JP5181056B2 - Hard coat film or sheet, optical element, and image display device - Google Patents

Description

  The present invention relates to a hard coat film or sheet, an optical element, and an image display device. More specifically, the present invention relates to a film or sheet in which a hard coat layer excellent in flexibility, adhesion, scratch resistance, and pencil hardness is provided on a film of polyester, acrylic, polycarbonate, polyether sulfone, triacetyl cellulose or the like.

  At present, plastics are used in large quantities in various industries including the automobile industry, the home appliance industry, and the electrical and electronic industry. The reason why a large amount of plastic is used in this way is due to reasons such as lightness, low cost, and optical characteristics in addition to its processability and transparency. However, it has drawbacks such as being softer than glass and being easily scratched on the surface. In order to remedy these drawbacks, it is common practice to coat the surface with a hard coating agent.

  Thermosetting hard coat agents such as silicon paints, acrylic paints, and melamine paints are used as the hard coat agents. Of these, silicon-based hard coating agents have been frequently used because of their high hardness and excellent quality. This type of coating agent is mostly used for high value-added products such as glasses and lenses. However, it has a long curing time, is expensive, and cannot be said to be suitable for a hard coat of a film or sheet that is continuously processed (hereinafter, “film or sheet” may be referred to as films).

  In recent years, photosensitive acrylic hard coating agents have been developed and used. The photosensitive hard coat agent is cured immediately upon irradiation with light such as ultraviolet rays, so that a hard film is formed. Therefore, the processing speed is high and the scratch resistance is excellent. Due to the low cost, it is now the mainstream of hard coating agents. In particular, it is suitable for continuous processing of films such as polyester.

  Examples of the resin used as a material for the films include polyester, polyacrylate, acrylic, polycarbonate, vinyl chloride, triacetyl cellulose, and polyether sulfone. Resins selected from polyester, polycarbonate, and acrylic are one of the most widely used resins due to various excellent characteristics.

  Such resin films are used as glass scattering prevention films, automobile light shielding films, whiteboard surface films, and system kitchen surface antifouling films. In terms of electronic materials, they are widely used as functional films or sheets for touch panels, liquid crystal displays, CRT flat televisions and the like. All of these are coated with a hard coating agent in order to prevent the surface from being scratched (Patent Documents 1 and 2).

  Furthermore, in CRT and LCD displays using films coated with hard coat agents, the display screen is difficult to see due to reflection, and the eyes are likely to become tired. Hard coat processing with a certain amount is necessary. As a method for preventing surface reflection, a method in which an inorganic filler or an organic fine particle filler is dispersed in a photosensitive resin is coated on a film, and the surface is made uneven to prevent reflection (AG treatment). A method in which a multilayer structure is formed on a film in the order of a high refractive index layer and a low refractive index layer, and the reflection is caused by the difference in refractive index to prevent reflection (AR processing), or AG / AR processing in which the above two methods are combined There are methods.

  In Patent Documents 3 and 4, divinyl aromatic compound (a) and monovinyl aromatic compound (b) are polymerized in an organic solvent at a temperature of 20 to 100 ° C. in the presence of a Lewis acid catalyst and an initiator having a specific structure. The soluble polyfunctional vinyl aromatic copolymer obtained by making it to have been disclosed is disclosed. And this soluble polyfunctional vinyl aromatic copolymer is excellent in solvent solubility and processability, and it is disclosed that the cured | curing material excellent in heat resistance and heat-resistant decomposition property can be obtained by using this. However, there is nothing that teaches its use for hard coating agents. Patent Document 5 discloses the use of this soluble polyfunctional vinyl aromatic copolymer as a hologram material.

JP 2003-306619 A JP 2006-240292 A JP 2004-123873 A Japanese Patent Laid-Open No. 2005-213443 WO2006 / 95610

  In hard coat layers used for base films such as polycarbonate films used for films with hard coat layers, polyfunctional resins with high crosslink density are often used to improve their hardness. Therefore, not only the shrinkage of curing is large and the adhesiveness is insufficient, but also the flexibility is insufficient, which causes problems such as cracks during processing and actual use. Conversely, if a resin with a low number of functional groups is used with an emphasis on adhesion, there is a problem that the hardness and scratch resistance are not sufficiently improved. As a result, for base films such as polycarbonate that require a high degree of flexibility There are no satisfactory hard coat agents, and hard coat films having good bendability, adhesion and scratch resistance when high-flexibility polycarbonate is used as the base film, There is a need for stacked optical elements and image display devices.

  The present invention has a particularly good adhesion to a film or sheet such as a highly flexible polycarbonate or the like, an excellent scratch resistance, and a hard coat film or sheet that can withstand bending, and further, they are laminated. An object is to provide an optical element and an image display device.

  As a result of intensive studies to solve the above problems, the present inventors have found that a hard coat layer forming material having a specific composition is excellent, and have completed the present invention.

（式中、Ｒ¹は炭素数６〜３０の芳香族炭化水素基を示す。）で表される未反応のビニル基を含有する構造単位の含有量が全ての単量体由来の構造単位の総モル数に対し、１０〜９０モル％である可溶性多官能ビニル芳香族共重合体、
（Ｂ）成分：分子中に少なくとも２個以上の（メタ）アクリロイル基を有する光硬化型多官能（メタ）アクリレ−ト、及び
（Ｃ）成分：光重合開始剤、を含有し、
（Ａ）成分の配合量が１０〜７０ｗｔ％、（Ｂ）成分の配合量が８９．９〜２０ｗｔ％及び（Ｃ）成分の配合量が０．１〜１０ｗｔ％であることを特徴とするハードコートフィルム又はシートである。 That is, the present invention is a film or sheet having a hard coat layer formed by photocuring a coating film of a hard coat layer forming material on at least one surface of a transparent plastic film or sheet, and the hard coat layer forming material But,
Component (A): a copolymer obtained by copolymerizing divinyl aromatic compound (a) 20 to 99 mol% and monovinyl aromatic compound (b) 80 to 1 mol%, and the divinyl aromatic compound The following formula (a1) derived from (a)

(In the formula, R ¹ represents an aromatic hydrocarbon group having 6 to 30 carbon atoms.) The content of the structural unit containing an unreacted vinyl group represented by: A soluble polyfunctional vinyl aromatic copolymer that is 10 to 90 mol% based on the total number of moles;
(B) component: a photocurable polyfunctional (meth) acrylate having at least two (meth) acryloyl groups in the molecule, and (C) component: a photopolymerization initiator,
The amount of component (A) is 10 to 70 wt%, the amount of component (B) is 89.9 to 20 wt%, and the amount of component (C) is 0.1 to 10 wt%. It is a coat film or sheet.

Here, when the hard coat layer forming material satisfies one or more of the following, an excellent hard coat film or sheet is provided.
1) The component (B) is a photocurable polyfunctional (meth) acrylate containing a polyfunctional urethane (meth) acrylate having two or more (meth) acryloyl groups in one molecule.
2) A soluble polyfunctional component (A) having a number average molecular weight Mn of 500 to 100,000 and a molecular weight distribution (Mw / Mn) represented by a ratio of the weight average molecular weight Mw to the number average molecular weight Mn of 50.0 or less. It must be a vinyl aromatic copolymer.
3) The component (A) is a soluble polyfunctional vinyl aromatic copolymer having a phenolic hydroxyl group at a part of its terminals.
4) The amount of phenolic hydroxyl group introduced at the terminal is 2.2 or more per molecule.
5) The hard coat layer forming material is used in the state of being mixed with the component (E): diluent, and the amount of the component (E) is 100 parts by weight of the hard coat layer forming material. 5.0 to 500 parts by weight.

  The present invention also provides an optical element in which the above hard coat film or sheet is laminated and an image display device having the optical element. Furthermore, the present invention is an image display device in which the above hard coat film or sheet is disposed on the outer surface of the image display surface of the panel.

  The hard coat layer forming material used for the hard coat film or sheet of the present invention is synergistically enhanced at the interface between the component (A) and the component (B), and has improved adhesion to base films. It is possible to improve. Therefore, it can be advantageously used for base films such as untreated polyester (not subjected to easy adhesion treatment), acrylic, polycarbonate, polyethersulfone, triacetylcellulose and the like. Films on which a hard coat layer obtained by curing is formed have excellent flexibility, scratch resistance, and pencil hardness. Moreover, since the adhesiveness with respect to untreated base film is excellent, the film with a hard-coat layer can be manufactured cheaply. The films on which the hard coat layer of the present invention is formed can be suitably used for applications in the fields of optics and electronics. Films on which such a hard coat layer is formed are particularly suitable for the device field that requires high hardness and low reflection, such as plastic optical parts, touch panels, flat displays, and film liquid crystal elements.

The present invention will be described in detail below.
The hard coat film or sheet of the present invention (hereinafter also referred to as hard coat film) is provided with a coating film of a hard coat layer forming material on at least one side of a transparent plastic film or sheet (hereinafter also referred to as base film). A hard coat layer obtained by photocuring this is formed.

  First, a hard coat layer forming material (hereinafter also referred to as a hard coat material) and each component blended therein will be described in detail.

  The hard coat layer forming material includes (A) component, (B) component and (C) component as essential blending components, the blending amount of (A) component is 10 to 70 wt%, and the blending amount of (B) component 89.9-20 (wt%) and the blending amount of the component (C) is 0.1-10 wt%. The hard coat layer forming material functions as a photosensitive resin composition.

  The component (A) is a copolymer obtained by copolymerizing divinyl aromatic compound (a) 20 to 99 mol% and monovinyl aromatic compound (b) 80 to 1 mol%, and divinyl aromatic The content of a structural unit containing an unreacted vinyl group represented by the above formula (a1) derived from the compound (a) (hereinafter referred to as structural unit (a1)) is a structural unit derived from all monomers. It is a soluble polyfunctional vinyl aromatic copolymer (hereinafter also referred to as copolymer (A)) in an amount of 10 to 90 mol% based on the total number of moles.

  The copolymer (A) is a copolymer obtained by copolymerizing the divinyl aromatic compound (a) and the monovinyl aromatic compound (b), and the content of the structural unit (a1) is 10 to 10. It is a soluble polyfunctional vinyl aromatic copolymer that is 90 mol%. And it has the structural unit (a) derived from the divinyl aromatic compound (a) and the structural unit (b) derived from the monovinyl aromatic compound (b). The structural unit (a1) is one type of the structural unit (a) and occupies a part of the structural unit (a). Here, soluble means that it is soluble in toluene, xylene, tetrahydrofuran, dichloroethane or chloroform.

  Since the copolymer (A) is a soluble polyfunctional vinyl aromatic copolymer obtained by copolymerizing a monomer containing a divinyl aromatic compound, the branched structural unit derived from the divinyl aromatic compound or other Although it has a structural unit, the abundance of the crosslinked structural unit is limited to the extent that it is soluble. Therefore, it is a polyfunctional vinyl aromatic copolymer having a certain amount or more of the structural unit (a1). The unreacted vinyl group in the structural unit (a1) is also referred to as a pendant vinyl group, which exhibits polymerizability and can be polymerized by further polymerization treatment to give a solvent-insoluble thermosetting resin. Moreover, the number of terminals can be increased by increasing the number of branched structural units. The soluble polyfunctional vinyl aromatic copolymer as described above is disclosed in Patent Documents 3 and 4 above.

  The copolymer (A) preferably has a phenolic hydroxyl group derived from the polymerization additive at the terminal. By introducing a phenolic hydroxyl group at the end of the copolymer (A), a hard coat layer with improved adhesion can be obtained.

  When the copolymer (A) has a phenolic hydroxyl group at a part of the terminal of the polymer, the amount of the phenolic hydroxyl group at the terminal is preferably 2.2 (number / molecule) or more. Preferably it is 2.5 (pieces / molecule) or more, more preferably 3.0 (pieces / molecule) or more. Adhesiveness can be further improved by introducing 2.2 (number / molecule) or more of a phenolic hydroxyl group into the terminal of the copolymer (A). The upper limit of the amount of the terminal phenolic hydroxyl group is not limited, but is preferably 10 (number / molecule) or less, more preferably 7 (number / molecule) or less.

  The copolymer (A) is obtained by copolymerizing 20 to 99 mol% of the divinyl aromatic compound (a) and 1 to 80 mol% of the monovinyl aromatic compound (b). It has a structural unit derived from the divinyl aromatic compound (a) and a structural unit derived from the monovinyl aromatic compound (b) corresponding to the composition ratio of the monomer. The copolymer (A) preferably contains 25 to 95 mol% of the structural unit (a) derived from the divinyl aromatic compound relative to the structural units derived from all the monomers. More preferably, it is 30-90 mol%. When the structural unit (a) is less than 20 mol%, the heat resistance of the cured product is insufficient, which is not preferable. On the other hand, when the structural unit (a) derived from the divinyl aromatic compound (a) exceeds 99 mol%, the moldability is lowered, which is not preferable.

  The divinyl aromatic compound (a) generates a structural unit (a1) having a pendant vinyl group in addition to branching or crosslinking the copolymer (A), and is heat resistant when the copolymer (A) is thermally cured. It plays an important role as a cross-linking component for the expression of.

  Examples of the divinyl aromatic compound (a) include divinylbenzene (both isomers of m- and p-), divinylnaphthalene (including each isomer), divinylbiphenyl (including each isomer), and the like. However, it is not limited to these. Moreover, these can be used individually or in combination of 2 or more types. In particular, from the viewpoint of cost and availability, divinylbenzene (both isomers of m- and p-), and when higher heat resistance is required, divinylnaphthalene (including each isomer), divinylbiphenyl ( Each isomer is preferred).

Since the structural unit (a1) represented by the formula (a1) is derived from the divinyl aromatic compound (a), it is possible to understand R ¹ in the formula (a1) from the divinyl aromatic compound (a). it can. That is, when divinylbenzene is used as the divinyl aromatic compound, R ¹ is a phenylene group, and other divinyl aromatic compounds such as divinylbiphenyl are also understood to be residues generated by removing two vinyl groups therefrom. .

  Monovinyl aromatic compound (b) is used with divinyl aromatic compound (a) to improve the solvent solubility and processability of copolymer (A).

  Examples of monovinyl aromatic compounds (b) include, but are not limited to, styrene, nuclear alkyl substituted monovinyl aromatic compounds, α-alkyl substituted monovinyl aromatic compounds, β-alkyl substituted styrenes, alkoxy substituted styrenes, and the like. It is not a thing. In order to prevent polymer gelation and improve solubility in solvents and processability, especially styrene, ethylvinylbenzene (both isomers of m- and p-), ethylvinylbiphenyl (including each isomer) Is preferred from the viewpoint of cost and availability.

  In addition to the structural units derived from the monovinyl aromatic compound (a) and the divinyl aromatic compound (b), the copolymer (A) is not limited to the effects of the present invention. Structural units derived from other monomer components (c) such as aliphatic compounds, divinyl aliphatic compounds and monovinyl aliphatic compounds can be introduced.

  Specific examples of the other monomer component (c) include 1,3,5-trivinylbenzene, 1,3,5-trivinylnaphthalene, 1,2,4-trivinylcyclohexane, ethylene glycol diester. Examples thereof include, but are not limited to, acrylate and butadiene. These can be used alone or in combination of two or more. The structural unit (c) derived from the other monomer component (c) is the total amount of the structural unit (a) derived from the monomer component (a) and the structural unit (b) derived from the monomer component (b). It is used within a range of less than 30 mol%.

  The number average molecular weight Mn (wherein Mn is the number average molecular weight in terms of standard polystyrene measured using gel permeation chromatography) of the copolymer (A) is preferably 500 to 100,000, more preferably 700 to 50,000. More preferably, it is 1000-20000. If the Mn is less than 500, the viscosity of the soluble polyfunctional vinyl aromatic polymer is too low, so that it becomes difficult to form a thick film, and the workability is lowered. Since it becomes easy to produce | generate and a viscosity becomes high, when shape | molding into films, the fall of an external appearance is caused and it is unpreferable. The molecular weight distribution (Mw / Mn) obtained from Mn and the weight average molecular weight Mw is 50.0 or less, preferably 30.0 or less. Especially preferably, it is 2-10. When Mw / Mn exceeds 50.0, problems such as deterioration of processing characteristics of the soluble polyfunctional vinyl aromatic copolymer and generation of gel occur.

  The copolymer (A) can be obtained by cationic copolymerization of the above monomer in the presence of one or more promoters selected from (I) Lewis acid catalyst and (II) ester compound. In the case of obtaining a soluble polyfunctional vinyl aromatic copolymer (A) having a phenolic hydroxyl group at the terminal, (I) Lewis acid catalyst and (II) ester compound, and (III) one or more selected from phenolic compounds Use polymerization additives.

  Next, the manufacturing method of a copolymer (A) is demonstrated. In the production method of the copolymer (A), the divinyl aromatic compound (a) is 20 to 99 mol%, preferably 25 to 95 mol%, more preferably 30 to 90 mol%, and the monovinyl aromatic compound is 80 A monomer component containing ˜1 mol%, preferably 75 to 5 mol%, more preferably 70 to 10 mol% is copolymerized. At this time, the other monomer component (c) can be used in an amount of less than 30 mol% as described above.

  The (I) Lewis acid catalyst used in the production of the copolymer (A) is a compound composed of a metal ion (acid) and a ligand (base), and can receive an electron pair. Can be used without any particular restrictions.

  (II) As a promoter, 1 or more types chosen from an ester compound are mentioned. Among them, ester compounds having 4 to 30 carbon atoms are preferably used from the viewpoint of polymerization rate and control of molecular weight distribution of the polymer. From the viewpoint of availability, ethyl acetate, propyl acetate and butyl acetate are preferably used.

(III) The role of the polymerization additive is to introduce a phenolic hydroxyl group that causes a chain transfer reaction with the polymerization active species during the polymerization reaction and enables functionalization such as adhesiveness at the terminal of the copolymer (A). It is a compound that fulfills

  Such a polymerization additive is not particularly limited as long as it is a phenolic compound, but has a phenolic hydroxyl group having 6 to 30 carbon atoms such as phenol, alkylphenol, dialkylphenol, phenylphenol, alkylphenylphenol, naphthol, and alkylnaphthol. Examples thereof include one or more phenolic compounds selected from the group consisting of aromatic hydrocarbon compounds. Of these phenol compounds, phenol and 2,6-xylenol are preferably used from the viewpoint of reactivity and availability.

  The (I) Lewis acid catalyst is used in the range of 0.001 to 10 mol, more preferably 0.001 to 0.01 mol, relative to 1 mol of the (III) polymerization additive. When the amount of the Lewis acid catalyst used exceeds 10 moles with respect to 1 mole of the polymerization additive, the polymerization rate becomes too high, so that not only the control of the molecular weight distribution becomes difficult, but also the introduction amount of the phenolic hydroxyl group decreases. Therefore, it is not preferable. In addition, the range of 0.001 to 1.0 mol of (I) Lewis acid catalyst is good with respect to 1 mol in total of all monomers.

  (II) The cocatalyst is used in the range of 0.001 to 10 mol, more preferably 0.01 to 1 mol, per mol of (III) polymerization additive. In addition, the range of (II) promoter is 0.01-1.0 mol with respect to 1 mol in total of all monomers.

  The (III) polymerization additive is preferably used in the range of 0.005 to 50 mol, more preferably 0.01 to 10 mol, with respect to a total of 1 mol of all monomers.

  The polymerization temperature is in the range of 20 to 120 ° C, preferably 40 to 100 ° C. When the polymerization temperature exceeds 120 ° C., the selectivity of the reaction decreases, causing problems such as an increase in the molecular weight distribution and the generation of gel, and when the polymerization is carried out at a temperature below 20 ° C., the molecular weight of the resulting copolymer increases. However, this is not preferable because it causes a decrease in moldability.

  The method for recovering the copolymer after the termination of the polymerization reaction is not particularly limited. For example, a commonly used method such as a steam stripping method or precipitation with a poor solvent may be used.

  Next, the component (B) will be described. As the component (B), a photocurable polyfunctional (meth) acrylate having at least two (meth) acryloyl groups in the molecule is used.

  Specific examples of the component (B) include polyethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane polyethoxytri (meth) acrylate, and ditrimethylolpropane. Tetra (meth) acrylate, glycene polypropoxytri (meth) acrylate, di (meth) acrylate of ε-caprolactone adduct of hydroxybivalic acid neopenglycol (for example, KAYARAD HX-220, manufactured by Nippon Kayaku Co., Ltd.) , HX-620, etc.), pentaerythritol tetra (meth) acrylate, poly (meth) acrylate of a reaction product of dipentaerythritol and ε-caprolactone, dipentaerythritol hexa (meth) acrylate Dipentaerythritol penta (meth) acrylate, tripentaerythritol octa (meth) acrylate, tripentaerythritol hepta (meth) acrylate, and epoxy (meth) acrylate which is a reaction product of polyglycidyl compound and (meth) acrylic acid . Here, as the polyglycidyl compound, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, hexahydrophthalic acid diglycidyl ester, glycerin polyglycidyl ether, glycerin polyethoxyglycidyl ether , Trimethylolpropane polyglycidyl ether, trimethylolpropane polyethoxypolyglycidyl ether, and the like.

  Furthermore, specific examples of the component (B) include polyfunctional urethane acrylate which is a reaction product of a hydroxyl group-containing polyfunctional (meth) acrylate and a polyisocyanate compound. Here, examples of the hydroxyl group-containing polyfunctional (meth) acrylate include pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, and tripentaerythritol hepta (meth) acrylate. There are range isocyanate, isophorone diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, p-phenylene diisocyanate, and the like.

  These components (B) may be used alone or in admixture of two or more. Preference is given to (meth) acrylates having a molecular weight of 200 or more.

  The component (B) is one or more photocurable polyfunctional (meth) acrylates containing a polyfunctional urethane (meth) acrylate having two or more (meth) acryloyl groups in one molecule. More preferably.

As a commercial product of polyfunctional urethane (meth) acrylate having 2 or more (meth) acryloyl groups in one molecule of component (B), a specific product name is bifunctional urethane (meth) acrylate (Nipponization) “UX-2201” or “UX-8101” manufactured by Yakuhin Co., Ltd. “UF-8001”, “UF-8003”, “UX-6101”, “UX-8101” manufactured by Kyoeisha Chemical Co., Ltd., Daicel Cytec Co., Ltd. “Ebecryl 244”, “Ebecryl 284”, “Ebecryl 2002”, “Ebecryl 4835”, “Ebecryl 4883”, “Ebecryl 8807”, “Ebecryl 8700” and “Ebecryl 6700” acrylate (3) "Ebecryl 254", "Ebecr" l 264 "," Ebecryl 265 "), tetrafunctional urethane (meth) acrylate (" Ebecryl 8210 "manufactured by Daicel-Cytec Co., Ltd.), hexafunctional urethane (meth) acrylate (" Ebecryl 1290k "manufactured by Daicel-Cytec Co., Ltd.) , “Ebecryl 5129”, “Ebecryl 220”).

  Next, the photopolymerization initiator of component (C) will be described. Examples of the photopolymerization initiator include benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, and benzoin isobutyl ether; acetophenone, 2,2-diethoxy-2-phenylacetophenone, 2,2-diethoxy-2 -Phenylacetophenone, 1,1-dichloroacetophenone, 2-hydroxy-2-methyl-phenylpropan-1-one, diethoxyacetophenone, 1-hydroxyhexylphenyl ketone, 2-methyl-1- [4- (methylthio) Acetophenones such as phenyl] -2-morpholinopropan-1-one; ant such as 2-ethylanthraquinone, 2-tertiarybutylanthraquinone, 2-chloroanthraquinone, 2-amylanthraquinone Quinones; thioxanthones such as 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone; ketals such as acetophenone dimethyl ketal and benzyldimethyl ketal; benzophenone, 4-benzoyl-4′-methyldiphenyl sulfide Benzophenones such as 4,4′-bismethylaminobenzophenone; phosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide It is done.

  These can be used alone or as a mixture of two or more thereof, and further, tertiary amines such as triethanolamine and methyldiethanolamine, N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester Can be used in combination with an accelerator such as a benzoic acid derivative.

  Commercially available photopolymerization initiators include, for example, Irgacure 184, 369, 651, 500, 819, 907, 784, 2959, CGI-1700, -1750, -1850, CG24-61, Darocur l116, 1173 (above, Ciba Specialty Chemicals Co., Ltd.), Lucirin TPO, LR8883, LR8970 (above, manufactured by BASF), Ubekrill P36 (manufactured by UCB), and the like.

In the hard coat layer forming material, the component (A), the component (B) and the component (C) are each composed of the component (A): 10 to 70 wt%, the component (B): 89.9 to 20 (wt%), ( C) Component: It is necessary to contain 0.1 to 10 wt%. More preferably, they are (A) component: 15-40 wt%, (B) component: 55-84.9, (C) component: 0.1-5 wt%. When the blending ratio of the component (A) and the component (B) is within the above range, the flexibility and scratch resistance of the hard coat layer are synergistically improved. Further, when the component (C) is less than 0.1 wt%, it is not preferable because insufficient curing tends to occur and adhesion and scratch resistance are reduced. Further, if the component (C) is used in excess of 10 wt%, it is not preferable because flexibility is lowered or productivity is lowered.

  The hard coat layer forming material can be used by mixing with the diluent of component (E). Here, the component (E) is not calculated as a component of the hard coat layer forming material.

  Specific examples of the diluent include lactones such as γ-butyrolactone, γ-valerolactone, γ-caprolactone, γ-heptalactone, α-acetyl-γ-butyrolactone, and ε-caprolactone; dioxane, 1,2- Ethers such as dimethoxymethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether Carbonates such as ethylene carbonate and propylene carbonate; methyl ethyl keto , Ketones such as methyl isobutyl ketone, cyclohexanone, acetophenone; phenols such as phenol, cresol, xylenol; ethyl acetate, butyl acetate, ethyl cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate Esters such as toluene; hydrocarbons such as toluene, xylene, diethylbenzene, cyclohexane; halogenated hydrocarbons such as trichloroethane, tetrachloroethane, and monochlorobenzene; and organic solvents such as petroleum solvents such as petroleum ether and petroleum naphtha It is done. These diluents may be used alone or in combination of two or more.

  (E) The usage-amount of a component shall be 5.0-500 weight part with respect to 100 weight part of hard-coat layer forming materials which have (A) component, (B) component, and (C) component as an essential component. Is preferred. More preferably, it is 10.0-300 weight part. Most preferably, it is 20.0-100 weight part. The component (E) is calculated as the external number of the hard coat layer forming material.

  In addition, leveling agents, antifoaming agents, UV absorbers, light stabilizers, various inorganic and organic fillers, antifungal agents, antibacterial agents, etc., are added to the hard coat layer forming material as necessary. Functionality can also be imparted.

  The hard coat layer forming material used to obtain the hard coat films of the present invention includes the above component (A), component (B), component (C), and component (D), component (E) and It can be obtained by mixing other components in any order. This hard coat layer forming material is stable over time.

Next, a method for obtaining a film or sheet having the hard coat layer of the present invention from the hard coat layer forming material will be described.
First, the hard coat layer forming material is applied to one or both sides of a transparent plastic film or sheet (base film) on which a hard coat layer is to be provided, dried, and then irradiated with light to form a cured film. Can be obtained. The coating amount of the hard coat layer forming material is ² to 50 g / m ² , preferably 5 to 30 g / m ² after drying, or ^{2 to} 50 μm, preferably 5 to 30 μm after drying.

  As resin which comprises the base film which should provide a hard-coat layer, polyester, a polypropylene, polyethylene, a polyacrylate, a polycarbonate, a triacetyl cellulose, a polyether sulfone, a cycloolefin type polymer etc. are mentioned, for example. Although it does not specify about the thickness of base film, the thing of 50 micrometers-550 mm is preferable.

  Examples of methods for applying the hard coat layer forming material on the surface of the base film include bar coater coating, Mayer bar coating, air knife coating, gravure coating, reverse gravure coating, offset printing, flexographic printing. And screen printing. The base film to be used may be one having a handle or one having an easy-adhesion layer, but is preferably one having no easy-adhesion layer in view of cost.

  Examples of the light for curing the hard coat layer forming material include ultraviolet rays and electron beams. In addition, as the light source, an ultraviolet irradiation device having a xenon lamp, a high-pressure mercury lamp, a metal halide lamp, or the like is used in the case of curing with ultraviolet rays, and the amount of light, the arrangement of the light sources, and the like are adjusted as necessary. When using a high-pressure mercury lamp, it is preferable to cure at a conveyance speed of 5 to 60 m / min for one lamp having a light quantity of 80 to 120 W / cm.

  The optical element of the present invention is a laminate of the hard coat film or sheet of the present invention, which is useful for an image display device or the like. Moreover, the image display apparatus of this invention arrange | positions the hard coat film or sheet | seat of this invention on the image display surface of a panel, and raises the hardness of the display surface of a panel. The hard coat film or sheet of the present invention can be used for various applications requiring hardness.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not restrict | limited by these. In addition, the measurement of the molecular weight, molecular weight distribution, etc. in a synthesis example performed sample preparation and a measurement by the method shown below.

1) Using molecular weight and molecular weight distribution GPC of copolymer (A) (manufactured by Tosoh Corporation, HLC-8120GPC), using tetrahydrofuran as a solvent, flow rate of 1.0 ml / min, column temperature of 38 ° C., and a calibration curve using monodisperse polystyrene. I went.

2) Polymer structure The polymer structure was determined by ¹³ C-NMR and ¹ H-NMR analysis using a JNM-LA600 type nuclear magnetic resonance spectrometer manufactured by JEOL. Using chloroform -d ₁ as a solvent, was used resonance line of tetramethylsilane as an internal standard.

3) Terminal phenolic hydroxyl group The terminal phenolic hydroxyl group was calculated from the number average molecular weight obtained from the above GPC measurement, the terminal phenolic hydroxyl group obtained from the results of ¹ H-NMR measurement and elemental analysis.

4) Sample preparation and measurement of glass transition temperature (Tg) and softening temperature (Sp) Measurement: Uniformly apply the copolymer solution to the glass substrate so that the thickness after drying is 20 μm, and use a hot plate. Heated at 90 minutes for 30 minutes and dried. The resin film obtained together with the glass substrate is set in TMA (thermomechanical analyzer), heated to 220 ° C. at a temperature rising rate of 10 ° C./min under a nitrogen stream, and further heat-treated at 220 ° C. for 20 minutes. The remaining solvent was removed. After allowing the glass substrate to cool to room temperature, an analytical probe is brought into contact with the sample in the TMA measuring apparatus, and scan measurement is performed from 30 ° C. to 360 ° C. at a temperature rising rate of 10 ° C./min under a nitrogen stream. Tg and Sp values were determined.

5) Evaluation of heat resistance and measurement of heat discoloration The copolymer is set in a TGA (thermobalance) measuring device and scanned by scanning from 30 ° C to 320 ° C at a temperature rising rate of 10 ° C / min under a nitrogen stream. By determining the weight loss at 300 ° C. as heat resistance and visually confirming the amount of discoloration of the sample after measurement, and classifying it as A: no thermal discoloration, B: light yellow, C: brown, D: black The heat discoloration was evaluated.

Synthesis example 1
4230 g (32.4 mol) of divinylbenzene, 169 g (1.35 mol) of ethyl vinylbenzene, 1170 g (11.3 mol) of styrene, 158 g (1.8 mol) of ethyl acetate, 1649 g (13.5 g) of 2,6-xylenol Mol) and 12745 g of toluene were charged into a 30 L reactor, and 18 g (120 mmol) of diethyl ether complex of boron trifluoride was added at 70 ° C. and reacted for 2 hours. After stopping the polymerization solution with 53.3 g of 1-butanol, the reaction mixture was poured into a large amount of n-hexane at room temperature to precipitate a copolymer. The obtained copolymer was washed with n-hexane, filtered, dried and weighed to obtain 3948 g of copolymer A (yield: 70.9 wt%).

Mn of the obtained copolymer A was 2820, Mw was 10800, and Mw / Mn was 3.84. By performing ¹³ C-NMR and ¹ H-NMR analyses, resonance lines derived from the 2,6-xylenol end of copolymer A were observed. As a result of conducting an elemental analysis result of the copolymer A, it was C: 88.2 wt%, H: 7.9 wt%, and O: 3.3 wt%. The amount of phenolic hydroxyl groups introduced into the soluble polyfunctional vinyl aromatic polymer calculated from the elemental analysis results and the number average molecular weight in terms of standard polystyrene was 5.8 (pieces / molecule). Further, it contained 79.2 mol% of structural units derived from divinylbenzene and 20.7 mol% in total of structural units derived from styrene and ethylbenzene. The content of the structural unit (a1) contained in the copolymer A was 32 mol%. As a result of the TMA measurement, Tg was 275 ° C., and the softening temperature was 300 ° C. or higher. As a result of TGA measurement, the weight loss at 300 ° C. was 1.5 wt%, and the heat discoloration was A. Copolymer A was soluble in toluene, xylene, THF, dichloroethane, dichloromethane, and chloroform, and no gel was formed.

Synthesis example 2
4230 g (32.4 mol) of divinylbenzene, 169 g (1.35 mol) of ethyl vinylbenzene, 1170 g (11.3 mol) of styrene, 209 g (1.8 mol) of butyl acetate, 2771 g (16.5 mol) of phenol, toluene 11956 g was put into a 30 L reactor, 8 g of diethyl ether complex of boron trifluoride was added at 70 ° C., and reacted for 2.5 hours. After the polymerization solution was stopped with 26.7 g of 1-butanol, the reaction mixture was poured into a large amount of n-hexane at room temperature to precipitate a polymer. The obtained polymer was washed with n-hexane, filtered, dried and weighed to obtain 2606 g of copolymer B (yield: 46.8 wt%).

Mn of the obtained copolymer B was 1940, Mw was 5640, and Mw / Mn was 2.91. By performing ¹³ C-NMR and ¹ H-NMR analysis, the copolymer B was observed to have a resonance line derived from the phenol end. As a result of conducting an elemental analysis result of the copolymer B, it was C: 85.8 wt%, H: 7.2 wt%, and O: 4.7 wt%. The amount of phenolic hydroxyl group introduced into the soluble polyfunctional vinyl aromatic polymer calculated from the elemental analysis result and the number average molecular weight in terms of standard polystyrene was 4.0 (pieces / molecule). Further, 71.8 mol% of the structural units derived from divinylbenzene and 28.2 mol% of the structural units derived from styrene and ethylbenzene were contained. The content of the structural unit (a1) contained in the copolymer B was 36 mol%. As a result of TMA measurement, Tg was 272 ° C. and softening temperature was 300 ° C. or higher. As a result of TGA measurement, the weight loss at 300 ° C. was 1.5 wt%, and the heat discoloration was A. The result of measuring the total light transmittance with a turbidimeter was 88%. Copolymer B was soluble in toluene, xylene, THF, dichloroethane, dichloromethane, and chloroform, and no gel was formed.

Synthesis example 3
Divinylbenzene 28.5 mol (4059 ml), ethyl vinylbenzene 1.5 mol (213.7 ml), styrene 10.0 mol (1145.8 ml), benzyl alcohol 16 mol (1655.7 ml), ethyl acetate 4.80 mol (468.9 ml), 7111 ml of toluene (dielectric constant: 2.3) and 6222 ml of cyclohexane (dielectric constant: 2.02) were put into a 30 L reactor, and 6.4 mol of boron trifluoride was added at 30 ° C. Diethyl ether complex was added and allowed to react for 5 hours. The polymerization reaction was stopped with 2845 g of calcium hydroxide, followed by filtration and washing with 5 L of distilled water three times. After 8.0 g of butylhydroxytoluene was dissolved in the polymerization solution, the solution was concentrated using an evaporator at 40 ° C. for 1 hour. The reaction mixture was poured into a large amount of methanol at room temperature to precipitate a polymer. The obtained polymer was washed with methanol, filtered, dried and weighed to obtain 3356 g of copolymer C (yield: 67.8 wt%).

Mw of the obtained copolymer C was 6230, Mn was 2100, and Mw / Mn was 2.97. By performing ¹³ C-NMR and ¹ H-NMR analyses, in the copolymer C, resonance lines derived from the ether end, the indane end and the alcohol end were observed. The proportion of ether terminals in all oxygen-containing terminals calculated from the NMR measurement results was 79.4 mol%. From the NMR measurement results, the oxygen content derived from the ether terminal and alcohol terminal was calculated to be 2.3 wt%. As a result of conducting elemental analysis of the copolymer C, C: 90.5 wt%, H: 7.6 wt%, and O: 2.4 wt%, which were in good agreement with the NMR measurement results. The amount of the chain hydrocarbon group or aromatic hydrocarbon group introduced into the soluble polyfunctional vinyl aromatic polymer calculated from the elemental analysis result and the number average molecular weight in terms of standard polystyrene through the ether bond is 3.4 (pieces / Molecule). Moreover, 73.6 mol% in total of structural units derived from divinylbenzene, and 26.4 mol% in total of structural units derived from styrene, a structure derived from benzyl alcohol, and a structural unit derived from ethylvinylbenzene. The content of the structural unit (a1) contained in the copolymer BC was 45.3 mol%. Further, the indane structure contained in the copolymer C was present at 5.5 mol% with respect to the total of the structural units of all the monomers. As a result of TMA measurement, Tg was 289 ° C. and softening temperature was 300 ° C. or higher. As a result of TGA measurement, the weight loss at 300 ° C. was 0.3 wt%, and the heat discoloration resistance was A.
Copolymer C was soluble in toluene, xylene, THF, dichloroethane, dichloromethane, and chloroform, and no gel was formed. The cast film of copolymer C was a transparent film without cloudiness.

Examples 1-5, 7-8 and Comparative Example 1
The components shown in Table 1 and Table 2 were blended (numbers are parts by weight) to obtain a photosensitive resin composition as a hard coat material. Next, this photosensitive resin composition is applied to an untreated polycarbonate sheet (manufactured by Mitsubishi Engineering Plastics: Iupilon sheet NF-2000, sheet thickness 1.00 mm) using a spin coater, and the coated surface is subjected to a peeling treatment. A sheet having a hard coat layer (thickness of 10 to 15 μm) is irradiated with ultraviolet rays at a distance of 10 cm of a 120 W / cm high-pressure mercury lamp in an air atmosphere after pasting the performed PET protective film (thickness: 38 μm). Got.

Example 6 and Reference Example 1
The component shown in Table 1 was mix | blended and the photosensitive resin composition was obtained. Next, this photosensitive resin composition was applied to an untreated polymethyl methacrylate sheet (manufactured by Asahi Kasei: Delaglass A, sheet thickness 1.00 mm) using a spin coater. Thereafter, the same operations as in Examples 1 to 5, 7 to 11 and Comparative Example 1 were performed to obtain a sheet having a hard coat layer (thickness of 10 to 15 μm).

  About the film with a hard-coat layer obtained by each Example and each comparative example, those performance evaluation was performed with the following test method.

  Pencil hardness: According to JIS K 5400, the pencil hardness of the coated film having the above composition was measured using a pencil scratch tester. That is, on a PET film having a hard coat layer (thickness: 15 μm), a pencil was applied at a 45 degree angle and a 1 kg load was applied from above to scratch about 5 mm to confirm the degree of damage. The measurement was performed 5 times, and the pencil hardness below one rank at which scratches were observed twice or more out of 5 times was described as the result of the pencil hardness test.

Scratch resistance test: A load of 200 g / cm ² was applied to steel wool # 0000 for 200 reciprocations, the state of the scratch was confirmed using a stereomicroscope, and judged by comparison with a limit sample of five stages. Evaluation 5 means no flaws, evaluation 1 means the occurrence of flaws, and evaluations 4 and 2 mean that the degree of flaws is intermediate.

  Adhesiveness: According to JIS K 5400, 100 grids were made on the surface of the film by making 11 vertical and horizontal cuts at 1 mm intervals. After the cellophane tape was brought into close contact with the surface, the number of cells remaining without peeling when peeled at once was displayed.

  Bendability: The coated sheet was formed by bending the UV coated surface outward by 180 degrees. A: It can be bent without any abnormal appearance. B: Cracks or peeling occurs on the coating surface. C: Cracking occurs with the base material.

  Appearance: Surface cracks, whitening, cloudiness, and the like were visually determined. Evaluation A: Good B: Generation of minute cracks C: Generation of significant cracks

Explanation of symbols in the table.
SR-833S; manufactured by Sartomer, SR-833S (tricyclodecane dimethanol diacrylate)
SR-344; manufactured by Sartomer, SR-344 (polyethylene glycol (400) diacrylate)
SR-268; manufactured by Sartomer, SR-268 (tetraethylene glycol diacrylate)
EBECRYL 8405; manufactured by Daicel Cytec Co., Ltd., EBECRYL 8405 (urethane acrylate / 1,6-hexanediol diacrylate = 80/20)
EBECRYL 8402; manufactured by Daicel Cytec Co., Ltd., EBECRYL 8402 (urethane acrylate)
DPHA; manufactured by Daicel-Cytec Corporation, DPHA (dipentaerythritol hexaacrylate)
TMPTA; manufactured by Daicel Cytec Co., Ltd., TMPTA (trimethylolpropane triacrylate)
Irgacure 819; Irgacure 819 (bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide) manufactured by Ciba Specialty Chemicals
Irgacure 184; Ciba Specialty Chemicals, Irgacure 184 (1-hydroxy-cyclohexyl-phenyl-ketone)
BY16-152C: manufactured by Toray Dow Corning Silicone Co., Ltd., BY16-152C (both end methacrylate-modified silicone, methacrylic equivalent: 5100 g / mol)

Claims (10)

A film or sheet having a hard coat layer formed by photocuring a coating film of a hard coat layer forming material on at least one surface of a transparent plastic film or sheet, wherein the hard coat layer forming material is
Component (A): a copolymer obtained by copolymerizing divinyl aromatic compound (a) 20 to 99 mol% and monovinyl aromatic compound (b) 80 to 1 mol%, with a part of its ends The following formula (a1) having a phenolic hydroxyl group and derived from the divinyl aromatic compound (a)

(In the formula, R ¹ represents an aromatic hydrocarbon group having 6 to 30 carbon atoms.) The content of the structural unit containing an unreacted vinyl group represented by: A soluble polyfunctional vinyl aromatic copolymer that is 10 to 90 mol% based on the total number of moles;
(B) component: a photocurable polyfunctional (meth) acrylate having at least two (meth) acryloyl groups in the molecule, and (C) component: a photopolymerization initiator,
The amount of component (A) is 10 to 70 wt%, the amount of component (B) is 89.9 to 20 wt%, and the amount of component (C) is 0.1 to 10 wt%. Coat film or sheet.   The component (B) is a photocurable polyfunctional (meth) acrylate containing a polyfunctional urethane (meth) acrylate having two or more (meth) acryloyl groups in one molecule. The hard coat film or sheet described in 1.   Component (A) is a soluble polyfunctional vinyl having a number average molecular weight Mn of 500 to 100,000 and a molecular weight distribution (Mw / Mn) represented by the ratio of the weight average molecular weight Mw to the number average molecular weight Mn of 50.0 or less. It is an aromatic copolymer, The hard coat film or sheet | seat of Claim 1 or 2 characterized by the above-mentioned.   The transparent plastic film or sheet on which the hard coat layer is formed is a film or sheet of polyester, polypropylene, polyethylene, polyacrylate, polycarbonate, triacetylcellulose, polyethersulfone, or cycloolefin polymer. The hard coat film or sheet according to any one of 1 to 3.   The hard coat film or sheet according to claim 4, wherein the transparent plastic film or sheet on which the hard coat layer is formed is a film or sheet of polycarbonate or polymethyl methacrylate.   The hard coat film or sheet according to any one of claims 1 to 5, wherein the amount of phenolic hydroxyl group introduced into the terminal is 2.2 / molecule or more. Hard coat layer forming material
Component (E) is used in a state of being mixed with a diluent, and the amount of component (E) is 5.0 to 500 parts by weight with respect to 100 parts by weight of the hard coat layer forming material. The hard coat film or sheet according to claim 1, wherein the hard coat film is a sheet.   An optical element in which the hard coat film or sheet according to claim 1 is laminated.   An image display device comprising the hard coat film or sheet according to claim 1 disposed on an image display surface of a panel.   An image display device comprising the optical element according to claim 8.