KR101779624B1 - Antireflection film, polarizing plate and image display device - Google Patents

Abstract

The present invention relates to an antireflection film having anti-saponification property and capable of maintaining functions such as antireflection property, antiscratching property and antifouling property by preventing the function of the low refractive index layer from being impaired even by saponification treatment, a polarizing plate using the same, Device.
The antireflection film (10) of the present invention is an antireflection film (2) which is composed of an ionizing radiation curable resin containing hollow silica particles formed on a transparent base film (1) of triacetyl cellulose, A multifunctional polymerizable compound having no hydroxyl group in the molecule or a polymerizable compound having a hydroxyl group in the molecule (as a whole) in the polymerizable compound of the resin is obtained by dividing the number of hydroxyl groups in one molecule by the molecular weight A compound having a functional group number of 3 to 9 and a molecular weight of 300 to 1000 is used as the multifunctional polymerizable compound having a hydroxyl group content of 100 or less. A functional layer such as a hard coat layer 3 may be provided under the low refractive index layer 2.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an antireflection film, a polarizing plate,

The present invention relates to an antireflection film, a polarizing plate and an image display device. In particular, the present invention relates to an antireflection film having an anti-saponification property capable of preventing performance deterioration during saponification treatment with an aqueous alkali solution, a polarizing plate using the same, and an image display device.

In an image display apparatus such as a liquid crystal display, a plasma display, an electroluminescence display, a touch panel, an electronic paper, and a tablet PC, an optical film for preventing flaws, contamination, As shown in Fig. For example, as an antireflection film, there is known an optical film in which a low refractive index layer is formed by applying a resin composition obtained by adding hollow silica particles as a low refractive index agent to an ionizing radiation curable resin on a transparent base film Open Publication No. 2010-85983 (Patent Document 1)).

By using an ionizing radiation curable resin in the resin of the low refractive index layer, antireflection and antifouling properties can be imparted to the antireflection film in addition to antireflection performance. Further, when the hard coat layer is formed between the low refractive index layer and the transparent base film, the scratch resistance can be further enhanced (see Patent Document 1).

In a liquid crystal display, a polarizing plate is usually formed on a liquid crystal cell. The polarizing plate is constituted by laminating both sides of a polarizer made of a polyvinyl alcohol film, in which iodine is adsorbed and oriented, with a protective film. In addition, a triacetyl cellulose film is usually used in view of transparency, optical orientation and the like. The surface of the protective film is saponified with an aqueous alkaline solution in order to improve adhesion with the polarizer, and then laminated with a polarizer.

However, in the image display apparatus, thinning is an important factor in performance, and it is desired to respond to the thinning of optical films. Therefore, instead of forming an antireflection film in addition to the polarizing plate, an antireflection film is laminated on the protective film of the polarizing plate by using an antireflection film, and a polarizing plate in which the antireflection film and the polarizing plate are integrated is thinned . Further, the protective film laminated on the polarizer is required to be subjected to a saponification treatment with an aqueous alkaline solution as an adhesion facilitating treatment in terms of adhesion with a polarizer.

However, when the antireflection film having a low refractive index layer is subjected to saponification treatment, the low refractive index agent in the low refractive index layer may fall off, or the resin constituting the low refractive index layer may be dissolved or omitted, and scratch resistance and antifouling property may be impaired.

In order to have the saponification property, the saponification protective film is temporarily adhered onto the low refractive index layer, but there is a problem of an increase in cost.

Accordingly, it is an object of the present invention to provide an anti-saponification protective film which can prevent the function of the low refractive index layer from being deteriorated even if a saponification treatment is carried out with an aqueous alkali solution without attaching the saponification protective film to maintain the functions of antireflection property, scratch resistance and antifouling property And to provide an anti-reflection film having anti-saponification property.

Another object of the present invention is to provide a polarizing plate and an image display device using such an antireflection film. In addition, maintaining the scratch resistance function in the present invention means not only maintaining the surface hardness of the low refractive index layer but also maintaining good interfacial adhesion between the low refractive index layer and its underlying layer.

The present invention provides an antireflection film, a polarizing plate and an image display device having the following constitutions.

(1) A transparent substrate film comprising triacetylcellulose, a transparent base material film formed on one side of the transparent base film and comprising a cured layer of an ionizing radiation curable resin and containing hollow silica particles and having a lower refractive index An antireflection film comprising a low refractive index layer,

The polymerizable compound contained in the ionizing radiation curable resin

(A) a multifunctional polymerizable compound having no hydroxyl group in the molecule,

(B) a polymerizable compound having a hydroxyl group in the molecule, a multifunctional polymerizable compound having a hydroxyl group content defined as a value obtained by dividing the number of hydroxyl groups contained in one molecule by the molecular weight by 100,

(C) When the resin composition contains a plurality of kinds of polymerizable compounds having a hydroxyl group in the molecule, the resin composition containing the plural kinds of polymerizable compounds at an arbitrary mass ratio may be used. When the polymerizable compound is regarded as one molecule and the weight average molecular weight of the whole polymerizable compound is used as the molecular weight of the single polymer, the ratio of the hydroxyl group content of the multifunctional polymerizable compound

Lt; / RTI >

Wherein the number of functional groups of the polyfunctional polymerizable compound in (A), (B) and (C) is from 3 to 9 and the molecular weight is from 300 to 1000.

(2) The antireflection film as described in (1) above, further comprising a functional layer formed between the transparent base film and the low refractive index layer.

(3) A polarizer comprising the antireflection film described in (1) or (2) above and a polarizer laminated on the surface of the antireflection film on the side of the transparent base film.

(4) An image display device comprising the antireflection film described in (1) or (2) or the polarizing plate described in (3) above.

(1) According to the antireflection film of the present invention, the anti-reflection property, the anti-scratch property (surface hardness and adhesion between the low refractive index layer and the lower layer thereof), the antiseptic property and the whitening resistance are not impaired in the saponification treatment It has Mars.

(2) The polarizing plate according to the present invention has anti-reflection properties, scratch resistance (surface hardness, adhesion between the low refractive index layer and its lower layer), antifouling property and whitening resistance by the antireflection film.

(3) According to the image display apparatus of the present invention, the image display surface can be provided with antireflective property, scratch resistance (surface hardness, adhesion between the low refractive index layer and the lower layer thereof), antifouling property and whitening resistance.

1 is a cross-sectional view for explaining an embodiment of an antireflection film according to the present invention.
2 is a cross-sectional view illustrating one embodiment of a polarizing plate according to the present invention.

Hereinafter, embodiments of the present invention will be described.

A. Antireflection Film

An antireflection film according to the present invention is a film comprising a transparent base film made of triacetyl cellulose and an antireflection film formed on one side of the transparent base film and composed of a cured layer of an ionizing radiation curable resin, And a low refractive index layer having a refractive index lower than that of the transparent base film. In addition, in the present invention, the ionizing radiation curable resin is composed of a resin composition containing a multifunctional polymerizable compound having a hydroxyl group in a molecule of less than a predetermined amount.

Further, the antireflection film of the present invention is preferable in that a hard coat layer is formed between the low refractive index layer and the transparent base film in order to further enhance scratch resistance. Here, FIG. 1 is a sectional view showing an example of an anti-reflection film according to the present invention. The antireflection film 10 in the same drawing is an optical film in the form in which the low refractive index layer 2 is formed on one side of the transparent base film 1 with the hard coat layer 3 interposed therebetween. The hard coat layer 3 is composed of a cured layer of an ionizing radiation curable resin.

Hereinafter, each layer will be described.

(Meth) acryloyl group means acryloyl group or methacryloyl group, (meth) acrylate means acrylate or methacrylate, and when it is simply acrylate, methacrylate group .

[Transparent substrate film]

The transparent base film (1) is a transparent film made of triacetylcellulose. By using a triacetylcellulose film (TAC film) for a transparent base film, excellent transparency and excellent optical isotropy suitable as a protective film of a polarizing plate for liquid crystal displays can be obtained. Thus, by using the TAC film, it is possible to obtain favorable optical characteristics when used with a polarizing plate in a liquid crystal display or when used as a protective film of a polarizing plate.

The transparency of the transparent base film is preferably at least 70%, preferably at least 85%, more preferably at least 90% of the average light transmittance in the visible light region of 380 to 780 nm. The refractive index of the transparent base film is about 1.49 in the case of the triacetylcellulose film.

The thickness of the transparent base film is usually 20 m to 300 m, preferably 30 m to 200 m.

As the triacetyl cellulose constituting the transparent base film (1), a resin other than acetic acid may be used as a fatty acid which forms an ester with cellulose such as cellulose acetate propionate and cellulose acetate butyrate in addition to pure triacetyl cellulose . The transparent base film may contain cellulose lower fatty acid ester resin other than triacetyl cellulose, such as diacetyl cellulose, if necessary.

The transparent base film (1) may contain various additives such as a plasticizer, an antistatic agent, and an ultraviolet absorber. The transparent base film 1 may be subjected to surface treatment for adhesion enhancement such as glow discharge treatment, corona discharge treatment, ultraviolet (UV) treatment, flame treatment, primer layer formation or the like, if necessary.

[Low refractive index layer]

The low refractive index layer 2 is made of a cured layer of a resin containing a low refractive index agent and has a refractive index lower than that directly below the low refractive index layer. The refractive index of the low refractive index layer is less than the refractive index of the immediately lower layer. However, the refractive index difference between the low refractive index layer and the immediate lower layer is preferably 0.02 to 0.3, more preferably 0.05 to 0.2.

The refractive index of the low refractive index layer is preferably 1.45 or less from the viewpoint of obtaining sufficient antireflection property, more preferably 1.40 or less, further preferably 1.38 or less.

The low refractive index layer (2) is composed of a cured layer of an ionizing radiation curable resin, and contains hollow silica particles as a low refractive index agent. Further, the ionizing radiation curable resin has a polyfunctional And a cured product of a resin composition containing a polymerizable compound. The ionizing radiation curable resin becomes a binder resin for the hollow silica particles and improves the scratch resistance of the low refractive index layer. The present radiation-curable resin is obtained by using a polymerizable compound having a hydroxyl group of less than a predetermined amount in a molecule to obtain saponification resistance, while using an ionizing radiation curable resin in the low refractive index layer, Refractive index layer is strengthened, scratch resistance is obtained. The hollow silica particles are, for example, fine particles having an outer shell and being porous or hollow in the inside thereof, as disclosed in Japanese Patent Application Laid-Open No. 6-330606, Japanese Patent Application Laid-Open No. 7-013137 , JP-A 7-133105, JP-A 2001-233611, and the like.

The thickness of the low refractive index layer is 50 to 150 nm, preferably 80 to 120 nm.

[Ionizing radiation curable resin]

The ionizing radiation curable resin is a resin which is cured by ionizing radiation typified by ultraviolet rays and electron beams and is one or two kinds of polymerizable compounds such as a monomer having a polymerizable functional group capable of being polymerized by ionizing radiation and a prepolymer Or more. Representative examples of the polymerizable functional group capable of polymerization by ionizing radiation include polymerizable unsaturated groups, and the polymerizable unsaturated group includes, for example, a group having a radically polymerizable ethylenic double bond such as a (meth) acryloyl group, a vinyl group, to be. Among them, (meth) acryloyl groups can be preferably used in the present invention, and various acrylate ionizing radiation curable resins are known.

The polymerizable compound is preferably a bifunctional or higher polyfunctional polymerizable compound in terms of scratch resistance (surface hardness, interface adhesion), more preferably a multifunctional polymerizable compound having three or more functions and a functionality of nine or less .

Of the multifunctional polymerizable compounds, those having no hydroxyl group in the molecule have saponification resistance and those having a hydroxyl group in the molecule can not obtain saponification resistance. The reason for this is presumably because the hydroxyl group has good affinity with the aqueous alkaline solution and destroys the crosslinked structure by attacking the alkali aqueous solution in the hydroxyl group in the three-dimensional crosslinked structure formed after curing by ionizing radiation. Further, it is presumed that the sodium hydroxide used in the saponification solution is easily infiltrated into the crosslinked structure because the sodium ion dissociated in the aqueous solution is very small.

Here, a specific example of the multifunctional polymerizable compound having no hydroxyl group in the molecule and a specific example of the multifunctional polymerizable compound having a hydroxyl group in which the internal saponification property can not be obtained, in which good saponification property can be obtained, For example.

Specific examples of the multifunctional polymerizable compound having no hydroxyl group in the molecule and having good internal saponification properties include trimethylolpropane triacrylate having three acryloyl groups as a polymerizable functional group represented by the following formula (TMPTA). In the formula (1), Ac is an acryloyl group.

However, in the case of trimethylolpropane triacrylate (TMPTA) represented by the general formula (1), three acryloyl groups as polymerizable functional groups are present, but the terminal methyl group is substituted with a hydroxyl group, (PETA) represented by the following formula (2) is not able to obtain saponification resistance. In the formula (2), Ac is an acryloyl group. This is a specific example of a multifunctional polymerizable compound having in its molecule a hydroxyl group in which no saponification property can be obtained.

As an example of a multifunctional monomer of an acrylate-based ionizing radiation curable resin, as an example of a multifunctional polymerizable compound having no hydroxyl group in the molecule to obtain good anti-saponification property, the bifunctional polymerizable compound includes hexanediol Acrylate, diethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate and the like .

Examples of the trifunctional polymerizable compound include trimethylolpropane tri (meth) acrylate (abbreviated as TMPTA), isocyanuric acid-modified tri (meth) acrylate, and the like, and the tetrafunctional polymerizable compound (Meth) acrylate and ditrimethylolpropane tetraacrylate. Examples of the hexafunctional polymerizable compound include dipentaerythritol hexa (meth) acrylate (abbreviated as DPHA) , And V802 (a polymer of DPHA, manufactured by Osaka Kikinagaku Kogyo Co., Ltd.) as the polymerizable compound having seven or more functionalities.

Examples of the multifunctional prepolymer of an acrylate-based ionizing radiation-curable resin include polyesters, polyethers, urethanes, epoxies, and silicones, which are examples of polyfunctional polymerizable compounds having no hydroxyl group in the molecule And various acrylate prepolymers.

Examples of polyfunctional polymerizable compounds having no hydroxyl group in the molecule include NK esters (dipentaerythritol hexaacrylate, pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, Shinnakamura) Manufactured by Kagaku Kogyo Co., Ltd.).

Among the examples of the multifunctional polymerizable compound having no hydroxyl group in the molecule, trimethylolpropane tri (meth) acrylate is preferably used as the compound that can be preferably used in the present invention. This compound exhibits particularly excellent scratch resistance for the saponification treatment.

(Use of a polymerizable compound having a hydroxyl group in its molecule)

As the resin composition of the ionizing radiation curable resin used for forming the low refractive index layer 2, it is most preferable that the polymerizable compound is composed of only the polyfunctional polymerizable compound having no hydroxyl group in the molecule . However, if it is within such a range as not to impair the saponification property, a polymerizable compound having a hydroxyl group in its molecule can be used for adjusting physical properties such as scratch resistance and application suitability. In this case, from the viewpoint of scratch resistance, a multifunctional polymerizable compound is preferable as the polymerizable compound having a hydroxyl group in the molecule.

Examples of polyfunctional polymerizable compounds having a hydroxyl group in the molecule include polyfunctional monomers of an acrylate-based ionizing radiation curable resin. Examples of polyfunctional monomers having one hydroxyl group in the molecule include trimethylolpropane Acrylate (abbreviated as TMPDA), pentaerythritol tri (meth) acrylate (abbreviated as PETA) and dipentaerythritol penta (meth) acrylate (abbreviated as DPPA) Examples of the polyfunctional monomer having a carboxyl group include dipentaerythritol tetra (meth) acrylate (abbreviated as DPTA).

In the case of the multifunctional polymerizable compound having a hydroxyl group in the molecule, a large proportion of the hydroxyl group in the molecule is not preferable from the viewpoint of the saponification resistance. It is preferable that the proportion of the hydroxyl group in the total amount of the resin composition of the ionizing radiation curing resin forming the low refractive index layer is as small as possible because the saponification resistance can be more surely improved.

(Hydroxyl group content)

Therefore, in the present invention, in the case of the multifunctional polymerizable compound having a hydroxyl group in the molecule, the number of hydroxyl groups (OH groups) contained in one molecule is divided by the molecular weight as an index of the proportion of the hydroxyl groups in the molecule The value obtained by multiplying 100 is defined as " hydroxyl group content ". As a specific example of the hydroxyl group content, the pentaerythritol tri (meth) acrylate (abbreviated as PETA) has an OH group number of 1 and a molecular weight of 298. Therefore, the hydroxyl group content of pentaerythritol tri (meth) 0.33, and the dipentaerythritol pentaacrylate (abbreviated as DPPA) has an OH number of 1 and a molecular weight of about 550, so that the hydroxyl group content of dipentaerythritol pentaacrylate is 0.18. In general, compounds such as TMPTA, PETA, DPHA, and DPPA are not completely OH-group compounds, but precisely occur during compound synthesis, so that the OH groups that can not be removed 100% However, in the case of calculating the hydroxyl group content in the present invention, the number of OH groups in the structural formula is calculated without taking into consideration a little.

The hydroxyl group content is preferably 0.2 or less. As the polyfunctional polymerizable compound, a compound having a hydroxyl group content of 0.2 or less in the number of hydroxyl groups contained in one molecule is used, whereby the desired anti-saponification property is obtained.

When the resin composition of the ionizing radiation curable resin is a mixture of plural kinds of polymerizable compounds, the content of the hydroxyl group is preferably 0.2 or less . When the molecular weight of the polymerizable compound is not a single but a molecular weight distribution, the weight average molecular weight is used for the molecular weight in the above formula. That is, in the case where the resin composition of the ionizing radiation curable resin includes a plurality of kinds of polymerizable compounds, including the case of having a molecular weight distribution, all of the polymerizable compounds contained in the resin composition are regarded as one molecule, The weight average molecular weight of all the above polymerizable compounds is used as the molecular weight of one molecule and the hydroxyl group content of the resin composition is calculated from the hydroxyl number of the molecules. The same applies to the case where a polymerizable compound having a hydroxyl group in the molecule and a polymerizable compound having no hydroxyl group in the molecule are included. For example, in the case of a resin composition containing a polymerizable compound having a molecular weight of 500 and a polymerizable compound having a molecular weight of 1000 in a mass ratio of 50:50 and having one hydroxyl group at one compound and no compound at the other , And the hydroxyl group content is calculated as (1/750) x 100 = 0.13, assuming that one hydroxyl group is present in the compound having the molecular weight of 750.

The number of functional groups of the multifunctional polymerizable compound in the case where the resin composition of such an ionizing radiation curable resin contains plural kinds of polymerizable compounds can be calculated in the same manner as the above-mentioned hydroxyl group content.

Examples of the compound capable of obtaining the desired saponification resistance even when the multifunctional polymerizable compound having a hydroxyl group in the molecule has a hydroxyl group content of 0.2 or less include dipentaerythritol pentaacrylate (DPPA) and dipentaerythritol penta Methacrylate (DPPMA) is preferably used in the present invention.

As the resin composition of the ionizing radiation curable resin for forming the cured layer of the ionizing radiation curable resin constituting the low refractive index layer (2), as the polymerizable compound, as the polymerizable compound having no hydroxyl group in the molecule, A multifunctional polymerizable compound is preferable, but a monofunctional polymerizable compound may be used in combination for physical property adjustment and the like.

Examples of the monofunctional monomer of an acrylate-based ionizing radiation curable resin include, for example, methyl (meth) acrylate, ethyl (meth) acrylate And other ethylenic polymerizable compounds such as methylhexyl (meth) acrylate, ethylhexyl (meth) acrylate, and the like.

(Molecular Weight)

The molecular weight of the multifunctional polymerizable compound having no hydroxyl group and the multifunctional polymerizable compound having a hydroxyl group is preferably two or more, more preferably three or more, and is preferably 300 or more in molecular weight. If the molecular weight is too large, however, under the thin film condition of 50 to 150 nm, the cross-linkable portion per one molecule in the whole layer in the layer decreases and the crosslinking density is lowered. As a result, the scratch resistance is lowered. Or less. Therefore, it is preferable that the molecular weight of the multifunctional polymerizable compound having no hydroxyl group and the multifunctional polymerizable compound having hydroxyl group is in the range of 300 to 1000. In the case of a polymerizable compound having a molecular weight distribution, this molecular weight means the weight average molecular weight.

The weight average molecular weight can be determined by polystyrene conversion by gel permeation chromatography (GPC). As the solvent for the GPC moving phase, tetrahydrofuran or chloroform may be used. For the measurement column, a commercially available column of tetrahydrofuran or chloroform column may be used in combination. Examples of commercially available columns include Shodex (registered trademark) GPC KF-801 and GPC KF-800D (both manufactured by Showa Denko K.K.). RI (differential refractive index) detector and UV detector may be used for the detector. The weight average molecular weight can be suitably measured by a GPC system such as Shodex (registered trademark) GPC-101 (manufactured by Showa Denko K.K.) using such a solvent, a column and a detector.

(Combined use of ionizing radiation specific gravity resin)

The ionizing radiation curable resin may contain, in addition to the ionizing radiation-curable polymerizable compound, an ionizing radiation specific gravity synthetic resin which is not polymerized by ionizing radiation, Maybe. The ionizing radiation non-polymerizable resin other than the ionizing radiation-curable polymerizable compound may be a polymerizable compound that can be cured by energy other than ionizing radiation, for example, a thermosetting resin that does not cure by ionizing radiation but is heat curable, Or a thermoplastic resin that does not harden.

Examples of the thermosetting resin include a urethane resin, a melamine resin, a phenol resin, and a silicone resin. Examples of the thermoplastic resin include an acrylic resin, a thermoplastic urethane resin, a polyamide resin, a styrene resin, a cellulose resin, a polycarbonate resin, a vinyl resin, and a silicone resin. Examples of the cellulose-based resin include nitrocellulose, acetylcellulose, cellulose acetate propionate, ethylhydroxyethylcellulose and the like.

(Polymerization initiator)

When the ionizing radiation curable resin is cured by ultraviolet rays, it is preferable to further contain a polymerization initiator in the resin composition of the ionizing radiation curable resin. As the polymerization initiator, known polymerization initiators such as acetophenone, benzophenone and thioxanone polymerization initiators are used when curing is carried out by radical polymerization. The polymerization initiator is used alone or in combination. In the case of commercially available products, for example, 1-hydroxycyclohexyl phenyl ketone is commercially available from Irgacure (registered trademark) 184 (BASF Japan Co., Ltd.), Irgacure 127 (BASF Japan Co., Manufactured by Mitsui Chemicals, Inc.). When curing is carried out by cationic polymerization, a polymerization initiator such as a metallocene system, an aromatic sulfonium system or an aromatic iodonium system is used. The polymerization initiator is added in an amount of 0.1 to 10 parts by mass based on 100 parts by mass of the resin.

(solvent)

The resin composition of the ionizing radiation curable resin may contain a solvent for adjusting physical properties such as coating application suitability on the transparent base film. Examples of the solvent include alcohols such as isopropyl alcohol, methanol, ethanol, butanol and isobutyl alcohol, ketones such as methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK) and cyclohexanone, propylene glycol mono (PGMEA); esters such as methyl acetate, ethyl acetate, butyl acetate and propyl acetate; halogenated hydrocarbons such as chloroform, methylene chloride and tetrachloroethane; and aromatic hydrocarbons such as toluene and xylene . Solvents may be used alone or as a mixture thereof. Among them, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA) and the like are preferable from the viewpoint of coating application suitability and dispersion stability to be.

(Antifouling agent)

It is preferable that the low refractive index layer 2 has antifouling property against contamination in that it becomes the outermost layer of the antireflection film. In this respect, it is preferable to include an antifouling agent in the low refractive index layer. As the antifouling agent, known antifouling agents can be suitably employed. Examples of the antifouling agent include a silicon-based compound and a fluorine-based compound. In addition, the antifouling agent is preferably an acrylate-based compound for the purpose of persistence of saponification resistance and curability. For example, a silicon acrylate compound, a fluorine-containing acrylate compound, an acrylate compound containing fluorine and silicon, and the like.

(Other additives)

Various known additives may be added to the resin composition of the ionizing radiation curable resin for property adjustment such as coating application suitability and dispersion stability of the low refractive index agent. For example, a leveling agent, a dispersion stabilizer, an antistatic agent, an ultraviolet absorber, an antioxidant, a refractive index adjusting agent, and the like.

[Hollow silica particles]

The hollow silica particles are particles having a function of lowering the refractive index while maintaining the film strength of the low refractive index layer. The hollow silica particles used in the present invention are fine silica particles having a structure having a cavity therein. The hollow silica particles are silica fine particles whose refractive index is lowered in inverse proportion to the occupancy of the internal cavity, as compared with the original refractive index (refractive index n = 1.46 or so) of the silica fine particles. As a result, the refractive index of the hollow silica particles as a whole particle is 1.20 to 1.45.

The hollow silica particles are not particularly limited as long as they are silica fine particles having cavities therein. For example, the hollow silica particles are fine particles having an outer shell and porous or hollow inside thereof, and are disclosed in Japanese Patent Application Laid-Open No. 6-330606, There may be mentioned silica fine particles prepared by using the technique disclosed in JP-A-7-013137, JP-A-7-133105, and JP-A-2001-233611.

The average particle diameter of the hollow silica particles is preferably 5 to 300 nm, more preferably 5 to 200 nm. When the average particle diameter is within this range, the low refractive index layer can impart excellent transparency. The range of the average particle diameter is more preferably 8 nm, more preferably 100 nm, still more preferably 10 nm, still more preferably 80 nm.

The content of the hollow silica particles in the low refractive index layer is not particularly limited, but is preferably in the range of 20 to 180 parts by mass based on 100 parts by mass of the resin solid content. If it exceeds 180 parts by mass, the film strength of the low refractive index layer may be insufficient. If it is less than 20 parts by mass, the effect of lowering the refractive index by the hollow silica particles can not be sufficiently imparted to the low refractive index layer.

Further, the surface of the hollow silica particles may be previously treated with a silane coupling agent before compounding. The silane coupling agent may be a commercially available product, and examples thereof include KBM-1003, KBE-1003, KBM-303, KBM-402, KBM-403, KBE-402, KBE-403 manufactured by Shinetsu Chemical Industry Co., , KBM-1403, KBM-502, KBM-503, KBE-502, KBE-503, KBM-5103, KBM-602, KBM-603, KBM-903, KBE- KBM-502, KBM-503, and KBM-502, which are silane coupling agents containing a (meth) acryloyl group, KBE-502, KBE-503, KBM-5103, and most preferably KBM-503.

[Formation of low refractive index layer]

The low refractive index layer 2 can be formed by applying the resin composition of the above ionizing radiation curable resin as a coating or an ink on a transparent base film and irradiating it with ionizing radiation to cure the resin. The coating method is not particularly limited and a well-known coating method may be suitably employed. Examples of the coating method include a roll coating method, a gravure coating method, a dipping method, a spraying method, a double coating method, a bar coating method, a spin coating method, and a meniscus coating method. Or by a printing method such as a flexo printing method or a screen printing method. As ionizing radiation, ultraviolet rays and electron beams are representative.

[Functional layer]

Other functional layers 3 can be formed between the transparent substrate film 1 and the low refractive index layer 2 as needed within the scope of the present invention without departing from the spirit of the present invention . For example, it is a transparent layer known as an optical film such as a hard coat layer, an antiglare layer, an antistatic layer, a high refractive index layer, and a primer layer. By forming the functional layer 3, functions according to the functional layer 3 formed can be added. For example, the functional layer 3 has an antiscrasing function in a hard coat layer, an antiglare function in an antiglare layer, an antistatic function in an antistatic layer, an antireflection function in a high refractive layer, Function can be given. Of these, the hard coat layer will be described below.

[Hard coat layer]

The term " hard coat layer " in this specification means a hardness of not less than " H " in a pencil hardness test (load of 500 g) prescribed by JIS K5600-5-4 (1999). It is preferable to form the hard coat layer 3 as a layer just below the low refractive index layer 2 between the low refractive index layer 2 and the transparent base film 1 to further enhance the scratch resistance of the antireflection film 10 .

The hard coat layer is formed as a cured layer of an ionizing radiation curable resin using a curable resin, more preferably an ionizing radiation curable resin. The thickness of the hard coat layer is 0.1 to 100 mu m, preferably 0.8 to 20 mu m.

As the ionizing radiation curable resin of the hard coat layer 3, various polymerizable compounds known as ionizing radiation curable resins can be used. For example, an ionizing radiation curable resin that has been heated in the above-described low refractive index layer can be preferably used. Therefore, similarly to the low refractive index layer, the ionizing radiation curable resin used in the hard coat layer is preferably formed of a resin composition containing a polymerizable compound having a hydroxyl group in a molecule smaller than a predetermined amount. Preferably, all the polymerizable compounds in the resin composition are polymerizable compounds having no hydroxyl group in the molecule. The polymerizable compound is preferably a polymerizable compound having at least two or more functional groups, more preferably three or more functional groups capable of being cured by ionizing radiation, from the viewpoint of improving scratch resistance.

Of the multifunctional polymerizable compounds, those having no hydroxyl group in the molecule have saponification resistance. If the compound has a hydroxyl group in the molecule, even if it is a preferable form in the low refractive index layer, the saponification temperature is high, , The abrasion resistance may be weakened under severe conditions. This is for the same reason as discussed in the column of the low refractive index layer.

The multifunctional polymerizable compound used in the low refractive index layer 2 preferably has a molecular weight of 300 to 1000 in terms of scratch resistance. However, in the multifunctional polymerizable compound used for the hard coat layer 3, the molecular weight May be a polymerizable compound exceeding 1,000.

However, since the hard coat layer 3 is not the outermost layer like the low refractive index layer, it is not in direct contact with the alkali aqueous solution during the saponification treatment. Therefore, the ionizing radiation curable resin of the hard coat layer is preferably a polymerizable Refractive index layer is not as strict as that of the compound. In this respect, as the ionizing radiation curable resin used for the hard coat layer, a polymerizable compound having a hydroxyl group in the molecule in the molecule may be more abundant than the ionizing radiation curable resin used for the low refractive index layer. However, since the low refractive index layer is as thin as 50 to 150 nm, it is preferable to use a polymerizable compound which does not have a hydroxyl group in the molecule as far as possible in consideration of penetration of an aqueous alkali solution.

In the case of using a polymerizable compound having a hydroxyl group in the molecule in the hard coat layer, preferred examples of the hard coat layer include pentaerythritol tri (meth) acrylate (abbreviated as PETA, hydroxyl group content: 0.33) Dipentaerythritol pentaacrylate (abbreviation: DPPA, hydroxyl group content: 0.18), and the like.

The hard coat layer 3 may contain various known additives. For example, antistatic agents, antistatic agents, ultraviolet absorbers, and silica having a reactive group. For example, by adding a flame retardant agent, the hard coat layer can be also used as the antiglare layer, and the antireflection film can be used as the antireflection film. Organic and inorganic dispersing agents may be used for the dispersion.

In order to prevent interference non-uniformity occurring at the interface between the hard coat layer and the transparent base film (1), the hard coat layer (3) is preferably such that the composition of at least part of the coating liquid used for the hard coat layer .

Since the hard coat layer 3 is formed as a hardened layer of an ionizing radiation curable resin in the same manner as the low refractive index layer, the hard coat layer 3 can be formed by using the resin composition as a coating material or ink It can be formed by applying it on a transparent base film and then curing the resin by irradiation with ionizing radiation. The coating method is not particularly limited, and a known coating method as disclosed in the low refractive index layer may be suitably employed.

When the hard coat layer 3 is formed, the low refractive index layer is formed on the hard coat layer. However, when the low refractive index layer is formed, the hard coat layer is not completely cured, It is preferable that the resin of the coat layer is completely cured from the viewpoint of adhesion of both layers. By improving the adhesion between the interface between the hard coat layer and the low refractive index layer, the hardness and scratch resistance of the outermost surface of the antireflection film can be improved.

B. Polarizer

The polarizing plate of the present invention is a polarizing plate in which the above-mentioned antireflection film of the present invention is laminated on at least one side of the polarizer toward the polarizer. Here, FIG. 2 is a sectional view showing one form of the polarizing plate. In the polarizing plate 20 shown in the same figure, the antireflection film 10 of the present invention is laminated on the polarizer 4 on the side of the transparent base film 1 so that the low refractive index layer surface 2s is the outermost surface . The antireflection film 10 is laminated on one side of the polarizer 4 and the other side of the polarizer 4 is a laminated structure of the protective film 5 other than the antireflection film 10 of the present invention .

The surface of the polarizing plate 20 on the side of the antireflection film 10 is exposed to air to prevent reflection of light entering the polarizing plate. On the other hand, since the surface of the polarizing plate on the side of the protective film 5 is generally laminated on another optical member such as a liquid crystal cell by a pressure sensitive adhesive layer or the like, the surface on the protective film side needs to be antireflection- none. In the polarizing plate of the present invention, the above-mentioned antireflection film of the present invention may be laminated on both sides of the polarizer toward the polarizer.

[Polarizer]

The polarizer 4 is not particularly limited and may be any conventionally known polarizer in a polarizing plate. For example, a polyvinyl alcohol film which is dyed and stretched by iodine or the like. In addition to the polyvinyl alcohol film, the film to be dyed and stretched may be a polyvinyl formal film, a polyvinyl acetal film, or an ethylene-vinyl acetate copolymerization system saponified film.

[Protection film]

The protective film 5 is laminated on a polarizer opposite to the surface on which the antireflection film is laminated. The same film as that of the transparent base film in the antireflection film can be used. Therefore, as the protective film, it is preferable to use a transparent film made of triacetylcellulose. In addition, from the viewpoint of preventing curling and the like, a film of the same kind is preferable. Therefore, further explanation is omitted. This protective film is a film which is permanently bonded and laminated, unlike the temporary saponification protective film which is temporarily adhered as described in the Background of the Related Art section.

[Lamination of polarizer and antireflection film and protective film]

In lamination of the polarizer 4, the antireflection film 10 and the protective film 5, it is preferable to conduct the so-called saponification treatment with an aqueous alkaline solution because the adhesion between the polarizer and the film can be enhanced Do. Particularly, the antireflection film of the present invention has anti-saponification property and is therefore also preferable in that it can exert its advantages.

C. Image display device

The image display apparatus according to the present invention is an image display apparatus having the above-described antireflection film of the present invention or the polarizing plate of the present invention. The antireflection film or the polarizing plate may be provided on the observer side of the display panel, for example. The antireflection film or the polarizing plate may be a display panel in which the display panel and the display panel are integrally laminated and integrated, or may be disposed on the observer side of the display panel with an air layer interposed therebetween.

The display panel is not particularly limited and may be a known display panel. For example, a display panel such as a cathode ray tube (CRT), a liquid crystal panel, a plasma display panel, an electro luminescence panel, a touch panel, .

The antireflection film and the polarizing plate are usually provided with a polarizing plate when the display panel of the image display apparatus is a liquid crystal panel. When the polarizing plate is basically an unnecessary display panel, for example, a plasma display panel, an electroluminescence panel, a cathode ray tube (CRT), a touch panel, an electronic paper, a tablet PC, etc., the image display device is provided with an antireflection film.

The image display apparatus of the present invention may include other known components such as a display drive circuit, a wiring, a chassis, a frame, an input / output component, and a cabinet, depending on the use.

〔Usage〕

The use of the image display apparatus according to the present invention is not particularly limited, and examples thereof include a television receiver, a monitor display, an electronic signboard, a portable information terminal, a digital photo frame, and a medical apparatus.

[Example]

Hereinafter, the present invention will be further described with reference to Examples, Comparative Examples and Reference Examples. In the following, the materials used or abbreviations thereof are as follows. The term " part " means all of the parts by mass.

[Polymerizable compound (all polyfunctional polymerizable compound)]

Hereinafter, abbreviations of the used materials, the number of functional groups of the polymerizable functional group (acryloyl group), the molecular weight, the presence or absence of the hydroxyl group (OH group), and the like will be described.

≪ Compound containing no hydroxyl group >

TMPTA: trifunctional, molecular weight 296, trimethylolpropane triacrylate (100% solids)

NK ester: hexafunctional, Mw 578, dipentaerythritol hexaacrylate; DPHA (Shin-Nakamura Chemical Industry Co., Ltd.) (solid content: 100%)

UV1700B: 10-functional oligomer (manufactured by Nippon Gosei Chemical Industry Co., Ltd., solids content: 100%) obtained by reacting DPPA with an isocyanate group of IPDI (isophorone diisocyanate) having a molecular weight of about 2000 and a molecular weight of about 2000;

<Compounds Containing a Hydroxyl Group>

· PETA: trifunctional, Mw 298, OH number 1, OH content 0.33, pentaerythritol triacrylate (containing one hydroxyl group)

DPPA: pentafunctional, molecular weight of about 550, OH group number of 1, OH content of 0.18, dipentaerythritol pentaacrylate (trade name: KAYALAD (registered trademark) DPHA, manufactured by Nippon Kayaku Kabushiki Kaisha, solid content: 100%

DPPMA: a 6-functional, Mw of about 550, a mixture of dipentaerythritol pentaacrylate and dipentaerythritol penta methacrylate

· V802: 7 to 9 functional group, molecular weight 700 to 1000, OH group number 1, OH content 0.10 to 0.14, a polymer of DPPA (manufactured by Osaka Kikin Kagaku Kogyo Kabushiki Kaisha, solid content: 100%

[solvent]

MIBK: methyl isobutyl ketone

PGMEA: Propylene glycol monomethyl ether acetate

PGME: Propylene glycol monomethyl ether

[Hollow silica particles treated with surface water]

(Silica particles having an average particle diameter of 55 nm and a surface treated with a hydrophobic treatment, 20% solids, MIBK dispersion)

[Photopolymerization initiator]

(2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} - (2-hydroxy- 2-methyl-propan-1-one

[Antifouling agent]

TU2225 (fluorine-containing silicone antifouling agent, manufactured by JSR Corporation, solid content: 15%)

The measurement of the molecular weight of the above compound is the same as that described in the column of (ionic weight) of the above [ionizing radiation curable resin], but for those having a molecular weight of more than 1000, for example, Shodex (registered trademark) GPC KF- 801, GPC KF-802, GPC KF-803, GPC KF-804, GPC KF-805 and GPC KF-800D (all manufactured by Showa Denko K.K.).

[Test evaluation method]

The performance before and after the saponification treatment was measured and evaluated with respect to four kinds of abrasion resistance, antifouling property, antireflection property, whitening resistance, and appearance.

[Scratch resistance]

The scratch resistance was evaluated by the hardness of the steel. By this evaluation, not only the hardness of the surface but also the adhesion between the low refractive index layer and the ground layer and the peeling of the coating film can be evaluated at the same time. Specifically, the surface of the low refractive index layer was subjected to reciprocating rubbing 10 times using a steel wool # 0000 at a predetermined friction load of 300 g / cm 2, and thereafter the presence or absence of peeling of the coating film was visually observed and evaluated according to the following criteria.

○; No scratches (No peeling of coating film at all)

×; Scratches (peeling of coating film is present)

[Antifouling property]

The antifouling property was evaluated by the following criteria after wiping with the oil-based marking pen on the surface of the low refractive index layer and then wiping 20 times with the cellulose-based nonwoven fabric wiper.

○; Wipe

X: Not wiped

[Antireflection property]

In order to prevent reflection, a black tape for preventing the reflection of the back surface was attached to the surface of the transparent base film on the side where the low refractive index layer was not formed, and the surface of the low refractive index layer was set as the light source side, and a spectral reflectance meter (Shimazu Seisaku Co., PC-3100) was used, and the lowest reflectance in a wavelength region of 380 to 780 nm was measured as a light reflectance, and evaluated by the following criteria.

○; When the light reflectance is 1.0 to 2.0%

×; (2.0% or more) or more than 2.0% even before the saponification treatment after the saponification treatment,

[White Mars]

As a whitening resistance before and after the saponification treatment, the anti-saponification durability was evaluated so that the produced antireflection film did not show a whitish appearance. In the whitening agent, a black tape for preventing the reflection of the back surface was attached to the surface of the transparent base film on the side where the low refractive index layer was not formed, and the surface of the low refractive index layer in the dark room was irradiated with the light of a fluorescent lamp And whether or not whitening occurred was visually observed from the 45-degree position from the surface, and evaluated according to the following criteria.

○; No bleaching

×; With white papers

[Exterior]

The outer appearance of the antireflection film was evaluated by attaching a black tape to the surface of the transparent base film on the side where the low refractive index layer of the produced antireflection film was not formed and irradiating the light of the tri-wavelength type fluorescent lamp from the side where the low refractive index layer was formed The surface was visually observed and evaluated according to the following criteria.

○: No change in color before and after saponification treatment

X: Change in color before and after saponification

[Saponification treatment]

The saponification treatment was performed under the following two conditions. Usually, the saponification treatment is slowly immersed in a low-concentration low-temperature alkali solution, or rapidly immersed in a high-concentration, high-temperature alkali solution. The latter condition has a shorter immersion time, but since the antireflection film is a severe treatment, the condition B below is better than that under condition A.

Condition A: The substrate was immersed in an aqueous 2N NaOH solution at a temperature of 50 ° C for 3 minutes.

Condition B: The substrate was immersed in an aqueous 4 NaOH solution at 60 캜 for 30 seconds.

[Example 1]

The composition for a hard coat layer (A) containing the following ionizing radiation curable resin was applied to one side of a transparent triacetyl cellulose film (TAC film, refractive index: 1.48) having a thickness of 80 탆 as a transparent base film, (Semi-cured) to form a hard coat layer having a thickness of 10 mu m.

Subsequently, the following composition (1) for a low refractive index layer was coated on the formed hard coat layer, and then the resin was cured by ultraviolet irradiation to form a low refractive index layer having a thickness of 100 nm and the hard coat layer was completely cured An antireflection film was produced. Subsequently, saponification treatment was carried out under the saponification treatment condition A.

[Composition (A) for hard coat layer]

Dipentaerythritol hexaacrylate (DPHA, 6-functional) 100 parts

solvent; MIBK 70

solvent; PGMEA 30 copies

Photopolymerization initiator 0.4 part

[Composition (1) for low refractive index layer]

TMPTA 100 parts

Hollow silica particles (solid content, the same applies hereinafter) 100 parts

solvent; MIBK 70

solvent; PGMEA 30 copies

Antifouling Part 4

Photopolymerization initiator 7 parts

[Example 2]

The anti-reflection film produced in Example 1 was subjected to saponification treatment under the saponification treatment condition B.

[Example 3]

An antireflection film was produced in the same manner as in Example 1 except that the following composition (2) for a low refractive index layer, which had different resin components, was used to form the low refractive index layer in Example 1, Lt; / RTI &gt;

[Composition (2) for a low refractive index layer]

DPPA 100 parts

Hollow silica particles 100 parts

solvent; MIBK 70

solvent; PGMEA 30 copies

Antifouling Part 4

Photopolymerization initiator 7 parts

[Example 4]

 An antireflection film was produced in the same manner as in Example 1 except that the following composition for a low refractive index layer (3) having different resin components was used to form the low refractive index layer in Example 1, Lt; / RTI &gt;

[Composition (3) for a low refractive index layer]

NK ester (6-functional DPHA) 100 parts

Hollow silica particles 100 parts

solvent; MIBK 70

solvent; PGMEA 30 copies

Antifouling Part 4

Photopolymerization initiator 7 parts

[Example 5]

An antireflection film was produced in the same manner as in Example 1 except that the following composition for low refractive index layer (4) having different resin components was used to form the low refractive index layer in Example 1, Lt; / RTI &gt;

[Composition (4) for a low refractive index layer]

V802 100 parts

Hollow silica particles 100 parts

solvent; MIBK 70

solvent; PGMEA 30 copies

Antifouling Part 4

Photopolymerization initiator 7 parts

[Example 6]

An antireflection film was produced in the same manner as in Example 1 except that the following composition for a low refractive index layer (5) having different resin components was used for forming the low refractive index layer in Example 1, Lt; / RTI &gt;

[Composition (5) for low refractive index layer]

DPPMA 100 parts

Hollow silica particles 100 parts

solvent; MIBK 70

solvent; PGMEA 30 copies

Antifouling Part 4

Photopolymerization initiator 7 parts

[Example 7]

An antireflection film was produced in the same manner as in Example 1 except that the following composition for a low refractive index layer 6 in which the resin component was different from the mixed resin was used for forming the low refractive index layer in Example 1, Was saponified under the same conditions.

[Composition (6) for low refractive index layer]

TMPTA 75 parts

DPPA 25 pts

Hollow silica particles 100 parts

solvent; MIBK 70

solvent; PGMEA 30 copies

Antifouling Part 4

Photopolymerization initiator 7 parts

[Example 8]

An antireflection film was produced in the same manner as in Example 1 except that the following composition for a low refractive index layer (7) having different resin components as the mixed resin was used for forming the low refractive index layer in Example 1, Was saponified under the same conditions.

[Composition (7) for a low refractive index layer]

V802 75 parts

DPPA 25 pts

Hollow silica particles 100 parts

solvent; MIBK 70

solvent; PGMEA 30 copies

Antifouling Part 4

Photopolymerization initiator 7 parts

[Example 9]

An antireflection film was produced in the same manner as in Example 1 except that the following composition for a low refractive index layer (8) having different resins and solvents was used for forming the low refractive index layer in Example 1, Lt; / RTI &gt;

[Composition (8) for a low refractive index layer]

TMPTA 75 parts

DPPA 25 pts

Hollow silica particles 100 parts

Solvent: MIBK 70 parts

Solvent: PGME 30 parts

Antifouling Part 4

Photopolymerization initiator 7 parts

[Example 10]

An antireflection film was produced in the same manner as in Example 1 except that the following composition for low refractive index layer (9) having different amounts of hollow silica particles was used for forming the low refractive index layer in Example 1, 1 under the same conditions.

[Composition (9) for a low refractive index layer]

TMPTA 100 parts

Hollow silica particles 120 parts

Solvent: MIBK 70 parts

solvent; PGMEA 30 copies

Antifouling Part 4

Photopolymerization initiator 7 parts

[Comparative Example 1]

Except that the following composition for a low refractive index layer (10) containing a polyfunctional polymerizable compound having a hydroxyl group content of more than 0.2 was used in the formation of the low refractive index layer in Example 1, And a saponification treatment was carried out under the same conditions as in Example 1. Then,

[Composition (10) for a low refractive index layer]

PETA 100 parts

Hollow silica particles 100 parts

solvent; MIBK 70

solvent; PGMEA 30 copies

Antifouling Part 4

Photopolymerization initiator 7 parts

[Comparative Example 2]

The anti-reflection film produced in Comparative Example 1 was subjected to saponification treatment under the saponification treatment condition B.

[Comparative Example 3]

Except that the following composition for a low refractive index layer (11) containing a multifunctional polymerizable compound having a hydroxyl group content of more than 0.2 and having different solvent components was used in the formation of the low refractive index layer in Example 1, 1, an antireflection film was prepared and subjected to a saponification treatment under the same conditions as in Example 1.

[Composition (11) for a low refractive index layer]

PETA 100 parts

Hollow silica particles 100 parts

solvent; MIBK 85

solvent; PGME 15 part

Antifouling Part 4

Photopolymerization initiator 7 parts

[Comparative Example 4]

In Example 1, in the formation of the low refractive index layer, the ratio of the total number of electrons to the total amount of the resin components was 50, including the multifunctional polymerizable compound having a hydroxyl group content of more than 0.2 and the multifunctional polymerizable compound having a hydroxyl group content of 0.2 or less An antireflection film was produced in the same manner as in Example 1 except that the following composition (12) for a low refractive index layer was used in an amount of not less than 1 mass% and saponified under the same conditions as in Example 1.

[Composition (12) for a low refractive index layer]

PETA 75 parts

DPPA 25 pts

Hollow silica particles 100 parts

solvent; MIBK 70

solvent; PGME 30 parts

Antifouling Part 4

Photopolymerization initiator 7 parts

[Comparative Example 5]

In Example 1, in the formation of the low refractive index layer, the ratio of the total number of electrons to the total amount of the resin components was 50, including the multifunctional polymerizable compound having a hydroxyl group content of more than 0.2 and the multifunctional polymerizable compound having a hydroxyl group content of 0.2 or less An antireflection film was produced in the same manner as in Example 1 except that the composition (13) for a low refractive index layer described below was used in an amount of not less than 1 mass% and saponified under the same conditions as in Example 1.

[Composition (13) for a low refractive index layer]

PETA 75 parts

V802 25

Hollow silica particles 100 parts

solvent; MIBK 70

solvent; PGME 30 parts

Antifouling Part 4

Photopolymerization initiator 7 parts

[Comparative Example 6]

The procedure of Example 1 was repeated except that the following composition for a low refractive index layer (14) was used, which contained a multifunctional polymerizable compound having a different resin component and a molecular weight of more than 1000 in the formation of the low refractive index layer. Similarly, an antireflection film was prepared and subjected to saponification under the same conditions as in Example 1.

[Composition (14) for a low refractive index layer]

UV1700B 100 parts

Hollow silica particles 100 parts

solvent; MIBK 70

solvent; PGMEA 30 copies

Antifouling Part 4

Photopolymerization initiator 7 parts

[Performance evaluation result]

The contents of the polymerizable compounds used in the above Examples and Comparative Examples are shown in Tables 1 and 2, and the performance evaluation results are shown in Tables 2 and 3 below.

As shown in Table 1, in the polymerizable compound constituting the ionizing radiation curable resin of the low refractive index layer, the total amount of the multifunctional polymerizable monomer not containing a hydroxyl group Example 4, which used trifunctional TMPTA as a functional compound in Examples 1 to 2 and Example 10, and 6-functional NK ester (DPHA) as a polyfunctional polymerizable compound containing no hydroxyl group in all, , All of scratch resistance, antifouling property, antireflection property, whitening resistance, and appearance were all satisfactory. Also, Example 2 in which the saponification treatment was carried out under Condition B was also satisfactory in the saponification resistance.

A multifunctional polymerizable compound having a hydroxyl group in the polymerizable compound constituting the ionizing radiation curable resin of the low refractive index layer is used. However, when the number of hydroxyl groups per molecule is 1 or less and the hydroxyl group content is 0.2 or less, In Example 3 of DPPA, Example 4 of V802, and Example 6 of DPPMA, all of scratch resistance, antifouling property, antireflection property, whitening resistance and appearance were all satisfactory.

A multifunctional polymerizable compound having a hydroxyl group is used but it is also possible to use a compound having a hydroxyl group content of not more than 1 and a hydroxyl group content of not more than 0.2 in one molecule, In all of Examples 7 to 9, scratch resistance, antifouling property, antireflection property, whitening resistance, and appearance were both satisfactory.

As described above, in Examples 1 to 10, it is considered that the saponification resistance is satisfactory in all the evaluations, and that the resin of the low refractive index layer remains without dissolving or falling off in the saponification treatment.

On the other hand, in Comparative Examples 1 to 5 using PETA which is a polyfunctional polymerizable compound having a hydroxyl group and a hydroxyl group content of more than 0.2 in the polymerizable compound constituting the ionizing radiation curable resin of the low refractive index layer, The antimicrobial resistance, whitening resistance and appearance were all after the saponification treatment, and the saponification resistance was satisfactory. However, in Comparative Examples 1 to 5, scratch resistance, antifouling property and appearance were not satisfactory after the saponification treatment, and the saponification resistance was not satisfactory. Comparative Example 4 and Comparative Example 5 in which a multifunctional polymerizable compound having no hydroxyl group together with a multifunctional polymerizable compound having a hydroxyl group were used together in the range of the subcomponent (less than 50% by mass of the entire resin component) Since the amount of the polymerizable compound having no hydroxyl group was small and the amount of the hydroxyl group as a whole was large in the resin composition, scratch resistance, antifouling property and appearance became X after the saponification treatment.

In Comparative Example 6 in which the hydroxyl group was not contained in the polyfunctional polymerizable compound and the content of the hydroxyl group was 0, but the urethane type oligomer type compound having a hydroxyl group was used, the number of functional groups of the acryloyl group exceeded 10 and 9 In addition, since the molecular weight (weight average) exceeded 1000 by 1000, the antifouling property was ○ even after the saponification treatment, but the scratch resistance, antireflection property, whitening property and appearance were unsatisfactory after the saponification treatment.

When the frictional load is evaluated by increasing the frictional load from 300 g / cm 2 to 600 g / cm 2, Examples 1 and 2 after saponification are as good as before the load increase, but Examples 3 to 10 fall within the permissible range but slightly decrease. Therefore, the resin had the best TMPTA of 100%.

Although not shown in Table 1, the adhesiveness between the transparent base film and the hard coat layer was good in both Examples and Comparative Examples. This adhesion was performed in accordance with the lattice tape method of JIS K5400, and the gratings were not peeled off.

1: transparent substrate film
2: low refractive index layer
2s: low refractive index layer surface
3: Hard coat layer (functional layer)
4: Polarizer
5: Protective film
10: Antireflection film
20: polarizer

Claims (4)

A transparent base film made of triacetyl cellulose,
A low refractive index layer which is formed on one side of the transparent base film and has a refractive index lower than that of the lower layer which is composed of a cured layer of the first ionizing radiation curable resin and contains hollow silica particles,
And a functional layer provided between the transparent base film and the low refractive index layer
The anti-reflection film according to claim 1,
Wherein the functional layer is a hard coating layer comprising a cured layer of a second ionizing radiation curable resin,
Wherein the polymerizable compound contained in the first ionizing radiation curable resin is any one of the following (A) and (B)
(A) a multifunctional polymerizable compound having no hydroxyl group in the molecule, and at least one of diethylene glycol di (meth) acrylate, isocyanuric acid-modified tri (meth) acrylate and ditrimethylolpropane tetraacrylate A polyfunctional polymerizable compound,
(B) a multifunctional polymerizable compound having a hydroxyl group in a molecule and having a hydroxyl group content defined as a value obtained by dividing the number of hydroxyl groups contained in one molecule by the molecular weight by 100,
The polyfunctional polymerizable compound in the above (A) and (B) has a functional group number of 3 to 9, a molecular weight of 300 to 1000,
Wherein the polymerizable compound contained in the second ionizing radiation curable resin is a polyfunctional polymerizable compound having no hydroxyl group in the molecule. Wherein the antireflection film according to claim 1 is laminated on at least one side of the polarizer with its transparent base film side facing the polarizer. An image display device comprising the antireflection film according to claim 1 or the polarizing plate according to claim 2. delete

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