JP4834990B2 - Anti-glare laminate and display device - Google Patents

Description

  The present invention relates to an antiglare film for a display excellent in antiglare property and surface hardness and having high image contrast, and a display device using the same.

  Usually, the display surface is glass or plastic, but a hard coat treatment with a methacrylic resin is performed to prevent the screen from being damaged. Since the methacrylic resin exhibits a high surface altitude, the methacrylic resin exhibits good scratching properties, but also has a feature of high glossiness, which causes a new problem of glare on the display surface. In order to solve this problem, Patent Document 1 reports an antiglare treatment in which a cohesive silica gel is blended with a polyester acrylate resin.

  Thus, by blending inorganic particles such as silica gel particles, high antiglare properties can be obtained, but since there is a difference in the refractive index between the resin and the particles, Light scattering also occurs at the same time, resulting in whitening of the film, which may be accompanied by a reduction in display contrast. For such a problem, in Patent Document 2, the refractive index difference between the particles and the binder is set to 0.01 to 0.5, and scattering generated inside the hard coat layer is suppressed, and in particular, the internal haze is set to 1 to 15. Therefore, it has been reported that high visibility can be obtained.

  However, with the recent increase in resolution of display products, there is an increasing demand for anti-glare films with improved anti-glare properties and contrast. Even when an anti-glare film having an internal haze of more than 1 is used, sufficient contrast cannot be obtained, white blurring of the image, deterioration of visibility, and the like become a problem. There is an increasing demand for films showing contrast and high antiglare properties.

JP 59-151109 A Japanese Patent No. 3507719

  The object of the present invention is to solve the above-mentioned problems and to obtain an antiglare laminate having good antiglare properties and contrast with high reliability. In particular, an object of the present invention is to obtain an antiglare laminate capable of obtaining good antiglare properties and contrast when used in display devices with high resolution in recent years. Moreover, it aims at providing the display apparatus which used this anti-glare laminated body for the front.

In the invention according to claim 1, the antiglare hard coat layer (B) is laminated on the base material (A), and the antireflection layer (F) is laminated on the antiglare hard coat layer (B). The anti-glare hard coat layer (B) comprises a compound (C) having a (meth) acryloyl group in the molecule and fine particles (D) having a particle diameter of 1 μm to 10 μm (meta ) Compound (C) having 1 to 30 parts by weight per 100 parts by weight of compound (C) having acryloyl group in the molecule and having (meth) acryloyl group in the molecule has trialkoxysilyl group in the molecule a (meth) contains an acrylic compound (E), and said anti-reflective layer (F) is formed by a coating solution containing a hydrolyzate of silicon alkoxide,
Moreover, the refractive index difference between the refractive index of the entire antiglare hard coat layer (B) and the refractive index of the fine particles (D) is less than 0.01, the total haze is 5 to 15%, and the internal haze Is an antiglare laminate, characterized by being less than 0.4%.

The invention according to claim 2 is a display device characterized by using the antiglare laminate according to claim 1 on the front surface.

  ADVANTAGE OF THE INVENTION According to this invention, the anti-glare laminated body which shows favorable anti-glare property and contrast can be obtained with high reliability. Moreover, it can be set as the display apparatus which shows high anti-glare property and favorable contrast by using the anti-glare laminated body of this invention for the front surface of a display apparatus.

Hereinafter, embodiments of the present invention will be described in detail.
In the present invention, the substrate (A) is used on the display surface or inside thereof, and is not particularly limited, and a highly transparent film can be used. For example, polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefins such as polyethylene (PE) and polypropylene (PP), cycloolefins such as norbornene, and celluloses such as triacetyl cellulose (TAC) Examples thereof include polyether sulfones such as polyether sulfone (PES), but are not limited thereto. In particular, when a cellulose film such as TAC is used, a highly visible and highly reliable laminate can be obtained.

The compound (C) having a (meth) acryloyl group in the molecule contained in the antiglare coat layer (B) of the present invention is irradiated with an active energy ray, whereby the (meth) acryloyl group is polymerized to form a crosslinked structure. It becomes what is called a hard-coat component which can obtain high surface hardness by taking.
The compound (C) having a (meth) acryloyl group in the molecule is not particularly limited, but high surface hardness can be obtained when a compound having three or more (meth) acryloyl groups is used. Moreover, what has 1-2 (meth) acryl groups can also be used according to the objectives, such as adhesiveness and a softness | flexibility.

For example, as a compound having 3 or more (meth) acryloyl groups in the molecule, dipentaerythritol hexa (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, trimethylolpropane triacrylate, (Meth) acrylic polyfunctional monomers such as trimethylolpropane tetraacrylate, polyfunctional urethane acrylates, and polyfunctional epoxy acrylates can be used. In particular, when dipentaerythritol hexa (meth) acrylate and pentaerythritol tri (meth) acrylate are used, high surface hardness, scratch resistance, and quick curing can be obtained.
Examples of the compound having 1 to 2 (meth) acryloyl groups include compounds having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, Compounds having amino groups such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, (meth) acrylic acid, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl hexahydro Compounds having a carboxyl group such as phthalic acid, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, cyclohexyl (meth) acrylate, phenoxyethyl (meth) acrylate, isobornyl (meth) acrylate, etc. (Meth) acrylate having a skeleton, isoamyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, Acrylic monofunctional compounds such as methoxydipropylene glycol (meth) acrylate. And diethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, and triethylene di (meth) acrylate , PEG # 200 di (meth) acrylate, PEG # 400 di (meth) acrylate, PEG # 600 di (meth) acrylate, neopentyl di (meth) acrylate, dimethylol tricyclodecane di (meth) acrylate, etc. And bifunctional epoxy (meth) acrylate and bifunctional urethane acrylate.

  A compound having three or more (meth) acrylic groups and one or more (meth) acrylic compounds can be used in combination, and the compounding ratio at that time has three or more (meth) acrylic groups. It is preferable that it is 0-50 weight part of 1-2 (meth) acrylic compounds with respect to 50-100 weight part of compounds. If it exceeds 50 parts by weight, the crosslink density decreases, so that sufficient surface hardness may not be obtained.

The (meth) acrylic compound (E) having a trialkoxysilyl group in the molecule of the present invention has an antiglare hard coat when an antireflection layer (F) is provided on the antiglare hard coat layer (B). The adhesion between the layer (B) and the antireflection layer (F) is improved.
When the active energy ray is irradiated to the antiglare hard coat layer (B), the (meth) acryl group is incorporated into the crosslinked structure of the compound (C) having a (meth) acryloyl group in the molecule, The alkoxysilyl group is simultaneously hydrolyzed during the hydrolysis reaction of the antireflection layer, resulting in a chemical bond with the structure of the antireflection layer. Thereby, the coupling | bonding between a glare-proof layer (B) and an antireflection layer (F) shows high adhesiveness.
Normally, when laminating an inorganic antireflection layer on an antiglare hard coat layer, fine surface irregularities can be formed by treating the surface of the hard coat with a surface treatment such as corona, plasma, laser, or alkali. The adhesion is improved by forming and obtaining an anchor effect, but in the present invention, the surface treatment step of the hard coat layer can be omitted, and the cost is greatly reduced as compared with the conventional antireflection film. be able to.

The (meth) acrylic compound (E) having a trialkoxysilyl group in the molecule is not particularly limited, and γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ-acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropylmethyldiethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ- (meth) acryloxypropyl-tris (β-methoxyethoxy) silane, etc. Is mentioned.
The amount of the (meth) acrylic compound (E) having a trialkoxysilyl group is 1 to 50 parts by weight with respect to 50 to 99 parts by weight of the compound (C) having a (meth) acryloyl group in the molecule. If the amount is less than 1 part by weight, sufficient adhesion cannot be obtained, and if it exceeds 50 parts by weight, sufficient surface hardness cannot be obtained. Preferably it is 5-30 weight part, More preferably, it is 10-25 weight part, and high adhesiveness and surface hardness can be obtained at this time.

The fine particles (D) are so-called anti-glare agents that form anti-glare properties on the surface of the anti-glare hard coat layer (B) and exhibit anti-glare properties by scattering light reflected from the surface of the coat layer. 1-10 micrometers can be used for microparticles | fine-particles (D). Preferably, when 3 to 7 μm is used, high antiglare property and image contrast can be obtained.
As the fine particles (D), organic fine particles or inorganic fine particles can be used. In either case, there is no particular limitation.

  In the present invention, the fine particles (D) can be used such that the difference from the refractive index of the formed antiglare hard coat layer (B) is less than 0.01. Preferably, it is less than 0.005, and more preferably, when the difference is 0, high transparency and image contrast can be obtained. If it is this range, an internal haze can be suppressed and a favorable anti-glare property and contrast can be obtained even when used for a high-resolution display in recent years.

The total haze is preferably in the range of 3 to 30 (%). If it is this range, sufficient anti-glare property will be acquired. Preferably, it is 5 to 20 (%), more preferably 5 to 15 (%).
The internal haze is preferably less than 0.4 (%). Within this range, internal diffusion can be suppressed, and good anti-glare properties and contrast can be obtained even when used in high-resolution displays.

The organic fine particles are not particularly limited, and fine particles that are cross-linked polymers made of acrylic resin, styrene resin, benzoguanine resin, melamine resin, and formaldehyde resin can be used. Fine particles obtained by copolymerizing these resins can also be used. In particular, when fine particles made of an acrylic styrene copolymer resin are used, it is very easy to adjust the refractive index, and high transparency can be achieved.
The inorganic fine particles are not particularly limited, and silica, alumina, talc, glass filler and the like can be used. In particular, a glass filler having an adjusted refractive index is suitable.

  The fine particles (D) are preferably 1 to 30 parts by weight with respect to 100 parts by weight of the compound (D) having a (meth) acryloyl group in the molecule. When the amount is less than 1 part by weight, sufficient anti-glare property cannot be obtained, and when it exceeds 30 parts by weight, the scattering of the surface becomes strong and the image contrast is lowered. Preferably it is 3-20 weight part, More preferably, it is 5-10 weight part, At this time, high contrast can be shown.

  In the antiglare hard coat layer (B) in the present invention, it is preferable to add a photoinitiator. The photoinitiator is not particularly limited, and a compound (G) that generates radicals when irradiated with active energy such as ultraviolet rays can be used. For example, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-methyl [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2,2- Dimethoxy-1,2-diphenylethane-1-one, benzophenone, 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl 1-propan-1-one, 2-benzyl-2-dimethylamino-1 -(4-Morpholinophenyl) butan-1-one, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide and the like can be used.

In the present invention, the compounding amount of the compound (G) is 0.1 to 10 parts by weight, preferably 1 to 7 parts by weight, more preferably 100 parts by weight of the compound (D) having a (meth) acryloyl machine in the molecule. Is 1 to 5 parts by weight. When the amount is less than 0.1 part by weight, the hardness of the antiglare coat layer (B) is insufficient, and when it exceeds 10 parts by weight, the hard coat film may be easily cracked. In particular, when the compounding amount of the compound (G) is set to 1 to 5 parts by weight, the antiglare coat layer (B) is efficiently cured, and the generation of cracks can be prevented.
The antiglare hard coat layer (B) of the present invention is prepared by dissolving the compound (C), the fine particles (D) and the compound (G) in an appropriate solvent using an appropriate mixing apparatus such as a homomixer. be able to.

  The solvent is not particularly limited, but ketones such as methyl ethyl ketone, acetone, and methyl isobutyl ketone, esters such as methyl acetate, ethyl acetate, and butyl acetate, aromatic compounds such as toluene and xylene, diethyl ether, tetrahydrofuran, and the like Examples include ethers, alcohols such as methanol, ethanol, and isopropanol. The concentration is, for example, about 10 to 90% with respect to the solid content.

  The coating method on the base material of the antiglare hard coat layer (B) of the present invention can be applied by a conventional coating method such as slot coater, spin coater, roll coater, curtain coater, screen printing, etc. . The film thickness of the film formed at this time is usually about 0.1 to 50 μm, preferably 1 to 30 μm, and more preferably 5 to 20 μm. If it is less than 0.1 μm, sufficient pencil hardness cannot be obtained, and if it is thicker than 50 μm, cracks are likely to occur.

In the present invention, the antireflection layer (F) can be laminated on the antiglare hard coat layer (B).
A known antireflection layer (F) can be used. For example, a low refractive index layer having a refractive index of 1.2 to 1.5, a high refractive index layer having a refractive index of 1.8 to 2.5, and a low refractive index layer having a refractive index of 1.2 to 1.5 Or a high refractive index layer having a refractive index of 1.8 to 2.5, a medium refractive index layer having a refractive index of 1.5 to 1.9, and a low refractive index having a refractive index of 1.2 to 1.5. The thing which combined the rate layer alternately can be mentioned.

As the low refractive index layer single layer, for example, a hydrolyzate of magnesium fluoride, silicon oxide or silicon alkoxide can be used.
As the silicon alkoxide, a compound represented by the following general formula (1) can be used.
R _x Si (OR) _4-x
(In the formula, R represents an alkyl group, and x is an integer satisfying 0 ≦ x ≦ 4.)
As such, for example, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, isobutyltrimethoxysilane, dimethyldimethoxysilane And dimethyldiethoxysilane.

Further, the refractive index can be lowered by further using low refractive fine particles for the hydrolyzate of silicon alkoxide. Since the porous fine particles contain fine particle air (refractive index n = 1.0), the refractive index can be lowered.
The porous fine particles preferably have a refractive index n of 1.40 or less, inorganic fine particles such as silica, antimony pentoxide, tin oxide, zinc oxide, ITO (indium tin oxide), ATO (antimony tin oxide), Organic fine particles such as polypyrrole, polyaniline, polythiophene, and polyfluorene can be used. These fine particles can be used alone, in combination with two or more kinds of mixed fine particles, or in combination of two or more kinds of fine particles.

  As the middle refractive index layer and the high refractive index layer, for example, an oxide, nitride, or oxynitride mainly composed of titanium, tantalum, zirconium, zinc, indium, hafnium, cerium, tin, niobium, or aluminum is used. it can.

  As a method of forming the antireflection layer (F), it can be formed by a vapor phase method such as vapor deposition, sputtering, chemical vapor deposition, or various coating methods.

  Moreover, you may provide functional layers, such as a pollution prevention layer, in the anti-glare laminated body of this invention.

  The antiglare laminate of the present invention can be provided on the front surface of a display device such as a liquid crystal display device.

  As compound (C), 95 parts by weight of dipentaerythritol hexaacrylate (manufactured by Kyoei Co., Ltd., light acrylate DPE-6A) and as compound (F), 5 parts by weight of γ-acryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Silicone, KBM5103) 10 parts by weight of organic fine particles (refractive index 1.520) made of acrylic styrene resin having an average particle size of 5.5 μm as fine particles (D), and 1-hydroxycyclohexyl phenyl ketone (manufactured by Ciba Geigy, Irgacure 184) as compound (J) ) 5 parts by weight are mixed and dissolved in methyl ethyl ketone, coated on a TAC film to a thickness of 10 μm with a roll coater, cured by UV irradiation after removing the solvent in an oven, and antiglare with a refractive index of 1.520 A coat layer was obtained.

Subsequently, 190 parts by weight of 7 parts by weight of an oligomer obtained by hydrolyzing tetraethoxysilane with 1 mol / L hydrochloric acid and 3 parts by weight of silica particles having a refractive index of 1.20 as porous fine particles on the antiglare coat layer. The coating solution for the antireflection layer (F) diluted with part of isopropanol was applied so that the dry film thickness was 100 nm, and the antireflection layer (F) having a refractive index of 1.38 at a wavelength of 550 nm was formed, An antireflection film was obtained.
The obtained film was evaluated for pencil hardness, adhesion, scratch resistance, luminous reflectance, transmittance, haze, and image contrast.

<Pencil hardness>
This was performed in accordance with JIS K5400.
<Adhesion>
This was performed in accordance with JIS K5400.
<Abrasion resistance>
The steel wool (# 0000) was subjected to 10 reciprocal scratches with 250 g, and the presence or absence of scratches was visually confirmed.
<Visual reflectance>
Using an automatic spectrophotometer (U-4000, manufactured by Hitachi, Ltd.), the luminous reflectance was measured from the spectral reflectance. At the time of measurement, the surface opposite to the coated surface was matted and black paint was applied, and antireflection treatment from the back side was performed.
<Transmissivity>
It measured using the image clarity measuring device [Nippon Denshoku Industries Co., Ltd. make, NDH-2000].
<All Haze>
It measured using the image clarity measuring device [Nippon Denshoku Industries Co., Ltd. make, NDH-2000].
<Internal Haze>
After applying a triacetyl cellulose film to the coated surface of the antiglare laminate through an adhesive to eliminate the unevenness of the antiglare laminate, a photometric measuring device (manufactured by Nippon Denshoku Industries Co., Ltd., NDH-2000).
<Image contrast>
The contrast between the black image and the white image was visually evaluated.

  As compound (C), 50 parts by weight of pentaerythritol triacrylate (Nippon Kayaku Co., Ltd., Kayrad PET-30), 20 parts by weight of 1,4-hexanediol diacrylate (manufactured by Kyoeisha, Light Acrylate 1.6HX-A), Example 1 except that 30 parts by weight of γ-acryloxypropyltrimethoxysilane as compound (E) and 30 parts by weight of glass filler (refractive index 1.502) having an average particle size of 5.0 μm as fine particles (D) were used. And an antiglare layer having a refractive index of 1.500 was obtained.

<Comparative example 2>
The same procedure as in Example 1 was performed except that silica particles having an average particle diameter of 3.5 μm (Silicia 430, refractive index 1.46) were used as the fine particles (D).

  From Table 1, the sample of an Example has low internal diffusion, can obtain sufficient anti-glare properties, and can have high contrast when used in a display. The sample of the comparative example has good anti-glare properties, but has high internal diffusion and low contrast when used in a display.

Claims (2)

An antiglare laminate in which an antiglare hard coat layer (B) is laminated on a substrate (A), and an antireflection layer (F) is laminated on the antiglare hard coat layer (B). Yes, the antiglare hard coat layer (B) has a compound (C) having a (meth) acryloyl group in the molecule and fine particles (D) having a particle diameter of 1 μm to 10 μm in the molecule. 1 to 30 parts by weight per 100 parts by weight of compound (C),
The compound (C) having the (meth) acryloyl group in the molecule includes a (meth) acryl compound (E) having a trialkoxysilyl group in the molecule,
And the antireflection layer (F) is formed of a coating liquid containing a hydrolyzate of silicon alkoxide,
Moreover, the refractive index difference between the refractive index of the entire antiglare hard coat layer (B) and the refractive index of the fine particles (D) is less than 0.01, the total haze is 5 to 15%, and the internal haze Is less than 0.4%, an antiglare laminate. A display device comprising the antiglare laminate according to claim 1 on a front surface.