JP6040659B2 - UV absorbing hard coat film - Google Patents

Description

  The present invention relates to an ultraviolet absorbing hard coat film provided with an ultraviolet absorbing hard coat layer.

  In recent years, in film decoration applications such as automobiles and building materials, film products have made remarkable progress due to their excellent processability and price, and light weight. Since these film products can provide various functions based on a base film, they are also attracting attention regarding functionality.

  For these film products, transparent substrate films such as polyethylene terephthalate (PET) are generally used. However, the physical properties such as surface hardness of these films are weak, and when they come into contact with hard materials, scratches occur and the appearance is impaired. There was a problem such as. Therefore, a method of laminating a hard coat layer on a transparent base film and imparting physical resistance such as surface hardness to the transparent base film has been conventionally performed (Patent Document 1).

On the other hand, these film products are often used in places exposed to sunlight (particularly ultraviolet rays). However, since the transparent substrate film and hard coat layer used in these film products are deteriorated by exposure to sunlight, the adhesion between the transparent substrate film and the hard coat layer is reduced, or the hard coat layer There has been a problem that the function assigned to is lost. Therefore, in order to impart resistance to sunlight, a weather-resistant polyester film in which a weather-resistant coat layer is laminated on the PET surface has been proposed (Patent Document 2). Moreover, in a hard coat film used for an electronic display or the like, deterioration due to ultraviolet rays is prevented by adding a triazine ultraviolet absorber to the hard coat layer (Patent Document 3). Further, for building materials, degradation by ultraviolet rays is prevented by adding a triazine-based ultraviolet absorber to the hard coat layer (Patent Document 4).

Japanese Patent No. 2003-184329 JP 2009-226745 A JP 2009-294329 A JP 2012-76354 A

  In patent document 1, the problem regarding physical tolerance, such as surface hardness, is eliminated by laminating | stacking a hard-coat layer on a transparent base film. However, the problem of deterioration due to sunlight has not been solved.

  On the other hand, Patent Document 2 improves the problem of deterioration due to sunlight, but there is no description regarding physical resistance, and it cannot be said that this problem has been solved. Patent Document 3 particularly relates to an electronic display, which improves the problem of deterioration due to sunlight. However, conventional triazine-based ultraviolet absorbers are not always satisfactory in terms of performance. Therefore, when it is going to obtain sufficient weather resistance, there exists a problem that the addition amount of a ultraviolet absorber will become excess and a ultraviolet absorber will bleed. In addition, in order to secure the total amount of the UV absorber, if the hard coat layer is excessively thick, the shrinkage of the UV curable resin, which is the material of the hard coat layer, increases, so the film having the hard coat layer However, there is a problem that the workability deteriorates. Although Patent Document 4 selects an appropriate UV absorber for weather resistance, a primer layer is provided between the two in order to maintain adhesion between the base film and the hard coat layer, which increases the number of processing steps. There is concern over the cost increase.

  Accordingly, the present invention solves the above-mentioned problems, and the object thereof is a hard coat film obtained by laminating a hard coat layer directly on a transparent substrate film, and an ultraviolet ray is applied to the hard coat layer coating liquid. By adding an ultraviolet absorber with a specific structure that has a high light absorption capacity in the region, it is possible to reduce the amount of ultraviolet absorber added and thin the hard coat layer, thus sufficiently preventing curling deterioration An object of the present invention is to provide a UV-absorbing hard coat film having excellent weather resistance.

（２）前記紫外線吸収性ハードコート層塗布液が、下記一般式（２）で表される４級アンモニウム塩基を有する化合物（ｅ−１）と、１つのエチレン不飽和基を有する化合物（ｅ−２）とをラジカル共重合して得られる（Ｅ）４級アンモニウム塩系共重合体を含むことを特徴とする（１）に記載の紫外線吸収性ハードコートフィルム。
ＣＨ_２＝Ｃ（Ｒ^１）ＣＯＺ（ＣＨ_２）_ｋＮ^＋（Ｒ^２）_３・Ｘ⁻ ・・・（２）
（式中、Ｒ^１はＨまたはＣＨ_３、Ｒ^２はそれぞれ独立して炭素数が１〜４の炭化水素基、Ｚは酸素原子またはＮＨ基、ｋは１〜１０の整数、Ｘ⁻は１価のアニオンを表す。）
（３）前記紫外線吸収性ハードコート層の上に、該紫外線吸収性ハードコート層よりも屈折率の低い低屈折率層が設けられていることを特徴とする、（１）または（２）に記載の紫外線吸収性ハードコートフィルム。
（４）前記透明基材フィルムの他方面に粘着層が設けられていることを特徴とする（１）ないし（３）のいずれかに記載の紫外線吸収性ハードコートフィルム。
なお、本発明において数値範囲を示す「○○〜××」とは、その下限（○○）及び上限（××）の数値を含む意味である。したがって、正確に表せば「○○以上××以下」となる。 That is, the ultraviolet absorbing hard coat film of the present invention is as follows.
(1) An ultraviolet-absorbing hard coat film in which an ultraviolet-absorbing hard coat layer is formed on one surface of a transparent substrate film, wherein the ultraviolet-absorbing hard coat layer is (A) 100 mass of an ultraviolet curable resin. Parts, (B) 1 to 20 parts by weight of an ultraviolet absorber represented by the following general formula (1) that absorbs light having a wavelength of 300 to 350 nm, and (C) 0.1 to 10 parts by weight of a photopolymerization initiator. And (D) a UV absorbing hard coat layer coating liquid containing 0.001 to 20 parts by mass of a surface conditioner, and UV curing, wherein the UV absorbing hard coat layer coating liquid is a layer having a thickness of 0.5 to 10 μm Hard coat film.

(2) The ultraviolet-absorbing hard coat layer coating solution comprises a compound (e-1) having a quaternary ammonium base represented by the following general formula (2) and a compound having one ethylenically unsaturated group (e- And (E) a quaternary ammonium salt copolymer obtained by radical copolymerization with (2). The ultraviolet absorbing hard coat film according to (1).
CH ₂ = C (R ¹ ) COZ (CH ₂ ) _k N ⁺ (R ² ) ₃ · X ⁻ (2)
(In the formula, R ¹ is H or CH ₃ , R ² is independently a hydrocarbon group having 1 to 4 carbon atoms, Z is an oxygen atom or NH group, k is an integer of 1 to 10, and X ⁻ is 1) Represents a valent anion.)
(3) (1) or (2), wherein a low refractive index layer having a lower refractive index than that of the ultraviolet absorbing hard coat layer is provided on the ultraviolet absorbing hard coat layer. The ultraviolet-absorbing hard coat film as described.
(4) The ultraviolet absorbing hard coat film according to any one of (1) to (3), wherein an adhesive layer is provided on the other surface of the transparent substrate film.
In the present invention, “OO to XX” indicating a numerical range means that the numerical values of the lower limit (OO) and the upper limit (XX) are included. Therefore, if it is expressed accurately, it will be “XX or more and XX or less”.

  According to the present invention, physical resistance and weather resistance (ultraviolet absorption) can be imparted by laminating a hard coat layer containing an ultraviolet absorber having a high light absorption ability in the ultraviolet region on the transparent substrate film, It is possible to provide an ultraviolet-absorbing hard coat film that has excellent processability and can withstand long-term use without lowering the adhesion between the transparent base film and the hard coat layer even in an environment exposed to sunlight.

  As the ultraviolet absorber, a hydroxyphenyltriazine-based ultraviolet absorber having a specific structure represented by the general formula (1) is used. Since the ultraviolet absorbent has a high light absorption capability for light on the short wavelength side (ultraviolet region), it can efficiently absorb ultraviolet rays even when added in a small amount. Therefore, the addition amount of the ultraviolet absorber can be reduced, and the film thickness of the hard coat layer can be reduced. As a result, it is possible to prevent deterioration of curling properties and the like and to obtain a hard coat film having good processability and weather resistance. Moreover, in this invention, since a hard-coat layer is laminated | stacked directly on a transparent base film, the primer layer for improving both adhesiveness is unnecessary, and the increase in a process process can be prevented.

  The ultraviolet absorbing hard coat film of the present invention is applied to automobiles and building materials, and at least an ultraviolet absorbing hard coat layer is formed on one surface of the transparent substrate film.

<Transparent substrate film>
The transparent substrate film used for the ultraviolet absorbing hard coat film is not particularly limited as long as it has transparency. Examples of the material for forming such a transparent substrate film include polyesters such as polyethylene terephthalate (PET), polyarylate, triacetyl cellulose (TAC), and polyether sulfone. Among these, a polyester film, particularly a polyethylene terephthalate film is preferable in terms of ease of molding.

  Although the thickness of a transparent base film is not specifically limited, Generally, it is 25-400 micrometers, Preferably it is 50-200 micrometers. When the thickness of the transparent substrate film is thinner than 25 μm or thicker than 400 μm, the handleability during the production and use of the UV-absorbing hard coat film is lowered. In addition, various additives may contain in the transparent base film. Examples of such additives include ultraviolet absorbers, antistatic agents, stabilizers, plasticizers, lubricants, flame retardants, and the like.

<Ultraviolet absorbing hard coat layer>
The ultraviolet absorbing hard coat layer comprises (A) an ultraviolet curable resin, (B) a hydroxyphenyltriazine-based ultraviolet absorber represented by the general formula (1), (C) a photopolymerization initiator, and (D ) A layer obtained by UV-curing a UV-absorbing hard coat layer coating solution containing a surface conditioning agent. The ultraviolet-absorbing hard coat layer is formed by directly applying an ultraviolet-absorbing hard coat layer coating solution containing each of the above components to a transparent substrate film, and then irradiating with ultraviolet rays to cure.

  The thickness of the ultraviolet absorbing hard coat layer is 0.5 to 10 μm, preferably 1 to 6 μm. If the thickness of the UV-absorbing hard coat layer is less than 0.5 μm, the content of the UV-absorbing hard coat layer is also limited, so the UV-absorbing agent in the resulting UV-absorbing hard coat layer is limited. The amount of UV is relatively small, and a sufficient ultraviolet absorption effect cannot be obtained. On the other hand, if it exceeds 10 μm, curling at the time of curing the ultraviolet absorbing hard coat layer cannot be reduced.

  The ultraviolet-absorbing hard coat layer may contain an antistatic agent for the purpose of preventing adhesion of foreign matters such as dust generated during processing or actual use. Examples of such an antistatic agent include (E) a quaternary ammonium salt copolymer.

  Further, the refractive index of the ultraviolet absorbing hard coat layer may be about 1.45 to 1.70, and the ultraviolet absorbing hard coat layer has a refractive index for adjusting the refractive index of the ultraviolet absorbing hard coat layer. If necessary, a refractive index adjusting agent such as a metal oxide may be contained. The metal oxide used for the refractive index adjustment is not particularly limited as long as it is added to the ultraviolet absorbing hard coat layer coating solution for the purpose of increasing the refractive index. Examples of such metal oxides include zirconium oxide, zinc oxide, titanium oxide, cerium oxide, tin oxide, aluminum oxide, silane oxide, and indium tin oxide.

  The method for forming the ultraviolet absorbing hard coat layer on the transparent substrate film is not particularly limited as long as the ultraviolet absorbing hard coat layer coating solution is directly applied by a wet coating method and then irradiated with ultraviolet rays. As a coating method, for example, a conventionally known coating method such as a gravure coating method, a spin coating method, or a die coating method can be employed.

<(A) UV curable resin>
As the ultraviolet curable resin for forming the ultraviolet absorbing hard coat layer, any known resin that has been conventionally used in this type of hard coat film and that undergoes a curing reaction when irradiated with ultraviolet rays can be used. The type is not particularly limited. Examples of such a resin include monofunctional (meth) acrylate, polyfunctional (meth) acrylate, epoxy resin, urethane resin, and silicon resin. In the present specification, (meth) acrylate means a generic name including both acrylate and methacrylate. The description of (meth) acrylic acid, (meth) acrylic, and (meth) acryloyl is the same.

<(B) UV absorber>
The ultraviolet absorber absorbs light having a wavelength of 300 to 350 nm, and is represented by [2- (2-hydroxy-4- [1-octyloxycarbonylethoxy] phenyl) -4,6 represented by the following general formula (1). -Bis (4-phenylphenyl) -1,3,5-triazine].

  (B) Content of an ultraviolet absorber is 1-20 mass parts with respect to 100 mass parts of (A) ultraviolet curable resin, and 5-20 mass parts is more preferable. When the content of the UV absorber is more than 20 parts by mass, the UV-absorbing hard coat layer coating liquid tends to be less curable by UV rays, and the UV-absorbing hard coat film has a visible light transmittance. There is also a risk of decline. On the other hand, when the amount is less than 1 part by mass, the ultraviolet absorbing property of the ultraviolet absorbing hard coat film cannot be sufficiently exhibited.

  The ultraviolet absorber that absorbs light having a wavelength of 300 to 350 nm and also absorbs light of other wavelengths as long as a predetermined amount of the ultraviolet absorber represented by the general formula (1) is contained. Can be used together. Moreover, you may use together stabilizers, such as an inorganic type ultraviolet absorber, a hindered amine light stabilizer (HALS), and antioxidant.

  A conventionally well-known thing can be used as an inorganic type ultraviolet absorber. Examples thereof include cerium oxide, zinc oxide, and titanium oxide.

  Conventionally known hindered amine light stabilizers can be used. For example, decanedioic acid bis (2,2,6,6-tetramethyl-1- (octyloxy) -4-piperidinyl) ester 1,1-dimethylethyl hydroperoxide and the reaction product of octane, bis (1,2, 2,6,6-pentamethyl-4-piperidyl) sebacate and methyl 1,2,2,6,6-pentamethyl-4-piperidylsebacate, 2,4-bis [N-butyl-N- (1- Cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl) amino] -6- (2-hydroxyethylamine) -1,3,5-triazine) and the like.

<(C) Photopolymerization initiator>
The photopolymerization initiator contained in the UV-absorbing hard coat layer coating solution is not particularly limited as long as the polymerization reaction can be initiated by UV rays, and absorbs light having a wavelength of 220 to 400 nm. It is more preferable that the maximum absorption wavelength is not in the range of 300 to 350 nm. When the wavelength of light used for curing exceeds 400 nm, there is a possibility that the expression of photopolymerization initiating ability is insufficient. If the wavelength of light is less than 220 nm, ozone is likely to be generated, which is not preferable. Moreover, when the maximum absorption wavelength of a photoinitiator exists in the range of 300-350 nm, an ultraviolet absorber will be absorbed by an ultraviolet absorber and there exists a possibility that the photoinitiator initiating ability of a photoinitiator may not fully express.

  Examples of the photopolymerization initiator that absorbs light having a wavelength of 220 to 400 nm include 1-hydroxy-cyclohexyl-phenyl-ketone, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2-methyl-1 -[4- (methylthio) phenyl] -2-morpholinopropan-1-one and the like. Of these, 1-hydroxy-cyclohexyl-phenyl-ketone is preferred.

  (C) Content of a photoinitiator is 0.1-10 mass parts with respect to 100 mass parts of (A) ultraviolet curable resin. When the content of the photopolymerization initiator is less than 0.1 parts by mass, the polymerization and curing of the UV-absorbing hard coat layer is insufficient, and when it exceeds 10 parts by mass, the light not used for initiating the photopolymerization is used. The polymerization initiator may remain in the UV-absorbing hard coat layer on which the polymerization initiator is formed, and there is a possibility that adverse effects such as a decrease in visible light transmittance of the UV-absorbing hard coat film may occur.

<(D) Surface conditioner>
The surface conditioner is used for the purpose of imparting slipperiness to the surface of the ultraviolet absorbing hard coat layer. The type of the surface conditioner is not particularly limited. For example, polyether-modified polydimethylsiloxane having an acrylic group, polyether-modified dimethylsiloxane, polyester-modified dimethylsiloxane having an acrylic group, polyether-modified polydimethylsiloxane, polyester Examples thereof include modified polydimethylsiloxane and aralkyl-modified polymethylalkylsiloxane. Among these, polyether-modified polydimethylsiloxane having an acrylic group is preferable from the viewpoint of slipperiness.

  (D) Content of a surface conditioning agent is 0.001-20 mass parts with respect to 100 mass parts of (A) ultraviolet curable resin. When the content of the surface conditioning agent is less than 0.001 part by mass, the surface slipperiness cannot be sufficiently imparted and the physical resistance is lowered. When the content of the surface conditioner is 20 parts by mass or more, the transparent substrate film repels the UV-absorbing hard coat layer coating solution when the UV-absorbing hard coat layer coating solution is applied to the transparent substrate film. As a result, the UV-absorbing hard coat layer cannot be formed uniformly.

<(E) Quaternary ammonium salt copolymer>
(E) A quaternary ammonium salt copolymer can also be used to impart antistatic ability to the ultraviolet absorbing hard coat layer. The quaternary ammonium salt copolymer comprises a compound (e-1) having a quaternary ammonium base represented by the following general formula (2) and a compound (e-2) having one ethylenically unsaturated group. Ingredients.
CH ₂ = C (R ¹ ) COZ (CH ₂ ) _k N ⁺ (R ² ) ₃ · X ⁻ (2)
(In the formula, R ¹ is H or CH ₃ , R ² is independently a hydrocarbon group having 1 to 4 carbon atoms, Z is an oxygen atom or NH group, k is an integer of 1 to 10, and X ⁻ is 1) Represents a valent anion.)

  (E) The amount of the quaternary ammonium salt copolymer used is preferably 1 to 20 parts by weight and more preferably 3 to 10 parts by weight with respect to 100 parts by weight of the (A) ultraviolet curable resin. If it is less than 1 part by weight, sufficient antistatic performance cannot be obtained, and if it exceeds 20 parts by weight, the scratch resistance of the ultraviolet-absorbing hard coat layer formed is lowered.

<Compound (e-1) having quaternary ammonium base>
The compound (e-1) having a quaternary ammonium base is not particularly limited as long as it is a (meth) acrylic compound represented by the general formula (2) and containing a quaternary ammonium salt in its structure. Examples of such compounds include (meth) acrylates and (meth) acrylamides having an amino group.

As the hydrocarbon group having 1 to 4 carbon atoms which is R ² in the general formula (2), a substituted or unsubstituted hydrocarbon group can be used. When R ^{2 has} a carbon number greater than 5, the resulting (E) quaternary ammonium salt copolymer is increased in hydrophobicity, and as a result, (E) an ultraviolet absorptivity containing the quaternary ammonium salt copolymer. There are cases where the hygroscopicity of the hard coat layer is lowered and good antistatic performance cannot be obtained.

R ² in the general formula (2) is preferably an unsubstituted hydrocarbon group, and more preferably an unsubstituted alkyl group. As the unsubstituted alkyl group, any having or not having a branch can be used. As the unsubstituted alkyl group, an alkyl group having 1 to 3 carbon atoms is preferable, and an alkyl group having a methyl group or an ethyl group is preferable in that it is easily available.

  Examples of (meth) acrylates having an amino group for forming a compound (e-1) in which Z in the general formula (2) has a quaternary ammonium base having an oxygen atom include dimethylaminoethyl (meth) acrylate chloride Methyl quaternary salts, dimethylaminopropyl (meth) acrylate methyl chloride quaternary salts, and the like.

  Examples of (meth) acrylamides having an amino group for forming a compound (e-1) in which Z in the general formula (2) has an NH group quaternary ammonium base include dimethylaminoethyl (meth) acrylamide chloride Methyl quaternary salts, dimethylaminopropyl (meth) acrylamide methyl chloride quaternary salts, and the like.

<Compound (e-2) having one ethylenically unsaturated group>
The compound (e-2) having one ethylenically unsaturated group is not particularly limited as long as it is a monomer containing one ethylenically unsaturated group. Examples of such compounds include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, and hydroxyethyl. Various (meth) acrylates such as (meth) acrylate and benzyl (meth) acrylate are exemplified. Two or more kinds of compounds (e-2) may be used in combination.

  (E) A quaternary ammonium salt copolymer can be obtained by radical copolymerization of the compounds (e-1) and (e-2). The amount of each of the compounds (e-1) and (e-2) used is 30 to 70 from the viewpoint of antistatic performance in the total amount of 100 parts by mass of the quaternary ammonium salt copolymer. The amount of the compound (e-2) is preferably 70 to 30 parts by mass for the purpose of adjusting the antistatic property and solubility of the produced (E) quaternary ammonium salt copolymer. preferable.

<Low refractive index layer>
The ultraviolet-absorbing hard coat film of the present invention preferably includes a low refractive index layer on the surface in order to prevent reflection or reflection of external light such as sunlight or fluorescent lamps. The low refractive index layer is a layer having a refractive index lower than that of the ultraviolet absorbing hard coat layer, and is provided on the ultraviolet absorbing hard coat layer (on the surface side).

  As a material for forming the low refractive index layer, if the refractive index is in the range of 1.20 to 1.50 and is lower than the refractive index of the ultraviolet absorbing hard coat layer, this kind of hard coat film has a low refractive index. A known material for forming the layer can be used. For example, a binder resin added with low refractive index inorganic fine particles such as hollow silica or magnesium fluoride that lowers the refractive index, or a fluorine-based resin can be used. As the binder resin, the same (meth) acrylate as the (A) ultraviolet curable resin for forming the ultraviolet absorbing hard coat layer can be used. The low refractive index layer can be formed by coating and curing a low refractive index layer coating solution on the ultraviolet absorbing hard coat layer in the same manner as the ultraviolet absorbing hard coat layer. In addition, this low refractive index layer may have other functions as long as the function is not impaired, and an additive or the like is added to provide one type of functions such as antistatic property, antifouling property, slipperiness, and ultraviolet absorption. Or 2 or more types can be provided.

<Adhesive layer>
The ultraviolet-absorbing hard coat film of the present invention preferably has an adhesive layer on the surface opposite to the surface on which the ultraviolet-absorbing hard coat layer is laminated in order to impart an adhesive function to the object to be bonded. The adhesive layer is provided on the other side of the transparent substrate film. The material for forming the pressure-sensitive adhesive layer is not particularly limited, and examples thereof include pressure-sensitive adhesives such as acrylic pressure-sensitive adhesives, silicone pressure-sensitive adhesives, and urethane pressure-sensitive adhesives. preferable.

  The method for forming the adhesive layer is not particularly limited, and a conventionally known method for obtaining a cured film by heat curing, ultraviolet curing, electron beam curing or the like after forming a coating film by a wet coating method can be used. The adhesive layer may have other functions as long as the functions are not impaired. For example, a dye or an additive may be added to block light in a specific wavelength range, improve contrast, correct color tone, etc. 1 type or 2 types or more can be provided.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples and comparative examples, but the present invention is not limited to these.

(Preparation of quaternary ammonium salt copolymer)
(E) Quaternary ammonium salt copolymers (E1 to E4) were obtained by copolymerizing (e-1) and (e-2) as shown in Table 1 below. The specific materials shown in Table 1 are as follows.
α1: dimethylaminoethyl acrylate methyl chloride quaternary general formula (1): R ¹ = CH ₃ , R ² = CH ₃ , Z = O, k = 2, X ⁻ = Cl ⁻
α2: dimethylaminopropylacrylamide methyl chloride quaternary general formula (1): R ¹ = H, R ² = CH ₃ , Z = NH group, k = 3, X ⁻ = Cl ⁻
β1: Butyl methacrylate β2: Benzyl methacrylate

(Preparation of UV-absorbing hard coat layer coating solution)
The ultraviolet-absorbing hard coat layer coating solution comprises (A) an ultraviolet curable resin, (B) an ultraviolet absorber of the above general formula (1), (C) a photopolymerization initiator, and (D) a surface conditioner. (E) A quaternary ammonium salt copolymer is mixed as shown in Table 2 below, and isopropyl alcohol (IPA) is mixed so that the solid content concentration is 40% by mass. A coating layer coating solution was obtained. The specific materials shown in Table 2 are as follows.
A1: DPHA (dipentaerythritol hexaacrylate)
B1: Product name manufactured by BASF Japan Ltd .: Tinuvin 479 [2- (2-hydroxy-4- [1-octyloxycarbonylethoxy] phenyl) -4,6-bis (4-phenylphenyl) -1,3 5-triazine]
B2: Product name manufactured by BASF Japan Ltd .: Tinuvin 123 [bis (2,2,6,6-tetramethyl-1- (octyloxy) -4-piperidinyl) ester 1,1-dimethylethyl hydroperoxide of decanedioic acid And the reaction product of octane)
C1: Product name manufactured by BASF Japan Ltd .: Irgacure 184
C2: Product name manufactured by BASF Japan Ltd .: Irgacure 907
D1: Polyether-modified polydimethylsiloxane having an acrylic group (Product name: BYK3500, manufactured by BYK Japan)
D2: Polyether-modified polydimethylsiloxane (product name: BYK3510 manufactured by Big Chemie Japan Co., Ltd.)

(Preparation of low refractive index layer coating solution γ1)
The low refractive index layer coating solution γ1 is composed of 60 parts by mass of hollow silica fine particles having a particle size of 60 nm, 40 parts by mass of dipentaerythritol hexaacrylate (DPHA), a photopolymerization initiator [product name: Irgacure manufactured by BASF Japan Ltd. 907] and 2 parts by mass were obtained by mixing isopropyl alcohol (IPA) so that the solid content concentration was 5% by mass.

(Preparation of adhesive layer coating solution δ1)
94.6 parts by mass of n-butyl acrylate, 4.4 parts by mass of acrylic acid, 1 part by mass of 2-hydroxyethyl methacrylate, 0.4 parts by mass of azobisisobutyronitrile, 90 parts by mass of ethyl acetate, 60 parts by mass of toluene The mixture was mixed, and the mixture was heated to 65 ° C. under a nitrogen atmosphere to conduct a polymerization reaction for 10 hours to prepare an acrylic resin composition. By adding 1 part by mass of Coronate L [polyisocyanate manufactured by Nippon Polyurethane Co., Ltd.] to 99 parts by mass of this acrylic resin composition, and adding ethyl acetate so that the solid content concentration is 20% by mass, the solid content of the adhesive resin composition is obtained. An adhesive layer coating solution δ1 having a partial concentration of 20% by mass was obtained.

(Preparation of UV-absorbing hard coat film)
<Examples 1-1 to 1-12>
On one surface of the polyethylene terephthalate film, the UV-absorbing hard coat layer coating solution for each example described in Table 2 was applied by a gravure coating method so that the dry film thickness was 0.5, 1 or 10 μm, After drying, UV-absorbing hard coat films of Examples 1-1 to 1-12 were produced by irradiating and curing ultraviolet rays at an output of 400 mJ / cm ^{2 in} a nitrogen atmosphere [Table 2].
<Examples 2-1 to 2-6>
The UV absorbing hard coat layer coating solution for each example, in which (E) a quaternary ammonium salt copolymer described in Table 3 was added to one surface of a polyethylene terephthalate film, was dried by gravure coating method. Is dried and then cured by irradiating with an ultraviolet ray at an output of 400 mJ / cm ² under a nitrogen atmosphere, thereby curing the ultraviolet absorbing hard coat film of Examples 2-1 to 2-6. It produced [Table 3].
<Examples 3-1 and 3-2>
On the ultraviolet absorbing hard coat layer prepared in Examples 1-1 and 2-1, the low refractive index layer coating liquid γ1 has an optical film thickness after curing of kλ / 4 (k: 1, λ: 550 nm). The UV-absorbing hard coat films of Examples 3-1 and 3-2 were applied by a gravure coating method, dried, and then cured by irradiation with 400 mJ / cm ² of UV in a nitrogen atmosphere. It produced [Table 3].
<Examples 4-1 to 4-4>
The adhesive layer coating solution δ1 was applied onto a PET separate film using an auto applicator so that the thickness after drying was 25 μm, dried at 90 ° C. for 2 minutes, and then Examples 1-1, 3-1, and 2 were used. -1 and 3-2, using the UV-absorbing hard coat layer film formed on the other surface of the polyethylene terephthalate film opposite to the surface on which the UV-absorbing hard coat layer was formed, and bonding at 30 ° C. The ultraviolet-absorbing hard coat film of Examples 4-1 to 4-4 was produced by storing for 5 days [Table 3].

<Comparative Example 1>
An ultraviolet-absorbing hard coat film was produced in the same manner as in Example 1-1 except that (B) the ultraviolet absorbent was removed from the ultraviolet-absorbing hard coat layer coating solution.

<Comparative example 2>
An ultraviolet absorbing hard coat film was prepared in the same manner as in Example 1-1 except that the film thickness of the ultraviolet absorbing hard coat layer was changed to 0.1 μm.

<Comparative Example 3>
An ultraviolet absorbing hard coat film was prepared in the same manner as in Example 1-1 except that the film thickness of the ultraviolet absorbing hard coat layer was changed to 15 μm.

<Comparative example 4>
An ultraviolet-absorbing hard coat film was prepared in the same manner as in Example 1-1 except that (D) the surface conditioner was removed from the ultraviolet-absorbing hard coat layer coating solution.

  In the obtained UV-absorbing hard coat films of each Example and Comparative Example, the surface hardness, scratch resistance, adhesion after the weather resistance test, curling property, surface resistivity, luminous reflectance, and adhesion were evaluated. . The results are also shown in Tables 2 and 3. The measurement method for each item is as follows.

(I) Surface hardness Pencil hardness was measured according to JIS K5600-5-4 using a pencil hardness tester manufactured by Yasuda Seiki Co., Ltd.

(II) Scratch resistance The surface of the UV-absorbing hard coat film was fixed with # 0000 steel wool at the tip of an eraser abrasion tester manufactured by Honko Seisakusho Co., Ltd. and a load of 2.5 N (250 gf) was applied. The scratches on the surface after reciprocating the top 10 times were visually observed and evaluated according to the following 6 grades A to E.
A: No scratch, A ': 1-3 scratches, B: 4-10 scratches, C: 11-20 scratches, D: 21-30 scratches, E: 31 or more

(III) Weather resistance test I
<Super Xenon test>
Using a Super Xenon Weather Meter SX75 (manufactured by Suga Test Instruments Co., Ltd.), the test was conducted for 100 hours under the test conditions of an irradiation illuminance of 180 W / m ² , an irradiation light wavelength of 300 to 400 nm, and a BPT temperature of 63 ± 1 ° C. In accordance with JIS D0202-1998, a cross-cut peeling tape test was conducted. Using cellophane tape [Nichiban Co., Ltd., CT24], it was peeled off after adhering to the UV-absorbing hard coat layer of the UV-absorbing hard coat film or the low refractive index layer. The weather resistance was determined by adhesion, and the number of squares that did not peel out of 100 squares was expressed as OO / 100. For example, it was expressed as 100/100 when not peeling at all, and 0/100 when peeling completely.

(IV) Weather resistance test II
<Sunshine weather meter test>
Using a sunshine weather meter S80 (manufactured by Suga Test Instruments Co., Ltd.), irradiation illuminance (255 W / m ² ), wavelength of irradiated light 300 to 400 nm, BP temperature 63 ± 1 ° C., 60 minutes of 12-minute rainfall test conditions A 500-hour test was conducted, and after the test, a cross-cut peeling tape test conducted in the weather resistance test I was conducted.

(V) Curling test An ultraviolet-absorbing hard coat film having a size of 10 cm × 10 cm was prepared, and the curl heights at the four corners when placed on a horizontal surface were measured and judged according to the following criteria.
○: Curl height is less than 20 mm Δ: Curl height is 20 mm or more and less than 50 mm ×: Curl height is 50 mm or more

(VI) Surface resistivity Based on JISK6911-1995, it measured using the digital insulation meter [Toa DKK Co., Ltd. make, SM-8220].

(VII) Visibility reflectance In order to remove the back surface reflection of the measurement surface, an ultraviolet absorbing hard coat film whose surface is roughened with sandpaper and painted with a black paint is a spectrophotometer [trade name: manufactured by JASCO Corporation. U-best 560], 5 ° and −5 ° regular reflection spectra of light wavelengths of 380 nm to 780 nm were measured. Using the obtained spectral reflectance of 380 nm to 780 nm and the relative spectral distribution of the CIE standard illuminant D65, the tristimulus value Y of the object color due to reflection in the XYZ color system assumed in JIS Z8701 is obtained as the luminous reflectance. (%).

  From the results of Table 2, the ultraviolet-absorbing hard coat film of each Example had physical resistance and good adhesion after the weather resistance test. Further, the curling property was also good. On the other hand, since the ultraviolet absorbent hard coat film of Comparative Example 1 did not contain (B) the ultraviolet absorbent in the ultraviolet absorbent hard coat layer, the adhesion after the weather resistance test was remarkably deteriorated. The ultraviolet-absorbing hard coat film of Comparative Example 2 is deteriorated by ultraviolet rays of the ultraviolet-absorbing hard coat film due to a decrease in the content of the ultraviolet absorbent (B) accompanying the reduction of the film thickness of the ultraviolet-absorbing hard coat layer. It was not possible to sufficiently suppress the adhesion after the weather resistance test. In the ultraviolet absorbing hard coat film of Comparative Example 3, the curling property was deteriorated because the ultraviolet absorbing hard coat layer was too thick. In the ultraviolet absorbing hard coat film of Comparative Example 4, since (D) the surface conditioner was not added, the surface slipperiness was lowered and the physical resistance was lowered.

  From the results of Table 3, in Examples 2-1 to 2-6, 3-2, 4-3, and 4-4, the ultraviolet absorbing hard coat layer is an antistatic agent (E) quaternary ammonium salt-based copolymer. Since it contains a polymer, antistatic ability was imparted. In Examples 3-1, 3-2, 4-2, and 4-4, since the low refractive index layer is laminated, the visibility reflectance can be lowered, and the low refractive index layer is laminated. However, it was confirmed that the curling property was not affected. Furthermore, in Examples 4-1 to 4-4, adhesiveness could be obtained because the adhesive layer was laminated.

Claims (4)

An ultraviolet-absorbing hard coat film in which an ultraviolet-absorbing hard coat layer is formed on one side of the transparent substrate film,
The ultraviolet absorbing hard coat layer is
(A) 100 parts by mass of dipentaerythritol hexaacrylate,
(B) 1 to 20 parts by mass of an ultraviolet absorber represented by the following general formula (1) that absorbs light having a wavelength of 300 to 350 nm;
(C) 0.1-10 parts by mass of a photopolymerization initiator,
(D) 0.001 to 20 parts by mass of a polyether-modified polydimethylsiloxane ;
An ultraviolet-absorbing hard coat film, which is a layer having a thickness of 0.5 to 10 μm obtained by ultraviolet-curing an ultraviolet-absorbing hard coat layer coating solution containing

The ultraviolet absorbing hard coat layer coating solution is a compound (e-1) having a quaternary ammonium base represented by the following general formula (2), and a compound (e-2) having one ethylenically unsaturated group: The ultraviolet-absorbing hard coat film according to claim 1, comprising (E) a quaternary ammonium salt copolymer obtained by radical copolymerization.
CH ₂ = C (R ¹ ) COZ (CH ₂ ) _k N ⁺ (R ² ) ₃ · X ⁻ (2)
(In the formula, R ¹ is H or CH ₃ , R ² is independently a hydrocarbon group having 1 to 4 carbon atoms, Z is an oxygen atom or NH group, k is an integer of 1 to 10, and X ⁻ is 1) Represents a valent anion.)   The ultraviolet ray according to claim 1 or 2, wherein a low refractive index layer having a refractive index lower than that of the ultraviolet absorbing hard coat layer is provided on the ultraviolet absorbing hard coat layer. Absorbent hard coat film. The ultraviolet-absorbing hard coat film according to any one of claims 1 to 3, wherein an adhesive layer is provided on the other surface of the transparent substrate film.