JP2009128609A - Antireflection laminate and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antireflection laminate, having improved scratch resistance in addition to sufficient anti-reflection performance and anti-staining properties and a method of manufacturing the same. <P>SOLUTION: The antireflection laminate includes a transparent base material and a low-refractive index layer formed on one surface of the transparent base material and containing zeolite, wherein the particle diameter of the zeolite is 5 to 200 nm, crystallinity of zeolite is ≥0.64, the content of the zeolite is 5 to 95%, and the refractive index of the low refractive index layer is 1.20 to 1.40. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an antireflection laminate and a manufacturing method thereof, and more particularly, to an antireflection laminate used on the surface of a display device such as a liquid crystal display, a CRT display, a projection display, a plasma display, and an EL display, and a manufacturing method thereof.

  In general, a display is used in an environment where external light or the like enters regardless of whether the display is used indoors or outdoors. Incident light such as external light is specularly reflected on the display surface and the like, and the reflected image thereby mixes with the display image, thereby degrading the screen display quality. Therefore, it is essential to provide an antireflection function to the display surface or the like.

  In the antireflection laminate used on the outermost surface of the liquid crystal display, a technique for developing an antireflection function by providing a low refractive index layer on the outermost surface has been proposed.

  Since air is a substance having a lower refractive index than other substances, a method of forming a low refractive index layer by dispersing inorganic fine particles, porous or hollow silica sol having voids inside in a binder matrix has been proposed. . (See Patent Document 1 and Patent Document 2)

  At this time, in the obtained low refractive index layer, a large amount of hollow silica is present on the surface. Since the hollow silica shell is amorphous, there is a drawback that sufficient scratch resistance cannot be obtained.

In order to overcome this drawback, a silica zeolite thin film made of a partially crystallized zeolite precursor has been proposed (see Patent Document 3). By using a partially crystallized zeolite precursor having internal voids, the hardness increased and the scratch resistance improved. However, the internal voids are not sufficient when using precursors. In order to obtain sufficient low reflection performance, a process of bringing the cured thin film into contact with an extraction solvent and removing the organic polymer to make it porous is also necessary. Further, since it is not a perfect crystal, there are a large amount of amorphous parts, and the scratch resistance is not sufficient.
JP 7-133105 A JP 2001-233611 A JP 2004-37795 A

  The present invention has been made in view of the above problems, and an object thereof is to provide an antireflection laminate having improved anti-scratch properties while having sufficient antireflection performance and antifouling properties, and a method for producing the same. .

  The invention according to claim 1 of the present invention is an antireflection laminate including a transparent base material and a low refractive index layer containing zeolite formed on one side of the transparent base material.

  The invention according to claim 2 of the present invention is the antireflection laminate according to claim 1, wherein the zeolite has a particle size of 5 nm or more and 200 nm or less.

  The invention according to claim 3 of the present invention is the antireflection laminate according to claim 1 or 2, wherein the zeolite has a crystallinity of 0.64 or more.

  The invention according to claim 4 of the present invention is the antireflection laminate according to any one of claims 1 to 3, wherein the zeolite content is 5% or more and 95% or less. is there.

  The invention according to claim 5 of the present invention is characterized in that the refractive index of the low refractive index layer is 1.20 or more and 1.40 or less, and the antireflection laminate according to any one of claims 1 to 4 It is a body.

  The invention according to claim 6 of the present invention is a method for producing an antireflection laminate, comprising preparing a transparent substrate and forming a low refractive index layer containing zeolite on one side of the transparent substrate. is there.

  The invention according to claim 7 of the present invention is the method for producing an antireflection laminate according to claim 6, wherein the zeolite has a particle size of 5 nm or more and 200 nm or less.

  The invention according to claim 8 of the present invention is the method for producing an antireflection laminate according to claim 7 or 8, wherein the crystallinity of the zeolite is 0.64 or more. .

  The invention according to claim 9 of the present invention is the method for producing an antireflection laminate according to any one of claims 6 to 8, characterized in that the zeolite content is 5% or more and 95% or less. It is what.

  The invention according to claim 10 of the present invention is characterized in that the refractive index of the low refractive index layer is 1.20 or more and 1.40 or less, and the antireflection laminate according to any one of claims 6 to 9. This is a method for manufacturing a body.

  According to the present invention, it is possible to provide an antireflection laminate having improved anti-scratch properties while having sufficient antireflection performance and antifouling properties, and a method for producing the same.

  Hereinafter, embodiments of the present invention will be described in detail.

  The antireflection laminate according to the embodiment of the present invention is characterized in that the low refractive index layer contains zeolite. By including crystalline zeolite having internal voids in the low refractive layer, both low reflectance and improved scratch resistance can be achieved. Hereinafter, a mode in which the outermost surface layer is a low refractive index layer will be described.

  As the transparent substrate of the present invention, a film or sheet made of various organic polymers can be used. For example, a base material usually used for an optical member such as a display can be cited. In consideration of optical properties such as transparency and refractive index of light, and various physical properties such as impact resistance, heat resistance and durability, polyethylene is used. Polyolefins such as polypropylene, polyesters such as polyethylene terephthalate and polyethylene naphthalate, celluloses such as triacetyl cellulose, diacetyl cellulose and cellophane, polyamides such as 6-nylon, acrylics such as polymethyl methacrylate, polystyrene, poly Those made of an organic polymer such as vinyl chloride, polyimide, polyvinyl alcohol, polycarbonate, ethylene vinyl alcohol are used. In particular, polyethylene terephthalate, triacetyl cellulose, polycarbonate, and polymethyl methacrylate are preferable.

  Furthermore, functions are added to these organic polymers by adding known additives such as antistatic agents, ultraviolet absorbers, infrared absorbers, plasticizers, lubricants, colorants, antioxidants, flame retardants, etc. You can also use it. Further, the transparent substrate is not made of one or a mixture of two or more selected from the above organic polymers, or a polymer, and may be a laminate of a plurality of layers.

  A hard coat layer may be laminated on the transparent substrate of the present invention. When laminating the hard coat layer, an ultraviolet curable resin such as polyfunctional urethane acrylate and a photopolymerization initiator that improves the curability such as 1-hydroxycyclohexyl phenyl ketone can be used.

  The low refractive index layer formed on one side of the transparent substrate according to the embodiment of the present invention preferably has a form mainly composed of zeolite and a suitably selected transparent resin binder.

  Although it does not restrict | limit especially as a transparent binder, The curable resin and thermosetting resin by ionizing radiation and ultraviolet irradiation can be used, and especially acrylic acid esters, acrylamides, and methacrylic acid esters which are ultraviolet curable. Acrylic resins such as methacrylamides, organic silicon resins, and thermosetting polysiloxane resins are preferred.

  The zeolite fine particles according to the embodiment of the present invention preferably have an average particle diameter in the range of 5 nm to 200 nm. If the average particle diameter is in the range of 5 nm or more and 200 nm or less, it is possible to achieve both reduction of the refractive index and no loss of transparency. When this average particle diameter is larger than 200 nm, light is scattered on the surface of the low refractive index layer, and it looks whitish and transparency is lowered. If the average particle size is less than 5 nm, the fine particles tend to aggregate.

  The crystallinity of the zeolite according to the embodiment of the present invention is preferably 0.64 or more. By setting the crystallinity to 0.64 or more, both the hardness of the zeolite particles and the internal voids can be achieved. When the degree of crystallinity is less than 0.64, a considerable amorphous portion is not crystallized, and voids of zeolite fine particles are reduced. In addition, the hardness of the film decreases. The crystallinity of zeolite can be determined by infrared spectroscopy. Furthermore, the crystallinity of zeolite is preferably 0.80 or more.

  When the amount of the zeolite according to the embodiment of the present invention is 5% by mass to 95% by mass in the low refractive index layer, a low reflection effect is obtained and the lower layer (for example, a hard coat layer) is added. Adhesion is improved. If the zeolite content is 5% or less, a sufficient low reflection effect cannot be obtained. Moreover, when the content rate of a zeolite becomes 95% or more, adhesiveness with a lower layer (for example, hard coat layer) will be impaired.

  When the refractive index of the low refractive index layer according to the embodiment of the present invention is 1.20 or more and 1.40 or less, antireflection performance is obtained, and scratch resistance is improved. When the refractive index is greater than 1.40, sufficient antireflection performance cannot be obtained. When the refractive index is less than 1.20, the voids in the low refractive index layer increase, and the scratch resistance decreases. Furthermore, the thickness of the low refractive index layer is preferably 80 nm or more and 120 nm or less.

Since the antireflection laminate of the present invention is usually used by being mounted on the outermost layer of a display device such as an LCD display, it is desirable to have antifouling properties. Therefore, it is preferable to contain an Rf— (CH ₂ ) n —Si—O bond. By adding fluorine silane over the low refractive index layer, an Rf— (CH ₂ ) n —Si—O bond can be contained. By making the molar ratio of silicon alkoxide and fluorine silane 1.0 / 0.01 to 1.0 / 0.2, both low refractive index and strength can be achieved, and antifouling performance can be exhibited. Is preferred.

  Further, the antireflection laminate of the present invention is required to have conductivity from the viewpoint of preventing dust adhesion due to charging during processing and use. In order to realize this, it is preferable to provide a high refractive index layer having conductivity under the low refractive index layer.

  The material for forming the high refractive index layer is selected from conductive materials, such as indium oxide, tin oxide, indium oxide-tin oxide (ITO), zinc oxide, zinc oxide-aluminum oxide (AZO), zinc oxide- One kind or a mixture of two or more kinds selected from gallium oxide (GZO) and indium oxide-cerium oxide can be used.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, the technical scope of this invention is not limited to these Examples.

[Preparation of hard coat layer]
80 parts by mass of a polyfunctional urethane acrylate having a trade name “UV1700B” manufactured by Nippon Synthetic Chemical Co., Ltd. Were mixed in methyl isobutyl ketone to prepare a coating solution for forming a hard coat layer.

[Synthesis of zeolite A]
Sodium hydroxide, sodium aluminate, pure water, and silica were mixed at a molar ratio of 5.5 Na ₂ O: 1.0 Al ₂ O ₃ : 4.0 SiO ₂ : 190 H ₂ O. The mixture was reacted by shaking at 60 ° C. for 4 days to obtain zeolite A. Zeolite A was treated with a centrifugal separator for 0.5 hours to remove precipitated particles, and then zeolite A having a particle size of 100 nm or less was obtained. The crystallinity was 0.97.

[Synthesis of zeolite B]
In the same manner as in the synthesis of zeolite A, sodium hydroxide, sodium aluminate, pure water, and silica were mixed. The mixture was vibrated at 60 ° C. for 1 day to obtain zeolite B. Zeolite B was treated with a centrifuge for 0.5 hour to remove the precipitated particles, and then zeolite B having a particle size of 100 nm or less was obtained. The crystallinity was 0.57.

[Preparation of coating liquid A for low refractive index layer]
0.015 mol of tridecaftiltrimethoxysilane was added to 1 mol of the tetramitoxysilane solution to prepare a mixed solution. A matrix prepared by adding 7.5 mol of 1N sodium hydroxide to 1 mol of the mixed solution and zeolite A were combined in a ratio of 60 parts by weight and 40 parts by weight, so that the solid content was 15%. Isopropyl alcohol was added and the mixture was stirred and hydrolyzed for 1 hour, and then isopropyl alcohol was added to prepare a 4 wt% low refractive index layer coating solution.

[Preparation of coating liquid B for low refractive index layer]
0.015 mol of tridecaftiltrimethoxysilane was added to 1 mol of the tetramitoxysilane solution to prepare a mixed solution. A matrix prepared by adding 7.5 mol of 1N sodium hydroxide to 1 mol of the mixed solution and zeolite B were combined in a ratio of 60 parts by weight and 40 parts by weight, and isopropyl was prepared so that the solid content was 15%. After adding alcohol and stirring and hydrolyzing for 1 hour, isopropyl alcohol was added to prepare a 4 wt% low refractive index layer coating solution.

[Preparation of coating liquid C for low refractive index layer]
0.015 mol of tridecaftiltrimethoxysilane was added to 1 mol of the tetramitoxysilane solution to prepare a mixed solution. A matrix prepared by adding 7.5 mol of 1N hydrochloric acid to 1 mol of the mixed solution and a silica sol having voids in the interior were prepared so as to have a ratio of 60 parts by weight and 40 parts by weight, and the solid content was 15%. Isopropyl alcohol was added and the mixture was stirred and hydrolyzed for 1 hour, and then isopropyl alcohol was added to prepare a 4 wt% low refractive index layer coating solution.

[Example 1]
(Formation of hard coat layer)
The prepared coating liquid for forming the hard coat layer was applied to a triacetyl cellulose film (transparent substrate) with a film thickness of 5 μm by a microgravure method and irradiated with a 120 W metal halide lamp from a distance of 20 cm for 10 seconds. A coat layer was formed.

[surface treatment]
The laminate of the hard coat layer formed on the triacetyl cellulose (TAC) film (transparent substrate) was immersed in a 1.5N NaOH aqueous solution heated to 50 ° C. for 2 minutes for alkali treatment, washed with water, and then washed with 0.0. It was neutralized by immersing in a 5 wt% -H ₂ SO ₄ aqueous solution at room temperature for 30 seconds, followed by washing with water and drying.

[Preparation of low refractive index layer]
The coating liquid A for low refractive index layer is applied by a micro gravure method and heated and cured in a 120 ° C. oven for 5 minutes to form a low refractive index layer having a thickness of 100 nm on the hard coat layer, thereby obtaining an antireflection laminate. It was.

[Comparative Example 1]
In the same manner as in Example 1, a hard coat layer having a layer thickness of 5 μm was formed on a triacetyl cellulose (TAC) film (transparent substrate) using a coating liquid for forming a hard coat layer. Further, the surface treatment of the hard coat layer was performed in the same manner as in Example 1.

  Next, the coating liquid B for low refractive index layer is applied by a micro gravure method and cured by heating in a 120 ° C. oven for 5 minutes to form a low refractive index layer having a thickness of 100 nm on the hard coat layer, and an antireflection laminate. Got the body.

[Comparative Example 2]
In the same manner as in Example 1, a hard coat layer having a layer thickness of 5 μm was formed on a triacetyl cellulose (TAC) film (transparent substrate) using a coating liquid for forming a hard coat layer. Further, the surface treatment of the hard coat layer was performed in the same manner as in Example 1.

  Next, the coating solution C for low refractive index layer was applied by a micro gravure method and heated and cured in a 120 ° C. oven for 5 minutes to form a low refractive index layer having a thickness of 100 nm on the hard coat layer. Thus, an antireflection laminate was obtained.

  In Example 1 and Comparative Examples 1 and 2, various physical property evaluation methods are shown below.

(1) Optical characteristic reflectance: The reflectance at 550 nm was measured at an incident angle of 5 with a spectrophotometer.
Haze: Calculated according to the haze test method of JIS-K7105.

(2) Adhesive paint general test method Evaluation was made by the number of remaining coating films according to the cross-cut adhesion test method of JIS-K5400.

(3) Scratch resistance test Using steel wool # 0000, a five-way scratch test was performed with a load of 300 g / cm ² to inspect the appearance of the scratches by visual inspection. The evaluation was made in four stages: no damage (◎), light scratch (◯), considerable damage (△), and significant damage (x).

(4) Water contact angle A water drop was placed on the surface of the coating, and the contact angle between the water drop and the surface was measured. For the measurement, a contact angle meter manufactured by Kyowa Interface Science Co., Ltd. was used.

(5) Fingerprint wiping property A fingerprint was adhered to the surface of the coating, and the wiping property was visually inspected with a tissue paper. The evaluation was made in three stages: easy wiping (◯), wiping (Δ), and non-wiping (×).

  As shown in Table 1, both Example 1 and Comparative Example 2 had low reflectivity, and the desired low refractive index layer could be obtained. However, the antireflection laminate obtained in Example 1 was adhesive. Excellent in hardness, scratch resistance and antifouling property. On the other hand, it can be seen that the antireflection laminate of Comparative Example 2 has significantly inferior properties in terms of scratch resistance strength. Further, comparing the antireflection laminate obtained in Comparative Example 1 and the antireflection laminate obtained in Example 1, the antireflection laminate of Example 1 is superior in both scratch resistance and reflectance. I understand that

  The antireflective laminate of the present invention can form a film having both the optical characteristics of a low refractive index and excellent physical strength by adding it to zeolite in the low refractive index layer. That is, the antireflection laminate of the present invention is disposed in the outermost layer of a display or the like, can sufficiently withstand harsh environments and handling, and has excellent antifouling properties.

Claims (10)

A transparent substrate;
An antireflection laminate comprising a low refractive index layer containing zeolite formed on one side of the transparent substrate.   The antireflective laminate according to claim 1, wherein the zeolite has a particle size of 5 nm to 200 nm.   The antireflective laminate according to claim 1 or 2, wherein the zeolite has a crystallinity of 0.64 or more.   The antireflection laminate according to any one of claims 1 to 3, wherein the content of the zeolite is 5% or more and 95% or less.   The antireflection laminate according to any one of claims 1 to 4, wherein the low refractive index layer has a refractive index of 1.20 or more and 1.40 or less. Prepare a transparent substrate,
A method for producing an antireflection laminate, wherein a low refractive index layer containing zeolite is formed on one side of the transparent substrate.   The method for producing an antireflection laminate according to claim 6, wherein the zeolite has a particle size of 5 nm to 200 nm.   The method for producing an antireflection laminate according to claim 7 or 8, wherein the zeolite has a crystallinity of 0.64 or more.   The method for producing an antireflection laminate according to any one of claims 6 to 8, wherein the content of the zeolite is 5% or more and 95% or less.   The method for producing an antireflection laminate according to any one of claims 6 to 9, wherein a refractive index of the low refractive index layer is 1.20 or more and 1.40 or less.