JP6171389B2 - Hard coat film - Google Patents

Description

  The present invention relates to a hard coat film having a hard coat layer.

  Conventionally, optical films for anti-reflection used for various displays use active energy ray-curable resin on the surface of the substrate in consideration of scratch resistance, chemical resistance and weather resistance in addition to optical characteristics. The hard coat layer was often provided. However, the refractive index of the hard coat layer obtained by this active energy ray curing is often different from the refractive index of the substrate used. For this reason, the interference between the light reflected from the surface of the hard coat layer and the light reflected from the interface between the hard coat layer and the base material causes rainbow-colored unevenness (interference fringes), degrading the visibility of the display. Also, it detracted from the aesthetics of the display.

  The resin used for the hard coat layer usually has a refractive index of about 1.5 to 1.6. On the other hand, the refractive index of the substrate is, for example, about 1.65 for polyethylene terephthalate and about 1.45 for triacetyl cellulose. Therefore, when the interface between the hard coat layer and the substrate is clear, reflection of light at the interface occurs due to the difference in refractive index. Therefore, interference between the reflected light on the surface of the hard coat layer and the reflected light on the interface occurs, resulting in rainbow-colored interference unevenness (interference fringes).

  Techniques for suppressing the interference fringes are disclosed in Patent Document 1 and Patent Document 2. In order to reduce the difference in refractive index between the base material and the hard coat layer, the interference fringe reduction technique described in Patent Document 1 provides unevenness at the interface between the base material and the hard coat layer. This technique scatters the reflection of light at the interface. In addition, the interference fringe prevention technique described in Patent Document 2 uses a resin containing a solvent that dissolves or swells the base material, and applies the hard coat layer to the base material, thereby interposing the base material and the hard coat layer between them. This is a technique for producing an intermediate layer and reducing the refractive index difference at the interface between the substrate and the hard coat layer.

JP 2005-107005 A JP 2003-205563 A

  However, in the case of the technique described in Patent Document 1, a step of providing irregularities on the substrate surface is required before applying the hard coat layer to provide irregularities on the substrate, and this method requires a number of steps. There is a problem that it increases and leads to cost increase. Furthermore, since the unevenness is imparted, there is a problem that the transparency of the film itself is lowered. Moreover, in the case of the technique described in Patent Document 2, since the base material is dissolved or swollen, there is a problem that the surface hardness of the film is lowered.

  In view of the above points, an object of the present invention is to provide a hard coat film having high surface hardness and excellent transparency while effectively suppressing or preventing the occurrence of interference fringes.

  As a result of intensive studies, the present invention uses an ionizing radiation curable oligomer having a molecular weight of 1000 or less and containing two functional groups represented by the general formula (I) in one molecule. Thereby, it is possible to provide a hard coat film having high surface hardness and excellent transparency while reducing the difference in refractive index with the hard coat layer and effectively suppressing or preventing the occurrence of interference fringes.

In the first invention, the hard coat film has a base layer and a hard coat layer formed on at least one side of the base layer, and the base layer has a functional group represented by the general formula (I). It consists of a cured film of a composition containing an ionizing radiation curable oligomer having a molecular weight of 1,000 or less contained in one molecule and a photopolymerization initiator, and the hard coat layer comprises an ultraviolet curable resin and a photopolymerization initiator. It consists of a cured film of the hard coat composition it contains , and the ionizing radiation curable oligomer is a compound represented by the following formula (II) .
(In the formula, R ₁ represents hydrogen or a methyl group.)

  The second invention is characterized in that, in the first invention, the hardness of the pencil hardness test (4.9 N load) specified in JIS K5600-5-4 (1999) is 4H or more.

  The hard coat film of the present invention can provide a hard coat film having high surface hardness and excellent transparency while effectively suppressing or preventing the occurrence of interference fringes, and improving the visibility of the display. In addition, the hardness of the display surface can be improved.

Sectional drawing (before peeling a transparent base material) of the hard coat film which concerns on embodiment Sectional drawing of hard coat film concerning embodiment (after peeling a transparent base material)

  As an example of the present invention, a hard coat film according to an embodiment will be described.

  In FIG. 1, the hard coat film 4 before peeling the transparent base material 1 is shown. In FIG. 2, the hard coat film 4 after peeling the transparent base material 1 is shown. The hard coat film 4 has a base material layer 2 and a hard coat layer 3 formed on at least one surface of the base material layer 2. The base material layer 2 is a composition containing at least an ionizing radiation curable oligomer having a molecular weight of 1000 or less and containing two functional groups represented by the general formula (I) in one molecule, and a photopolymerization initiator. The hard coat layer 3 is a hard coat composition containing an ultraviolet curable resin and a photopolymerization initiator. The hard coat film 4 is obtained by forming a laminate composed of the substrate layer 2 and the hard coat layer 3 on the transparent substrate 1 and then peeling the transparent substrate 1 from the laminate. The hard coat film 4 has a hardness of 4H or more in a pencil hardness test (4.9 N load) specified in JIS K5600-5-4 (1999).

  The hard coat film 4 of the present invention is applied to the transparent substrate 1 after applying and drying an ionizing radiation curable oligomer coating liquid containing two functional groups represented by the general formula (I) in one molecule, It hardens | cures by ionizing radiation, and after apply | coating and drying the coating liquid for hard-coat layer formation on it, it hardens | cures by ionizing radiation and completes by peeling the transparent base material 1. FIG.

  First, the transparent substrate 1 will be described. As the transparent substrate 1 of the present invention, in consideration of various properties such as peelability, transparency, impact resistance, heat resistance and durability, polyolefins such as polyethylene and polypropylene, polyethylene terephthalate, polyethylene naphthalate Those made of an organic polymer such as polyester and the like are used. In particular, polyethylene terephthalate is preferable because of good peelability.

  The thickness of the transparent substrate 1 is preferably in the range of 15 μm or more and 200 μm or less, and more preferably in the range of 20 μm or more and 80 μm or less.

  Then, the base material layer 2 is demonstrated. As a coating liquid for forming the base material layer 2 of the present invention, an ionizing radiation curable oligomer (ionizing radiation curable material) containing two functional groups represented by the general formula (I) of the above formula 1 in one molecule. ), A photopolymerization initiator, and an ionizing radiation curable oligomer coating solution containing at least a solvent.

  As the main component (ionizing radiation curable material) of this ionizing radiation curable oligomer coating solution, for example, Kyoeisha Chemical's epoxy ester M-600A, epoxy ester 40EM, epoxy ester 70PA, epoxy ester 200PA, epoxy ester 80FMA, epoxy An ester 3002M, an epoxy ester 3002A, an epoxy ester 3000MK, and an epoxy ester 3000A can be used.

  In addition, since the ionizing radiation curable material is cured by ultraviolet rays, a photopolymerization initiator is added. Any photopolymerization initiator may be used as long as it can generate radicals when irradiated with ultraviolet rays. I can do it. Moreover, the addition amount of the photopolymerization initiator is 0.1 part by weight to 10 parts by weight, preferably 1 part by weight to 7 parts by weight, and more preferably 1 part by weight to 100 parts by weight of the ionizing radiation curable material. 5 parts by weight.

  Furthermore, a solvent can be added to the ionizing radiation curable oligomer coating liquid as necessary. Solvents include aromatic hydrocarbons such as toluene, xylene, cyclohexane and cyclohexylbenzene, hydrocarbons such as n-hexane, dibutyl ether, dimethoxymethane, dimethoxyethane, diethoxyethane, propylene oxide, dioxane, dioxolane, and trioxane. , Ethers such as tetrahydrofuran, anisole and phenetole, and ketones such as methyl isobutyl ketone, methyl butyl ketone, acetone, methyl ethyl ketone, diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, and methylcyclohexanone , Ethyl formate, propyl formate, n-pentyl formate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, Suitable for coating from acid esters such as n-pentyl and γ-ptyrolactone, cellosolves such as methyl cellosolve, cellosolve, butyl cellosolve, cellosolve acetate, and alcohols such as methanol, ethanol, isopropyl alcohol, butanol Etc. are selected as appropriate.

  In addition, a surface adjusting agent, a refractive index adjusting agent, an adhesion improver, a curing agent and the like can be added to the coating liquid as additives.

  By sufficiently mixing the above materials, an ionizing radiation curable oligomer coating solution is completed.

  The base layer 2 is formed by a wet coating method, such as a dip coating method, a spin coating method, a flow coating method, a spray coating method, a roll coating method, a gravure roll coating method, an air doctor coating method, a blade coating method. , Wire doctor coating method, knife coating method, reverse coating method, transfer roll coating method, micro gravure coating method, kiss coating method, cast coating method, slot orifice coating method, calendar coating method, die coating method, etc. It can be formed by applying an ionizing radiation curable oligomer coating liquid to at least one surface of the material 1.

  Subsequently, the details of the hard coat layer 3 of the present invention will be described below.

  As the coating liquid used in the formation of the hard coat layer 3 of the present invention, a hard coat layer forming coating liquid containing at least an ultraviolet curable substance, a photopolymerization initiator, and a solvent is used. In addition, an ultraviolet curable substance means resin which has as a main component resin which hardens | cures through a crosslinking reaction by active ray irradiation like an ultraviolet-ray or an electron beam.

  Examples of the ultraviolet curable substance include photopolymerizable monomers and photopolymerizable prepolymers such as polyester acrylate, epoxy acrylate, urethane acrylate, and polyol acrylate. These ionizing radiation curable resins (ultraviolet curable substances) may be used alone or in combination of two or more.

  As the polyester acrylate, those easily formed by reacting a polyester polyol with a 2-hydroxy acrylate or 2-hydroxy acrylate monomer can be used.

  The epoxy acrylate is an acrylate obtained by opening an epoxy group of an epoxy resin and acrylated with acrylic acid, and one using an aromatic ring or an alicyclic epoxy is more preferably used.

  The ultraviolet polymerization initiator (photopolymerization initiator) used in the formation of the hard coat layer 3 of the present invention is a surface curing type polymerization initiator, and is an α-hydroxyketone having an absorption at a short wavelength, such as Irg184. DAROCUR 1173, Irg 2959, and α-aminoketone Irg 907 having a high molar extinction coefficient are preferably used. Further, as an internal curing photopolymerization initiator, an acylphosphine oxide having a high photobleaching effect, for example, Irg819, or an α-aminoketone having an absorption region in the h-line, for example, Irg369 is preferably used. .

  In addition to the above-mentioned ones, for example, acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, etc. Any initiator can be selected as appropriate.

  The amount of the ultraviolet polymerization initiator used is preferably in the range of 0.5 wt% to 15 wt% based on the total solid content of the photosensitive coloring composition (ultraviolet curable substance), and more than this range. At least, the film hardness tends to be low. In particular, when the amount is too large, the hard coat layer 3 may be colored. Moreover, an ultraviolet polymerization initiator consists of a combination of Irg184 and TPO or Irg184 and Irg819, for example, and these weight ratios are in the range of 70:30 to 30:70.

  Moreover, n-butylamine, triethylamine, poly-n-butylphosphine, etc. can be mixed and used as a photosensitizer.

  These resins and photopolymerization initiators can be dissolved in a solvent and adjusted to a solid content of 30 to 80% by weight, more preferably 40 to 60% by weight, and can be applied to a plastic substrate.

  The solvent used in the hard coat layer-forming coating solution of the present invention may be any solvent as long as it dissolves the resin and the photopolymerization initiator and provides good coating properties. In general, when a solvent having a low boiling point is used, drying after coating becomes faster, so it is more preferable to use a solvent having a high boiling point.

  Examples of the solvent used in the present invention include high boiling ketone solvents such as methyl isobutyl ketone and cyclohexanone, aromatic hydrocarbon solvents such as toluene and xylene, alcohol solvents such as 2-propanol, 1-butanol, cyclopentanol and diacetone alcohol. And ether alcohol solvents such as ethylene glycol monomethyl ether and propylene glycol monomethyl ether, and high-boiling ester solvents such as isobutyl acetate and butyl acetate.

  Among these organic solvents, high boiling ketone solvents, aromatic hydrocarbon solvents, alcohol solvents, and high boiling acetate solvents are preferably used.

  In the prepared paint, additives can be used for antifouling property, slipperiness imparting, defect prevention, and particle dispersibility improvement. Examples of the additive that can be used include polyether-modified polymethylalkylsiloxane, polyether-modified polydimethylsiloxane, fluorine-modified polymer, acrylic copolymer, polyester-modified acrylic-containing polydimethylsiloxane, and silicon-modified polyacryl. .

  Moreover, a well-known method can be used as a coating system. Specifically, bar coating, dip coating, spin coating, flow coating, spray coating, roll coating, gravure roll coating, air doctor coating, blade coating, wire doctor coating, knife coating Methods, reverse coating method, transfer roll coating method, micro gravure coating method, kiss coating method, cast coating method, slot orifice coating method, calendar coating method, die coating method and the like can be used.

The light source for curing the ultraviolet curable resin by a photo-curing reaction to form a cured film is not particularly limited as long as it is a light source that generates ultraviolet rays. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, an electrodeless discharge tube, or the like can be used. As the irradiation condition, the ultraviolet irradiation amount can be 100 to 800 mJ / cm ² .

  The hard coat layer 3 (cured resin layer) thus obtained can contain fine particles of inorganic or organic compounds for preventing blocking, imparting hardness, imparting antiglare properties, imparting antistatic performance, or adjusting the refractive index. .

  The inorganic fine particles used for the hard coat layer 3 include oxides such as silicon oxide, titanium oxide, aluminum oxide, zirconium oxide, magnesium oxide, tin oxide, and antimony pentoxide, and composites such as antimony-doped tin oxide and phosphorus-doped tin oxide. An oxide is mentioned. In addition, calcium carbonate, talc, clay, kaolin, calcium silicate, aluminum silicate, magnesium silicate, calcium phosphate and the like can also be used.

  The organic fine particles used in the hard coat layer 3 include polymethyl methacrylate resin powder, acrylic-styrene resin powder, polymethyl methacrylate resin powder, silicon resin powder, polystyrene powder, polycarbonate powder, melamine resin. Examples thereof include powder and polyolefin resin powder.

  The average particle size of these fine particle powders is preferably 5 nm to 20 μm, and more preferably 10 nm to 10 μm. These fine particles can also be used in combination of two or more.

  The hard coat film 4 obtained in the present invention has an antireflection performance, an antistatic performance, an antifouling performance, an antiglare performance, an electromagnetic wave shielding performance, an infrared absorption performance, an ultraviolet absorption performance on the hard coat layer 3 as necessary. A functional layer having color correction performance and the like is provided. Examples of these functional layers include an antireflection layer, an antistatic layer, an antifouling layer, an antiglare layer, an electromagnetic wave shielding layer, an infrared absorption layer, an ultraviolet absorption layer, and a color correction layer. The functional layer on the hard coat layer 3 is selected from these functional layers and may be a single layer or a plurality of layers. For example, the antireflection layer may be composed of a single low refractive index layer, or may be composed of a plurality of layers by repeating a low refractive index layer and a high refractive index layer. Further, the functional layer may have a plurality of functions as a single layer, such as an antireflection layer having antifouling performance. The functional film having the hard coat film 4 and the hard coat layer 3 formed on the transparent substrate 1 can be bonded to various display surfaces such as a liquid crystal display, a plasma display, and a CRT display. An excellent display can be provided.

  Examples of the low refractive index layer that is an antireflection layer include a low refractive index agent dispersed in a binder matrix. At this time, the kind of the low refractive index agent is not particularly limited, but a low refractive index material such as magnesium fluoride, hollow particles containing air, or a fluororesin can be used. These low refractive index agents are dispersed in a binder curable material such as a UV curable material or a metal alkoxide such as silicon alkoxide, and a solvent is added as required to form a coating solution. Coating is performed on the hard coat layer 3. And after apply | coating a coating liquid on the hard-coat layer 3, when using an ultraviolet curable material as a binder matrix material, by irradiating with an ultraviolet-ray, when using a metal alkoxide, by baking, A low refractive index layer can be formed, and an antireflection film can be obtained. As the UV curable material, the multifunctional monomer exemplified above can be used. At this time, a photopolymerization initiator can be blended. As a coating method, a coating method using a roll coater, a reverse roll coater, a gravure coater, a knife coater, a bar coater, or a slot die coater can be used. In view of cost, the antireflection layer is preferably composed of a single low refractive index layer rather than a plurality of layers by repeating a low refractive index layer and a high refractive index layer. Before forming the low refractive index layer, the hard coat layer 3 of the hard coat film 4 having high hardness is saponified with an alkaline solution for the purpose of improving the adhesion between the hard coat layer 3 and the antireflection layer. Processing can also be performed.

Examples of the present invention will be described below. However, the present invention is not limited to these examples. The performance of the hard coat film 4 was evaluated by performing an evaluation test using the following method.
The pencil hardness was evaluated according to JIS-K5400 (4.9N load).
The total light transmittance was measured according to JIS-K7105 using NDH-2000 manufactured by Nippon Denshoku.
In the interference fringe evaluation, a matte black paint was applied to one surface of the transparent substrate, and the hard coat layer 3 side was visually observed to evaluate the occurrence of interference fringes. The quality of the evaluation was determined in the following four stages.
◎: Interference fringes are difficult to see even under three-wavelength fluorescent lamps ○: Interference fringes are visible even under three-wavelength fluorescent lamps △: Interference fringes are visible even with ceiling light ×: Interference fringes are clearly visible even with ceiling light

<Example 1>
Transparent substrate: 75 μm polyethylene terephthalate substrate ionizing radiation curable oligomer coating solution:
Epoxy ester 3002A (Kyoeisha Chemical) 80 parts by weight Irgacure 184 (BASF) 5 parts by weight Methyl acetate 15 parts by weight Hard coat layer forming coating solution:
Urethane acrylate UA-306H (Kyoeisha Chemical) 19 parts by weight Acrylic monomer PE-3A (Kyoeisha Chemical) 13 parts by weight Irgacure 184 (BASF) 1.5 parts by weight
TPO (BASF) 1.5 parts by weight Methyl isobutyl ketone 65 parts by weight

A coating liquid obtained by stirring and mixing the above materials described in the column of ionizing radiation curable oligomer coating liquid is applied by a bar coating method so as to have a cured film thickness of 40 μm, and then dried and 200 mJ by a metal halide lamp. The base material layer 2 was formed by irradiating with / cm ² of ultraviolet rays. And the coating liquid obtained by stirring and mixing the above-mentioned materials described in the column of hard coating layer forming coating liquid is applied on the base material layer 2 so as to have a cured film thickness of 8 μm by the bar coating method. After drying, the hard coat layer 3 was formed by irradiating 400 mJ / cm ² of ultraviolet rays with a metal halide lamp. Thereafter, the 75 μm polyethylene terephthalate substrate (transparent substrate) was peeled off to produce a hard coat film 4.

  As a result of performing an evaluation test on the hard coat film 4 of Example 1, the pencil hardness is 4H, the total light transmittance is 96.4%, the interference fringes are excellent, the interference fringes are good, the surface hardness is high, and the transparency. It was confirmed that the hard coat film 4 was excellent.

<Example 2>
Transparent substrate: 75 μm polyethylene terephthalate substrate ionizing radiation curable oligomer coating solution:
Epoxy ester 3002A (Kyoeisha Chemical) 80 parts by weight Irgacure 184 (BASF) 5 parts by weight Methyl acetate 15 parts by weight Hard coat layer forming coating solution:
30 parts by weight of urethane acrylate UA-306H (Kyoeisha Chemical)
Acrylic monomer PE-3A (Kyoeisha Chemical) 20 parts by weight Irgacure 184 (BASF) 2.5 parts by weight
TPO (BASF) 2.5 parts by weight Methyl isobutyl ketone 45 parts by weight

A coating liquid obtained by stirring and mixing the above materials described in the column of ionizing radiation curable oligomer coating liquid is applied by a bar coating method so as to have a cured film thickness of 40 μm, and then dried and 200 mJ by a metal halide lamp. The base material layer 2 was formed by irradiating with / cm ² of ultraviolet rays. And the coating liquid obtained by stirring and mixing the above-mentioned materials described in the column of hard coating layer forming coating liquid is applied on the base material layer 2 so as to have a cured film thickness of 8 μm by the bar coating method. After drying, the hard coat layer 3 was formed by irradiating 400 mJ / cm ² of ultraviolet rays with a metal halide lamp. Thereafter, the 75 μm polyethylene terephthalate substrate was peeled off to produce a hard coat film 4.

  As a result of performing an evaluation test on the hard coat film 4 of Example 2, the pencil hardness is 4H, the total light transmittance is 96.2%, the interference fringes are excellent, the interference fringes are good, the surface hardness is high, and the transparency. It was confirmed that the hard coat film 4 was excellent.

<Example 3>
Transparent substrate: 75 μm polyethylene terephthalate substrate ionizing radiation curable oligomer coating solution:
Epoxy ester 3002A (Kyoeisha Chemical) 80 parts by weight Irgacure 184 (BASF) 5 parts by weight Methyl acetate 15 parts by weight Hard coat layer forming coating solution:
Urethane acrylate UA-306H (Kyoeisha Chemical) 41 parts by weight Acrylic monomer PE-3A (Kyoeisha Chemical) 27 parts by weight Irgacure 184 (BASF) 3.5 parts by weight
TPO (BASF) 3.5 parts by weight Methyl isobutyl ketone 25 parts by weight

A coating liquid obtained by stirring and mixing the above materials described in the column of ionizing radiation curable oligomer coating liquid is applied by a bar coating method so as to have a cured film thickness of 40 μm, and then dried and 200 mJ by a metal halide lamp. The base material layer 2 was formed by irradiating with / cm ² of ultraviolet rays. And the coating liquid obtained by stirring and mixing the above-mentioned materials described in the column of hard coating layer forming coating liquid is applied on the base material layer 2 so as to have a cured film thickness of 8 μm by the bar coating method. After drying, the hard coat layer 3 was formed by irradiating 400 mJ / cm ² of ultraviolet rays with a metal halide lamp. Thereafter, the 75 μm polyethylene terephthalate substrate was peeled off to produce a hard coat film 4.

  As a result of an evaluation test on the hard coat film 4 of Example 3, the pencil hardness is 4H, the total light transmittance is 96.5%, the interference fringes are excellent, the interference fringes are good, the surface hardness is high, and the transparency. It was confirmed that the hard coat film 4 was excellent.

<Comparative Example 1>
Transparent substrate: 40 μm triacetylcellulose substrate hard coat layer forming coating solution:
Urethane acrylate UA-306H (Kyoeisha Chemical) 19 parts by weight Acrylic monomer PE-3A (Kyoeisha Chemical) 13 parts by weight Irgacure 184 (BASF) 1.5 parts by weight
TPO (BASF) 1.5 parts by weight Methyl isobutyl ketone 65 parts by weight

A coating solution obtained by stirring and mixing the above materials described in the column for coating liquid for forming a hard coat layer was applied by a bar coating method so as to have a cured film thickness of 8 μm, then dried, and 400 mJ by a metal halide lamp. A hard coat layer was formed by irradiating UV light of / cm ² to produce a hard coat film.

  As a result of performing an evaluation test on the hard coat film of Comparative Example 1, the pencil hardness was 2H, the total light transmittance was 95.4%, and the interference fringes ◎, and the pencil hardness and the total light transmittance were deteriorated.

<Comparative example 2>
Transparent substrate: 40 μm triacetylcellulose substrate hard coat layer forming coating solution:
Urethane acrylate UA-306H (Kyoeisha Chemical) 30 parts by weight Acrylic monomer PE-3A (Kyoeisha Chemical) 20 parts by weight Irgacure 184 (BASF) 2.5 parts by weight
TPO (BASF) 2.5 parts by weight Methyl isobutyl ketone 45 parts by weight

A coating solution obtained by stirring and mixing the above materials described in the column for coating liquid for forming a hard coat layer was applied by a bar coating method so as to have a cured film thickness of 8 μm, then dried, and 400 mJ by a metal halide lamp. A hard coat layer was formed by irradiating UV light of / cm ² to produce a hard coat film.

  As a result of conducting an evaluation test on the hard coat film of Comparative Example 2, the pencil hardness was 3H, the total light transmittance was 95.3%, and the interference fringes ○, and the pencil hardness, the total light transmittance, and the interference fringes were deteriorated.

<Comparative Example 3>
Transparent substrate: 40 μm triacetylcellulose substrate hard coat layer forming coating solution:
Urethane acrylate UA-306H (Kyoeisha Chemical) 41 parts by weight Acrylic monomer PE-3A (Kyoeisha Chemical) 27 parts by weight Irgacure 184 (BASF) 3.5 parts by weight
TPO (BASF) 3.5 parts by weight Methyl isobutyl ketone 25 parts by weight

A coating solution obtained by stirring and mixing the above materials described in the column for coating liquid for forming a hard coat layer was applied by a bar coating method so as to have a cured film thickness of 8 μm, then dried, and 400 mJ by a metal halide lamp. A hard coat layer was formed by irradiating UV light of / cm ² to produce a hard coat film.

  As a result of performing an evaluation test on the hard coat film of Comparative Example 3, the pencil hardness was 4H, the total light transmittance was 95.6%, and the interference fringes were Δ. The total light transmittance and the interference fringes were deteriorated.

<Comparative Example 4>
Transparent substrate: 40 μm polyethylene terephthalate substrate Hard coat layer forming coating solution:
Urethane acrylate UA-306H (Kyoeisha Chemical) 19 parts by weight Acrylic monomer PE-3A (Kyoeisha Chemical) 13 parts by weight Irgacure 184 (BASF) 1.5 parts by weight
TPO (BASF) 1.5 parts by weight Methyl isobutyl ketone 65 parts by weight

A coating solution obtained by stirring and mixing the above materials described in the column for coating liquid for forming a hard coat layer was applied by a bar coating method so as to have a cured film thickness of 8 μm, then dried, and 400 mJ by a metal halide lamp. A hard coat layer was formed by irradiating UV light of / cm ² to produce a hard coat film.

  As a result of performing an evaluation test on the hard coat film of Comparative Example 4, the pencil hardness was 4H, the total light transmittance was 92.3%, and the interference fringes Δ, and the total light transmittance and the interference fringes were deteriorated.

<Comparative Example 5>
Transparent substrate: 40 μm polyethylene terephthalate substrate Hard coat layer forming coating solution:
Urethane acrylate UA-306H (Kyoeisha Chemical) 30 parts by weight Acrylic monomer PE-3A (Kyoeisha Chemical) 20 parts by weight Irgacure 184 (BASF) 2.5 parts by weight
TPO (BASF) 2.5 parts by weight Methyl isobutyl ketone 45 parts by weight

A coating solution obtained by stirring and mixing the above materials described in the column for coating liquid for forming a hard coat layer was applied by a bar coating method so as to have a cured film thickness of 8 μm, then dried, and 400 mJ by a metal halide lamp. A hard coat layer was formed by irradiating UV light of / cm ² to produce a hard coat film.

  As a result of performing an evaluation test on the hard coat film of Comparative Example 5, the pencil hardness was 4H, the total light transmittance was 92.3%, and the interference fringes were Δ. The total light transmittance and the interference fringes were deteriorated.

<Comparative Example 6>
Transparent substrate: 40 μm polyethylene terephthalate substrate Hard coat layer forming coating solution:
Urethane acrylate UA-306H (Kyoeisha Chemical) 41 parts by weight Acrylic monomer PE-3A (Kyoeisha Chemical) 27 parts by weight Irgacure 184 (BASF) 3.5 parts by weight
TPO (BASF) 3.5 parts by weight Methyl isobutyl ketone 25 parts by weight

A coating solution obtained by stirring and mixing the above materials described in the column for coating liquid for forming a hard coat layer was applied by a bar coating method so as to have a cured film thickness of 8 μm, then dried, and 400 mJ by a metal halide lamp. A hard coat layer was formed by irradiating UV light of / cm ² to produce a hard coat film.

  As a result of performing an evaluation test on the hard coat film of Comparative Example 6, the pencil hardness was 4H, the total light transmittance was 92.5%, and the interference fringes were Δ. The total light transmittance and the interference fringes were deteriorated.

  The evaluation results of Examples 1 to 3 and Comparative Examples 1 to 6 are summarized in Table 1 below. Table 1 is a performance comparison table of Examples and Comparative Examples.

  When Examples 1 to 3 and Comparative Examples 1 to 6 are compared, by using an ionizing radiation curable oligomer containing two functional groups represented by general formula (I) in one molecule in the base material layer 2 It can be seen that the surface hardness, permeability, and interference fringes are good.

  The present invention is useful for a hard coat film having a hard coat layer.

DESCRIPTION OF SYMBOLS 1 Transparent base material 2 Base material layer 3 Hard coat layer 4 Hard coat film

Claims (2)

A base material layer;
A hard coat layer formed on at least one side of the base material layer,
The base material layer comprises a cured film of a composition containing an ionizing radiation curable oligomer having a molecular weight of 1000 or less containing two functional groups represented by the general formula (I) in one molecule, and a photopolymerization initiator. ,
(In the formula, R ₁ represents hydrogen or a methyl group.)
The hard coat layer comprises a cured film of a hard coat composition containing an ultraviolet curable resin and a photopolymerization initiator ,
The hard coat film, wherein the ionizing radiation curable oligomer is a compound represented by the formula (II) .
  2. The hard coat film according to claim 1, wherein the hardness of a pencil hardness test (4.9 N load) specified in JIS K5600-5-4 (1999) is 4H or more.