JPH11286083A - Glare-proof film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent occurrence of an interference in a low haze and to improve a glare-proofing effect, a scratch resistance or the like by forming a hard coating layer containing particles having mean particle sizes of two specific ranges and a hard coating resin as main components on a transparent base material film. SOLUTION: A base material film is coated with a coating liquid containing at least an ionizing radiation curable resin, fine particles having a mean particle size of 1 to 500 nm for preventing an interference and particles having a mean particle size of 0.6 to 20 μm for giving a glare-proofness to form a hard coating layer, and a film for a display having a small interference on a color display and an excellent glare-proofness is obtained. To suppress an image deterioration, the smaller the particle size of the particles is, the better the image is. To obtain a sufficient glaze-proofness according to a protrusion and recess surface, it is necessary to be 0.6 μm or larger. A surface smoothness or the like is preferably 20 or less from an external appearance or more preferably 1.0 to 10 μm. As the fine particles, a mean particle size is particularly preferably 5 to 200 nm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-glare film, and more particularly to an anti-glare hard coat film suitable for a surface substrate such as a CRT or an LCD which allows a display screen to be seen through, particularly a CRT or an LCD which allows a color display screen to be seen through. The present invention relates to an antiglare hard coat film used for a surface base material such as

[0002]

2. Description of the Related Art In recent years, reflection of external light on a CRT or a flat panel display screen or reflected light generated at an interface with an air layer has become a serious problem, making it difficult to view the screen. For example, when viewing an image of a cathode ray tube, a phenomenon in which a specular reflection image of a window or a fluorescent lamp is superimposed on the image and the image becomes difficult to see is a daily experience. A method of applying a mat coating containing silica particles in order to prevent the reflection is known. However, when it is used for a color display, especially a color LCD, there is a problem that interference occurs in a dot-like manner, though it depends on the pitch of the color filters and the like. This phenomenon is more likely to occur when particles having the same particle size are used, in which the haze is low, that is, the particle density is low. For this reason, conventionally, the density of the particles has been increased at the expense of transparency to suppress the occurrence of interference. This caused the haze to rise and the screen to be very unsightly.

[0003]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a film for an anti-glare display which has a low haze, prevents the occurrence of interference, is excellent in anti-glare effect, scratch resistance, transparency and suppresses image quality deterioration. Is what you do.

[0004]

According to the present invention, there are provided a transparent substrate film (1) comprising: particles (2) having an average particle size of 0.6 to 20 μm; and fine particles (3) having an average particle size of 1 to 500 nm. An anti-glare film comprising a hard coat layer (5) containing a hard coat resin (4) as a main component, wherein the particles (2) are added to the hard coat resin (4) in an amount of 0. The antiglare film, wherein the content of the fine particles (3) is 0.001 to 80% by weight based on the hard coat resin (4), and the haze is 30% or less. An antiglare film, wherein said fine particles (3)
Is colloidal silica.

[0005] Further, the above-mentioned antiglare film in which another hard coat layer (6) is provided between the transparent base film (1) and the hard coat layer (5). Average particle size 1-500n to prevent interference with ionizing radiation-curable resin
m and an average particle diameter of 0.6-20 μm for imparting antiglare properties
A coating liquid containing particles of m is coated to form a hard coat layer to obtain a display film having little interference on a color display and excellent antiglare properties.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The transparent substrate film (1) used in the present invention is not particularly limited, but it is preferable to use a film having high transparency in consideration of workability and application. Cellulose-based resins such as cellulose acetate and acetate, polyethylene terephthalate,
Polyester resin such as polyethylene naphthalate,
It is preferable to use an artificial resin film such as an acrylic resin such as polymethyl methacrylate or a polycarbonate resin. Further, a resin layer (7) for improving the adhesion between the substrate and the hard coat layer (5) may be formed on the substrate.

The particle size of the particles (2) used for imparting the antiglare property in the present invention is preferably as small as possible in order to suppress the image deterioration, but is not preferable in order to obtain a sufficient antiglare property due to the unevenness of the surface. 0.6 μm or more, and preferably 20 μm or less, and more preferably 1.0 μm or less, in terms of surface smoothness and the like.
It is not less than μm and not more than 10 μm.

The particles (2) used in the present invention include, but are not particularly limited to, silica, silicone resin particles, acrylic resin particles, styrene resin particles, nylon resin particles, and the like. In order to diffuse light, a sphere or a sphere is preferred. The reflection of light, which is a problem, mostly occurs at the interface between the air and the particles and at the interface between the particles and the hard coat resin. The former reflection is caused by a difference in refractive index between air and particles, and the latter reflection is caused by a difference in refractive index between particles and a hard coat resin. If the refractive index of the particles is too large, the transparency is significantly impaired, and the image quality is also deteriorated. If the difference in refractive index between the hard coat resin and the particles is small, diffuse reflection at the interface between the particles and the hard coat resin cannot be used, and antiglare properties cannot be obtained for the haze. If the difference between the refractive indices is too large, the transmittance will decrease. Therefore, by appropriately selecting the refractive index of the particles and the refractive index of the hard coat resin, the transparency and the antiglare property can be effectively exhibited.

In the present invention, the thickness of the hard coat layer (5) containing the particles (2) and the like is not more than the particle diameter of the particles (2), preferably 80% of the average particle diameter of the particles (2).
It is as follows. If the hard coat layer (5) is thicker than 80% of the average particle diameter, most of the particles (2) will be hard depending on the particle size distribution of the particles (2) and the refractive index difference from the hard coat resin (4). It is buried in the coat layer (5), and sufficient antiglare property cannot be obtained. Further, in order to prevent the loss of the particles, the average particle diameter is desirably 50% or more. When such conditions are satisfied, the anti-glare (for display) film of the present invention, which is low in haze, prevents interference, has excellent anti-glare effect, scratch resistance, transparency and suppresses image quality deterioration, can be obtained. However, when the above conditions are satisfied, the hardness of the hard coat layer (5) may become insufficient, and the hardness of the hard coat layer (5) may be lower than that of the hard coat layer (5), that is, the transparent substrate film (1).
By forming another hard coat layer (6) on the hard coat layer (6) and providing the hard coat layer (5) on the hard coat layer (6), it is possible to solve the case where the hardness becomes insufficient. The hard coat layer (6) may be the same as the hard coat layer (5), but may not contain the particles (2) and the fine particles (3) in view of the above-mentioned purpose. The hard coat resin (8) may be different from the resin (4) used for the above. The thickness of the hard coat layer (6) is not particularly limited.
It is preferably from 10 μm to 10 μm.

As the fine particles (3) used for preventing interference in the present invention, fine particles having an average particle size of 1 to 500 nm are used, and fine particles having an average particle size of 5 to 200 nm are particularly preferably used. If the average particle size exceeds 500 nm, the transmittance tends to be impaired. If the average particle size is less than 1 nm, the effect of preventing interference becomes extremely small.

The fine particles (3) are preferably colloidally dispersed inorganic oxide fine particles. Examples of the inorganic oxide fine particles include silicon oxide, antimony oxide, tin oxide, indium oxide, zinc oxide, alumina, titania, zirconia and the like. Among them, silicon oxide, for example, colloidal silica is preferable in consideration of price and color. As these fine particles (3), it is more preferable to mix a hard coat resin with fine particles (3) which have been treated with acryloxy-functional silane or the like and modified with acrylate so as to be crosslinked by ionizing radiation. Since the surface acrylated inorganic oxide fine particles participate in the crosslinking with the hard coat resin, even if they are blended in a large amount, the hardness does not decrease and the hardness tends to increase. In addition, mixing is easy without the need for a step of dispersing in a hard coat resin, and excellent in permeability after mixing. Acrylate-treated inorganic oxide fine particles may be used in combination with acrylate-free surface-treated fine particles.

According to the present invention, as described above, the particles (2) and the fine particles (3) are contained in the hard coat layer (5), so that the density of the particles is increased and the occurrence of interference is suppressed while sacrificing the transparency. Solves the problems of the prior art, which suppresses the occurrence of interference and provides an antiglare film having a haze of 30% or less. It is. In the present invention, the occurrence of interference is sufficiently suppressed and the haze is 20% or less,
% Or less of an antiglare film.

The amount of the particles (2) imparting antiglare properties is
Although it is affected by the specific gravity of the particles (2) used, it is usually in the range of 0.05 to 30% by weight, preferably 0.2 to 5% by weight of the solid content of the resin (4). The added amount of the fine particles (3) for preventing interference is 0.001 to 0.001 of the solid content of the resin (4).
80% by weight, preferably in the range of 0.2-40% by weight. When an antireflection layer (9) having a lower refractive index is further formed on the hard coat layer (5), the higher the refractive index of the hard coat layer is, the higher the antireflection effect is. Therefore, antimony oxide, tin oxide, zirconia If fine particles having a refractive index higher than that of the hard coat resin (4) are used, the refractive index of the hard coat layer (5) is increased and the effect of preventing reflection is enhanced.

As the hard coat resin (4) for forming the hard coat layer (5) used in the present invention, a thermosetting resin or an ionizing radiation curable resin can be mainly considered. In view of this, it is preferable to use an ionizing radiation-curable resin. The ionizing radiation-curable resin is formed from a paint containing at least a resin that is cured by irradiation with an electron beam or ultraviolet rays. In particular,
It contains a photopolymerizable prepolymer, a photopolymerizable monomer, and a photopolymerization initiator, and further contains, if necessary, additives such as a sensitizer, a non-reactive resin, and a leveling agent, and a solvent. The structure and molecular weight of the photopolymerizable prepolymer relate to the curing of the ionizing radiation-type curable coating material, and determine properties such as hardness and crack resistance. The photopolymerizable polymer generally undergoes radical polymerization when an acryloyl group introduced into the skeleton is irradiated with ionizing radiation. Those cured by radical polymerization are particularly preferred because they have a high curing rate and a high degree of freedom in resin design. As the photopolymerizable prepolymer, an acrylic prepolymer having an acryloyl group is particularly preferable, and an acrylic prepolymer having two or more acryloyl groups in one molecule and having a three-dimensional network structure is preferable. As the acrylic prepolymer, urethane acrylate, melamine acrylate, polyester acrylate, and the like can be used. The photopolymerizable monomer is
It is used for diluting a high-viscosity photopolymerizable prepolymer, lowering the viscosity and improving workability, and as a crosslinking agent for imparting coating strength. Further, the coating film becomes harder than necessary when the mixing amount of the photopolymerizable monomer increases, so that the mixing ratio is preferably selected so as to obtain a desired hardness or a desired flexibility. Also, the hard coat layer (6) can be appropriately selected from the above description and used within a range that does not impair the above-mentioned purpose.

For example, when used for bending the anti-glare film of the present invention, the film has excellent flexibility, thermosetting properties,
The hardness can be adjusted by mixing a non-reactive resin such as a thermoplastic acrylic resin or an epoxy resin.
Incidentally, the hard coat layer referred to in the present invention has a pencil hardness of H or more. As a method for forming the hard coat layer using the ionizing radiation paint, a usual coating method, for example, bar, blade, spin, gravure, spray or the like can be used.

[0016]

EXAMPLES The present invention will be described in more detail with reference to the following examples. ** Example 1 DPHA on a 188 μm-thick polyester film.
(Hexafunctional acrylate monomer) 50 parts, bifunctional urethane acrylate 41 parts, photoinitiator 3 parts, average particle size 5 μm
3 parts of silica particles, 3 parts of colloidal silica fine particles having an average particle diameter of 10 nm (10 parts of a 30% by weight dispersion), and 1 part of toluene
00 parts of the coating material was applied with a Mayer bar so that the hardened resin binder portion had a cured thickness of 3.5 μm, dried with a solvent, and irradiated with ultraviolet rays with a high-pressure mercury lamp for 30 minutes.
It was irradiated with 0 mJ / cm2 and cured.

** Comparative Example 1 DPHA on a 188 μm thick polyester film
(Hexafunctional acrylate monomer) 50 parts, bifunctional urethane acrylate 41 parts, photoinitiator 3 parts, average particle size 5 μm
A hard coat resin binder portion having a cured thickness of 3.5 was prepared by coating a coating composed of 3 parts of silica particles and 100 parts of toluene.
It was applied with a Mayer bar so as to have a thickness of μm, and after drying the solvent, it was cured by irradiating 300 mJ / cm 2 of ultraviolet rays with a high-pressure mercury lamp.

** Comparative Example 2 DPHA on a 188 μm thick polyester film
(Hexafunctional acrylate monomer) 50 parts, bifunctional urethane acrylate 41 parts, photoinitiator 3 parts, average particle size 5 μm
The hard coat resin binder portion of the coating composition comprising 12 parts of silica particles and 100 parts of toluene has a thickness of 3.
It was applied with a Mayer bar so as to have a thickness of 5 μm, and after drying the solvent, it was cured by irradiating 300 mJ / cm 2 of ultraviolet rays with a high pressure mercury lamp.

The antiglare display films obtained in Example 1 and Comparative Examples 1 and 2 were evaluated as follows. The results are described below. (1) Transmittance Spectrophotometer UV-310, manufactured by Shimadzu Corporation
The transmittance at 550 nm was measured using 0PC. (2) Haze The haze was measured using a haze meter manufactured by Nippon Denshoku Industries. (3) Interference A film was pasted on a TFT liquid crystal color display having a pitch of 360 μm for RGB, and the degree of interference was visually evaluated. A: No interference B: Strong interference (4) Image sharpness A film was stuck on a transmissive liquid crystal display, and the image sharpness was visually judged. A: Very sharp B: Lack of sharpness

<< Evaluation Results >> Transmittance (%) Haze (%) Interference Clarity of Image Example 1 85% 5.0% A A Comparative Example 1 85% 4.8% B A Comparative Example 2 45% 40. 0% AB

[0021]

The base film of the present invention has an average particle size of 1 to 50 for preventing interference with at least the ionizing radiation-curable resin.
0 nm fine particles and an average particle size of 0.6 to 2 for imparting antiglare properties
The antiglare film having a hard coat layer formed by coating a coating liquid containing particles having a particle size of 0 μm is useful as a display film having little interference on a color display and having excellent antiglare properties.

Claims (5)

[Claims] 1. A transparent base film (1) having particles (2) having an average particle size of 0.6 to 20 μm and an average particle size of 1 to 500 n
An anti-glare film comprising a hard coat layer (5) mainly composed of m fine particles (3) and a hard coat resin (4). 2. A method according to claim 1, wherein said particles (2) are hard coat resins (4).
0.05 to 30% by weight, and the fine particles (3) are 0.001 to 80% by weight based on the hard coat resin (4).
The anti-glare film according to claim 1, wherein the content is 3. The antiglare film according to claim 1, wherein the haze is 30% or less. 4. The antiglare film according to claim 1, wherein said fine particles (3) are colloidal silica. 5. The anti-glare film according to claim 1, wherein another hard coat layer (6) is provided between the transparent substrate film (1) and the hard coat layer (5).