TW201339220A - Hard-coat film, hard-coat membrane, and electronic device - Google Patents

Abstract

Provided is a cross-linked cured system using an alkylphenone-based photopolymerization initiator, specifically, a non-colored hard-coat film and hard-coat membrane. A hard-coat layer comprising a cross-linked cured product obtained by irradiating a curable composition with ionizing radiation, the curable composition containing an ionizing-radiation-curable resin and an alkylphenone-based photopolymerization initiator as well as a hindered-phenol-based antioxidant, wherein the hindered-phenol-based antioxidant used preferably has a molecular weight of at least 700, and an alpha-hydroxyalkylphenone-based photopolymerization initiator, particularly 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one, is preferably used as the alkylphenone-based photopolymerization initiator.

Description

Hard coated film, hard coated film and electronic machine

The present invention relates to an electronic device having a hard coat film of a hard coat layer, a hard coat film constituting a hard coat layer, and a touch panel or the like.

【Background technique】

In order to prevent damage to the surface of various electronic devices, printed matter, etc., the protective film is bonded.

As such a protective film, a hard coat film which is formed on a substrate by using a hard coat layer formed of a cured product of a curable resin is suitably used. In particular, a hard coat film using an ionizing radiation curable resin as a curable resin is effective in preventing damage (Patent Document 1).

The hard coat layer using the ionizing radiation-curable resin is irradiated with ionizing radiation by a curable composition containing an ionizing radiation curable resin and a photopolymerization initiator, and is hardened to form a hard coat layer.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Laid-Open Patent Publication No. 2000-214791 (Embodiment)

[Summary of the Invention]

Photopolymerization initiators used together with ionizing radiation-curable resins, Several forms. Among them, in the state in which an alkylphenol-based photopolymerization initiator is used, there is a problem that a hard coating film obtained by coloring occurs.

On one aspect of the present invention, a cross-linking hardening system using an alkylphenol-based photopolymerization initiator provides an uncolored coating film. Specifically, a colorless hard coat film and a hard coat film are provided. On the other hand, an electronic device having a hard coated film which is not colored like this is provided.

The present inventors have found that when a specific oxidation preventing agent is contained in an ionizing radiation-curable resin composition using an alkylphenol-based photopolymerization initiator, it is prevented from being formed by a cured product of the composition. The coating is colored to complete the present invention.

The hard coat film of the present invention is characterized in that it has a hard coat layer formed of a cured product of a curable composition, and the curable composition contains an ionizing radiation curable resin and an alkylphenol photopolymerization. Starting agent and hindered phenolic oxidation inhibitor.

The hard coat film of the present invention is characterized in that it is composed of a cured product of a curable composition, and the curable composition contains an ionizing radiation curable resin, an alkylphenol photopolymerization initiator, and a hindered phenol. It is an oxidation inhibitor.

The curable composition of the present invention is characterized by comprising an ionizing radiation curable resin, an alkylphenol photopolymerization initiator, and a hindered phenol oxidation inhibitor.

An electronic device according to the present invention is characterized in that the hard coat film of the present invention is disposed and configured with respect to the main body of the electronic device such that the hard coat layer becomes the surface side. Hard coating in the present invention In the state in which the film is formed by laminating a hard coat layer on a substrate, the electronic device of the present invention arranges and constitutes the hard coat film of the present invention with respect to the main body of the electronic device such that the base material layer faces each other.

The present invention encompasses the following aspects.

(1) As the hindered phenolic oxidation preventing agent, a molecular weight of 700 or more can be used.

(2) The content of the curable composition is an alkylphenol-based photopolymerization initiator in an amount of 1 part by weight or more and 5 parts by weight or less based on 100 parts by weight of the ionizing radiation-curable resin. Oxidation preventing agent: 0.5 part by weight or more and 5 parts by weight or less.

(3) As the alkylphenol-based photopolymerization initiator, an α-hydroxyalkylphenol-based photopolymerization initiator can be used, and as the α-hydroxyalkylphenol-based photopolymerization initiator, 1-[4 can be used. -(2-Hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one.

According to the present invention, the hard coating layer is formed by containing a cured product of an ionizing radiation-curable resin, an alkylphenol-based photopolymerization initiator, and a curable composition of a hindered phenol-based oxidation inhibitor. A non-colored hard coating film and a hard coating film are provided. Along with this, it is also possible to provide an electronic machine having a hard coat film without coloring.

The curable composition of the present invention contains an ionizing radiation-curable resin, an alkylphenol-based photopolymerization initiator, and a hindered phenol-based oxidation inhibitor, and is therefore suitable for a non-colored hard coating film and a hard coating film. Manufacturing.

Embodiment of the Invention

An example of the hard coat film and the hard coat film of the present invention will be described below.

The hard coat film of the present example is an example in which a laminated structure of a hard coat layer is laminated on a substrate. Further, the hard coat film of the present invention is not limited to the laminated structure of the present example, and can be a hard coat layer of a single layer in a state in which it can be handled separately, and can constitute a hard coat film of the present example.

As a substrate series, plastic film (for example, by polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyethylene, polypropylene, polyphenyl) A variety of films formed of materials such as ethylene, triethylenesulfonyl cellulose, and propylene, or glass. Even among these, in terms of mechanical strength or dimensional stability, it is preferable to extend the processing, particularly the polyethylene terephthalate film which is subjected to biaxial stretching processing. Further, it is also suitable to use a method of improving the bonding property with the hard coat layer by performing a corona discharge treatment on the surface of the substrate or by providing an easy-bonding layer. The thickness of the substrate is generally 25 to 500 μm, preferably 50 to 200 μm.

The hard coat layer (hard coat film) of the present example is composed of a cured product of a curable composition.

The curable composition of the present example contains an ionizing radiation curable resin and a photopolymerization initiator together.

As the ionizing radiation-curable resin, a photopolymerizable prepolymer which is crosslinked and hardened by irradiation with ionizing radiation (ultraviolet rays or electron beams) can be used.

In the case where the photopolymerizable prepolymerization system has two or more acrylonitrile groups in one molecule, it is particularly preferable to use cross-linking to harden by the viewpoint of further increasing the hardness of the hard coat layer. It is a propylene-based prepolymer (hard prepolymer) having a three-dimensional mesh structure. As a propylene system The poly system includes, for example, urethane acrylate, polyester acrylate, epoxy acrylate, melamine acrylate, polyfluoroalkyl acrylate, fluorenone acrylate, and the like. These lines can be used singly or in combination of several kinds. The photopolymerizable prepolymerization system can be used alone as an ionizing radiation curable resin. However, in order to improve the crosslinking hardenability and to increase the hardness of the hard coat layer, it is preferred to use a photopolymerizable monomer in combination.

Examples of the photopolymerizable monomer series include a monofunctional propylene monomer (for example, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, butoxyethyl acrylate, etc.), Bifunctional propylene monomer (eg 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, polyethylene glycol diacrylate, hydroxytrimethyl b) A neofunctional pentylene glycol diacrylate or the like, a polyfunctional propylene monomer (for example, dipentaerythritol hexaacrylate, trimethylpropane triacrylate, pentaerythritol triacrylate, etc.). These lines can be used singly or in combination of several kinds.

In this example, an ionizing radiation curable organic-inorganic hybrid resin can be used as the ionizing radiation curable resin. The so-called ionizing radiation-curable organic-inorganic hybrid resin is different from the composite glass fiber reinforced plastic (FRP) which has been represented since ancient times. The mixing method of organic matter and inorganic matter becomes tight, and the dispersion state is molecular level or close to this. The inorganic component and the organic component can be reacted by irradiation with ionizing radiation to form a coating film.

The inorganic component in the mixed resin is a metal oxide such as cerium oxide or titanium dioxide, but is preferably cerium oxide. As the ceria series, a reactive cerium oxide having a photopolymerizable photosensitive group is introduced on the surface. The reactive cerium oxide-based average particle diameter is preferably 1 nm or more, more preferably 100 nm or less, still more preferably 10 nm or less. By using reactive ceria having an average particle diameter within a predetermined range, it is easy to maintain transparency when it is a coating film. in The content of the inorganic component in the mixed resin is preferably 65% by weight or less, and more preferably 40% by weight or less. When the content of the inorganic component is 65% by weight or less, the transparency at the time of being a coating film can be easily maintained.

As the organic component in the mixed resin, the above-mentioned inorganic component (preferably, reactive ceria) and a compound having a polymerizable polymerizable unsaturated group (for example, having two or more polymerizable unsaturated groups in the molecule) The polyvalent unsaturated organic compound is a monovalent unsaturated organic compound having one polymerizable unsaturated group in the molecule, and the like.

As the photopolymerization initiator, an alkylphenol photopolymerization initiator is used. Because it is beneficial to the aspect of versatility. Examples of the alkylphenol-based photopolymerization initiator include a benzoin-based system and a benzyl ketal-based (for example, 2,2-dimethoxy-1,2-diphenylethane-1-one). Α-hydroxyalkylphenol (for example, 1-hydroxy-cyclohexyl-phenyl-one, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-[4-(2-hydroxyl) Ethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionate) ))-benzyl]phenyl}-2-methyl-propan-1-one, etc.), α-aminoalkylphenol (eg 2-methyl-1-(4-methylthiophenyl) -2-morpholinpropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone-1, 2-(dimethylamino)- 2-[(4-Methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone or the like). These lines can be used singly or in combination of several kinds.

Even among these, an α-hydroxyalkylphenol system is preferred, and 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1 is particularly preferred. - Propane-1-one. The details are described later, but in the state where the ionizing radiation hardening type resin is used for crosslinking and hardening using an α-hydroxyalkylphenol-based photopolymerization initiator, ionization radiation can be reduced. It is easy to prevent red coloration of the hard coat layer by the amount of the radical-containing substance generated by the irradiation (considering the starting material of the by-product of the red coloring source, which is described later).

The alkylphenol-based photopolymerization initiator is preferably 1 part by weight or more, more preferably 2.5 parts by weight or more, and most preferably 5 parts by weight to 100 parts by weight of the ionizing radiation-curable resin in the curable composition. The alkylphenol-based photopolymerization initiator is contained in an amount of 4.5 parts by weight or less, more preferably 4.5 parts by weight or less. The hardness of the hard coat layer can be increased by 1 part by weight or more, and the hard coat layer can be prevented from being colored by 5 parts by weight or less.

The inventors of the present invention are faced with the use of an alkylphenol-based photopolymerization initiator which is advantageous for general versatility and which is subjected to cross-linking and hydrazine hardening of an ionizing radiation-curable resin. The hard coat layer composed of the cured product after cross-linking and hardening has a problem of being colored in red. When attempting to investigate the cause, it is considered that it is because a part of the radical-containing substance generated by irradiation of the ionizing radiation of the alkylphenol-based photopolymerization initiator does not attack the monomer or the oligomer, and dimerizes itself. A by-product is produced, and a by-product (a radical-containing substance is dimerized) is present in the cured product, and is a hard coating layer to cause red coloration.

As a result of repeated review, in the present example, an alkylphenol photopolymerization initiator and a hindered phenol oxidation inhibitor were used together. In other words, in the present embodiment, the curable radiation-curable resin and the alkylphenol-based photopolymerization initiator and the hindered phenol-based oxidation inhibitor are contained together. By using a specific oxidation preventing agent as described above, it is possible to reduce the amount of by-products generated during the polymerization reaction by reacting with a radical-containing substance generated by irradiation with an ionizing radiation of an alkylphenol-based photopolymerization initiator. At the end, the hard coat layer is prevented from red coloring.

The series of hindered phenolic oxidation inhibitors are, for example, those represented by the following structural formulae (1) to (4). Even among these, it is best to prevent the hardness of the hard coating layer from falling. The structural formulas (1) and (2) which are low and are easy to prevent redness. Further, the structural formula (2) is preferable even in the case where the hardness of the hard coating layer due to the side effect of the oxidation preventing agent is less likely to occur.

The hindered phenolic oxidation preventing agent is preferably a molecular weight of 700 or more, more preferably 750 or more. By using a molecular weight of 700 or more, it is easy to prevent the hard coating layer from red coloring, and it is easy to suppress the hardness reduction of the hard coating layer.

The hindered phenolic oxidation preventing agent is preferably one or more hydroxyl groups in the molecule. By including three or more hydroxyl groups in the molecule, it is easy to prevent the hard coating layer from red coloring, and it is easy to suppress the hardness reduction of the hard coating layer.

The hindered phenolic oxidation inhibitor is preferably contained in an amount of 0.5 part by weight or more, more preferably 1 part by weight or more, and most preferably 5 parts by weight or less based on 100 parts by weight of the ionizing radiation-curable resin in the curable composition. More preferably, it is an amount of 3 parts by weight or less. When the amount is 0.5 parts by weight or more, the hard coating layer can be easily prevented from being colored by red, and the hardness of the hard coating layer can be prevented from being lowered by 5 parts by weight or less.

In this embodiment, it is preferred to contain a photopolymerization accelerator in the curable composition. The photopolymerization accelerator can accelerate the curing speed by reducing the polymerization barrier caused by the air during hardening. Examples of such a photopolymerization accelerator include, for example, p-dimethylamino benzoic acid isoamyl ester and p-dimethylamino benzoic acid ethyl ester.

In order to impart anti-glare property, block preventive property, Newton's ring preventability, and the like to the curable composition, particles may be contained. Examples of the particles include inorganic particles (for example, ceria, alumina, talc, clay, calcium carbonate, magnesium carbonate, barium sulfate, aluminum hydroxide, titanium oxide, zirconium oxide, etc.) or resin particles (for example, propylene resin particles, anthrone). Resin particles, nylon resin particles, styrene resin particles, polyethylene resin particles, benzoguanamine resin particles, urethane resin particles, and the like.

In the state in which the block prevention property is considered, as the particle system, a particle diameter of preferably 10 nm or more, more preferably 50 nm or more, more preferably 500 nm or less, still more preferably 200 nm or less is used. By using particles having a particle diameter in such a range, the transparency can be maintained, and the block preventive property can be exhibited in the cured product (hard coat layer).

An additive such as a leveling agent or an ultraviolet absorber may be added to the curable composition.

The hardenable composition of this example is usually achieved by the form of a coating. A resin component composed of the ionizing radiation-curable resin, the photopolymerization initiator, and the oxidation preventing agent described above may be dissolved or dispersed by a solvent to be diluted by an organic solvent or the like in an organic solvent-based coating material. Further, after adding other additives, a curable composition is produced by adding an additive as needed. In the state of being an inorganic solvent-based paint, a further addition component may be added to the above-mentioned resin component as needed to form a curable composition.

The cured product of the present example (that is, the hard coat layer of the present example) can be applied to a substrate by the curable composition of the present example, dried, irradiated with ionizing radiation, and crosslinked and hardened to form a cured product. . As a series of methods for irradiating ionizing radiation, a method of irradiating ultraviolet rays in a wavelength range of 100 nm to 400 nm, preferably 200 nm to 400 nm, which is emitted by an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, or a metal halide lamp, or A means of illuminating an electron beam of a wavelength region of 100 nm or less emitted by a scanning type or curtain type electron beam accelerator. The amount of irradiation of the ionizing radiation is about 400 to 1000 mJ/cm 2 in the state of ultraviolet rays with a cumulative irradiation amount.

The thickness of the hard coat layer of this example is usually about 2 to 8 μm.

In the case of the hard coat layer of the present example, it is preferable that the pencil hardness of JIS-K5400:1990 is H or more, more preferably 2 H or more, and even more preferably 3 H or more.

The hard coat layer of this example can be formed on both sides of the substrate. Alternatively, the hard coat layer of the present example may be provided on one side of the substrate, and a general hard coat layer may be provided on the other side.

The hard coat film of the present example is suitably used for, for example, a surface of a display device such as a cover glass, a window glass, a display window, or the like of an electronic machine body or a timepiece or a calculation measuring device, and the substrate is disposed to be opposed and protected. Its surface. It is best to use it on the surface protection of the electronic machine body.

That is, the electronic device of the present example is configured such that the hard coat film of the present example is disposed on the main body of the electronic device such that the substrate side thereof faces.

Examples of the electronic device include a display device such as a liquid crystal display device, a CRT display device, a plasma display device, and an EL display device, and a portable information terminal or a personal computer or a touch panel including the display device.

As an electronic device, it is preferable to cite a touch surface which is strongly required to have transparency. A board (a resistive touch panel, a capacitive touch panel, etc.) is particularly preferably an electrostatic capacitive touch panel.

The resistive touch panel has an upper electrode of a transparent conductive layer disposed on one side of the transparent substrate through the spacer and a lower electrode of the transparent conductive layer on a side of the transparent substrate, such that the upper electrode and the lower portion The transparent conductive layers of the electrodes are constructed in a substantially opposite structure.

In such a resistive touch panel, a hard coat film of the present example can be used as the transparent substrate of the upper electrode, or a hard coat film of the present example can be disposed on the transparent substrate of the upper electrode.

The capacitive touch panel can be divided into a surface Capacitive and a Projected Capacitive.

The surface type is constituted by a basic structure including a transparent conductive film and a protective layer on one side of the substrate and an electrode disposed at four corners. As the substrate and the transparent conductive film constituting the surface type capacitive touch panel, a conventional transparent conductive film substrate can be used. In such a surface type capacitive touch panel, a hard coat film of the present example is used as a protective layer, or a hard coat film of the present example is disposed on a protective layer.

The projection type is formed on the transparent substrate and has an X-axis trajectory which is formed along the predetermined first direction and which is an X-axis trajectory of the conductive element group, and is formed along the second direction intersecting the X-axis trajectory and becomes a conductive element group. The shaft trajectory is configured by a basic structure in which at least the insulating layer of the intersection portion of the X-axis trajectory and the Y-axis trajectory and the connection wiring connected to the external take-out line are disposed. In the above-described projection type capacitive touch panel, the hard coat film of the present example is used as the transparent substrate, or the hard coat film of the present example is placed on the transparent substrate.

The transparency of the surface of the hard coated film is ensured by an electronic device constructed by such an electronic device body and a hard coat film disposed on the surface of the body.

[Examples]

In the following, examples which are embodied by the embodiments of the present invention will be described in more detail. In addition, in the present embodiment, "parts by weight" and "%" are based on weight unless otherwise indicated.

1. Production of hard coated film

On one side of a transparent polyester film (Cosmoshine A4350: Toyobo Co., Ltd.) having a thickness of 125 μm, the hard coating layer coating solution of the following formulation was applied, and dried and irradiated with ultraviolet rays to form a hard coat layer having a thickness of 7 μm. A hard coated film of each example was obtained.

<hard coating layer coating liquid>

̇ ionizing radiation hardening resin (solid component 80%) 125 parts by weight

(Unidic17-813: DIC company)

Decyl phenol photopolymerization initiator

(The types and addition amounts of photopolymerization initiators are shown in Table 1)

Antimony hindered phenolic oxidation inhibitor

(The type and amount of oxidation inhibitor are listed in Table 1)

̇Diluting solvent 245 parts by weight

2. Evaluation

The following evaluation was performed on the hard coat film obtained by each example. The results are shown in Table 1.

1. The color of the hard coating layer

The hard coated film produced was cut into a size of 5 cm × 5 cm, and 10 sheets were laminated, starting from the upper direction and the lateral direction, and the chromaticity of the laminate was observed by visual observation. As a result, starting from any direction In the case where the coloring is invisible, it is "◎", and the red color is not colored in the above direction, and the red color is thinly seen in the horizontal direction, and it is "○". The red color is thinly seen in the above direction and the red color is strongly seen in the horizontal direction. For those who are in the "△", they will see the redness in a strong direction in any direction.

2. Hardness

The pencil hardness of the surface of the produced hard coated film was measured (JIS-K5600-5-4: 1999).

The A~G series in Table 1 are as follows.

[Photopolymerization initiator]

A: Product name "Irgacure 2959 (Material name: 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one) of Ciba Corporation, Japan" B: The product name "Irgacure184" of Ciba Japan, and the product name "Irgacure907" of Ciba Japan.

[oxidation inhibitor]

D: The name of the product of Japanese Ciba company "Irganox1010/ corresponds to chemical formula (1)", E: Product name "AO-20/corresponding to chemical formula (2)" by Ciba Corporation of Japan, F: Product name "Irganox245/corresponding to chemical formula (3)" by Ciba Japan, G: Product name "Irganox259" of Ciba Japan / corresponds to chemical formula (4)".

3. Investigation of the results

As is clear from the results of Table 1, in Examples 1 to 12 in which an alkylphenol-based photopolymerization initiator was used in combination with a hindered phenol-based oxidation preventing agent, a hard coating layer was prevented as compared with Comparative Examples 1 to 3. The red degree.

In particular, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one (an example of an α-hydroxyalkylphenol system) is used. Examples 1 to 10 which are alkylphenol-based photopolymerization initiators are more easily prevented than other examples (Examples 11 and 12) using an alkylphenol-based photopolymerization initiator other than this. The redness of the hard coat layer.

Further, in Examples 1 to 8 in which the chemical formulas (1) and (2) were used as the hindered phenol-based oxidation preventing agent, the hardness of the hard coating film due to the side effect of the oxidation preventing agent was less likely to occur. In particular, in Examples 6 to 8, 11, and 12 in which the hindered phenol-based oxidation preventing agent of the chemical formula (2) is used, the hindered phenol-based oxidation preventing agent can prevent the redness of the hard coating layer even in a small amount.

Claims (8)

A hard coating film comprising a hard coating layer having a hard coating layer, wherein the hard coating layer is formed of a cured product of a curable composition, and the hardening composition comprises ionization. A radiation-curable resin, an alkylphenol-based photopolymerization initiator, and a hindered phenol-based oxidation inhibitor. The hard coat film according to the first aspect of the invention, wherein the hindered phenolic oxidation preventive agent has a molecular weight of 700 or more. The hard coat film according to the first or second aspect of the invention, wherein the curable composition is an alkylphenol photopolymerization initiator based on 100 parts by weight of the ionizing radiation curable resin. 1 part by weight or more and 5 parts by weight or less of the hindered phenol-based oxidation inhibitor: 0.5 parts by weight or more and 5 parts by weight or less. The hard-coated film according to any one of the above-mentioned claims, wherein the alkylphenol-based photopolymerization initiator is an α-hydroxyalkylphenol-based photopolymerization initiator. The hard coat film according to the fourth aspect of the invention, wherein the α-hydroxyalkylphenol photopolymerization initiator is 1-[4-(2-hydroxyethoxy)-phenyl]- 2-hydroxy-2-methyl-1-propan-1-one. A hard coating film comprising a hard coating film formed of a cured product of a curable composition, wherein the curable composition comprises an ionizing radiation curable resin and an alkylphenol photopolymerization start. Agent and hindered phenolic oxidation inhibitor. An electronic device characterized in that the hard coat film according to any one of claims 1 to 5 is disposed such that the hard coat layer becomes a surface side with respect to the electronic machine body. The electronic device according to claim 7, wherein the electronic device of the present invention is a touch panel.