JP5088297B2 - Hard coat film - Google Patents

Description

  The present invention relates to a hard coat film provided with a hard coat layer on a transparent substrate film, which is used for the purpose of protecting the surface of a display or the like.

  An image display surface in an image display device such as a liquid crystal display, a CRT display, a projection display, a plasma display, or an electroluminescence display is required to be provided with scratch resistance so as not to be damaged during handling. On the other hand, by using a hard coat film in which a hard coat (HC) layer is provided on a base film, and a hard coat film (optical laminate) having optical functions such as antireflection and antiglare properties. Generally, the scratch resistance of the image display surface of the image display device is improved.

  As a method for improving the hardness of the hard coat layer, there is a method of adding inorganic fine particles, and generally, a hard coat film in which a hard coat layer having inorganic fine particles added is provided on a base film has been produced.

  In Patent Document 1, an intermediate layer obtained by curing a composition containing a photocurable resin and a thermosetting resin is provided on a transparent substrate, and a hard coat layer is further provided on the intermediate layer to improve hardness. ing.

  Since components such as curable resins such as the above-mentioned photocurable resin and thermosetting resin cure and shrink, warpage of the hard coat film including the transparent base film and the entire optical laminate to the hard coat layer side ( There is a problem that the workability is remarkably impaired when the hard coat film or the optical laminate is attached to a polarizer or a display.

JP 2008-107762 A

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a hard coat film that has excellent hardness and can reduce curling.

As a result of intensive studies on the above problems, the present inventors have determined that the film thickness and the Vickers hardness of the two hard coat layers provided on the transparent substrate film are within a certain range, and The inventors have found that the difference in the Vickers hardness of the coat layer is within a certain range, the hardness is excellent and curling can be reduced, and the present invention has been completed.
That is, the features of the present invention that solve the above problems are as follows.

The hard coat film according to the present invention has a second hard coat on one side of the transparent base film adjacent to the first hard coat layer and the first hard coat layer from the side close to the transparent base film. A hard coat film provided with a layer,
The first hard coat layer comprises reactive silica fine particles (A) having an average particle diameter of 10 to 100 nm having a reactive functional group a on the particle surface,
A polyfunctional monomer (B) having 3 or more reactive functional groups b in one molecule and a molecular weight of 1000 or less, and
The reactive silica fine particle comprising a cured product of a first curable resin composition containing a polymer (C) having 30 or more reactive functional groups c in the molecular side chain and a weight average molecular weight of 10,000 to 50,000. (A) is included in an amount of 30 to 65% by weight based on the total solid content of the first curable resin composition,
The second hard coat layer comprises reactive silica fine particles (D) having an average particle diameter of 10 to 100 nm having a reactive functional group d on the particle surface, and
It consists of a cured product of a second curable resin composition containing a polyfunctional monomer (E) having 3 or more reactive functional groups e in one molecule and a molecular weight of 1000 or less, and the reactive silica fine particles ( D) is 0 wt% or more and less than 30 wt% with respect to the total solid content of the second curable resin composition,
The reactive functional groups a, b, c, d and e have cross-linking reactivity between the same and different reactive functional groups, respectively, and
Each of the first hard coat layer and the second hard coat layer has a film thickness of 20 μm or less, a Vickers hardness of 53 to 69 Hv at an indentation load of 100 mN, and the first hard coat layer and the second hard coat layer. The absolute value of the difference in Vickers hardness of the coat layer is 13 or less.

  The reactive silica fine particles (A) and the reactive silica fine particles (D) each have an average particle diameter of 10 to 100 nm, and thus are light transmissive to the first hard coat layer and the second hard coat layer. Hardness is imparted while maintaining

  When the reactive silica fine particles (A) are contained in an amount of 30 to 65% by weight based on the total solid content of the first curable resin composition, sufficient hardness is imparted to the first hard coat layer serving as a base. The Further, the reactive silica fine particles (D) are contained in the second hard coat layer on the surface side appropriately by containing 0 wt% or more and less than 30 wt% with respect to the total solid content of the second curable resin composition. Flexibility. Further, the Vickers hardness of the first hard coat layer and the second hard coat layer is 53 to 69 Hv, respectively, and the absolute value of the difference between the Vickers hardness of the two layers is within 13 so that the hard coat film has Contributes to improved hardness and reduced curl.

  In the present invention, the Vickers hardness is a Vickers hardness defined in JIS Z 2244 (2003). However, with the 10 μm thick first or second hard coat layer formed on the 40 μm thick triacetyl cellulose film as a test sample film, the indentation load is 100 mN, the load time is 8 seconds, The Vickers hardness test specified in JIS Z 2244 (2003) was conducted three times under the conditions of holding time of 5 seconds and weight reduction time of 8 seconds, and the average value of the hardness calculated therefrom was used as the first or second hardness. The Vickers hardness of the coat layer.

  A polyfunctional monomer (B) having 3 or more reactive functional groups b in one molecule and a molecular weight of 1000 or less, and 30 or more reactive functional groups c in the molecular side chain and having a weight average molecular weight By combining the polymer (C) which is 10,000 to 50,000, it contributes to the improvement of the hardness of the first hard coat layer.

  The second curable resin composition includes a polyfunctional monomer (E) having three or more reactive functional groups e in one molecule and a molecular weight of 1000 or less, thereby forming a second hard coat layer. Give moderate flexibility.

  The reactive functional groups a, b, c, d, and e have cross-linking reactivity between the same and different reactive functional groups, respectively. As a result, when the first and second curable resin compositions are cured, the reactive functional groups can be cross-linked to form a network structure, which contributes to improving the hardness of the hard coat film. .

In the present invention, the average particle diameter of the fine particles is a 50% particle diameter (d50 median diameter) when the fine particles in the solution are measured by a dynamic light scattering method and the particle size distribution is represented by a cumulative distribution. means. The said average particle diameter can be measured using the Nikkiso Co., Ltd. Microtrac particle size analyzer or Nanotrac particle size analyzer.
The fine particles may be agglomerated particles, and in the case of agglomerated particles, the secondary particle diameter may be within the above range.

  In a preferred embodiment of the hard coat film according to the present invention, the hardness of the pencil hardness test (4.9 N load) specified in JIS K5600-5-4 (1999) is 4H or more, and the hard coat film is The film cut to a size of 10 × 10 cm is placed on a flat surface with the transparent base film facing down, and the average value of the distance between the end points of the sides constituting the raised curved surface is 1 to 85 mm. It is also possible.

  The hard coat film according to the present invention comprises a two-layer hard coat layer made of a cured product of the first and second curable resin compositions, and a first hard coat layer on one side of the transparent substrate film, A second hard coat layer is provided adjacent to the opposite side of the transparent substrate film of the first hard coat layer, and each of the two hard coat layers has a film thickness of 20 μm or less, a Vickers hardness, When the absolute value of the difference in Vickers hardness between the two layers is within 13 to 53 Hv, curl is reduced while having excellent hardness.

  Hereinafter, first, the hard coat film according to the present invention will be described, and then the transparent base film, the first hard coat layer, the second hard coat layer, and the optional hard coat film as essential components of the hard coat film. The antistatic layer, antiglare layer, antifouling layer, low refractive index layer, and third hard coat layer that is the same as or different from the first and second hard coat layers can be described in order.

  In the present invention, the Vickers hardness is a Vickers hardness defined in JIS Z 2244 (2003). However, with the 10 μm thick first or second hard coat layer formed on the 40 μm thick triacetyl cellulose film as a test sample film, the indentation load is 100 mN, the load time is 8 seconds, The Vickers hardness test specified in JIS Z 2244 (2003) was conducted three times under the conditions of holding time of 5 seconds and weight reduction time of 8 seconds, and the average value of the hardness calculated therefrom was used as the first or second hardness. The Vickers hardness of the coat layer.

In the present invention, the average particle diameter of the fine particles is a 50% particle diameter (d50 median diameter) when the particles in the solution are measured by a dynamic light scattering method and the particle size distribution is expressed as a cumulative distribution. means. The said average particle diameter can be measured using the Nikkiso Co., Ltd. Microtrac particle size analyzer or Nanotrac particle size analyzer.
The fine particles may be agglomerated particles, and in the case of agglomerated particles, the secondary particle diameter may be within the above range.

In the present invention, (meth) acrylate represents acrylate and / or methacrylate.
In the present invention, the “hard coat layer” indicates a hardness of “H” or higher in a pencil hardness test under a 4.9N load generally defined by JISK5600-5-4 (1999).
The light of the present invention includes not only electromagnetic waves having wavelengths in the visible and non-visible regions, but also particle beams such as electron beams, and radiation or ionizing radiation that collectively refers to electromagnetic waves and particle beams.
Moreover, in this invention, a film thickness means the film thickness at the time of drying (dry film thickness).
In the present invention, the molecular weight means a weight average molecular weight which is a polystyrene equivalent value measured by gel permeation chromatography (GPC) when having a molecular weight distribution, and when having no molecular weight distribution, Mean molecular weight.

I. Hard Coat Film The hard coat film according to the present invention has a second surface adjacent to the first hard coat layer and the first hard coat layer from the side close to the transparent base film on one side of the transparent base film. A hard coat film provided with a hard coat layer of
The first hard coat layer comprises reactive silica fine particles (A) having an average particle diameter of 10 to 100 nm having a reactive functional group a on the particle surface,
A polyfunctional monomer (B) having 3 or more reactive functional groups b in one molecule and a molecular weight of 1000 or less, and
The reactive silica fine particle comprising a cured product of a first curable resin composition containing a polymer (C) having 30 or more reactive functional groups c in the molecular side chain and a weight average molecular weight of 10,000 to 50,000. (A) is included in an amount of 30 to 65% by weight based on the total solid content of the first curable resin composition,
The second hard coat layer comprises reactive silica fine particles (D) having an average particle diameter of 10 to 100 nm having a reactive functional group d on the particle surface, and
It consists of a cured product of a second curable resin composition containing a polyfunctional monomer (E) having 3 or more reactive functional groups e in one molecule and a molecular weight of 1000 or less, and the reactive silica fine particles ( D) is 0 wt% or more and less than 30 wt% with respect to the total solid content of the second curable resin composition,
The reactive functional groups a, b, c, d and e have cross-linking reactivity between the same and different reactive functional groups, respectively, and
Each of the first hard coat layer and the second hard coat layer has a film thickness of 20 μm or less, a Vickers hardness of 53 to 69 Hv at an indentation load of 100 mN, and the first hard coat layer and the second hard coat layer. The absolute value of the difference in Vickers hardness of the coat layer is 13 or less.

  The reactive silica fine particles (A) and the reactive silica fine particles (D) each have an average particle diameter of 10 to 100 nm, and thus are light transmissive to the first hard coat layer and the second hard coat layer. Hardness is imparted while maintaining

  When the reactive silica fine particles (A) are contained in an amount of 30 to 65% by weight based on the total solid content of the first curable resin composition, sufficient hardness is imparted to the first hard coat layer serving as a base. The Moreover, since the reactive silica fine particles (D) are contained in an amount of 0% by weight or more and less than 30% by weight with respect to the total solid content of the second curable resin composition, it is appropriate for the second hard coat layer on the surface side. Flexibility is added. Further, the Vickers hardness of the first hard coat layer and the second hard coat layer is 53 to 69 Hv, respectively, and the absolute value of the difference between the Vickers hardness of the two layers is within 13 so that the hard coat film has Contributes to improved hardness and reduced curl.

  The sample film for Vickers hardness test is desirably flat, but depending on the sample film, the curl is large, and therefore it may be difficult to measure the Vickers hardness. In that case, the measurement is performed after the sample film is flattened. As a flattening method, for example, a sample film having a size of 2 cm square is adhered to a glass having a thickness of 1 mm or more with a minimal amount of instantaneous adhesive, and the sample film is lightly bonded to the glass, Place another flat glass on the surface of the second hard coat layer, sandwich the sample film, leave it on the glass on the second hard coat layer with a weight of 500 g for 24 hours, and then put it on the second hard coat layer. The glass placed on the coat layer is removed to obtain a sample film having a flat layer structure of glass / adhesive layer / TAC / hard coat resin layer.

FIG. 1 is a cross-sectional view schematically showing an example of a layer configuration of a hard coat film according to the present invention.
A first hard coat layer 20 is provided on one side of the transparent base film 10, and a second hard coat layer 30 is provided on the opposite side of the first hard coat layer 20 from the transparent base film 10. It has been. Each of the first hard coat layer 20 and the second hard coat layer 30 has a Vickers hardness of 53 to 69 Hv, and the absolute value of the difference between the two layers of Vickers hardness is 13 or less.

FIG. 2a is a schematic view showing an example of a cross section of the hard coat film 1 in a state where it is not curled, and FIG. 3a is a schematic view showing an example of a cross section of the hard coat film 1 in a state of being curled.
2b is a perspective view schematically showing an example of the hard coat film 1 in an uncurled state, and FIG. 3b schematically shows an example of the hard coat film 1 in a curled state. FIG.

  In a preferred embodiment of the hard coat film according to the present invention, the hardness of the pencil hardness test (4.9 N load) specified in JIS K5600-5-4 (1999) is 4H or more, and the hard coat film is The film cut to a size of 10 × 10 cm is placed on a flat surface with the transparent base film facing down, and the average value of the distance between the end points of the sides constituting the raised curved surface is 1 to 85 mm. It is also possible.

In the present invention, the degree of curl (curl width) is measured by placing the hard coat film cut to a size of 10 cm × 10 cm on a flat surface with the transparent base film facing down, and observing the lifted state at both ends. The average value (mm) of the distance between the end points of the sides constituting the raised curved surface is shown.
Specifically, for example, in FIG. 3b, among the four end points (2, 3, 4 and 5) of the hard coat layer, the average value (mm) of the distance 6 between the end points 3-4 and 5-2 is shown. .

  In FIG. 4, when the curled hard coat film is viewed as a disk, the angle formed by the sides 2-3 and 4-5 with respect to the center of the circle is defined as a central angle 40. When the degree of curl (curl width) increases, the central angle 40 may be 360 degrees or more. A state where the central angle is 360 degrees or more is defined as a roll-shaped object. In the case of a roll-shaped object, the curl width is expressed as φx by using the diameter of the circular portion of the roll-shaped object to be formed. For example, when the diameter of the circular part of the roll-shaped object is 15 mm, it is expressed as φ15.

  Hereinafter, the transparent base film, the first hard coat layer, the second hard coat layer, and the antistatic layer that can be appropriately provided as necessary, which are essential constituents of the hard coat film according to the present invention, and the antiglare layer The other layers of the third hard coat layer that are the same as or different from the first hard coat layer and the first hard coat layer will be described in detail.

1. Transparent substrate film The transparent substrate film used in the present invention is a plastic film or sheet having high transparency (light transmittance), and is particularly limited as long as it satisfies physical properties that can be used as a transparent substrate of an optical laminate. It can be selected and used as appropriate.
Usually, the base film used for the optical layered body is transparent, semi-transparent, colorless, or colored, but is required to have light transmittance. In addition, the measurement of light transmittance uses the value measured in room temperature and air | atmosphere using the ultraviolet visible spectrophotometer (For example, Shimadzu Corporation UV-3100PC).

  In the present invention, the thickness of the transparent substrate film can be appropriately selected and used, but a transparent substrate having a thickness of 10 to 200 μm is used from the viewpoint of hardly cracking the surface of the hard coat film and imparting hardness. It is preferable that it is 30-150 micrometers.

  Preferable materials for the transparent substrate film include cellulose acylate, cycloolefin polymer, polycarbonate, acrylate polymer, or polyester. Here, “mainly” means a component having the highest content ratio among the constituent components of the base material.

Specific examples of cellulose acylate include cellulose triacetate, cellulose diacetate, and cellulose acetate butyrate.
Examples of the cycloolefin polymer include a norbornene polymer, a monocyclic olefin polymer, a cyclic conjugated diene polymer, a vinyl alicyclic hydrocarbon polymer resin, and more specifically, ZEONEX and ZEONOR (norbornene resin) manufactured by Nippon Zeon Co., Ltd., Sumilite FS-1700 manufactured by Sumitomo Bakelite Co., Ltd., Arton (modified norbornene resin) manufactured by JSR Corporation, Appel (cyclic olefin) manufactured by Mitsui Chemicals Copolymer), Topas (cyclic olefin copolymer) manufactured by Ticona, Optretz OZ-1000 series (alicyclic acrylic resin) manufactured by Hitachi Chemical Co., Ltd., and the like.
Specific examples of the polycarbonate include aromatic polycarbonates based on bisphenols (such as bisphenol A) and aliphatic polycarbonates such as diethylene glycol bisallyl carbonate.
Specific examples of the acrylate polymer include methyl poly (meth) acrylate, poly (meth) ethyl acrylate, methyl (meth) acrylate-butyl (meth) acrylate, and the like.
Specific examples of the polyester include polyethylene terephthalate and polyethylene naphthalate.

As the transparent substrate film used in the present invention, the material having the highest transparency is cellulose acylate, and among them, triacetyl cellulose is preferably used.
A triacetyl cellulose film (TAC film) is a light-transmitting substrate capable of setting an average light transmittance to 50% or more in a visible light region of 380 to 780 nm. The average light transmittance of the substrate film is preferably 70% or more, and more preferably 85% or more.
Since the TAC film has optical isotropy, it can be preferably used in the case of a liquid crystal display application.

  In addition, as triacetyl cellulose in the present invention, in addition to pure triacetyl cellulose, cellulose acetate propionate, cellulose acetate butyrate, and the like are used in combination with components other than acetic acid as fatty acids forming esters with cellulose. Also good. These triacetyl celluloses may be added with other cellulose lower fatty acid esters such as diacetyl cellulose or various additives such as a plasticizer, an antistatic agent, and an ultraviolet absorber as required.

  In the present invention, the TAC film may be subjected to a surface treatment (eg, saponification treatment, glow discharge treatment, corona discharge treatment, ultraviolet (UV) treatment, flame treatment). The transparent base film in the present invention includes those including these surface treatments.

2. First hard coat layer The first hard coat layer comprises reactive silica fine particles (A) having a reactive functional group a on the particle surface and an average particle diameter of 10 to 100 nm, and 3 reactive functional groups b in one molecule. A polyfunctional monomer (B) having a molecular weight of 1000 or less, and a polymer (C) having 30 or more reactive functional groups c in the molecular side chain and a weight average molecular weight of 10,000 to 50,000. It consists of hardened | cured material of the 1st curable resin composition to contain, and reactive silica microparticles | fine-particles (A) are contained 30 to 65weight% with respect to the total solid of a 1st curable resin composition.
The reactive silica fine particles (A), the polyfunctional monomer (B), and the polymer (C) are contained, and the reactive silica fine particles (A) are contained in an amount of 30 to 65% by weight based on the total solid content of the composition. By curing one curable resin composition, the first hard coat layer functions as a base layer.

  The first hard coat layer has a thickness of 20 μm or less, a Vickers hardness of 53 to 69 Hv, and an absolute value of a difference from the Vickers hardness of the second hard coat layer to be described later is 13 or less.

In addition, in this invention, Vickers hardness is Vickers hardness prescribed | regulated to JISZ2244 (2003), and the specific example of a measuring method is described below.
First, the first curable resin composition was coated on a 40 μm thick triacetyl cellulose film (Konica Minolta Co., Ltd., product name KC4UYW) using a Mayer bar, and the solvent was dried as necessary. And cured by irradiating with 120 mJ / cm ² ultraviolet rays to form a hard coat layer having a thickness of 10 μm, and preparing a sample film for a Vickers hardness test having a two-layer structure of triacetyl cellulose film / first hard coat layer To do.
Next, this sample film was subjected to the Vickers hardness test (indentation load 100 mN, load time 8 seconds, holding time 5 seconds, weight loss time 8 seconds) specified in JIS Z 2244 (2003) three times, and three times. The average value of the calculated hardness is defined as the Vickers hardness of the first hard coat layer.
In addition, when calculating | requiring the Vickers hardness of a 2nd hard-coat layer, in the said specific example, instead of a 1st curable resin composition, a 2nd hard-coat layer is used using a 2nd curable resin composition. In the same manner, the Vickers hardness test is similarly performed three times, and the average value thereof may be obtained.

  The sample film for Vickers hardness test is desirably flat, but depending on the sample film, the curl is large, and therefore it may be difficult to measure the Vickers hardness. In that case, the measurement is performed after the sample film is flattened. As a flattening method, for example, a sample film having a size of 2 cm square is adhered on a glass having a thickness of 1 mm or more with a minimum amount of instantaneous adhesive, and the sample film is lightly bonded to the glass and then hardened. Place another flat glass on the surface of the coat layer, sandwich the sample film, and leave it on the glass on the first or second hard coat layer for 24 hours with a weight of 500 g. There is a method of removing the glass placed on the second hard coat layer and obtaining a sample film having a flat glass / adhesive layer / TAC / first or second hard coat layer structure.

The film thickness of the first hard coat layer is 20 μm or less, preferably 2 to 18 μm, and more preferably 5 to 15 μm. If it is thinner than 2 μm, the hardness may be insufficient. If it exceeds 20 μm, curling and cracking may occur.
Moreover, when exceeding 20 micrometers, when using the triacetyl cellulose (TAC) as a transparent base film especially and making the hard coat film of this invention into a polarizing plate, polyvinyl alcohol (PVA) and TAC used as the base material of a polarizing plate, When the bonding is performed, drying of the solvent or water contained in the adhesive becomes insufficient, and there is a possibility that the solvent or water remains between TAC and PVA.

  Hereinafter, reactive silica fine particles (A), polyfunctional monomer (B), and polymer (C) contained in the first curable resin composition, and other solvents such as a solvent used as necessary and a polymerization initiator The components of will be described.

(Reactive silica fine particles (A))
By containing the reactive silica fine particles (A) having an average particle size of 10 to 100 nm in the first curable resin composition in an amount of 30 to 65% by weight based on the total solid content of the first curable resin composition, Hardness can be imparted to the first hard coat layer made of a cured product of the first curable resin composition.

  The reactive silica fine particles (A) may be agglomerated particles as long as the average particle size is 10 to 100 nm. In the case of agglomerated particles, the secondary particle size is within the above range and reacts with the surface of the agglomerated particles. It only has to have a functional functional group a. When the average particle size of the reactive silica fine particles (A) is less than 10 nm, it is difficult to impart sufficient hardness to the first hard coat layer, and the contact of the particles with the transparent base film or the second hard coat layer is difficult. Since the area increases, the adhesion may decrease, which is not preferable. If the average particle size exceeds 100 nm, the transparency of the first hard coat layer may be lowered.

  In addition, in the 1st hard coat layer which the 1st curable resin composition hardened | cured reactive silica microparticles | fine-particles (A), one part or all part of the reactive functional group a mentions the polyfunctional monomer (B) mentioned later or Since it is used for the crosslinking reaction with the polymer (C), the reactive silica fine particles (A) contained in the first curable resin composition and the silica fine particles contained in the hard coat layer are strictly different.

  In addition, the reactive silica fine particles (A) improve the hardness while maintaining the restoration rate when the polyfunctional monomer (B) and the polymer (C) described later are used in combination without impairing transparency. Therefore, the particle size distribution is preferably narrow and monodispersed.

  The content of the reactive silica fine particles (A) in the first curable resin composition is 30 to 65% by weight with respect to the total solid content of the first curable resin composition, but is 40 to 60% by weight. % Is more preferable. When it is less than 30% by weight, the hardness of the hard coat film surface is insufficient. When the amount exceeds 65% by weight, the adhesion between the reactive silica fine particles (A) and the polyfunctional monomer (B) and polymer (C) described later is deteriorated, and instead the hardness of the first hard coat layer is lowered. .

  The reactive silica fine particles (A) may be used not only having a single average particle diameter but also a combination of two or more kinds having different average particle diameters. When two or more types are used in combination, the average particle diameter of each particle may be within 10 to 100 nm and the total weight percent of each particle may be 30 to 65 weight percent.

In addition to the high hardness of the particles themselves, the silica (SiO ₂ ) fine particles have a refractive index of about 1.46, a polyfunctional monomer (B) (refractive index of about 1.50) described later, and a polymer (C) (refractive). The refractive index of the first hard coat layer is lowered.
The reactive silica fine particles (A) may further impart a function to the hard coat layer, and are appropriately selected and used according to the purpose.

  The silica fine particles (hereinafter simply referred to as “silica fine particles”, meaning the silica fine particles having no reactive functional group) as the core of the reactive silica fine particles (A) of the present invention are like hollow particles. From the viewpoint of improving hardness, it is preferable to use solid particles having no pores or porous structure inside the particles, rather than particles having pores or a porous structure inside such particles.

  The reactive silica fine particles (A) have at least a part of the surface coated with an organic component and have a reactive functional group a introduced by the organic component on the surface. Here, the organic component is a component containing carbon. In addition, as an aspect in which at least a part of the surface is coated with an organic component, for example, a compound containing an organic component such as a silane coupling agent reacts with a hydroxyl group present on the surface of the metal oxide fine particles, A mode in which an organic component is bonded to a part of the surface, or a mode in which a compound containing an organic component having an isocyanate group reacts with a hydroxyl group present on the surface of a metal oxide fine particle, and the organic component is bonded to a part of the surface. In addition, for example, an aspect in which an organic component is attached to a hydroxyl group present on the surface of the metal oxide fine particle by an interaction such as hydrogen bonding, an aspect in which one or more inorganic fine particles are contained in the polymer particle, and the like Is included.

The reactive functional group a includes reactive functional groups a, a reactive functional group b of a polyfunctional monomer (B) described later, a reactive functional group c of a polymer (C), and reactive silica fine particles (D). It also has cross-linking reactivity with the reactive functional group d and the reactive functional group e of the polyfunctional monomer (E). A network structure is formed by these cross-linkings, and contributes to the improvement of the hardness of the hard coat film according to the present invention.
The reactive functional group a is appropriately selected according to the polyfunctional monomer (B) and the polymer (C). As the reactive functional group a, a polymerizable unsaturated group is suitably used, preferably a photocurable unsaturated group, and particularly preferably an ionizing radiation curable unsaturated group. Specific examples thereof include ethylenically unsaturated bonds such as (meth) acryloyl group, vinyl group and allyl group, and epoxy group.

The coating organic component suppresses the aggregation of silica fine particles and introduces many reactive functional groups into the surface of the silica fine particles to improve the hardness of the film (hard coat layer). It is preferable to coat the whole. From such a viewpoint, the organic component covering the silica fine particles is preferably contained in the reactive silica fine particles (A) in an amount of 1.00 × 10 ⁻³ g / m ² or more. In an aspect in which an organic component is attached to or bonded to the surface of the silica fine particles, the organic component covering the silica fine particles is contained in the reactive silica fine particles (A) at least 2.00 × 10 ⁻³ g / m ^2. It is more preferable that the reactive silica fine particles (A) contain 3.50 × 10 ⁻³ g / m ² or more. In an aspect in which the silica particles are contained in the polymer particles, the organic component covering the silica particles may be contained in the reactive silica particles (A) at 3.50 × 10 ⁻³ g / m ² or more. More preferably, the reactive silica fine particles (A) are particularly preferably contained in an amount of 5.50 × 10 ⁻³ g / m ² or more.

The ratio of the organic component that is coated is usually a constant value of weight loss when the dry powder is completely burned in air, for example, by thermogravimetric analysis from room temperature to 800 ° C. in air. Can be sought.
In addition, the amount of organic components per unit area can be obtained by the following method. First, a value obtained by dividing the organic component weight by the inorganic component weight (organic component weight / inorganic component weight) is measured by differential thermogravimetric analysis (DTG). Next, the volume of the entire inorganic component is calculated from the inorganic component weight and the specific gravity of the silica fine particles used. Further, assuming that the silica fine particles before coating are spherical, the volume per silica fine particle before coating and the surface area are calculated from the average particle diameter of the silica fine particles before coating. Next, the number of reactive silica fine particles (A) is determined by dividing the volume of the entire inorganic component by the volume per silica fine particle before coating. Further, by dividing the organic component weight by the number of reactive silica fine particles (A), the amount of organic component per reactive silica fine particle (A) is determined. Finally, by dividing the weight of the organic component per reactive silica fine particle (A) by the surface area per silica fine particle before coating, the amount of organic component per unit area can be determined.

As a method for preparing reactive silica fine particles (A) having a reactive functional group a introduced on the surface thereof, the organic component being coated on at least a part of the surface, the reactivity desired to be introduced into the silica fine particles A conventionally known method can be appropriately selected and used depending on the functional group a.
In particular, in the present invention, the organic component to be coated can be contained in the reactive silica fine particles (A) at 1.00 × 10 ⁻³ g / m ² or more per unit area of the silica fine particles before coating. Thus, from the viewpoint of suppressing aggregation of the silica fine particles and improving the hardness of the film, it is preferable to select and use any of the following reactive silica fine particles (A) (i) and (ii).
(I) saturated or unsaturated carboxylic acid, acid anhydride, acid chloride, ester and acid amide corresponding to the carboxylic acid, amino acid, imine, nitrile, isonitrile, epoxy compound, amine, β-dicarbonyl compound, silane, And by dispersing silica fine particles in water and / or an organic solvent as a dispersion medium in the presence of one or more surface modification compounds having a molecular weight of 500 or less selected from the group consisting of metal compounds having functional groups. Reactive silica fine particles (A) having a reactive functional group a on the surface.
(Ii) The reactive fine group a introduced into the silica fine particles before coating, the group represented by the following chemical formula (1), and a compound containing a silanol group or a group that generates a silanol group by hydrolysis are bonded to the silica fine particles. Reactive silica fine particles (A) having a reactive functional group a on the surface.
Chemical formula (1)
−Q ¹ −C (= Q ² ) −Q ³ −
In chemical formula (1), Q ¹ represents NH, O (oxygen atom), or S (sulfur atom), Q ² represents O or S, and Q ³ represents NH or a divalent or higher valent organic group. .

Hereinafter, the reactive silica fine particles (A) suitably used in the present invention will be described in order.
(I) saturated or unsaturated carboxylic acid, acid anhydride, acid chloride, ester and acid amide corresponding to the carboxylic acid, amino acid, imine, nitrile, isonitrile, epoxy compound, amine, β-dicarbonyl compound, silane, And by dispersing silica fine particles in water and / or an organic solvent as a dispersion medium in the presence of one or more surface modification compounds having a molecular weight of 500 or less selected from the group consisting of metal compounds having functional groups. Reactive silica fine particles (A) having a reactive functional group a on the surface.
When the reactive silica fine particles (A) of (i) are used, there is an advantage that the film strength can be improved even if the organic component content is small.

  The surface modifying compound used in the reactive silica fine particles (A) of (i) is a carboxyl group, an acid anhydride group, an acid chloride group, an acid amide group, an ester group, an imino group, a nitrile group, an isonitrile group, Hydroxyl group, thiol group, epoxy group, primary, secondary and tertiary amino group, Si—OH group, hydrolyzable residue of silane, C—H acid group such as β-dicarbonyl compound, etc. Having functional groups capable of chemically bonding with the groups present on the surface of the silica fine particles under the dispersion conditions. The chemical bond here preferably includes a covalent bond, an ionic bond or a coordinate bond, but also includes a hydrogen bond. The coordination bond is considered to be complex formation. For example, acidic / base reaction, complex formation or esterification according to Bronsted or Lewis occurs between the functional group of the surface modifying compound and the group on the surface of the silica fine particle. The said surface modification compound used for the reactive silica fine particle (A) of said (i) can be used 1 type or in mixture of 2 or more types.

The surface modifying compound is usually added to the surface modifying compound via the functional group in addition to at least one functional group (hereinafter referred to as the first functional group) that can participate in chemical bonding with the surface group of the silica fine particles. After binding, it has molecular residues that impart new properties to the silica particles. The molecular residue or a part thereof is hydrophobic or hydrophilic and, for example, stabilizes, integrates or activates silica fine particles.
For example, examples of the hydrophobic molecular residue include an alkyl, aryl, alkaryl, aralkyl, or fluorine-containing alkyl group that causes inactivation or repulsion. Examples of the hydrophilic group include a hydroxy group, an alkoxy group, and a polyester group.

  When a reactive functional group a capable of reacting with the polyfunctional monomer (B) and the polymer (C) described later is included in the molecular residue of the surface modification compound, the first included in the surface modification compound. It is possible to introduce the reactive functional group a capable of reacting with the polyfunctional monomer (B) and the polymer (C) onto the surface of the silica fine particle (i) above by reacting the functional group of . For example, in addition to the first functional group, a surface modification compound further having a polymerizable unsaturated group is preferable.

  On the other hand, a second reactive functional group is contained in the molecular residue of the surface modifying compound, and the second reactive functional group is used as a foothold, so that the surface of the silica fine particle of (i) has a large amount. A reactive functional group a capable of reacting with the functional monomer (B) and the polymer (C) may be introduced. For example, a group capable of hydrogen bonding (hydrogen bonding group) such as a hydroxyl group and an oxy group is introduced as the second reactive functional group, and another hydrogen bonding group introduced on the surface of the silica fine particles It is preferable to introduce a reactive functional group a capable of reacting with the polyfunctional monomer (B) and the polymer (C) by the reaction of the hydrogen bond forming group of the surface modification compound. That is, as a surface modification compound, a compound having a hydrogen bond forming group, a reactive functional group a capable of reacting with a polyfunctional monomer (B) such as a polymerizable unsaturated group, and a polymer (C), and a hydrogen bond forming group It is mentioned as a suitable example to use together. Specific examples of the hydrogen bond-forming group indicate a functional group such as a hydroxyl group, a carboxyl group, an epoxy group, a glycidyl group, an amide group, or an amide bond. Here, the amide bond indicates that the bond unit contains —NHC (O) or> NC (O) —. Among the hydrogen bond forming groups used in the surface modification compound of the present invention, among them, a carboxyl group, a hydroxyl group, and an amide group are preferable.

  The surface modifying compound used in the reactive silica fine particles (A) of (i) above has a molecular weight of 500 or less, more preferably 400, especially 200. Since it has such a low molecular weight, it is presumed that the surface of the inorganic fine particles can be rapidly occupied and aggregation of the inorganic fine particles can be prevented.

  The surface modification compound used in the reactive silica fine particles (A) of (i) is preferably a liquid under the reaction conditions for surface modification, and is soluble or at least emulsifiable in a dispersion medium. preferable. Among these, it is preferable that the polymer is dissolved in the dispersion medium and uniformly distributed as discrete molecules or molecular ions in the dispersion medium.

  Saturated or unsaturated carboxylic acids have 1 to 24 carbon atoms, such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, acrylic acid, methacrylic acid, crotonic acid, citric acid, Examples include adipic acid, succinic acid, glutaric acid, oxalic acid, maleic acid, fumaric acid, itaconic acid and stearic acid, and the corresponding acid anhydrides, chlorides, esters and amides such as caprolactam. Further, when an unsaturated carboxylic acid is used, a polymerizable unsaturated group can be introduced.

Examples of preferred amines are those having the chemical formula Q _3-n NH _n (n = 0, 1 or 2), wherein the residue Q is independently 1-12, in particular 1-6, particularly preferably 1- Alkyl having 4 carbon atoms (eg, methyl, ethyl, n-propyl, i-propyl and butyl) and aryl, alkaryl or aralkyl having 6-24 carbon atoms (eg, phenyl, naphthyl, tolyl and benzyl) Represents. Examples of preferred amines include polyalkyleneamines, and specific examples are methylamine, dimethylamine, trimethylamine, ethylamine, aniline, N-methylaniline, diphenylamine, triphenylamine, toluidine, ethylenediamine, and diethylenetriamine. .

Preferred β-dicarbonyl compounds are those having 4 to 12, particularly 5 to 8 carbon atoms, such as diketones (such as acetylacetone), 2,3-hexanedione, 3,5-heptanedione, acetoacetic acid, acetoacetate. Examples include acetic acid-C ₁ -C ₄ -alkyl esters (such as acetoacetic acid ethyl ester), diacetyl and acetonylacetone.
Examples of amino acids include β-alanine, glycine, valine, aminocaproic acid, leucine and isoleucine.

  Preferred silanes are hydrolyzable organosilanes having at least one hydrolyzable group or hydroxy group and at least one non-hydrolyzable residue. Here, examples of the hydrolyzable group include a halogen, an alkoxy group, and an acyloxy group. As the non-hydrolyzable residue, a non-hydrolyzable residue having a reactive functional group a and / or not having a reactive functional group a is used. Silanes having at least partially organic residues substituted with fluorine may also be used.

As the silane used is not particularly limited, for _{example, CH 2 = CHSi (OOCCH 3} ) 3, CH 2 = CHSiCl 3, CH 2 = CHSi (OC 2 H 5) 3, CH 2 = CHSi (OC 2 H _{4 OCH 3) 3, CH 2} = CH-CH 2 -Si (OC 2 H 5) 3, CH 2 = CH-CH 2 -Si (OOCCH 3) 3, γ- glycidyloxypropyltrimethoxysilane (GPTS), γ-glycidyloxypropyldimethylchlorosilane, 3-aminopropyltrimethoxysilane (APTS), 3-aminopropyltriethoxysilane (APTES), N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- [ N '-(2'-aminoethyl) -2-aminoethyl] -3-aminopropyltrimethoxy Sisilane, hydroxymethyltrimethoxysilane, 2- [methoxy (polyethyleneoxy) propyl] trimethoxysilane, bis- (hydroxyethyl) -3-aminopropyltriethoxysilane, N-hydroxyethyl-N-methylaminopropyltriethoxysilane , 3- (meth) acryloxypropyltriethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, and the like.
Such a silane coupling agent is not particularly limited and may include known ones such as KBM-502, KBM-503, KBE-502, KBE-503 (trade names, all of which are Shin-Etsu Chemical Co., Ltd.). Kogyo Co., Ltd.).

As a metal compound which has a functional group, the metal compound of the metal M from 1st group III-V and / or 2nd group II-IV of an element periodic table is mentioned. Zirconium and titanium alkoxides, M (OR) ₄ (M = Ti, Zr), wherein part of the OR group is replaced by a complexing agent such as a β-dicarbonyl compound or a monocarboxylic acid. Can be mentioned. When a compound having a polymerizable unsaturated group (such as methacrylic acid) is used as a complexing agent, a polymerizable unsaturated group can be introduced.

As the dispersion medium, water and / or an organic solvent is preferably used. A particularly preferred dispersion medium is distilled (pure) water. As the organic solvent, polar, nonpolar and aprotic solvents are preferred. Examples thereof include alcohols such as aliphatic alcohols having 1 to 6 carbon atoms (especially methanol, ethanol, n (normal)-and i (iso) -propanol and butanol), methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, acetone and Ketones such as butanone, esters such as ethyl acetate; ethers such as diethyl ether, tetrahydrofuran and tetrahydropyran; amides such as dimethylacetamide and dimethylformamide; sulfoxides and sulfones such as sulfolane and dimethyl sulfoxide; and pentane; Aliphatic (optionally halogenated) hydrocarbons such as hexane and cyclohexane. These dispersion media can be used as a mixture.
The dispersion medium preferably has a boiling point that can be easily removed by distillation (optionally under reduced pressure), and a solvent having a boiling point of 200 ° C. or lower, particularly 150 ° C. or lower is preferable.

  In preparing the reactive silica fine particles (A) of (i), the concentration of the dispersion medium is not particularly limited, and is usually 40 to 90, preferably 50 to 80, particularly 55 to 75% by weight. The rest of the dispersion is composed of untreated inorganic fine particles and the surface modifying compound. Here, the weight ratio of the inorganic fine particles / surface modification compound is preferably 100: 1 to 4: 1, more preferably 50: 1 to 8: 1, and even more preferably 25: 1 to 10: 1. .

  The preparation of the reactive silica fine particles (A) of (i) is preferably performed at room temperature (about 20 ° C.) to the boiling point of the dispersion medium. Particularly preferably, the dispersion temperature is 50 to 100 ° C. The dispersion time depends in particular on the type of material used, but is generally a few minutes to a few hours, for example 1 to 24 hours.

(Ii) a reactive functional group a to be introduced into the silica fine particles before coating, a group represented by the following chemical formula (1), a compound containing a silanol group or a group that generates a silanol group by hydrolysis, and a silica fine particle as a core; Reactive silica fine particles (A) having a reactive functional group a on the surface, obtained by bonding the.
Chemical formula (1)
−Q ¹ −C (= Q ² ) −Q ³ −
In chemical formula (1), Q ¹ represents NH, O (oxygen atom), or S (sulfur atom), Q ² represents O or S, and Q ³ represents NH or a divalent or higher valent organic group. .
When the reactive silica fine particles (A) of (ii) are used, there are advantages that the amount of organic components is increased, and dispersibility and film strength are further increased.

First, a compound containing a reactive functional group a to be introduced into silica fine particles before coating, a group represented by the above chemical formula (1), and a silanol group or a group that generates a silanol group by hydrolysis (hereinafter referred to as reactive functional group-modified hydrolysis). The case may be referred to as decomposable silane).
In the reactive functional group-modified hydrolyzable silane, the reactive functional group a desired to be introduced into the silica fine particles is not particularly limited as long as it is appropriately selected so that it can react with the polyfunctional monomer (B) and polymer (C) described later. . Suitable for introducing polymerizable unsaturated groups as described above.

In the reactive functional group-modified hydrolyzable silane, the [—Q ¹ —C (═Q ² ) —] moiety of the group represented by the chemical formula (1) is specifically [—O—C (═O )-], [-OC (= S)-], [-SC (= O)-], [-NH-C (= O)-], [-NH-C (= S)- ] And [-S-C (= S)-]. These groups can be used individually by 1 type or in combination of 2 or more types. Among them, from the viewpoint of thermal stability, at least of a [—O—C (═O) —] group, a [—O—C (═S) —] group, and a [—S—C (═O) —] group. It is preferable to use one type in combination. The group [—Q ¹ —C (= Q ² ) —Q ³ —] represented by the chemical formula (1) generates an appropriate cohesive force due to hydrogen bonding between molecules, and has excellent mechanical properties when formed into a cured product. It is considered that properties such as strength, adhesion to a substrate and heat resistance can be imparted.

  Examples of the group that generates a silanol group by hydrolysis include groups having an alkoxy group, an aryloxy group, an acetoxy group, an amino group, a halogen atom, etc. on the silicon atom. An oxysilyl group is preferred. A silanol group or a group that forms a silanol group by hydrolysis can be combined with the metal oxide fine particles by a condensation reaction or a condensation reaction that occurs following hydrolysis.

  Preferable specific examples of the reactive functional group-modified hydrolyzable silane include compounds represented by the following chemical formulas (2) and (3). It is preferable to use the compound represented by the chemical formula (3) from the viewpoint of excellent hardness.

In the chemical formulas (2) and (3), R ^a and R ^b may be the same or different, and are a hydrogen atom or a C ₁ to C ₈ alkyl group or aryl group, for example, methyl, ethyl, propyl, Examples thereof include butyl, octyl, phenyl and xylyl groups. Here, m is 1, 2 or 3.
Examples of the group represented by [(R ^a O) _m R ^b _3-m Si—] include a trimethoxysilyl group, a triethoxysilyl group, a triphenoxysilyl group, a methyldimethoxysilyl group, and a dimethylmethoxysilyl group. Can be mentioned. Of these groups, a trimethoxysilyl group or a triethoxysilyl group is preferable.

In the chemical formulas (2) and (3), R ^c is a divalent organic group having a C ₁ to C ₁₂ aliphatic or aromatic structure, and may contain a chain, branched or cyclic structure. . Examples of such an organic group include methylene, ethylene, propylene, butylene, hexamethylene, cyclohexylene, phenylene, xylylene, and dodecamethylene. Among these, preferred examples are methylene, propylene, cyclohexylene, phenylene and the like.

In the chemical formula (2), R ^d is a divalent organic group and is usually selected from divalent organic groups having a molecular weight of 14 to 10,000, preferably a molecular weight of 76 to 500. For example, chain polyalkylene groups such as hexamethylene, octamethylene, dodecamethylene; alicyclic or polycyclic divalent organic groups such as cyclohexylene and norbornylene; divalent groups such as phenylene, naphthylene, biphenylene and polyphenylene Aromatic group; and these alkyl group-substituted and aryl group-substituted products. In addition, these divalent organic groups may contain an atomic group containing an element other than carbon and hydrogen atoms, and include a polyether bond, a polyester bond, a polyamide bond, a polycarbonate bond, and a group represented by the chemical formula (1). Can also be included.

In the chemical formulas (2) and (3), R ^e is an (n + 1) -valent organic group, and is preferably selected from a chain, branched or cyclic saturated hydrocarbon group and unsaturated hydrocarbon group.

  In the chemical formulas (2) and (3), Y ′ represents a monovalent organic group having a reactive functional group a. The reactive functional group a itself as described above may be used. For example, when the reactive functional group a is selected from a polymerizable unsaturated group, a (meth) acryloyl (oxy) group, a vinyl (oxy) group, a propenyl (oxy) group, a butadienyl (oxy) group, a styryl (oxy) group Ethynyl (oxy) group, cinnamoyl (oxy) group, maleate group, (meth) acrylamide group and the like. N is preferably a positive integer of 1 to 20, more preferably 1 to 10, particularly preferably 1 to 5.

  For the synthesis of the reactive functional group-modified hydrolyzable silane used in the present invention, for example, a method described in JP-A-9-100111 can be used. That is, for example, when it is desired to introduce a polymerizable unsaturated group, (i) it is carried out by an addition reaction of a mercaptoalkoxysilane, a polyisocyanate compound, and an active hydrogen group-containing polymerizable unsaturated compound capable of reacting with an isocyanate group. it can. Further, (b) the reaction can be carried out by a direct reaction between a compound having an alkoxysilyl group and an isocyanate group in the molecule and an active hydrogen group-containing polymerizable unsaturated compound. Furthermore, (c) it can also be directly synthesized by an addition reaction of a compound having a polymerizable unsaturated group and an isocyanate group in the molecule with mercaptoalkoxysilane or aminosilane.

  In the production of the reactive silica fine particles (A) of (ii), a method of separately hydrolyzing the reactive functional group-modified hydrolyzable silane, and then mixing this with the silica fine particles, followed by heating and stirring operations Or a method of hydrolyzing a reactive functional group-modified hydrolyzable silane in the presence of silica fine particles, and other components such as polyunsaturated organic compounds, monounsaturated organic compounds, radiation polymerization initiators, etc. A method of performing surface treatment of the silica fine particles in the presence of can be selected, but a method of hydrolyzing the reactive functional group-modified hydrolyzable silane in the presence of silica fine particles is preferable. When the reactive silica fine particles (A) (ii) are produced, the temperature is usually 20 ° C. or higher and 150 ° C. or lower, and the treatment time is in the range of 5 minutes to 24 hours.

  In order to accelerate the hydrolysis reaction, an acid, salt or base may be added as a catalyst. Suitable acids include organic acids and unsaturated organic acids; examples of bases include tertiary amines or quaternary ammonium hydroxides. The amount of the acid or base catalyst added is 0.001 to 1.0% by weight, preferably 0.01 to 0.1% by weight, based on the reactive functional group-modified hydrolyzable silane.

  As the reactive silica fine particles (A), powdery fine particles not containing a dispersion medium may be used. However, it is possible to omit the dispersion step and to use fine particles as a solvent dispersion sol from the viewpoint of high productivity. preferable.

(Polyfunctional monomer (B))
The polyfunctional monomer (B) used in the first curable resin composition is one of the components that are cured to become the matrix of the first hard coat layer, and the reactivity of the reactive silica fine particles (A). It has crosslinking reactivity with the functional group a, the reactive functional group c of the polymer (C) described later, the reactive functional group d of the reactive silica fine particles (D), and the reactive functional group e of the polyfunctional monomer (E). It has 3 or more reactive functional groups b and a molecular weight of 1000 or less. Moreover, the reactive functional group b has cross-linking reactivity with other reactive functional groups b. When cured, the reactive functional groups b and different types of reactive functional groups are cross-linked to form a network structure, which further increases the hardness of the hard coat film. Moreover, since the polyfunctional monomer (B) has a molecular weight as small as 1000 or less and has 3 or more reactive functional groups b, it has a function of increasing the crosslinking density in the hard coat layer and imparting hardness to the hard coat layer. In addition, since the curing speed is high, the production line speed can be improved. It is also effective in improving the adhesion between adjacent layers. When the transparent substrate film is triacetylcellulose (TAC), the adhesion with the TAC substrate can also be improved.
As the reactive functional group b, a polymerizable unsaturated group is suitably used, preferably a photocurable unsaturated group, and particularly preferably an ionizing radiation curable unsaturated group. Specific examples thereof include ethylenically unsaturated bonds such as (meth) acryloyl group, vinyl group and allyl group, and epoxy group.

  The reactive functional group b may be the same as or different from the reactive functional group a. The reactive functional group b of the polyfunctional monomer (B) is 3 or more, but preferably 6 or more. If the number is less than 2, the hardness of the hard coat film becomes insufficient, and the adhesion with the adjacent second hard coat layer is poor, and even if it adheres, heat resistance test, heat resistance test, light test, etc. This is not preferable because the adhesiveness deteriorates in the environmental test.

  The molecular weight of the polyfunctional monomer (B) is 1000 or less. When the molecular weight exceeds 1000, the hardness of the hard coat layer is undesirably lowered.

  As the polyfunctional monomer (B), one or two or more binder components can be used.

Examples of the polyfunctional monomer (B) include pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, trimethylolpropane tri (meth) acrylate, and trimethylolpropane hexa. Examples include (meth) acrylates and modified products thereof.
Examples of modified products include EO (ethylene oxide) modified products, PO (propylene oxide) modified products, CL (caprolactone) modified products, and isocyanuric acid modified products.
In the polyfunctional monomer (B), acrylate is preferable to methacrylate from the viewpoint of curing reactivity.

  As the polyfunctional monomer (B), pentaerythritol triacrylate (PETA) and dipentaerythritol hexaacrylate (DPHA) are particularly preferably used.

  The content of the polyfunctional monomer (B) and the polymer (C) to be described later is such that the ratio (weight ratio) of the content of polyfunctional monomer (B): polymer (C) in the first curable resin composition is 20 : It is preferable that it is 80-80: 20. If it is this range, high hardness, the favorable curl reduction effect, moderate softness | flexibility, and a restoring property can be provided to a 1st hard-coat layer.

(Polymer (C))
The polymer (C) is a component that becomes a matrix of the first hard coat layer together with the polyfunctional monomer (B) when cured, the reactive functional group a of the reactive silica fine particles (A), the polyfunctional monomer Reactive functional group b of (B), reactive functional group d of reactive silica fine particles (D) described later, and reactive functional group c having crosslinking reactivity with reactive functional group e of polyfunctional monomer (E) 30 or more in the molecular side chain, and the weight average molecular weight is 10,000 to 50,000. In addition, the reactive functional group c has cross-linking reactivity with other reactive functional groups c. Similar to the polyfunctional monomer (B), when it is cured, the reactive functional groups c and different types of reactive functional groups are cross-linked to form a network structure, which further increases the hardness of the hard coat film. In addition, the polymer (C) has an effect of reducing curling of the hard coat film according to the present invention and an effect of suppressing cracking of the hard coat layer.
As the reactive functional group c, a polymerizable unsaturated group is suitably used, preferably a photocurable unsaturated group, and particularly preferably an ionizing radiation curable unsaturated group. Specific examples thereof include ethylenically unsaturated bonds such as (meth) acryloyl group, vinyl group and allyl group, and epoxy group.

  The polymer (C) is preferably a curable organic resin, preferably a translucent material that transmits light when formed into a coating film, and an ionizing radiation cured resin that is cured by ionizing radiation represented by ultraviolet rays or electron beams. A suitable resin or other known curable resin may be employed depending on the required performance. Examples of the ionizing radiation curable resin include acrylate-based, oxetane-based, and silicone-based resins.

  Examples of the polymer (C) include a polymer represented by the following chemical formula (4) having a molecular weight of 10,000 to 50,000.

化学式（４）中、Ｘは直鎖、分枝、又は環状の炭化水素鎖が単独又は組み合わされてなり、当該炭化水素鎖は置換基を有していても良く、また当該炭化水素鎖間には異種原子が含まれていても良い、前記置換基を除いた価数が３価の有機基である。Ｙは反応性官能基ｃ又は１つ以上の反応性官能基ｃを有する化合物残基を表す。Ｄは炭素数１〜１０の連結基を表し、ｑは０又は１を表す。Ｅは任意のビニルモノマーの重合単位を表し、単一成分であっても複数の成分で構成されていてもよい。ｏ、ｐは各重合単位のモル％である。ｐは０であっても良い。

In the chemical formula (4), X is a linear, branched, or cyclic hydrocarbon chain, which is used alone or in combination, and the hydrocarbon chain may have a substituent, and between the hydrocarbon chains. Is an organic group having a trivalent valence excluding the substituent, which may contain different atoms. Y represents a compound residue having a reactive functional group c or one or more reactive functional groups c. D represents a linking group having 1 to 10 carbon atoms, and q represents 0 or 1. E represents a polymerization unit of an arbitrary vinyl monomer, and may be composed of a single component or a plurality of components. o and p are mol% of each polymerized unit. p may be 0.

  In the chemical formula (4), X is a linear, branched, or cyclic hydrocarbon chain, either alone or in combination. The hydrocarbon chain may have a substituent, and between the hydrocarbon chains. May contain a heteroatom, and is a trivalent organic group excluding the substituent.

The hydrocarbon chain includes a saturated hydrocarbon such as —CH ₂ — or an unsaturated hydrocarbon such as —CH═CH—. The cyclic hydrocarbon chain may be composed of an alicyclic compound or may be composed of an aromatic compound. Further, different atoms such as O and S may be included between the hydrocarbon chains, and ether bonds, thioether bonds, ester bonds, urethane bonds, and the like may be included between the hydrocarbon chains. In addition, the hydrocarbon chain branched via a different atom with respect to a linear or cyclic hydrocarbon chain is counted as the carbon number of the substituent mentioned later.

  Specific examples of the substituent that the hydrocarbon chain may have include a halogen atom, a hydroxyl group, a carboxyl group, an amino group, an epoxy group, an isocyanate group, a mercapto group, a cyano group, a silyl group, a silanol group, and a nitro group. Group, acetyl group, acetoxy group, sulfone group and the like are mentioned, but not particularly limited. Substituents that may be present in the hydrocarbon chain include hydrocarbon chains that are branched via a hetero atom with respect to a linear or cyclic hydrocarbon chain as described above. A group (RO-, where R is a saturated or unsaturated linear, branched, or cyclic hydrocarbon chain), an alkylthioether group (RS-, where R is a saturated or unsaturated linear chain, A branched or cyclic hydrocarbon chain), an alkyl ester group (RCOO-, where R is a saturated or unsaturated linear, branched, or cyclic hydrocarbon chain). .

Y independently represents a reactive functional group c or a compound residue having one or more reactive functional groups c.
When Y is the reactive functional group c itself, examples of Y include polymerizable unsaturated groups such as vinyl group (CH ₂ ═CH—) and (meth) acryloyl group.

Examples of the reactive functional group c in the case where Y is a compound residue having one or more reactive functional groups c include, for example, a (meth) acryloyloxy group, CH ₂ = CR- (where R is a hydrocarbon Polymerizable unsaturated groups such as a group). The reactive silica fine particles (A), the polyfunctional monomer (B), the reactive silica fine particles (D) contained in the second curable resin composition, and the polyfunctional monomer (E) may be appropriately reacted. If the reactive functional group c is selected, the compound residue is not particularly limited. When Y is a compound residue, the number of reactive functional groups c possessed by Y may be one, but two or more can further increase the crosslink density, and the first curable resin composition This is preferable from the viewpoint of hardness when the product is cured to form the first hard coat layer.

In the case where Y is a compound residue having one or more reactive functional groups c, the compound residues are further subjected to reactive substitution separately from at least one reactive functional group c and the reactive functional group c. It is a residue obtained by removing the reactive substituent or a part of the reactive substituent (such as hydrogen) from a compound having a group.
For example, as the compound residue having an ethylenically unsaturated group, specifically, for example, a reactive substituent other than the ethylenically unsaturated group of the following compound or a part of the reactive substituent (such as hydrogen) is excluded. Residue. Examples include (meth) acrylic acid, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and pentaerythritol tri (meth) acrylate, but are not limited thereto.

  As the reactive functional group c, an acrylate group is preferable to a methacrylate group from the viewpoint of curing reactivity.

  D in the chemical formula (4) represents a linking group having 1 to 10 carbon atoms, more preferably a linking group having 1 to 6 carbon atoms, particularly preferably a linking group having 2 to 4 carbon atoms, which is linear. May have a branched structure, may have a ring structure, and may have a heteroatom selected from O, N, and S.

Preferred examples of the linking group D in the chemical formula (4) include * — (CH ₂ ) ₂ —O — **, * — (CH ₂ ) ₂ —NH — **, * — (CH ₂ ) ₄ —O. _{- **, * - (CH 2} ) 6 -O - **, * - (CH 2) 2 -O- (CH) 2 -O - **, * - CONH- (CH 2) 3 -O- * *, * —CH ₂ CH (OH) CH ₂ —O — **, * —CH ₂ CH ₂ OCONH (CH ₂ ) ₃ —O — ** and the like. Here, * represents a connecting site on the polymer main chain side, and ** represents a connecting site on the (meth) acryloyl group side.
In addition, the linking group D may include an ester bond.

  In chemical formula (4), E represents a polymerization unit of an arbitrary vinyl monomer, and there is no particular limitation as long as the polymer (C) satisfies the weight average molecular weight of 10,000 to 50,000, and hardness, solubility in a solvent, and transparency It can be suitably selected from various viewpoints such as properties, and may be composed of a single or a plurality of vinyl monomers depending on the purpose.

  Examples of the polymerization unit E include methyl vinyl ether, ethyl vinyl ether, t-butyl vinyl ether, cyclohexyl vinyl ether, isopropyl vinyl ether, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, glycidyl vinyl ether, vinyl ethers such as allyl vinyl ether, vinyl acetate, and vinyl propionate. , Vinyl esters such as vinyl butyrate, methyl (meth) acrylate, ethyl (meth) acrylate, hydroxyethyl (meth) acrylate, glycidyl methacrylate, allyl (meth) acrylate, (meth) acryloyloxypropyltrimethoxysilane ( (Meth) acrylates, styrene, styrene derivatives such as p-hydroxymethylstyrene, crotonic acid, maleic acid, italy Unsaturated carboxylic acids and derivatives thereof such as phosphate and the like.

  In chemical formula (4), o may be 100 mol%, that is, a single polymer. Moreover, even if o is 100 mol%, the copolymer in which 2 or more types of polymerization units containing the (meth) acryloyl group represented by o mol% were used may be used. The ratio of o and p is not particularly limited as long as the number of reactive functional groups c is 30 or more, and can be appropriately selected from various viewpoints such as hardness, solubility in a solvent, and transparency.

  As the polymer (C), commercially available products may be used. Examples of the commercially available products include Arakawa Chemical Industries, Ltd., Beam Set 371, Beam Set 371MLV, Beam Set DK1, Beam Set DK2, Beam Set DK3. Hitachi Chemical Co., Ltd., Hitachioid 7975D5, 7975D12, etc. can be mentioned.

  The content of the polyfunctional monomer (B) and the polymer (C) is such that the ratio (weight ratio) of the content of the polyfunctional monomer (B): polymer (C) in the first curable resin composition is 20: It is preferable that it is 80-80: 20. If it is this range, high hardness, the favorable curl reduction effect, moderate softness | flexibility, and a restoring property can be provided to a 1st hard-coat layer.

(Other ingredients)
In addition to the above components, a solvent, a polymerization initiator, an antistatic agent, and an antiglare agent can be appropriately added to the first curable resin composition. Furthermore, various additives, such as a reactive or non-reactive leveling agent and various sensitizers, may be mixed. In the case of containing an antistatic agent and / or an antiglare agent, antistatic properties and / or antiglare properties can be further imparted to the first hard coat layer of the present invention.

(solvent)
Specific examples of the solvent include methanol, ethanol, normal propanol, isopropanol (IPA), normal butanol, sec-butanol, isobutanol, tert-butanol, methyl glycol, propylene glycol monomethyl ether (PGME), methyl glycol acetate, methyl cellosolve. , Alcohols such as ethyl cellosolve, butyl cellosolve; ketones such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), cyclohexanone, diacetone alcohol; methyl formate, methyl acetate, ethyl acetate, ethyl lactate, butyl acetate, etc. Esters; nitrogen-containing compounds such as nitromethane, N-methylpyrrolidone, N, N-dimethylformamide; diisopropyl ether, tetrahydrofuran , Dioxane, dioxolane and the like; methylene chloride, chloroform, trichloroethane, halogenated hydrocarbons such as tetrachloroethane; dimethylsulfoxide, other objects, such as propylene carbonate; or mixtures thereof.
It is one or more impermeable solvents selected from the group consisting of MIBK, PGME, normal propanol, isopropanol, normal butanol, sec-butanol, isobutanol, and tert-butanol from the viewpoint of improving the hardness of the hard coat film. It is preferable. By using a non-permeable solvent, the polyfunctional monomer (B) and the polymer (C) do not penetrate into the transparent substrate film, and thus the hardness of the first hard coat layer can be increased.
In addition, in this invention, osmosis | permeation means dissolving or swelling a transparent base film.

(Polymerization initiator)
In the present invention, in order to initiate or promote the radical polymerizable functional group or the cationic polymerizable functional group, a radical polymerization initiator, a cationic polymerization initiator, a radical and a cationic polymerization initiator are appropriately selected as necessary. May be used. These polymerization initiators are decomposed by light irradiation and / or heating to generate radicals or cations to advance radical polymerization and cationic polymerization.

Any radical polymerization initiator may be used as long as it can release a substance that initiates radical polymerization by light irradiation and / or heating. For example, examples of the photo radical polymerization initiator include imidazole derivatives, bisimidazole derivatives, N-aryl glycine derivatives, organic azide compounds, titanocenes, aluminate complexes, organic peroxides, N-alkoxypyridinium salts, thioxanthone derivatives, and the like. More specifically, 1,3-di (tert-butyldioxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetrakis (tert-butyldioxycarbonyl) benzophenone, 3-phenyl-5- Isoxazolone, 2-mercaptobenzimidazole, bis (2,4,5-triphenyl) imidazole, 2,2-dimethoxy-1,2-diphenylethane-1-one (trade name Irgacure 651, Ciba Japan Co., Ltd.) 1-hydroxy-cyclohexyl-phenyl- T (trade name Irgacure 184, manufactured by Ciba Japan Co., Ltd.), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one (trade names Irgacure 369, Ciba Japan ( Co., Ltd.), bis (η ⁵ -2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium) (trade name Irgacure 784, manufactured by Ciba Japan Co., Ltd.), etc., but is not limited thereto.

Moreover, the cationic polymerization initiator should just be able to discharge | release the substance which starts cationic polymerization by light irradiation and / or a heating. Examples of the cationic polymerization initiator include sulfonic acid ester, imide sulfonate, dialkyl-4-hydroxysulfonium salt, arylsulfonic acid-p-nitrobenzyl ester, silanol-aluminum complex, (η ⁶ -benzene) (η ⁵ -cyclopentadidiene). Enyl) iron (II) and the like are exemplified, and more specifically, benzoin tosylate, 2,5-dinitrobenzyl tosylate, N-tosiphthalimide and the like are exemplified, but not limited thereto.

  Examples of radical polymerization initiators that can be used as cationic polymerization initiators include aromatic iodonium salts, aromatic sulfonium salts, aromatic diazonium salts, aromatic phosphonium salts, triazine compounds, iron arene complexes, and the like. More specifically, iodonium chloride such as diphenyliodonium, ditolyliodonium, bis (p-tert-butylphenyl) iodonium, bis (p-chlorophenyl) iodonium, bromide, borofluoride, hexafluorophosphate salt, hexafluoro Iodonium salts such as antimonate salts, chlorides of sulfonium such as triphenylsulfonium, 4-tert-butyltriphenylsulfonium, tris (4-methylphenyl) sulfonium, bromides, borofluorides, hexaf Sulfonium salts such as orophosphate salts and hexafluoroantimonate salts, 2,4,6-tris (trichloromethyl) -1,3,5-triazine, 2-phenyl-4,6-bis (trichloromethyl) -1, 2,4,6-substituted-1,3,5 triazine compounds such as 3,5-triazine, 2-methyl-4,6-bis (trichloromethyl) -1,3,5-triazine, etc. It is not limited to these.

(Antistatic agent)
Specific examples of the antistatic agent include quaternary ammonium salts, pyridinium salts, various cationic compounds having cationic groups such as primary to tertiary amino groups, sulfonate groups, sulfate ester bases, and phosphate ester bases. , Anionic compounds having an anionic group such as phosphonate group, amphoteric compounds such as amino acid series and aminosulfate ester series, nonionic compounds such as amino alcohol series, glycerin series and polyethylene glycol series, and alkoxides of tin and titanium And metal chelate compounds such as acetylacetonate salts thereof, and compounds obtained by increasing the molecular weight of the compounds listed above. In addition, it has a tertiary amino group, a quaternary ammonium group, or a metal chelate portion, and has a monomer or oligomer that can be polymerized by ionizing radiation, or a polymerizable functional group that can be polymerized by ionizing radiation, and Polymerizable compounds such as organometallic compounds such as coupling agents can also be used as antistatic agents.

Moreover, electroconductive fine particles are mentioned as another example of the said antistatic agent. Specific examples of the conductive fine particles include those made of a metal oxide. Examples of such metal oxides include ZnO (refractive index 1.90, the numerical value in parentheses below represents the refractive index), CeO ₂ (1.95), Sb ₂ O ₂ (1.71), SnO. ₂ (1.997), indium tin oxide (1.95) often referred to as ITO, In ₂ O ₃ (2.00), Al ₂ O ₃ (1.63), antimony-doped tin oxide (abbreviation) ATO, 2.0), aluminum-doped zinc oxide (abbreviation: AZO, 2.0), and the like. The conductive fine particles preferably have an average particle size of 0.1 nm to 0.1 μm. By being within such a range, when the conductive fine particles are dispersed in a binder, a composition capable of forming a highly transparent film having almost no haze and good total light transmittance can be obtained.

(Anti-glare agent)
Examples of the antiglare agent include fine particles, and the shape of the fine particles may be a true sphere or an ellipse, and preferably a true sphere. The fine particles may be inorganic or organic, but those formed of an organic material are preferred. The fine particles exhibit anti-glare properties and are preferably transparent. Specific examples of the fine particles include plastic beads, and more preferably those having transparency. Specific examples of plastic beads include styrene beads (refractive index 1.59), melamine beads (refractive index 1.57), acrylic beads (refractive index 1.49), acrylic-styrene beads (refractive index 1.54), Examples thereof include polycarbonate beads and polyethylene beads. The addition amount of the fine particles is about 2 to 30 parts by weight, preferably about 10 to 25 parts by weight with respect to 100 parts by weight of the resin composition.
The measurement of the refractive index is not particularly limited, and a conventionally known method can be used. For example, a method of calculating from a reflectance curve measured with a spectrophotometer using a simulation, a method of measuring using an ellipsometer, and an Abbe method can be mentioned.

3. Second hard coat layer The second hard coat layer of the present invention comprises reactive silica fine particles (D) having an average particle diameter of 10 to 100 nm having reactive functional groups d on the particle surfaces, and reactive functional groups e. The reactive silica fine particles (D) are composed of a cured product of the second curable resin composition containing a polyfunctional monomer (E) having 3 or more in one molecule and a molecular weight of 1000 or less. It is contained in an amount of 0 to 30% by weight based on the total solid content of the curable resin composition. Thereby, the second hard coat layer has appropriate flexibility.

  The second hard coat layer has a thickness of 20 μm or less, a Vickers hardness of 53 to 69 Hv, and an absolute value of a difference from the Vickers hardness of the first hard coat layer is 13 or less.

  The method for obtaining the Vickers hardness of the second hard coat layer is the second curable resin composition in place of the first curable resin composition in the method for measuring the Vickers hardness of the first hard coat layer. The second hard coat layer is formed using the product, and the Vickers hardness test is similarly performed three times to obtain the average value.

  The film thickness of the second hard coat layer is 20 μm or less, preferably 0.5 to 18 μm, and more preferably 1 to 18 μm from the viewpoint of scratch resistance.

  The reactive silica fine particles (D) and the polyfunctional monomer (E) and other components such as a solvent used as necessary and a polymerization initiator contained in the second curable resin composition are The same curable resin composition can be used.

  Similar to the reactive silica fine particles (A), the reactive silica fine particles (D) may be used not only having a single average particle diameter but also a combination of two or more kinds having different average particle diameters. When two or more kinds are used in combination, the average particle diameter of each reactive silica fine particle (D) is within 10 to 100 nm and the total weight% of each reactive silica fine particle (D) is the second curable resin composition. It may be 0% by weight or more and less than 30% by weight with respect to the total solid content.

  The reactive silica fine particles (A) and the reactive silica fine particles (D) may be the same or different.

As the polyfunctional monomer (E), one or more monomers can be used as in the polyfunctional monomer (B).
As the second binder component, pentaerythritol triacrylate and dipentaerythritol hexaacrylate are particularly preferably used.
The polyfunctional monomer (B) and the polyfunctional monomer (E) may be the same or different.

  The solvent which is the other component of the second curable resin composition may be non-permeable or permeable, and may be used in combination.

  Other components such as a polymerization initiator of the second curable resin composition may be the same as or different from those of the first curable resin composition.

4). Other Layers The hard coat film according to the present invention is basically composed of the transparent base film, the first hard coat layer, and the second hard coat layer as described above. However, in consideration of the function or use as a hard coat film, in addition to the first and second hard coat layers, one or more of the following layers may be added to the first hard coat layer. You may provide in the surface on the opposite side to this hard-coat layer.

4-1. Antistatic layer The antistatic layer comprises a cured product of a curable resin composition for an antistatic layer containing an antistatic agent and a curable resin. The thickness of the antistatic layer is preferably about 30 nm to 1 μm.

  As the antistatic agent, the same antistatic agents as those mentioned for the antistatic agent of the first hard coat layer can be used.

  As a curable resin contained in the curable resin composition for an antistatic layer, a known resin can be appropriately selected and used alone or in combination of two or more.

4-2. Antiglare layer The antiglare layer is made of a cured product of a curable resin composition for an antiglare layer containing an antiglare agent and a curable resin. As the curable resin, a known resin can be appropriately selected, and one kind or two or more kinds can be used.

(Anti-glare agent)
As the antiglare agent, the same antiglare agents as those described above for the first hard coat layer can be used.

4-3. Antifouling layer According to a preferred embodiment of the present invention, an antifouling layer may be provided for the purpose of preventing dirt on the outermost surface of the hard coat film. The antifouling layer can further improve the antifouling property and scratch resistance of the hard coat film. The antifouling layer comprises a cured product of a curable resin composition for an antifouling layer comprising an antifouling agent and a curable resin composition.

  The antifouling agent and curable resin contained in the curable resin composition for the antifouling layer can be appropriately selected from known antifouling agents and curable resins, and one or more can be used.

4-4. Low Refractive Index Layer The low refractive index layer is a layer having a refractive index lower than that of the layer adjacent to the transparent base film side of the layer, and is made of a cured product of the curable resin composition for the low refractive index layer. In the curable resin composition for a low refractive index layer, a known low refractive index curable resin or fine particles can be appropriately used so that the refractive index is lower than that of the adjacent layer.

FIG. 5 is a cross-sectional view schematically showing another example of the layer configuration of the hard coat film according to the present invention.
A first hard coat layer 20, a second hard coat layer 30, and an antistatic layer 50 are provided on one side of the transparent base film 10 in order from the side close to the transparent base film. Each of the first hard coat layer 20 and the second hard coat layer 30 has a Vickers hardness of 53 to 69 Hv, and the absolute value of the difference between the two layers of Vickers hardness is 13 or less.
FIG. 6 is a cross-sectional view schematically showing another example of the layer configuration of the hard coat film according to the present invention.
A first hard coat layer 20, a second hard coat layer 30, an antistatic layer 50 and a low refractive index layer 60 are provided on one side of the transparent base film 10 in order from the side close to the transparent base film. Yes. Each of the first hard coat layer 20 and the second hard coat layer 30 has a Vickers hardness of 53 to 69 Hv, and the absolute value of the difference between the two layers of Vickers hardness is 13 or less.

II. Method for producing hard coat film (Preparation of first and second curable resin compositions)
The first and second curable resin compositions of the present invention are usually prepared by mixing and dispersing the above components in a solvent according to a general preparation method. A paint shaker or a bead mill can be used for mixing and dispersing.

(Formation of hard coat layer)
The first curable resin composition is applied onto a transparent substrate film and dried.
The coating method is not particularly limited as long as the first curable resin composition can be uniformly coated on the surface of the transparent base film, and is not limited to spin coating, dipping, spraying, slides. Various methods such as a coating method, a bar coating method, a roll coater method, a meniscus coater method, a flexographic printing method, a screen printing method, and a speed coater method can be used.
The coating amount on the transparent substrate film varies depending on the performance required for the obtained hard coat film, but the coating amount after drying ranges from 1 g / m ^{2 to} 30 g / m ² . among them, particularly preferably in the range of ^{5g / m 2 ~25g / m 2} .

  Examples of the drying method include reduced-pressure drying or heat drying, and a method combining these drying methods. For example, when a ketone solvent is used as the solvent, it is usually dried at a temperature in the range of room temperature to 80 ° C., preferably 40 ° C. to 60 ° C., for 20 seconds to 3 minutes, preferably 30 seconds to 1 minute. A process is performed.

Next, the coating film obtained by applying and drying the first curable resin composition is irradiated and / or heated according to the reactive functional group contained in the first curable resin composition. By curing the coating film, the reactive functional group a of the reactive silica fine particles (A) and the reactive functionality of the polyfunctional monomer (B) contained in the constituent components of the first curable resin composition The group b and the reactive functional group c of the polymer (C) are cross-linked to form a first hard coat layer made of a cured product of the first curable resin composition.
For light irradiation, ultraviolet rays, visible light, electron beams, ionizing radiation, etc. are mainly used. In the case of ultraviolet curing, ultraviolet rays emitted from light such as an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a xenon arc, and a metal halide lamp are used. The irradiation amount of the energy ray source is about 50 to 5000 mJ / cm ² as an integrated exposure amount at an ultraviolet wavelength of 365 nm.
When heating, it processes at the temperature of 40 to 120 degreeC normally. Moreover, you may react by leaving it to stand for 24 hours or more at room temperature (25 degreeC).

  After forming the first hard coat layer, the second curable resin composition is applied onto the first hard coat layer in the same manner as the first curable resin composition, dried, irradiated with light, and / or heated. Then, the second hard coat layer is formed by drying the coating film to obtain the hard coat film of the present invention.

Before the first curable resin composition is applied and the first hard coat layer is completely formed, that is, the first hard coat layer is half-cured (semi-cured), The second curable resin composition is applied onto the hard coat layer, dried, and the first hard coat layer and the second hard coat layer are simultaneously irradiated with light and / or heated to be fully cured. The hard coat film of the present invention may be obtained. The integrated exposure amount when half-curing is about 5 to 50 mJ / cm ² .

(Formation of other layers)
When the other functional layer such as an antistatic layer is provided on the surface of the second hard coat layer opposite to the first hard coat layer, the curable resin composition is applied in the same manner as the hard coat layer. The functional layer may be provided by drying, light irradiation and / or heating.

Hereinafter, the present invention will be described more specifically with reference to examples. These descriptions do not limit the present invention.
As the silica fine particles (1), Nissan Chemical Industries, Ltd., IPA-ST, average particle size 44 nm, colloidal silica, 30% solid content liquid was used.
As the silica fine particles (2), Nissan Chemical Industries, Ltd., IPA-ST (L), an average particle size of 12 nm, colloidal silica, and a solid content 30% solution were used.
As the silica fine particles (3), Nissan Chemical Industries, Ltd., IPA-STZL, average particle size of 80 nm, colloidal silica, 30% solid content liquid was used.
As silica particles (4), silica fine particles having an average particle diameter of 1000 nm were used.
As the polyfunctional monomer (B), Nippon Kayaku Co., Ltd., pentaerythritol triacrylate, product name PET30 was used.
As the polyfunctional monomer (B), Nippon Kayaku Co., Ltd., dipentaerythritol hexaacrylate, product name DPHA was used.
As the polyfunctional monomer (B), product name M215 (molecular weight 333, number of reactive functional groups 2) manufactured by Toagosei Co., Ltd. was used.
As a polyfunctional monomer (B), Nippon Kayaku Co., Ltd. product name DPCA120 (molecular weight 1947, number of reactive functional groups 6) was used.
As the polymer (C), Arakawa Chemical Industries, Ltd., product name BS371 (weight average molecular weight 40000, number of reactive functional groups 30 or more) was used.
As the polymer (C), Arakawa Chemical Industries, Ltd., product name BS371MLV (weight average molecular weight 20000, number of reactive functional groups 30 or more) was used.
As the polymer (C), Arakawa Chemical Industries, Ltd., product name BS371 modified (weight average molecular weight 80000, number of reactive functional groups 30 or more) was used.
As polymer (C), Negami Kogyo Co., Ltd. product name UN5507 (weight average molecular weight 17000, number of reactive functional groups less than 30) was used.
As a polymerization initiator, Irgacure 184 manufactured by Ciba Japan Co., Ltd. was used.
As a silane coupling agent, 3-methacryloxypropyltrimethoxysilane, KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd., was used.
As the transparent substrate film, a TAC film (thickness 40 μm, triacetylcellulose resin film, trade name: KC4UY, manufactured by Konica Corporation) was used.
Abbreviations for each compound are as follows.
PETA: pentaerythritol triacrylate DPHA: dipentaerythritol hexaacrylate MIBK: methyl isobutyl ketone IPA: isopropanol TAC: triacetyl cellulose

(Preparation of reactive silica fine particles (1))
The silica fine particles (1) were solvent-substituted from IPA to MIBK using a rotary evaporator to obtain a MIBK dispersion having 30% by weight of silica particles. By adding 5 parts by weight of 3-methacryloxypropylmethyldimethoxysilane to 100 parts by weight of this MIBK dispersion and subjecting it to a heat treatment at 50 ° C. for 1 hour, the solid content of the surface-treated reactive silica fine particles having an average particle diameter of 44 nm is obtained. A 30 wt% MIBK dispersion was obtained.

(Preparation of reactive silica fine particles (2))
In the preparation of the reactive silica fine particles (1), the solid content of the surface-treated reactive silica fine particles (2) having an average particle diameter of 12 nm was similarly obtained except that the silica fine particles (1) were replaced with the silica fine particles (2). A 30 wt% MIBK dispersion was obtained.

(Preparation of reactive silica fine particles (3))
In the preparation of the reactive silica fine particles (1), the solid content of the surface-treated reactive silica fine particles (3) having an average particle diameter of 80 nm was similarly obtained except that the silica fine particles (1) were replaced with the silica fine particles (3). A 30 wt% MIBK dispersion was obtained.

(Preparation of reactive silica fine particles (4))
In the preparation of the reactive silica fine particles (1), except that the silica fine particles (1) are replaced with the silica fine particles (4), the solid content of the surface-treated reactive silica fine particles (4) having an average particle diameter of 1000 nm is the same. A 30 wt% MIBK dispersion was obtained.

(Preparation of curable resin composition)
Components of the composition shown in Table 1 were blended to prepare curable resin compositions 1-1 to 1-10, 2-1 to 2-4, and 3-1 to 3-12, respectively.

Example 1: Production of a hard coat film The curable resin composition 1-1 was applied as a first curable resin composition to one side of a TAC film and dried in a hot oven at a temperature of 70 ° C for 60 seconds. The first hard coat layer (lower layer) having a thickness of 10 μm was formed by evaporating the solvent in the coating film and curing the coating film by irradiating ultraviolet rays so that the integrated light amount was 100 mJ / cm ² . . Furthermore, the said curable resin composition 2-1 was apply | coated as said 2nd curable resin composition on the said 1st hard-coat layer, and it dried for 60 second in a 70 degreeC hot oven, and a coating film The second hard coat layer (upper layer) having a thickness of 5 μm was formed by evaporating the solvent therein and irradiating ultraviolet rays with an integrated light amount of 200 mJ / cm ² to cure the coating film. 1 hard coat film was produced.
In addition, the 1st curable resin composition was apply | coated to the 40-micrometer-thick TAC film, the hard-coat layer was formed, and the result of having measured the Vickers hardness of 2 layer structure of a TAC film / first hard-coat layer is shown. It shows according to 2.
Similarly, the second curable resin composition was applied to a TAC film having a thickness of 40 μm, a hard coat layer was formed, and the results of measuring the Vickers hardness of the two-layer structure of the TAC film / second hard coat layer were obtained. It shows according to Table 2.
Table 2 also shows the absolute value of the difference in Vickers hardness between the first hard coat layer and the second hard coat layer.

  As the first and second curable resin compositions, the curable resin compositions are shown in Table 2, respectively, except that the film thicknesses of the first and second hard coat layers are changed as shown in Table 2. Produced the hard coat films of Examples 2 to 17 and Comparative Examples 1 to 34 in the same manner as in Example 1.

(Evaluation of hard coat film)
About the produced hard coat film of Examples 1-17 and Comparative Examples 1-34, pencil hardness, total light transmittance, haze, curl property, and crack property were evaluated as follows. The results are shown in Table 2.

(Evaluation: Pencil hardness)
Pencil hardness test: The hardness of the pencil scratch test is a test specified by JIS-S-6006 after conditioning the prepared hard coat film (the optical laminate) at a temperature of 25 ° C. and a relative humidity of 60% for 2 hours. The pencil hardness test (4.9N load) prescribed | regulated to JISK5600-5-4 (1999) was done using the pencil for ware, and the highest hardness which does not get a damage | wound was measured.

(Evaluation: Total light transmittance)
The total light transmittance (%) of the prepared hard coat film was measured according to JIS K-7361 using a haze meter (Murakami Color Research Laboratory, product number: HM-150).
○: 90% or more ×: less than 90%

(Evaluation: Haze)
The haze value (%) of the prepared hard coat film was measured according to JIS K-7136 using a haze meter (Murakami Color Research Laboratory, product number: HM-150).
○: 1.0% or less ×: larger than 1.0%

(Evaluation: Curl property)
The degree of curling of the hard coat film (curl width) is determined by placing a sample piece of the hard coat film cut to 10 cm × 10 cm with the TAC film down on a horizontal base (plane), and the end point of the hard coat layer that has been lifted The average value (mm) of the distance between them was evaluated.
Evaluation criteria Evaluation ○: 1 to 85 mm.
Evaluation x: Less than 1 mm, or a roll-like object.

(Evaluation: Crack property)
The hard coat film cut to a size of 10 × 2 cm was wound around a circular cylinder with the hard coat layer surface on the outside, and the curvature diameter at which cracking (crack) started to occur was measured.
Evaluation criteria Evaluation ○: Within 14 mm.
Evaluation x: It was 15 mm or more.

  From Table 2, in Examples 1 to 17, the Vickers hardness of the first and second hard coat layers is 53 to 69 Hv, respectively, and the absolute value of the difference is within 13, the pencil hardness and the total light transmittance. Excellent evaluation was obtained in haze, curling property, and cracking property.

However, in Comparative Example 1 in which the first curable resin composition 3-1 did not contain the polyfunctional monomer (B), the pencil hardness was as low as 3H.
In Comparative Example 2 in which the first curable resin composition 3-2 did not contain the polymer (C), the evaluation of curl and crack was poor.
In Comparative Example 3 in which the average particle size of the reactive silica fine particles (A) of the first curable resin composition 3-3 was large, the transmittance and haze were poorly evaluated.
In Comparative Example 4 in which the first curable resin composition 3-4 did not contain the reactive silica fine particles (A), the pencil hardness was as low as 3H.
In Comparative Example 5 in which the first curable resin composition 3-5 did not contain the reactive silica fine particles (A) and the polyfunctional monomer (B), the pencil hardness was as low as 2H.
In Comparative Example 6 in which the content of the reactive silica fine particles (A) contained in the first curable resin composition 3-6 was less than 30% by weight, the pencil hardness was as low as 3H.
In Comparative Example 7 in which the content of the reactive silica fine particles (A) contained in the first curable resin composition 3-7 exceeds 65% by weight, the pencil hardness was as low as 3H, and the evaluation of cracks was also poor.
In Comparative Example 8 in which M215 of the polyfunctional monomer (B) contained in the first curable resin composition 3-8 was bifunctional, the pencil hardness was as low as 2H.
In Comparative Example 9 in which the molecular weight of DPCA120 of the polyfunctional monomer (B) contained in the first curable resin composition 3-9 exceeds 1000, the pencil hardness was as low as 3H.
In Comparative Example 10 in which the number of functional groups of UN5507 of the polymer (C) contained in the first curable resin composition 3-10 was less than 30, the pencil hardness was as low as 3H.
In Comparative Example 11 in which the molecular weight of BS371 modification of the polymer (C) contained in the first curable resin composition 3-11 exceeds 50000, the pencil hardness was as low as 3H.
In Comparative Example 12 in which the silica fine particles contained in the first curable resin composition 3-12 did not have a reactive group, the pencil hardness was as low as 3H, and the evaluation of cracks was also poor.

  In Comparative Examples 13 to 16 using the first curable resin compositions 2-1 to 2-4, since the content of the reactive silica fine particles (A) is small, the pencil hardness is as low as 3H, and the curl is evaluated. It was bad.

  In Comparative Examples 17 to 26 in which the curable resin compositions 1-1 to 1-10 in which the content of the reactive silica fine particles (A) is 30% by weight or more are used as the second curable resin composition, the pencil hardness is It was as low as 3H.

In Comparative Example 27 in which the second curable resin composition 3-1 did not contain the polyfunctional monomer (B), the pencil hardness was as low as 3H.
In Comparative Example 28 in which the second curable resin composition 3-2 did not contain the polymer (C), the pencil hardness was as low as 3H.
In Comparative Example 29 in which the second curable resin composition 3-5 did not contain the reactive silica fine particles (A) and the polyfunctional monomer (B), the pencil hardness was as low as 3H.

The content of the reactive silica fine particles (A) contained in the first curable resin composition 3-7 exceeds 65% by weight, and the second curable resin composition 3-2 contains the polymer (C). In Comparative Example 30, which had no pencil, the pencil hardness was as low as 3H, and the evaluation of cracks was also poor.
In Comparative Example 31 in which only the first hard coat layer was not formed and the second hard coat layer was not formed, the pencil hardness was as low as 3H.
In Comparative Example 32 in which only the second hard coat layer was not formed and the first hard coat layer was not formed, the pencil hardness was as low as 2H.
In Comparative Example 33 where the thickness of the first hard coat layer was as thick as 25 μm, the evaluation of curl and cracks was poor.
In Comparative Example 34 where the film thickness of the second hard coat layer was as thick as 25 μm, the evaluation of curl and cracks was poor.

FIG. 1 is a cross-sectional view schematically showing an example of a layer configuration of a hard coat film according to the present invention. FIG. 2 a is a cross-sectional view schematically showing an example of a hard coat film that is not curled. FIG. 2 b is a perspective view schematically showing an example of a hard coat film in a state where it is not curled. FIG. 3 a is a cross-sectional view schematically showing an example of a curled hard coat film. FIG. 3 b is a perspective view schematically showing an example of a hard coat film in a state where it is not curled. FIG. 4 is a cross-sectional view schematically showing another example of a curled hard coat film. FIG. 5 is a cross-sectional view schematically showing another example of the layer configuration of the hard coat film according to the present invention. FIG. 6 is a cross-sectional view schematically showing another example of the layer configuration of the hard coat film according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hard coat film 2, 3, 4, 5 End point 6 Distance 10 between end points Transparent base film 20 First hard coat layer 30 Second hard coat layer 40 Center angle 50 Antistatic layer 60 Low refractive index layer

Claims (2)

A hard coat film in which a first hard coat layer and a second hard coat layer are provided adjacent to the first hard coat layer from the side close to the transparent base film on one side of the transparent base film. And
The first hard coat layer comprises reactive silica fine particles (A) having an average particle diameter of 10 to 100 nm having a reactive functional group a on the particle surface,
A polyfunctional monomer (B) having 3 or more reactive functional groups b in one molecule and a molecular weight of 1000 or less, and
The reactive silica fine particle comprising a cured product of a first curable resin composition containing a polymer (C) having 30 or more reactive functional groups c in the molecular side chain and a weight average molecular weight of 10,000 to 50,000. (A) is included in an amount of 30 to 65% by weight based on the total solid content of the first curable resin composition,
The second hard coat layer comprises reactive silica fine particles (D) having an average particle diameter of 10 to 100 nm having a reactive functional group d on the particle surface, and
It consists of a cured product of a second curable resin composition containing a polyfunctional monomer (E) having 3 or more reactive functional groups e in one molecule and a molecular weight of 1000 or less, and the reactive silica fine particles ( D) is 0 wt% or more and less than 30 wt% with respect to the total solid content of the second curable resin composition,
The reactive functional groups a, b, c, d and e have cross-linking reactivity between the same and different reactive functional groups, respectively, and
Each of the first hard coat layer and the second hard coat layer has a film thickness of 20 μm or less, a Vickers hardness of 53 to 69 Hv at an indentation load of 100 mN, and the first hard coat layer and the second hard coat layer. A hard coat film, wherein the absolute value of the difference in Vickers hardness of the coat layer is 13 or less.   A film obtained by cutting the hard coat film according to claim 1 into a size of 10 × 10 cm, wherein the hardness of a pencil hardness test (4.9 N load) specified in JIS K5600-5-4 (1999) is 4H or more. The average value of the distance between the end points of the sides constituting the floated curved surface placed on a flat surface with the transparent base film facing down is 1 to 85 mm. Hard coat film.

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