KR20080107302A - Anti-reflection film and front plate for display panel using the same - Google Patents

Abstract

An anti-reflection film is provided to have excellent reflection preventing function by preventing generation of the interference stain. An anti-reflection film including anti-reflective layer which is arranged on one main surface side(10a) of the polyester and a polyester by a wet coating method. An anti-reflective layer includes a hardcoating layer(11) from the polyester member and a low refractive index layer(12) arranged in the upper than the hardcoating layer. The hardcoating layer is installed on the polyester member includes a metal oxide and rate of the metal oxide is 20 volume %-42 volume %.

Description

Anti-reflection film and front panel for display using the same {ANTI-REFLECTION FILM AND FRONT PLATE FOR DISPLAY PANEL USING THE SAME}

The present invention relates to an antireflection film provided with an antireflection layer and a front panel for a display using the same.

In recent years, development of the high definition large-size display represented by a liquid crystal display, a plasma display panel (PDP), etc. is progressing rapidly. In order to improve the visibility of the display, it is necessary to arrange an antireflection layer having an antireflection function on the surface in order to prevent external light such as a fluorescent lamp on a screen.

As a method of forming an antireflection layer, a so-called dry coating method and a low refractive index material, which deposit or sputter an inorganic metal on the surface of a display, are applied to a substrate in a liquid such as a solution or a dispersion, dried, and cured as necessary to prevent reflection. The wet coating method etc. which manufacture the film etc. which have a function are known. With the recent increase in the size of the display, the wet coating method which is inexpensive by Roll-to-Roll (roll to roll) and which is easy to cope with the enlargement of the size is becoming the mainstream. In other words, the price competition of televisions using a high-definition display such as a liquid crystal display or a plasma display panel (PDP) is fierce internationally, and the productivity and the cost are high due to the deposition or sputtering of inorganic metal. Inexpensive and easy to cope with large-scale wet coating method is the mainstream, but further cost reduction is always required even in the anti-reflection film produced by the wet coating method. Therefore, in the case of manufacturing an optical film having the same function in the wet coating method, for example, an antireflection film, etc., an antireflection film capable of reducing the manufacturing process, specifically, fewer layers or processing steps are produced. It is possible to further reduce the cost of the antireflection film having the necessary function and quality.

The antireflection layer formed by the wet coating method includes a hard coat layer for increasing the hardness of the substrate itself, and a single layer or a double layer having a film thickness of about 100 nm, respectively, on the transparent substrate film to increase the hardness of the substrate itself. There is a film (patent document 1).

Moreover, as a transparent base film, the polyester resin film, especially the biaxially stretched film of polyethylene terephthalate (PET), is used frequently. Since a biaxially stretched PET film has transparency and excellent mechanical properties, flame resistance or chemical resistance, etc., elongation of demand is remarkable as a base film of the said antireflection film.

However, such a polyester substrate is generally difficult to maintain good adhesion with the antireflection layer, and, for example, in order to improve the adhesion between the PET film and the antireflection layer when a biaxially stretched PET film is used as the transparent substrate. A primer layer (also called an anchor coat layer) for imparting easily adhesiveness, also referred to as an easily adhesive layer, on the surface of a PET film. Hereinafter, the primer layer for imparting easy adhesiveness is not particularly limited. In most cases, a simple “primer layer” is provided. That is, in the case of forming the anti-reflection layer on the PET film by wet coating method, in actual production, for example, Patent Document 2 or Patent Document 3 of the patent document 3 to be described later, As described in [0024] of Document 4, [0004] of Patent Document 5, and [0003] of Patent Document 6, a primer layer is formed on the main surface side of the at least antireflection layer of the PET film as an easily adhesive layer, or it is formed. It is a phenomenon that the PET film used is used.

However, in the antireflection layer in which the relationship between the film thickness and the refractive index of each layer provided on the substrate is very important, the primer layer also greatly influences the antireflection performance, and the three refractive indices and the film thicknesses of the substrate, the primer layer, and the antireflection layer are changed. It is necessary to consider and design (patent document 2-patent document 4).

However, this optical design is difficult and it is difficult to suppress the occurrence of interference spots. In addition, the provision of a primer layer in addition to the hard coat layer and the low refractive index layer will increase the manufacturing process, making it difficult to respond to the low cost demands of the market.

As a method other than providing the primer layer, an easy-adhesion surface pretreatment such as corona treatment or plasma treatment is performed on the polyester substrate ("Easi-adhesion surface pretreatment" does not separately form a new layer such as a primer layer, but the surface of the substrate). It is also proposed to carry out a treatment to improve the adhesiveness by modifying the adhesive), but it is difficult to achieve sufficient adhesiveness only by corona treatment or plasma treatment (Patent Document 5).

On the other hand, by using specific resin for hard-coat layer formation, it is proposed to improve adhesiveness with a polyether resin base material without providing a primer layer (patent document 6). However, in this method, the adhesion between the substrate and the hard coat layer is not sufficient.

[Patent Document 1]

Japanese Patent Application Laid-Open No. 2002-200690

[Patent Document 2]

JP 2003-177209 A

[Patent Document 3]

Japanese Patent Application Laid-Open No. 2004-345333

[Patent Document 4]

Japanese Patent Application Laid-Open No. 2006-258897

[Patent Document 5]

Japanese Patent Application Laid-Open No. 2006-235125

[Patent Document 6]

Japanese Patent Application Laid-Open No. 2005-196065

Therefore, the present invention can secure the adhesiveness between the polyester substrate and the antireflection layer even when a polyester substrate having no primer layer is used on the main surface side on which the antireflection layer is formed, and also prevents occurrence of interference spots. It is an object of the present invention to provide an antireflection film having excellent antireflection performance and a front plate for display using the antireflection film.

(1) In order to solve the said subject, the antireflection film of this invention is an antireflection film containing a polyester base material and the antireflection layer arrange | positioned by the wet-coating method in the one main surface side of the said polyester base material,

The antireflection layer includes a hard coat layer and a low refractive index layer disposed above the hard coat layer from the polyester substrate side,

The hard coat layer is provided directly on the polyester substrate,

The hard coat layer comprises a metal oxide, characterized in that the ratio of the metal oxide is 20% by volume to 42% by volume.

(2) In the antireflection film as described in said (1), it is preferable that the said main surface of the said polyester base material on which the said antireflection layer is arrange | positioned is a polyester base material which is not pre-adhesion-surface pretreated.

(3) In the antireflection film as described in said (1) or (2), the said polyester base material is a cross cut adhesive test by the said antireflection layer based on JISK5600-5-6. It is preferable that it is an antireflection film from which peeling cannot be confirmed.

(4) In the antireflection film in any one of said (1)-(3), it is preferable that the maximum value of the difference of the amplitude of the reflectance in 380 nm-780 nm of the said antireflection film is 1.0% or less. .

(5) In the antireflection film in any one of said (1)-(4), it is preferable that a near-infrared absorption layer is arrange | positioned at the other main surface side of the said polyester base material.

(6) Moreover, the antireflection film in any one of said (1)-(5) is arrange | positioned on the board | substrate for the display front plate of this invention. It is characterized by the above-mentioned.

(1) According to the present invention, the adhesion between the polyester base material and the antireflection layer can be ensured, and the occurrence of interference spots can be prevented, and an antireflection film excellent in antireflection performance can be provided. Since the hard coat layer is directly provided on the polyester substrate without passing through a primer layer for easy gluing, the hard coat layer does not require the formation of a primer layer, so that an inexpensive antireflection film can be provided. Moreover, even without the said primer layer, adhesiveness of a polyester base material and an antireflection layer can be ensured.

(2) Moreover, in the antireflection film of said (1), in the preferable aspect of this invention whose said polyester base main surface of the side which arrange | positions the said antireflection layer is a polyester base material which is not pre-adhesion-surface pretreated. By doing so, since the adhesion between the polyester base material and the antireflection layer can be ensured even without the pre-adhesion surface pretreatment, the low-adhesion surface pretreatment may be omitted, thereby providing an inexpensive antireflection film. In the present invention according to claim 1, the use of a polyester base material on which an tackified surface pretreatment is not excluded.)

(3) In the antireflection film according to (1) or (2), in the checkerboard scale peeling test performed by the antireflection layer based on JIS K5600-5-6, the peeling from the polyester base material is performed. By setting it as the preferable aspect of this invention which was not confirmed, the antireflection film excellent in the quality reliability which does not produce peeling of an antireflection layer can be provided.

(4) Moreover, in the antireflection film as described in any one of said (1)-(3), the maximum value of the difference of the amplitude of the reflectance in 380 nm-780 nm of the said antireflection film is 1.0% or less. By setting it as the preferable aspect of this invention, the antireflection film with little generation | occurrence | production of interference spots can be provided.

(5) Moreover, in the antireflection film in any one of said (1)-(4), it is set as the preferable aspect of this invention by which the near-infrared absorption layer is arrange | positioned at the other main surface side of the said polyester base material. The anti-reflective film provided with this near-infrared absorbing layer is provided on the front surface of the plasma display panel (PDP) used as a display panel for various electronic devices including large-sized televisions. It can further function as a filter for shielding unnecessary near-infrared rays generated in the above, and is suitable for preventing the problem of causing malfunction of peripheral electronic devices such as televisions or air conditioners due to leakage of the near-infrared rays. An antireflection film having an antireflection function can be provided.

(6) Moreover, since the antireflection film in any one of said (1)-(5) is arrange | positioned on the board | substrate, the front plate for display of a display of the present invention is more cost-effective. The front plate for a display which can provide and also exhibits the function corresponding to each of said (1)-(5) with respect to an antireflection film layer can be provided.

As for the polyester base material used by the antireflection film of this invention, it is preferable that the light transmittance of visible region is 80% or more, and 88% or more is more preferable. Moreover, it is preferable that haze is 2.0% or less, and it is more preferable that it is 1.0% or less. Typical examples of the polyester base material include polyethylene terephthalate, polyethylene-2, 6-naphthalin dicarboxylate, and the like, but are particularly inexpensive but have transparency, excellent mechanical properties, flame resistance (non-burning properties), and chemical resistance. Since it has a etc., the biaxially stretched film of polyethylene terephthalate (PET) is preferable. The thickness of the said base material is about 10-500 micrometers normally.

Moreover, additives, such as antioxidant, a flame retardant, a heat resistant inhibitor, a ultraviolet absorber, and a lubricant, may be added to resin which comprises the said polyester base material.

The coating material for forming the hard coat layer may be adjusted by combining ionizing radiation curable resins, conductive and / or nonconductive metal oxide fine particles, photoinitiators, solvents, and the like, which are exemplified in the following, and are already mixed and combined to inkize them. You may use that. What is necessary is just to disperse | distribute according to the general adjustment method of coating liquid, in order to adjust the hard-coat layer coating material using the following component.

It is necessary to design the refractive index of the hard coat layer in consideration of the relationship of the refractive index with the base material. For example, the refractive index of PET substrate which is a polyester substrate is about 1.66. If the refractive index of the hard coat layer provided thereon differs greatly with respect to this, it will cause an interference spot. Usually, when the difference in refractive index between a hard coat layer and a base film is ± 0.03 or more, interference spots are said to occur. Therefore, the refractive index of the hard coat layer is preferably 1.60 to 1.70. By adding a metal oxide with a large refractive index, the refractive index of the hard coat layer approaches the base film. One type of metal oxide may be used and two or more types may be used.

Moreover, in the antireflection film of this invention, when the maximum value of the difference of the amplitude of the reflectance in 380 nm-780 nm of the said antireflection film is 1.0% or less, it can provide the antireflection film with little occurrence of interference spots. have. For this purpose, it is preferable to make the difference of the refractive index of a polyester base material and the refractive index of the hard-coat layer provided on it become smaller than +/- 0.03, and since the refractive index of a polyester base material cannot be changed easily, it is usually hard The maximum difference in the amplitude of the reflectance at 380 nm to 780 nm of the antireflection film obtained by adjusting the refractive index of the hard coat layer by selecting and combining materials constituting the coat layer, that is, ionizing radiation curable resin and metal oxide fine particles. The value can be 1.0% or less.

By using an electroconductive metal oxide for the metal oxide used for a hard-coat layer, an antireflective film can also be made to have antistatic performance. In order to make prescribed refractive index only by one type of electroconductive metal oxide, content of the metal oxide in a hard-coat layer may increase. Therefore, in this case, by using two or more kinds of metal oxides, the refractive index can be increased so that the content of the metal oxides does not become too high.

Moreover, a hard-coat layer is formed using resin containing ionizing radiation hardening type resin. Thereby, a hard coat layer can be formed reasonably.

Examples of the metal oxide contained in the hard coat layer include antimony dope tin oxide (ATO), indium dope tin oxide (ITO), phosphorus dope tin oxide (PTO), zinc oxide (ZnO), and tin oxide (SnO _2). ), Zirconium oxide (ZrO ₂ ), zinc antimonate (ZnSb ₂ O ₆ ), and the like. A fine particle is suitably used for this metal oxide, 100 nm or less is preferable, as for the average particle diameter, 50 nm or less is more preferable, 20 nm or less is especially preferable. It is because dispersibility in ionizing radiation hardening type resin improves that it is in this range, and the haze at the time of coating film formation becomes small. Although there is no restriction | limiting in particular in the minimum of the average particle diameter of a metal oxide, 2.0 nm or more is preferable from a viewpoint of electroconductive expression or high refractive index expression.

In addition, the measurement of the average particle diameter of these metal oxide particles cuts the anti-reflective film containing a metal oxide particle with a microtome, and takes a TEM (transmission electron microscope) photograph of 200,000 times the magnification of the cut film cross section. The average value of the particles of 300 is defined as the average particle diameter. If the photographed particles are not spherical and have a long diameter and a simple diameter, the long diameter and the simple diameter are measured by one particle, and these averages are calculated. This average value is measured and calculated for 300 particles to be the average particle diameter.

It is important in the present invention that the content ratio of the metal oxide to the hard coat layer is 20% by volume to 42% by volume, more preferably 25% to 35% by volume. By making the content rate of the metal oxide in a hard-coat layer into the said range, the adhesiveness of a hard-coat layer with respect to a polyester-base main surface is not formed, without forming a primer layer in the main surface where the hard-coat layer of a polyester base is provided. It can be made to be practical and strong, and can also be made high in strength as a coating film. If the ratio of the metal oxide to the hard coat layer is too small, it is estimated that the volume shrinkage at that time is large and easily peels off from the polyester substrate. On the other hand, if the ratio of the metal oxide to the hard coat layer is too large, as the coating film, Not only the strength is lowered, but too much, it is difficult to even form a coating film. Therefore, by setting the above range, the adhesiveness of the hard coat layer to the main surface of the polyester base can be used without forming a primer layer. In addition, since the primer layer is not provided on the main surface on which the hard coat layer of the polyester base is installed, it is possible to prevent the occurrence of interference spots and to provide an antireflection film having excellent antireflection performance. Can provide.

In addition, the ratio of the said metal oxide refers to the volume of the metal oxide with respect to the total volume of the metal oxide and resin solid content contained in a hard-coat layer. A volume ratio is calculated | required by calculation from the weight ratio of a metal oxide and resin solid content, and the specific gravity document value of each material.

As ionizing radiation hardening type resin which forms the said hard-coat layer, the monomer which has a vinyl group, a (meth) acryloyl group, an epoxy group, and an oxetanyl group, those prepolymers, and a polymer can be used. These can be used individually or in combination of 2 or more types. It is preferable to use a polyfunctional monomer and an oligomer from a viewpoint of both productivity and hardness. As the polyfunctional monomer or oligomer, a polyfunctional acrylic monomer having two or more unsaturated groups or an oligomer thereof is preferably used. Moreover, adhesiveness with a polyester base material improves if it has many bond groups and functional groups which form a hydrogen bond in a monomer and oligomer molecule. Moreover, the refractive index of a hard-coat layer can be made high by using high refractive index monomers and oligomers, such as bisphenol A modified (meth) acrylate.

As a polyfunctional acryl-type monomer and oligomer, for example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, 1,4-cyclohexanediacrylate , Pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, di Polyhydric alcohols, such as pentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, a 1, 2, 3-cyclohexane trimethacrylate, a polyurethane acrylate, polyester polyacrylate, and (meth) Esters produced from acrylic acid, 1,4-divinylbenzene, 4-vinylbenzoic acid-2-acryloylethyl ester, 1,4-divinylcyclohex Vinyl benzene, such as a stanone, its derivatives, etc. are mentioned. Although these may be used independently, you may use in combination of 2 or more type. Especially, at least 1 type chosen from pentaerythritol triacrylate and dipentaerythritol hexaacrylate from a viewpoint of further improving scratch resistance is preferable. Pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipenta About erythritol penta (meth) acrylate and dipentaerythritol hexa (meth) acrylate, it is preferable from a viewpoint of raising a film strength. Here, "… (meth) acrylate ..." means "... acrylate ..." and / or "... methacrylate ...".

When hardening the ionizing radiation curable resin contained in the said hard-coat layer, when performing ultraviolet irradiation, a photoinitiator is added to the coating liquid of a hard-coat layer. Examples of the photopolymerization initiator include acetphenones, benzophenones, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds, thiuram compounds, and fluoro Amine compounds and the like are used. These can be used individually or in combination of 2 or more types. As for the usage-amount of a photoinitiator, about 1-15 mass% is preferable with respect to the mass of the ionizing radiation hardening type resin normally used.

As other components of the composition of the hard coat layer, additives such as polymerization inhibitors, antioxidants, dispersants, surfactants, light stabilizers, and leveling agents may be added. Moreover, as long as it is made to dry after film-forming by the wet coating method, arbitrary amount of solvent can be added.

There is no restriction | limiting in particular about the method of forming a hard-coat layer on a polyester base material, It can form by apply | coating the coating liquid containing the said material on a polyester base material. The coating method is not particularly limited, for example, a coating method such as a roll coat, a die coat, an air knife coat, a blade coat, a spin coat, a reverse coat, a gravure coat, or a gravure print, a screen print, an offset print, an ink jet print, or the like. Can be used.

The surface hardness of the said hard-coat layer is evaluation by the pencil hardness test prescribed | regulated to JISK5600, H or more is preferable and it is more preferable that it is 2H or more.

Moreover, 0.3-3.0 micrometers is preferable, as for the thickness of a hard-coat layer, 0.3-2.0 micrometers is more preferable, 0.3-1.5 micrometers is more preferable.

When the thickness of the hard coat layer is less than 0.3 µm, the maintenance of hardness tends to be difficult. When the thickness of the hard coat layer exceeds 3.0 µm, cracking, curling (curvature of the film) occurs, or the total light transmittance of the antireflection film tends to be lowered, and further, ionization. There exists a tendency for the volume shrinkage of radiation curable resin to become large, and to make it easy to peel a hard-coat layer from a polyester base material. Therefore, the above range is preferable for the thickness of the hard coat layer.

The low refractive index layer disposed on the hard coat layer has an optical film thickness of λ / 4 (λ: wavelength of visible light of human being, in particular, wavelength of 550 nm of high visibility of human eye, which is a product of refractive index and film thickness). If it is set to the vicinity, a reflectance becomes further low and it is preferable.

The larger the difference between the refractive index of the low refractive index layer and the refractive index of the hard coat layer, the better the antireflection property. In addition, the low refractive index layer has strength and antifouling properties when placed on the outermost surface of the antireflection film of the present embodiment (that is, when no other functional layer is provided on the low refractive index layer). It is preferable to exist, and from these viewpoints, what is necessary is just to contain resin containing a perfluoro group and a polydimethylsiloxane site | part.

The coating material for forming the low refractive index layer may be adjusted by combining a binder resin forming material, a low refractive index fine particle, a photoinitiator, a solvent, and the like, which may be used in the following, or may be used by mixing and incorporating them already. . What is necessary is just to disperse | distribute according to the general adjustment method of coating liquid, in order to adjust a low refractive coating material using the following component.

As a material which forms the said low refractive index layer, you may use the well-known material which forms the low refractive index layer generally used. For example, a coating liquid containing a low refractive index inorganic fine particle such as silica or magnesium fluoride having a void and a material for forming a binder resin, or a coating liquid containing a fluorine resin or the like can be used.

As a binder resin formation material which forms the said low refractive index layer, the monomer which has a vinyl group, a (meth) acryloyl group, an epoxy group, and an oxetanyl group, these prepolymers, and the ionizing radiation curable resin of a polymer can be used. "(Meth) acryloyl group" shows a "acryloyl group" and / or a "methacryloyl group" here. Moreover, when using a thermosetting binder, you may use an inorganic binder. As an inorganic binder, a silica sol etc. are mentioned, for example. As a silica sol, the silica sol which uses a silicon alkoxide, an acidic catalyst, or an alkali catalyst as a starting material is mentioned, for example. As silicon alkoxide, tetramethoxysilane, tetraethoxysilane, etc. are used, for example.

When hardening the ionizing radiation curable resin contained in the said low refractive index layer, when performing ultraviolet irradiation, a photoinitiator is added to the coating liquid for low refractive index layers. Examples of the photopolymerization initiator include acetphenones, benzophenones, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds, thiuram compounds, and fluoro Amine compounds and the like. These can be used individually or in combination of 2 or more types. As for the usage-amount of a photoinitiator, about 1-15 mass% is preferable normally with respect to the mass of the ionizing radiation hardening type resin to be used.

As other components of the composition of the low refractive index layer, additives such as polymerization inhibitors, antioxidants, dispersants, surfactants, light stabilizers and leveling agents may be added. Moreover, as long as it is made to dry after film-forming by the wet coating method, arbitrary amount of solvent can be added.

There is no restriction | limiting in particular about the method of forming a low refractive index layer on a hard-coat layer, and can be formed by apply | coating the coating liquid containing the said material on a hard-coat layer similarly to said hard-coat layer.

Moreover, in the antireflection film of this invention, a near-infrared absorption layer can be further arrange | positioned at the other main surface side of the said transparent polyester base material. As a result, when the antireflection film of the present embodiment is disposed on the surface of the PDP, unnecessary near-infrared rays emitted when plasma discharge is caused are prevented, thereby not adversely affecting devices using peripheral electronic components, and in particular, televisions or air conditioners. This can solve the problem of causing a malfunction of the remote controller.

The material of the near-infrared absorbing layer is not particularly limited as long as it is a material having a light-transmitting property that absorbs near infrared rays. Usually, a resin in which a compound that absorbs near infrared rays is dispersed is used.

It is preferable that the said compound which absorbs near-infrared rays is a compound which has the maximum absorption wavelength in the wavelength range of 850-1100 nm. When the near-infrared absorbing layer contains the compound, it becomes possible to reduce the transmittance of the near infrared ray in the wavelength region of 850 to 1100 nm without greatly reducing the transmittance of visible light in the wavelength of 400 to 850 nm. Thereby, the antireflection film of this embodiment can be used suitably also as near-infrared absorption filters, such as PDP.

Examples of the compound having a maximum absorption wavelength in the wavelength range of 850 to 1100 nm include, for example, aluminum, azo, azine, anthraquinone, indigoide, oxadine, quinophthalonine and scarylium compounds. Organic pigments such as stilbene, triphenylmethane, naphthoquinone, dimonium, phthalocyanine, cyanine and polymethine.

As the resin for dispersing the compound that absorbs the near infrared ray, polyester resin, acrylic resin, polyurethane resin, polyvinyl chloride resin, epoxy resin, polyvinyl acetate resin, polystyrene resin, cellulose resin, polybutyral resin and the like can be used. Moreover, it can also be used as a polymer blend combining 2 or more types of these resin.

There is no restriction | limiting in particular about the method of forming a near-infrared absorption layer on a polyester base material, It can form by apply | coating the base material to the base material the coating liquid containing the said material similarly to the case of said hard-coat layer. 1-10 micrometers is preferable and, as for the thickness of a near-infrared absorption layer, 2-7 micrometers is more preferable. If the thickness is less than 1 µm, absorption of near infrared rays tends to be difficult, and if it exceeds 10 µm, cracks or curling (curvature of the film) tend to occur, so that the thickness of the near infrared absorption layer is in the above range. desirable.

It is also possible to add the compound which blocks the neon bright spectrum (orange color) of PDP suitably to a near-infrared absorption layer. As a result, red color can be more vividly colored in the PDP. As the compound which blocks the neon bright spectrum, an organic dye having a maximum absorption wavelength in the wavelength range of 580 to 620 nm can be used, and for example, cyanine, azurenium, scarylium, diphenylmethane, triphenyl Organic pigments such as methane, oxadine, azine, thiopyrium, viologen, azo, azo metal complex salts, azapolpyrine, bis azo, anthraquinone and phthalocyanine can be used.

What is necessary is just to determine suitably the thickness of a said near-infrared absorption layer, a kind of material, content rate, etc. so that the spectral transmittance of an antireflection film may be 20% or less in the whole area | region of wavelength 850-1100 nm. In addition, the main surface of the polyester base material on which the near-infrared absorbing layer is provided does not have any problem in providing a primer layer for easily gluing, and in general, it is preferable to provide a primer layer. If necessary, the main surface of the polyester base material on which the near-infrared absorbing layer is provided may be pre-adhesive surface pretreatment such as corona treatment or plasma treatment.

EMBODIMENT OF THE INVENTION Hereinafter, although this invention is demonstrated based on drawing, the description about the matter common to the matter demonstrated by the said embodiment may be abbreviate | omitted.

1 is a cross-sectional view showing an example of an antireflection film of the present invention. In FIG. 1, the antireflection film 1 is an intermediate layer such as a primer layer for easy adhesion of the polyester base 10 and the hard coat layer 11 to one main surface 10a of the polyester base 10. It is provided directly without passing through, and the low refractive index layer 12 is provided on the hard coat layer 11. The hard coat layer 11 and the low refractive index layer 12 form an antireflection layer.

2 is sectional drawing which shows another example of the antireflection film of this invention. The anti-reflective film 2 shown in FIG. 2 is except the point where the near-infrared absorption layer 14 is provided in the other main surface 10b of the polyester base material 10 via the primer layer 13, Since the part is the same as the antireflective film of FIG. 1, the same code | symbol is attached | subjected to the same part as the antireflective film of FIG. 1, and overlapping description is abbreviate | omitted.

In addition, in this invention, although the hard-coat layer needs to be provided directly on the said polyester base material without passing through the primer layer for tackifying, it is on the opposite side to the side in which the hard-coat layer of the said polyester base material is provided. On the main surface side, for example, as shown in FIG. 2, a primer layer for easy adhesion may be provided. In the present invention, "the hard coat layer is provided directly on the polyester base material" means that not only the primer layer for tackifying is provided, but other layers are also provided between the hard coat layer and the polyester base material. It means not to.

However, except that the hard coat layer is directly provided on the polyester base material, a hard coat layer and a low refractive index may be required as appropriate, such as an antistatic layer, a high refractive index layer, and an antifouling layer. It is arbitrary to provide between layers, or to install on the low refractive index layer, unless the objective of this invention is impaired. On the main surface side opposite to the side where the hard coat layer of the polyester base is provided, a suitable functional layer such as a near-infrared absorbing layer or other adhesive layer or electromagnetic wave shielding layer as shown in FIG. 2 is provided as long as the object of the present invention is not impaired. Installation on demand does not interfere.

The anti-reflection film of the present invention as described above is installed on the front surface of a plasma display panel (PDP), a liquid crystal display, or the like, which is used as a display panel of various electronic devices, for example, a large television. The main surface on the opposite side to the antireflection layer of the film is used as the display side.

Moreover, the front plate for displays of this invention consists of arrange | positioning the antireflection film of this invention as mentioned above on a board | substrate.

As the board | substrate of the front plate for displays of this invention, what is necessary is just to be optically transparent and to have sufficient intensity | strength in order to protect a display, although it does not specifically limit, For example, a glass base material, a plastic base material, etc. are used.

Although the thickness of a board | substrate also changes with the kind of display and the material of a board | substrate, it does not specifically limit, Usually, 0.2-20 mm, Preferably it is 0.2-15 mm is used.

The adhesion of the antireflection film of the present invention to the substrate may be appropriately bonded onto the substrate with an adhesive or an adhesive. Also in this case, the antireflection film of this invention is bonded by the board | substrate so that the main surface on the opposite side to this antireflection layer may become the board | substrate side of the front plate for a display.

The front panel for a display of this invention is applied to the front surface side of the display surface of a display, such as a liquid crystal display and a plastic display panel (PDP), and an antireflective function or an antireflective function depending on the kind of constituent layer of the antireflective film used, The front panel for a display which can exhibit the function as a filter which shields and near infrared rays can be provided.

(Example)

Hereinafter, although this invention is demonstrated based on an Example, this invention is not limited to a following example. In addition, "part" in an Example and a comparative example means a weight part. Volume content was calculated | required by calculation from the weight ratio of metal oxide and resin solid content, and the specific gravity literature value of each material.

(Example 1)

The antireflective film for evaluation of the same structure as the antireflective film shown in FIG. 2 was produced as follows.

A 100-micrometer-thick ultraviolet-blocking polyethylene terephthalate (PET) film (total light transmittance: 92.0% refractive index 1.66) to which a ultraviolet ray absorbent was added, having a silica-based primer layer composed of an acrylic resin on only one surface, was prepared as a polyester substrate. It was. 5.5 parts of antimony dope tin oxide fine particles (made by Mitsubishi Material, average particle diameter 20nm)

4.5 parts of zirconium oxide fine particles (Daiichi Kiggen agent, average particle diameter 10nm)

Disperbyk-180 (Dispersant made by BIC Chem Corporation) 1.0 part

Acetyl Acetone 5.0 parts

Propylene glycol monomethyl ether 30 parts

After zirconia beads having a diameter of 0.3 mm were placed in a container and dispersed for 3 hours with a paint shaker, the zirconia beads were removed to prepare a dispersion having an AT0 / ZrO ₂ weight ratio of 55:45.

To this dispersion

Pentaerythritol triacrylate part 2

Dipentaerythritol hexaacrylate 2.7parts

0.3 parts of IRGCURE907 (photopolymerization initiator made by Chiba Specialty Caucasus)

Was added to prepare a paint for hard coat layer formation (hereinafter, simply referred to as a paint for hard coat layer).

The paint for hard coat layer was apply | coated to the surface side in which the primer layer of the translucent PET film with a primer layer was not provided using the microgravure coater (made by Yasui Seiki Co., Ltd.), and it dried after that. Subsequently, the coating film was irradiated with ultraviolet rays at a dose of 500 mJ / cm 2 to cure the coating film to form a hard coat layer having a thickness of 1.5 μm (refractive index of 1.64% of the coating film with the metal oxide ratio in the coating film).

Thereafter, hollow silica fine particle dispersed ionizing radiation curable low refractive index paint (" ELCOM P-5013 " manufactured by Shokubai Kasei Co., Ltd.) was applied onto the hard coat layer described above and dried using a microgravure coater. Thereafter, the coating film was irradiated with ultraviolet rays at a dose of 800 mJ / cm 2 to cure the coating film, thereby forming a low refractive index layer having a thickness of 107 nm.

<Preparation of Paint for Near Infrared Absorption Layer>

The following materials were mixed and stirred to prepare a paint for the near infrared absorbing layer.

(1) Acrylic resin "Dial" (made by Mitsubishi Rayon): 100 parts

(2) Aromatic dimonium pigment "CIR-1085" (made by Nippon Carrit Co., Ltd.): 6 parts

(3) Cyanine-dithiol metal complex-containing site containing near infrared absorbing compound "SD50-E04N" (manufactured by Sumitomo Seika Co., Ltd., maximum absorption wavelength: 877 nm): 1 part

(4) Cyanine-dithiol metal complex portion-containing near infrared absorbing compound "SD50-E05N" (manufactured by Sumitomo Seika Co., Ltd., maximum absorption wavelength: 833 nm): 1 part

(5) Methyl ethyl ketone: 125 parts

(6) Toluene: 460 parts

Next, the near-infrared absorption layer paint was apply | coated using the said micro gravure coater on the primer layer of the said PET base material, the near-infrared absorption layer was formed so that thickness might be 4 micrometers, and the antireflection film for evaluation was produced.

(Example 2)

6 parts of antimony dope tin oxide fine particles (product made from Mitsubishi Material, average particle diameter 20nm)

4 parts of zirconium oxide fine particles (product made from Daiichi Kiggen Corporation, average particle diameter 10 nm)

 Disperbyk-180 (Dispersant made by BIC Chem Corporation) 1.0 part

Acetyl Acetone 5.0 parts

30 parts of propylene glycol monomethyl ether

And zirconia beads having a diameter of 0.3 mm were placed in a container and dispersed in a paint shaker for 3 hours, and then adjusted using a ATO / ZrO ₂ weight ratio 60:40 dispersion prepared by removing zirconia beads.

To this dispersion

Pentaerythritol triacrylate 1.7 parts

Dipentaerythritol hexaacrylate 1.6 parts

0.3 parts of IRGCURE907 (photopolymerization initiator made from Chiba Specialty Chemicals)

Was added to prepare a paint for the hard coat layer.

An antireflection film for evaluation was produced in the same manner as in Example 1 except that this paint for hard coat layer was used (a refractive index of the hard coat layer with a ratio of 36 vo1% of the metal oxide in the hard coat layer). 1.68).

(Example 3)

4.5 parts of antimony dope tin oxide fine particles (made by Mitsubishi Material, average particle diameter 20nm)

5.5 parts of zirconium oxide fine particles (Daiichi Kiggen agent, average particle diameter 10nm)

 Disperbyk-180 (Dispersant made by BIC Chem Corporation) 1.0 part

Acetyl Acetone 5.0 parts

30 parts of propylene glycol monomethyl ether

And zirconia beads having a diameter of 0.3 mm were placed in a container and dispersed in a paint shaker for 3 hours, and then adjusted using an ATO / ZrO ₂ weight ratio 45:55 dispersion prepared by removing zirconia beads.

To this dispersion

Pentaerythritol triacrylate part 3

Dipentaerythritol hexaacrylate 3part

0.5 parts of IRGCURE907 (photopolymerization initiator made from Chiba Specialty Chemicals)

Was added to prepare a paint for the hard coat layer.

Except for using the coating material for hard coat layers, the antireflection film and the near-infrared absorbing layer were formed like Example 1, and the antireflection film for evaluation was produced (refractive index of the metal oxide ratio in hard coat layer 24 vo1% hard-coat layer). 1.63).

(Example 4)

6 parts of antimony dope tin oxide fine particles (product made from Mitsubishi Material, average particle diameter 20nm)

4 parts of zirconium oxide fine particles (product made from Daiichi Kiggen Corporation, average particle diameter 10 nm)

 Disperbyk-180 (Dispersant made by BIC Chem Corporation) 1.0 part

Acetyl Acetone 5.0 parts

30 parts of propylene glycol monomethyl ether

And zirconia beads having a diameter of 0.3 mm were placed in a container and dispersed in a paint shaker for 3 hours, and then adjusted using a ATO / ZrO ₂ weight ratio 60:40 dispersion prepared by removing zirconia beads.

To this dispersion

1.9 parts pentaerythritol triacrylate

Dipentaerythritol hexaacrylate 1.9 parts

0.3 parts of IRGCURE907 (photopolymerization initiator made from Chiba Specialty Chemicals)

Was added to prepare a paint for the hard coat layer.

An antireflection film for evaluation was produced in the same manner as in Example 1 except that this paint for hard coat layer was used (a refractive index of the hard coat layer with a ratio of 31 vo1% of the metal oxide in the hard coat layer). 1.66).

(Comparative Example 1)

6.5 parts of antimony dope tin oxide fine particles (made by Mitsubishi Material, average particle diameter 20nm)

3.5 parts of zirconium oxide fine particles (Daiichi Kiggen agent, average particle diameter 10nm)

 Disperbyk-180 (Dispersant made by BIC Chem Corporation) 1.0 part

Acetyl Acetone 5.0 parts

30 parts of propylene glycol monomethyl ether

After zirconia beads having a diameter of 0.3 mm were placed in a container and dispersed for 3 hours with a paint shaker, the mixture was adjusted using an ATO / ZrO ₂ weight ratio 65:35 prepared by removing zirconia beads.

To this dispersion

Pentaerythritol triacrylate part 5

Dipentaerythritol hexaacrylate 5 parts

0.7 parts of IRGCURE907 (photopolymerization initiator made from Chiba Specialty Chemicals)

13 parts of propylene glycol monomethyl ether

Was added to prepare a paint for the hard coat layer.

An antireflection film for evaluation was produced in the same manner as in Example 1 except that this paint for hard coat layer was used (a refractive index of the hard coat layer with a ratio of 16 vo1% of the metal oxide in the hard coat layer). 1.59).

(Comparative Example 2)

As a base material, Example 1 except having used the 100-micrometer-thick ultraviolet blocking polyethylene terephthalate (PET) film (92.1% of total light transmittance) in which the primer layer (refractive index 1.58) which consists of silica containing polyester-type resin was formed on both surfaces. In the same manner as described above, an antireflection layer and a near infrared absorbing layer were formed to prepare an antireflection film for evaluation.

(Comparative Example 3)

10 parts of antimony dope tin oxide fine particles (made by Mitsubishi Material, average particle diameter 20nm)

 Disperbyk-180 (Dispersant made by BIC Chem Corporation) 1.0 part

Acetyl Acetone 5.0 parts

30 parts of propylene glycol monomethyl ether

And zirconia beads having a diameter of 0.3 mm were placed in a container and dispersed in a paint shaker for 3 hours, and then adjusted using an ATO dispersion prepared by removing zirconia beads.

To this dispersion

Pentaerythritol triacrylate 1.1 parts

Dipentaerythritol hexaacrylate 1.1part

0.15 parts of IRGCURE907 (photopolymerization initiator made from Chiba Specialty Chemicals)

Was added to prepare a paint for the hard coat layer. An antireflection film for evaluation was produced by forming an antireflection layer and a near infrared absorbing layer in the same manner as in Example 1, except that the paint for hard coat was used (refractive index of 45 vol% of the metal oxide in the hard coat layer). 1.69).

The characteristics of the antireflection films of Examples 1 to 4 and Comparative Examples 1 to 3 were evaluated as follows.

 <Refractive index>

The refractive index of the hard coat layer of each antireflection film for evaluation was measured by the refractive index measuring device "FilmTek3000" (made by SCI).

<Scratch Hardness (pencil method)>

The scratch hardness (pencil method) of the hard coat layer of each antireflection film for evaluation was measured based on JISK5600-5-4: 1999.

<Adhesiveness>

In accordance with JIS K5600-5-6: 1999, the adhesion (cross cut method) test was carried out, and the adhesion between the PET base material and the antireflection layer was evaluated (however, the rectangular pattern (checker scale) generated by the cross cut was 100). The notch to be a dog). The result is shown in Table 1, but in Table 1, (circle) and the other than that which did not have the part peeled off from 100 checkerboard scales were shown by x.

<Reflectance, visibility reflectance>

After using the spectrophotometer "Ubest V-570" (manufactured by Nihon Bunko Co., Ltd.), the luminous reflectance of the antireflective film was cut with sandpaper on the antireflective layer side and the opposite surface side, and then all were painted black with a black oily felt-tip pen. It measured using "Ubest V-570 type" (made by Nippon Bunko Corporation).

<Near-infrared transmittance>

Using the said spectrophotometer, the maximum value of the transmittance | permeability in the near-infrared wavelength region of 850-1100 nm was measured about the anti-reflective film after providing a near-infrared absorption layer as the incident light side. As a result, the near-infrared transmittance | permeability of the antireflection film for evaluation of Examples 1-4 and Comparative Examples 1-3 was all 12% or less.

<Hayes>

It measured using the Haze meta made by Nippon Denshoku Kogyo Co., Ltd ..

<Surface Resistance>

The surface resistivity value of the low refractive index layer side was measured using the surface high resistivity meter "Hyrester HT-20" (made by Mitsubishi Yuka Corporation), and using the antireflection film for evaluation after providing a near-infrared absorption layer.

Table 1 shows the measurement results excluding the near infrared transmittance.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Metal oxide (vol.%) 29 36 24 31 16 29 45 Primer layer radish radish radish radish radish U radish Haze (%) 0.4 0.7 0.4 0.4 0.3 0.4 1.7 Visibility Reflectance (%) 0.83 0.61 0.88 0.85 1.11 1.3 0.56 Maximum value (%) of difference of amplitude of reflectance in 380nm-780nm  0.19  0.14  0.31  0.08  1.05  1.64  0.25 Adhesive ○ ○ ○ ○ × ○ × Pencil hardness 2H H 2H H 2H 2H B Surface electric resistance value (Ω / □) 1 × 10 ¹⁰ 6 × 10 ⁹ 8 × 10 ¹¹ 1 × 10 ¹⁰ 2 × 10 ¹¹ 2 × 10 ¹⁰ 3 × 10 ⁸

As is apparent from Table 1, the antireflective films of Examples 1 to 4 are harder and have better adhesion than the antireflective films of Comparative Examples 1 to 3, which do not have the constituent requirements of Claim 1, and have good adhesion. It can be seen that the maximum value of the difference in the amplitudes of the reflectances between nm and 780 nm is small.

This invention can be implemented also in the form of that excepting the above in the range which does not deviate from the meaning. Embodiment disclosed in this application is an example, It is not limited to these. The scope of the present invention is interpreted in preference to the description of the appended claims over the description of the above specification, and all changes in the scope equivalent to the claims are included in the claims.

As described above, according to the present invention, the present invention can provide an antireflection film having an antireflection layer having little interference unevenness, excellent antireflection performance, and scratch resistance. By using the antireflection film or the front panel for display using the antireflection film of the present invention, it is possible to provide a front filter suitable for various displays, especially a PDP.

1 is a cross-sectional view showing an example of an antireflection film of the present invention;

It is sectional drawing which shows another example of the antireflection film of this invention.

※ Explanation of code for main part of drawing

1: Anti-reflection film 10: Polyester base material

11: hard coat layer 12: low refractive index layer

13: primer layer 14: near infrared absorption layer

Claims (6)

In the antireflection film containing a polyester base material and the antireflection layer arrange | positioned by the wet coating method in the one main surface side of the said polyester base material, The antireflection layer includes a hard coat layer and a low refractive index layer disposed above the hard coat layer from the polyester substrate side, The hard coat layer is provided directly on the polyester substrate, The hard coat layer includes a metal oxide, and the ratio of the metal oxide is 20% by volume to 42% by volume antireflection film. The method of claim 1, The said polyester base material main surface of the side which arrange | positions the said anti-reflection layer is a polyester base material which is not pre-adhesion-surface-treated, The anti-reflection film characterized by the above-mentioned. The method according to claim 1 or 2, In the board | substrate graduation peeling test which the said antireflection layer performs based on JISK5600-5-6, peeling was not confirmed from the said polyester base material, The antireflection film characterized by the above-mentioned. The method according to any one of claims 1 to 3, The maximum value of the difference of the amplitude of the reflectance in 380 nm-780 nm of the said antireflection film is 1.0% or less, The antireflection film characterized by the above-mentioned. The method according to any one of claims 1 to 4, The near-infrared absorption layer is arrange | positioned at the other main surface side of the said polyester base material, The antireflection film characterized by the above-mentioned. The antireflection film of any one of Claims 1-5 is arrange | positioned on a board | substrate, The front panel for displays characterized by the above-mentioned.

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