Multilayer resin sheet for molding, and molded article using same

Abstract

The present invention is able to provide a multilayer resin sheet for molding, which comprises: a high-hardness resin layer that contains a high-hardness resin; a base material layer that is disposed on one surface side of the high-hardness resin layer and contains a polycarbonate resin (a1); and a hard coating layer that is disposed on the other surface side of the high-hardness resin layer. The hard coating layer has an indentation creep of 7.0% or less and a maximum indentation depth of 890 nm or less in an indentation test, and the hard coating layer is formed of a hard coating composition that contains (A) a 2-15 functional (meth)acrylate oligomer, (B) a 1-2 functional (meth)acrylate monomer that has a molecular weight of less than 200, (C) a photopolymerization initiator, and (D) a surface modification agent. The content of the component (C) is 1.2-1.8 parts by mass relative to a total of 100 parts by mass of the component (A), the component (B), the component (C), and the component (D).

Description

Laminated resin sheet for molding and molded product using same

[0001] The present invention relates to a moldable laminated resin sheet and a molded article using the same.

[0002] Resin molded articles are used for automobile interior parts such as instrument covers, housings for home appliances, office automation equipment, personal computers, and small portable devices, and touch panel display surfaces for mobile phone terminals, etc. Resin molded articles used for such applications are produced by molding a molding resin sheet.

[0003] Polycarbonate (PC) resin has attracted attention as a resin suitable for the above-mentioned applications. PC resin is known as an engineering plastic (engineering plastic) that is excellent in transparency, lightness, and impact resistance, and is suitably used for the above-mentioned applications.

[0004] For example, Patent Document 1 describes an invention relating to a polycarbonate resin laminate with a hard coating layer for hot bending, which is characterized by having a hard coating layer laminated on at least one surface of a polycarbonate resin. The invention described in Patent Document 1 provides a method for producing a curved member that is excellent in abrasion resistance, hot bending property, and adhesion after hot bending.

[0005] However, as described in Patent Document 1, the outermost surface of a polycarbonate resin molded product does not have sufficient pencil hardness, and is therefore prone to scratches when it comes into contact with hard members. This poses a problem in that the product cannot be used for housings of small portable devices or touch panel display surfaces of mobile phone terminals and the like, which require high surface hardness.

[0006] WO2021 / 070632

[0007] Therefore, an object of the present invention is to provide a laminated resin sheet for molding which has high hardness and scratch resistance, is less likely to cause abnormal appearance during molding, and has excellent adhesion, and to provide a molded product using the same.

[0008] As a result of intensive research aimed at solving the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by providing a high-hardness resin layer on a polycarbonate resin layer (substrate layer) and further providing a hard coat layer containing a specific component on the high-hardness resin layer. <1> A moldable laminate resin sheet comprising: a high-hardness resin layer containing a high-hardness resin; a substrate layer containing a polycarbonate resin (a1) disposed on one side of the high-hardness resin layer; and a hard coat layer disposed on the other side of the high-hardness resin layer, wherein the hard coat layer has an indentation creep of 7.0% or less and a maximum indentation depth of 890 nm or less in an indentation test; and the hard coat layer is made of a hard coating composition containing: (A) a di- to di-functional (meth)acrylate oligomer; (B) a mono- or di-functional (meth)acrylate monomer having a molecular weight of less than 200; (C) a photopolymerization initiator; and (D) a surface modifier, and the content of the component (C) is 1.2 to 1.8 parts by mass per 100 parts by mass of the total of the components (A), (B), (C), and (D). <2> The moldable laminate resin sheet according to <1> above, wherein the indentation creep in the indentation test is 5.3 to 7.0% and the maximum indentation depth is 700 to 890 nm. <3> The moldable laminate resin sheet according to <1> above, wherein the content of the component (A) is 40 to 70 parts by mass per 100 parts by mass of the components (A), (B), (C), and (D), the content of the component (B) is 20 to 55 parts by mass per 100 parts by mass of the components (A), (B), (C), and (D), and the content of the component (D) is 0.1 to 10 parts by mass per 100 parts by mass of the components (A), (B), (C), and (D). <4> The moldable laminate resin sheet according to any one of <1> to <3>, wherein the polycarbonate resin (a1) is an aromatic polycarbonate resin. <5> The aromatic polycarbonate resin is a compound represented by the following formula (3a): The moldable laminate resin sheet according to any one of <1> to <4> above, comprising a structural unit represented by the formula: <6> The moldable laminate resin sheet according to any one of <1> to <5> above, wherein the content of the polycarbonate resin (a1) is 75 to 100 mass% relative to the total mass of the base material layer. <7> The moldable laminate resin sheet according to any one of <1> to <6> above, wherein the content of the high-hardness resin is 70 to 100 mass% relative to the total mass of the high-hardness resin layer. <8> The moldable laminate resin sheet according to any one of <1> to <7> above, wherein the total thickness of the base material layer and the high-hardness resin layer is 0.5 to 3.5 mm. <9> The moldable laminate resin sheet according to any one of <1> to <8> above, wherein the proportion of the thickness of the base material layer to the total thickness of the base material layer and the high-hardness resin layer is 75% to 99%. <10> The formable laminate resin sheet according to any one of <1> to <9> above, wherein the hard coat layer has a surface with a pencil hardness of 2H or more. <11> A molded product formed using the formable laminate resin sheet according to any one of <1> to <10> above.

[0009] According to the present invention, there are provided a laminated resin sheet for molding which has high hardness and scratch resistance, is less likely to cause abnormal appearance during molding, and has excellent adhesion, and a resin molded product using the same.

[0010] FIG. 2 is a schematic diagram of an aluminum hot press mold used when hot press molding a moldable laminate resin sheet in the examples.

[0011] Hereinafter, the present invention will be described in detail by way of examples and working examples, but the present invention is not limited to the illustrated examples and working examples, and can be carried out by any method as long as it does not significantly deviate from the content of the present invention.

[0012] The molding laminate resin sheet of the present invention (hereinafter also simply referred to as "resin sheet") includes a high-hardness resin layer containing a high-hardness resin, a substrate layer containing a polycarbonate resin (a1) arranged on one side of the high-hardness resin layer, and a hard coat layer arranged on the other side of the high-hardness resin layer. That is, the substrate layer, the high-hardness resin layer, and the hard coat layer are arranged in this order. Additional layers may be present between the substrate layer and the high-hardness resin layer, and between the high-hardness resin layer and the hard coat layer. Examples of additional layers include, but are not limited to, an adhesive layer and a primer layer. Additional layers may not be present. According to one embodiment, the substrate layer, the high-hardness resin layer, and the hard coat layer are laminated together. That is, according to one embodiment, the molding laminate resin sheet has a high-hardness resin layer containing a high-hardness resin, a base layer containing a polycarbonate resin (a1) laminated on one surface of the high-hardness resin layer, and a hard coat layer laminated on the other surface of the high-hardness resin layer.

[0013] The high-hardness resin layer and the hard coat layer may be provided on at least one side of the substrate layer, and there is no particular limitation on the configuration of the other side. Also, the high-hardness resin layer may be provided on both sides of the substrate layer, and in this case, a hard coat layer can be provided on one or both of the high-hardness resin layers. When the high-hardness resin layer is provided on both sides of the substrate layer, it is desirable to use the same high-hardness resin for the two high-hardness resin layers in order to obtain a stable resin sheet with little warping.

[0014] In the present invention, the indentation creep of the hard coat layer in an indentation test is 7.0% or less, preferably 5.0 to 6.9%, and more preferably 5.3 to 6.8%. This allows for preventing the occurrence of cracks or other external defects during molding while maintaining sufficient hardness. Note that indentation creep refers to the relative change in indentation depth when the indentation depth is measured at a constant test load. Furthermore, the maximum indentation depth of the hard coat layer is 890 nm or less, preferably 650 to 885 nm, and more preferably 700 to 880 nm. This allows for preventing the occurrence of cracks or other external defects during molding while maintaining sufficient hardness. Note that the maximum indentation depth refers to the displacement of the fitted line under the test load. In the present invention, the indentation creep and maximum indentation depth values ​​of the hard coat layer are values ​​measured using a Fischer HM2000 LT, specifically, values ​​measured using the method described in the Examples below.

[0015] The above-mentioned moldable laminate resin sheet can be suitably used to manufacture molded products having a curved shape that requires high hardness. For example, it can be used to successfully manufacture components having a flat portion and a continuous curved portion, thereby providing products with novel designs and functions.

[0016] When conventional resin sheets are used to manufacture molded articles having the above-described shapes, problems such as cracks occurring during thermoforming, such as heat press molding, vacuum molding, pressure molding, and TOM molding, have often occurred. Therefore, in order to suppress the occurrence of cracks during thermoforming, it has been necessary to devise measures such as reducing the hardness of the hard coat. However, reducing the hard coat hardness improves thermoformability, but this leads to new problems, such as the hard coat being soft and therefore prone to scratches, and reduced chemical resistance.

[0017] In contrast, according to the present invention, since the occurrence of cracks is suppressed as described above, it is possible to provide a thermoformable resin sheet without reducing the hardness of the hard coat. The moldable laminate resin sheet of the present invention has a hard hard coat layer on the surface, making it scratch-resistant and highly chemical-resistant. By utilizing these properties, the moldable laminate resin sheet of the present invention can be used for components for display surfaces of personal computers and mobile phones, exterior and interior components of automobiles, and curved housings and front panels for mobile phone terminals, personal computers, tablet PCs, car navigation systems, etc.

[0018] Each of the components of the resin sheet according to the present invention will be described below. <Substrate Layer> The substrate layer contains a polycarbonate resin (a1). The substrate layer may further contain other resins, additives, etc.

[0019] (Polycarbonate Resin (a1)) The polycarbonate resin (a1) is not particularly limited as long as it contains a carbonate bond, i.e., a -[O-R-OCO]- unit (where R may contain an aliphatic group, an aromatic group, or both an aliphatic group and an aromatic group, and may have a linear or branched structure), in the molecular main chain. However, an aromatic polycarbonate resin is preferred, and it is particularly preferred to use a polycarbonate resin containing a structural unit of the following formula (3a):

[0020]

[0021] Specifically, aromatic polycarbonate resins (e.g., Iupilon S-2000, Iupilon S-1000, Iupilon E-2000; manufactured by Mitsubishi Engineering-Plastics Corporation) can be used as the polycarbonate resin (a1). By using such polycarbonate resins, a resin sheet with superior impact resistance can be obtained.

[0022] In recent years, polycarbonate resins to which a monohydric phenol represented by the following general formula (3) has been added as a terminal terminator have been used for the purpose of controlling the glass transition temperature of the polycarbonate resin. In the present invention, polycarbonate resins to which such a terminal terminator has been added can also be used.

[0023]

[0024] In the formula, R ５ represents an alkyl group having 8 to 36 carbon atoms or an alkenyl group having 8 to 36 carbon atoms; R ６ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, or an aryl group having 6 to 12 carbon atoms; and n is an integer from 0 to 4; here, the substituent is a halogen, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 12 carbon atoms. In this specification, the "alkyl group" and the "alkenyl group" may be linear or branched, and may have a substituent.

[0025] The monohydric phenol represented by the general formula (3) is preferably one represented by the following general formula (4).

[0026]

[0027] In the formula, R ５ represents an alkyl group having 8 to 36 carbon atoms or an alkenyl group having 8 to 36 carbon atoms.

[0028] R in general formula (3) or general formula (4) ５ It is more preferable that the number of carbon atoms in R is within a specific numerical range. ５ The upper limit of the number of carbon atoms in R is preferably 36, more preferably 22, and particularly preferably 18. ５ The lower limit of the number of carbon atoms is preferably 8, and more preferably 12.

[0029] R in general formula (3) or general formula (4) ５ When the upper limit of the carbon number is appropriate, the solubility of the monohydric phenol (terminal terminator) in organic solvents tends to be high, which is preferable since it increases the productivity during the production of polycarbonate resins.

[0030] As an example, R ５ When the number of carbon atoms in R is 36 or less, the productivity in producing the polycarbonate resin is high and the economic efficiency is also good. ５ When the carbon number of the monohydric phenol is 22 or less, the monohydric phenol has particularly excellent solubility in organic solvents, and the productivity in producing the polycarbonate resin can be significantly increased, resulting in improved economic efficiency. An example of a polycarbonate resin using such a monohydric phenol is Iupizeta T-1380 (manufactured by Mitsubishi Gas Chemical Company).

[0031] R in general formula (3) or general formula (4) ５ When the lower limit of the number of carbon atoms is appropriate, the glass transition point of the polycarbonate resin is not too high, and the polycarbonate resin has favorable thermoformability, which is preferable.

[0032] For example, in general formula (4), R ５ When a monohydric phenol in which the alkyl group has 16 carbon atoms is used as the end terminator, a polycarbonate resin excellent in glass transition temperature, melt fluidity, moldability, drawdown resistance, etc. can be obtained, and the monohydric phenol also has excellent solubility in solvents during the production of the polycarbonate resin, and this is particularly preferred.

[0033] Among the monohydric phenols represented by general formula (3) or general formula (4), it is particularly preferable to use either or both of parahydroxybenzoic acid hexadecyl ester and parahydroxybenzoic acid 2-hexyldecyl ester as the end terminator.

[0034] The weight-average molecular weight of the polycarbonate resin (a1) is preferably 15,000 to 75,000, more preferably 20,000 to 70,000, and even more preferably 20,000 to 65,000. A weight-average molecular weight of 15,000 or more of the polycarbonate resin (a1) is preferred because it can provide high impact resistance. On the other hand, a weight-average molecular weight of 75,000 or less is preferred because it allows the substrate layer to be formed with a small heat source and maintains thermal stability even under high molding temperatures. In this specification, the weight-average molecular weight is the weight-average molecular weight measured by gel permeation chromatography (GPC) in terms of standard polystyrene.

[0035] The Tg of the polycarbonate resin (a1) is preferably 90 to 190°C, more preferably 100 to 170°C, and even more preferably 110 to 150°C. The Tg of the polycarbonate resin (a1) can be controlled by appropriately adjusting the type and combination of structural units of the polycarbonate resin (a1), the weight-average molecular weight, etc. In this specification, the glass transition point is the temperature calculated by the midpoint method using a differential scanning calorimeter to measure a 10 mg sample at a heating rate of 10°C / min.

[0036] The polycarbonate resin (a1) contained in the substrate layer may be one type or two or more types.

[0037] The content of the polycarbonate resin (a1) in the substrate layer is preferably 75 to 100 mass %, more preferably 90 to 100 mass %, and particularly preferably 100 mass %, based on the total mass of the substrate layer. A polycarbonate resin content of 75 mass % or more is preferred because impact resistance can be further improved.

[0038] (Other Resins) Other resins that may be contained in the base layer are not particularly limited, and examples thereof include polyester resins, etc. The polyester resin preferably contains terephthalic acid as a dicarboxylic acid component, and may contain a dicarboxylic acid component other than terephthalic acid.

[0039] For example, a polyester resin (so-called "PETG") obtained by polycondensation of a glycol component containing 80 to 60 mol % of ethylene glycol as the main component and 20 to 40 mol % of 1,4-cyclohexanedimethanol (total 100 mol %) is preferred. The other resins may be used alone or in combination of two or more.

[0040] When other resins are contained, the content thereof is preferably 0 to 25% by mass, more preferably 0 to 10% by mass, and particularly preferably 0% by mass, relative to the total mass of the substrate layer.

[0041] (Additives) The additives that may be contained in the base layer can be those that are commonly used in resin sheets.Specific examples include antioxidants, anti-coloring agents, anti-static agents, release agents, lubricants, dyes, pigments, plasticizers, flame retardants, resin modifiers, compatibilizers, and reinforcing materials such as organic fillers and inorganic fillers.These additives can be used alone or in combination of two or more.

[0042] The amount of the additive is preferably 0 to 10% by mass, more preferably 0 to 7% by mass, and particularly preferably 0 to 5% by mass, based on the total mass of the substrate layer.

[0043] The method for mixing the additive and the resin is not particularly limited, and methods such as compounding the entire amount, dry blending a master batch, and dry blending the entire amount can be used.

[0044] (Base Layer) The thickness of the base layer is preferably 0.3 to 3.5 mm, more preferably 0.3 to 3.0 mm, and even more preferably 1.0 to 3.0 mm.

[0045] <High-Hardness Resin Layer> The high-hardness resin layer contains a high-hardness resin. It may further contain other resins, additives, etc., as necessary. In this specification, a high-hardness resin refers to a resin that is harder than the polycarbonate resin used as the base material, and has a pencil hardness of HB or higher, preferably HB to 3H, more preferably H to 3H, and even more preferably 2H to 3H. The pencil hardness of the high-hardness resin layer is the result of evaluation using a pencil scratch hardness test in accordance with JIS K 5600-5-4:1999. Specifically, pencils of gradually increasing hardness were pressed against the surface of the high-hardness resin layer at an angle of 45 degrees and a load of 750 g, and the hardness of the hardest pencil that did not produce a scratch was evaluated as the pencil hardness.

[0046] [High-Hardness Resin] The high-hardness resin is not particularly limited, but preferably contains at least one selected from the group consisting of resins (B1) to (B6).

[0047] (Resin (B1)) Resin (B1) is a copolymer containing a (meth)acrylic acid ester structural unit (a) represented by general formula (1) and an aliphatic vinyl structural unit (b) represented by general formula (2). In this case, the resin (B1) may further contain other structural units. In this specification, (meth)acrylic refers to methacrylic and / or acrylic.

[0048]

[0049] In the formula, R １ is a hydrogen atom or a methyl group, preferably a methyl group. ２ is an alkyl group having 1 to 18 carbon atoms, preferably an alkyl group having 1 to 10 carbon atoms, and more preferably an alkyl group having 1 to 6 carbon atoms. Specific examples include a methyl group, an ethyl group, a butyl group, a lauryl group, a stearyl group, a cyclohexyl group, and an isobornyl group. Of these, R ２ is preferably a methyl group or an ethyl group, and more preferably a methyl group.

[0050] In addition, R ２is a methyl group or an ethyl group, the (meth)acrylic acid ester structural unit (a) represented by general formula (1) becomes a (meth)acrylic acid ester structural unit, and R １ is a methyl group and R ２ is a methyl group, the (meth)acrylic acid ester structural unit (a) represented by general formula (1) becomes a methyl methacrylate structural unit.

[0051] The (meth)acrylic acid ester structural unit (a) represented by the general formula (1) may be contained in the resin (B1) either alone or in combination of two or more.

[0052]

[0053] In the formula, R ３ is a hydrogen atom or a methyl group, and is preferably a hydrogen atom. ４ is a cyclohexyl group which may be substituted with a hydrocarbon group having 1 to 4 carbon atoms, and is preferably an unsubstituted cyclohexyl group.

[0054] R ３ is a hydrogen atom, and R ４ is a cyclohexyl group, the aliphatic vinyl structural unit (b) represented by general formula (2) is a vinylcyclohexane structural unit.

[0055] The aliphatic vinyl structural unit (b) represented by general formula (2) may be contained in the resin (B1) either alone or in combination of two or more.

[0056] In this specification, the "hydrocarbon group" may be straight-chain, branched-chain, or cyclic, and may have a substituent.

[0057] The other structural units are not particularly limited, but include structural units derived from aromatic vinyl monomers containing unhydrogenated aromatic double bonds, which are generated in the process of producing resin (B1) by polymerizing a (meth)acrylic acid ester monomer and an aromatic vinyl monomer and then hydrogenating the aromatic double bonds derived from the aromatic vinyl monomer.Specific examples of other structural units include styrene structural units.Resin (B1) may contain only one type of other structural unit, or two or more types.

[0058] The total content of the (meth)acrylic acid ester structural unit (a) and the aliphatic vinyl structural unit (b) is preferably 90 to 100 mol %, more preferably 95 to 100 mol %, and particularly preferably 98 to 100 mol %, based on all structural units of the resin (B1).

[0059] The content of the (meth)acrylic acid ester structural unit (a) represented by general formula (1) is preferably 65 to 80 mol %, more preferably 70 to 80 mol %, based on the total structural units of the resin (B1). A proportion of the (meth)acrylic acid ester structural unit (a) of 65 mol % or more is preferred because it allows for a resin layer having excellent adhesion to the substrate layer and surface hardness. On the other hand, a proportion of the (meth)acrylic acid ester structural unit (a) of 80 mol % or less is preferred because it reduces the risk of warping of the resin sheet due to water absorption.

[0060] The content of the aliphatic vinyl structural unit (b) represented by general formula (2) is preferably 20 to 35 mol %, more preferably 20 to 30 mol %, based on the total structural units of the resin (B1). A content of the aliphatic vinyl structural unit (b) of 20 mol % or more is preferred because warping under high temperature and high humidity conditions can be prevented. On the other hand, a content of the aliphatic vinyl structural unit (b) of 35 mol % or less is preferred because peeling at the interface with the base layer can be prevented.

[0061] Furthermore, the content of other structural units is preferably 10 mol % or less, more preferably 5 mol % or less, and particularly preferably 2 mol % or less, based on all structural units of the resin (B1).

[0062] In this specification, the term "copolymer" may have any of the structures of a random copolymer, a block copolymer, and an alternating copolymer.

[0063] There are no particular restrictions on the weight average molecular weight of the resin (B1), but from the viewpoints of strength and moldability, it is preferably from 50,000 to 400,000, and more preferably from 70,000 to 300,000.

[0064] The glass transition point of resin (B1) is preferably 110 to 140°C, more preferably 110 to 135°C, and particularly preferably 110 to 130°C. A glass transition point of 110°C or higher is preferred because the resin sheet is less likely to deform or crack in a hot or humid heat environment. On the other hand, a glass transition point of 140°C or lower is preferred because it provides excellent processability when molded by continuous thermal shaping using a mirrored roll or a shaping roll, or batch-type thermal shaping using a mirrored mold or a shaping mold.

[0065] Specific examples of the resin (B1) include Optimus 7500 and 6000 (manufactured by Mitsubishi Gas Chemical Company, Ltd.) The above-mentioned resin (B1) may be used alone or in combination of two or more kinds.

[0066] When resin (B1) is used as the high-hardness resin, it is preferable to use Iupizeta T-1380 (manufactured by Mitsubishi Gas Chemical Company) as the polycarbonate resin (a1).

[0067] Furthermore, as the high-hardness resin, a structural unit represented by general formula (1) (R １ , R ２ methyl methacrylate) at 75 mol %, and a structural unit represented by general formula (2) (R ３ is a hydrogen atom, R ４ The resin (B1) is a copolymer containing 25 mol % of a cyclohexyl group; vinylcyclohexane), and the polycarbonate resin (a1) is a polycarbonate resin containing a structural unit of formula (3a), and the polycarbonate resin (a2) is a monohydric phenol (R ５ It is particularly preferred to use an alkyl group having 8 to 22 carbon atoms.

[0068] The method for producing the resin (B1) is not particularly limited, but a resin obtained by polymerizing at least one (meth)acrylic acid ester monomer and at least one aromatic vinyl monomer, and then hydrogenating the aromatic double bond derived from the aromatic vinyl monomer, is suitable.

[0069] The aromatic vinyl monomer is not particularly limited, but examples thereof include styrene, α-methylstyrene, p-hydroxystyrene, alkoxystyrene, chlorostyrene, and derivatives thereof. Among these, the aromatic vinyl monomer is preferably styrene.

[0070] Known methods can be used for polymerizing the (meth)acrylic acid ester monomer and the aromatic vinyl monomer, and the polymer can be produced by, for example, bulk polymerization or solution polymerization. Bulk polymerization is carried out by continuously supplying a monomer composition containing the above-mentioned monomers and a polymerization initiator to a complete mixing tank and continuously polymerizing the monomers at 100 to 180°C. The monomer composition may contain a chain transfer agent as needed.

[0071] The polymerization initiator is not particularly limited, but examples thereof include organic peroxides such as t-amylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, benzoyl peroxide, 1,1-di(t-hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(t-hexylperoxy)cyclohexane, 1,1-di(t-butylperoxy)cyclohexane, t-hexylpropoxyisopropyl monocarbonate, t-amylperoxy-normal-octoate, t-butylperoxyisopropyl monocarbonate, and di-t-butyl peroxide, and azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), and 2,2'-azobis(2,4-dimethylvaleronitrile). These may be used alone or in combination of two or more.

[0072] The chain transfer agent is not particularly limited, but examples thereof include α-methylstyrene dimer.

[0073] Examples of solvents used in solution polymerization include hydrocarbon solvents such as toluene, xylene, cyclohexane, and methylcyclohexane; ester solvents such as ethyl acetate and methyl isobutyrate; ketone solvents such as acetone and methyl ethyl ketone; ether solvents such as tetrahydrofuran and dioxane; and alcohol solvents such as methanol and isopropanol. These solvents may be used alone or in combination of two or more.

[0074] The solvent used in the hydrogenation reaction for hydrogenating the aromatic double bonds derived from the aromatic vinyl monomer after polymerizing the (meth)acrylic acid ester monomer and the aromatic vinyl monomer may be the same as or different from the above-mentioned polymerization solvent. Examples thereof include hydrocarbon solvents such as cyclohexane and methylcyclohexane, ester solvents such as ethyl acetate and methyl isobutyrate, ketone solvents such as acetone and methyl ethyl ketone, ether solvents such as tetrahydrofuran and dioxane, and alcohol solvents such as methanol and isopropanol.

[0075] The hydrogenation method is not particularly limited, and known methods can be used. For example, the hydrogenation can be carried out in a batch or continuous flow system at a hydrogen pressure of 3 to 30 MPa and a reaction temperature of 60 to 250°C. A reaction temperature of 60°C or higher is preferred because the reaction time is not too long. On the other hand, a reaction temperature of 250°C or lower is preferred because side reactions such as scission of molecular chains and hydrogenation of ester moieties do not occur or occur very little.

[0076] Examples of catalysts used in the hydrogenation reaction include solid catalysts in which a metal such as nickel, palladium, platinum, cobalt, ruthenium, or rhodium, or an oxide, salt, or complex compound of such a metal, is supported on a porous carrier such as carbon, alumina, silica, silica-alumina, or diatomaceous earth.

[0077] It is preferable that 70% or more of the aromatic double bonds derived from the aromatic vinyl monomer are hydrogenated by the hydrogenation reaction. That is, the unhydrogenated ratio of the aromatic double bonds contained in the structural units derived from the aromatic vinyl monomer is preferably less than 30%, more preferably less than 10%, and even more preferably less than 5%. When the unhydrogenated ratio is less than 30%, it is possible to obtain a resin with excellent transparency, which is preferable. The structural units of the unhydrogenated portion can be other structural units in the resin (B1).

[0078] (Resin (B2)) Resin (B2) is a copolymer containing 6 to 77 mass% of (meth)acrylic acid ester structural units, 15 to 71 mass% of styrene structural units, and 8 to 23 mass% of unsaturated dicarboxylic acid structural units. In this case, the resin (B2) may further contain other structural units.

[0079] The (meth)acrylic acid ester monomer constituting the (meth)acrylic acid ester structural unit in the resin (B2) is not particularly limited, but examples thereof include acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, and 2-ethylhexyl methacrylate. Of these, the (meth)acrylic acid ester monomer is preferably methyl methacrylate. The above-mentioned (meth)acrylic acid ester monomers may be contained alone or in combination of two or more as the (meth)acrylic acid ester structural unit.

[0080] The content of the (meth)acrylic acid ester structural unit is from 6 to 77% by mass, and preferably from 20 to 70% by mass, based on the total mass of the resin (B2).

[0081] The styrene structural unit in the resin (B2) is not particularly limited, and any known styrene-based monomer can be used. Examples of the styrene-based monomer include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, and t-butylstyrene, from the viewpoint of availability. Among these, styrene is preferred as the styrene-based monomer from the viewpoint of compatibility. The above-mentioned styrene-based monomers may be contained alone as the styrene structural unit, or two or more types may be contained in combination.

[0082] The content of styrene structural units is from 15 to 71% by mass, and preferably from 20 to 66% by mass, based on the total mass of the resin (B2).

[0083] The unsaturated dicarboxylic acid anhydride monomer constituting the unsaturated dicarboxylic acid structural unit in the resin (B2) is not particularly limited, and examples thereof include acid anhydrides such as maleic acid, itaconic acid, citraconic acid, and aconitic acid. Among these, from the viewpoint of compatibility with styrene-based monomers, the unsaturated dicarboxylic acid anhydride monomer is preferably maleic acid anhydride. The unsaturated dicarboxylic acid anhydride monomers described above may be contained alone or in combination of two or more as the unsaturated dicarboxylic acid structural unit.

[0084] The content of the unsaturated dicarboxylic acid structural unit is from 8 to 23% by mass, and preferably from 10 to 23% by mass, based on the total mass of the resin (B2).

[0085] Examples of other structural units in the resin (B2) include N-phenylmaleimide.

[0086] The content of other structural units is preferably 10 mol % or less, more preferably 5 mol % or less, and particularly preferably 2 mol % or less, based on all structural units of the resin (B2).

[0087] The total content of the (meth)acrylic acid ester structural units, styrene structural units, and unsaturated dicarboxylic acid structural units is preferably 90 to 100 mol %, more preferably 95 to 100 mol %, and particularly preferably 98 to 100 mol %, based on all structural units of the resin (B2).

[0088] The weight average molecular weight of the resin (B2) is not particularly limited, but is preferably from 50,000 to 300,000, and more preferably from 80,000 to 200,000.

[0089] The glass transition point of the resin (B2) is preferably from 90 to 150°C, more preferably from 100 to 150°C, and particularly preferably from 115 to 150°C.

[0090] Specific examples of the resin (B2) include Resistify R100, R200, and R310 (manufactured by Denka), Delpet 980N (manufactured by Asahi Kasei), and hw55 (manufactured by Daicel-Evonik). The above-mentioned resin (B2) may be used alone or in combination of two or more.

[0091] When resin (B2) is used as the high-hardness resin, a preferred embodiment is to use a polycarbonate resin containing a structural unit of formula (3a) as polycarbonate resin (a1). Furthermore, a monohydric phenol (R ５ It is particularly preferred to use a polycarbonate resin having a carbon number of 8 to 22. Examples of such polycarbonate resins include Iupizeta T-1380 (manufactured by Mitsubishi Gas Chemical Company), Iupilon E-2000 (manufactured by Mitsubishi Engineering Plastics Corporation), and the like.

[0092] Furthermore, when a copolymer (R100 or R200; manufactured by Denka) resin (B2) composed of 6 to 26 mass% of methyl methacrylate structural units, 55 to 21 mass% of styrene structural units, and 15 to 23 mass% of maleic anhydride structural units is used as the high-hardness resin, a preferred embodiment is to use Iupizeta T-1380 as the polycarbonate resin (a1).

[0093] Furthermore, when resin (B2) is used as the high-hardness resin, which is a copolymer (R310; manufactured by Denka) composed of 6 mass% of methyl methacrylate structural units, 71 mass% of styrene structural units, and 23 mass% of maleic anhydride structural units, a particularly preferred embodiment is one in which Iupizeta T-1380 is used as the polycarbonate resin (a1).

[0094] The method for producing the resin (B2) is not particularly limited, but examples thereof include bulk polymerization and solution polymerization.

[0095] (Resin (B3)) Resin (B3) is a polymer containing a structural unit (c) represented by formula (5). In this case, it is preferable that the polymer further contains a structural unit (d) represented by formula (6). Furthermore, the polymer may further contain other structural units.

[0096]

[0097] The content of the structural unit (c) represented by formula (5) is preferably 50 to 100 mol %, more preferably 60 to 100 mol %, and particularly preferably 70 to 100 mol %, based on all structural units of the resin (B3).

[0098]

[0099] The content of the structural unit (d) represented by formula (6) is preferably 0 to 50 mol %, more preferably 0 to 40 mol %, and particularly preferably 0 to 30 mol %, based on all structural units of the resin (B3).

[0100] The content of other structural units is preferably 10 mol % or less, more preferably 5 mol % or less, and particularly preferably 2 mol % or less, based on all structural units of the resin (B3).

[0101] The total content of the structural units (c) and (d) relative to all structural units in the resin (B3) is preferably 90 to 100 mol %, more preferably 95 to 100 mol %, and even more preferably 98 to 100 mol %.

[0102] The weight average molecular weight of the resin (B3) is preferably from 15,000 to 75,000, more preferably from 20,000 to 70,000, and particularly preferably from 25,000 to 65,000.

[0103] The glass transition point of the resin (B3) is preferably from 105 to 150°C, more preferably from 110 to 140°C, and particularly preferably from 110 to 135°C.

[0104] Specific examples of the resin (B3) include Iupilon KH3410UR, KH3520UR, and KS3410UR (manufactured by Mitsubishi Engineering-Plastics Corporation). The resin (B3) may be used alone or in combination of two or more.

[0105] When resin (B3) is used as the high-hardness resin, a preferred embodiment is to use a polycarbonate resin containing a structural unit of formula (3a) as polycarbonate resin (a1). Furthermore, a monohydric phenol (R ５ A particularly preferred embodiment uses a polycarbonate resin (a1) having 8 to 22 carbon atoms. An example of such a polycarbonate resin is Iupizeta T-1380 (manufactured by Mitsubishi Gas Chemical Company). It is particularly preferred to use Iupilon KS3410UR (manufactured by Mitsubishi Engineering Plastics Corporation) as the resin (B3) and Iupizeta T-1380 (manufactured by Mitsubishi Gas Chemical Company) as the polycarbonate resin (a1).

[0106] When resin (B3) is used as the high-hardness resin, it is preferable that it contains a resin other than resins (B1) to (B6). In this case, the resin other than resins (B1) to (B6) is preferably a resin that does not contain structural unit (c) but contains structural unit (d), and more preferably a resin consisting only of structural unit (d). Specifically, aromatic polycarbonate resins (e.g., Iupilon S-2000, Iupilon S-1000, Iupilon E-2000; manufactured by Mitsubishi Engineering-Plastics Corporation) can be used.

[0107] When a resin other than the resins (B1) to (B6) is contained, the resin (B3) is contained in an amount of preferably 45% by mass or more, more preferably 55% by mass or more, based on the total resins contained in the high-hardness resin layer.

[0108] The method for producing resin (B3) is not particularly limited, but it can be produced by the same method as the method for producing polycarbonate resin (a1) described above, except that bisphenol C is used as the monomer.

[0109] (Resin (B4)) Resin (B4) is a copolymer containing 5 to 20 mass% of styrene structural units, 60 to 90 mass% of (meth)acrylic acid ester structural units, and 5 to 20 mass% of N-substituted maleimide structural units. Note that resin (B4) may further contain other structural units.

[0110] The styrene structural unit in the resin (B4) is not particularly limited, and any known styrene-based monomer can be used. Examples of the styrene-based monomer include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, and t-butylstyrene, from the viewpoint of availability. Among these, styrene is preferred as the styrene-based monomer from the viewpoint of compatibility. The above-mentioned styrene-based monomers may be contained alone as the styrene structural unit, or two or more types may be contained in combination.

[0111] The content of styrene structural units is from 5 to 20% by mass, preferably from 5 to 15% by mass, and more preferably from 5 to 10% by mass, based on the total mass of the resin (B4).

[0112] The (meth)acrylic acid ester monomer constituting the (meth)acrylic acid ester structural unit in the resin (B4) is not particularly limited, but examples thereof include acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, and 2-ethylhexyl methacrylate. Of these, the (meth)acrylic acid ester monomer is preferably methyl methacrylate. The above-mentioned (meth)acrylic acid ester monomers may be contained alone or in combination of two or more as the (meth)acrylic acid ester structural unit.

[0113] The content of the (meth)acrylic acid ester structural unit is 60 to 90 mass %, preferably 70 to 90 mass %, and more preferably 80 to 90 mass %, based on the total mass of the resin (B4).

[0114] Examples of the N-substituted maleimide structural unit in the resin (B4) include structural units derived from N-arylmaleimides such as N-phenylmaleimide, N-chlorophenylmaleimide, N-methylphenylmaleimide, N-naphthylmaleimide, N-hydroxyphenylmaleimide, N-methoxyphenylmaleimide, N-carboxyphenylmaleimide, N-nitrophenylmaleimide, and N-tribromophenylmaleimide. Of these, structural units derived from N-phenylmaleimide are preferred from the viewpoint of compatibility with acrylic resins. The structural units derived from the above-mentioned N-substituted maleimides may be contained alone as N-substituted maleimide structural units, or two or more types may be contained in combination.

[0115] The content of the N-substituted maleimide structural units is from 5 to 20% by mass, preferably from 5 to 15% by mass, and more preferably from 5 to 10% by mass, relative to the total mass of the resin (B4).

[0116] Examples of the other structural units include a (meth)acrylic acid ester structural unit represented by general formula (1) and an aliphatic vinyl structural unit represented by general formula (2), where general formula (1) and general formula (2) are the same as those of the resin (B1) described above.

[0117] The content of other structural units is preferably 10 mol % or less, more preferably 5 mol % or less, and particularly preferably 2 mol % or less, based on all structural units of the resin (B4).

[0118] The total content of the styrene structural units, (meth)acrylic acid ester structural units, and N-substituted maleimide structural units is preferably 90 to 100 mol %, more preferably 95 to 100 mol %, and even more preferably 98 to 100 mol %, based on all structural units of the resin (B4).

[0119] The weight average molecular weight of the resin (B4) is preferably 50,000 to 250,000, and more preferably 100,000 to 200,000.

[0120] The glass transition point of the resin (B4) is preferably from 110 to 150°C, more preferably from 120 to 150°C, and particularly preferably from 130 to 150°C.

[0121] A specific example of resin (B4) is Delpet PM120N (manufactured by Asahi Kasei Corporation). Furthermore, it is preferable to use Polyimilex PML203 (manufactured by Nippon Shokubai), which is composed of 9% by mass of styrene structural units, 78% by mass of (meth)acrylic acid ester structural units, and 13% by mass of N-substituted maleimide structural units. The above-mentioned resins (B4) may be used alone or in combination of two or more.

[0122] When resin (B4) is used as the high-hardness resin, a preferred embodiment is to use a polycarbonate resin containing a structural unit of formula (3a) as polycarbonate resin (a1). Furthermore, a monohydric phenol (R ５A particularly preferred embodiment uses a polycarbonate resin having 8 to 22 carbon atoms. An example of such a polycarbonate resin is Iupizeta T-1380 (manufactured by Mitsubishi Gas Chemical Company). It is particularly preferred to use Delpet PM-120N, which is composed of 7% by mass of styrene structural units, 86% by mass of (meth)acrylic acid ester structural units, and 7% by mass of N-substituted maleimide structural units, as resin (B4), and Iupizeta T-1380 as polycarbonate resin (a1).

[0123] The method for producing the resin (B4) is not particularly limited, but it can be produced by solution polymerization, bulk polymerization, or the like.

[0124] (Resin (B5)) The resin (B5) is a polymer containing the structural unit (e) represented by formula (7). In this case, the resin (B5) may further contain other structural units.

[0125]

[0126] The content of the structural unit (e) represented by formula (7) is preferably 80 to 100 mol %, more preferably 90 to 100 mol %, and particularly preferably 95 to 100 mol %, based on all structural units of the resin (B5).

[0127] Examples of other structural units include a structural unit represented by formula (5) and a structural unit represented by formula (6), where formula (5) and formula (6) are the same as those in the resin (B3) described above.

[0128] The content of other structural units is preferably 20 mol % or less, more preferably 10 mol % or less, and particularly preferably 5 mol % or less, based on all structural units of the resin (B5).

[0129] The weight average molecular weight of the resin (B5) is preferably 10,000 to 1,000,000, and more preferably 15,000 to 50,000.

[0130] The glass transition point of the resin (B5) is preferably from 120 to 200°C, more preferably from 130 to 190°C, and particularly preferably from 140 to 190°C.

[0131] A specific example of the resin (B5) is Iupizeta FPC0220 (manufactured by Mitsubishi Gas Chemical Company, Inc.) The above-mentioned resin (B5) may be used alone or in combination of two or more kinds.

[0132] When resin (B5) is used as the high-hardness resin, a preferred embodiment uses a polycarbonate resin containing a structural unit of formula (3a) as polycarbonate resin (a1). An example of such a polycarbonate resin is Iupilon E-2000 (manufactured by Mitsubishi Engineering-Plastics Corporation). It is particularly preferred to use Iupizeta FPC0220 (manufactured by Mitsubishi Gas Chemical Company) as resin (B5) and Iupilon E-2000 (manufactured by Mitsubishi Engineering-Plastics Corporation) as polycarbonate resin (a1).

[0133] When resin (B5) is used as the high-hardness resin, it is preferable that another resin other than resins (B1) to (B6) is contained. In this case, the other resin other than resins (B1) to (B6) is preferably a resin that does not contain structural unit (c) but contains structural unit (d), and more preferably a resin consisting of structural unit (d). Specifically, aromatic polycarbonate resins (e.g., Iupilon S-2000, Iupilon S-1000, Iupilon E-2000; manufactured by Mitsubishi Engineering-Plastics Corporation) can be used.

[0134] When a resin other than the resins (B1) to (B6) is contained, the resin (B5) is contained in an amount of preferably 45% by mass or more, more preferably 55% by mass or more, based on the total resins contained in the high-hardness resin layer.

[0135] The method for producing resin (B5) is not particularly limited, but it can be produced by the same method as the method for producing polycarbonate resin (a1) described above, except that bisphenol AP is used as the monomer.

[0136] (Resin (B6)) Resin (B6) is a copolymer containing 50 to 95% by mass of styrene structural units and 5 to 50% by mass of unsaturated dicarboxylic acid structural units.

[0137] The styrene structural unit may be the styrene-based monomer described in the resin (B4). The resin (B6) may use these styrene structural units alone or in combination of two or more.

[0138] The content of styrene structural units is preferably from 50 to 95 mass %, more preferably from 60 to 90 mass %, and even more preferably from 65 to 87 mass %, based on the total mass of resin (B6).

[0139] Examples of the unsaturated dicarboxylic acid anhydride monomer constituting the unsaturated dicarboxylic acid structural unit include acid anhydrides such as maleic acid, itaconic acid, citraconic acid, and aconitic acid. Among these, maleic anhydride is preferred from the viewpoint of compatibility with styrene-based monomers. The above-mentioned unsaturated dicarboxylic acid anhydride monomers may be used alone or in combination of two or more.

[0140] The content of the unsaturated dicarboxylic acid structural unit is preferably 5 to 50 mass %, more preferably 10 to 40 mass %, and even more preferably 13 to 35 mass %, relative to the total mass of the resin (B6).

[0141] Resin (B6) may contain structural units other than the above-mentioned structural units. Examples of the structural units include a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2).

[0142] In the formula, R １ and R ２ is the same as above.

[0143] In the formula, R ３ and R ４ is the same as above.

[0144] The content of other structural units is preferably 10 mol % or less, more preferably 5 mol % or less, and even more preferably 2 mol % or less, based on all structural units of the resin (B6).

[0145] The weight average molecular weight of the resin (B6) is preferably 50,000 to 250,000, and more preferably 50,000 to 100,000.

[0146] The glass transition point of the resin (B6) is preferably from 110 to 150°C, more preferably from 120 to 150°C, and particularly preferably from 130 to 150°C.

[0147] Specific examples of the resin (B6) include XIBOND 140 and XIBOND 160 (manufactured by Polyscope Co., Ltd.) The above-mentioned resin (B6) may be used alone or in combination of two or more kinds.

[0148] When resin (B6) is used as the high-hardness resin, a preferred embodiment is to use a polycarbonate resin containing a structural unit of formula (3a) as polycarbonate resin (a1). Furthermore, a monohydric phenol (R ５ A particularly preferred embodiment uses a polycarbonate resin having 8 to 22 carbon atoms. An example of such a polycarbonate resin is Iupizeta T-1380 (manufactured by Mitsubishi Gas Chemical Company). It is particularly preferred to use an alloy of XIBOND160, which is composed of 78% by mass of styrene structural units and 22% by mass of maleic anhydride structural units, and an acrylic resin as resin (B6), and to use Iupizeta T-1380 as polycarbonate resin (a1).

[0149] The method for producing the resin (B6) is not particularly limited, but it can be produced by solution polymerization, bulk polymerization, or the like.

[0150] At least one selected from the group consisting of the above-mentioned resins (B1) to (B6) may be contained as an alloy.

[0151] The alloy is not particularly limited, and examples thereof include an alloy of two types of resins (B1), an alloy of two types of resins (B2), an alloy of two types of resins (B3), an alloy of two types of resins (B4), an alloy of two types of resins (B5), an alloy of two types of resins (B6), an alloy of resin (B1) and resin (B2), an alloy of resin (B2) and resin (B4), an alloy of resin (B2) and other high-hardness resins, an alloy of resin (B2) and acrylic resin, and an alloy of resin (B6) and acrylic resin.

[0152] Examples of the other high hardness resins include methyl methacrylate-styrene copolymers and acrylonitrile-butadiene-styrene copolymers.

[0153] Examples of the acrylic resin include polymethyl methacrylate, copolymers of methyl methacrylate and methyl acrylate or ethyl acrylate, etc. Commercially available products include ACRYPET (manufactured by Mitsubishi Chemical Corporation), SUMIPEX (manufactured by Sumitomo Chemical Co., Ltd.), and PARAPET (manufactured by Kuraray Co., Ltd.).

[0154] When two types of resins are alloyed, it is preferable to use an alloy of resins having a higher glass transition temperature. The above-mentioned alloys may be used alone or in combination of two or more types.

[0155] The method for producing the alloy is not particularly limited, but examples include a method in which the alloy is melt-kneaded at a cylinder temperature of 240°C using a twin-screw extruder with a screw diameter of 26 mm, extruded into a strand shape, and pelletized with a pelletizer.

[0156] The high-hardness resin layer may contain one type of high-hardness resin or two or more types of high-hardness resins. When two or more types of high-hardness resins are selected from the resins (B1) to (B6), they may be selected from the same or different categories, and may further contain a high-hardness resin other than the resins (B1) to (B6).

[0157] The content of the high-hardness resin in the high-hardness resin layer is preferably 70 to 100% by mass, more preferably 80 to 100% by mass, and particularly preferably 100% by mass, based on the total mass of the high-hardness resin layer.

[0158] [Other Resins] The high-hardness resin layer may contain other resins in addition to the high-hardness resin. Examples of the other resins include methyl methacrylate-styrene copolymers, polymethyl methacrylate, polystyrene, polycarbonate, cycloolefin (co)polymer resins, acrylonitrile-styrene copolymers, acrylonitrile-butadiene-styrene copolymers, and various elastomers. These other resins may be used alone or in combination of two or more.

[0159] The content of the other resin is preferably 30% by mass or less, more preferably 20% by mass or less, and particularly preferably 0% by mass, based on the total mass of the high-hardness resin layer.

[0160] [Additives] The high-hardness resin layer may contain additives, etc. As the additives, those described above can be used.

[0161] [High-Hardness Resin Layer] The thickness of the high-hardness resin layer is preferably 10 to 250 μm, more preferably 30 to 200 μm, and particularly preferably 60 to 150 μm. A thickness of 10 μm or more is preferred because the surface hardness is increased. On the other hand, a thickness of 250 μm or less is preferred because the impact resistance is increased.

[0162] [Lamination of high-hardness resin layer onto base layer] As described above, an additional layer may be present between the base layer and the high-hardness resin layer, but here, a case where a high-hardness resin layer is laminated on the base layer will be described.

[0163] The method for laminating the high-hardness resin layer on the base layer is not particularly limited, and examples thereof include a method of overlapping a separately formed base layer and a high-hardness resin layer and heat-pressing them together; a method of overlapping a separately formed base layer and a high-hardness resin layer and adhering them together with an adhesive; a method of co-extrusion molding the base layer and the high-hardness resin layer; a method of in-mold molding the base layer into a pre-formed high-hardness resin layer to integrate them, etc. Among these, the co-extrusion molding method is preferred from the viewpoints of production cost and productivity.

[0164] The co-extrusion method is not particularly limited. For example, in the feed block method, a high-hardness resin layer is placed on one side of a substrate layer in a feed block, extruded into a sheet using a T-die, and then cooled while passing through a forming roll to form a desired laminate. In the multi-manifold method, a high-hardness resin layer is placed on one side of a substrate layer in a multi-manifold die, extruded into a sheet, and then cooled while passing through a forming roll to form a desired laminate. The above method can also be used in the same way when laminating a high-hardness resin layer on a layer other than the substrate layer.

[0165] The total thickness of the base layer and the high-hardness resin layer is preferably 0.5 to 3.5 mm, more preferably 0.5 to 3.0 mm, and even more preferably 1.2 to 3.0 mm. A total thickness of 0.5 mm or more is preferable because it allows the rigidity of the sheet to be maintained. On the other hand, a total thickness of 3.5 mm or less is preferable because it prevents the sensitivity of the touch sensor from being reduced when a touch panel is installed under the sheet.

[0166] The ratio of the thickness of the base layer to the total thickness of the base layer and the high-hardness resin layer is preferably 75% to 99%, more preferably 80% to 99%, and particularly preferably 85% to 99%. By setting the ratio within this range, both hardness and impact resistance can be achieved.

[0167] <Hard Coat Layer> In this specification, the term "hard coat" refers to a coating film in which a crosslinked structure is formed by polymerizing a hard coating composition containing a monomer, oligomer, or prepolymer containing a (meth)acryloyl group as a polymerizable group.

[0168] In the present invention, the hard coating composition contains (A) a di- to penta-functional (meth)acrylate oligomer, (B) a mono- or di-functional (meth)acrylate monomer having a molecular weight of less than 200, (C) a photopolymerization initiator, and (D) a surface modifier. In this specification, the photopolymerization initiator refers to a photoradical generator.

[0169] The content of the (meth)acrylate oligomer as component (A) is preferably 40 to 70 parts by mass, more preferably 48 to 67 parts by mass, and particularly preferably 56 to 63 parts by mass, per 100 parts by mass of the total of the components (A), (B), (C), and (D).

[0170] The content of the (meth)acrylate monomer as component (B) is preferably 20 to 55 parts by mass, more preferably 28 to 50 parts by mass, and particularly preferably 36 to 45 parts by mass, per 100 parts by mass of the total of components (A), (B), (C), and (D).

[0171] The content of the photopolymerization initiator, component (C), is 1.2 to 1.8 parts by mass, preferably 1.25 to 1.7 parts by mass, and more preferably 1.3 to 1.6 parts by mass, per 100 parts by mass of the total of components (A), (B), (C), and (D). If the content of component (C) is less than 1.2 parts by mass, this will cause poor curing of the hard coat, while if it exceeds 1.8 parts by mass, it will cause cracks to form on the surface of the hard coat during molding.

[0172] The content of the surface modifier as component (D) is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 8 parts by mass, and even more preferably 1 to 5 parts by mass, per 100 parts by mass of the total of components (A), (B), (C), and (D).

[0173] The viscosity of the hard coating composition containing components (A) to (D) at 25°C is preferably 400 cps or less, more preferably 300 cps or less, and most preferably 150 cps or less. The lower limit is usually about 10 cps. If the viscosity of the hard coating composition at 25°C exceeds 400 cps, the coating film becomes thick during application, making it more susceptible to cracking after thermoforming and significantly reducing processability during cutting. If the viscosity of the hard coating composition at 25°C is below 10 cps, the film thickness during hard coating production may become thin, leading to a decrease in pencil hardness. The viscosity of the hard coating composition can be measured at 25°C using a Sekonic VM-100A-L vibration viscometer.

[0174] <Component (A)> [(Meth)acrylate Oligomer] The (meth)acrylate oligomer used as component (A) in the present invention is a polyfunctional (meth)acrylate oligomer having 2 to 15 functionalities, preferably 2 to 9 functionalities, and more preferably 2 to 6 functionalities. The oligomer referred to here is a polymer having preferably 2 or more structural units, more preferably about 2 to 20 structural units, and has a lower molecular weight limit of about 400 or more, more preferably 1200 or more. The upper molecular weight limit of the oligomer is preferably 6000 or less, more preferably 4000 or less.

[0175] Specific examples of component (A) include the following polyfunctional (meth)acrylate oligomers (1) to (4): (1) polyfunctional polyol (meth)acrylate oligomer, i.e., a polyacrylate or polymethacrylate oligomer obtained by reacting a polyhydric alcohol (polyol or polyhydroxy-containing compound) with a compound selected from the group consisting of acrylic acid, methacrylic acid, and their derivatives; (2) polyfunctional polyester (meth)acrylate oligomer, i.e., a saturated or unsaturated polyester polyacrylate or polymethacrylate oligomer obtained from a polyhydric alcohol (polyol), a polycarboxylic acid (polybasic acid or polybasic carboxylic acid) or its anhydride, and acrylic acid, methacrylic acid, or their derivatives; and (3) polyfunctional urethane (meth)acrylate oligomer, i.e., a urethane polyacrylate or urethane polymethacrylate oligomer obtained from a polyisocyanate and a compound having an active hydrogen and an acryloyloxy group or a methacryloyloxy group. (4) Polyfunctional polyglycidyl ether (meth)acrylate oligomers, i.e., oligomers of polyacrylates or polymethacrylates obtained from polyglycidyl ethers and acrylic acid, methacrylic acid, or derivatives thereof.

[0176] Examples of the polyhydric alcohol (polyol) used in the production of the (1) polyfunctional polyol (meth)acrylate oligomer include dihydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycols having a number average molecular weight of 300 to 1000, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, 2,2'-thiodiethanol, and 1,4-cyclohexanedimethanol; trihydric alcohols such as trimethylolethane, trimethylolpropane, pentaglycerol, glycerol, 1,2,4-butanetriol, and 1,2,6-hexanetriol; and tetrahydric or higher alcohols such as pentaerythritol, diglycerol, and dipentaerythritol.

[0177] The above-mentioned (2) polyfunctional polyester (meth)acrylate oligomer can be obtained by reacting (meth)acrylic acid, a polybasic carboxylic acid (anhydride), and a polyol (a polyhydroxy-containing compound or a polyhydric alcohol). More specifically, a polyester polyol is produced by a dehydration condensation reaction between a dibasic carboxylic acid (anhydride) and a polyol, and then the reaction product is reacted with acrylic acid or methacrylic acid to obtain a polyfunctional polyester (meth)acrylate oligomer.

[0178] The polyhydroxy-containing compounds, also referred to as "polyols," used in the preparation of polyester polyols are preferably compounds having three or more hydroxy groups. Generally, polyols that can be used in the present invention are compounds having three to six hydroxy groups, preferably three to four hydroxy groups, and two to about 36 carbon atoms. Such polyols include branched or straight-chain aliphatic polyols, cycloaliphatic polyols, aromatic polyols, and polyether polyols. Aliphatic polyols can include triols such as glycerin, trimethylolpropane, and trimethylolethane; tetraols such as pentaerythritol and di-trimethylolpropane; and hexaols such as dipentaerythritol. Additionally, aliphatic and cycloaliphatic polyols can be reacted with various amounts of ethylene oxide and / or propylene oxide to produce ethoxylated and / or propoxylated polyols. Examples of ethoxylated and / or propoxylated polyols include ethoxylated trimethylolpropane, propoxylated trimethylolpropane, ethoxylated glycerin, propoxylated glycerin, ethoxylated pentaerythritol, and propoxylated pentaerythritol.

[0179] Examples of aromatic polyols include bisphenol A diacrylate. The polyether polyols that can be used in the present invention include both aromatic polyethers and aliphatic polyethers. The aliphatic groups of the polyether polyols may be linear, branched, or cyclic. Examples of polyether polyols include triglycerides such as triethylene glycol, polyethylene glycol, polypropylene glycol, and polybutylene glycol, as well as mixed polyethers such as poly(propylene-ethylene) glycol.

[0180] Examples of dibasic carboxylic acids (anhydrides) used in the production of polyester polyols include aliphatic dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, and sebacic acid; alicyclic dicarboxylic acids such as tetrahydrophthalic acid and 3,6-endomethylenetetrahydrophthalic acid; aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, and terephthalic acid; and unsaturated dicarboxylic acids such as trimellitic acid, pyromellitic acid, thiodiglycolic acid, thiodivaleric acid, diglycolic acid, and maleic acid, fumaric acid, and itaconic acid. Their chlorides, anhydrides, or esters can also be used. Anhydrides of these dibasic carboxylic acids are preferred. Alicyclic dicarboxylic acid anhydrides such as tetrahydrophthalic anhydride are particularly preferred. Polyester polyols are polyols having ester bonds. For example, an excess of polyol can be reacted with a dibasic acid (anhydride) to obtain a low-molecular-weight compound having about one to about six ester bonds and reactive hydroxy groups. The above polyols can be produced using either a single polyol or a mixture thereof. The polyester polyols may also be further reacted with various amounts of ethylene oxide and / or propylene oxide to provide ethoxylated and / or propoxylated polyester polyols.

[0181] The (2) polyfunctional polyester (meth)acrylate oligomer used in the present invention can be obtained by reacting the polyester polyol obtained in this manner with a compound selected from the group consisting of acrylic acid, methacrylic acid, and derivatives thereof. Among the compounds selected from the group consisting of acrylic acid, methacrylic acid, and derivatives thereof, acrylic acid is more preferably used.

[0182] In the above (2) multifunctional polyester (meth)acrylate oligomer, the polyol (polyhydroxy-containing compound) can be used alone or in combination with other polyhydroxy-containing compounds. Furthermore, compounds selected from the group consisting of acrylic acid, methacrylic acid, and their derivatives can be used alone or in combination with each other. When a mixture of polyhydroxy-containing compounds is used, a mixed ester product is obtained. Similarly, when a mixture of acrylic acid and methacrylic acid is used, the product is a mixed acrylate oligomer.

[0183] A preferred polyester (meth)acrylate oligomer is a di- to tetra-functional acrylate oligomer obtained by esterifying tetrahydrophthalic anhydride, trimethylolpropane, and acrylic acid in a conventional manner.

[0184] Examples of the (3) polyfunctional urethane (meth)acrylate oligomer include a urethane reaction product of a (meth)acrylate monomer having at least one (meth)acryloyloxy group and a hydroxyl group in one molecule with a polyisocyanate, and a urethane reaction product of an isocyanate compound obtained by reacting a polyol with a polyisocyanate with a (meth)acrylate monomer having at least one (meth)acryloyloxy group and a hydroxyl group in one molecule.

[0185] In the production of a polyfunctional urethane (meth)acrylate oligomer, examples of the polyisocyanate used in the urethanization reaction include hexamethylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, diisocyanates obtained by hydrogenating aromatic isocyanates (for example, diisocyanates such as hydrogenated tolylene diisocyanate and hydrogenated xylylene diisocyanate), di- or triisocyanates such as triphenylmethane triisocyanate and dimethylene triphenyl triisocyanate, and polyisocyanates obtained by cyanurating a diisocyanate.

[0186] In the production of a polyfunctional urethane (meth)acrylate oligomer, examples of polyols used in the production of an isocyanate compound include the compounds exemplified above as polyhydric alcohols used in the production of a polyfunctional polyol (meth)acrylate oligomer (1). Specific examples of isocyanate compounds obtained by reacting the above polyols with polyisocyanates include trimethylolpropane toluylene diisocyanate. Examples of "compounds containing active hydrogen and an acryloyloxy group (or methacryloyloxy group)" used in the production of a polyfunctional urethane (meth)acrylate oligomer include compounds containing a hydroxyl group and an acryloyloxy group (or methacryloyloxy group). Specific examples include 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate.

[0187] Specific examples of polyfunctional urethane (meth)acrylate oligomers particularly suitable for use in the present invention include trimethylolpropane toluylene diisocyanate or reaction products of an isocyanurate group-containing polyisocyanate with a compound containing active hydrogen and a (meth)acryloyloxy group. More specific examples include triacrylate oligomers, trimethacrylate oligomers, diacrylate oligomers, or dimethacrylate oligomers of tris(2-hydroxyethyl)isocyanurate; triacrylate oligomers, trimethacrylate oligomers, diallylate oligomers, or dimethacrylate oligomers of di(2-hydroxyethyl)mono(2-hydroxyheptane)isocyanurate; and compounds (molecular weight 1200 or greater) containing (meth)acryloyloxy groups at both ends connected by urethane bonds. Commercially available polyfunctional urethane (meth)acrylate oligomers can be used. Specific examples of commercially available products include, but are not limited to, UN-3320HC (Negami Kogyo Co., Ltd.), UA-510H (Kyoeisha Chemical Co., Ltd.), CN968 (Sartomer Co., Ltd.), Eb-220 (Daicel Cytec Co., Ltd.), U6HA (Shin-Nakamura Chemical Co., Ltd.), etc. In the present invention, hexafunctional urethane acrylate oligomers can be particularly preferably used.

[0188] The hard coat layer may contain one or more types of (meth)acrylate oligomers as the component (A).

[0189] <Component (B)> [(Meth)acrylate Monomer] The (meth)acrylate monomer used as component (B) in the present invention is one in which a (meth)acryloyl group exists as a functional group within the molecule, and may be a monofunctional or bifunctional monomer. The upper limit of the molecular weight of the monomer is less than 200, preferably 190 or less, and more preferably 180 or less. If the molecular weight of the monomer is 200 or more, adhesion to the high-hardness resin layer may be significantly reduced. The lower limit of the molecular weight of the monomer is approximately 100. Furthermore, the viscosity of the monomer at 25°C is preferably 15 cps or less, more preferably 10 cps or less, even more preferably 7 cps or less, and particularly preferably 5 cps or less. The viscosity of the monomer can be measured at 25°C using a Sekonic VM-100A-L vibration viscometer.

[0190] Examples of monofunctional monomers having a molecular weight of less than 200 include (meth)acrylic acid and (meth)acrylic acid esters. Specific examples of (meth)acrylate monomers include ethyl (meth)acrylate, cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, benzyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-(allyloxymethyl)methyl acrylate, diethylene glycol monoethyl ether acrylate, and acrylic acid=3,3,5-trimethylcyclohexyl acrylate.

[0191] Specific examples of bifunctional (meth)acrylate monomers having a molecular weight of less than 200 include 1,4-butanediol diacrylate and ethylene glycol di(meth)acrylate.

[0192] The hard coat layer may contain one or more types of (meth)acrylate monomers as the component (B).

[0193] <Component (C)> [Photopolymerization Initiator] Examples of the photopolymerization initiator include monofunctional photopolymerization initiators. Specific examples include acetophenone-based initiators such as 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone [Darocur 2959: manufactured by Merck]; α-hydroxy-α,α'-dimethylacetophenone [Darocur 1173: manufactured by Merck]; methoxyacetophenone, 2,2'-dimethoxy-2-phenylacetophenone [Irgacure 651: manufactured by BASF Corporation], and 1-hydroxy-cyclohexylphenyl ketone [Irgacure 184: manufactured by BASF Corporation]; benzoin ether-based initiators such as benzoin ethyl ether and benzoin isopropyl ether; and other examples include halogenated ketones, acylphosphinoxides, and acylphosphonates.

[0194] <Component (D)> [Surface Modifier] The surface modifier is an agent that changes the surface performance of the hard coat layer, such as a leveling agent, an antistatic agent, a surfactant, a water- and oil-repellent agent, inorganic particles, or organic particles.

[0195] Examples of the leveling agent include polyether-modified polyalkylsiloxane, polyether-modified siloxane, polyester-modified hydroxyl group-containing polyalkylsiloxane, polyether-modified polydimethylsiloxane having an alkyl group, modified polyether, and silicon-modified acrylic.

[0196] Examples of the antistatic agent include glycerin fatty acid ester monoglycerides, glycerin fatty acid ester organic acid monoglycerides, polyglycerin fatty acid esters, sorbitan fatty acid esters, cationic surfactants, and anionic surfactants.

[0197] Examples of the surfactant and the water / oil repellent agent include fluorine-containing surfactants and water / oil repellents such as an oligomer containing a fluorine-containing group and a lipophilic group, and an oligomer containing a fluorine-containing group, a hydrophilic group, a lipophilic group, and a UV-reactive group.

[0198] Examples of the inorganic particles include silica particles, alumina particles, zirconia particles, and glass particles.

[0199] Examples of the organic particles include acrylic particles and silicon particles.

[0200] The hard coat layer may contain one or more types of surface modifiers.

[0201] [Method for forming hard coat layer] The method for forming the hard coat layer is not particularly limited. For example, the hard coat layer can be formed by applying a hard coating composition onto a layer (high-hardness resin layer) located below the hard coat layer, followed by photopolymerization.

[0202] The method for applying the hard coating composition (polymerizable composition) is not particularly limited, and any known method can be used, such as spin coating, dipping, spraying, slide coating, bar coating, roll coating, gravure coating, meniscus coating, flexographic printing, screen printing, beat coating, and sieving.

[0203] The lamp used for light irradiation in photopolymerization has an emission distribution of light wavelengths of 420 nm or less. Examples include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, chemical lamps, black light lamps, microwave-excited mercury lamps, and metal halide lamps. Among these, high-pressure mercury lamps and metal halide lamps are preferred because they efficiently emit light in the active wavelength range of the initiator and do not emit much short-wavelength light that would reduce the viscoelastic properties of the resulting polymer due to crosslinking, or much long-wavelength light that would heat and evaporate the reaction composition.

[0204] The irradiation intensity of the lamp is a factor that determines the degree of polymerization of the resulting polymer, and is appropriately controlled depending on the performance of the target product. When a typical cleavage-type initiator having an acetophenone group is blended, the irradiance is 0.1 to 300 mW / cm. ２ In particular, when a metal halide lamp is used, the illuminance is set to 10 to 40 mW / cm ２ It is preferable to set the following.

[0205] The photopolymerization reaction is inhibited by oxygen in the air or oxygen dissolved in the hard coating composition. Therefore, it is desirable to perform light irradiation using a method that can eliminate reaction inhibition by oxygen. One such method is to cover the hard coating composition with a film made of polyethylene terephthalate or Teflon to prevent contact with oxygen, and then irradiate the hard coating composition with light through the film. Alternatively, the composition may be irradiated with light through a light-transmitting window in an inert atmosphere in which oxygen is replaced with an inert gas such as nitrogen gas or carbon dioxide gas.

[0206] When light irradiation is performed in an inert atmosphere, a certain amount of inert gas is always introduced to maintain the atmospheric oxygen concentration at a low level. The introduction of this inert gas generates an airflow on the surface of the hard coating composition, causing monomer evaporation. To suppress the level of monomer evaporation, the airflow velocity of the inert gas is preferably 1 m / sec or less, more preferably 0.1 m / sec or less, relative to the laminate coated with the hard coating liquid moving under the inert gas atmosphere. By setting the airflow velocity within the above range, monomer evaporation due to the airflow can be substantially suppressed.

[0207] In order to improve the adhesion of the hard coat layer, the coated surface may be pretreated by known methods such as sandblasting, solvent treatment, corona discharge treatment, chromic acid treatment, flame treatment, hot air treatment, ozone treatment, ultraviolet treatment, and primer treatment with a resin composition.

[0208] The hard coat layer may be further modified. For example, it may be subjected to one or more of anti-glare treatment, anti-reflection treatment, antifouling treatment, anti-static treatment, weather resistance treatment, and anti-glare treatment. The treatment method is not particularly limited, and known methods can be used. For example, a method of applying a reflection-reducing coating, a method of depositing a dielectric thin film, a method of applying an anti-static coating, etc. may be mentioned.

[0209] The anti-glare treatment is not particularly limited, but may include a method using an anti-glare mold. For example, a high-hardness resin layer, a coating film obtained by applying a hard coating composition, and an anti-glare mold are first laminated in this order. Next, a method of photopolymerizing the hard coating composition and demolding the anti-glare mold is exemplified. The photopolymer of the hard coating composition (hard coat layer) will have a shape that reflects the rough surface of the anti-glare mold at the contact surface with the anti-glare mold. The material of the anti-glare mold is not particularly limited as long as it transmits UV light, and glass, transparent resin, etc. can be used. Other anti-glare treatment methods include a method of adding particles to the hard coating composition and a method of treating the surface of the resulting hard coat layer. The haze of the hard coat layer can be adjusted by controlling the type of anti-glare mold used (surface haze, thickness, etc.) and the amount of particles added.

[0210] <Moldable Laminated Resin Sheet> The pencil hardness of the moldable laminated resin sheet is preferably 2H or higher, more preferably 2H to 4H, and even more preferably 3H to 4H. This is because a pencil hardness of 5H or higher causes cracks after thermoforming, so by setting the pencil hardness to 2H to 4H, both moldability and hardness can be achieved. The pencil hardness of the moldable laminated resin sheet refers to the hardness of the hardest pencil that does not leave a scratch when a pencil of gradually increasing hardness is pressed against the surface of the hard coat layer at an angle of 45 degrees and with a load of 750 g (pencil scratch hardness test in accordance with JIS K 5600-5-4:1999).

[0211] <Molded Article> According to one embodiment of the present invention, there is provided a molded article molded using the above-described moldable laminate resin sheet.

[0212] Although the molding method is not particularly limited, thermoforming is suitable in view of the characteristics of the moldable laminate resin sheet. Thermoforming can be carried out by a method commonly used in the field. Specific thermoforming methods include, for example, heat press molding, pressure molding, vacuum molding, and TOM molding.

[0213] The molding temperature is preferably 100 to 200°C.

[0214] Examples of the present invention will be described below, but the present invention is not limited to the embodiments of the examples.

[0215] For the purposes of the examples, the following materials were used as high hardness resins, but the present invention is not limited to these.

[0216] High-hardness resin (B4): Nippon Shokubai Polyimilex (registered trademark) PML203 (glass transition temperature: 135°C, melt flow rate at 230°C under a load of 3.8 kg: 1.6 g / 10 min, refractive index: 1.54)

[0217] The following materials were used as components constituting the hard coating composition, and were used in the blending ratios (parts by mass) shown in Table 1 below. 7600B (Component (A)): Mitsubishi Chemical Corporation, hexafunctional urethane acrylate oligomer UA-306i (Component (A)): Kyoeisha Chemical Corporation, hexafunctional urethane acrylate oligomer CN9006 (Component (A)): Sartomer Corporation, hexafunctional urethane acrylate oligomer AOMA (Component (B)): Nippon Shokubai Corporation, 2-(allyloxymethyl)methyl acrylate (monofunctional) (molecular weight: 156, viscosity at 25°C: 2 cps). THF-A (component (B)): tetrahydrofurfuryl acrylate (monofunctional) manufactured by Kyoeisha Chemical (molecular weight: 156, viscosity at 25°C: 3 cps) 4EG-A (component not satisfying the requirements of component (B)): PEG200# diacrylate (bifunctional) (molecular weight: 302, viscosity at 25°C: 10 cps), manufactured by Kyoeisha Chemical Co., Ltd. IB-XA (component not satisfying the requirements of component (B)): Kyoeisha Chemical Company, isobornyl acrylate (monofunctional) (molecular weight: 222, viscosity at 25°C: 6 cps) Irgacure 184 (component (C)): 1-hydroxycyclohexyl phenyl ketone, manufactured by BASF Corporation. RS-90 (component (D)): fluorine-containing, hydrophilic, lipophilic, and UV-reactive group-containing oligomer, manufactured by DIC Corporation.

[0218] <Measurement of adhesion of molding laminate resin sheet (hard coat layer)> In accordance with JIS-K5400-5-6, 25 squares were cut with a cutter blade, six lines vertically and six lines horizontally at 1 mm intervals. Nichiban cellophane tape was firmly adhered to the cuts and peeled off at a 60° angle toward the user. A case in which the coating film did not peel off was evaluated as pass (◯), and a case in which even one square peeled off was evaluated as fail (×).

[0219] <Measurement of Scratch Resistance of Molding Laminated Resin Sheet (Hard Coat Layer)> Scratch resistance: 100 g / cm with #0000 steel wool ２ The test piece was reciprocated 15 times under a load of 0.05g, and a test piece with less than five scratches was rated as passing (◯), and a test piece with five or more scratches was rated as failing (×).

[0220] <Measurement of pencil hardness of moldable laminate resin sheet (hard coat layer)> The moldable laminate resin sheets produced in the examples and comparative examples were evaluated by a pencil scratch hardness test in accordance with JIS K 5600-5-4:1999. Pencils of gradually increasing hardness were pressed against the surface of the hard coat layer at an angle of 45 degrees and with a load of 750 g, and the hardness of the hardest pencil that did not leave a scratch was evaluated as the pencil hardness. A hardness of 2H or more was rated as pass (◯), and a hardness of less than 2H was rated as fail (×).

[0221] <Measurement of indentation test (indentation creep, maximum indentation depth) of molding laminate resin sheet (hard coat layer)> The indentation creep and maximum indentation depth of the hard coat layer were measured using a Fischer HM2000 LT. The measurement conditions were as follows: Maximum load: 3 mN, Holding time when maximum load was reached: 5 seconds, Loading rate, Unloading rate: 10 mN / sec

[0222] <Evaluation of the Presence or Absence of Cracks in the Hard Coat Layer (Moldability)> The moldable laminate resin sheets produced in the Examples and Comparative Examples were thermoformed, and the presence or absence of cracks in the 50 mm R portion was confirmed. Sheets in which no cracks were visually confirmed were rated as pass (◯), and sheets in which cracks were confirmed were rated as fail (×).

[0223] Example 1 Production of Pellets of High-Hardness Resin (B4) 500 ppm of phosphorus-based additive PEP-36 (manufactured by ADEKA Corporation) and 0.2% by mass of stearic acid monoglyceride (product name: H-100, manufactured by Riken Vitamin Co., Ltd.) were added to Polyimilex PML203 (manufactured by Nippon Shokubai Co., Ltd.), and mixed in a blender for 20 minutes. After mixing, the mixture was melt-kneaded at a cylinder temperature of 240°C using a twin-screw extruder (manufactured by Toshiba Machine Co., Ltd., TEM-26SS, L / D ≒ 40) with a screw diameter of 26 mm and equipped with a polymer filter with a 10 μm opening, extruded into strands, and pelletized using a pelletizer. Pellets of high-hardness resin (B4) were stably produced. The pellets of high hardness resin (B4) had an appearance of ◯ (transparent), a glass transition temperature of 135°C, a melt flow rate of 1.6 g / 10 min at 230°C under a load of 3.8 kg, and a refractive index of 1.54.

[0224] (Production of moldable laminated resin sheet) A laminate consisting of a base material layer and a high-hardness resin layer was molded using a multi-layer extrusion device having a single-screw extruder with a shaft diameter of 35 mm, a single-screw extruder with a shaft diameter of 65 mm, a feed block connected to each extruder, and a T-die connected to the feed block.

[0225] Specifically, the pelletized high-hardness resin (B4) obtained above was continuously introduced into a single-screw extruder with a shaft diameter of 35 mm and extruded under conditions of a cylinder temperature of 230° C. and a discharge rate of 2.6 kg / h. Also, a polycarbonate resin (Iupilon E-2000; manufactured by Mitsubishi Gas Chemical Company, Tg: 149° C., weight-average molecular weight (Mw): 34,200) was continuously introduced into a single-screw extruder with a shaft diameter of 65 mm and extruded under conditions of a cylinder temperature of 240° C. and a discharge rate of 50.0 kg / h.

[0226] The extruded high-hardness resin and polycarbonate resin were introduced into a feed block equipped with two-type, two-layer distribution pins, and the high-hardness resin and polycarbonate resin were laminated at a temperature of 240 ° C. The extruded sheet was then introduced into a T-die at a temperature of 240 ° C. and extruded into a sheet. The sheet was then cooled while transferring a mirror surface using three mirror-finished rolls set at temperatures of 120 ° C., 130 ° C., and 190 ° C. from the upstream side, to obtain a laminate of a high-hardness resin layer and a polycarbonate resin layer (substrate layer). The thickness of the resulting laminate was 2.0 mm, and the thickness of the high-hardness resin layer near the center was 60 μm.

[0227] Using each hard coating composition prepared according to the composition (parts by mass) in Table 1 below, a cured coating film (hard coat layer) was formed on the high-hardness resin layer of the laminate obtained above, to obtain each moldable laminate resin sheet, by the following procedure. The viscosity of each hard coating composition prepared according to the composition (parts by mass) in Table 1 below was measured at 25°C using a Sekonic VM-100A-L vibration viscometer, and the following values ​​were obtained: Example 1: 50 cps, Example 2: 65 cps, Example 3: 40 cps, Example 4: 70 cps, Comparative Example 1: 146 cps, Comparative Example 2: 52 cps, Comparative Example 3: 54 cps, Comparative Example 4: 200 cps, Comparative Example 5: 210 cps. The hard coating composition was placed on the high-hardness resin layer side of a laminate consisting of a high-hardness resin layer and a polycarbonate resin layer (substrate layer) heated in a hot-air circulation dryer set at 100°C, and then drawn with a bar coater to a cured coating thickness of 5 to 10 μm. A 100 μm-thick PET film was placed on top and leveled with a hand roller. This was then irradiated with ultraviolet light from a metal halide lamp with a power density of 120 W / cm at a position 14 cm below the light source and a conveyor speed of 1.0 m / min to form a cured coating (hard coat layer). After curing, the PET film was peeled off to obtain a moldable laminate resin sheet having a cured coating of the hard coating composition.

[0228] (Production of Molded Body) The moldable laminate resin sheet produced above was hot-pressed to produce a molded body. The hot press used was a servomotor-driven clamping mechanism, with a maximum clamping force of 3,000 kgf. The produced moldable laminate resin sheet was placed in a tray dryer set at 120°C and preheated for 3 minutes. The temperature of the sheet removed from the tray dryer was 80°C. After removing the moldable laminate resin sheet from the tray dryer, it was placed in the lower mold of an aluminum heat press mold (Figure 1) within 50 seconds. The moldable laminate resin sheet was hot-press molded using an aluminum heat press mold (Figure 1) with a clearance (the gap between the upper and lower molds for sandwiching the moldable sheet) of 2 mm and a curvature radius R of 50 mm for the lower mold. The temperatures of both the upper and lower molds were 138°C, the clamping force was 200 kgf, and the pressing time was 3 minutes.

[0229] The evaluation results of the obtained moldable laminate resin sheets are shown in Table 1 below. The moldable laminate resin sheets of Examples 1 to 4 satisfied all of the performance requirements. On the other hand, the moldable laminate resin sheets of Comparative Examples 1 to 5 did not satisfy all of the performance requirements, and were overall judged to be unsatisfactory.

[0230]

[0231] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims.

Claims

1. A moldable laminate resin sheet comprising: a high-hardness resin layer containing a high-hardness resin; a base layer containing a polycarbonate resin (a1) arranged on one side of the high-hardness resin layer; and a hard coat layer arranged on the other side of the high-hardness resin layer, wherein the hard coat layer has an indentation creep of 7.0% or less and a maximum indentation depth of 890 nm or less in an indentation test, and the hard coat layer is made of a hard coating composition containing: (A) a 2-15 functional (meth)acrylate oligomer; (B) a 1-2 functional (meth)acrylate monomer having a molecular weight of less than 200; (C) a photopolymerization initiator; and (D) a surface modifier, and the content of the (C) component is 1.2 to 1.8 parts by mass per 100 parts by mass of the total of the (A), (B), (C) and (D) components.

2. The molding laminate resin sheet according to claim 1, wherein the indentation creep in the indentation test is 5.3 to 7.0%, and the maximum indentation depth is 700 to 890 nm.

3. The moldable laminate resin sheet according to claim 1 or 2, wherein the content of said component (A) is 40 to 70 parts by mass per 100 parts by mass of the total of said components (A), (B), (C), and (D), the content of said component (B) is 20 to 55 parts by mass per 100 parts by mass of the total of said components (A), (B), (C), and (D), and the content of said component (D) is 0.1 to 10 parts by mass per 100 parts by mass of the total of said components (A), (B), (C), and (D).

4. The molding laminate resin sheet according to any one of claims 1 to 3, wherein the polycarbonate resin (a1) is an aromatic polycarbonate resin.

5. The aromatic polycarbonate resin is represented by the following formula (3a): The molding laminate resin sheet according to any one of claims 1 to 4, comprising a structural unit represented by:

6. The moldable laminate resin sheet according to any one of claims 1 to 5, wherein the content of the polycarbonate resin (a1) is 75 to 100 mass % relative to the total mass of the base layer.

7. The molding laminate resin sheet according to any one of claims 1 to 6, wherein the content of the high hardness resin is 70 to 100 mass % based on the total mass of the high hardness resin layer.

8. The moldable laminate resin sheet according to any one of claims 1 to 7, wherein the total thickness of said base layer and said high-hardness resin layer is 0.5 to 3.5 mm.

9. The moldable laminate resin sheet according to any one of claims 1 to 8, wherein the ratio of the thickness of the base material layer to the total thickness of the base material layer and the high-hardness resin layer is 75% to 99%.

10. The moldable laminate resin sheet according to any one of claims 1 to 9, wherein the surface of the hard coat layer has a pencil hardness of 2H or more.

11. A molded product formed using the moldable laminate resin sheet according to any one of claims 1 to 10.

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