TWI552869B - Transparent resin-laminated plate - Google Patents

Description

Transparent resin laminate

The present invention relates to a transparent resin laminated board which has high antireflection ability and is excellent in scratch resistance, particularly surface hardness.

Conventionally, on the front panel of a display device such as a CRT, an LCD, or a plasma display, an antireflection film is widely used in order to prevent reflection of a surface and to easily view a screen.

On the plastic substrate, a transparent resin laminated plate having an antireflection ability in which a multilayer film is formed is also known. For example, it is known to sequentially laminate a high refractive index layer and an antireflection layer on a light transmissive plastic substrate. The coating layer is a transparent resin laminated plate excellent in abrasion resistance, scratch resistance, adhesion, and light transmittance (Patent Document 1).

Recently, electronic devices such as mobile phones and digital cameras have made remarkable progress as display devices, and are equipped with displays such as small liquid crystals or organic ELs. On the display, a transparent resin laminated board is usually mounted for the purpose of protection, and the transparent resin laminated board has various characteristics as shown below. For example, it is necessary to ensure high visibility, transparency, and anti-reflection ability. From the viewpoint of mechanical strength, it is necessary to have impact resistance, scratch resistance, and high hardness. Further, in order to prevent adverse effects on the machine due to adhesion of dust or electrification, anti-charge capability is also necessary.

Among the above various characteristics, the characteristics of the punching resistance, the scratch resistance, and the high hardness relating to the mechanical strength may not necessarily coexist. For example, an article having high punching resistance and being easily broken may have insufficient surface hardness or scratch resistance. It is easy to have problems with scars. Under such circumstances, development of a transparent resin laminated plate having high hardness and scratch resistance which is excellent in impact resistance has been carried out (Patent Documents 2 and 3). However, in the existing hardness technique, in the pencil hardness test, the surface hardness of only "4H without scratches" is achieved. On the other hand, mobile terminal devices such as mobile phones, smart (functional) mobile phones, and tablet computers have the possibility of being subjected to harsh environments such as dropping, trampling, and friction, and have higher surface hardness, and , transparent resin with excellent anti-reflection ability Laminates are necessary.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. Hei 9-288202

Patent Document 2: Japanese Special Open 2006-35778

Patent Document 3: Japanese Special Opening 2007-216525

In order to solve the above problems, an object of the present invention is to provide a transparent resin laminated board which is excellent in impact resistance and antireflection ability and excellent in scratch resistance and surface hardness.

The inventors of the present invention have found that a plurality of hard coat layers are provided between the resin substrate and the antireflection layer, and the substrate is placed on the substrate by performing various investigations on maintaining high antireflection ability and improving the above physical properties. The hard coat layer on the side contains a specific cerium oxide sol, and the surface hardness of "7H without scratches" is exhibited in the pencil hardness test, and other characteristics are also satisfied, and the invention of the present application is completed.

That is, according to the present invention, there is provided a transparent resin laminated board in which a hard coat layer (B) is laminated on a transparent resin substrate (A), and an antireflection layer (C) is laminated on the hard coat layer (B). a transparent resin laminated plate; the hard coat layer (B) is composed of a hard coat layer I (B1) on the side of the transparent resin substrate and a hard coat layer II (B2) on the side of the antireflection layer; I(B1) has a layer thickness of 5 to 20 μm and is composed of a polyfunctional urethane acrylate having 6 or more (meth) acrylonitrile groups in (a) one molecule, and 100 parts by mass of the polyfunctional urethane acrylate, which comprises a hardened composition of (b) a surface-treated cerium oxide sol of 40 to 200 parts by mass; The hard coat layer II (B2) has a layer thickness of 1 to 10 μm and is composed of a polyfunctional urethane acrylate having 6 or more (meth) acrylonitrile groups in (a) one molecule, and 100 parts by mass of a polyfunctional urethane acrylate containing (c) 1 to 50 parts by mass of a cerium oxide sol having an average particle diameter of 5 to 30 nm and a refractive index of 1.44 to 1.50, (d) a decane coupling compound or 1 to 30 parts by mass of the hydrolyzate, and (e) 0.1 to 3.0 parts by mass of the metal chelate compound, which is composed of a hardened body; the antireflection layer (C) has a refractive index of less than 1.50 and a thickness of 50 a low refractive index layer (C1) of ~200 nm; the low refractive index layer (C1) comprising (f) a cerium oxide sol having an average particle diameter of 5 to 150 nm and a refractive index of 1.44 or less, and (d) a decane coupling compound Or a hydrolyzate thereof, and (e) a hardened composition of a metal chelate compound, and blended with 10 to 50% by mass of (f) cerium oxide sol, (d) decane coupling compound Or the blend ratio of the hydrolyzate to the (e) metal chelate compound is 60 to 99% by mass: 40 to 1% by mass.

In the invention of the above transparent resin laminated board,

(1) The antireflection layer (C) is composed of the low refractive index layer (C1) and two layers of the refractive index layer (C2) located on the transparent resin substrate side, and the medium refractive index layer (C2) is refracted The rate is less than 1.50 and not 1.75, and the thickness is 50 to 200 nm.

(2) an antireflection layer (C), the low refractive index layer (C1), the medium refractive index layer (C2), and a high refractive index layer disposed between the low refractive index layer and the medium refractive index layer (C3) consisting of three layers, the high refractive index layer (C3) having a refractive index of 1.60 or more and less than 2.00, a thickness of 50 to 200 nm, and a high refractive index layer (C3) having a refractive index higher than that of the medium refractive index layer (C2) The refractive index is large.

(3) The surface treatment of the cerium oxide sol is preferably a (meth) acrylonitrile-modified cerium oxide sol or a vinyl-modified cerium oxide sol.

The transparent resin laminated plate of the present invention has high antireflection ability and excellent mechanical strength such as scratch resistance or hardness, and in particular, the surface hardness can reach "7H without scars". Therefore, it is not only a general display device, but also can be suitably used as a front panel of a device having a high hardness requirement such as a mobile phone, a smart (functional) mobile phone, or a tablet computer.

[Formation of the Invention]

The transparent resin laminated plate of the present invention has a basic structure in which a transparent resin substrate (A), a hard coat layer (B), and an antireflection layer (C) are laminated in this order. Further, the layers (B and C) are characterized by the specific structure, physical properties, and composition described above.

[Transparent resin substrate]

The transparent resin substrate is not particularly limited as long as it is a transparent resin which is excellent in punching strength and does not cause an obstacle to visibility. From the viewpoint of transparency and impact strength, a substrate composed of an aromatic polycarbonate resin or a polymethyl methacrylate resin is preferable. A laminated substrate of an aromatic polycarbonate resin and a polymethyl methacrylate resin may also be used. The thickness of the substrate is appropriately selected and designed from the required transparency or impact strength, and is usually selected from the range of 0.2 to 2.0 mm.

[hard coating (B)]

A hard coat layer (B) is laminated on the transparent resin substrate, and the layer (B) is composed of a hard coat layer I (B1) and a hard coat layer II (B2). The hard coat layer I (B1) and the hard coat layer II (B2) are such that the hard coat layer I (B1) is on the substrate side and the antireflection layer (C) described later is laminated on the hard coat layer II (BB2).

[hard coating I (B1)]

The hard coat layer I (B1) is a layer mainly contributing hardness, and has a film thickness of 5 to 20 μm, preferably 10 to 20 μm. When the thickness is less than 5 μm, the hardness is insufficient, and when it exceeds 20 μm, the appearance is poor or the workability is difficult.

This layer is a polyfunctional urethane acrylate (hereinafter, also referred to as polyfunctional urethane acrylate) having 6 or more (meth) acrylonitrile groups in one molecule (a). And containing 100 parts by mass relative to the polyfunctional urethane acrylate (b) A layer obtained by curing a curable composition (hereinafter referred to as a B1 composition) in which 40 to 200 parts by mass of the cerium oxide sol is surface-treated.

<(a) Polyfunctional urethane acrylate>

The polyfunctional urethane acrylate is a polymerizable compound obtained by addition polymerization of a diisocyanate compound and a (meth) acrylate compound having a plurality of hydroxyl groups, and in particular, it is necessary to contain 6 or more ( Methyl) acrylonitrile. By using the polyfunctional urethane acrylate, a layer having a high surface hardness and a dense layer can be formed. A compound having less than 6 (meth)acrylonitrile groups has insufficient surface hardness and lacks scratch resistance.

The diisocyanate compound which is a raw material for the addition polymerization reaction may, for example, be an aromatic diisocyanate such as tolyl diisocyanate or diphenylmethane diisocyanate; 1,6-hexamethylene diisocyanate or 1, An aliphatic diisocyanate such as 3-bis(methyl isocyanate)cyclohexane. The (meth) acrylate compound which is the raw material of the other side may, for example, be trimethylolpropane (meth) acrylate or pentaerythritol (meth) acrylate.

These two raw materials are used in an amount of 6 times by mole or more based on the (meth) acrylonitrile group, and then reacted in a manner known per se to obtain the above-mentioned polyfunctional urethane acrylate.

<(b) Surface treatment of cerium oxide sol>

The surface-treated cerium oxide sol is a component which imparts extremely high hardness to the transparent resin substrate of the present invention by being combined with a polyfunctional urethane acrylate. It is important to blend in an amount of 40 to 200 parts by mass based on 100 parts by mass of the above polyfunctional urethane acrylate.

The surface-treated cerium oxide sol is a surface of the cerium oxide particles known per se, and is 3-methylpropenyloxypropyltriethoxydecane, 3-propenyloxypropyltrimethoxydecane, or the like. a (meth) propylene fluorenyl modified cerium oxide sol treated with a decane coupling agent having an alkoxy fluorenyl group at the end, or a vinyl triethoxy decane, vinyl methyl dimethoxy decane or the like having ethylene Ethylene treated with a decane coupling agent The base is modified with a cerium oxide sol.

The method of the surface treatment is not particularly limited, and a conventionally known method can be employed. For example, the decane coupling agent is dissolved in an organic solvent such as methanol, toluene, methyl isobutyl ketone or methyl isobutyl butyl ketone to form a solution, and a cerium oxide sol is introduced into the solution. Heat at about 50~150 °C and stir for about 5~30 hours to react.

<B1 composition>

The B1 composition is a composition of the hard coat layer I by hardening, and the surface-treated cerium oxide sol content is 40 to 200 parts by mass based on 100 parts by mass of the polyfunctional urethane acrylate. In the composition of B1, any additive for the purpose of viscosity adjustment or easy coating property can be added within the range which does not impair the purpose. In particular, in order to harden the composition on the transparent resin substrate to form the hard coat layer I (B1), usually, a thermal polymerization initiator or a photopolymerization initiator is added as a catalyst, usually as a solid in the composition. The total amount of the ingredients is used as a standard, and 0.01 to 20% by mass is added. This polymerization initiator does not have an essential influence on various characteristics of the hard coat layer I obtained by hardening the B1 composition.

As the polymerization initiator, 2,2'-dimethoxy-1,2-diphenylethyl-1 which acts by ultraviolet rays or electron beams from the viewpoint of preventing deformation of the transparent resin substrate due to heat A photopolymerization initiator such as a ketone, 1-hydroxy-cyclohexyl-phenyl-ketone, camphorquinone, Benzil or the like is suitable.

<Formation of Hard Coating I>

The respective components (a) and (b) and the optional components are dissolved in the following solvent to prepare a solution of the B1 composition, and after applying the solution to the transparent resin substrate, the solvent is applied at 50 ° C or higher. It is dried and then hardened by ultraviolet irradiation to form a hard coat layer I. The thickness of this layer is 5 to 20 μm, and is preferably set in the range of 10 to 20 μm.

Solvent to be used: an alcohol solvent such as ethanol or (iso)propanol; an aromatic solvent such as toluene or xylene; an acetate solvent such as (iso)butyl acetate; and methyl ethyl ketone; A ketone solvent such as (MEK) or methyl isobutyl ketone (MlBK) is suitable. These solvents are removed by evaporation when the hard coat layer I is formed.

Each of the above components constituting the composition of B1 is usually mixed with a solvent in an arbitrary order at room temperature, and stirred to form a solution.

The method of applying the solution to the transparent resin substrate is not particularly limited, and a dip coating method, a roll coating method, a die coating method, a shower coating method, a spray coating method, or the like may be employed, but from the viewpoint of appearance quality or film thickness control. The dip coating method is suitable.

[hard coating II (B2)]

The hard coat layer II (B2) is a layer mainly imparting adhesion to the antireflection layer laminated thereon, and has a film thickness of 1 to 10 μm. When the thickness is less than 1 μm, the adhesion is insufficient, and when it exceeds 10 μm, it is difficult to maintain the appearance.

The layer contains (a) a polyfunctional urethane acrylate, and (c) an average particle diameter of 5 to 30 nm and a refractive index relative to 100 parts by mass of the polyfunctional urethane acrylate. It is 1 to 50 parts by mass of 1.44 to 1.50 of cerium oxide sol, (d) a decane coupling compound or a hydrolyzate of 1 to 30 parts by mass, and (e) a metal chelating compound of 0.1 to 3.0 parts by mass. A layer composed of a cured body of a composition (hereinafter, also referred to as a B2 composition).

As the (a) polyfunctional urethane acrylate, the same as those enumerated in the hard coat layer I can be used.

<(c) cerium oxide sol>

The cerium oxide sol contained in the hard coat layer II (B2) is a particle which contributes to the improvement of scratch resistance, and has an average particle diameter of 5 to 30 nm and a refractive index of 1.44 to 1.50. When the average particle diameter is outside the above range, the crack resistance is deteriorated.

The cerium oxide sol is composed of a single particle and has a tight interior and a non-hollow particle having no space inside, and has a density of usually 1.9 g/cm ³ or more. Since the cerium oxide sol itself is known and sold commercially, it is preferable to use a commercially available product satisfying the above average particle diameter and refractive index. The cerium oxide sol is usually supplied in a state of being dispersed in a solvent, and this solvent is inevitably mixed into the hardenable composition solution for forming the hard coat layer II, and behaves in the same manner as other solvents.

<(d) decane coupling compound or its hydrolyzate>

The decane coupling compound or a hydrolyzate thereof is hydrolyzed by itself to form a dense coating film of phthalic acid.

As the decane coupling compound, a known one can be used without limitation. For example, γ-methacryloxypropyltrimethoxydecane, γ-methylpropenyloxypropylmethyldimethoxydecane, 3-propenyloxypropyltrimethoxy group Decane, vinyltrimethoxydecane, vinyltriethoxydecane, p-styryltrimethoxydecane, γ-glycidoxypropyltrimethoxydecane, 2-(3,4 epoxycyclohexyl Ethyltrimethoxydecane, γ-glycidoxypropylmethyldimethoxydecane, 3-glycidoxypropylmethyldiethoxydecane, γ-aminopropyltrimethoxy Decane, 3-aminopropyltriethoxydecane, N-2 (aminoethyl) 3-aminopropylmethyldimethoxydecane, N-2 (aminoethyl) 3-aminopropyltriethoxy Baseline, N-2 (aminoethyl) 3-aminopropyltriethoxydecane, 3-mercaptopropylmethyldimethoxydecane, 3-mercaptopropyltrimethoxydecane, 3-isocyanatepropyl Triethoxy decane and the like.

The decane coupling compound is suitably hydrolyzed to a decomposition product by a thin acid or the like for the purpose of improving the solubility in water or a solvent depending on the type thereof. The method of pre-hydrolysis is not particularly limited, and is generally a method of hydrolyzing a part thereof using an acid catalyst such as acetic acid.

<(e) Metal Chelate Compound>

The metal chelate compound is contained in order to increase the compactness or strength of the layer or even to make the hardness higher. The metal chelating compound is a compound in which a chelating agent represented by a bidentate ligand is a metal such as titanium, zirconium or aluminum.

Specifically, it can be cited as: triethoxy. Single (acetylpyruvate) titanium, diethoxy. Bis(acetylpyruvate) titanium, monoethoxy. Reference (acetyl acetonate) titanium, bismuth (acetyl acetonate) titanium, triethoxy. Single (ethyl acetonitrile) titanium, diethoxy. Bis(ethylacetamidineacetic acid) titanium, monoethoxy. Reference (ethyl ethyl acetonitrile) titanium, single (acetyl acetonate) a titanium chelate compound such as titanium (ethyl acetoacetate), bis(ethyl acetonate) bis(ethyl acetonitrile) titanium, ginseng (acetyl acetonate) mono(ethyl acetonitrile) titanium; Triethoxy. Single (acetyl acetonate) zirconium, diethoxy. Bis(acetylpyruvyl)zirconium, monoethoxy. Zirconium (acetyl acetonate) zirconium, cerium (acetyl acetonate) zirconium, triethoxy. Mono(ethylacetamidineacetic acid) zirconium, diethoxy. Bis(ethylacetamidineacetic acid) zirconium, monoethoxy. Zirconium (ethyl acetoacetate) zirconium, cerium (ethyl acetoacetate) zirconium, mono (acetyl acetonate) ginseng (ethyl acetoacetate) zirconium, bis (acetyl acetonate) bis (ethyl acetamidine) Zirconium chelate compound such as zirconium acetate, zirconium (acetylacetonate) mono(ethylacetonitrile acetate) zirconium; diethoxy. Single (acetyl acetonate) aluminum, monoethoxy, bis(acetyl acetonate) aluminum, diisopropoxy. Single (acetylpyruvate) aluminum, monoethoxy. Bis(ethylacetamidineacetic acid) aluminum, diethoxy. An aluminum chelate compound such as mono(ethylacetonitrile)aluminum.

<B2 composition>

The B2 composition is a curable composition containing the components (a), (c), (d), and (e) as essential components, and is blended at a specific ratio described below.

(c) The cerium oxide sol is blended in an amount of 1 to 50 parts by mass based on 100 parts by mass of the polyfunctional urethane acrylate. When the amount is less than 1 part by mass, the scratch resistance is not exhibited, and if it exceeds 50 parts by mass, the film adhesion is deteriorated.

(d) The decane coupling compound or the hydrolyzate thereof is blended in an amount of 1 to 30 parts by mass based on 100 parts by mass of the polyfunctional urethane acrylate. When the amount is less than 1 part by mass, the film adhesion is deteriorated, and if it exceeds 50 parts by mass, the scratch resistance is deteriorated.

(e) The metal chelate compound is blended in an amount of 0.1 to 3.0 parts by mass based on 100 parts by mass of the polyfunctional urethane acrylate. If it is outside this range, the adhesion with the antireflection layer C formed on the hard coat film II may deteriorate.

The B2 composition is the same as the B1 composition, and any optional component may be added. Usually, a polymerization initiator is added for the purpose of promoting hardening, and a solvent is used for the purpose of coating. The preparation method of the B2 composition is also carried out in accordance with the composition of B1.

<Formation of Hard Coating II>

Hard coat layer II, directly laminated on a transparent resin substrate, laminated with a hard coat layer I On top, a hard coat layer composed of two layers is formed. The formation of the hard coat layer II is carried out in the same manner as in the formation of the hard coat layer I, and the like. The thickness of the formed layer is set in the range of 1 to 10 μm.

[Anti-reflection layer (C)]

The transparent resin laminated plate of the present invention is obtained by directly laminating an antireflection layer (C) on a hard coat layer laminated on the transparent resin substrate. The antireflection layer (C) is composed of a low refractive index layer (C1) having a refractive index of less than 1.50 and a thickness of 50 to 200 nm. Further, as will be described later, when the antireflection layer (C) is composed of a plurality of antireflection layers, the low refractive index layer is an antireflection layer of the outermost layer (viewing side).

The low refractive index layer (C1) does not exhibit sufficient antireflection function if its refractive index is 1.50 or more. Moreover, if the thickness is outside the range of 50 to 200 nm, the antireflection function cannot be exhibited.

The low refractive index layer (C1) is composed of (f) a cerium oxide sol having an average particle diameter of 5 to 150 nm, a refractive index of 1.44 or less, (d) a decane coupling compound or a hydrolyzate thereof, and (e) a layer composed of a hardened body of a curable composition (C1 composition) of a metal chelate compound, and blended with 10 to 50% by mass of (f) cerium oxide sol, (d) a decane coupling compound or The blending ratio of the hydrolyzate to the (e) metal chelate compound is 60 to 99% by mass: 40 to 1% by mass.

<(f) cerium oxide sol>

The cerium oxide sol contained in the low refractive index layer (C1) is a particle which controls the refractive index of the layer, and has an average particle diameter of 5 to 150 nm and a refractive index of 1.44 or less. When the average particle diameter is outside the above range, the reflection performance is lowered and the turbidity is increased. If the refractive index exceeds 1.44, the reflection performance is low.

The cerium oxide sol may be selected from commercially available products to satisfy the above average particle diameter and refractive index. In particular, hollow cerium oxide sol particles are suitable from the viewpoint of antireflection effect. The cerium oxide sol is also provided in a state of being generally dispersed in a solvent, and this solvent behaves in the same manner as in the case of the above (c) cerium oxide sol.

(d) a decane coupling compound or a hydrolyzate thereof and (e) a metal chelate compound can be used in the same manner as described above.

<C1 composition>

The composition of C1 is a curable composition containing the components (f), (d), and (e) as essential components, and is blended at a specific ratio described below.

(f) The cerium oxide sol must be contained in the layer in an amount of 10 to 50% by mass. If it is less than 10% by mass, a sufficient antireflection effect cannot be expected. When it exceeds 50% by mass, the scratch resistance and the adhesion are low.

(d) The blend ratio of the decane coupling compound or the hydrolyzate thereof and the (e) metal chelate compound is 60 to 99% by mass: 40 to 1% by mass. (e) When the blending ratio of the metal chelate compound is more than 40% by mass, it is not preferable because the film becomes brittle or the chelate compound precipitates. If it is less than 1% by mass, the effect cannot be exhibited.

The C2 composition is the same as the B1 or B2 composition, and any optional component may be added. Usually, a solvent is used for the purpose of coating. The preparation method of the C2 composition is also carried out in accordance with the composition of B1 or B2.

<Formation of Low Refractive Index Layer (C1)>

The low refractive index layer is a hard coat layer laminated on a transparent resin substrate, and in detail, is laminated on the hard coat layer II. In the formation of the low refractive index layer, a solution of the C1 composition is applied onto the hard coat layer 2 which is a hardened body in accordance with the formation of the hard coat layer, and then dried, and then heated at 70 to 120 ° C to be cured. The thickness of this layer is set in the range of 50 to 200 nm from the viewpoint of antireflection performance.

Further, in the case where the antireflection layer is composed of two layers of a medium refractive index layer and a low refractive index layer which are later described, on the hard coat layer II, a medium refractive index layer is first formed, and then a low refractive index layer is formed on the layer. . Further, in the case where the antireflection layer is composed of three layers of a medium refractive index layer, a high refractive index layer, and a low refractive index layer, the medium refractive index layer is first formed on the hard coating layer II, and then the layer is formed. A high refractive index layer is formed thereon, and a low refractive index layer is further formed thereon.

[Medium refractive index layer (C2)]

In order to further improve the antireflection effect, the transparent resin laminated plate of the present invention is preferably a two-layer structure in which a medium refractive index layer is laminated on the substrate surface side of the low refractive index layer.

The medium refractive index layer has a refractive index of 1.50 or more and less than 1.75, and a layer having a thickness of 50 to 200 nm is suitable.

The medium refractive index layer is represented by, in order to contain 20 to 80 parts by mass of the (d) decane coupling compound or its hydrolyzate, and (e) 0.1 to 2 parts by mass of the metal chelate compound, plus (g) The curable composition of 20 to 80 parts by mass of the metal oxide particles having a refractive index of 1.70 or more and 2.80 or less (100 parts by mass of the total amount of (d), (e), and (g)) is cured.

Further, the medium refractive index layer may contain a thermosetting resin as a binder. Examples of the thermosetting resin include phenol-formaldehyde resin, decane-modified phenol resin, furan-formaldehyde resin, xylene-formaldehyde resin, ketone-formaldehyde resin, urea-formaldehyde resin, melamine-formaldehyde resin, and alkyd. Resin, unsaturated polyester resin, (decane-modified) epoxy resin, bismaleimide resin, triallyl cyanurate resin, acrylic resin, (decane-modified) acrylic resin, epoxy resin, A urethane resin or the like. These resins may be used singly or in combination of two or more. The above thermosetting resin used as a binder has an advantage of being resistant to oxidation due to photoactivity.

<(g) Metal oxide particles>

(g) The metal oxide particles are contained for the purpose of satisfying the refractive index of the medium refractive index layer of 1.50 or more and not up to 1.75. Typically, the average particle diameter is 10 to 100 nm, and the refractive index is 1.70 or more and 2.80. The following metal oxide particles.

As the metal oxide particles, zirconium oxide particles (refractive index = 2.40); composite zirconium metal oxide particles obtained by oxidizing zirconium oxide and other oxides such as cerium oxide at a molecular level to adjust the refractive index; Refractive index = 2.71); composite titanium oxide particles in which titanium oxide and other oxides such as cerium oxide or zirconium oxide are combined in a molecular layer to adjust the refractive index; cerium oxide particles (refractive index = 1.55). The metal oxide particles are selected from these metal oxide particles or appropriately combined to adjust the layer having the desired refractive index as described above. Such particles are known per se and are sold.

<Formation of medium refractive index layer (C2)>

The medium refractive index layer is a hard coat layer laminated on a transparent resin substrate, specifically, laminated on the hard coat layer II. The formation of the medium refractive index layer is carried out in the same manner as the formation of the low refractive index layer, and the thickness of the layer is set in the range of 50 to 200 nm from the viewpoint of antireflection performance.

[High refractive index layer (C3)]

The transparent resin laminated plate of the present invention has three layers of a high refractive index layer (C3) laminated between the low refractive index layer (C1) and the medium refractive index layer (C2) in order to exhibit an extremely high antireflection effect. The structure is particularly ideal.

The high refractive index layer is preferably a layer having a refractive index of 1.60 or more and less than 2.00 and a thickness of 50 to 200 nm. Moreover, the refractive index of the high refractive index layer must be higher than the refractive index of the medium refractive index layer.

The high refractive index layer is represented by, for example, 10 to 50 parts by mass of the (d) decane coupling compound or the hydrolyzate thereof, and (g) 50 to 90 parts by mass of the metal oxide particles {(d) and The total amount of (g) is formed by hardening a hardening composition of 100 parts by mass}. (g) The metal oxide particles are selected from the metal oxide particles disclosed above, or are used in combination such that the refractive index of the high refractive index layer is 1.60 or more and less than 2.00.

Further, similarly to the medium refractive index layer, a thermosetting resin may be contained as a binder.

<Formation of High Refractive Index Layer (C3)>

The high refractive index layer is laminated on the intermediate refractive index layer laminated on the hard coat layer, and then the low refractive index layer is laminated on the high refractive index layer to have a three-layer structure. The formation of the high refractive index layer is carried out in the same manner as the formation of the low refractive index layer, and the thickness of the layer is set in the range of 50 to 200 nm from the viewpoint of antireflection performance.

The transparent resin laminated plate of the present invention is not limited to the above-described layer constitution. For example, a protective film layer may be provided for the purpose of protection of the antireflection layer. As such a protective film The layer may be an organic polyoxyalkylene-based material or a fluororesin-based coating which imparts abrasion resistance and scratch resistance.

Further, on the back side of the transparent resin laminated plate, an adhesive layer made of an acrylic, rubber or polyoxygen-based adhesive may be provided. Further, in the transparent resin laminate of the present invention, the hard coat layer (B) and the antireflection layer (C) may be laminated on both the front surface and the back surface of the transparent resin substrate.

Example

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to the examples. Further, not all of the features described in the embodiments are essential to the means for solving the invention.

The various components and abbreviations used in the following examples and comparative examples, and test methods, are as follows.

(a) Polyfunctional urethane acrylate

A-1; aliphatic organic isocyanate 6-functional acrylate

A-2; aromatic organic isocyanate 6-functional acrylate

(b) Surface treatment of cerium oxide sol

B-1; acrylate-modified cerium oxide sol (treated with 3-propenyloxypropyltrimethoxydecane) average particle diameter: 20 nm, MIBK dispersion, solid content: 30% by weight

B-2; vinyl modified cerium oxide sol (treated with vinyl trimethoxy decane) average particle size: 20 nm, MEK dispersion, solid content: 30% by weight

(c) cerium oxide sol

C-1; average particle diameter: 10 nm, refractive index: 1.46, IPA dispersion, solid content: 20% by weight

C-2; average particle diameter: 80 nm, refractive index: 1.46, IPA dispersion, solid content: 30% by weight

(d) a decane coupling compound or a hydrolyzate thereof

D-1; γ-glycidoxypropyltrimethoxydecane

D-2; 3-propenyloxypropyltrimethoxydecane

D-3; 2-(3,4-epoxycyclohexyl)ethyltrimethoxydecane

(e) Metal chelate compound

E-1; dibutoxy bis(ethylacetamidineacetic acid) zirconium

E-2; alkyl acetamidine acetate diisopropylate

E-3; acetylacetate aluminum pyruvate

E-4; tetraethylguanidinium pyruvate

(f) cerium oxide sol

F-1; average particle diameter: 50 nm, hollow cerium oxide sol, refractive index: 1.30, IPA dispersion, solid content: 20% by weight

F-2; average particle diameter: 80 nm, cerium oxide sol, refractive index: 1.46, IPA dispersion, solid content: 20% by weight

F-3; average particle diameter: 10 nm, cerium oxide sol, refractive index: 1.46, IPA dispersion, solid content: 20% by weight

(g) metal oxide particles

G-1; average particle diameter: 50 nm, zirconia sol, refractive index: 2.40, PGM dispersion, solid content: 55 wt%

G-2; average particle diameter: 20 nm, titania sol, refractive index: 2.71, MIBK dispersion, solid content: 20% by weight

(h) other

H-1; IPA (isopropyl alcohol)

H-2; MIBK (methyl isobutyl ketone)

H-3; toluene

H-4; photopolymerization initiator (1-hydroxy-cyclohexyl-phenyl-one)

H-5; 0.05N acetic acid

H-6; alkoxy-modified decane modified epoxy resin

[Reflective test]

The reflectance at the lowest point (surface of the transparent resin laminate) was measured at a scanning speed of 1000 nm/min and a wavelength of 380 to 780 nm using a "V-550" tester manufactured by JASCO Corporation. The smaller the value, the more excellent the antireflection ability.

[Scratch resistance test]

A test piece was placed in a friction tester, and a steel ball was reciprocated 100 times between 40 mm under a load of 2 kg/cm ² on SteelWool #0000 ("BONSTER" of Japan SteelWool Co., Ltd.), and the manner of occurrence of the flaw and the number of the flaws were measured and evaluated. The evaluation criteria are as follows. Light transmission means light transmitted through a transparent resin laminated plate, and reflected light means light reflected on the surface of the laminated plate.

"◎": No flaws were observed regardless of whether the transmitted light or the reflected light was observed.

"○": Several flaws were observed when observing the transmitted light, but not reflected by the reflected light.

"△": It is confirmed that there are several flaws regardless of whether the transmitted light or the reflected light is observed.

"X": It is confirmed that there are more than ten flaws regardless of whether the transmitted light or the reflected light is observed.

[Hardness test]

The hardness was measured with a pencil ("Uni" manufactured by Mitsubishi Pencil Co., Ltd.) using a hardness tester "C-2210" manufactured by Jiguang Precision Co., Ltd. The hardness is expressed by pencil hardness, and the higher the hardness, the more excellent the scratch resistance. Further, the pencil hardness of 7H means that the pencil of 7H does not cause scratches, but the hardness of the case of the flaw can be confirmed by the pencil of 8H.

Example 1

On the PMMA side of a laminated resin substrate (having a thickness of a PC layer of 0.93 mm and a thickness of a PMMA layer of 0.07 mm) of an aromatic polycarbonate resin (PC) having a thickness of 1 mm and a polymethyl methacrylate resin (PMMA), the following The method forms a hard coat layer and forms an antireflection layer thereon.

[Composition of a solution for forming a hard coat layer I]

. A-1;300g

. B-1; 450g

. H-1;235g

. H-4; 15g

[Composition of solution for forming hard coat II]

. A-1;175g

. C-1; 300g

. D-1; 20g

. E-3; 1.5g

. H-1; 198.1g

. H-2;274.6g

. H-3; 17.5g

. H-4; 8.8g

. H-5; 4.5g

[Composition of solution for forming anti-reflective layer]

. F-1; 45g

. D-1; 13g

. E-3;3g

. H-1; 935g

. H-5;4g

First, the laminated resin substrate was dip-coated with a solution for forming a hard coat layer I having the above composition, dried at 60 ° C for 5 minutes, and cured by UV to form a hard coat layer I having a thickness of 12 μm. Next, the solution for forming a hard coat layer II having the above composition was dip-coated with the substrate having the hard coat layer I, dried at 60 ° C for 5 minutes, and cured by UV to form a hard coat layer II having a thickness of 3 μm. Further, the substrate having the hard coat layer was dip-coated with a solution for forming an antireflection layer, and heat-treated at 80 ° C for 20 minutes to form an antireflection layer (low refractive index layer) having a thickness of 100 nm. Thereafter, the fluorine-based antifouling agent was subjected to surface coating by dip coating, and the film was cured by heat treatment at 100 ° C for 120 minutes.

The reflectance, hardness, and scratch resistance of the obtained transparent resin laminated plate were measured and evaluated in accordance with the above test methods. The results are shown in Table 1.

Example 2~6

A transparent resin laminated plate was produced in the same manner as in Example 1 except that the hard coat layer I forming solution, the hard coat layer II forming solution, and the antireflection layer forming solution shown in Table 1 were used. The measurement was carried out. The results are shown in Tables 1 and 2.

[Table 1]

Comparative example 1~5

A transparent resin laminated plate was produced in the same manner as in Example 1 except that the hard coat layer I forming solution, the hard coat layer II forming solution, and the antireflection layer forming solution shown in Table 2 were used. The measurement was carried out. The results are shown in Table 3.

According to the comparison between Example 1 and Comparative Example 1, it can be understood that if the content of the (A) surface-treated cerium oxide sol is less than 50 mass relative to 100 parts by mass of the polyfunctional urethane acrylate in the hard coat layer I The hardness performance will deteriorate. Further, according to Comparative Example 2, when the film thickness of the hard coat layer I was not 5 μm or more, the hardness performance was deteriorated and the scratch resistance was extremely deteriorated. Further, according to Comparative Example 3, in the case where the hard coat layer II does not contain a decane coupling agent, hardness properties and scratch resistance are not sufficient. According to Comparative Example 4, in the case where the hard coat layer II did not contain the cerium oxide sol, the scratch resistance was insufficient. According to Comparative Example 5, in the case where the hard coat layer II was not present, the hardness performance was insufficient and the scratch resistance was extremely deteriorated.

Examples 7-9

The solution for forming a low refractive index layer, the solution for forming a medium refractive index layer, and the solution for forming a high refractive index layer as required in the following Table 3 were used to form a layer of two or three layers in the following manner. A transparent resin laminated plate having an antireflection film was evaluated. The results are shown in Table 4.

After the hard coat layer was formed on the laminated resin substrate in the same manner as in Example 1, the substrate having the hard coat layer was dip-coated in the medium refractive index layer forming solution, and heat-treated at 90 ° C for 30 minutes to form a thickness. A medium refractive index layer of 85 nm. Next, the substrate was dip-coated in a solution for forming a low refractive index layer, and heat-treated at 80 ° C for 20 minutes to form a low refractive index layer having a thickness of 100 nm. However, in Examples 7 and 8, before the formation of the low refractive index layer, that is, after the formation of the medium refractive index layer, the substrate was dip coated on the solution for forming a high refractive index layer, and heat treated at 80 ° C for 20 minutes. A high refractive index layer of 80 nm was formed.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic view showing the cross-sectional structure of a representative antireflection sheet of the present invention.

Claims (4)

A transparent resin laminated plate obtained by laminating a hard coat layer (B) on a transparent resin substrate (A) and laminating an antireflection layer (C) on the hard coat layer (B) The hard coat layer (B) is composed of a hard coat layer I (B1) on the side of the transparent resin substrate and a hard coat layer II (B2) on the side of the antireflection layer; the layer thickness of the hard coat layer I (B1) is 5 to 20 μm, comprising a polyfunctional urethane acrylate having 6 or more (meth) acrylonitrile groups in (a) one molecule, and relative to the polyfunctional urethane ester 100 parts by mass of the acrylate comprises a hardened composition of (b) a surface-treated cerium oxide sol of 40 to 200 parts by mass; and the hard coat layer II (B2) has a layer thickness of 1 to 10 μm and is contained ( a) a polyfunctional urethane acrylate having 6 or more (meth) acrylonitrile groups in one molecule, and (c) average with respect to 100 parts by mass of the polyfunctional urethane acrylate 1 to 50 parts by mass of a cerium oxide sol having a particle diameter of 5 to 30 nm and a refractive index of 1.44 to 1.50, (d) a decane coupling compound or a hydrolyzate thereof of 1 to 30 parts by mass, and (e) a metal chelate compound 0.1 ~3.0 quality A hardened composition of the cured composition; the antireflection layer (C) is composed of a low refractive index layer (C1) having a refractive index of less than 1.50 and a thickness of 50 to 200 nm; the low refractive index layer (C1) is contained (f) a cerium oxide sol having an average particle diameter of 5 to 150 nm, a refractive index of 1.44 or less, (d) a decane coupling compound or a hydrolyzate thereof, and (e) a hardening composition of a metal chelate compound a hardened body composed of 10 to 50% by mass of (f) cerium oxide sol, (d) a decane coupling compound or a mixture ratio of the hydrolyzate thereof and the (e) metal chelating compound is 60 to 99 mass %: 40 to 1% by mass. The transparent resin laminate according to the first aspect of the invention, wherein the antireflection layer (C) is composed of the low refractive index layer (C1) and the second layer of the refractive index layer (C2) located on the side of the transparent resin substrate. The medium refractive index layer (C2) has a refractive index of 1.50 or more and less than 1.75, and a thickness of 50 to 200 nm. A transparent resin laminated board according to the second aspect of the patent application, wherein the antireflection layer (C) consisting of the low refractive index layer (C1), the medium refractive index layer (C2), and the high refractive index layer (C3) disposed between the low refractive index layer and the medium refractive index layer The high refractive index layer (C3) has a refractive index of 1.60 or more and less than 2.00 and a thickness of 50 to 200 nm, and the refractive index of the high refractive index layer (C3) is larger than that of the intermediate refractive index layer (C2). A transparent resin laminated plate according to claim 1 or 2, wherein the surface-treated cerium oxide sol is a (meth)acryl fluorenyl modified cerium oxide sol or a vinyl modified cerium oxide sol.