JPWO2015098449A1 - Hard coat layer forming composition - Google Patents

Abstract

The present invention provides a composition for forming a hard coat layer in which a coating film obtained by curing is excellent in anti-blocking properties. The composition for forming a hard coat layer of the present invention has a (meth) acryloyloxy group in one molecule. And a polyfunctional (meth) acrylic compound (A) having two or more, barium titanate and / or zirconium oxide having an average primary particle diameter of 100 nm or less as a filler (B), a photopolymerization initiator (C ), An organic solvent (D), a surfactant (E), a weight average molecular weight of 10,000 to 100,000, and a methyl (meth) acrylate unit of 70% by mass or more per molecule (meth) It is a composition for hard-coat layer formation containing an acrylic polymer (F).

Description

  The present invention relates to a composition for forming a hard coat layer.

In recent years, various thin electronic devices such as a touch panel device, an organic EL display device, a liquid crystal display device, and electronic paper have been put into practical use.
For electronic devices such as touch panels, a laminate having a base material such as a PET film, a hard coat layer provided on the base material, and an index matching layer provided on the hard coat layer is used. A conductive pattern such as ITO is formed on the index matching layer of the body (see, for example, Patent Document 1).

JP2013-126718A

  A laminate in which a hard coat layer is formed on a substrate such as a PET film may then be wound before forming an index matching layer. In this winding process, when blocking (sticking) between the laminates occurs, various performances may be deteriorated. For this reason, from the viewpoint of avoiding deterioration of various performances, the hard coat layer of such a laminate is required to have performance (anti-blocking property) for preventing sticking.

  This invention is made | formed in view of the above point, and it aims at providing the composition for hard-coat layer formation in which the coating film (hard-coat layer) obtained by making it harden | cure is excellent in antiblock property.

  As a result of intensive studies by the present inventors to achieve the above object, in the composition (hard coat layer forming composition) used for forming the hard coat layer, the filler for the polyfunctional (meth) acrylic compound is used. As a coating obtained by blending barium titanate and / or zirconium oxide having a specific particle diameter and a specific (meth) acrylic polymer having 70% by mass or more of methyl (meth) acrylate units per molecule. It was found that the anti-blocking property of the film was improved, and the present invention was completed.

That is, this invention provides the following 1-8.
1. A polyfunctional (meth) acrylic compound (A) having two or more (meth) acryloyloxy groups in one molecule;
As the filler (B), barium titanate and / or zirconium oxide having an average primary particle size of 100 nm or less,
A photopolymerization initiator (C);
An organic solvent (D),
Surfactant (E),
A composition for forming a hard coat layer, comprising a (meth) acrylic polymer (F) having a weight average molecular weight of 10,000 to 100,000 and having 70% by mass or more of methyl (meth) acrylate units per molecule.
2. In the above 1, the polyfunctional (meth) acrylic compound (A) has an aromatic ring and / or a urethane bond and two or more (or three or more) (meth) acryloyloxy groups in one molecule. The composition for forming a hard coat layer as described.
3. The composition for forming a hard coat layer according to the above 1 or 2, wherein the surface of the filler (B) is modified with a compound represented by the following formula (I).
^{[R 1 - (R 3)} n] a -Si- (OR 2) 4-a (I)
(In Formula (I), R ¹ is each independently a (meth) acryloyloxy group, R ² is each independently a C 1-20 alkyl group optionally having a substituent, and 1 ≦ a <4, each R ³ is independently a divalent hydrocarbon group, and n is 0 or 1.)
4). The composition for forming a hard coat layer according to any one of the above 1 to 3, wherein the surfactant (E) is a fluorosurfactant.
5. Said 1-4 whose content of said (meth) acrylic polymer (F) is 1-20 mass parts (or 1-15 mass parts) with respect to 100 mass parts of said polyfunctional (meth) acrylic compounds (A). The composition for forming a hard coat layer according to any one of the above.
6). The composition for forming a hard coat layer according to any one of 1 to 5, wherein the filler (B) has a (meth) acryloyloxy group on the surface thereof.
7). The composition for forming a hard coat layer according to any one of 1 to 6, wherein the (meth) acrylic polymer (F) further has a styrene unit.
8). The composition for forming a hard coat layer according to any one of 1 to 7, wherein the polyfunctional (meth) acrylic compound (A) has 3 or more of the (meth) acryloyloxy groups in one molecule.

  The composition for forming a hard coat layer of the present invention can be a hard coat layer excellent in antiblock property.

FIG. 1 is a cross-sectional view schematically showing an example of a laminate having a hard coat layer formed using the composition for forming a hard coat layer of the present invention. FIG. 2: observed the cross section of the hard-coat layer formed using the composition for hard-coat layer formation of Example 3 of this application by the field emission scanning electron microscope (FE-SEM). It is the photograph showing a result (magnification 160,000 times).

The present invention will be described in detail below.
In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
Moreover, when a component contains 2 or more types of compounds, content of the said component points out content of the sum total of 2 or more types of compounds.

The composition for forming a hard coat layer of the present invention (the composition of the present invention)
A polyfunctional (meth) acrylic compound (A) having two or more (meth) acryloyloxy groups in one molecule;
As the filler (B), barium titanate and / or zirconium oxide having an average primary particle size of 100 nm or less,
A photopolymerization initiator (C);
An organic solvent (D),
Surfactant (E),
A composition for forming a hard coat layer, comprising a (meth) acrylic polymer (F) having a weight average molecular weight of 10,000 to 100,000 and having 70% by mass or more of a methyl (meth) acrylate unit per molecule. is there.

The composition of the present invention uses the filler (B) and the (meth) acrylic polymer (F) in combination, and the (meth) acrylic polymer (F) has 70% by mass or more of methyl (meth) acrylate units per molecule. Thus, the resulting hard coat layer is excellent in anti-blocking properties.
The hard coat layer obtained by using the composition of the present invention can impart anti-blocking properties to the hard coat layer by the filler (B) alone by arranging the filler (B) on the surface layer portion. . Further, the composition of the present invention contains the (meth) acrylic polymer (F), thereby improving the anti-blocking property and maintaining good optical properties (total light transmittance, haze) and high refractive index. it can.

A hard coat layer obtained using the composition of the present invention will be described below with reference to the accompanying drawings. The present invention is not limited to the attached drawings.
FIG. 2: observed the cross section of the hard-coat layer formed using the composition for hard-coat layer formation of Example 3 of this application by the field emission scanning electron microscope (FE-SEM). It is the photograph showing a result (magnification 160,000 times). In FIG. 2, 20 indicates a hard coat layer, 22 is a cross section of the hard coat layer 20, and 23 is the surface of the hard coat layer 20. It can be observed that the fillers (B) 24 are continuously arranged on the surface 23 (inside the frame). It is considered that the anti-blocking property is expressed by the arrangement of the filler (B) on the surface of the hard coat layer. In the present invention, as the FE-SEM, GEMINI Column with EsB & AsB Surface Imaging Microscope ULTRA 55 manufactured by Carl Zeiss was used.

<Polyfunctional (meth) acrylic compound (A)>
The polyfunctional (meth) acrylic compound (A) will be described below.
The polyfunctional (meth) acrylic compound (A) contained in the composition of the present invention is not particularly limited as long as it is a compound having two or more (meth) acryloyloxy groups in one molecule.
The “(meth) acryloyloxy group” means an acryloyloxy group (CH ₂ ═CHCOO—) and / or a methacryloyloxy group (CH ₂ ═C (CH ₃ ) COO—).
The number of (meth) acryloyloxy groups in the molecule of the polyfunctional (meth) acrylic compound (A) is preferably 3 or more from the viewpoint of excellent coating properties and curability of the composition of the present invention. 4-15 is more preferable.

<< Preferred embodiment of polyfunctional (meth) acrylic compound (A) >>
As a suitable aspect of a polyfunctional (meth) acryl compound (A), the compound which has an aromatic ring and / or a urethane bond further in 1 molecule is mentioned, for example.
The polyfunctional (meth) acrylic compound (A) can have one or more (one or more) aromatic rings and / or urethane bonds in one molecule. In this case, the polyfunctional (meth) acrylic compound (A) is mentioned as one of preferable embodiments having three or more (meth) acryloyloxy groups in one molecule.
In the present specification, a compound having an aromatic ring and a (meth) acryloyloxy group is called an aromatic ring-containing (meth) acrylate, and a compound having a urethane bond and a (meth) acryloyloxy group is a urethane (meth) acrylate. There is.

  Examples of the aromatic ring include condensed rings such as a benzene ring; a naphthalene ring, and a fluorene ring (fluorene) represented by the following formula. Among them, a fluorene ring is more preferable.

The (meth) acryloyloxy group can be bonded to an aromatic ring or a urethane bond directly or via a linking group. Here, examples of the linking group include heteroatoms; at least divalent aliphatic hydrocarbon groups; at least divalent aromatic hydrocarbon groups;
Examples of the hetero atom include an oxygen atom, a nitrogen atom, and a sulfur atom.
Examples of the at least divalent aliphatic hydrocarbon group include a divalent aliphatic hydrocarbon group such as an alkylene group, a cycloalkylene group, and an alkenylene group; And the like (hereinafter the same). Examples of the alkylene group include alkylene groups having 1 to 6 carbon atoms, and specific examples thereof include a methylene group, an ethylene group, a propane-1,3-diyl group, and a hexane-1,6-diyl group. . Specific examples of the cycloalkylene group include a cyclohexylene group. Specific examples of the alkenylene group include a vinylene group and a propenylene group.
Examples of the divalent aromatic hydrocarbon group include a divalent aromatic hydrocarbon group such as an arylene group and an aralkylene group; and a residue of the above divalent aromatic hydrocarbon group (hereinafter referred to as a trivalent aromatic hydrocarbon group). The same)). Specific examples of the arylene group include a phenylene group, a biphenyl-4,4′-diyl group, and a diphenylmethane-4,4′-diyl group. Specific examples of the aralkylene group include a benzylene group.

(Aspect having an aromatic ring)
Commercially available products can be used as the aromatic ring-containing (meth) acrylate, and specific examples thereof include fluorene-containing acrylate (trade name: Ogsol EA-HC936, manufactured by Osaka Gas Chemical Co., Ltd., weight average molecular weight: 689, 1 molecule. Among them, the number of acryloyloxy groups: 4) is preferred.
The aromatic ring-containing (meth) acrylate may not have a urethane bond.

(Aspect having a urethane bond)
When the polyfunctional (meth) acrylic compound (A) is urethane (meth) acrylate, such a compound is obtained, for example, by a reaction between an isocyanate compound and a hydroxy compound. At this time, if the number of (meth) acryloyl groups possessed by the reaction product is 2 or more or 3 or more, either of the isocyanate compound and the hydroxy compound to be used may have a (meth) acryloyloxy group. The reaction ratio is not particularly limited.

The isocyanate compound is not particularly limited as long as it is a compound having one or more isocyanate groups, and examples thereof include polyisocyanate.
The polyisocyanate is not particularly limited as long as it is a polyisocyanate having two or more isocyanate groups in one molecule. For example, an aliphatic polyisocyanate such as hexamethylene diisocyanate (HDI); transcyclohexane-1,4-diisocyanate , Cycloaliphatic polyisocyanates such as isophorone diisocyanate (IPDI), bis (isocyanate methyl) cyclohexane (hydrogenated XDI), dicyclohexylmethane diisocyanate (hydrogenated MDI); tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), phenylene diisocyanate , Polymethylene polyphenylene polyisocyanate, xylylene diisocyanate (XDI), tetramethyl xylylene diisocyanate (TMXD) ), Tolidine diisocyanate (TODI), naphthalene diisocyanate (NDI), triphenylmethane triisocyanate and other aromatic polyisocyanates; these isocyanurates may be used, and these may be used alone or in combination of two or more. May be used in combination.
Of these, aliphatic polyisocyanates and alicyclic polyisocyanates are preferable, and HDI, IPDI, hydrogenated XDI, and hydrogenated MDI are more preferable.

  When the hydroxy compound has two or more or three or more (meth) acryloyloxy groups, examples of such a hydroxy compound include pentaerythritol such as pentaerythritol di (meth) acrylate and pentaerythritol tri (meth) acrylate. Poly (meth) acrylates; polypentaerythritol poly (meth) acrylates such as dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, etc., among others Pentaerythritol triacrylate (PETA) and dipentaerythritol pentaacrylate (DPPA) are preferable.

When the molecular weight of the polyfunctional (meth) acrylic compound (A) (when the polyfunctional (meth) acrylic compound (A) is a polymer (including oligomer)) or a mixture of a plurality of polyfunctional (meth) acrylic compounds The molecular weight can be a weight average molecular weight.) Can be less than 10,000, preferably 100 to 5,000, more preferably 400 to 2,000.
In the present invention, the weight average molecular weight is measured in terms of standard polystyrene by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent.

A polyfunctional (meth) acrylic compound (A) may be used individually by 1 type, and may use 2 or more types together.
A combination of two or more polyfunctional (meth) acrylic compounds (A) is preferably a combination of an aromatic ring-containing (meth) acrylate and a urethane (meth) acrylate, such as a fluorene-containing acrylate and hexamethylene. A combination of urethane acrylate obtained by reacting diisocyanate and dipentaerythritol pentaacrylate is more preferable.
Mass ratio of aromatic ring-containing (meth) acrylate and urethane (meth) acrylate (aromatic ring-containing (meth) acrylate: urethane (meth) acrylate) is excellent in haze, total light transmittance, high refractive index, and pencil hardness. From the viewpoint, 5:95 to 80:20 is preferable, and 5:95 to 50:50 is more preferable.

<Filler (B)>
The filler (B) will be described below. The composition of the present invention contains barium titanate (BaTiO ₃ ) and / or zirconium oxide (ZrO ₂ ) having an average primary particle size of 100 nm or less as the filler (B).
In the present invention, the filler (B) can function as a high refractive index adjusting agent for increasing the refractive index of the obtained hard coat layer.
The filler (B) is preferably barium titanate from the viewpoint that it is excellent in anti-blocking properties and excellent in refractive index and haze.
The average primary particle diameter of the filler (B) is preferably 5 to 100 nm, more preferably 10 to 30 nm, from the viewpoint of excellent antiblocking properties and excellent refractive index, haze, transmittance, and coating film appearance. Is more preferable.
In the present invention, the average primary particle size is measured by observing primary particles of the filler (B) with a field emission scanning electron microscope (FE-SEM) and measuring the particle size of 100 arbitrarily selected primary particles. The value obtained by calculating the average of the measurement results.
From the viewpoint that the filler (B) is more excellent in anti-blocking properties and is excellent in controlling the dispersibility of the filler, one preferred embodiment is colloidal (wet).

  The filler (B) is excellent in anti-blocking properties, and maintains (meth) acryloyloxy on the surface from the viewpoint of excellent coating appearance while maintaining good optical properties (total light transmittance, haze) and high refractive index. It preferably has a group. In this specification, when barium titanate or zirconium oxide has a (meth) acryloyloxy group on the surface thereof, such a filler may be referred to as a filler (b).

  Examples of the filler (B) include untreated barium titanate, untreated zirconium oxide, and the filler (b). Examples of the filler (b) include barium titanate having a (meth) acryloyloxy group on its surface and zirconium oxide having a (meth) acryloyloxy group on its surface.

  In the filler (b), barium titanate or zirconium oxide and the (meth) acryloyloxy group can be bonded directly or via a linking group. The linking group has the same meaning as described above.

  The filler (b) is not particularly limited for its production. For example, by reacting the raw material barium titanate and / or zirconium oxide with a silane coupling agent, the surface of the filler can be modified with a silane coupling agent.

The silane coupling agent used when producing the filler (b) is not particularly limited. Examples of the silane coupling agent include compounds represented by the following formula (I).
^{[R 1 - (R 3)} n] a -Si- (OR 2) 4-a (I)
In formula (I), R ¹ are each independently (meth) acryloyloxy group, R ² are each independently having 1 to 20 carbon atoms which may have a substituent alkyl group, 1 ≦ a <4, each R ³ is independently a divalent hydrocarbon group, and n is 0 or 1.
Examples of the alkyl group having 1 to 20 carbon atoms that is R ² include a methyl group, an ethyl group, a propyl group, a butyl group, and an octyl group. Among them, an alkyl group having 1 to 18 carbon atoms is preferable, An alkyl group having 1 to 6 carbon atoms is more preferable.
As the substituent that the alkyl group have 1 to 20 carbon atoms is R ^2, it is not particularly limited, for example, hydroxy group, an amino group, and a carbonyl group.

Examples of the divalent hydrocarbon group as R ³ include an alkylene group having 1 to 6 carbon atoms, and specific examples thereof include a methylene group, an ethylene group, a propane-diyl group, and a hexane-diyl group. Can be mentioned.
Examples of the compound represented by the formula (I) include 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxymethyltrimethoxysilane, 3-methacryloxyethyltriethoxysilane, and the like. These may be used alone or in combination of two or more.

  The content of the filler (B) is superior in anti-blocking properties, and from the viewpoint of excellent coating appearance while maintaining good optical properties (total light transmittance, haze) and high refractive index, polyfunctional (meta) The amount is preferably 5 to 200 parts by mass and more preferably 20 to 150 parts by mass with respect to 100 parts by mass of the acrylic compound (A).

<Photopolymerization initiator (C)>
The photopolymerization initiator (C) will be described below.
The photopolymerization initiator (C) contained in the composition of the present invention is not particularly limited as long as the vinyl functional group can be polymerized by light. For example, an alkylphenone photopolymerization initiator, acetophenones, Examples include benzophenones, Michler benzoylbenzoate, α-amyloxime ester, tetramethylthiuram monosulfide, benzoins, benzoin methyl ether, thioxanthones, propiophenones, benzyls, acylphosphine oxides, etc. One species may be used alone, or two or more species may be used in combination.
Of these, alkylphenone photopolymerization initiators are preferred from the viewpoints of light stability, high efficiency of photocleavage, compatibility, low volatility, and low odor.
Specific examples of the alkylphenone photopolymerization initiator include 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, and 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one and the like.

  The content of the photopolymerization initiator (C) is preferably 1 to 15 parts by mass with respect to 100 parts by mass of the polyfunctional (meth) acrylic compound (A) from the viewpoint of excellent curability of the composition of the present invention. 3-10 mass parts is more preferable.

<Organic solvent (D)>
The organic solvent (D) will be described below. The organic solvent (D) contained in the composition of the present invention is not particularly limited, and examples thereof include alicyclic hydrocarbons such as cyclohexane, methylcyclohexane and decalin; aromatic hydrocarbons such as benzene, toluene and xylene. Halides such as methylene chloride and chloroform; Ethers such as tetrahydrofuran and dialkyl ether; Esters such as ethyl acetate, butyl acrylate and methyl methacrylate; Ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; Glycol ethers These may be used alone or in combination of two or more.

  The content of the organic solvent (D) is based on 100 parts by mass of the polyfunctional (meth) acrylic compound (A) from the viewpoint of excellent compatibility between the polyfunctional (meth) acrylic compound (A) and the filler (B). 100 to 500 parts by mass is preferable, and 200 to 400 parts by mass is more preferable.

<Surfactant (E)>
The surfactant (E) will be described below. The surfactant (E) contained in the composition of the present invention is not particularly limited, and conventionally known surfactants can be used.
As the surfactant (E), a basic surfactant and a fluorosurfactant are preferable, and a fluorosurfactant is more preferable because the antiblocking effect is more excellent. Since the fluorine-containing surfactant is hydrophobic, the fluorine-containing surfactant is moved and arranged on the surface of the coating film (interface with the atmosphere). Using this movement as a driving force, the filler (B) is also the outermost surface. It is thought that it becomes easy to form unevenness of the filler on the surface at the same time.

≪Basic surfactant≫
The basic surfactant is a surfactant having a basic group in the molecule. Examples of the basic group include an amine group, amino group, amide group, pyrrolidone group, imine group, imino group, urethane group, A quaternary ammonium group, an ammonium group, a pyridino group, a pyridium group, an imidazolino group, an imidazolium group, and the like can be given.
As the basic surfactant, commercially available products can be used. Specifically, for example, SOLPERSE series 13240, 13940, 24000SC, 24000GR, 26000, 31845, 32000, 32500, 32550, 34750, 35100, 35200, 37500 (manufactured by Nippon Lubrizol Corporation), Azisper PB821, PB822, PB881 (manufactured by Ajinomoto Co., Inc.) and the like.

≪Fluorosurfactant≫
The fluorine-based surfactant is a surfactant containing fluorine, and examples thereof include a compound having a fluoroalkyl group and / or a fluoroalkylene group in at least one of the terminal, main chain and side chain.
Commercially available products can be used as the fluorosurfactant. Specifically, for example, BM-1000, BM-1100 (above, manufactured by BM CHEMIE), MegaFuck F142D, F172, F173, F183, F178, F191, F191, F471, F476 (above, manufactured by Dainippon Ink & Chemicals, Inc.), FT-100, FT-110, FT-140A, FT-150, FT-250 FT-251; FT-300; FT-310; FT-400S; FTX-218; FT-251 (above, manufactured by Neos).

  The content of the surfactant (E) is 100 parts by mass of the polyfunctional (meth) acrylic compound (A) because the anti-blocking effect of the obtained coating film is more excellent and the appearance is improved. On the other hand, 0.0001-5 mass parts is preferable, 0.01-5 mass parts is more preferable, 0.03-1 mass part is further more preferable.

<(Meth) acrylic polymer (F)>
The (meth) acrylic polymer (F) will be described below.
The (meth) acrylic polymer (F) contained in the composition of the present invention has a weight average molecular weight of 10,000 to 100,000, and has 70% by mass or more of methyl (meth) acrylate units per molecule. It is a polymer of (meth) acrylate.
The (meth) acrylic polymer (F) contains at least a methyl (meth) acrylate unit (a repeating unit composed of methyl (meth) acrylate).
The (meth) acrylic polymer (F) may be either a homopolymer or a copolymer. The (meth) acrylic polymer (F) is a preferred embodiment that is a homopolymer.

When the (meth) acrylic polymer (F) is a copolymer, the structural unit that the (meth) acrylic polymer (F) can further contain other than the methyl (meth) acrylate unit is not particularly limited. Examples thereof include aromatic vinyl units; alkyl (meth) acrylate units other than methyl (meth) acrylate units (for example, butyl (meth) acrylate units). Especially, it is preferable that a (meth) acrylic polymer (F) contains an aromatic vinyl unit further from a viewpoint that it is excellent in an optical characteristic and a coating-film external appearance.
Examples of the aromatic vinyl unit include compounds derived from a compound having a carboxyl group such as styrene, alkylstyrene, and vinyl benzoic acid, and aromatic vinyl compounds such as divinylbenzene. Among these, it is preferable to further include a styrene unit.

  The structural unit (repeating unit) that can constitute the (meth) acrylic polymer (F) includes the methyl (meth) acrylate unit, an alkyl (meth) acrylate unit other than the methyl (meth) acrylate unit, and the aromatic vinyl. In addition to the unit derived from the compound, for example, (meth) acrylates other than those described above; (meth) acrylic acid; those derived from acrylonitrile are exemplified.

The weight average molecular weight of the (meth) acrylic polymer (F) is preferably 15,000 to 80,000, and preferably 20,000 to 75,000, from the viewpoint of excellent optical properties and coating film appearance. More preferred.
In the present invention, the weight average molecular weight is a standard polystyrene equivalent value based on a measured value by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent.

In the present invention, the content of the methyl (meth) acrylate unit per molecule of the (meth) acrylic polymer (F) is 70% by mass or more, and 70 to 100 from the viewpoint of excellent optical properties and coating film appearance. It is preferable that it is mass%, and it is more preferable that it is 80-100 mass%.
In the present invention, when the (meth) acrylic polymer (F) is a copolymer, the content of each structural unit (repeating unit) constituting the (meth) acrylic polymer (F) is determined by ¹ H-NMR analysis, ¹³ C- It was calculated from the results of NMR analysis and IR analysis.

The (meth) acrylic polymer (F) does not have an unsaturated bond from the viewpoint of incompatibility with the filler (B), coating film appearance, and excellent haze (optical properties such as total light transmittance). Is mentioned as one of the preferred embodiments. Here, the (meth) acrylic polymer (F) is excellent in incompatibility with the filler (B), that is, the (meth) acrylic polymer (F) is hardly compatible with the filler (B). ) Are easily separated from the system, and the filler (B) is likely to be easily oriented (or arranged) on the cured film (hard coat layer) formed by the composition of the present invention.
The (meth) acrylic polymer (F) is not particularly limited for its production. For example, a conventionally well-known thing is mentioned.

  The content of the (meth) acrylic polymer (F) is 1 to 20 parts by mass with respect to 100 parts by mass of the polyfunctional (meth) acrylic compound (A) from the viewpoint of excellent optical characteristics and coating film appearance. Is more preferable, 1 to 15 parts by mass is more preferable, 2.5 to 12.5 parts by mass is still more preferable, and 5 to 10 parts by mass is particularly preferable.

  In the composition of the present invention, in addition to the above essential components, for example, an antioxidant, an antistatic agent, a flame retardant, an adhesion-imparting agent, a dispersant, an antioxidant, and an antifoam, as long as the object of the present invention is not impaired. It can further contain additives such as agents, matting agents, light stabilizers, dyes, pigments.

  The production method of the composition of the present invention is not particularly limited, and examples thereof include a method in which the above-described essential components and optional components are placed in a reaction vessel and sufficiently mixed using a stirrer such as a mixing mixer under reduced pressure. .

The composition of the present invention (the composition for forming a hard coat layer) is applied on at least one side of the substrate and then cured to form a hard coat layer as a coating film, and the hard coat layer is formed on at least one side of the substrate. A laminate provided with a coat layer can be obtained.
Examples of the substrate include, but are not limited to, a film made of polyethylene terephthalate (PET) or the like. The thickness of the substrate can be about 10 to 300 μm.
The method for applying the composition of the present invention is not particularly limited, and for example, known application methods such as brush coating, flow coating, dip coating, spray coating, and spin coating can be employed.
Although it does not specifically limit as an application quantity of the composition of this invention, For example, the quantity from which the thickness of the hard-coat layer after hardening is set to about 1-10 micrometers is mentioned.
The composition of the present invention can be cured by, for example, ultraviolet rays. Although it does not specifically limit as an irradiation amount of the ultraviolet-ray used when hardening the composition of this invention, From a viewpoint of quick curability and workability | operativity, for example, 50-3000mJ / cm < ² > is mentioned, 100-3000mJ / cm ² is preferred. The temperature at which the composition of the present invention is cured by ultraviolet irradiation can be, for example, 20 to 110 ° C, and preferably 20 to 80 ° C. The apparatus for irradiating ultraviolet rays is not particularly limited, and a conventionally known apparatus can be used.

Next, a laminate using the composition of the present invention (hard coat layer forming composition) will be described in detail with reference to the accompanying drawings. The present invention is not limited to the attached drawings.
FIG. 1 is a cross-sectional view schematically showing an example of a laminate having a hard coat layer formed using the composition for forming a hard coat layer of the present invention.

As shown in FIG. 1, the laminate 1 has a substrate 11 such as a PET film. On one surface (upper surface) of the base material 11, a hard coat layer 13 which is a coating film obtained by curing the composition of the present invention is formed. The thickness of the hard coat layer 13 is, for example, about 1 to 10 μm. Note that a hard coat layer (not shown) may be formed on the other surface (lower surface) of the substrate 11.
As shown in FIG. 1, an ITO layer 17 serving as an electrode is formed on the upper side of the hard coat layer 13 via an index matching layer 15 having a thickness of about 10 to 500 nm, for example. The index matching layer 15 is a layer for making it difficult to see the conductive pattern of the ITO layer 17 after the etching process, and the refractive index matching layer 15 a having a refractive index higher than that of the ITO layer 17 and the refractive index higher than that of the ITO layer 17. Of the low bending index matching layer 15b.

In this invention, a laminated body is used for thin electronic devices, such as a touch panel apparatus, for example, and can comprise the component of an electronic device.
The laminate may be wound or stacked in the production process. At this time, the hard coat layer is a coating film obtained by curing the composition of the present invention. Since it is excellent in property, sticking is prevented and in-process defects can be suppressed. Moreover, since a hard-coat layer is a coating film obtained by hardening the composition of this invention, a refractive index is adjusted and it can have a refractive index comparable as a base material.

  The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these.

[Production of hard coat layer forming composition]
The components shown in Table 1 below were used in the amounts (parts by mass) shown in the same table, and these were mixed to produce a composition for forming a hard coat layer (hereinafter also simply referred to as “composition”).
In addition, about the wet filler about (B) component, the net quantity of the filler was described in Table 1. For other components as well, the net amount of each component was similarly described.

[Formation of coating film (production of laminate)]
The composition produced as described above was placed on a PET film (trade name: Lumirror U-403, manufactured by Toray Industries, Inc., thickness: 125 μm) as a base material with a bar coater no. 5 (film thickness: adjusted to 2 to 3 μm), and then dried at 80 ° C. for 1 minute, and the composition was irradiated with ultraviolet rays (UV) under the conditions of 400 mW / cm ² and 400 mJ / cm ^2. Was cured by irradiation to produce a laminate in which a coating film (hard coat layer) was formed on the PET film.

[Evaluation]
The following evaluation was performed using the laminate manufactured as described above. The results are shown in Table 1 below.

[Film properties]
<Total light transmittance>
Using a haze meter (HM-150, manufactured by Murakami Color Research Laboratory), the total light transmittance of the laminate produced as described above was measured according to JIS K7361.

<Haze>
Using a haze meter (HM-150, manufactured by Murakami Color Research Laboratory), the haze of the laminate produced as described above was measured according to JIS K7105. The haze is preferably 2.0% or less.

<Anti-block property>
First, a plurality of individual samples (50 mm × 50 mm) were cut out from the laminate manufactured as described above. Next, the two individual samples are stacked so that the hard coat layer of one individual sample and the PET film of the other individual sample are in contact with each other, and these are sandwiched between the thumb and index finger of a human hand. The antiblock property was evaluated by rubbing.
The evaluation standard of anti-blocking property was evaluated as “A” because the case where two individual samples did not stick together and slid well with each other was considered excellent in anti-blocking property.
Anti-blocking property when two pieces of individual samples are stuck, but when two pieces of individual samples are rubbed strongly several times (5 times or less), the two pieces of samples are peeled off and begin to slide Was evaluated as “B”.
Even if two pieces of individual samples are stuck and they are rubbed together several times (six times or more), the case where the two pieces of samples remain stuck is evaluated as “C” as being inferior in anti-blocking property. did.
If it is "A" or "B", it can be evaluated as having excellent antiblocking properties.

<Refractive index>
About the laminated body manufactured as mentioned above, the refractive index in D line 589.6nm of the spectrum of sodium was measured by the measuring method based on JISK7105: 1981 using the ATAGO Abbereflectometer (measuring range: 1). .3-1.71).
As for the refractive index, the refractive index (upper) on the coating film surface of the laminate is preferably 1.63 to 1.67. The refractive index (lower) on the PET base material side is preferably 1.49 to 1.55.

[Appearance of coating film]
<Color tone>
The appearance of the laminate produced as described above was confirmed visually.
When the color tone of the laminate was colorless and transparent, it was evaluated as “A” because it was excellent in color tone.
When the color tone of the laminate was white and / or when the laminate was turbid, it was evaluated as “B” because the color tone was inferior.

<Streak>
When there was no streak in the laminate, it was evaluated as “A” because it was excellent in the appearance of the coating film.
When there was a streak, it was evaluated as “B” because the appearance of the coating film was inferior.

<Butt / Repel>
In the case where the laminate did not have irregularities (aggregated particles) and repellency, it was evaluated as “A” because the appearance of the coating film was excellent.
When the laminate had irregularities and / or repellency, it was evaluated as “B” because the appearance of the coating film was inferior.

The details of each component shown in Table 1 are as follows.
Urethane acrylate: urethane acrylate obtained by reacting hexamethylene diisocyanate (HDI) and dipentaerythritol pentaacrylate (DPPA) (equivalent ratio of isocyanate group concentration in HDI to total active hydrogen group concentration in DPPA (NCO / Active hydrogen group) = 0.6, weight average molecular weight: 944, number of acryloyloxy groups in one molecule: 8-10)
-Aromatic ring-containing acrylate: Ogsol EA-HC936 (fluorene-containing acrylate, Osaka Gas Chemical Co., Ltd., weight average molecular weight: 689, number of acryloyloxy groups in one molecule: 4)

Zirconium oxide 1: wet zirconium oxide, MEK dispersion, average primary particle size: 20 nm, modified by (meth) acryloyloxy group Barium titanate 1: wet barium titanate, MIBK dispersion, average primary particle size: 30 nm Modified by (meth) acryloyloxy group Comparative barium titanate 1: dry barium titanate, average primary particle size: 150 nm, modified by (meth) acryloyloxy group Barium titanate 2: dry barium titanate Average primary particle size: 50 nm, no modification by (meth) acryloyloxy group Barium titanate 3: wet barium titanate, n-butanol dispersion, average primary particle size: 30 nm, no modification by (meth) acryloyloxy group

-Photopolymerization initiator: Irgacure 184 (manufactured by BASF Japan)
-Organic solvent: cyclohexanone-Surfactant 1: Fluorine-based surfactant, Footgent FTX-218 (manufactured by Neos)
Surfactant 2: Basic surfactant, SOLPERSE 32500 (manufactured by Nippon Lubrizol)

(Meth) acrylic polymer 1: polymethyl methacrylate (PMMA) having a weight average molecular weight of 65,000, Delpet 720V (manufactured by Asahi Kasei Chemicals)
-(Meth) acrylic polymer 2: methyl methacrylate-styrene copolymer having a weight average molecular weight of 19,000 (MMA / St = 80/20, mass ratio)
-(Meth) acrylic polymer 3: methyl methacrylate-butyl acrylate copolymer having a weight average molecular weight of 20,000 (20,000) (MMA / BA = 80/20, mass ratio)
Comparative (meth) acrylic polymer 1: polymethyl methacrylate having a weight average molecular weight of 8,000 Comparative (meth) acrylic polymer 2: methyl methacrylate-styrene-butyl acrylate copolymer having a weight average molecular weight of 22,000 (MMA / (St / BA = 56/10/34, weight ratio)

  As is clear from the results shown in Table 1, Comparative Examples 1 to 3 in which the average primary particle diameter of the filler exceeded 100 nm were inferior in antiblock properties. In addition, the appearance of the coating film was fuzzy and / or repelled. Comparative Example 4 in which the weight average molecular weight of the (meth) acrylic polymer was less than 10,000 was inferior in antiblock property. Comparative Example 5 in which the methyl (meth) acrylate unit per molecule of (meth) acrylic polymer was less than 70% by mass and Comparative Example 6 not containing (meth) acrylic polymer (F) were inferior in antiblock properties.

On the other hand, Examples 1-13 were excellent in antiblock property. Moreover, since the transmittance was high and the haze was excellent, the coating film properties were excellent and the coating film appearance was excellent.
Moreover, when Examples 1, 3, and 4 were compared about polyfunctional (meth) acrylic compound (A), it was excellent in haze, so that content of the aromatic ring containing acrylate increased.
When Examples 1 to 8 (Yes) and Examples 9 to 10 (No) are compared with respect to the presence or absence of the (meth) acryloyloxy group on the surface of the filler (B), Examples 1 to 8 are more than Examples 9 to 10. Also has high permeability and excellent haze. Further, when Example 5 and Examples 9 and 10 are compared, Example 5 has higher permeability and better haze than Examples 9 and 10, and at least one of anti-blocking property and coating film appearance is more excellent. .
When Example 3 (zirconium oxide) and Example 5 (barium titanate) were compared about the kind of filler (B), Example 5 was superior to Example 3 in haze.
When Example 3 (fluorinated surfactant) and Example 8 (basic surfactant) were compared for the type of surfactant (E), Example 3 was superior to Example 8 in antiblocking properties.
Example 7 (copolymer with styrene, Mw 19,000) and Example 11 (copolymer with butyl acrylate, Mw 20,000) when the (meth) acrylic polymer (F) is a copolymer In comparison, Example 7 had higher transmittance than Example 11, and was excellent in haze, antiblock property, and coating film appearance.
When comparing Examples 12 and 13 with respect to the mass ratio of aromatic ring-containing (meth) acrylate and urethane (meth) acrylate (aromatic ring-containing (meth) acrylate: urethane (meth) acrylate), aromatic ring-containing (meth) acrylate It was found that Example 13, which has a higher mass ratio, has a higher refractive index than Example 12.

1: Laminated body 11: Base material 13: Hard coat layer 15: Index matching layer 15a: High bending index matching layer 15b: Low bending index matching layer 17: ITO layer (conductive pattern)
20: Hard coat layer 22: Cross section of hard coat layer 22: Surface of hard coat layer 22: Filler (B)

Claims (7)

A polyfunctional (meth) acrylic compound (A) having two or more (meth) acryloyloxy groups in one molecule;
As the filler (B), barium titanate and / or zirconium oxide having an average primary particle size of 100 nm or less,
A photopolymerization initiator (C);
An organic solvent (D),
Surfactant (E),
A composition for forming a hard coat layer, comprising a (meth) acrylic polymer (F) having a weight average molecular weight of 10,000 to 100,000 and having 70% by mass or more of methyl (meth) acrylate units per molecule.   The composition for forming a hard coat layer according to claim 1, wherein the polyfunctional (meth) acrylic compound (A) further has an aromatic ring and / or a urethane bond in one molecule.   The composition for forming a hard coat layer according to claim 1 or 2, wherein the surfactant (E) is a fluorosurfactant.   Hard in any one of Claims 1-3 whose content of the said (meth) acrylic polymer (F) is 1-20 mass parts with respect to 100 mass parts of said polyfunctional (meth) acrylic compounds (A). A composition for forming a coat layer.   The composition for hard-coat layer formation in any one of Claims 1-4 in which the said filler (B) has a (meth) acryloyloxy group on the surface.   The composition for forming a hard coat layer according to any one of claims 1 to 5, wherein the (meth) acrylic polymer (F) further has a styrene unit.   The composition for forming a hard coat layer according to any one of claims 1 to 6, wherein the polyfunctional (meth) acrylic compound (A) has three or more of the (meth) acryloyloxy groups in one molecule.