMMA, MMA, and monomers forming them with one or more other monomers. In addition, mixtures of multiple resins can also be used. Among them, (meth)acrylates containing a cycloalkyl structure with low birefringence, low hygroscopicity, and excellent heat resistance are preferred. Examples of such (meth)acrylates include, but are not limited to, ACRYPET (manufactured by Mitsubishi Rayon), Delpet (manufactured by Asahi Kasei Chemicals), and Parapet (manufactured by Kuraray).

[0042] Moreover, the base material layer can be formed by multiple layers with different compositions. For example, a base material layer containing the above-mentioned polycarbonate resin layer and acrylic resin layer can be used. The base material layer with a multi-layer composition is not limited to a double-layer structure and can also be three layers or more. For example, when using a base material layer containing a polycarbonate resin layer and an acrylic resin layer, it is preferred to further laminate a hard coat on the acrylic resin side. By laminating a hard coat with excellent weather resistance and an acrylic resin layer on top of the polycarbonate resin layer with poor weather resistance, a film with excellent weather resistance can be obtained. By using a base material layer with a multi-layer structure including a polycarbonate resin layer and an acrylic resin layer, not only can the surface hardness of the base material layer be improved, but also the thermoformability of the base material layer can be maintained.

[0043] The viscosity-average molecular weight of the thermoplastic resin contained in the base material layer is preferably 15,000 to 40,000, more preferably 20,000 to 35,000, and further preferably 22,500 to 25,000.

[0044] In addition, the base material layer can also contain additives as components other than the thermoplastic resin. Examples of additives include, for example, heat stabilizers, antioxidants, flame retardants, flame retardant aids, ultraviolet absorbers, mold release agents, colorants, etc., and the base material layer may contain one or more of them. Moreover, antistatic agents, fluorescent brighteners, antifogging agents, flow improvers, plasticizers, dispersants, antibacterial agents, etc. can also be added to the base material layer.

[0045] The content of the thermoplastic resin in the base material layer is preferably 80% by mass or more, more preferably 90% by mass or more, and particularly preferably 95% by mass or more, relative to the mass of the base material layer. In addition, in the base material layer mainly composed of a polycarbonate resin, the proportion of the polycarbonate resin relative to the base material layer is preferably 80% by mass or more, more preferably 90% by mass or more, and particularly preferably 95% by mass or more. In the base material layer mainly composed of an acrylic resin, the proportion of the acrylic resin relative to the base material layer is preferably 80% by mass or more, more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

[0046] The thickness of the base material layer is preferably, but not particularly limited to, 0.10 mm to 1.0 mm. For example, the thickness of the base material layer is 0.15 mm to 0.80 mm, 0.18 mm to 0.60 mm, or 0.25 mm to 0.40 mm. By using the base material layer with such a thickness, a film with excellent moldability and hardness can be achieved.

[0047] In the case where the base material layer is composed of multiple layers, the thickness of each layer may be within the above range, or the overall thickness of the base material layer may be within the above range.

[0048] [3] Hard coat The composition of the hard coat is not particularly limited as long as the change in nanoindentation hardness before and after the weather resistance test falls within the set range described in this specification. As the material constituting the hard coat, for example, a radically curable resin or a thermosetting resin can be cited. In the case where the hard coat mainly contains such a curable resin, this case is preferred because the hard coat can be cured even without using a curing agent. The hard coat may also contain various additives for improving performance. As such additives, nanoparticle, light stabilizer, ultraviolet absorber, leveling agent, photoinitiator, etc. can be cited.

[0049] (1) Curable resin The hard coating preferably contains a radiation curable resin or a thermosetting resin, more preferably a radiation curable resin. As the radiation curable resin, any resin having radiation curable properties can be used. Examples of the radiation curable resin include (meth)acrylate polymers. More specifically, examples include epoxy (meth)acrylate polymers, urethane (meth)acrylate polymers, and polyester (meth)acrylate polymers. Particularly suitable is a polymer having a (meth)acryloyl group, such as a (meth)acrylate polymer having a (meth)acryloyl group. More specifically, examples include an epoxy (meth)acrylate polymer having a (meth)acryloyl group, a urethane (meth)acrylate polymer having a (meth)acryloyl group, and a polyester (meth)acrylate polymer having a (meth)acryloyl group. Radiation curable resins are readily available from various companies. Hereinafter, a polymer having a (meth)acryloyl group will also be referred to as a (meth)acryloyl polymer.

[0050] It should be noted that in this specification, (meth)acrylate refers to methacrylate and / or acrylate, and (meth)acryloyl refers to methacryloyl and / or acryloyl. Other similar notations are also interpreted in the above manner.

[0051] ・ Epoxy (meth)acrylate polymer The radiation curable resin can be, for example, an epoxy (meth)acrylate polymer. Among them, an epoxy (meth)acrylate polymer having a (meth)acryloyl group is preferred. The synthesis of epoxy (meth)acrylate is shown, for example, by formula (1). Epoxy (meth)acrylate can be obtained by adding acrylic acid or methacrylic acid having an unsaturated bond to an epoxide.

[0052] 。

[0053] In formula (1), R is an alkyl group having 1 to 12 carbon atoms or a hydrogen atom, and the alkyl group may be substituted with one or more substituents selected from an epoxy group, a hydroxyl group, an acryloyl group, and a methacryloyl group, and R' is a methyl group or a hydrogen atom.

[0054] The epoxy (meth)acrylate polymer can be synthesized, for example, by copolymerizing (meth)acrylic acid with glycidyl (meth)acrylate to form an epoxy resin having a (meth)acrylate backbone, and adding acrylic acid, methacrylic acid, etc. thereto. Its synthesis is shown, for example, by formula (2). Examples of applicable epoxy (meth)acrylate polymers include polymers having a repeating unit represented by the following formula (I). In formula (I), m is an alkylene group having 1 to 4 carbon atoms or a single bond; n is an alkyl group having 1 to 4 carbon atoms or a hydrogen atom; p is a single bond or an alkylene group having 1 or 2 carbon atoms; q is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms which may have one or more substituents selected from an epoxy group, a hydroxyl group, an acryloyl group, and a methacryloyl group.

[0055] In the above formula (I), preferably, m is an alkylene group having 1 or 2 carbon atoms; n is an alkyl group having 1 or 2 carbon atoms; p is a single bond or a methylene group; q is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have one or more substituents selected from an epoxy group, a hydroxyl group, and an acryloyl group. More preferably, m is a methylene group, n is a methyl group, p is a single bond, and q is an alkyl group having 5 or less carbon atoms which may have one or more substituents selected from a methyl group or an epoxy group, or an alkyl group having 8 or less carbon atoms which may have one or more substituents selected from a hydroxyl group and an acryloyl group.

[0056] As specific examples of the repeating unit represented by formula (I), the repeating units represented by the following formula (II-a), formula (II-b), and formula (II-c) can be cited. When the epoxy (meth)acrylate polymer contains the repeating units of formula (II-a), formula (II-b), and formula (II-c), based on the total molar amount of the repeating unit of formula (II-a), the repeating unit of formula (II-b), and the repeating unit of formula (II-c), the proportion of the repeating unit of formula (II-a) is preferably 30 to 85 mol%, more preferably 40 to 80 mol%; the repeating unit of formula (II-b) is preferably 5 to 30 mol%, more preferably 10 to 25 mol% based on the above total molar amount; further, the repeating unit of formula (II-c) is preferably 10 to 40 mol%, more preferably 10 to 35 mol% based on the above total molar amount.

[0057] Moreover, the molar ratio of the repeating unit (II-a), the repeating unit of formula (II-b), and the repeating unit of formula (II-c) is preferably 4.5 to 5.5:1.5 to 2.5:2.5 to 3.5, for example, about 5:2:3.

[0058] ・Urethane (meth)acrylate polymer The polymer having a (meth)acryloyl group may be a urethane (meth)acrylate polymer. Specific examples of the urethane (meth)acrylate polymer are as follows.

[0059] Isocyanate compound As the isocyanate compound, for example, it is an aromatic isocyanate which may have an alkyl substituent (such as methyl), preferably an aromatic isocyanate having 6 to 16 carbon atoms, more preferably an aromatic isocyanate having 7 to 14 carbon atoms, and particularly preferably an aromatic isocyanate having 8 to 12 carbon atoms.

[0060] Although the isocyanate compound is preferably an aromatic isocyanate, an aliphatic or alicyclic isocyanate may also be used.

[0061] Specific examples of the isocyanate compound include, for example, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, polyphenylmethane polyisocyanate, modified diphenylmethane diisocyanate, hydrogenated benzene dimethyl diisocyanate, benzene dimethyl diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, tetramethylbenzene dimethyl diisocyanate, isophorone diisocyanate, norbornene diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, phenylene diisocyanate, lysine diisocyanate, lysine triisocyanate, naphthalene diisocyanate and other polyisocyanates or trimer compounds or tetramer compounds of these polyisocyanates, biuret-type polyisocyanates, water-dispersible polyisocyanates (such as "Aquanate 100", "Aquanate 110", "Aquanate 200", "Aquanate 210", etc. manufactured by Nippon Polyurethane Industry Co., Ltd.), or reaction products of these polyisocyanates and polyols.

[0062] Among these isocyanate compounds, particularly preferred are diphenylmethane diisocyanate, toluene diisocyanate, naphthalene diisocyanate, trimethylolpropane (TMP) adduct of toluene diisocyanate, isocyanurate of toluene diisocyanate, TMP adduct of xylene diisocyanate, and dicyclohexylmethane diisocyanate (H12MDI), isophorone diisocyanate (IPDI), xylene diisocyanate (XDI), etc. represented by the following formula. Acrylate compound As the acrylate compound for forming a urethane (meth)acrylate polymer having a molecular structure containing a cyclic skeleton, for example, pentaerythritol triacrylate (PETA), dipentaerythritol pentaacrylate (DPPA), (meth)acrylic acid hydroxypropyl ester (acrylic acid hydroxypropyl ester; HPA), etc. can be cited.

[0063] In addition, as the acrylate compound, a compound having (meth)acryloyloxy and a hydroxyl group, for example, a monofunctional (meth)acryloyl-based compound having a hydroxyl group, may also be used.

[0064] As the monofunctional (meth)acryloyl compound having a hydroxyl group, examples thereof include mono(meth)acrylate containing a hydroxyl group {for example, hydroxyalkyl (meth)acrylate [such as hydroxy C2-20 alkyl (meth)acrylate like 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, preferably hydroxy C2-12 alkyl (meth)acrylate, more preferably hydroxy C2-6 alkyl (meth)acrylate], mono(meth)acrylate of polyalkylene glycol [such as monoethylene glycol mono(meth)acrylate, monoethylene glycol mono(meth)acrylate, etc., mono(meth)acrylate of poly C2-4 alkylene glycol], mono(meth)acrylate of polyhydric alcohol having 3 or more hydroxyl groups [such as glycerol mono(meth)acrylate, trimethylolpropane mono(meth)acrylate, etc., mono(meth)acrylate of alkane polyol, mono(meth)acrylate of polymer of alkane polyol like diglycerol mono(meth)acrylate]}, N-hydroxyalkyl (meth)acrylamide (such as N-hydroxymethyl (meth)acrylamide, N-(2-hydroxyethyl) (meth)acrylamide, etc., N-hydroxy C1-4 alkyl (meth)acrylamide), adducts obtained by adding the hydroxyl group of these compounds (such as (meth)acrylate of hydroxyalkyl) with lactone (such as C4-10 lactone like ε-caprolactone) (such as adducts added with about 1 to 5 moles of lactone), etc.

[0065] It should be noted that these acrylate compounds can be used alone or in combination of two or more.

[0066] As a specific preferred example of the compound for forming (meth)acryloyloxy, 2-hydroxy-3-phenoxypropyl acrylate can be cited.

[0067] Among them, pentaerythritol triacrylate (PETA), dipentaerythritol pentaacrylate (DPPA), and hydroxypropyl (meth)acrylate (hydroxypropyl acrylate, HPA) are particularly preferred.

[0068] Copolymer of isocyanate compound and acrylate compound As specific preferred examples of the copolymer of isocyanate compound and acrylate compound, that is, urethane (meth)acrylate polymer, there can be cited copolymers of xylene diisocyanate (XDI) and pentaerythritol triacrylate (PETA), copolymers of XDI and dipentaerythritol pentaacrylate (DPPA), copolymers of dicyclohexylmethane diisocyanate (H12MDI) and PETA, copolymers of isophorone diisocyanate (IPDI) and PETA, copolymers of XDI and hydroxypropyl (meth)acrylate (HPA), etc.

[0069] In addition, as a urethane (meth) acrylate polymer containing a cyclic skeleton molecular structure, in addition to the above-mentioned isocyanate compounds and acrylate compounds, copolymers using polyol compounds can also be cited. A polyol compound (polyol) is a compound having two or more hydroxyl groups in each molecule, and examples thereof include the following compounds. That is, as examples of polyol compounds, ethylene glycol, propylene glycol, diethylene glycol, trimethylene glycol, tetraethylene glycol, triethylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-butanediol, 3-methyl-1,2-butanediol, 1,2-pentanediol, 1,5-pentanediol, 1,4-pentanediol, 2,4-pentanediol, 2,3-dimethyltrimethylene glycol, tetramethylene glycol, 3-methyl-4,3-pentanediol, 3-methyl-4,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,6-hexanediol, 1,5-hexanediol, 1,4-hexanediol, 2,5-hexanediol, neopentyl glycol, neopentyl glycol hydroxypivalate and other diols, these diols adducted with lactones such as ε-caprolactone, polyester diol compounds such as bis(2-hydroxyethyl) terephthalate, polyether diol compounds such as epoxyalkylene adducts of bisphenol A, polyethylene glycol, polypropylene glycol, polybutylene glycol, α-olefin epoxides such as propylene oxide and butylene oxide, monoglycidyl compounds such as Cardura E10 (synthetic highly branched saturated fatty acid glycidyl ester manufactured by Shell Chemical Company), glycerol, trimethylolpropane, trimethylolethane, diglycerol, triglycerol, 1,2,6-hexanetriol, pentaerythritol, dipentaerythritol, sorbitol, mannitol and other alcohols with three or more hydroxyl groups, these alcohols with three or more hydroxyl groups adducted with lactones such as ε-caprolactone, polyester polyol compounds, alicyclic polyols such as 1,4-cyclohexanedimethanol, tricyclodecane dimethanol, hydrogenated bisphenol A, hydrogenated bisphenol F, hydrogenated bisphenol A, hydrogenated bisphenol F, etc.

[0070] As the polyol structural unit, a urethane (meth) acrylate polymer containing a structural unit derived from tricyclodecane dimethanol (TCDDM) represented by the following formula is preferably used. As specific preferred examples of the urethane (meth) acrylate polymer containing a polyol structural unit, copolymers of tricyclodecane dimethanol (TCDDM), IPDI and PETA, copolymers of TCDDM, H12MDI and PETA, copolymers in which PETA is replaced with DPPA or copolymers using PETA and DPPA at the same time, copolymers of TCDDM, xylene diisocyanate (XDI) and hydroxypropyl (meth) acrylate (HPA), etc. can be cited.

[0071] In addition to isocyanate compounds and compounds having (meth)acryloyloxy and hydroxyl groups, the urethane (meth)acrylate polymer containing structural units derived from polyol compounds preferably contains at least a component represented by the following formula (i).

[0072] (A3)-O(OC)HN-A2-HN(OC)-O-A1-O-(CO)NH-A2-NH-(CO)O-(A3)・・・(i) In formula (i), A1 is an alkylene group derived from the above polyol compound; A2 are each independently an alkylene group derived from the above isocyanate compound; A3 are each independently an alkyl group derived from the above compound having (meth)acryloyloxy and hydroxyl groups.

[0073] Examples of the compound for forming A3 include 2-hydroxy-3-phenoxypropyl acrylate.

[0074] As other specific examples of the urethane (meth)acrylate polymer, the following compounds containing structural units derived from ethylene glycol, pentaerythritol triacrylate, and isophorone diisocyanate can be cited. In the following formula, n is an integer of 0 to 10, preferably an integer of 1 to 5, and more preferably an integer of 1 to 3. In the urethane (meth)acrylate polymer, the ratio of the structural units derived from the compound having (meth)acryloyloxy and hydroxyl groups to the structural units derived from the isocyanate compound is preferably 99:1 to 30:70 (weight ratio), more preferably 97:3 to 60:40, and further preferably 95:5 to 80:20.

[0075] (Urethane (meth)acrylate polymer containing acrylate) As a preferred specific example of the urethane (meth)acrylate polymer, a polymer containing structural units derived from urethane (meth)acrylate and structural units derived from (meth)acrylate can be cited. As a more preferred specific example of such a urethane (meth)acrylate polymer, a polymer containing structural units derived from a hexafunctional urethane (meth)acrylate and structural units derived from a bifunctional (meth)acrylate can be cited.

[0076] (Hexafunctional)urethane acrylate As described above, the urethane (meth)acrylate polymer is preferably a polymer containing structural units derived from urethane (meth)acrylate, particularly hexafunctional urethane (meth)acrylate.

[0077] As a preferred example of the hexa-functional urethane acrylate, compounds represented by the following formulae can be cited, namely, reaction products of dicyclohexylmethane diisocyanate (H12MDI) and pentaerythritol triacrylate (PETA), reaction products of isophorone diisocyanate (IPDI) and PETA, etc. Specific examples of preferred products of these hexa-functional urethane acrylates can be cited, such as UN-3320HC (reaction product of H12MDI and PETA: manufactured by Negami Kogyo Co., Ltd.), CN-968 (reaction product of IPDI and PETA: manufactured by Sartomer Japan Co., Ltd.), CN-975 (manufactured by Sartomer Japan Co., Ltd.), etc.

[0078] , (Meth)acrylate (bifunctional (meth)acrylate, etc.) The (meth)acrylate structural unit that can form a urethane (meth)acrylate polymer is preferably a structural unit derived from a compound having 4 to 20 carbon atoms that may have substituents and contains at least one (meth)acryloyloxy group and at least one vinyl ether. The number of carbon atoms of the (meth)acrylate is preferably 6 to 18, more preferably 8 to 16. Examples of the substituent of the (meth)acrylate include an alkyl group, etc.

[0079] In addition, the (meth)acrylate is preferably bifunctional.

[0080] As the (meth)acrylate, 2-(2-vinyloxyethoxy)ethyl (meth)acrylate (2-(2-vinyloxyethoxy)ethyl acrylate: VEEA) represented by the following formula, for example, is preferably used. In the above formula, R is a hydrogen atom or a methyl group.

[0081] In the urethane (meth)acrylate polymer, the ratio of the structural unit derived from urethane acrylate and the structural unit derived from (meth)acrylate is preferably 99:1 to 30:70 (weight ratio), more preferably 97:3 to 60:40, and further preferably 95:5 to 80:20.

[0082] (Fluorine-containing urethane (meth)acrylate polymer) As the (meth)acrylate polymer, a fluorine-containing urethane acrylate polymer can be used. The fluorine-containing urethane acrylate polymer preferably contains at least a component represented by the following formula (ii).

[0083] (A3)-O(OC)HN-A2-HN(OC)-O-A1-O-(CO)NH-A2-NH-(CO)O-(A3) ··· (ii) In the above formula (ii), A1 may have substituents, preferably an alkylene group derived from a fluorinated diol having 8 or fewer carbon atoms, preferably 6 or fewer carbon atoms, for example, 1 to 4 carbon atoms. Examples of the substituents contained in the alkylene group of A1 include an alkyl group and the like.

[0084] In the above formula (ii), A2s are independent of each other and are alkylene groups derived from an aliphatic or alicyclic isocyanate having 4 to 20 carbon atoms which may have substituents. The number of carbon atoms of A2 is preferably 6 to 16, more preferably 8 to 12. Examples of the substituents of the alkylene group of A2 include an alkyl group and the like.

[0085] In addition, as the alicyclic isocyanate forming A2, for example, isophorone diisocyanate represented by the following formula can be cited. In the above formula (ii), A3s are independent of each other and are alkyl groups having 4 to 30 carbon atoms which contain at least one (meth)acryloyloxy group and may further have substituents. The number of carbon atoms of A3 is 6 to 20, more preferably 8 to 16. Examples of the substituents of the alkyl group of A3 include a branched alkyl group and the like. A3 preferably contains at least two (meth)acryloyloxy groups, and for example, may contain three (meth)acryloyloxy groups.

[0086] In addition, A3 is derived from, for example, pentaerythritol triacrylate represented by the following formula. As the fluorinated urethane acrylate polymer, a compound formed from the above-mentioned respective compounds is preferred, and the fluorinated urethane acrylate contains, for example, a compound represented by the following formula (IV). ・Polyester (meth)acrylate polymer The polymer having a (meth)acryloyl group may be a polyester (meth)acrylate polymer. Examples of the polyester (meth)acrylate polymer include polymers obtained by the dehydration condensation reaction of (meth)acrylic acid, a polycarboxylic acid (anhydride) and a polyol. Examples of the polycarboxylic acid (anhydride) used in such a dehydration condensation reaction include succinic acid (anhydride), adipic acid, maleic acid (anhydride), itaconic acid (anhydride), trimellitic acid (anhydride), pyromellitic acid (anhydride), hexahydrophthalic acid (anhydride), phthalic acid (anhydride), isophthalic acid, terephthalic acid and the like. In addition, examples of the polyol used in the dehydration condensation reaction include 1,4-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, dimethylolheptane, dimethylolpropionic acid, dimethylolbutyric acid, trimethylolpropane, bis(trimethylol)propane, pentaerythritol, dipentaerythritol and the like.

[0087] As the polyester (meth)acrylate polymer, specifically, ARONIX M-6100, ARONIX M-7100, ARONIX M-8030, ARONIX M-8060, ARONIX M-8530, ARONIX M-8050 (the above are the trade names of polyester (meth)acrylate oligomers manufactured by Toagosei Co., Ltd.), Laromer PE44F, Laromer LR8907, Laromer PE55F, Laromer PE46T, Laromer LR8800 (the above are the trade names of polyester (meth)acrylate oligomers manufactured by BASF Corporation), Ebecryl 80, Ebecryl 657, Ebecryl 800, Ebecryl 450, Ebecryl 1830, Ebecryl 584 (the above are the trade names of polyester (meth)acrylate oligomers manufactured by Daicel U.C.B. Ltd.), PHOTOMERR CC13-429, PHOTOMER 5018 (the above are the trade names of polyester (meth)acrylate oligomers manufactured by San Nopco Limited), etc. can be cited.

[0088] ・Other active energy ray curable resins As the active energy ray curable resin, (meth)acrylate polymers other than the above can also be used, for example, (meth)acrylate polymers without (meth)acryloyl groups, or (meth)acrylate polymers without (meth)acrylate skeletons, etc.

[0089] In addition, as the active energy ray curable resin, compounds other than (meth)acrylate compounds can also be used, for example, epoxy compounds, oxetane compounds, etc.

[0090] The resin contained in the hard coat can be one kind or two or more kinds. When the total of the resin and the nanoparticles is 100 parts by weight, the content of the resin in the hard coat is preferably 40 to 99 parts by weight, more preferably 50 to 95% by weight, and still more preferably 60 to 90 parts by weight.

[0091] When a polymer having a (meth)acryloyl group, preferably a (meth)acrylate polymer having a (meth)acryloyl group, is used as the active energy ray-curable resin, the polymer preferably has a (meth)acrylic acid group equivalent of 250 to 700 g / eq. The (meth)acrylic acid group equivalent of the polymer having a (meth)acryloyl group is preferably 250 to 700 g / eq, more preferably 300 to 600 g / eq. Herein, the (meth)acrylic acid group equivalent (g / eq) refers to the molecular weight that can be allocated to each (meth)acryloyl group as defined by [molecular weight / number of (meth)acryloyl groups].

[0092] In addition, the (meth)acrylate polymer as the active energy ray-curable resin preferably has a weight average molecular weight of 5,000 to 200,000. The weight average molecular weight of the (meth)acrylate polymer is preferably 10,000 to 150,000, more preferably 15,000 to 100,000, and still more preferably 20,000 to 50,000.

[0093] The weight average molecular weight can be measured according to the description in paragraphs

[0061] to

[0064] of JP-A-2007-179018. The details of the measurement method are shown below.

[0094] [Table 1] Measurement conditions for weight average molecular weight That is, first, a calibration curve showing the relationship between the elution time and the molecular weight of polycarbonate is prepared by the universal calibration method using polystyrene as the standard polymer. Then, the elution curve (chromatogram) of the (meth)acrylate polymer is measured under the same conditions as those of the above calibration curve. Next, the weight average molecular weight (Mw) is calculated based on the elution time (molecular weight) of the polycarbonate resin and the peak area (number of molecules) at that elution time. The weight average molecular weight is represented by the following formula (A), in which Ni means the number of molecules having a molecular weight of Mi.

[0095] Mw = Σ(NiMi 2 ) / Σ(NiMi).....(A) The properties such as the surface dryness (tack free) before curing and scratch resistance after curing of the hard coat containing the (meth)acrylate polymer having the above-mentioned (meth)acrylic acid equivalent and weight average molecular weight are good, and the curing and polymerization reactions can be carried out well. In addition, by using a polymer having a (meth)acryloyl group, the surface dryness (anti-sticking property) of the hard coat can be improved, and even when thermoforming is carried out in a state where a protective film is attached, the appearance deterioration can be suppressed. This is because the protective film is easily peeled off from the thermoformed laminate. It should be noted that the polymer having the (meth)acryloyl group is commercially available and can be easily obtained. For example, it can be purchased from companies such as Dainippon Ink, Kyoeisha Chemical, and DSP Gokyo Foods & Chemicals.

[0096] ‎ (2) Polyfunctional acrylate compound The hard coat may contain a pentaerythritol-based polyfunctional acrylate compound. As the polyfunctional acrylate compound having a plurality of acrylate groups, preferably three or more acrylate groups, for example, pentaerythritol tetraacrylate and dipentaerythritol hexaacrylate represented by the following formulas (3) and (4) can be cited. In addition, pentaerythritol triacrylate and the like can also be used.

[0097] , 。

[0098] When the total of the curable resin and the polyfunctional acrylate compound contained in the hard coat is 100 parts by weight, the content of the polyfunctional acrylate compound in the hard coat is preferably 70 parts by weight or less, more preferably 50 parts by weight or less, and further preferably 30 parts by weight or less. Thus, by adding the polyfunctional acrylate compound to the hard coat composition and reacting with the acryloyl group, glycidyl group (epoxy group), hydroxyl group, etc. contained in the side chain of the resin (for example, (meth)acrylate polymer), a hard coat having higher scratch resistance can be formed.

[0099] (3) Nanoparticles The hard coat may contain nanoparticles. Thereby, the scratch resistance and hardness of the hard coat can be improved. The nanoparticles can be either inorganic particles or organic particles, but inorganic nanoparticles are preferred, and inorganic oxide nanoparticles are more preferred. For example, metal oxide nanoparticles such as nano-silica, nano-alumina, nano-titanium dioxide, and nano-zirconia can be used. And nano-diamond and the like can also be used.

[0100] The hard coating preferably contains silica particles as nanoparticles. The nanoparticles contained in the hard coating are preferably treated with a surface treatment agent. Through surface treatment, inorganic nanoparticles can be stably dispersed in the hard coating composition, and in particular, can be stably dispersed in a resin (such as a (meth)acrylate polymer).

[0101] As the surface treatment agent for treating the nanoparticles, a compound having a substituent capable of bonding to the surface of the nanoparticles and a substituent having high compatibility with the components of the hard coating (such as a (meth)acrylate polymer, a polymer having a (meth)acryloyl group, etc.) in which the nanoparticles are to be dispersed is preferably used. For example, as the surface treatment agent, silane compounds, alcohols, amines, carboxylic acids, sulfonic acids, phosphonic acids, etc. can be used.

[0102] The inorganic nanoparticles preferably have polymerizable groups on their surfaces. The polymerizable groups can be introduced through the surface treatment of the inorganic nanoparticles. Specific examples of the polymerizable groups include vinyl groups, (meth)acrylic groups, free-radical polymerizable groups, etc.

[0103] The average particle size of the nanoparticles is preferably 1 to 150 nm, more preferably 10 to 100 nm, and particularly preferably 30 to 60 nm. It should be noted that the average particle size of the nanoparticles can be measured by observing the cross-section of the hard coating with an electron micrograph. For example, the average particle size can be obtained by taking a TEM image of the particle cross-section prepared by FIB processing, etc., measuring the diameter lengths of 50 observed particles, and calculating the average value. In the case where the particles are non-spherical, the average of the major axis and the minor axis is regarded as the diameter of the particle.

[0104] When the total of the resin and the nanoparticles contained in the uncured hard coating is set to 100 parts by weight, the hard coating preferably contains 1 to 60 parts by weight of nanoparticles, such as inorganic nanoparticles. More preferably, it contains 10 to 50 parts by weight of inorganic nanoparticles, and further preferably, it contains 20 to 40 parts by weight of inorganic nanoparticles.

[0105] (4) Light stabilizer The hard coating may contain a light stabilizer. Thereby, the deterioration of the resin caused by ultraviolet irradiation in the weather resistance test can be suppressed. As the light stabilizer, hindered amine compounds such as Tinuvin 123 (manufactured by BASF), Tinuvin 770DF (manufactured by BASF), Tinuvin 144 (manufactured by BASF), and LA-81 (manufactured by ADEKA) can be used.

[0106] When the total of the resin and the nanoparticles contained in the uncured hard coat is 100 parts by weight, the content of the light stabilizer in the hard coat is preferably 0.1 to 10 parts by weight, more preferably 0.1 to 7 parts by weight, and particularly preferably 0.3 to 5 parts by weight.

[0107] (5) Ultraviolet absorber The hard coat may contain an ultraviolet absorber. Thereby, deterioration of the resin caused by ultraviolet irradiation in the weather resistance test can be suppressed. As the ultraviolet absorber, DAINSORB-T0 (manufactured by Daiwa Kasei Co., Ltd.), Tinuvin405 (manufactured by BASF), Tinuvin 477 (manufactured by BASF), Tinuvin 479 (manufactured by BASF), Tinuvin 928 (manufactured by BASF), UVA-903KT (manufactured by BASF), etc. can be used.

[0108] When the total of the resin and the nanoparticles contained in the uncured hard coat is 100 parts by weight, the content of the ultraviolet absorber in the hard coat is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 10 wt%, and particularly preferably 1 to 10 wt%. When the hard coat contains both a light stabilizer and an ultraviolet absorber, when the total of the resin and the nanoparticles contained in the uncured hard coat is 100 parts by weight, the total content of the light stabilizer and the ultraviolet absorber is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 7 parts by weight, and particularly preferably 1 to 10 parts by weight.

[0109] (6) Levelling agent The hard coat may also contain a levelling agent. Thereby, the levelling property, stain resistance, and abrasion resistance of the hard coat are improved. As the levelling agent, silicone-based additives, fluorine-based additives, etc. are preferably used. As the fluorine-based compound contained in the fluorine-based additive, for example, a compound having a perfluoropolyether bond can be cited. The fluorine-based additive can be synthesized by itself or easily obtained as a commercial product. For example, the MEGAFACE RS series of DIC, the KY series of Shin-Etsu Chemical Co., Ltd., the OPTOOL series of Daikin, etc. can be used.

[0110] As the silicone-based compound contained in the silicone-based additive, a compound having a polyalkylsiloxane bond can be cited. The silicone-based additive can be synthesized by itself or easily obtained as a commercial product. For example, the KP series of Shin-Etsu Silicone Co., Ltd., the BYK series of BYK Japan K.K., the TEGO Glide series of Evonik, etc. can be used.

[0111] When the total of the resin and the nanoparticles contained in the uncured hard coat is 100 parts by weight, the content of the leveling agent is preferably 0.001 to 10 parts by weight, more preferably 0.005 to 5 parts by weight, and particularly preferably 0.01 to 5 parts by weight.

[0112] (7) Photoinitiator As described above, the resin contained in the hard coat is preferably an energy ray curable or thermosetting (resin), more preferably an energy ray curable (resin), and particularly preferably an ultraviolet curable (resin). Therefore, the hard coat may further contain a photoinitiator. As the photoinitiator, IRGACURE 184 (1-hydroxycyclohexyl phenyl ketone), IRGACURE 1173 (2-hydroxy-2-methyl-1-phenyl-1-propanone), IRGACURE TPO (2,4,6-trimethylbenzoyl diphenylphosphine oxide), IRGACURE 819 (bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide), Esacure ONE (2-hydroxy-2-methyl-1-[4-(1-methylethenyl)phenyl]acetone oligomer), etc. can be used. Among them, from the viewpoint of heat resistance, Esacure One etc. are preferably used as the photoinitiator.

[0113] When the total of the resin and the nanoparticles contained in the uncured hard coat is 100 parts by weight, the content of the photoinitiator in the hard coat is preferably 1 to 6 parts by weight, more preferably 2 to 5 parts by weight, and particularly preferably 2 to 4 parts by weight.

[0114] (8) Other additives The hard coat may further contain other additives, for example, it may contain a heat stabilizer, an antioxidant, a flame retardant, a flame retardant aid, a release agent, a colorant, etc. As long as it does not significantly impair the required physical properties, an antistatic agent, a fluorescent brightening agent, an antifogging agent, a fluidity improver, a plasticizer, a dispersant, an antibacterial agent, etc. can also be added to the hard coat.

[0115] The dilution solvent used for preparing the hard coat composition can be used to adjust the viscosity, and its use is not particularly limited as long as it is a non-polymerizable solvent. By using the dilution solvent, the hard coat composition can be easily coated on the substrate layer.

[0116] Examples of the dilution solvent include toluene, xylene, ethyl acetate, propyl acetate, butyl acetate, methyl cellosolve, ethyl cellosolve, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, methanol, ethanol, isopropyl alcohol, butanol, butanol, diacetone alcohol, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, hexane, heptane, octane, decane, dodecane, propylene glycol monomethyl ether, 3-methoxybutanol, etc.

[0117] <Manufacture of Hard Coating> The hard coating is manufactured by coating a hard coating composition containing the materials described above on a layer adjacent to the hard coating (e.g., a substrate layer). For example, the hard coating composition can be prepared by mixing the respective materials and further stirring with a disperser.

[0118] As a coating method of the hard coating composition, examples include using a bar coater, a gravure coater, a die coater, dip coating, spray coating, etc. At this time, after coating the hard coating composition, drying is performed at a set temperature. As the drying temperature, it is preferably 30 to 150 °C, more preferably 60 to 130 °C. By drying at a temperature within the above range, the organic solvent can be removed from the hard coating, and deformation of other layers due to heating can be prevented.

[0119] The film thickness of the hard coating is preferably but not particularly limited to 1 to 10 μm, more preferably 2 to 7 μm. By setting the film thickness within the above range, the required properties of the hard coating can be obtained, and problems are less likely to occur in terms of adhesion, molding properties, etc.

[0120] <Physical Properties of Hard Coating> (i) Weather Resistance The weather resistance of the hard coating according to the embodiment of the present invention is excellent. That is, for example, even after the weather resistance test, the adhesion between the hard coating and the substrate layer can be maintained. This is because when the cured hard coating is subjected to the weather resistance test, the degree of change in the nanoindentation hardness of the hard coating before and after the weather resistance test is small. The nanoindentation hardness (Hi) of the cured hard coating before the weather resistance test and the nanoindentation hardness (Hf) after the weather resistance test satisfy 0.9Hi < Hf < 1.4Hi, preferably 0.95Hi < Hf < 1.4Hi, and more preferably 0.95Hi < Hf < 1.3Hi. In addition, the change rate of the nanoindentation hardness before and after the weather resistance test is preferably -10 to 40%, more preferably -5 to 40%, and particularly preferably -5 to 30%. Since the change amount of the nanoindentation hardness of the hard coating before and after the weather resistance test is within the above range, it can be considered that the hard coating has excellent adhesion to the substrate layer even after the weather resistance test, that is, a hard coating with excellent weather resistance. Satisfying 0.9Hi < Hf means that the hardness of the cured hard coating does not decrease significantly after the weather resistance test, and the weather resistance and adhesion of the post-cured thermoforming laminate are excellent. In addition, satisfying Hf < 1.4Hi means that the increase in hardness caused by the weather resistance test is not very large, and the scratch resistance does not decrease due to insufficient curing of the hard coating before the weather resistance test. The inventors believe that in the case where the increase in hardness after the weather resistance test is significantly large, there may be insufficient curing of the hard coating. In the current situation where high hardness is required to increase scratch resistance, the practical performance of the insufficiently cured hard coating is poor. It should be noted that the specific method for measuring the nanoindentation hardness is as described in the following examples.

[0121] (ii) Adhesion The hard coating according to the embodiment of the present invention has excellent adhesion to the substrate layer. Specifically, as described in detail later, when the hard coating is coated on a PMMA substrate and cured, and tested by the evaluation method of JIS K 5600-5-6: 1999, a hard coating can be obtained in which the cut edge is completely smooth and no peeling occurs in any grid.

[0122] (iii) Hardness The hard coating according to the embodiment of the present invention has a preferable nanoindentation hardness. That is, when measuring the nanoindentation hardness of the uncured hard coating, the nanoindentation hardness at 30 °C is 200 N / mm 2 or more (for example, 200 to 1,000 N / mm 2 , 210 to 800 N / mm 2 , 200 to 500 N / mm 2). The higher the nanoindentation hardness of the uncured hard coat, the better the scratch resistance of the obtained coating film in the uncured state and the appearance after injection molding. However, if the indentation hardness is too high, the molding performance will deteriorate. It should be noted that the specific measurement method of nanoindentation hardness is as described in the following examples.

[0123] (iv) Scratch resistance The hard coat according to the embodiment of the present invention has excellent scratch resistance, that is, it has the property of being not easily damaged. Specifically, after removing the protective film and curing the hard coat, when steel wool is reciprocally scratched 15 times on the surface of the hard coat under a pressure of 100 gf / cm 2 the haze change (ΔH) before and after scratching of the hard coat is 3% or less. The haze change is preferably 2% or less, more preferably 1% or less. The specific measurement method is as described in the following examples, and the haze change (ΔH) is evaluated based on JIS K 7136:2000.

[0124] [4] Protective film To prevent damage to the surface of the hard coat during processes such as molding, a protective film is provided on the surface of the hard coat. The protective film is adhered to the surface of the hard coat, for example, after coating a hard coat composition on a substrate layer and drying. The surface in contact with the hard coat of the protective film is preferably an adhesive surface having appropriate adhesive strength and is adhered to the surface of the hard coat. The composition of the protective film is not particularly limited, and a single-layer film having only an adhesive layer or a thin film having a two-layer structure of a substrate and an adhesive layer is preferred. In the two-layer structure protective film, the adhesive surface of the adhesive layer is laminated on the hard coat and is in contact with the hard coat. The protective film may also have a multi-layer structure including layers other than the above-mentioned substrate and adhesive layer. In addition, the protective film may be a single-layer structure, and even in the case of a single-layer structure protective film, the adhesive surface on the side of the hard coat has appropriate adhesive strength.

[0125] When the protective film has a substrate, the substrate preferably contains a thermoplastic resin, more preferably contains a polyolefin resin. As the polyolefin resin contained in the protective film, for example, polyethylene, polypropylene, etc. can be cited, and it can be a homopolymer or a copolymer. Among the polyolefin resins, polyethylene is also preferred.

[0126] As polyethylene, low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), very-low-density polyethylene (VLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), etc. can be used, and low-density polyethylene is preferred.

[0127] In addition, as the polyolefin copolymer, a copolymer formed from ethylene or propylene and a monomer capable of copolymerizing with these two can be used. Examples of the monomer capable of copolymerizing with ethylene or propylene include α-olefins, styrenic compounds, diene compounds, cyclic compounds, compounds containing an oxygen atom, and the like.

[0128] Examples of the α-olefin include 1-butene, 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, and the like. Examples of the styrenic compound include styrene, 4-methylstyrene, 4-dimethylaminostyrene, and the like. Examples of the diene compound include 1,3-butadiene, 1,5-hexadiene, 1,4-hexadiene, 1,7-octadiene. Examples of the cyclic compound include norbornene, cyclopentene, and the like. Examples of the compound containing an oxygen atom include hexenol, hexenoic acid, methyl octanoate, and the like. These copolymerizable monomers can be used alone or in combination of two or more. In addition, it can also be a copolymer of ethylene and propylene.

[0129] In addition, the copolymer can also be any one of alternating copolymerization, random copolymerization, and block copolymerization.

[0130] The polyolefin resin contained in the protective film substrate can also contain a modified polyolefin resin modified with a small amount of monomers containing a carboxyl group such as acrylic acid, maleic acid, methacrylic acid, maleic anhydride, fumaric acid, itaconic acid, and the like. The modification can generally be achieved by copolymerization or graft modification.

[0131] The content of the thermoplastic resin (such as polyolefin resin) of the protective film substrate relative to the total weight of the substrate is preferably 80% by weight or more, more preferably 90% by weight or more, and particularly preferably 95% by weight or more.

[0132] The adhesive layer of the protective film preferably contains an elastomer or a thermoplastic resin. Examples of the thermoplastic resin contained in the adhesive layer include polyolefin resins such as polyethylene and polypropylene, which can be homopolymers or copolymers. Among the polyolefin resins, polyethylene is preferred.

[0133] The content of the elastomer or thermoplastic resin in the adhesive layer of the protective film relative to the total weight of the adhesive layer is preferably 80% by weight or more, more preferably 90% by weight or more, and particularly preferably 95% by weight or more.

[0134] The thickness of the protective film is preferably 10 to 100 μm, more preferably 20 to 80 μm. When the protective film is composed of two or more layers, the total thickness of each layer is preferably within the above range.

[0135] In the protective film, in the state before being pasted onto the hard coat (not pasted), the surface roughness Sa value (ISO 25178) of the adhesive surface in contact with the hard coat is preferably 0.100 μm or less. In the state where the adhesive surface of the protective film is not pasted, the surface roughness Sa value is more preferably 0.090 μm or less, further preferably 0.080 μm or less, and particularly preferably 0.070 μm or less.

[0136] The adhesion value of the adhesive surface of the protective film with respect to the PMMA (polymethyl methacrylate resin layer) surface is preferably 5 (mN / 25 mm) or more and 5000 (mN / 25 mm) or less, and more preferably 9 (mN / 25 mm) or more and 3000 (mN / 25 mm) or less.

[0137] [5] Method for manufacturing a laminate for thermoforming The laminate for thermoforming according to the embodiment of the present invention is manufactured as follows. First, the material of the base material layer is processed into a layer (sheet-like) by a conventional method to produce the base material layer. For example, extrusion molding, casting molding, etc. can be used. As an example of extrusion molding, a method can be cited in which pellets, chips, or powders of the resin composition are melt-kneaded by an extruder and then extruded from a T-die head or the like, and the semi-molten sheet obtained is cooled and solidified in a state of being pressed between rollers to form a sheet.

[0138] Then, the hard coat composition obtained by mixing the above materials is coated on the outer surface of the obtained single-layer or multi-layer base material layer to form a hard coat.

[0139] Then, the above protective film is adhered onto the hard coat to manufacture a laminate for thermoforming.

[0140] [6] Thermoforming of the laminate The laminate for thermoforming according to the embodiment of the present invention is a post-curing type product. Therefore, the laminate for thermoforming according to the embodiment of the present invention can be formed in a state where the hard coat is not cured. Specifically, for example, after the laminate for thermoforming is formed into a desired shape (formed intermediate) and the protective film is peeled off, the hard coat exposed on the surface is cured. That is, according to one embodiment of the present invention, there is provided a formed body obtained by curing the uncured hard coat in the formed intermediate obtained by forming the post-curing type laminate for thermoforming. In addition, according to another embodiment of the present invention, there is provided a method for manufacturing a formed body, which includes a step of thermoforming a post-curing type laminate for thermoforming; a step of removing the protective film from the post-cured type laminate for thermoforming that has been thermoformed; and a step of curing the hard coat exposed on the surface by removing the protective film. As a method for forming the laminate, any method can be used as long as it is a method for thermoforming a film. For example, the substrate can be heated and thermoformed into a desired shape by compression air forming under atmospheric pressure, vacuum compression air forming under vacuum conditions, TOM forming, insert molding, etc. Among them, from the perspective of environmental load, insert molding is preferably used.

[0141] The forming temperature is mainly determined by the Tg (glass transition temperature) of the thermoplastic resin contained in the substrate layer. The forming temperature is preferably a temperature about 0 to 70 °C higher than the Tg of the thermoplastic resin contained in the substrate layer, and more preferably a temperature of about 20 to 40 °C. For example, when the laminate includes a substrate layer containing a conventional bisphenol A polycarbonate resin, it is optimal to perform forming in the range of 170 to 190 °C. Since the laminate for thermoforming according to the embodiment of the present invention is not likely to undergo a polymerization reaction (curing) of the hard coat at the above-mentioned temperature, it can be formed in a state where the protective film is attached. By performing a series of operations in a state where the protective film is attached, it will be possible to prevent damage to the hard coat and entrainment of foreign matter during forming.

[0142] [7] Manufacture of the formed body As described above, when the hard coat is cured after removing the protective film from the laminate that has been thermoformed according to a set shape, a formed body such as a cured film can be obtained. The technical means for curing the hard coat can be appropriately determined according to the composition of the hard coat. The obtained formed body can be used as, for example, a resin film laminate used in mobile devices, automotive interior components, household appliances, etc.

[0143] Examples The present invention will be described in detail below with reference to examples, but the content of the present invention is not limited to these examples.

[0144] (Example 1) 70 parts by weight of a UV-curable acrylate polymer (SMP-360A manufactured by Kyoeisha Chemical Co., Ltd., acrylate equivalent: 360 g / eq) was mixed with 30 parts by weight of nano-silica particles (silica sol MEK-AC-4130Y manufactured by Nissan Chemical Industries, Ltd.: average particle size 40 - 50 nm). Then, 3 parts by weight of a photoinitiator ESACURE-ONE, 4 parts by weight of a silicone leveling agent BYK-UV3575, and 1 part by weight of a hindered amine light stabilizer LA-81 (manufactured by ADEKA Corporation) were added. Then, cyclohexane as a diluting solvent was added to bring the solid component concentration to 25% by weight, and a hard coat composition was obtained after stirring.

[0145] As the substrate layer, a resin film laminated with a polycarbonate resin and a PMMA resin was prepared. The hard coat composition obtained as described above was coated on top of the substrate layer (on the acrylic resin side). The coating process was carried out using a bar coater, and the coated hard coat composition was dried at a temperature of 130°C for 3 minutes. The thickness of the formed hard coat was approximately 4 μm.

[0146] (Example 2) A thermoformable laminate was prepared in the same manner as in Example 1, except that 5 parts by weight of a UV absorber Tinuvin 477 (manufactured by BASF Corporation) was used instead of the light stabilizer LA-81.

[0147] (Example 3) A thermoformable laminate was prepared in the same manner as in Example 1, except that 1 part by weight of a light stabilizer Tinuvin 123 (manufactured by BASF Corporation) was used instead of the light stabilizer LA-81.

[0148] (Example 4) A thermoformable laminate was prepared in the same manner as in Example 1, except that 1 part by weight of a light stabilizer Tinuvin 770DF (manufactured by BASF Corporation) was used instead of the light stabilizer LA-81.

[0149] (Example 5) A thermoformable laminate was prepared in the same manner as in Example 1, using SMP-550AP (acrylate equivalent: 550 g / eq) manufactured by Kyoeisha Chemical Co., Ltd. as the UV-curable acrylate polymer and without using a light stabilizer.

[0150] (Example 6) A thermoformable laminate was prepared in the same manner as in Example 3, except that 30 parts by weight of MEK-ST-L (manufactured by Nissan Chemical Industries, Ltd., average particle size 45 nm) was used as the nano-silica particles.

[0151] (Comparative Example 1) Under the condition of not using a light stabilizer, a laminate for thermoforming was produced in the same manner as in Example 1 and Example 1.

[0152] <Physical property evaluation> Various physical property evaluations were carried out on the laminate for thermoforming prepared as described above, each constituent member of the laminate for thermoforming, and the cured hard coat as follows.

[0153] (1) Nanoindentation hardness of uncured hard coat Using an ultra-microindentation hardness testing device (ENT-NEXUS manufactured by Elingke Si Co., Ltd.), under the following conditions, the nanoindentation hardness after indentation in the thickness direction of the uncured hard coat obtained in the examples and comparative examples was measured. The measurement position was the central part of the hard coat, and the average value of the measurement values at 25 points was taken as the indentation hardness (N / mm 2 )

[0154] Indenter: Berkovich indenter (opposite vertex angle 65.03°) Surface detection: The loading load was set (0.5 mN) so that the displacement amount was 1 / 10 of the hard coat Loading curve: 10 seconds, 0.5 mN (linear) Holding time: 5 seconds 0.5 mN Unloading curve: 10 seconds, 0 mN (linear) Sample temperature: 30 °C Device setting environment: 23 °C, 50% RH Based on the above measurement results, according to the calculation in conformity with ISO14577-1 2002-10-01 Part1 (calculated by the built-in software of the device), the nanoindentation hardness was calculated.

[0155] It should be noted that the hardness of the sample changes due to the influence of moisture absorption, so the measurement was carried out after standing in an environment of 23 °C and 50% RH for more than 24 hours.

[0156] (2) Weather resistance test First, ultraviolet rays were irradiated on the hard coat of the laminate for thermoforming obtained in the examples and comparative examples to cure the hard coat. The ultraviolet irradiation was carried out using a conveyor belt type UV irradiation device ECS-401GX manufactured by EYE GRAPHICS Co., Ltd. under the condition of 700 mj / cm 2 (measurement wavelength 360 nm, high-pressure mercury lamp).

[0157] The weather resistance test was carried out using SUV-W161 manufactured by Iwasaki Electric Co., Ltd. under the following conditions.

[0158] Light source: Metal halide lamp Test environment: 63°C (blackboard temperature), 50% RH Illuminance: 50 mW / cm 2 (365 nm) Irradiation cycle: 50 hours (continuous irradiation) Illuminometer: Portable illuminometer (Model: UVP - 365 - 01) [High - energy ultraviolet illuminometer for metal halide lamp method testing, compliant with JIS C1613] Temperature control: Closed - loop circulation type (blackboard temperature PID method) Humidity control: Humidifier control using a capacitive humidity sensor Before and after the weather resistance test, the nano - indentation hardness of the cured hard coating was measured according to the method described in (1) above (ISO14577 - 1).

[0159] (3) Adhesion after weather resistance test The adhesion between the substrate layer and the hard coating of the sample after the weather resistance test carried out according to the method described in (2) above was evaluated. The adhesion was evaluated according to the evaluation method of JIS K5600 - 5 - 6:1999. The case where the incision edge was completely smooth and no peeling occurred in any grid was set as A, the case where the proportion of peeled grids was 40% or less was set as B, and the case where it was more than 40% was set as C for evaluation.

[0160] (4) Scratch resistance On the surface of the cured hard coating, a #0000 steel wool was used to reciprocally scratch the hard coating 15 times under a pressure of 100 gf / cm 2 The haze values before and after scratching were measured using a haze meter (HM - 150 manufactured by Murakami Color Co., Ltd.) according to JIS K 7136:2000. Then, the absolute value of the haze change (ΔH) before and after scratching was calculated. When the ΔH value was 3.0% or less, the scratch resistance was evaluated as good (A).

[0161] (5) Appearance after injection molding The laminated body for thermoforming prepared as described above was injection - molded according to the following steps, and the appearance after injection molding was evaluated.

[0162] (a) Compression air molding The thermoformable laminate in the uncured state was preheated at a temperature of 190°C for about 40 seconds. Immediately thereafter, the film was pressed against the mold using high-pressure air at 1.5 MPa to form the shape. At this time, a mold having a rectangular protrusion in the drawing height was used. It should be noted that in the compressed air molding, a rectangular mold with a horizontal and vertical dimension of 100 mm was used, and the radius R of the region in contact with the rectangular part of the mold was 2 mm and the height was 7 mm.

[0163] (b)Injection molding The shaped film was placed on the cavity surface of the injection molding die similar to the above compressed air molding, and molten thermoplastic resin was injected to produce a film insert molded product. As the injection resin, polycarbonate resin (IUPILON H-3000 manufactured by Mitsubishi Engineering-Plastics Corporation) was used. The mold temperature on the hard coat side during this period was set to 60°C or higher. The appearance after injection molding was evaluated, and the presence of appearance abnormalities such as whitening on the surface was confirmed.

[0164] The compositions and evaluation results of the thermoformable laminates according to the examples and comparative examples are shown together in Tables 2 and 3 below. In Table 2, the unit of each value is "parts by weight".

[0165] [Table 2] [Table 3] As can be seen from Tables 2 and 3, the hard coat of the example has excellent weather resistance, and as a result, its adhesion to the substrate layer is also high. The inventor believes that this performance is due to the small change in nanoindentation hardness before and after the weather resistance test. In addition, since the hard coat of the example also has excellent scratch resistance, it is not easily damaged. These properties will be very useful for products used in environments exposed to sunlight (such as automotive interior and exterior components, building materials, movable equipment, etc.). In addition, since the nanoindentation hardness of the uncured hard coat of the thermoformable laminate of the example is high, it can be regarded as a laminate having excellent scratch resistance in the uncured state and excellent appearance after injection molding, and also having excellent moldability.

[0166] Although several embodiments of the present invention have been described, these embodiments are merely examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are not only included in the scope and gist of the invention, but also included in the invention described in the claims and its equivalents.

[0167] Symbol description 10: Laminated body for thermoforming; 12: Protective film; 16: Hard coating; 20: Polymethyl methacrylate layer (substrate layer), 22: Polycarbonate layer (substrate layer).

Claims

1. A laminate for post-curing thermoforming, characterized in that, the laminate for post-curing thermoforming is formed by sequentially laminating a substrate layer, an uncured hard coat, and a protective film, after removing the protective film and curing the hard coat, the nanoindentation hardness Hi before the weather resistance test and the nanoindentation hardness Hf after the weather resistance test of the hard coat satisfy the following relationship: 0.9Hi < Hf < 1.4Hi The nanoindentation hardness is measured according to ISO14577-1 at a temperature of 30 °C, The weather resistance test is carried out under the conditions of an illuminance of 50 mW / cm 2 , a blackboard temperature of 63 °C, a relative humidity of 50%, and continuous irradiation for 50 hours.

2. The laminate for post-curing thermoforming according to claim 1, characterized in that, the hard coat contains a polymer having a (meth)acryloyl group and inorganic oxide nanoparticles, when the total of the polymer and the nanoparticles is set to 100 parts by weight, the content of the polymer having a (meth)acryloyl group in the hard coat is 40 to 99 parts by weight, and the content of the inorganic oxide nanoparticles is 1 to 60 parts by weight.

3. The laminate for post-curing thermoforming according to claim 2, characterized in that, the polymer having a (meth)acryloyl group has an acrylic group equivalent of 250 to 700 g / eq, and the inorganic oxide nanoparticles have an average particle size of 5 to 150 nm.

4. The laminate for post-curing thermoforming according to claim 2 or 3, characterized in that, the hard coat further contains a light stabilizer and / or an ultraviolet absorber, when the total of the polymer and the nanoparticles contained in the uncured hard coat is set to 100 parts by weight, the total content of the light stabilizer and / or the ultraviolet absorber is 0.1 to 10 parts by weight.

5. The laminate for post-curing thermoforming according to any one of claims 1 to 4, characterized in that, The nanoindentation hardness of the uncured hard coating at a temperature of 30 °C is 200 N / mm 2 or more.

6. The laminate for post-curing thermoforming according to any one of claims 1 to 5, characterized in that, the hard coat is an active energy ray curable hard coat.

7. The laminate for post-curing thermoforming according to any one of claims 1 to 6, characterized in that, the substrate layer contains a polycarbonate resin.

8. A molded article, characterized in that, the molded article is obtained by curing the uncured hard coat of a molding intermediate obtained by molding the laminate for post-curing thermoforming according to any one of claims 1 to 7.

9. A method for manufacturing a molded article, characterized in that, comprising: a step of thermoforming the laminate for post-curing thermoforming according to any one of claims 1 to 7; a step of removing the protective film from the thermoformed laminate for post-curing thermoforming; and a step of curing the hard coat exposed on the surface by removing the protective film.

10. The method for manufacturing a molded article according to claim 9, characterized in that, the thermoforming is performed by insert molding.

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