JP2022115882A - Hard coat film, and hard coat film with anti-scratching layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hard coat film high in hardness, and excellent in repeatedly bending resistance, and a hard coat film with an anti-scratching layer excellent in anti-scratching property.

SOLUTION: A hard coat film has a hard coat layer on at least one side surface of a support medium, where when a pushing-in elastic modulus when pushing by 10% of a thickness of the hard coat layer from a surface opposite to a support medium side of the hard coat layer is E₁₀, and a pushing-in elastic modulus when pushing by 2% of a thickness of the hard coat layer is E₂, the following formulae (1), (2), and (3) are satisfied, and the number of times until crack or break is generated is 500,000 times or more in a flex resistance test done by bending around a curvature radius of 1.0 mm with the hard coat layer inside. E₁₀-E₂≥2 GPa (1). E₁₀≥8 GPa (2). E₂≤8 GPa (3).

SELECTED DRAWING: None

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to a hard coat film and a hard coat film with a scratch resistant layer.

Thin and hard glass such as chemically strengthened glass is often used on the surface of mobile displays such as smartphones and tablets to withstand touch panel operation and pen input and to protect the display part. On the other hand, although glass is basically hard, it has the problem of being heavy and fragile.
Various proposals have been made because it is believed that a transparent plastic film that is as hard as glass would have the advantage of being light and unbreakable. For example, a film having excellent transparency, surface hardness, and scratch resistance has been proposed by coating the surface of a transparent resin film with a hard coat layer composed of an organic resin and metal oxide particles (Patent Document 1).

In recent years, however, there has been an increasing need for flexible displays, and existing techniques are not suitable for surface protection of displays that have low flexibility and are flexible.
For example, in Patent Document 2, a first hard coat layer containing a cured product of polyfunctional (meth)acrylate and silica fine particles and a cured product of a polyfunctional (meth)acrylate monomer are provided on a substrate film. A hard-coated film for a touch panel has been proposed that is provided with a second hard-coated layer and has somewhat excellent hardness, scratch resistance, and durable folding performance.

Japanese Patent Application Laid-Open No. 2016-01217 Japanese Patent Application Laid-Open No. 2017-33032

However, in Patent Document 2, the bending radius in the endurance folding test is large, and it is difficult to say that repeated bending resistance is sufficient.
An object of the present invention is to provide a hard coat film having high hardness and excellent resistance to repeated bending, and a hard coat film with a scratch resistant layer having excellent scratch resistance.

The present inventors have made intensive studies and found that the above problems can be solved by the following means.
<1>
A hard coat film having a hard coat layer on at least one surface of a support,
In an indentation test in which a load is applied vertically using a diamond knoop indenter from the surface of the hard coat layer opposite to the support side, the indentation when indented by 10% with respect to the thickness of the hard coat layer When the elastic modulus is E ₁₀ and the indentation elastic modulus when pushed 2% with respect to the thickness of the hard coat layer is E ₂ , the following formulas (1), (2) and (3) are satisfied,
the support is selected from triacetyl cellulose film, polymethyl methacrylate film, polyamide film, aramid film, polyimide film, polyamideimide film, polyetherimide film, polyesterimide film, and polyethylene terephthalate film;
A hard coat film, wherein, in a bending resistance test in which the hard coat layer is positioned inside and the bending radius of curvature is 1.0 mm, the number of times until the hard coat film cracks or breaks is 500,000 times or more.
E ₁₀ −E ₂ ≧2 GPa (1)
E ₁₀ ≧8 GPa (2)
E ₂ ≤ 8 GPa (3)
<2>
The hard coat film of <1>, which has a pencil hardness of 4H or more as measured according to JIS K5600-5-4 (1999).
<3>
The hard coat film according to <1> or <2>, wherein the hard coat layer does not contain particles, or if it contains particles, the particles have an average primary particle size of 3 to 100 nm.
<4>
The hard coat film according to any one of <1> to <3>, wherein the hard coat layer does not contain particles, or when the hard coat layer contains particles, the particles are inorganic fine particles.
<5>
A hard coat film with a scratch resistant layer, the hard coat film according to any one of <1> to <4> having a scratch resistant layer on the surface of the hard coat layer opposite to the support side.
Although the present invention relates to the above <1> to <5>, other matters are also described in this specification for reference.
[1]
A hard coat film having a hard coat layer on at least one surface of a support,
The hard coat layer contains a matrix component and inorganic fine particles having an average primary particle size of 3 to 100 nm,
The content of the inorganic fine particles in the hard coat layer is 50% by volume or more and 90% by volume or less,
In an indentation test in which a load is applied vertically using a diamond knoop indenter from the surface of the hard coat layer opposite to the support side, the indentation when indented by 10% with respect to the thickness of the hard coat layer It is characterized by satisfying the following formulas (1), (2), and (3), where E ₁₀ is the elastic modulus and E ₂ is the indentation elastic modulus when pushed 2% with respect to the thickness of the hard coat layer. A hard coat film.
E ₁₀ −E ₂ ≧2 GPa (1)
E ₁₀ ≧8 GPa (2)
E ₂ ≤ 8 GPa (3)
[2]
The hard coat film according to [1], wherein _EM ≤ 1.5 GPa, where _EM is the indentation elastic modulus of the matrix component.
[3]
The matrix component is a cured product of a matrix-forming composition,
The hard coat film of [1] or [2], wherein the matrix-forming composition has a polymerizable functional group equivalent of 250 or more.
[4]
The hard coat film of any one of [1] to [3], wherein the inorganic fine particles are particles modified with a silane coupling agent having two or more polymerizable functional groups in one molecule.
[5]
from [1], wherein the support is selected from triacetylcellulose film, polymethyl methacrylate film, polyamide film, aramid film, polyimide film, polyamideimide film, polyetherimide film, polyesterimide film, and polyethylene terephthalate film The hard coat film of [4].
[6]
A hard coat film with a scratch resistant layer, wherein the hard coat film of [1] to [5] has a scratch resistant layer on the surface of the hard coat layer opposite to the support side.

ADVANTAGE OF THE INVENTION According to this invention, the hard coat film which has high hardness and is excellent in resistance to repeated bending, and the hard coat film with an abrasion-resistant layer which is excellent in abrasion resistance can be provided.

Modes for carrying out the present invention will be described in detail below, but the present invention is not limited to these. In this specification, when numerical values represent physical property values, characteristic values, etc., the description “(numerical value 1) to (numerical value 2)” means “(numerical value 1) or more (numerical value 2) or less”. . Moreover, in this specification, the description “(meth)acrylate” means “at least one of acrylate and methacrylate”. The same applies to "(meth)acrylic acid", "(meth)acryloyl" and the like.

[Hard coat film]
The hard coat film of the present invention is
A hard coat film having a hard coat layer on at least one surface of a support,
The hard coat layer contains a matrix component and inorganic fine particles having an average primary particle size of 3 to 100 nm,
The content of the inorganic fine particles in the hard coat layer is 50% by volume or more and 90% by volume or less,
In an indentation test in which a load is applied vertically using a diamond knoop indenter from the surface of the hard coat layer opposite to the support side, the indentation when indented by 10% with respect to the thickness of the hard coat layer A hard coat that satisfies the following formulas (1), (2), and (3), where E ₁₀ is the elastic modulus, and E ₂ is the indentation elastic modulus when the hard coat layer is pushed in by 2% with respect to the thickness of the hard coat layer. It's a film.
E ₁₀ −E ₂ ≧2 GPa (1)
E ₁₀ ≧8 GPa (2)
E ₂ ≤ 8 GPa (3)

It deforms in the film thickness direction (approximately ₁₀ % of the thickness) due to the stress applied during the pencil hardness test, and the higher the elastic modulus E10 at the time of deformation, the better. The higher the _E10 , the more difficult it is to deform, and the deformation does not reach the brittle fracture region, so the pencil hardness can be increased. On the other hand, since repeated bending repeatedly gives a small amount of strain of about ₂ %, the lower the elastic modulus E2 when pushed in by 2%, the better. It is thought that repeated bending causes minute _cracks inside the film, which spread and lead to breakage. of bending resistance can be imparted. In general, hardness and repeated bending resistance are incompatible, but the present inventors focused on the difference in the amount of deformation in these tests, and set E ₁₀ and E ₂ in a range that satisfies formulas (1) to (3). I found out that it is compatible by doing.

(Indentation modulus)
The hard coat film of the present invention has the following indentation elastic modulus in an indentation test in which a load is vertically applied from the surface of the hard coat layer opposite to the support using a diamond knoop indenter. A detailed method for measuring the indentation modulus will be described later.
The indentation elastic modulus E2 when indented by ₂ % with respect to the thickness of the hard coat layer is 8 GPa or less, preferably 7.5 GPa or less, and more preferably 7 GPa or less. By setting _E2 within this range, a hard coat film having excellent resistance to repeated bending can be obtained.
The _lower limit of E2 is not particularly limited, but may be, for example, 1 MPa (0.001 GPa) or more.
In addition, the indentation elastic modulus E10 when the hard coat layer is indented ₁₀ % with respect to the thickness is 8 GPa or more, preferably 9 GPa or more. By setting _E10 within this range, a hard coat film with high hardness can be obtained.
Although the upper limit of E10 is not particularly limited, it may be, for example, 80 _Gpa or less.
Also, E ₁₀ −E ₂ is 2 GPa or more, preferably 2.5 GPa or more.

(Repeated bending resistance)
The repeated bending resistance of the hard coat film is preferably 500,000 times or more until the hard coat film cracks or breaks when the hard coat layer is on the inside and the bending curvature radius is 1.0 mm. , more preferably 800,000 times or more, more preferably 1,000,000 times or more. A detailed measurement method of the bending test will be described later.

(Pencil hardness)
The hardness of the hard coat film is preferably 5H or higher, more preferably 6H or higher, and 8H or higher in pencil hardness measured according to Japanese Industrial Standards (JIS) K5600-5-4 (1999). is more preferred.

<Support>
The support of the hard coat film of the invention will be described.

The support preferably has a transmittance in the visible light region of 70% or more, more preferably 80% or more, even more preferably 90% or more. Preferably, the support comprises a polymeric resin.

(polymer resin)
As the polymer resin, a polymer excellent in optical transparency, mechanical strength, thermal stability and the like is preferable.

Examples thereof include polycarbonate-based polymers, polyester-based polymers such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), and styrene-based polymers such as polystyrene and acrylonitrile-styrene copolymers (AS resins). Polyolefins such as polyethylene and polypropylene, norbornene resins, polyolefin polymers such as ethylene/propylene copolymers, (meth)acrylic polymers such as polymethyl methacrylate, vinyl chloride polymers, nylon, and amides such as aromatic polyamides. -based polymer, imide-based polymer, sulfone-based polymer, polyethersulfone-based polymer, polyetherketone-based polymer, polyphenylene sulfide-based polymer, vinylidene chloride-based polymer, vinyl alcohol-based polymer, vinyl butyral-based polymer, arylate-based polymer, polyoxymethylene Examples thereof include a polymer based on a polymer, an epoxy-based polymer, a cellulose-based polymer represented by triacetyl cellulose, a copolymer of the above-mentioned polymers, and a polymer obtained by mixing the above-mentioned polymers.

The support may be any one selected from triacetyl cellulose film, polymethyl methacrylate film, polyamide film, aramid film, polyimide film, polyamideimide film, polyetherimide film, polyesterimide film, and polyethylene terephthalate film. preferable.

In particular, amide-based polymers such as aromatic polyamides and imide-based polymers can be preferably used as a support because they have a large number of times of breaking and bending as measured by an MIT tester according to JIS P8115 (2001) and have a relatively high hardness. . For example, aromatic polyamides as described in Example 1 of Japanese Patent No. 5699454 and polyimides described in Japanese Patent Application Publication No. 2015-508345 and Japanese Patent Application Publication No. 2016-521216 can be preferably used as the support.

The support can also be formed as a cured layer of an ultraviolet curable or heat curable resin such as acrylic, urethane, acrylic urethane, epoxy or silicone.

(softening material)
The support may contain materials that further soften the polymer resin. The softening material refers to a compound that increases the number of times of breaking and bending. As the softening material, a rubbery elastic body, a brittleness improver, a plasticizer, a slide ring polymer and the like can be used.
Specifically, the softening materials described in paragraph numbers [0051] to [0114] of JP-A-2016-167043 can be preferably used as the softening material.

The softening material may be mixed with the polymer resin alone, or may be mixed with a plurality of them as appropriate. Alternatively, the softening material may be used alone or in combination without being mixed with the resin. can also be used as a support.

The amount of these softening materials to be mixed is not particularly limited, and a polymer resin having a sufficient number of times of bending and breaking may be used alone as a support for the film, or the softening materials may be mixed. A sufficient number of times of breaking and folding may be given by using all as a softening material (100%).

(Other additives)
Various additives (eg, ultraviolet absorbers, matting agents, antioxidants, release accelerators, retardation (optical anisotropy) modifiers, etc.) can be added to the support depending on the application. They may be solids or oils. That is, the melting point or boiling point is not particularly limited. In addition, the additive may be added at any point in the process of producing the support, or the process of adding and preparing the additive may be added to the process of preparing the material. Furthermore, the addition amount of each material is not particularly limited as long as the function is exhibited.
As other additives, additives described in paragraph numbers [0117] to [0122] in JP-A-2016-167043 can be preferably used.

One type of the above additives may be used alone, or two or more types may be used in combination.

(Ultraviolet absorber)
Examples of ultraviolet absorbers include benzotriazole compounds, triazine compounds, and benzoxazine compounds. Here, the benzotriazole compound is a compound having a benzotriazole ring, and specific examples thereof include various benzotriazole-based ultraviolet absorbers described in paragraph 0033 of JP-A-2013-111835. A triazine compound is a compound having a triazine ring, and specific examples thereof include various triazine-based ultraviolet absorbers described in paragraph 0033 of JP-A-2013-111835. As the benzoxazine compound, for example, those described in JP-A-2014-209162, paragraph 0031 can be used. The content of the ultraviolet absorber in the support is, for example, about 0.1 to 10 parts by mass with respect to 100 parts by mass of the resin contained in the support, but is not particularly limited. Further, regarding the ultraviolet absorber, JP-A-2013-111835, paragraph 0032, can also be referred to. In addition, in the present invention, an ultraviolet absorber having high heat resistance and low volatility is preferable. Examples of such ultraviolet absorbers include UVSORB 101 (manufactured by Fuji Film Fine Chemicals Co., Ltd.), TINUVIN 360, TINUVIN 460, TINUVIN 1577 (manufactured by BASF), LA-F70, LA-31, LA-46 (manufactured by ADEKA). etc.

From the viewpoint of transparency, the support preferably has a small difference in refractive index between the flexible material and various additives used in the support and the polymer resin.

(Thickness of support)
The thickness of the support is more preferably 100 μm or less, still more preferably 80 μm or less, and most preferably 50 μm or less. If the thickness of the support is reduced, the difference in curvature between the front surface and the back surface when the support is bent becomes smaller, cracks and the like are less likely to occur, and the support does not break even when the support is bent multiple times. On the other hand, the thickness of the support is preferably 3 μm or more, more preferably 5 μm or more, and most preferably 15 μm or more, from the viewpoint of ease of handling of the support.

(Method for preparing support)
The support may be formed by heat-melting a thermoplastic polymer resin, or by solution film forming (solvent casting method) from a solution in which the polymer is uniformly dissolved. In the case of hot-melt film formation, the softening material and various additives described above can be added during hot-melting. On the other hand, when the support is produced by a solution casting method, the above-described softening material and various additives can be added to the polymer solution (hereinafter also referred to as dope) in each preparation step. As for the time of addition, the additive may be added at any time during the dope preparation process, or the process of adding and preparing the additive may be added to the final preparation process of the dope preparation process.

<Hard coat layer>
The hard coat layer of the hard coat film of the present invention will be described. The hard coat layer contains a matrix component and inorganic fine particles.

(matrix component)
From the viewpoint of resistance to repeated bending, the matrix component preferably has an indentation modulus _EM of 0.001 GPa or more and 1.5 GPa or less, more preferably 0.01 GPa or more and 1.0 GPa or less, and 0.1 GPa. It is more preferable to be 0.5 GPa or less. Here, the indentation elastic modulus EM of the matrix component is defined as an indentation test in which a load is applied perpendicularly to a layer composed of the matrix component (matrix layer) using a diamond _knoop indenter. % is the indentation elastic modulus when indented. As will be described later, when the matrix component is a cured product of the matrix-forming composition, the layer formed by curing the matrix-forming composition is subjected to an indentation test in which a vertical load is applied using a diamond knoop indenter. , is the indentation elastic modulus when indented by 2% with respect to the thickness of the matrix layer.

The matrix component is preferably a polymer (cured product) obtained by polymerizing a matrix-forming composition containing a compound having a polymerizable functional group by irradiation with ionizing radiation or heating. Furthermore, in order to keep the indentation modulus _EM within the above range, the polymerizable functional group equivalent in the matrix-forming composition is preferably 250 or more, more preferably 250 or more and 1,000 or less. If the equivalent weight of the polymerizable functional group in the matrix-forming composition is too large, chemical bonds with the functional groups modified on the surface of the inorganic fine particles, which will be described later, are reduced, and the hardness and resistance to repeated bending deteriorate. However, the bonding can be compensated for by adjusting the average primary particle size of the inorganic fine particles and the surface modifier.

The polymerizable functional group equivalent e in the matrix-forming composition is obtained from the following formula (4).
In the formula, the mass _ratio of each component is represented by R ₁ , R ₂ , . _In the case of compounds, the _{molecular weights} ) _are represented by M ₁ , M ₂ , .
In this specification, the weight average molecular weight (Mw) can be measured as a polystyrene-equivalent molecular weight by gel permeation chromatography (GPC) unless otherwise specified. At this time, HLC-8220 (manufactured by Tosoh Corporation) is used as the GPC apparatus, G3000HXL+G2000HXL is used as the column, the flow rate is 1 mL/min at 23° C., and the refractive index (RI) is used for detection. The eluent can be selected from THF (tetrahydrofuran), chloroform, NMP (N-methyl-2-pyrrolidone), m-cresol/chloroform (manufactured by Shonan Wako Pure Chemical Industries, Ltd.). For example, THF is used.

(Compound having a polymerizable functional group)
The matrix-forming composition contains at least a compound having a polymerizable functional group. As the compound having a polymerizable functional group, various monomers, oligomers, and polymers can be used. As the polymerizable functional group (polymerizable group), those polymerizable with light, electron beams, and radiation are preferable, and among these, photopolymerization is possible. functional groups are preferred.

Photopolymerizable functional groups include polymerizable unsaturated groups (carbon-carbon unsaturated double bond groups) such as (meth)acryloyl groups, vinyl groups, styryl groups and allyl groups, epoxy groups and oxetanyl groups. A ring-polymerizable group and the like can be mentioned, and among them, a (meth)acryloyl group is preferable.

Specific examples of compounds having a (meth)acryloyl group include alkylene glycol (meth)acrylate diesters such as neopentyl glycol acrylate, 1,6-hexanediol (meth)acrylate, and propylene glycol di(meth)acrylate;
Polyoxyalkylene glycol (meth)acrylic acid diesters such as triethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and polypropylene glycol di(meth)acrylate;
(meth)acrylic acid diesters of polyhydric alcohols such as pentaerythritol di(meth)acrylate;
(Meth)acrylic diesters of ethylene oxide or propylene oxide adducts such as 2,2-bis{4-(acryloxy-diethoxy)phenyl}propane and 2-2-bis{4-(acryloxy-polypropoxy)phenyl}propane ; etc. can be mentioned.
Furthermore, epoxy (meth)acrylates, urethane (meth)acrylates, and polyester (meth)acrylates are also preferably used as photopolymerizable monomers.

In order to make the polymerizable functional group equivalent in the matrix-forming composition 250 or more and 1000 or less, the compound having a polymerizable functional group preferably has a polymerizable functional group equivalent of 250 or more and 1000 or less. In addition, two or more compounds having a polymerizable functional group may be used in combination. At this time, a compound having a polymerizable functional group equivalent weight of 250 or more and a compound having a polymerizable functional group equivalent weight of 250 or less may be used in combination to form the matrix-forming composition. may be adjusted so that the polymerizable functional group equivalent of is 250 or more and 1000 or less.
The polymerizable functional group equivalent for a compound having a polymerizable functional group is the molecular weight or weight average molecular weight M of the compound having a polymerizable functional group, the number of polymerizable functional groups in one molecule of the compound having a polymerizable functional group C is a value (M/C) divided by

When the compound having a polymerizable functional group is a monomer, a compound having 1 or more and 6 or less polymerizable functional groups in one molecule is preferable, and a compound having 1 or more and 3 or less is more preferable. Certain compounds are particularly preferred. When the compound having a polymerizable functional group is an oligomer or polymer, the polymerizable functional group may be present at the terminal of the main chain or may be present in the side chain.

Specific examples of compounds having a polymerizable functional group equivalent of 250 or more include Nippon Kayaku Co., Ltd. DPCA-120 (molecular weight 1947, number of polymerizable functional groups 6, polymerizable functional group equivalent 325), Nippon Synthetic Chemical Co., Ltd. Shiko UV-3000B (molecular weight 18000, number of functional groups 2, functional group equivalent 9000), UV-3200B (molecular weight 10000, number of functional groups 2, functional group equivalent 5000), UV-3210EA (molecular weight 9000, number of functional groups 2, functional group equivalent 5000) Group equivalent weight 4500), UV-3310B (molecular weight 5000, functional group number 2, functional group equivalent weight 2500), UV-3700B (molecular weight 38000, functional group number 2, functional group equivalent weight 19000), UV-6640B (molecular weight 5000, functional Group number 2, functional group equivalent weight 2500), UV-2000B (molecular weight 13000, functional group number 2, functional group equivalent weight 6500), UV-2750B (molecular weight 3000, functional group number 2, functional group equivalent weight 1500), Shin Nakamura Chemical Industry ( Ltd. ATM-35E (molecular weight 1892, functional group number 4, functional group equivalent weight 473) A-GLY-9E (molecular weight 811, functional group number 3, functional group equivalent weight 270), same A-GLY-20E (molecular weight 1295, functional group number 3, functional group equivalent 432), same A-400 (molecular weight 508, number of functional groups 2, functional group equivalent 254), same A-600 (molecular weight 708, number of functional groups 2, functional group equivalent 354), same A-1000 (molecular weight 1108, functional group number 2, functional group equivalent weight 554), UA-160TM (molecular weight 2700, functional group number 2, functional group equivalent weight 1350), UA-290TM (molecular weight 2900, functional group number 2, functional group equivalent weight 1450), UA -4200 (molecular weight: 1000, number of functional groups: 2, functional group equivalent: 500), UA-4400 (molecular weight: 1400, number of functional groups: 2, functional group equivalent: 700).

The content of the matrix component in the hard coat layer is preferably 10 to 50% by volume, more preferably 25 to 45% by volume.

(Polymerization initiator)
The matrix-forming composition may contain a polymerization initiator.

When the compound having a polymerizable functional group is a photopolymerizable compound, it preferably contains a photopolymerization initiator.
Photopolymerization initiators include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds, fluoroamine compounds, aromatic sulfoniums, lophine dimers, onium salts, borate salts, active esters, active halogens, inorganic complexes, coumarins and the like. Specific examples of the photopolymerization initiator, preferred embodiments, commercial products, etc. are described in paragraphs [0133] to [0151] of JP-A-2009-098658, and can be suitably used in the present invention as well. can.
"Latest UV Curing Technology" {Technical Information Association Co., Ltd.} (1991), p. 159, and "Ultraviolet Curing System" by Kiyomi Kato (published by Sogo Gijutsu Center in 1989), p. 65 to 148 also describe various examples and are useful for the present invention.
The content of the polymerization initiator in the matrix-forming composition is preferably 0.5 to 8% by mass, more preferably 1 to 5% by mass, based on the total solid content in the matrix-forming composition.

(Other additives)
The matrix-forming composition may contain components other than those mentioned above, and may contain, for example, a dispersant, a leveling agent, an antifouling agent, an antistatic agent, an ultraviolet absorber, and the like.

(Inorganic fine particles)
The hard coat layer of the hard coat film of the present invention contains inorganic fine particles.
The hardness can be increased by adding inorganic fine particles to the hard coat layer. Examples of inorganic fine particles include silica particles, titanium dioxide particles, zirconia particles, aluminum oxide particles, diamond powder, sapphire particles, boron carbide particles, silicon carbide particles, and antimony pentoxide particles. Among them, silica particles and zirconia particles are preferable from the viewpoint of ease of modification.

The surfaces of the inorganic fine particles are preferably treated with a surface modifier containing organic segments. The surface modifier preferably has, in the same molecule, a functional group capable of forming a bond with the inorganic fine particles or adsorbing to the inorganic particles and a functional group having a high affinity with the organic component. Examples of surface modifiers having functional groups that can bind to or adsorb to inorganic fine particles include metal alkoxide surface modifiers such as silane, aluminum, titanium, and zirconium; A surface modifier having an anionic group is preferable, and among them, a silane alkoxide surface modifier (silane coupling agent) is preferable from the viewpoint of ease of modification. Further, the functional group having a high affinity with the organic component may simply be a combination of hydrophilicity and hydrophobicity with the matrix component, but is preferably a functional group that can chemically bond with the matrix component, A linking group or a ring-opening polymerizable group is preferred. A preferable inorganic fine particle surface modifier in the present invention is a curable resin having a metal alkoxide or an anionic group and an ethylenically unsaturated double bond group or a ring-opening polymerizable group in the same molecule. The number of ethylenically unsaturated double bond groups or ring-opening polymerizable groups in the same molecule is preferably 1.0 or more and 5.0 or less, more preferably 1.1 or more and 3.0 or less. By setting the number of ethylenically unsaturated double bond groups or ring-opening polymerizable groups in the same molecule within the above range, the bond between the matrix component and the inorganic fine particles can be strengthened.

Specific examples of silane coupling agents include, for example, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropyldimethylmethoxysilane, 3- (Meth) acryloxypropylmethyldiethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 2-(meth)acryloxyethyltrimethoxysilane, 2-(meth)acryloxyethyltriethoxysilane, 4-( Silane coupling agents having an ethylenically unsaturated double bond group such as meth)acryloxybutyltrimethoxysilane, 4-(meth)acryloxybutyltriethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltri Examples include silane coupling agents having a ring-opening polymerizable group such as methoxysilane and 3-glycidoxypropyltrimethoxysilane. More specifically, KBM-303, KBM-403, KBM-503, KBM-5103 (all manufactured by Shin-Etsu Chemical Co., Ltd.) and silane coupling agents C-1 and C represented by the following structural formulas -2 and the like.

The inorganic fine particles are more preferably particles modified with a silane coupling agent having two or more polymerizable functional groups in one molecule.

The inorganic fine particles preferably have 0.2 to 4.0 surface modifiers bound or adsorbed per 1 nm ² surface area of the inorganic fine particles, more preferably 0.5 to 3.0 per 1 nm ² , and 1 nm. More preferably 0.8 to 2.0 per ² . If the number is less than 0.2 per 1 nm ² , a sufficient surface modification effect may not be obtained. On the other hand, if the number is more than 4.0 per 1 nm ² , the modifier tends to be liberated from the surface of the inorganic fine particles.

Surface modification of these inorganic fine particles is preferably carried out in a solution. After the inorganic fine particles are synthesized in a solution, the surface modifier is added and stirred, or the surface modifier is present together when the inorganic fine particles are finely dispersed mechanically, or after the inorganic fine particles are finely dispersed. Either a surface modifier is added to and stirred, or the surface is modified before finely dispersing the inorganic fine particles (if necessary, heated, dried and then heated, or the pH is changed), and then finely A method of dispersion may also be used. As a solution for dissolving the surface modifier, a highly polar organic solvent is preferable. Specific examples include known solvents such as alcohols, ketones, and esters.

The average primary particle size of the inorganic fine particles is 3 to 100 nm, preferably 4 to 50 nm, more preferably 5 to 20 nm. By setting the average primary particle size within the above range, the bond between the matrix component and the inorganic fine particles can be strengthened.
The average primary particle size of the inorganic fine particles in the hard coat film is obtained by slicing the hard coat film into thin slices. Observation is performed, the diameter of each of 100 primary particles is measured, the volume is calculated, and the cumulative 50% particle size is determined as the average primary particle size. If the particles are not spherical, the average of the major and minor diameters is taken as the primary particle diameter. A thin piece sample can be prepared by a microtome method using a cross-section cutting device ultramicrotome, a thin piece processing method using a focused ion beam (FIB) device, or the like. When powder particles or particles in a particle dispersion are measured, the powder particles or particle dispersion are observed with a TEM in the same manner as described above, and the average primary particle diameter is calculated.

The inorganic fine particles may be used alone or in combination of two or more. When two or more kinds are used in combination, it is preferable to use those having different particle diameters from the viewpoint of increasing the volume filling rate of the particles in the hard coat layer.

The volume ratio of the inorganic fine particles in the hard coat layer is 50% by volume or more and 90% by volume or less. The E ₁₀ −E ₂ of the hard coat film can be 2 GPa or more by making it 50 volume % or more. In addition, by making it 90% by volume or less, it becomes easier to form a film.

The inorganic fine particles are preferably solid particles from the viewpoint of particle strength. The shape of the inorganic fine particles is most preferably spherical, but may be non-spherical such as amorphous.

(film thickness)
Although the thickness of the hard coat layer is not particularly limited, it is preferably 1 to 50 μm, more preferably 5 to 30 μm, even more preferably 10 to 20 μm.
The thickness of the hard coat layer is calculated by observing the cross section of the hard coat film with an optical microscope. A cross-section sample can be prepared by a microtome method using a cross-section cutting device ultramicrotome, a cross-section processing method using a focused ion beam (FIB) device, or the like.

<Other layers>
The hard coat film of the present invention may have layers other than the hard coat layer. For example, an embodiment having an easy adhesion layer for improving adhesion between the substrate and the hard coat layer, an embodiment having an antistatic layer for imparting antistatic properties, and an antistatic layer on the hard coat layer. An embodiment having an antifouling layer for imparting stain resistance and a scratch resistant layer for imparting scratch resistance is preferred, and a plurality of these layers may be provided.
For example, it is preferable to further provide a scratch-resistant layer on the outermost surface of the hard coat layer of the hard coat film on the side opposite to the support, whereby the scratch resistance can be improved.
A hard coat film having a hard coat layer that satisfies the formulas (1) to (3) of the present invention is prepared by preparing a hard coat layer-forming composition (coating liquid) containing the above matrix-forming composition and inorganic fine particles. Preferably, the hard coat layer is formed by coating the hard coat layer-forming composition on a support and curing it with light or heat to form a hard coat layer. Further, the hard coat film with a scratch resistant layer of the present invention has a scratch resistant layer formed on the hard coat layer of the hard coat film of the present invention, which contains a compound having 3 or more polymerizable functional groups in one molecule described below. It is preferable that the coating composition (coating liquid) is applied and cured by light or heat to form a scratch-resistant layer.

The composition for forming a hard coat layer preferably contains an organic solvent. As the organic solvent, it is preferable to select an organic solvent having a polarity close to that of the inorganic fine particles from the viewpoint of improving the dispersibility. Examples of the organic solvent include, but are not particularly limited to, organic solvents such as alcohol solvents, ketone solvents, ester solvents, carbonate solvents, and aromatic solvents. A plurality of these organic solvents may be mixed and used as long as the dispersibility is not remarkably deteriorated.

(Scratch resistant layer)
The scratch-resistant layer is preferably a layer containing 80 mass % or more of a cured product of a compound having 3 or more polymerizable functional groups in one molecule, based on the total mass of the scratch-resistant layer.

A compound having three or more polymerizable functional groups in one molecule may be a monomer, an oligomer, or a polymer. When the number of polymerizable functional groups in one molecule of the compound is 3 or more, it is easy to form a dense three-dimensional crosslinked structure, and the polymerizable functional group equivalent (generally when having a (meth)acryloyl group as a polymerizable functional group The indentation hardness of the scratch-resistant layer can be increased even by using a compound having a small acrylic equivalent. The indentation hardness of the scratch resistant layer is preferably 300 MPa or more.
The content of the cured product of the compound having 3 or more polymerizable functional groups per molecule is more preferably 85% by mass or more, still more preferably 90% by mass or more, relative to the total mass of the scratch resistant layer.

The polymerizable functional group is preferably a (meth)acryloyl group, an epoxy group, or an oxetanyl group, more preferably a (meth)acryloyl group or an epoxy group, and most preferably a (meth)acryloyl group.

Monomers having three or more polymerizable functional groups in one molecule include esters of polyhydric alcohols and (meth)acrylic acid. Specifically, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipenta Examples include erythritol tetra(meth)acrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, pentaerythritol hexa(meth)acrylate, etc. In terms of high cross-linking, pentaerythritol triacrylate, pentaerythritol tetraacrylate, or dipentaerythritol Pentaacrylate, dipentaerythritol hexaacrylate, or mixtures thereof are preferred.

The film thickness of the scratch resistant layer is preferably 0.1 μm or more and 1.5 μm or less.

(Other additives)
The scratch-resistant layer may contain components other than those described above, such as inorganic particles, leveling agents, antifouling agents, antistatic agents, surface modifiers, and polymerization initiators.

(Scratch resistance)
In a scratch resistance test in which the surface of the scratch resistant layer is rubbed with steel wool under a load of 1000 g/cm ² , the number of times of rubbing until a scratch that can be visually observed is preferably 100 reciprocations or more, and 1000 reciprocations or more. 10,000 reciprocations or more is more preferable.

EXAMPLES The present invention will be described in more detail with reference to examples below, but the scope of the present invention should not be construed as being limited by these examples.

[Preparation of base material]
(Manufacturing of polyimide powder)
832 g of N,N-dimethylacetamide (DMAc) was added to a 1 L reactor equipped with a stirrer, a nitrogen injector, a dropping funnel, a temperature controller and a condenser under a nitrogen stream, and then the temperature of the reactor was reduced to 25. °C. 64.046 g (0.2 mol) of bistrifluoromethylbenzidine (TFDB) was added thereto and dissolved. While maintaining the resulting solution at 25° C., 31.09 g (0.07 mol) of 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and biphenyltetracarboxylic dianhydride were added. 8.83 g (0.03 mol) of product (BPDA) was added and stirred for a certain period of time to react. After that, 20.302 g (0.1 mol) of terephthaloyl chloride (TPC) was added to obtain a polyamic acid solution with a solid concentration of 13% by mass. Next, 25.6 g of pyridine and 33.1 g of acetic anhydride were added to the polyamic acid solution, stirred for 30 minutes, further stirred at 70° C. for 1 hour, and then cooled to room temperature. 20 L of methanol was added thereto, and the precipitated solid matter was filtered and pulverized. Then, it was dried in vacuum at 100° C. for 6 hours to obtain 111 g of polyimide powder.

[Preparation of base material S-1]
100 g of polyimide powder was dissolved in 670 g of N,N-dimethylacetamide (DMAc) to obtain a 13 wt% solution. The resulting solution was cast on a stainless plate and dried with hot air at 130° C. for 30 minutes. After that, the film was peeled off from the stainless steel plate and fixed to the frame with pins. The frame with the film fixed was placed in a vacuum oven and heated for 2 hours while gradually increasing the heating temperature from 100°C to 300°C, and then gradually. cooled to After the cooled film was separated from the frame, it was further heat treated at 300° C. for 30 minutes as a final heat treatment step to obtain a base material S-1 made of a polyimide film and having a thickness of 30 μm.

[Synthesis of silane coupling agent]
(Synthesis of silane coupling agent C-1)
13.6 g of KBE-9007 manufactured by Shin-Etsu Chemical Co., Ltd., 16.4 g of pentaerythritol triacrylate, 0.1 g of dibutyl tin dilaurate, and 70.0 g of toluene were added to a flask equipped with a reflux condenser and a thermometer, and the mixture was stirred at room temperature for 12 hours. Stirred. After stirring, 500 ppm (parts per million) of methylhydroquinone was added and distilled off under reduced pressure to obtain a silane coupling agent C-1 represented by structural formula (1).

[Synthesis of silane coupling agent C-2]
9.1 g of KBE-9007 manufactured by Shin-Etsu Chemical Co., Ltd., 20.9 g of dipentaerythritol pentaacrylate, 0.1 g of dibutyltin dilaurate, and 70.0 g of toluene were added to a flask equipped with a reflux condenser and a thermometer, and the mixture was kept at room temperature for 12 hours. Stirred. After stirring, the mixture was distilled off under reduced pressure to obtain a silane coupling agent C-2 represented by the structural formula (2).

[Preparation of silica particles]
(Preparation of silica particles P-1)
89.46 kg of pure water and 0.10 kg of 28% by mass ammonia water were charged into a 200 L reactor equipped with a stirrer, a dropping device and a thermometer, and the liquid temperature was adjusted to 90° C. while stirring. While maintaining the liquid temperature in the reactor at 90° C., 10.44 kg of tetramethoxysilane is added dropwise from the dropping device over 102 minutes. Thus, hydrolysis and condensation of tetramethoxysilane were carried out. The resulting colloidal solution was concentrated to 38.8 kg under a reduced pressure of 13.3 kPa using a rotary evaporator to obtain silica particles P-1 having an SiO ₂ concentration of 10.0% by mass. The silica particles P-1 had an average primary particle size of 5 nm.

(Preparation of silica particles P-2)
Silica particles P-2 were obtained in the same manner as silica particles P-1, except that tetramethoxysilane was added dropwise over 114 minutes. The silica particles P-2 had an average primary particle size of 15 nm.

(Preparation of silica particles P-3)
Silica particles P-3 were obtained in the same manner as silica particles P-1, except that tetramethoxysilane was added dropwise over 156 minutes. The silica particles P-3 had an average primary particle size of 50 nm.

(Preparation of silica particles P-4)
Silica particles P-4 were obtained in the same manner as silica particles P-1, except that tetramethoxysilane was added dropwise over 240 minutes. The silica particles P-4 had an average primary particle size of 120 nm.

(Preparation of silica particles P-13)
Silica particles P-13 were obtained in the same manner as silica particles P-1, except that tetramethoxysilane was added dropwise over 216 minutes. The silica particles P-13 had an average primary particle size of 100 nm.

(Preparation of silica particles P-5)
300 g of silica particles P-1 were placed in a 1 L glass reactor equipped with a stirrer. To this, a solution of 6.75 g of 3-methacryloxypropyltrimethoxysilane (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.) dissolved in 20 g of methyl alcohol was dropped and mixed. After that, heat treatment was performed at 95° C. for about 2 hours while mixing and stirring. After cooling, 100 g of 1-methoxy-2-propanol was added, and the by-product methanol was distilled off under reduced pressure. Further, 300 g of 1-methoxy-2-propanol was added in several portions, and water was azeotropically distilled off under reduced pressure so that the solid content became 60% by mass to obtain silica particles P-5. The solid content was calculated from the weight change before and after heating at 150° C. for 30 minutes.

(Preparation of silica particles P-6)
Silica particles P-6 were obtained in the same manner as silica particles P-5 except that silica particles P-1 were replaced with silica particles P-2 and 3-methacryloxypropyltrimethoxysilane was changed to 2.25 g.

(Preparation of silica particles P-7)
Silica particles P-7 were obtained in the same manner as silica particles P-5, except that silica particles P-1 were replaced with silica particles P-3 and 0.68 g of 3-methacryloxypropyltrimethoxysilane was used.

(Preparation of silica particles P-8)
Silica particles P-8 were obtained in the same manner as silica particles P-5 except that silica particles P-1 were replaced with silica particles P-4 and 0.28 g of 3-methacryloxypropyltrimethoxysilane was used.

(Preparation of silica particles P-14)
Silica particles P-14 were obtained in the same manner as silica particles P-5 except that silica particles P-1 were replaced with silica particles P-13 and 0.34 g of 3-methacryloxypropyltrimethoxysilane was used.

(Preparation of silica particles P-9)
Silica particles P-9 were obtained in the same manner as silica particles P-5, except that 3-methacryloxypropyltrimethoxysilane (6.75 g) was changed to silane coupling agent C-1 (13.7 g). .

(Preparation of silica particles P-10)
Silica particles P-5 except that silica particles P-1 were changed to silica particles P-2 and 3-methacryloxypropyltrimethoxysilane (6.75 g) was changed to silane coupling agent C-1 (4.6 g). Silica particles P-10 were obtained in a similar manner.

(Preparation of silica particles P-11)
Silica particles P-5 except that silica particles P-1 were changed to silica particles P-2 and 3-methacryloxypropyltrimethoxysilane (6.75 g) was changed to silane coupling agent C-2 (6.6 g). Silica particles P-11 were obtained in a similar manner.

(Preparation of silica particles P-12)
1-Methoxy-2-propanol (100 g) was added to silica particles P-2 (300 g), and by-product methanol was distilled off under reduced pressure. Further, 1-methoxy-2-propanol (300 g) was added in several portions, and water was azeotropically distilled off under reduced pressure so that the solid content became 60% by mass, to obtain silica particles P-12.

[Preparation of hard coat film]
(Preparation of coating solution for forming hard coat layer)
Coating solutions HC-1 to HC-20 for forming a hard coat layer were prepared by mixing each component with the composition (% by mass) shown in Tables 1 and 2 below. The composition of silica particles is a value as a dispersion with a solid content of 60% by mass.

A-400: Polyethylene glycol #400 diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)
A-200: Polyethylene glycol #200 diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)
A-1000: Polyethylene glycol #1000 diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)
DPCA-120: caprolactone-modified dipentaerythritol hexaacrylate, trade name KAYARAD DPCA-120 (manufactured by Nippon Kayaku Co., Ltd.)
DPCA-60: caprolactone-modified dipentaerythritol hexaacrylate, trade name KAYARAD DPCA-60 (manufactured by Nippon Kayaku Co., Ltd.)
DPCA-20: caprolactone-modified dipentaerythritol hexaacrylate, trade name KAYARAD DPCA-20 (manufactured by Nippon Kayaku Co., Ltd.)
DPHA: a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd.)
DCP-A: Dimethylol-tricyclodecane diacrylate, trade name Light acrylate DCP-A (manufactured by Kyoei Chemical Co., Ltd.)
UA-33H: urethane acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)
A-DPH-6E: Ethylene oxide adduct of dipentaerythritol hexaacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)
Irgacure 184: Photopolymerization initiator (manufactured by BASF)

(Preparation of hard coat film A)
The coating solution HC-1 for forming a hard coat layer was applied onto the substrate S-1 using a gravure coater so that the thickness after curing was 17 μm. After drying at 100° C., an air ^- cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) of 160 W/cm is used while purging nitrogen so that the atmosphere has an oxygen concentration of 100 ppm or less. was irradiated to cure the coating layer to form a hard coat layer, and a hard coat film A was produced.

(Preparation of hard coat films B to T)
Hard coat films B to T were produced in the same manner as for hard coat film A, except that coating solutions HC-2 to HC-20 were used instead of coating solution HC-1.

[Evaluation of hard coat film]
The produced hard coat film was evaluated by the following methods.

(Indentation modulus)
A HM2000 type hardness tester (Knoop indenter made by Diamond, manufactured by Fisher Instruments) was used for the hard coat layer surface of each hard coat film, and the maximum indentation depth was 0.34 μm (2% with respect to the thickness of the hard coat layer). The maximum load was adjusted to 1.7 μm (10% of the same), and an indentation test was performed under the conditions of an indentation speed of 10 seconds and a creep of 5 seconds to determine the indentation elastic modulus at each indentation depth.

(Volume ratio of inorganic fine particles in hard coat layer)
The surface of the hard coat film was scraped off with a scraper, and 10 g or more of the hard coat layer was collected and weighed. The recovered hard coat layer was heated at 600° C. for 3 hours in an air atmosphere to burn the matrix component, recover inorganic fine particles, and measure the mass. Assuming that the specific gravity of the matrix component was 1.2 and the specific gravity of the silica particles was 2.2, the inorganic fine particle volume ratio in the hard coat layer was determined.

(Pencil hardness)
Measured according to JIS K 5600-5-4 (1999).

(Evaluation of bending resistance (repeated bending resistance))
A sample film having a width of 15 mm and a length of 150 mm was cut out from the hard coat film and allowed to stand at a temperature of 25° C. and a relative humidity of 65% for 1 hour or longer. After that, using a folding endurance tester (IMC-0755 manufactured by Imoto Seisakusho Co., Ltd., bending curvature radius 1.0 mm), repeated bending endurance tests were performed with the hard coat layer side facing the inside of the bend. rice field. Evaluation was made according to the following criteria based on the number of times until cracks or breaks occurred in the sample film.
A: 1,000,000 times or more B: 800,000 times or more, less than 1,000,000 times C: 500,000 times or more, less than 800,000 times D: 100,000 times or more, less than 500,000 times E: Less than 100,000 times

(Indentation modulus of matrix component)
A matrix layer-forming composition prepared without adding silica particles was prepared for each of the hard coat layer-forming coating liquids, and a matrix layer was formed on the substrate S-1 by the same method as for the hard coat layer. formed. The coating amount was adjusted so that the thickness of the matrix layer was 17 μm. An indentation test was performed in the same manner as for the hard coat films A to T except that the maximum load was adjusted so that the maximum indentation depth on the surface of the matrix layer was 0.34 μm (2% with respect to the thickness of the matrix layer). The indentation modulus _EM of the matrix component was measured. The evaluation results are shown in Tables 3 and 4 below.

[Preparation of Hard Coat Film with Scratch Resistant Layer]
(Preparation of hard coat film A-2)
The coating liquid HC-1 for forming a hard coat layer was applied onto the substrate S-1 using a gravure coater so that the thickness after curing was 17 μm. After drying at 100° C., an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) of 20 W/cm is used while purging nitrogen so that the atmosphere has an oxygen concentration of 1.5% or less, and the irradiation amount is 20 mJ/cm. The coating layer was cured by irradiating the ultraviolet rays of No. ² to form a hard coat layer, thereby producing a hard coat film A-2.

(Preparation of Coating Liquid for Forming Scratch Resistant Layer)
Coating solutions SC-1 and SC-2 for forming a scratch resistant layer were prepared by mixing each component with the composition (% by mass) shown in Table 5 below.

Irgacure 127: polymerization initiator (manufactured by BASF)
RS-90: surface modifier, trade name Megafac RS-90 (manufactured by DIC Corporation)

(Preparation of Hard Coat Film U with Scratch Resistant Layer)
Coating solution SC-1 for forming a scratch resistant layer was applied onto the hard coat layer of hard coat film A-2 using a gravure coater so that the thickness after curing was 0.1 μm, and dried at 100°C. . After that, on a hot plate at 80 ° C., while purging with nitrogen to create an atmosphere with an oxygen concentration of 100 ppm or less, an air-cooled metal halide lamp of 160 mW / cm ² (manufactured by Eye Graphics Co., Ltd.) was used, and the irradiation amount was 1200 mJ / cm. A hard coat film U with a scratch resistant layer was prepared by irradiating the ultraviolet rays of No. ² from the coating film side to cure the film.

(Preparation of Hard Coat Film V with Scratch Resistant Layer)
A hard coat film V with a scratch resistant layer was prepared in the same manner as the hard coat film U with a scratch resistant layer except that the coating liquid for forming the scratch resistant layer was changed to SC-2 and the thickness after curing was 1.0 μm. did.

[Evaluation of Hard Coat Film with Scratch Resistant Layer]
The produced hard coat film with a scratch resistant layer was evaluated by the following methods.

(Scratch resistance)
Using a rubbing tester, the surface of the scratch-resistant layer of the hard coat film with the scratch-resistant layer was subjected to a rubbing test under the following conditions to obtain an index of scratch resistance.
Evaluation environment conditions: 25°C, relative humidity 60%
Rubbing material: steel wool (manufactured by Japan Steel Wool Co., Ltd., grade No. 0000)
Wrap around the scraping tip (1 cm x 1 cm) of the tester that comes into contact with the sample and fix the band Moving distance (one way): 13 cm,
Rubbing speed: 13 cm/sec,
Load: 1000g/ ^cm2
Tip contact area: 1 cm x 1 cm,
Number of times of rubbing: 100 reciprocations, 10,000 reciprocations Oil-based black ink was applied to the back side of the rubbed sample, and the scratches on the rubbed portions were evaluated by visual observation with reflected light.
A: No flaws are visible even when viewed very carefully.
B: If you look carefully, you can see a weak scratch, but it is not a problem. C: There is a scratch that can be seen at a glance, and it is very conspicuous.

The evaluation results are shown in Table 6 below.

As shown in Tables 3 and 4, the hard coat films of Examples were excellent in both hardness and resistance to repeated bending. On the other hand, the hard coat films of Comparative Examples 1 to 6 and 9 have E ₂ larger than 8 GPa and are inferior in repeated bending resistance, and the hard coat films of Comparative Examples 7, 8 and 11 have E ₁₀ smaller than 8 GPa. Poor pencil hardness. In addition, the hard coat film of Comparative Example 10 had an average primary particle size of more than 100 nm, and was inferior in both pencil hardness and resistance to repeated bending. Moreover, as shown in Table 6, Examples 10 and 11 provided with a scratch-resistant layer were excellent in hardness, repeated bending property, and scratch resistance.

ADVANTAGE OF THE INVENTION According to this invention, the hard coat film which has high hardness and is excellent in resistance to repeated bending, and the hard coat film with an abrasion-resistant layer which is excellent in abrasion resistance can be provided.

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.
This application is based on a Japanese patent application filed on March 9, 2018 (Japanese patent application 2018-43373) and a Japanese patent application filed on September 28, 2018 (Japanese patent application 2018-185805). is incorporated here by reference.

Claims (5)

A hard coat film having a hard coat layer on at least one surface of a support,
In an indentation test in which a load is applied vertically using a diamond knoop indenter from the surface of the hard coat layer opposite to the support side, the indentation when indented by 10% with respect to the thickness of the hard coat layer When the elastic modulus is E ₁₀ and the indentation elastic modulus when pushed 2% with respect to the thickness of the hard coat layer is E ₂ , the following formulas (1), (2) and (3) are satisfied,
the support is selected from triacetylcellulose film, polymethyl methacrylate film, polyamide film, aramid film, polyimide film, polyamideimide film, polyetherimide film, polyesterimide film, and polyethylene terephthalate film;
A hard coat film, wherein, in a bending resistance test in which the hard coat layer is placed inside and the bending curvature radius is 1.0 mm, the number of times until the hard coat film cracks or breaks is 500,000 times or more.
E ₁₀ −E ₂ ≧2 GPa (1)
E ₁₀ ≧8 GPa (2)
E ₂ ≤ 8 GPa (3) 2. The hard coat film according to claim 1, which has a pencil hardness of 4H or more measured according to JIS K5600-5-4 (1999). 3. The hard coat film according to claim 1, wherein said hard coat layer does not contain particles, or when it contains particles, said particles have an average primary particle size of 3 to 100 nm. The hard coat film according to any one of claims 1 to 3, wherein the hard coat layer does not contain particles, or when the hard coat layer contains particles, the particles are inorganic fine particles. A hard coat film with a scratch resistant layer, comprising a scratch resistant layer on the surface of the hard coat layer opposite to the support side of the hard coat film according to any one of claims 1 to 4.