JPH03242601A - Antireflection article - Google Patents

Abstract

PURPOSE:To obtain an antireflection article nearly preventing the leaving of fingerprints and having superior stainproofing property by sticking particles of a specified particle size on a transparent substrate and covering the substrate with an antireflection film of an inorg. material. CONSTITUTION:Particles of 1-100 mum average particle size such as copolymerized polyester particles of 25 mum average particle size are dispersed in a freon/n- hexane mixed solvent by 0.1 wt.% and a transparent polycarbonate substrate is coated with the prepd. dispersion by means of a spin coater and heated to stick the particles on the substrate. An inorg. oxide such as ZrO2, XTiO2 or XSiO2 is then vacuum-deposited on the substrate. The resulting antireflection article has 0.6% min. surface reflectance, fingerprints are hardly left on the article because of the rough surface and superior stainproofing property and signaificat antireflection effect are obtd.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an antireflection article having excellent antifouling properties, and is suitable as a filter for display elements such as CRT1 liquid crystal displays and plasma displays. .

[Prior Art] Office automation equipment, such as word processors and displays of various computers, are equipped with filters that have an anti-reflection function in order to protect the health of operators. However, in order to provide the antireflection function, it has been necessary to layer a metal oxide or metal fluoride on the substrate using a vacuum evaporation method or a sputtering method. As a result, since the outermost layer of the filter is made of an inorganic material, there is a problem in that it is easily contaminated with dirt from hands, fingerprints, sweat, and the like.

Therefore, many proposals have been disclosed to improve this problem. For example, Japanese Patent Laid-Open No. 63-214701 discloses a method of coating the surface of an antireflection film with a hard thin film made of carbon, hydrogen, or fluorine. However, also, JP-A-1-11
Publication No. 0588 discloses a method of coating a fluorosilane thin film.

[Problems to be Solved by the Present Invention] However, even with the techniques disclosed in JP-A-1-110588 and the like, sufficient antifouling properties cannot be obtained.

The present invention attempts to eliminate the drawbacks of the prior art, and aims to provide an antireflection article with excellent antifouling properties.

[Means for Solving the Problems] In order to achieve the above object, the present invention has the following configuration.

"An antireflection article characterized by having the following A and B laminated in this order on a transparent substrate.

A, the average particle diameter is 1 μm or more and 100 μm or less,
and particles that have adhesive properties with the transparent substrate.

B. Anti-reflection coating made of inorganic material. The transparent substrate in the present invention includes, for example, inorganic glass, acrylic resin, polycarbonate, polyethylene terephthalate, vinyl chloride, polyimide, phenolic resin, diethylene glycol bisallyl carbonate polymer, polyester, polyether sulfone, poly(4-
A molded product such as methyl-1-pentene) is used, and examples of the form of the molded product include a sheet and a film.

Here, the transparent substrate has a haze value of 80 as determined by the formula below.
% or less.

Furthermore, if necessary, those colored with dyes or colored in patterns can also be used as the transparent substrate of the present invention. For example, when used as a filter for a display element, it can be used as a display body. It is useful to add color for the purpose of improving the contrast of images and preventing flicker, which is particularly seen in CRT cathode ray tubes. The color, density, etc. to be colored should be controlled according to the color tone of the display, but for example, C
In the case of green display in the RT cathode ray tube, it is preferable to color the tube in a brownish color and have a total light transmittance of 30 to 80%, particularly 40 to 70%, from the viewpoint of suitability for general users.

As for the coloring method, from the viewpoints of easy control and high productivity, it is preferable to color by source dyeing or dyeing.

The thickness of such a transparent substrate is not particularly limited, but from the viewpoint of ease of handling, shape retention, suitability for post-processing, etc. It is preferable that it is 1 to 7 millimeters,
Especially 0. 2 to 4 millimeters are preferably used.

In addition, when using a plastic substrate as a transparent substrate, it is particularly effective to coat it with a coating having hard coating properties such as polysiloxane resin, from the viewpoint of improving surface hardness and adhesion with the antireflection coating. be.

Furthermore, when coloring a transparent substrate having a hard coat film or the like, it is possible to color not only the substrate itself but also the film.

In the present invention, particles having an average particle diameter of 1 μm or more and 100 μm or less and having adhesive properties to the transparent substrate are provided on the above-mentioned transparent substrate.
The material is not particularly limited, and may be either a thermoplastic resin or a thermosetting resin as long as it has good adhesion to the transparent substrate. In particular, in order to easily carry out the adhesive treatment, thermoplastic resins are suitable, such as polyamide resins, polyester resins, ethyl cellulose, ethylene-vinyl acetate copolymers, vinyl acetate resins or derivatives thereof, polystyrene or copolymers thereof, and butyl resins. Examples include acrylic rubber made of methacrylic resin or a copolymer thereof, polyisobutylene, polypropylene, and the like. Moreover, although these can be used alone, they may be used as a mixture.

On the other hand, if stronger adhesion to the transparent substrate, durability, etc. are required, it is preferable to use a thermosetting resin. Examples of such thermosetting resins include epoxy resins and thermostable phenolic resins.

In particular, epoxy resins are preferably used because they can be applied to various transparent substrates, curing conditions can be selected from a wide range, and furthermore, they have a high degree of freedom in terms of whether they are colorless or colored. Preferred specific examples of such epoxy resins include bisphenol A type and bisphenol F type epoxy resins, and particles made of these resins in a semi-cured state are particularly preferred since they have particularly excellent adhesive properties. moreover,
It is sufficient that the main component consists of at least an epoxy resin, and spherical particles made of an epoxy resin containing a latent curing agent are most preferable. Particles containing these thermosetting resins as a component are preferably heat-cured after being applied from the viewpoint of improving adhesiveness.

In addition, the above-mentioned thermoplastic resin and thermosetting resin can be used not only individually but also in combination.
It is also possible to mix two or more types to form a single particle to further enhance ease of processing and adhesive strength. Among such particles made of two or more components, particularly preferable examples include particles made of a thermosetting resin component and an acrylic rubber component. From the viewpoint of adhesiveness, the blending ratio is preferably 30 to 95% by weight of the thermosetting resin component and 5 to 70% by weight of the rubber component, and more preferably 40% by weight of the thermosetting resin component.
A blending ratio of 10 to 60% by weight of the rubber component and 10 to 60% by weight of the rubber component is particularly preferred. Particularly excellent adhesiveness can be exhibited by setting the thermosetting component to 30% by weight or more. In addition, especially when using an epoxy resin as the thermosetting resin, the epoxy resin component is 40 to 90% by weight and the rubber component is 10% by weight.
A blending ratio of ~60% by weight is preferred. Furthermore, the epoxy resin component is 50 to 80% by weight, and the rubber component is 20 to 50% by weight.
A blending ratio of is particularly preferred from the viewpoint of adhesiveness.

Among the above-mentioned rubber components, those having an epoxy group or a glycidyl group are preferred because they can exhibit the same curing behavior as epoxy resins. Further, a rubber component having an active group capable of reacting with a thermosetting resin is also preferably used.

The various particles mentioned above are preferably dotted as uniformly as possible on a transparent substrate, but the dotting method is as follows:
Generally, a method in which particles are dispersed in a suitable dispersion medium and applied is preferably applied.

The method for dispersing and coating these particles is not particularly limited, but a method using Freon as a dispersion medium and using a spin code method, a spray coating method, etc. is preferably applied.

The average particle diameter of the particles must be 1 μm or more and 100 μm or less, and more preferably 5 μm or more and 80 μm or less. If it is less than 1 μm, a sufficient antifouling effect cannot be obtained, and if it exceeds 100 μm, transparency will be impaired and visibility will be poor. In addition, the distribution density of the particles should be determined experimentally based on the particle size and dispersion coating conditions from the viewpoint of antifouling properties and visibility. In the present invention, the particle diameter means the maximum diameter of each individual particle measured using an image analyzer, and the average particle diameter is the average of the particle diameters of at least 100 particles. .

The distribution density of such particles is given by unit area (car)
It is generally expressed in terms of the number of particles per unit, and is measured by observing with a microscope. The number of particles per unit area of the adhesive particles in the present invention is not particularly limited, but from the viewpoint of stain resistance and visibility, it is 100 to 50.
It is preferable that 000 pieces are uniformly scattered. If the number is less than 100, sufficient antifouling effect cannot be obtained;
If the number of particles exceeds 1, transparency tends to be impaired and visibility becomes worse.

Furthermore, it is also effective to subject the transparent substrate to physical or chemical surface treatment in order to further improve the adhesion between the transparent substrate and the particles.

In the present invention, an antireflection coating made of an inorganic material is provided after particles are dispersed and coated on a transparent substrate, and the components of the antireflection coating are not particularly limited, but examples include 5i02. , Sin, 2r02, ^
I2O3, Tie, TiO2, Ti2O3, Y2O3
, Yb203, MgO, Ta205, CeO2, I
f(h, 5n02, oxides such as ITO, MgF, ^
IF3, BaF2, LiF, CaF2, Na3Al
Fluorides such as F6, Na5A13F14, Si3N4
Examples include nitrides such as.

These substances can be used not only alone but also as a mixture of two or more.

Further, the antireflection coating in the present invention may be a single layer film or a multilayer film, but from the viewpoint that visibility and antireflection properties are particularly important when used as a filter for a display element, a multilayer film may be used. It is preferable to use a method that minimizes reflection. The optimum combination of film structures for such a multilayer film differs depending on the refractive index of the transparent substrate.

The optimal combination also differs depending on the required antireflection properties, other physical properties, and even durability properties. Especially regarding anti-reflection properties, many combinations have already been proposed (Optical Technology) Tact Vo.
l9. NoJ, 17-23. (197i)'0P
TIC3OF THIN FILMS' 159-2
83 A, VASICEK (NORTH-HOLLAN
D PUBLISHING COMPANY）＾MST
ERDAM (1960)), and there is no problem in using a combination of these in the present invention.

In addition, high-frequency discharge treatment is used as a means to improve adhesion between each layer.
Ion beam treatment is effective. Furthermore, low refractive index materials preferably used for the top layer of the antireflection coating include oxides such as the aforementioned 5i01 and Ahol, MgF,
, AlF3, BaF), liF, CaF+, Na5
Preferred examples include fluorides such as AIF@ and Na5^11F14.

Further, when the present invention is used as a filter for a display element, it is also possible to provide an electromagnetic wave shielding function and an antistatic function by providing a transparent conductive film on at least one layer other than the outermost layer.

The antireflection article having particles and an antireflection coating on a transparent substrate formed as described above has irregularities caused by the particles, so it is substantially free from stains caused by fingerprints, etc. Because it has an excellent antireflection effect, it is preferably used in filters for display devices.

[Example] Examples are given below, but the present invention is not limited thereto.

Example 1 (1) Dispersion coating of particles Polycarbonate (substrate thickness 2 mm) was used as a transparent substrate, and copolymerized polyester particles with an average particle size of 25 μm were coated with Freon/n-hexane (80% by weight/20% by weight) on the substrate. %) in a mixed solvent. A 1% by weight dispersion was applied using a spin coater at 300 rpm for 30 seconds. Next, the film was heated in a dryer at 120° C. for 1 hour to bond it onto the substrate.

(2) Preparation of anti-reflection coating An inorganic oxide ZrO2/Ti(h
/5i02 was coated in multiple layers using a vacuum evaporation method, with optical film thicknesses set to λ/4, λ/4, and λ/4 (λ=550 nm) in this order. The reflection interference color of the obtained antireflection article was reddish-purple, and the minimum surface reflectance was 0.6%. Further, as a stain-proofing property test, a fingerprint pressure bonding test was conducted, and the product had good stain-proofing properties, with almost no fingerprints adhering to it.

Comparative Example 1 The same procedure as in Example 1 was carried out except that particles were not provided. The reflection interference color of the obtained antireflection article was reddish-purple, and the minimal surface reflectance was 0°5%, which was the same as that of Example 1.
It also had good antireflection properties. However, in a fingerprint pressure test, fingerprints were firmly attached to the product, and it did not have stain-repellent properties.

Example 2 In Example 1, instead of the copolymerized polyester particles,
Using epoxy particles with an average particle size of 20 μm,
Example 1 except that the drying temperature of 20°C was changed to 130°C.
An antireflection article was obtained in the same manner as above. The reflective interference color of the obtained antireflection article is reddish-purple, and the minimal surface reflectance is
It was 0.6%. Furthermore, when a fingerprint pressure bonding test was carried out, it was found that almost no fingerprints were attached, and it had good antifouling properties.

[Effects of the Invention] The antireflection article obtained by the present invention has the following effects.

(1) Since the surface has an uneven shape, it has excellent antifouling properties against dirt caused by fingerprints and the like.

(2) It has an excellent antireflection effect.

Claims (1)

[Claims] (1) An antireflection article characterized in that the following A and B are laminated in this order on a transparent substrate. A, the average particle diameter is 1 μm or more and 100 μm or less,
and particles that have adhesive properties with the transparent substrate. B. Anti-reflection coating made of inorganic material.