JP4567124B2 - Touch panel - Google Patents

Description

【００３５】
【表２】

【００３６】
以上のようにして得られた透明ハードコートフィルムの視認性（透明性、グレア防止性、ＲＧＢぎらつき防止性）について評価した結果を表３に示す。透明性、グレア防止性、ＲＧＢぎらつき防止性の評価は以下のように行った。
【００３７】
［透明性］
ＳＭカラーコンピューターＨＧＭ−２Ｋ（スガ試験機社）を用いてヘーズ値「％」（ＪＩＳ−Ｋ７１０５）を測定すると共に、画像を表示させたＣＲＴ画面上に透明ハードコートフィルムを積層した場合に表示画像がぼけるかどうかについて目視評価した。目視評価した結果で良かったものを「○」、悪かったものを「×」とした。
【００３８】
［グレア防止性］
ＳＭカラーコンピューターＵＧＶ−５Ｋ（スガ試験機社）を用いて光沢度「％」（ＪＩＳ−Ｋ５４００）を測定すると共に、画像を表示させたＣＲＴ画面上に透明ハードコートフィルムを積層した場合に外部光の映り込みによって表示画像が見にくくなるかどうかについて目視評価した。目視評価した結果で良かったものを「○」、悪かったものを「×」とした。
【００３９】
［ＲＧＢぎらつき防止性］
カラー画像を表示させたＣＲＴ画面上に透明ハードコートフィルムを積層した場合に、カラー表示のＲＧＢ発光点が拡大強調されて、特に表示画面の白色部分がぎらついて見えるかどうかについて目視評価した。目視評価した結果で良かったものを「○」、悪かったものを「×」とした。
【００４０】
［視認性］
総合評価として、透明性、グレア防止性、ＲＧＢぎらつき防止性の三評価全て良かったものを「○」、三評価の内の何れか一つの評価でも悪かったものを「×」とした。
【００４１】
【表３】

【００４２】
表３の結果からも明らかなように、実施例１〜３の透明ハードコートフィルム１は、透明性、グレア防止性、ＲＧＢぎらつき防止性の全てに優れた視認性を得られていた。
【００４３】
一方、比較例１及び３の透明ハードコートフィルムは、光沢度が低く抑えられているためにグレア防止性は備えているが、透明ハードコート層に無機質粒子として比較的大きな粒径のものが１種類しか含まれていないために、ＲＧＢの発光点による画面のぎらつきを抑えることができず、非常に視認性に劣るものであった。特に、比較例３の透明ハードコートフィルムは、ヘーズ値も高く、透明性の点でも劣るものであった。
【００４４】
また、比較例２及び４の透明ハードコートフィルムは、透明ハードコート層に無機質粒子として比較的小さな粒径のものが１種類しか含まれていないために、ヘーズ値は低くて透明性には優れているが、光沢度が高くてグレア防止性が極めて低く、非常に視認性に劣るものであった。尚、透明ハードコート層に無機質粒子として比較的大きな粒径のものが含まれていないために、光沢度が低くならなかった反面、表面凹凸も生じなかったために、レンズ効果によるＲＧＢの発光点による画面のぎらつきも生じることがなかった。
【００４５】
また、比較例５の透明ハードコートフィルムは、電離放射線硬化型樹脂ではなく熱硬化性樹脂を使用しているために、無機質粒子の添加量を電離放射線硬化型樹脂（実施例１）の場合と等しくして透明性を維持しても、電離放射線硬化型樹脂に粒状物を混合させた場合に特有に生じる波状凹凸が生じず、光沢度が高くなってグレア防止性を得ることができず、ＲＧＢぎらつき防止性も得られないために、非常に視認性に劣るものであった。
【００４６】
【発明の効果】
本発明のタッチパネルは、タッチパネルの表面基材を透明高分子フィルム上に少なくとも電離放射線硬化型樹脂及び２以上の異なる平均粒径の無機質粒子から構成される透明ハードコート層を設けたものとすることにより、高精細化されたカラーディスプレイ表面上に使用してもカラー画面がぎらついて見えるようなことがなく、且つ外部光に対するグレアを防止しつつ、透明性が低下して画像表示がぼけることのない、ディスプレイの視認性に極めて優れたタッチパネルを得ることができるようになる。
【図面の簡単な説明】
【図１】 本発明の透明ハードコートフィルムの一実施例を示す断面図。
【符号の説明】
１・・・透明ハードコートフィルム
２・・・透明高分子フィルム
３・・・透明ハードコート層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a see-through touch panel used on a display screen such as a color CRT or a flat panel display.
[0002]
[Prior art]
Conventionally, a transparent touch panel used on a display screen such as a CRT or a flat panel display has a high transparency in order to prevent glare caused by glare from external light reflected on the display screen. A transparent hard coat film having a surface irregularity treatment on a molecular film is used. And as a surface uneven | corrugated process performed on this transparent polymer film, the transparent hard-coat layer containing the inorganic particle and synthetic resin particle of a comparatively uniform particle diameter is generally used.
[0003]
On the other hand, as CRT and flat panel displays used for touch panel displays are becoming more colored, the color of various displays has become higher definition. As a result, the conventional surface roughness treatment to prevent glare has been applied. When a hard coat film is used for a touch panel, a problem that a particularly white portion of a high-definition color screen looks glaring has arisen.
[0004]
[Problems to be solved by the invention]
Therefore, the object of the present invention is to prevent glare from appearing on the color screen even when affixed on the surface of a color display with high definition as described above, and to prevent glare from external light as in the past. However, there is a need to provide a touch panel with excellent display visibility, in which transparency does not deteriorate and image display is not blurred.
[0005]
[Means for Solving the Problems]
Therefore, the present inventor regularly forms the surface unevenness treatment of the transparent hard coat layer used in the conventional transparent hard coat film from inorganic particles and synthetic resin particles having a relatively uniform particle size. As a result of diligent research focusing on the fact that it is smooth, this regular and smooth surface irregularity acts as a lens, expanding the RGB emission points that are the basis of color display By emphasizing, the present inventors have solved the present invention by ascertaining that the white portion where all the light emitting points of RGB are emitting is particularly glaring on the screen.
[0006]
That is, the touch panel of the present invention is a see-through touch panel used on a color display screen, and has at least an ionizing radiation curable resin and two or more different averages on a transparent polymer film as a surface base material of the touch panel. A transparent hard coat layer composed of inorganic particles having a particle size is provided, and the inorganic particles are at least two types of silica having an average particle size of 1 to 4.5 μm and an average particle size of 5 to 50 nm, The coating layer has a thickness of 5 to 15 μm, and the content of inorganic particles having an average particle diameter of 1 to 4.5 μm and inorganic particles having an average particle diameter of 5 to 50 nm in the transparent hard coat layer is the ionizing radiation curable resin 100. The transparent hard coat film is 4.4 to 8 parts by weight with respect to parts by weight, respectively.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The transparent hard coat film 1 used as the surface substrate of the touch panel of the present invention will be described in more detail.
[0009]
The transparent hard coat film 1 of the present invention is obtained by forming a transparent hard coat layer 3 on a transparent polymer film 2, and the transparent hard coat layer 3 includes at least an ionizing radiation curable resin and two or more different average grains. It is composed of inorganic particles having a diameter.
[0010]
The transparency of the transparent hard coat film 1 in the present invention can be evaluated by the haze value in JIS-K7105 in a state where the transparent hard coat layer 3 is formed on the transparent polymer film 2, and the transparency is high. For excellent high transparency, the haze value is preferably 10% or less. Moreover, regarding the hard coat property of the transparent hard coat film 1 in the present invention, the pencil hardness in JIS-K5400 is H or more in the state where the transparent hard coat layer 3 is formed on the transparent polymer film 2 in the same manner. desirable.
[0011]
As the transparent polymer film 2, a film that does not hinder transparency, such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polypropylene, polyethylene, acrylic, acetylcellulose, vinyl chloride, can be used and stretched, particularly biaxially stretched. Since the mechanical strength and dimensional stability are improved, those are preferable. Although thickness can be suitably selected with respect to the material applied, generally it is 20-500 micrometers, Preferably it is 50-200 micrometers.
[0012]
The transparent hard coat layer 3 according to the present invention formed on the transparent polymer film 2 has a conflicting property of preventing glare due to external light without causing blurring of a display image caused by a decrease in transparency. (Hereinafter referred to as “transparency” and “glare prevention”, respectively), and the glare phenomenon of the screen that occurs when the RGB emission points of color display are enlarged and emphasized. That has no property (hereinafter referred to as “RGB glare prevention”).
[0013]
Such a transparent hard coat layer 3 is formed by coating and filming a composition comprising an ionizing radiation curable resin as a main component and mixing inorganic particles having two or more different average particle diameters, and ionizing radiation (ultraviolet rays or electrons). It can be obtained by irradiating (line) and curing by crosslinking.
[0014]
As the ionizing radiation curable resin, a photopolymerizable prepolymer that can be crosslinked and cured by irradiation with ionizing radiation (ultraviolet ray or electron beam) can be used. An acrylic prepolymer having at least one acryloyl group and having a three-dimensional network structure by crosslinking and curing is particularly preferably used. As this acrylic prepolymer, urethane acrylate, polyester acrylate, epoxy acrylate, melamine acrylate and the like can be used. These can be used alone, but it is preferable to add a photopolymerizable monomer, a photopolymerization initiator, an ultraviolet sensitizer, etc., in order to further improve the crosslinkability and the hardness of the crosslinked cured coating film.
[0015]
Photopolymerizable monomers include trimethylolpropane trimethacrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate, dipentaerythritol monohydroxypentaacrylate, neopentyl glycol diacrylate, tripropylene glycol triacrylate, diethylene glycol diacrylate, 1, A polyfunctional monomer such as 6-hexanediol diacrylate is exemplified.
[0016]
Examples of the photopolymerization initiator include acetophenone, benzophenone, Michler's ketone, benzoin, benzylmethyl ketal, benzoylbenzoate, α-acyloxime ester, thioxanthones, and the like, and examples of the ultraviolet sensitizer include n-butylamine, triethylamine, tri- and n-butylphosphine.
[0017]
This ionizing radiation curable resin imparts a hard coat property to the transparent hard coat layer 3 and has transparency and antiglare property and RGB antiglare property when combined with inorganic particles described later. It will be able to demonstrate.
[0018]
Therefore, as long as the above-described effects can be exhibited, it is possible to mix other thermoplastic resins and thermosetting resins with the ionizing radiation curable resin as the resin for forming the transparent hard coat layer 3.
[0019]
Examples of such thermoplastic resins include cellulose derivatives such as acetylcellulose, nitrocellulose, acetylbutylcellulose, ethylcellulose, methylcellulose, vinyl acetate and copolymers thereof, vinyl chloride and copolymers thereof, vinylidene chloride and copolymers thereof. Vinyl resins such as polyvinyl acetal resins such as polyvinyl formal and polyvinyl butyral, acrylic resins and copolymers thereof, acrylic resins such as methacrylic resins and copolymers thereof, polystyrene resins, polyamide resins, linear polyester resins, polycarbonate resins Etc.
[0020]
Examples of the thermosetting resin include a thermosetting urethane resin composed of an acrylic polyol and an isocyanate prepolymer, a phenol resin, a urea melamine resin, an epoxy resin, an unsaturated polyester resin, and a silicone resin.
[0021]
Next, the inorganic particles in the present invention are one kind of inorganic pigments or inorganic extender pigments such as silica, alumina, talc, clay, calcium carbonate, magnesium carbonate, barium sulfate, aluminum hydroxide, titanium dioxide, and zirconium oxide. Alternatively, two or more of the two types having different average particle diameters are used in combination.
[0022]
In this case, as a preferred embodiment of the inorganic particles having two or more different average particle diameters, at least one of the average particle diameters is a relatively large inorganic particle of 1 to 15 μm, and the other average particle diameter is 5 to 50 nm. It is preferable to combine inorganic particles having relatively small particles. As a mixing ratio thereof, the relatively large inorganic particles having an average particle diameter of 1 to 15 μm are 1 to 8 parts by weight, preferably 2 to 6 parts by weight with respect to 100 parts by weight of the ionizing radiation curable resin. Desirably, the relatively small inorganic particles having an average particle diameter of 5 to 50 nm are 1 to 8 parts by weight, preferably 2 to 6 parts by weight, based on 100 parts by weight of the ionizing radiation curable resin.
[0023]
Such inorganic particles having two or more different average particle sizes can be combined with the above-mentioned ionizing radiation curable resin so as to have transparency and antiglare property and to exhibit RGB antiglare property. become.
[0024]
As described above, the transparent hard coat layer 3 according to the present invention is obtained by mixing the inorganic particles with the ionizing radiation curable resin, thereby causing the wavy unevenness generated specifically on the surface of the ionizing radiation curable resin coating film containing particulate matter. By utilizing (FIG. 1), sufficient antiglare property and RGB glare prevention property are exhibited while maintaining high transparency by reducing the amount of inorganic particles that are granular materials.
[0025]
The thickness of the transparent hard coat layer 3 is not limited as long as it is within a range that satisfies the above-mentioned performance, but can be appropriately adjusted within a range of 2 to 15 μm, preferably 3 to 8 μm.
[0026]
The ultraviolet ray irradiated to crosslink and cure the transparent hard coat layer 3 is preferably 100 to 400 nm having an energy of 50 to 300 kcal / mol using an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a metal halide lamp, or the like. Is used in a wavelength region of 200 to 400 nm.
[0027]
Similarly, a scanning or curtain type electron beam accelerator is used as the electron beam, and an electron beam having an acceleration voltage of 1000 keV or less, preferably 100 to 300 keV and having a wavelength region of 100 nm or less is used.
[0028]
As described above , the touch panel of the present invention is a transparent hard coat layer in which the surface base material of the touch panel is composed of at least an ionizing radiation curable resin and inorganic particles having two or more different average particle diameters on a transparent polymer film. It is extremely easy to prevent glare caused by glare caused by reflection of external light and to prevent difficulty in viewing caused by RGB glare. It will be excellent in visibility.
[0029]
【Example】
Examples of the present invention will be described below. “Part” and “%” are based on weight unless otherwise specified.
[0030]
[Examples 1 to 3]
On one surface of a polyethylene terephthalate film 2 having a thickness of 100 μm (Cosmo Shine A4300: Toyobo Co., Ltd.), the transparent hard coat layer coating liquids a to c having the composition shown in Table 1 were applied and dried by heating at 60 ° C. for 5 minutes, The transparent hard coat film 3 of Examples 1 to 3 was produced by forming a transparent hard coat layer 3 of about 5 μm by irradiating ultraviolet rays with a high pressure mercury lamp for 1 to 2 seconds.
[0031]
[Comparative Examples 1-4]
On one surface of a polyethylene terephthalate film (Cosmo Shine A4300: Toyobo Co., Ltd.) having a thickness of 100 μm, the transparent hard coat layer coating liquids d to g having the composition shown in Table 2 were applied, dried by heating at 60 ° C. for 5 minutes, A transparent hard coat layer of about 5 μm was formed by irradiating ultraviolet rays with a mercury lamp for 1 to 2 seconds to produce transparent hard coat films of Comparative Examples 1 to 4.
[0032]
[Comparative Example 5]
A transparent hard coat layer coating solution h having the composition shown in Table 2 was applied to one surface of a polyethylene terephthalate film (Cosmo Shine A4300: Toyobo Co., Ltd.) having a thickness of 100 μm, and dried by heating and curing at 120 ° C. for 5 minutes. A 5 μm transparent hard coat layer was formed to produce a transparent hard coat film.
[0033]
In Tables 1 and 2, resin A is an ionizing radiation curable resin (Diabeam UR6530: Mitsubishi Rayon Co., Ltd.), and resin B is a thermoplastic acrylic resin (LMS-55 <solid content 40%>: Kyoyo Chemical Industry Co., Ltd.) ), Resin C is a thermoplastic acetal resin (ESREC BL-S: Sekisui Chemical Co., Ltd.), resin D is a thermosetting silicone resin (Si coat 900 <solid content 30%>: Daihachi Chemical Co., Ltd.), inorganic particles E Is porous silica (Silicia 446 <average particle size 4.5 μm>: Fuji Silysia Chemical Co.), inorganic particles F are fine powder silica (Aerosil 50 <average particle size 30 nm>: Nippon Aerosil Co., Ltd.), and additive G is photopolymerized. An initiator (Irgacure 651: Ciba Specialty Chemicals) was used.
[0034]
[Table 1]

[0035]
[Table 2]

[0036]
Table 3 shows the results of evaluating the visibility (transparency, glare prevention, RGB glare prevention) of the transparent hard coat film obtained as described above. Evaluation of transparency, glare prevention property, and RGB glare prevention property was performed as follows.
[0037]
[transparency]
When haze value “%” (JIS-K7105) is measured using SM color computer HGM-2K (Suga Test Instruments Co., Ltd.), display image when transparent hard coat film is laminated on CRT screen displaying image It was visually evaluated whether or not it was blurred. As a result of the visual evaluation, “Good” was given as good, and “X” was bad.
[0038]
[Glare prevention]
When glossiness “%” (JIS-K5400) is measured using SM color computer UGV-5K (Suga Test Instruments Co., Ltd.) and transparent hard coat film is laminated on the CRT screen displaying the image, external light A visual evaluation was made as to whether or not the display image would be difficult to see due to the reflection of. As a result of the visual evaluation, “Good” was given as good, and “X” was bad.
[0039]
[RGB glare prevention]
When a transparent hard coat film was laminated on a CRT screen on which a color image was displayed, the RGB light emission points of the color display were enlarged and emphasized, and whether or not the white portion of the display screen was particularly glaring was visually evaluated. As a result of the visual evaluation, “Good” was given as good, and “X” was bad.
[0040]
[Visibility]
As a comprehensive evaluation, “◯” indicates that all three evaluations of transparency, glare prevention, and RGB glare prevention were good, and “×” indicates that any one of the three evaluations was bad.
[0041]
[Table 3]

[0042]
As is clear from the results in Table 3, the transparent hard coat films 1 of Examples 1 to 3 had excellent visibility in all of transparency, glare prevention properties, and RGB glare prevention properties.
[0043]
On the other hand, the transparent hard coat films of Comparative Examples 1 and 3 have antiglare properties because of their low glossiness, but the transparent hard coat layer has a relatively large particle size as the inorganic particles. Since only the types are included, the glare of the screen due to the RGB emission points cannot be suppressed, and the visibility is very poor. In particular, the transparent hard coat film of Comparative Example 3 had a high haze value and was inferior in terms of transparency.
[0044]
Moreover, since the transparent hard coat film of Comparative Examples 2 and 4 contains only one kind of inorganic hard particles having a relatively small particle size, the haze value is low and the transparency is excellent. However, the glossiness was high, the antiglare property was extremely low, and the visibility was very poor. Since the transparent hard coat layer does not contain inorganic particles having a relatively large particle size, the glossiness was not lowered, but surface irregularities did not occur. There was no glare on the screen.
[0045]
Moreover, since the transparent hard coat film of Comparative Example 5 uses a thermosetting resin instead of an ionizing radiation curable resin, the amount of inorganic particles added is the same as that of the ionizing radiation curable resin (Example 1). Even if the transparency is kept equal, there is no wavy unevenness that occurs when mixing granular materials with ionizing radiation curable resin, the glossiness is high and antiglare property cannot be obtained, Since the RGB glare prevention property was not obtained, the visibility was very poor.
[0046]
【The invention's effect】
In the touch panel of the present invention, the surface base material of the touch panel is provided with a transparent hard coat layer composed of at least an ionizing radiation curable resin and inorganic particles having two or more different average particle diameters on a transparent polymer film. As a result, even when used on a high-definition color display surface, the color screen does not appear glaring, and glare against external light is prevented and transparency is lowered and image display is blurred. It is possible to obtain a touch panel with excellent display visibility.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing one embodiment of a transparent hard coat film of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Transparent hard coat film 2 ... Transparent polymer film 3 ... Transparent hard coat layer

Claims (2)

A transparent touch panel used on a color display screen, comprising a transparent polymer film and at least an ionizing radiation curable resin and inorganic particles having two or more different average particle diameters as a surface substrate of the touch panel. The inorganic particles are at least two types of silica having an average particle diameter of 1 to 4.5 μm and an average particle diameter of 5 to 50 nm, and the thickness of the transparent hard coat layer is 5 to 15 μm. And the contents of the inorganic particles having an average particle diameter of 1 to 4.5 μm and the inorganic particles having an average particle diameter of 5 to 50 nm in the transparent hard coat layer are each 4 parts by weight based on 100 parts by weight of the ionizing radiation curable resin. A touch panel comprising a transparent hard coat film of 4 to 8 parts by weight.   The touch panel according to claim 1, wherein the display is a CRT display.

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