JP7762083B2 - Laminated resin sheet for molding and molded product using same - Google Patents

Description

The present invention relates to a moldable laminate resin sheet and a molded article using the same.

Resin molded articles are used in automobile interior parts such as instrument covers, housings for home appliances, office equipment, personal computers, and small portable devices, and touch panel display surfaces for mobile phone terminals and other devices. Resin molded articles used for these applications are manufactured by molding resin sheets.

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 excels in transparency, lightness, and impact resistance, and is ideally suited for the above-mentioned applications.

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 also provides a method for producing a curved member that has excellent abrasion resistance, hot bending properties, and adhesion after hot bending.

However, as described in Patent Document 1, the outermost surface of polycarbonate resin molded products does not have sufficient pencil hardness, making them susceptible to scratches when coming into contact with hard components. This poses a problem as they cannot be used for applications requiring high surface hardness, such as the housings of small portable devices or the touch panel display surfaces of mobile phone terminals and the like.

WO2021/070632

The present invention aims to provide a moldable laminated resin sheet that has high hardness and scratch resistance, excellent adhesion, and easy formability.

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 layer and further providing a hard coat layer containing a specific component on the high-hardness resin layer.
<1> A high-hardness resin layer containing a high-hardness resin;
a substrate layer containing a polycarbonate resin (a1) disposed on one surface side of the high-hardness resin layer;
a hard coat layer disposed on the other surface side of the high-hardness resin layer,
the hard coat layer has a plastic deformation rate of 34 to 60%;
The hard coat layer is
(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 and a viscosity of 15 cps or less at 25°C;
(C) a photopolymerization initiator; and (D) a surface modifier.
the content of the component (A) is 40 to 80 mass% based on the total content of the components (A) and (B),
the content of the component (B) is 20 to 60 mass% based on the total content of the component (A) and the component (B),
the content of the component (C) is 0.1 to 10 parts by mass per 100 parts by mass of the total of the components (A) and (B),
In the moldable laminate resin sheet, the content of the component (D) is 0.1 to 10 parts by mass per 100 parts by mass of the total of the components (A) and (B).
<2> The moldable laminate resin sheet according to the above <1>, wherein the polycarbonate resin (a1) is an aromatic polycarbonate resin.
<3> The aromatic polycarbonate resin is represented by the following formula (3a):
The molding laminate resin sheet according to the above item <2>, which contains a structural unit represented by the following formula:
<4> The moldable laminate resin sheet according to any one of the above items <1> to <3>, wherein the content of the polycarbonate resin (a1) is 75 to 100% by mass relative to the total mass of the base layer.
<5> The high-hardness resin is
The following general formula (1):
(wherein ^R1 is a hydrogen atom or a methyl group, and ^R2 is an alkyl group having 1 to 18 carbon atoms.)
and a (meth)acrylic acid ester structural unit (a) represented by the following general formula (2):
(wherein ^R3 is a hydrogen atom or a methyl group, and ^R4 is a cyclohexyl group which may be substituted with a hydrocarbon group having 1 to 4 carbon atoms.)
and a copolymer (B1) containing an aliphatic vinyl structural unit (b) represented by the formula:
a resin (B2) which is a copolymer containing 6 to 77% by mass of (meth)acrylic acid ester structural units, 15 to 71% by mass of styrene structural units, and 8 to 23% by mass of unsaturated dicarboxylic acid structural units;
The following formula (5):
a resin (B3) which is a polymer containing a structural unit (c) represented by the following formula:
a resin (B4) which is a copolymer containing 5 to 20% by mass of styrene structural units, 60 to 90% by mass of (meth)acrylic acid ester structural units, and 5 to 20% by mass of N-substituted maleimide structural units;
The following formula (7):
Resin (B5) is a polymer containing a structural unit (e) represented by the formula: and 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 units.
The molding laminate resin sheet according to any one of the above items <1> to <4>, which includes at least one selected from the group consisting of:
<6> The resin (B3) is represented by the following formula (6):
The moldable laminate resin sheet according to the above item <5>, wherein the copolymer further contains a structural unit (d) represented by the following formula:
<7> The moldable laminate resin sheet according to any one of the above items <1> to <6>, wherein the content of the high-hardness resin is 70 to 100% by mass relative to the total mass of the high-hardness resin layer.
<8> The moldable laminate resin sheet according to any one of the above items <1> to <7>, 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 a ratio of a thickness of the base material layer to a 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 the above items <1> to <9>, wherein the viscosity of the hard coating composition is 400 cps or less at 25°C.
<11> The moldable laminate resin sheet according to any one of <1> to <10> above, wherein the hard coat layer has a surface with a pencil hardness of 2H or more.
<12> A molded article molded using the moldable laminate resin sheet according to any one of <1> to <11> above.

The present invention provides a moldable laminate resin sheet that has high hardness and scratch resistance, is less likely to cause appearance defects during molding, and has excellent adhesion, as well as a resin molded product made using the same.

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.

The present invention will be explained in detail below using manufacturing examples and examples, but the present invention is not limited to the manufacturing examples and examples shown, and can be modified in any way as long as it does not significantly deviate from the content of the present invention.

The moldable laminate resin sheet of the present invention (hereinafter also referred to simply as "resin sheet") includes 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. That is, the substrate layer, the high-hardness resin layer, and the hard-coat layer are disposed 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 substrate 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.

The high-hardness resin layer and hard-coat layer need only be provided on at least one side of the substrate layer, with no particular restrictions on the configuration of the other side. High-hardness resin layers may also be provided on both sides of the substrate layer, in which case a hard-coat layer can be provided on one or both of the high-hardness resin layers. When high-hardness resin layers are 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 minimal warping.

In the present invention, the plastic deformation ratio of the hard coat layer is 34 to 60%, preferably 36 to 57%, and more preferably 38 to 55%. This makes it possible to prevent the occurrence of appearance abnormalities such as cracks during molding while maintaining sufficient hardness. In the present invention, the plastic deformation ratio of the hard coat layer is a value measured using a Fischer HM2000 LT, specifically, a value measured using the method described in the Examples section below.

The above-mentioned moldable laminate resin sheet can be suitably used to manufacture molded products with bent shapes that require high hardness. For example, it can successfully produce components with flat sections and continuous bent sections, allowing for the provision of products with novel designs and functions.

When attempting to manufacture molded products with the above shapes using conventional resin sheets, many problems occurred, such as cracks occurring during thermoforming processes such as heat press molding, vacuum molding, pressure molding, and TOM molding. Therefore, in order to prevent cracks from occurring during thermoforming, it was necessary to devise measures such as reducing the hardness of the hard coat. However, while reducing the hard coat's hardness improves thermoformability, new problems arose: the hard coat became soft, making it more susceptible to scratches, and its chemical resistance decreased.

In contrast, according to the present invention, cracking is suppressed as described above, making it possible to provide a thermoformable resin sheet without reducing the hardness of the hard coat. Because the moldable laminate resin sheet of the present invention has a hard hard coat layer on the surface, it is scratch-resistant and highly chemical-resistant. 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 for automobiles, and curved housings and front panels for mobile phone terminals, personal computers, tablet PCs, car navigation systems, etc.

Hereinafter, each of the constituent members of the resin sheet according to the present invention will be described.
<Base material layer>
The substrate layer contains a polycarbonate resin (a1). The substrate layer may further contain other resins, additives, etc.

(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 represented by the following formula (3a):

Specifically, aromatic polycarbonate resins (for example, 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 a polycarbonate resin, a resin sheet having superior impact resistance can be obtained.

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 to control the glass transition temperature of the polycarbonate resin. Polycarbonate resins to which such terminal terminators have been added can also be used in the present invention.

In the formula, ^R5 represents an alkyl group having 8 to 36 carbon atoms or an alkenyl group having 8 to 36 carbon atoms; each ^R6 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 atom, 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 "alkenyl group" may be linear or branched and may have a substituent.

The monohydric phenol represented by general formula (3) is preferably represented by the following general formula (4):

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.

The number of carbon atoms in ^R5 in general formula (3) or general formula (4) is more preferably within a specific numerical range. Specifically, the upper limit of the number of carbon atoms in ^R5 is preferably 36, more preferably 22, and particularly preferably 18. The lower limit of the number of carbon atoms in ^R5 is preferably 8, and more preferably 12.

When the upper limit of the number of carbon atoms in ^R5 in general formula (3) or general formula (4) is appropriate, the solubility of the monohydric phenol (end terminator) in organic solvents tends to be high, which is preferable because it increases the productivity during the production of polycarbonate resins.

For example, when the carbon number of ^R5 is 36 or less, the productivity of polycarbonate resin production is high and the economic efficiency is also good. When the carbon number of ^R5 is 22 or less, the monohydric phenol has particularly excellent solubility in organic solvents, and the productivity of polycarbonate resin production can be significantly increased and the economic efficiency is also improved. An example of a polycarbonate resin using such a monohydric phenol is Iupizeta T-1380 (manufactured by Mitsubishi Gas Chemical Company).

If the lower limit of the number of carbon atoms in ^R5 in general formula (3) or general formula (4) is appropriate, the glass transition point of the polycarbonate resin will not be too high, and the polycarbonate resin will have suitable thermoformability, which is preferable.

For example, when a monohydric phenol represented by general formula (4) in which ^R5 is an alkyl group having 16 carbon atoms is used as an 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 solvent solubility during the production of the polycarbonate resin, making this particularly preferred.

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.

The weight-average molecular weight of 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 is preferable because it can improve impact resistance. On the other hand, a weight-average molecular weight of 75,000 or less is preferable because it allows the substrate layer to be formed with a small heat source and maintains thermal stability even under high-temperature molding conditions. Note that, in this specification, the weight-average molecular weight is the weight-average molecular weight measured by gel permeation chromatography (GPC) and converted into standard polystyrene.

The Tg of 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 polycarbonate resin (a1) can be controlled by appropriately adjusting the type and combination of structural units of 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.

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

The content of polycarbonate resin (a1) in the substrate layer is preferably 75 to 100% by mass, more preferably 90 to 100% by mass, and particularly preferably 100% by mass, relative to the total mass of the substrate layer. A polycarbonate resin content of 75% by mass or more is preferred because it can further improve impact resistance.

(Other resins)
The other resin that may be contained in the base layer is not particularly limited, but examples thereof include polyester resins.
The polyester resin preferably contains terephthalic acid as the dicarboxylic acid component, but may contain a dicarboxylic acid component other than terephthalic acid.

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.

When other resins are included, the content 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 base layer.

(Additives)
The additives that may be contained in the base layer can be those 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.

The amount of additive is preferably 0 to 10% by mass, more preferably 0 to 7% by mass, and particularly preferably 0 to 5% by mass, relative to the total mass of the substrate layer.

The method for mixing the additives and resin is not particularly limited, and methods such as compounding the entire amount, dry blending the masterbatch, or dry blending the entire amount can be used.

(Base material layer)
The thickness of the substrate 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.

<High hardness resin layer>
The high-hardness resin layer contains a high-hardness resin. Other resins, additives, etc. may also be included 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.

[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).

(Resin (B1))
Resin (B1) is a copolymer containing (meth)acrylic acid ester structural units (a) represented by general formula (1) and aliphatic vinyl structural units (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.

In the formula, R ¹ is a hydrogen atom or a methyl group, preferably a methyl group.
Furthermore, ^R2 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, ^R2 is preferably a methyl group or an ethyl group, and more preferably a methyl group.

When ^R2 is 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 when ^R1 is a methyl group and ^R2 is a methyl group, the (meth)acrylic acid ester structural unit (a) represented by general formula (1) becomes a methyl methacrylate structural unit.

Resin (B1) may contain only one type of (meth)acrylic acid ester structural unit (a) represented by general formula (1), or may contain two or more types.

In the formula, ^R3 is a hydrogen atom or a methyl group, and is preferably a hydrogen atom.
^R4 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.

When ^R3 is a hydrogen atom and ^R4 is a cyclohexyl group, the aliphatic vinyl structural unit (b) represented by general formula (2) is a vinylcyclohexane structural unit.

Resin (B1) may contain only one type of aliphatic vinyl structural unit (b) represented by general formula (2), or two or more types.

In this specification, a "hydrocarbon group" may be linear, branched, or cyclic, and may have a substituent.

The other structural unit is not particularly limited, but examples thereof include a structural unit derived from an aromatic vinyl monomer containing an unhydrogenated aromatic double bond, which is generated in the process of producing the resin (B1) by polymerizing a (meth)acrylic acid ester monomer and an aromatic vinyl monomer and then hydrogenating the aromatic double bond derived from the aromatic vinyl monomer. A specific example of the other structural unit is a styrene structural unit.
The resin (B1) may contain only one type of other structural unit, or may contain two or more types of other structural units.

The total content of the (meth)acrylic acid ester structural units (a) and the aliphatic vinyl structural units (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 resin (B1).

The content of the (meth)acrylic acid ester structural unit (a) represented by general formula (1) is preferably 65 to 80 mol %, and more preferably 70 to 80 mol %, relative to all structural units of 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 with excellent adhesion to the substrate layer and surface hardness to be obtained. 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.

The content of the aliphatic vinyl structural unit (b) represented by general formula (2) is preferably 20 to 35 mol %, and more preferably 20 to 30 mol %, relative to all structural units of resin (B1). A content of the aliphatic vinyl structural unit (b) of 20 mol % or more is preferred because it can prevent warping under high-temperature and high-humidity conditions. On the other hand, a content of the aliphatic vinyl structural unit (b) of 35 mol % or less is preferred because it can prevent peeling at the interface with the substrate layer.

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 the total structural units of resin (B1).

In this specification, the term "copolymer" may refer to any of a random copolymer, a block copolymer, and an alternating copolymer structure.

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

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 shaping roll, or batch-type thermal shaping using a mirrored mold or shaping mold.

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

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).

Furthermore, a particularly preferred embodiment is one in which the high-hardness resin is a resin (B1) that is a copolymer containing 75 mol % of structural units represented by general formula (1) (R ^{1 and} R ² are both methyl groups; methyl methacrylate) and 25 mol % of structural units represented by general formula (2) (R 3 is a hydrogen atom, R ⁴ is a cyclohexyl group; vinylcyclohexane), the polycarbonate resin (a1) is a polycarbonate resin containing structural units represented by formula (3a), and the end terminator is a monohydric phenol represented by general formula (4) (R ⁵ has 8 to 22 carbon atoms).

There are no particular limitations on the method for producing resin (B1), 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 bonds derived from the aromatic vinyl monomer, is suitable.

The aromatic vinyl monomer is not particularly limited, but examples include styrene, α-methylstyrene, p-hydroxystyrene, alkoxystyrene, chlorostyrene, and derivatives thereof. Of these, styrene is preferred as the aromatic vinyl monomer.

The (meth)acrylic acid ester monomer and the aromatic vinyl monomer can be polymerized by a known method, such as bulk polymerization or solution polymerization.
The bulk polymerization method 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 above-mentioned monomer composition may contain a chain transfer agent, if necessary.

The polymerization initiator is not particularly limited, but examples 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, as well as azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), and 2,2'-azobis(2,4-dimethylvaleronitrile). These can be used alone or in combination of two or more.

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

Solvents used in solution polymerization methods include, for example, 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.

The solvent used in the hydrogenation reaction to hydrogenate 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 polymerization solvent described above. Examples 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.

There are no particular restrictions on the hydrogenation method, 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 molecular chain scission and hydrogenation of ester moieties do not occur or occur very little.

Examples of catalysts used in hydrogenation reactions include solid catalysts in which metals such as nickel, palladium, platinum, cobalt, ruthenium, and rhodium, or oxides, salts, or complex compounds of these metals, are supported on porous supports such as carbon, alumina, silica, silica-alumina, and diatomaceous earth.

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 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%. An unhydrogenated ratio of less than 30% is preferable because it allows for the production of a resin with excellent transparency. The structural units of the unhydrogenated portion can become other structural units in resin (B1).

(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, and may further contain other structural units.

The (meth)acrylic acid ester monomer constituting the (meth)acrylic acid ester structural unit in resin (B2) is not particularly limited, but examples 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.

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

The styrene structural unit in the resin (B2) is not particularly limited, and any known styrene-based monomer can be used. From the viewpoint of ease of availability, examples of the styrene-based monomer include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, and t-butylstyrene. Of these, from the viewpoint of compatibility, styrene is preferred as the styrene-based monomer. 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.

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

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

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

Other structural units in the resin (B2) include, for example, N-phenylmaleimide.

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 the total structural units of resin (B2).

The total content of the above-mentioned (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 resin (B2).

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

The glass transition temperature of resin (B2) is preferably 90 to 150°C, more preferably 100 to 150°C, and particularly preferably 115 to 150°C.

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

When resin (B2) 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). Furthermore, a particularly preferred embodiment uses a monohydric phenol represented by general formula (4) ( ^R5 has 8 to 22 carbon atoms) as an end terminator. Examples of such polycarbonate resins include Iupizeta T-1380 (manufactured by Mitsubishi Gas Chemical Company) and Iupilon E-2000 (manufactured by Mitsubishi Engineering-Plastics Corporation).

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

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

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

(Resin (B3))
Resin (B3) is a polymer containing a structural unit (c) represented by formula (5). In this case, the polymer preferably further contains a structural unit (d) represented by formula (6). The polymer may further contain other structural units.

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 resin (B3).

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 %, relative to all structural units of resin (B3).

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 the total structural units of resin (B3).

The total content of structural units (c) and structural units (d) 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 in resin (B3).

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

The glass transition temperature of resin (B3) is preferably 105 to 150°C, more preferably 110 to 140°C, and particularly preferably 110 to 135°C.

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

When resin (B3) 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). Furthermore, a particularly preferred embodiment uses a monohydric phenol represented by general formula (4) (wherein ^R5 has 8 to 22 carbon atoms) as the end terminator. 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 resin (B3) and Iupizeta T-1380 (manufactured by Mitsubishi Gas Chemical Company) as polycarbonate resin (a1).

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.

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

The method for producing resin (B3) is not particularly limited, but it can be produced using a method similar to the method for producing polycarbonate resin (a1) described above, except that bisphenol C is used as the monomer.

(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. Resin (B4) may further contain other structural units.

The styrene structural unit in the resin (B4) is not particularly limited, and any known styrene-based monomer can be used. From the viewpoint of ease of availability, examples of the styrene-based monomer include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, and t-butylstyrene. Of these, from the viewpoint of compatibility, styrene is preferred as the styrene-based monomer. 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.

The content of styrene structural units is 5 to 20% by mass, preferably 5 to 15% by mass, and more preferably 5 to 10% by mass, relative to the total mass of resin (B4).

The (meth)acrylic acid ester monomer constituting the (meth)acrylic acid ester structural unit in resin (B4) is not particularly limited, but examples 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.

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

Examples of the N-substituted maleimide structural units in 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. Among these, structural units derived from N-phenylmaleimide are preferred from the standpoint of compatibility with acrylic resins. The above-mentioned structural units derived from N-substituted maleimides may be included alone as N-substituted maleimide structural units, or two or more types may be included in combination.

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

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). In this case, general formula (1) and general formula (2) are the same as those for resin (B1) described above.

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 the total structural units of resin (B4).

The total content of 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 resin (B4).

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

The glass transition point of resin (B4) is preferably 110 to 150°C, more preferably 115 to 140°C, and particularly preferably 115 to 135°C.

A specific example of resin (B4) is Delpet PM120N (manufactured by Asahi Kasei Corporation). The above-mentioned resins (B4) may be used alone or in combination of two or more.

When resin (B4) is used as the high-hardness resin, a preferred embodiment is one in which a polycarbonate resin containing structural units of formula (3a) is used as polycarbonate resin (a1). Furthermore, a particularly preferred embodiment is one in which a monohydric phenol represented by general formula (4) (wherein ^R5 has 8 to 22 carbon atoms) is used as the end-terminator. 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).

The method for producing resin (B4) is not particularly limited, but it can be produced by solution polymerization, bulk polymerization, etc.

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

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 resin (B5).

Examples of other structural units include structural units represented by formula (5) and structural units represented by formula (6). In this case, formulas (5) and (6) are the same as those for resin (B3) described above.

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 the total structural units of resin (B5).

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

The glass transition temperature of resin (B5) is preferably 120 to 200°C, more preferably 130 to 190°C, and particularly preferably 140 to 190°C.

Specific examples of resin (B5) include 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 types.

When resin (B5) is used as the high-hardness resin, a preferred embodiment uses a polycarbonate resin containing the 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). 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) as polycarbonate resin (a1).

When resin (B5) 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 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.

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

The method for producing resin (B5) is not particularly limited, but it can be produced using a method similar to the method for producing polycarbonate resin (a1) described above, except that bisphenol AP is used as the monomer.

(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.

The styrene structural units may be the styrene-based monomers described in resin (B4). Resin (B6) may contain these styrene structural units either alone or in combination of two or more.

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

Unsaturated dicarboxylic acid anhydride monomers constituting the unsaturated dicarboxylic acid structural units include, for example, acid anhydrides such as maleic acid, itaconic acid, citraconic acid, and aconitic acid. Of 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.

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

Resin (B6) may contain structural units other than the above structural units. Examples of other structural units include structural units represented by the following general formula (1) and structural units represented by the following general formula (2).

In the formula, ^R1 and ^R2 are the same as above.

In the formula, ^R3 and ^R4 are the same as above.

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 the total structural units of resin (B6).

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

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

Specific examples of resin (B6) include XIBOND140 and XIBOND160 (manufactured by Polyscope Co., Ltd.). The above-mentioned resin (B6) may be used alone or in combination of two or more types.

When resin (B6) is used as the high-hardness resin, a preferred embodiment is one in which a polycarbonate resin containing structural units of formula (3a) is used as polycarbonate resin (a1). Furthermore, a particularly preferred embodiment is one in which a monohydric phenol represented by general formula (4) (wherein ^R5 has 8 to 22 carbon atoms) is used as the end terminator. 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).

The method for producing resin (B6) is not particularly limited, but it can be produced by solution polymerization, bulk polymerization, etc.

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

The alloy is not particularly limited, but examples include an alloy of two types of resin (B1), an alloy of two types of resin (B2), an alloy of two types of resin (B3), an alloy of two types of resin (B4), an alloy of two types of resin (B5), an alloy of two types of resin (B6), an alloy of resin (B1) and resin (B2), an alloy of resin (B2) and resin (B4), an alloy of resin (B2) and another high-hardness resin, an alloy of resin (B2) and acrylic resin, an alloy of resin (B6) and acrylic resin, etc.

Other high-hardness resins include methyl methacrylate-styrene copolymers and acrylonitrile-butadiene-styrene copolymers.

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

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

The method for producing the alloy is not particularly limited, but examples include melt-kneading the material using a twin-screw extruder with a screw diameter of 26 mm at a cylinder temperature of 240°C, extruding the material into strands, and pelletizing the strands using a pelletizer.

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

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, relative to the total mass of the high-hardness resin layer.

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

The content of other resins is preferably 30% by mass or less, more preferably 20% by mass or less, and particularly preferably 0% by mass, relative to the total mass of the high-hardness resin layer.

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

[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 preferable because the surface hardness is high. On the other hand, a thickness of 250 μm or less is preferable because the impact resistance is high.

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

The method for laminating the high-hardness resin layer onto the base layer is not particularly limited, and examples include a method in which a separately formed base layer and a high-hardness resin layer are superimposed on each other and then heated and pressed together; a method in which a separately formed base layer and a high-hardness resin layer are superimposed on each other and then bonded together with an adhesive; a method in which the base layer and the high-hardness resin layer are co-extruded; and a method in which the base layer is integrated into a pre-formed high-hardness resin layer by in-mold molding. Of these, the co-extrusion molding method is preferred from the standpoints of manufacturing cost and productivity.

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, and the layer is 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, and then extruded into a sheet, and then cooled while passing through a forming roll to form a desired laminate.
The above method can be used in the same manner when laminating a high-hardness resin layer on a layer other than the substrate layer.

The total thickness of the base layer and 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 helps maintain the rigidity of the sheet. On the other hand, a total thickness of 3.5 mm or less is preferable because it helps prevent a decrease in touch sensor sensitivity when a touch panel is installed under the sheet.

The thickness of the base layer accounts for preferably 75% to 99% of the total thickness of the base layer and the high-hardness resin layer, more preferably 80% to 99%, and especially preferably 85% to 99%. By keeping it within this range, both hardness and impact resistance can be achieved.

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

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 and a viscosity of 15 cps or less at 25°C, (C) a photopolymerization initiator, and (D) a surface modifier. In this specification, photopolymerization initiator refers to a photoradical generator.

The content of the (meth)acrylate oligomer, which is component (A), is 40 to 80% by mass, preferably 50 to 75% by mass, and more preferably 55 to 75% by mass, based on the total content of components (A) and (B).

The content of the (meth)acrylate monomer, component (B), is 20 to 60% by mass, preferably 20 to 50% by mass, and more preferably 25 to 45% by mass, based on the total content of components (A) and (B).

The content of the photopolymerization initiator (component (C)) is 0.1 to 10 parts by mass, preferably 0.5 to 7 parts by mass, and more preferably 1 to 5 parts by mass, per 100 parts by mass of the combined total of components (A) and (B).

The content of the surface modifier (D) is 0.1 to 10 parts by mass, preferably 0.5 to 7 parts by mass, and more preferably 1 to 5 parts by mass, per 100 parts by mass of the combined total of the (A) and (B) components.

The viscosity of a hard coating composition containing components (A) through (D) at 25°C is preferably 400 cps or less, more preferably 300 cps or less, and most preferably 250 cps or less. The lower limit is usually around 30 cps. If the viscosity of a hard coating composition at 25°C exceeds 400 cps, the coating film will become thick during application, making it more susceptible to cracking after thermoforming and significantly reducing processability during cutting. The viscosity of a hard coating composition can be measured at 25°C using a Sekonic VM-100A-L vibration viscometer.

<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.

Specific examples of the component (A) include the polyfunctional (meth)acrylate oligomers shown below in (1) to (4).
(1) Polyfunctional polyol (meth)acrylate oligomers, i.e., polyacrylate or polymethacrylate oligomers 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 oligomers, i.e., oligomers of saturated or unsaturated polyester polyacrylates or polymethacrylates obtained from polyhydric alcohols (polyols), polycarboxylic acids (polybasic acids or polybasic carboxylic acids) or their anhydrides, and acrylic acid, methacrylic acid, or their derivatives.
(3) Polyfunctional urethane (meth)acrylate oligomers, i.e., urethane polyacrylate or urethane polymethacrylate oligomers obtained from polyisocyanates and compounds having active hydrogen and acryloyloxy groups or methacryloyloxy groups.
(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.

Examples of the polyhydric alcohols (polyols) 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 1,000, 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.

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 can be produced by a dehydration condensation reaction between a dibasic carboxylic acid (anhydride) and a polyol, and then the reaction product can be reacted with acrylic acid or methacrylic acid to obtain a polyfunctional polyester (meth)acrylate oligomer.

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 from 3 to 6 hydroxy groups, preferably from 3 to 4 hydroxy groups, and from 2 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 provide ethoxylated and/or propoxylated polyols, such as ethoxylated trimethylolpropane, propoxylated trimethylolpropane, ethoxylated glycerin, propoxylated glycerin, ethoxylated pentaerythritol, and propoxylated pentaerythritol.

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

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; trimellitic acid; pyromellitic acid; thiodiglycolic acid; thiodivaleric acid; diglycolic acid; and unsaturated dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid. Chlorides, anhydrides, or esters of these compounds 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 containing ester bonds. For example, excess polyols are reacted with dibasic acids (anhydrides) to produce low molecular weight compounds containing from about one to about six ester bonds and reactive hydroxy groups. The above polyols can be used alone or in combination to produce polyester polyols.
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.

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, it is more preferable to use acrylic acid.

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.

Preferred polyester (meth)acrylate oligomers are di- to tetra-functional acrylate oligomers obtained by a conventional esterification reaction between tetrahydrophthalic anhydride, trimethylolpropane, and acrylic acid.

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 per 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 per molecule.

In the production of polyfunctional urethane (meth)acrylate oligomers, examples of polyisocyanates used in the urethane reaction include hexamethylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, diisocyanates obtained by hydrogenating aromatic isocyanates (e.g., hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, and other diisocyanates), di- or triisocyanates such as triphenylmethane triisocyanate and dimethylene triphenyl triisocyanate, and polyisocyanates obtained by cyanurating diisocyanates.

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

Specific examples of polyfunctional urethane (meth)acrylate oligomers that are particularly preferably used in the present invention include trimethylolpropane toluylene diisocyanate, or a reaction product of an isocyanurate group-containing polyisocyanate with a compound containing active hydrogen and a (meth)acryloyloxy group.
More specific examples include a triacrylate oligomer, trimethacrylate oligomer, diacrylate oligomer, or dimethacrylate oligomer of tris(2-hydroxyethyl)isocyanurate; a triacrylate oligomer, trimethacrylate oligomer, diarylate oligomer, or dimethacrylate oligomer of di(2-hydroxyethyl)mono(2-hydroxyheptane)isocyanurate; and a compound (molecular weight of 1,200 or more) containing (meth)acryloyloxy groups at both ends connected by a urethane bond.
Commercially available polyfunctional urethane (meth)acrylate oligomers can be used. Specific examples of commercially available products include UN-3320HC (Negami Kogyo Co., Ltd.), UA-510H (Kyoeisha Chemical Co., Ltd.), CN968 (Sartomer Co., Ltd.), Eb-220 (Daicel Cytec Co., Ltd.), and U6HA (Shin-Nakamura Chemical Co., Ltd.), but are not limited thereto. In the present invention, hexafunctional urethane acrylate oligomers are particularly preferably used.

The hard coat layer may contain one or more types of (meth)acrylate oligomers, which are component (A).

<Component (B)> [(Meth)acrylate Monomer]
The (meth)acrylate monomer used as component (B) in the present invention is a monomer having a (meth)acryloyl group as a functional group in 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 viscosity of the monomer at 25°C is 15 cps, preferably 10 cps or less, 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.

Examples of monofunctional monomers with 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.

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

The hard coat layer may contain one or more types of (meth)acrylate monomers, which are component (B).

<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 [Darocure 2959: manufactured by Merck], α-hydroxy-α,α'-dimethylacetophenone [Darocure 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.

<Component (D)> [Surface modifier]
The surface modifiers are agents that change the surface properties of the hard coat layer, such as leveling agents, antistatic agents, surfactants, water and oil repellents, inorganic particles, and organic particles.

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.

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.

Examples of the surfactants and water/oil repellents include fluorine-containing surfactants and water/oil repellents, such as oligomers containing fluorine-containing groups and lipophilic groups, and oligomers containing fluorine-containing groups, hydrophilic groups, lipophilic groups, and UV-reactive groups.

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

Examples of the organic particles include acrylic particles and silicone particles.

The hard coat layer may contain one or more surface modifiers.

[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 (e.g., a high-hardness resin layer) located below the hard coat layer, and then photopolymerizing the applied composition.

The method for applying the hard coating composition (polymerizable composition) is not particularly limited, and known methods can be used. Examples include spin coating, dipping, spraying, slide coating, bar coating, roll coating, gravure coating, meniscus coating, flexographic printing, screen printing, beat coating, and spraying.

Lamps used for light irradiation in photopolymerization have an emission distribution with a light wavelength 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 could reduce the viscoelastic properties of the resulting polymer due to crosslinking, or long-wavelength light that could heat and evaporate the reaction composition.

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 preferably in the range of 0.1 to 300 mW/ ^cm² . In particular, it is preferable to use a metal halide lamp with an irradiance of 10 to 40 mW/ ^cm² .

The photopolymerization reaction is inhibited by oxygen in the air or oxygen dissolved in the hard coating composition. Therefore, it is desirable to carry out 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 has been replaced with an inert gas such as nitrogen gas or carbon dioxide gas.

When light irradiation is performed in an inert atmosphere, a certain amount of inert gas is always introduced to maintain a low oxygen concentration in the atmosphere. 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, and 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 keeping the airflow velocity within the above range, monomer evaporation due to the airflow is substantially suppressed.

To improve the adhesion of the hard coat layer, the coating surface may be pretreated. Examples of such treatments include well-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 using a resin composition.

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, anti-fouling treatment, anti-static treatment, weather resistance treatment, and anti-glare treatment. These treatment methods are not particularly limited, and known methods can be used. Examples include applying a reflection-reducing coating, vapor-depositing a dielectric thin film, and applying an anti-static coating.

The anti-glare treatment is not particularly limited, but examples 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 laminated in this order. Next, the hard coating composition is photopolymerized, and the anti-glare mold is demolded. 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 surface where it contacts 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 adding particles to the hard coating composition and 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.

<Moldable laminated resin sheet>
The pencil hardness of the laminated resin sheet for molding 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 laminated resin sheet for molding means 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).

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

The molding method is not particularly limited, but thermoforming is suitable due to the characteristics of the moldable laminate resin sheet. Thermoforming can be carried out by methods commonly used in the field. Specific thermoforming methods include, for example, heat press molding, pressure forming, vacuum forming, and TOM molding.

The molding temperature is preferably 100 to 200°C.

The following examples of the present invention are presented, but the present invention is not limited to these examples.

For the purposes of the examples, the following materials were used as the methacrylic resin (C-1) and styrene copolymer (D-1), but these are not intended to be limiting.

Methacrylic resin (C-1): ALTUGLAS (registered trademark) V020 manufactured by Arkema Inc. (weight average molecular weight: 127,000, glass transition temperature: 134°C, melt flow rate at 230°C under a load of 3.8 kg: 1.8 g/10 min, refractive index: 1.49, mm/mr/rr = 7.4 mol%/37.4 mol%/55.2 mol%)
Styrene copolymer (D-1): XIBOND160 manufactured by Polyscope ((d1)/(d2) = styrene/maleic anhydride = 78% by mass/22% by mass, weight average molecular weight: 69,500, glass transition temperature: 143°C, melt flow rate at 230°C under a load of 3.8 kg: 7.6 g/10 min, refractive index: 1.58) (corresponding to resin (B6))

The hard coating composition was made up of the following materials, which were used in the blending ratios (parts by mass) shown in Table 1 below.
CN968 (component (A)): manufactured by Sartomer, hexafunctional urethane acrylate oligomer. AOMA (component (B)): manufactured by Nippon Shokubai, 2-(allyloxymethyl)methyl acrylate (monofunctional).
THF (1000) (component (B)): tetrahydrofurfuryl methacrylate (monofunctional), manufactured by Kyoeisha Chemical
EG (component (B)): Ethylene glycol dimethacrylate (bifunctional), manufactured by Kyoeisha Chemical
4-EGA: PEG200# diacrylate (bifunctional), manufactured by Kyoeisha Chemical Co., Ltd.
1.6HX: 1,6-hexanediol dimethacrylate (bifunctional), manufactured by Kyoeisha Chemical
2EG: diethylene glycol dimethacrylate (bifunctional), manufactured by Kyoeisha Chemical
IB-X: Kyoeisha Chemical Company, isobornyl methacrylate (monofunctional)
TBCHA: 4-tert-butylcyclohexyl acrylate (monofunctional), manufactured by KJ Chemicals
#200: Cyclic trimethylolpropane formal acrylate (monofunctional), manufactured by Osaka Organic Chemical Industry Co., Ltd.
Irgacure 184 (component (C)): manufactured by BASF Corporation; 1-hydroxycyclohexyl phenyl ketone RS-90 (component (D)): manufactured by DIC Corporation; oligomer containing fluorine-containing groups, hydrophilic groups, lipophilic groups, and UV-reactive groups

<Measurement of Adhesion of Laminated Resin Sheet for Molding (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 then peeled off at a 60° angle toward the user. A case in which the coating film did not peel off was judged as pass (○), and a case in which even one square peeled off was judged as fail (×).

<Measurement of Scratch Resistance of Laminated Resin Sheet for Molding (Hard Coat Layer)>
Scratch resistance: A #0000 steel wool was used to reciprocate 15 times at a load of 100 g/cm ^2, and samples with less than five scratches were rated as pass (◯), and samples with five or more scratches were rated as fail (×).

<Measurement of pencil hardness of moldable laminated resin sheet (hard coat layer)>
The moldable laminated 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 considered acceptable.

<Measurement of plastic deformation rate of moldable laminate resin sheet (hard coat layer)>
The plastic deformation rate of the hard coat layer was measured using a Fischer HM2000 LT under the following conditions:
Maximum load: 3mN
Holding time when maximum load is reached: 5 seconds Loading rate, unloading rate: 10 mN/sec
Calculation method: 100 - Elastic deformation rate (%) = Plastic deformation rate (%)

<Evaluation of the presence or absence of cracks in the hard coat layer (formability)>
The moldable laminated resin sheets manufactured in the Examples and Comparative Examples were thermoformed, and the presence or absence of cracks was confirmed in the 50 mm R portion, the 75 mm R portion, and the 100 mm R portion, respectively. Those in which no cracks were visually confirmed were evaluated as passing (◯), and those in which cracks were confirmed were evaluated as failing (×).

Example 1
[Production of pellets of high hardness resin (B-1)]
50 parts by mass of the methacrylic resin (C-1) and 50 parts by mass of the styrene copolymer (D-1), for a total of 100 parts by mass, phosphorus-based additive PEP-36 (manufactured by ADEKA Corporation) 500 ppm, and stearic acid monoglyceride (product name: H-100, manufactured by Riken Vitamin Co., Ltd.) 0.2% by mass was added, and after mixing in a blender for 20 minutes, a 26 mm screw diameter twin-screw extruder (manufactured by Toshiba Machine Co., Ltd., TEM-26SS, L / D ≒ 40) equipped with a polymer filter having a mesh size of 10 μm was used, and the mixture was melt-kneaded at a cylinder temperature of 240 ° C., extruded into strands, and pelletized with a pelletizer. Pellets of high hardness resin (B-1) could be produced stably.
The pellets of high hardness resin (B-1) had an appearance of ◯ (transparent), a glass transition temperature of 121° C., a melt flow rate of 2.5 g/10 min at 230° C. under a load of 3.8 kg, and a refractive index of 1.54.

(Production of moldable laminated resin sheet)
A laminate consisting of a substrate 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.

Specifically, the high-hardness resin (B-1) obtained above was continuously introduced into a single-screw extruder with a shaft diameter of 35 mm and extruded at a cylinder temperature of 230°C and a discharge rate of 2.6 kg/h. Also, polycarbonate resin (Iupizeta T-1380; manufactured by Mitsubishi Gas Chemical Company, Tg: 125°C, weight-average molecular weight (Mw): 44,500) was continuously introduced into a single-screw extruder with a shaft diameter of 65 mm and extruded at a cylinder temperature of 240°C and a discharge rate of 50.0 kg/h.

The extruded high-hardness resin and polycarbonate resin were introduced into a feed block equipped with two-type, two-layer distributor pins, where the high-hardness resin and polycarbonate resin were laminated at a temperature of 240°C. The extruded material was then introduced into a T-die at a temperature of 240°C and extruded into a sheet. The sheet was then cooled while a mirror finish was transferred onto it using three mirror-finish rolls set at temperatures of 120°C, 130°C, and 190°C from the upstream side, yielding 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 was 60 μm near the center.

On the high-hardness resin layer side of the laminate obtained above, each hard coating composition prepared according to the composition (parts by mass) in Table 1 below was used to form a cured coating film (hard coat layer) on the polycarbonate resin layer (substrate layer) according to the following procedure, thereby obtaining each moldable laminate resin sheet.
The hard coating composition was applied to a laminate of a high-hardness resin layer and a polycarbonate resin layer (substrate layer) heated in a hot-air circulating dryer set at 100°C, and then coated with a bar coater to a thickness of 5-10 μm after curing. A 100 μm-thick PET film was then placed on top and leveled with a hand roller. A cured coating (hard coat layer) was formed by irradiating the laminate 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. After curing, the PET film was peeled off to obtain a moldable laminate resin sheet having a cured coating of the hard coating composition.

(Production of Molded Body)
The moldable laminated resin sheet produced above was hot-pressed to produce a molded body. The hot-press machine used was a servomotor-driven mold clamping machine, and the maximum mold clamping force was 3000 kgf.
The produced laminated resin sheet for molding was placed in a tray dryer set at 120°C and preheated for 3 minutes. The temperature of the sheet when taken out of the tray dryer was 80°C.
The laminated resin sheet for molding was removed from the tray dryer and then placed in the lower mold of an aluminum hot press mold (FIG. 1) within 50 seconds.
The moldable laminated resin sheet was hot-press molded using an aluminum hot-press mold (Figure 1) with a clearance (the gap between the upper and lower molds to sandwich the moldable sheet) of 2 mm and a lower mold with a radius of curvature R of 50 mm. The temperatures of the upper and lower molds were both 122°C, the mold clamping force was 200 kgf, and the pressing time was 3 minutes.

The evaluation results of the obtained moldable laminate resin sheets are shown in Table 2 below. The moldable laminate resin sheets of Examples 1 to 6 satisfied all performance criteria. On the other hand, the moldable laminate resin sheets of Comparative Examples 1 to 6 did not satisfy all performance criteria and were overall judged to be unsatisfactory.

While 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 may be embodied in a variety of other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. These embodiments and their variations are within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as set forth in the claims.

Claims (12)

a high-hardness resin layer containing a high-hardness resin;
a substrate layer containing a polycarbonate resin (a1) disposed on one surface side of the high-hardness resin layer;
a hard coat layer disposed on the other surface side of the high-hardness resin layer,
the hard coat layer has a plastic deformation rate of 34 to 60%;
The hard coat layer is
(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 and a viscosity of 15 cps or less at 25°C;
(C) a photopolymerization initiator; and (D) a surface modifier.
the content of the component (A) is 50 to 75 mass% based on the total content of the components (A) and (B),
the content of the component (B) is 20 to 50 mass% based on the total content of the components (A) and (B),
the content of the component (C) is 0.1 to 10 parts by mass per 100 parts by mass of the total of the components (A) and (B),
The moldable laminate resin sheet, wherein the content of the component (D) is 0.1 to 10 parts by mass per 100 parts by mass of the total of the components (A) and (B). The moldable laminate resin sheet according to claim 1, wherein the polycarbonate resin (a1) is an aromatic polycarbonate resin. The aromatic polycarbonate resin is represented by the following formula (3a):
The molding laminate resin sheet according to claim 2, comprising a structural unit represented by the formula: The moldable laminate resin sheet according to any one of claims 1 to 3, wherein the content of the polycarbonate resin (a1) is 75 to 100 mass% relative to the total mass of the base material layer. The high-hardness resin is
The following general formula (1):
(wherein ^R1 is a hydrogen atom or a methyl group, and ^R2 is an alkyl group having 1 to 18 carbon atoms.)
and a (meth)acrylic acid ester structural unit (a) represented by the following general formula (2):
(wherein ^R3 is a hydrogen atom or a methyl group, and ^R4 is a cyclohexyl group which may be substituted with a hydrocarbon group having 1 to 4 carbon atoms.)
and a copolymer (B1) containing an aliphatic vinyl structural unit (b) represented by the formula:
a resin (B2) which is a copolymer containing 6 to 77% by mass of (meth)acrylic acid ester structural units, 15 to 71% by mass of styrene structural units, and 8 to 23% by mass of unsaturated dicarboxylic acid structural units;
The following formula (5):
a resin (B3) which is a polymer containing a structural unit (c) represented by the following formula:
a resin (B4) which is a copolymer containing 5 to 20% by mass of styrene structural units, 60 to 90% by mass of (meth)acrylic acid ester structural units, and 5 to 20% by mass of N-substituted maleimide structural units;
The following formula (7):
Resin (B5) is a polymer containing a structural unit (e) represented by the formula: and 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 units.
The molding laminate resin sheet according to any one of claims 1 to 4, comprising at least one selected from the group consisting of: The resin (B3) is represented by the following formula (6):
6. The moldable laminate resin sheet according to claim 5, which is a copolymer further comprising a structural unit (d) represented by the following formula: The moldable laminate resin sheet according to any one of claims 1 to 6, wherein the content of the high-hardness resin is 70 to 100% by mass relative to the total mass of the high-hardness resin layer. The moldable laminate resin sheet according to any one of claims 1 to 7, wherein the total thickness of the base layer and the high-hardness resin layer is 0.5 to 3.5 mm. The moldable laminate resin sheet according to any one of claims 1 to 8, wherein the thickness of the base material layer accounts for 75% to 99% of the total thickness of the base material layer and the high-hardness resin layer. The moldable laminate resin sheet according to any one of claims 1 to 9, wherein the viscosity of the hard coating composition is 400 cps or less at 25°C. The moldable laminate resin sheet according to any one of claims 1 to 10, wherein the pencil hardness of the surface of the hard coat layer is 2H or more. A molded product molded using the moldable laminate resin sheet described in any one of claims 1 to 11.