Coating composition and laminate

Abstract

To provide a coating composition for forming a primer layer that exhibits excellent adhesion between the primer layer and the inorganic oxide layer, as well as superior scratch resistance of the primer layer surface, high light transmittance, low haze, no appearance defects, and minimal interference unevenness, warping, and changes in adhesion after boiling tests. [Solution] A coating composition for forming a primer layer on which a primer layer with a film thickness of 5 μm formed from the coating composition is laminated, wherein the primer layer has a haze value of 1% or less, and the substrate is laminated with a primer layer with a film thickness of 5 μm. The polymerizable compound (A) contains a polymerizable compound (A) and silica particles (B) having (meth)acryloyl groups with an average particle size of 2 to 150 nm, wherein the polymerizable compound (A) contains at least one of a trifunctional or more urethane (meth)acrylate (a1) and a trifunctional or more (meth)acrylate (a2), and a (meth)acrylate (a3) ​​having a refractive index of 1.50 or more, and the silica particles (B) are contained in an amount of 130 to 350 parts by mass per 100 parts by mass of polymerizable compound (A).

Description

Technical Field

[0001] The present invention relates to a coating composition and a laminate for forming a primer layer disposed between a substrate and an inorganic oxide layer.

Background Art

[0002] Plastic substrates made of polyethylene terephthalate (PET) resin or the like are used in various applications because they are excellent in transparency and impact resistance, lightweight, and easy to process. However, since plastic substrates are inferior in surface properties such as hardness and scratch resistance compared to glass substrates, it has been considered to form a primer layer on the surface of the plastic substrate and further laminate an inorganic substance layer thereon to form a laminate and improve the surface properties of the plastic substrate.

[0003] Thus, by laminating an inorganic substance layer on the primer layer, surface properties such as hardness and scratch resistance have been improved, and it has been proposed to use silica particles in the primer layer to improve the adhesion to the inorganic substance layer (see Patent Documents 1 and 2), but the adhesion between the primer layer and the inorganic substance layer is still not satisfactory. Further, in Patent Document 2, a hard coat layer with a thickness of 10 μm is formed on both sides of a film substrate containing a fumaric acid diester-based resin to suppress warping of the film, but when a hard coat layer is formed on one side of a thinner substrate, warping of the film is likely to occur, so a laminate with little warping is required.

[0004] A laminate in which an inorganic substance layer is laminated on a primer layer is used for touch panel members such as mobile phones and notebook computers, but in recent years, the opportunity to use it in outdoor and automotive interior members has increased. Therefore, it is required that the adhesion and the like of the laminate are not deteriorated even when it is exposed to a harsh environment such as high temperature and high humidity for a long time.

[0005] In recent years, these products have also been used in high-temperature and high-humidity environments such as bathrooms, and there is a growing demand for boil-resistant properties that do not reduce the adhesion of the laminate even after being boiled in boiling water (100°C), which is an even more severe condition.

[0006] However, with conventional coating compositions, it is difficult to suppress the decrease in adhesion and other properties after boiling tests, and there are also issues with warping when a hard coat layer is formed on only one side of the substrate. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2018-058234 [Patent Document 2] Japanese Patent Publication No. 2019-131664 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The problem that the present invention aims to solve is to provide a coating composition for forming a primer layer that exhibits excellent adhesion between the primer layer and the inorganic oxide layer, excellent scratch resistance of the primer layer surface, high light transmittance of the primer layer, low haze, no appearance defects, minimal interference unevenness and warping, and minimal changes in adhesion, etc., even after boiling tests. Furthermore, the present invention aims to provide a laminate having a primer layer formed from the coating composition. [Means for solving the problem]

[0009] The inventors of this invention have conducted extensive research to solve the above problems and have arrived at the following inventions [1] to [5].

[0010] [1] A coating composition for forming a primer layer to be disposed between a substrate and an inorganic oxide layer, wherein the coating composition contains a polymerizable compound (A) and silica particles (B) having (meth)acryloyl groups with an average particle size of 2 to 150 nm, The polymerizable compound (A) comprises at least one of a trifunctional or more urethane (meth)acrylate (a1) and a trifunctional or more (meth)acrylate (a2), and a (meth)acrylate (a3) ​​having a refractive index of 1.50 or more, the silica particles (B) content is 130 to 350 parts by mass per 100 parts by mass of the polymerizable compound (A), and the haze value of the substrate on which a primer layer with a film thickness of 5 μm formed from the coating composition is laminated is 1% or less. However, the three- or more functional urethane (meth)acrylate (a1) and the three- or more functional (meth)acrylate (a2) exclude (meth)acrylate (a3) ​​with a refractive index of 1.50 or higher, and the three- or more functional (meth)acrylate (a2) excludes urethane (meth)acrylate (a1).

[0011] [2] The coating composition having a fluorene skeleton in (meth)acrylate (a3) ​​with a refractive index of 1.50 or higher.

[0012] [3] The coating composition wherein the content of trifunctional or more urethane (meth)acrylate (a1) is 10 to 80% by mass of 100% by mass of the polymerizable compound (A).

[0013] [4] The coating composition wherein the trifunctional or more urethane (meth)acrylate (a1) has an alicyclic structure.

[0014] [5] A laminate in which at least a substrate, a primer layer formed by the above coating composition, and an inorganic oxide layer are arranged in this order. [Effects of the Invention]

[0015] The present invention makes it possible to provide a coating composition for forming a primer layer that exhibits excellent adhesion between the primer layer and the inorganic oxide layer, excellent scratch resistance of the primer layer surface, high light transmittance of the primer layer, low haze, no appearance defects, minimal interference unevenness and warping, and minimal changes in adhesion, etc., even after boiling tests. Furthermore, it is possible to provide a laminate having a primer layer formed from the coating composition. [Modes for carrying out the invention]

[0016] The details of the present invention will be described below. It goes without saying that other embodiments are also included within the scope of the present invention, as long as they are consistent with the spirit of the invention. First, we will explain the symbols, abbreviations, and terminology used in this specification. A numerical range specified using "~" includes the numbers written before and after "~" as the lower and upper limits. "nD25" represents the refractive index measured at 25°C using the sodium D line as the light source. "Mn" represents the number-average molecular weight obtained by the method described in the examples.

[0017] In this specification, unless otherwise specified, "(meth)acrylic," "(meth)acryloyl," and "(meth)acrylate" refer to "acrylic or methacrylic," "acryloyl or methacryloyl," and "acrylate or methacrylate," respectively. Furthermore, "polymerizable compound (A)" may be abbreviated as "compound (A)", "trifunctional or more urethane (meth)acrylate (a1)" as "(meth)acrylate (a1)", "trifunctional or more (meth)acrylate (a2)" as "(meth)acrylate (a2)", "(meth)acrylate (a3) ​​with a refractive index of 1.50 or higher" as "(meth)acrylate (a3)", and "silica particles having (meth)acryloyl groups with an average particle size of 2 to 150 nm (B)" as "silica particles (B)". Unless otherwise noted, the various components appearing in this specification may be used independently one by one or in combination of two or more.

[0018] ≪Coating Composition≫ The coating composition of the present invention contains a polymerizable compound (A) and silica particles (B), the polymerizable compound (A) includes at least one of (meth)acrylate (a1) and (meth)acrylate (a2), and (meth)acrylate (a3), the content of the silica particles (B) is 130 to 350 parts by mass with respect to 100 parts by mass of the polymerizable compound (A), and the haze value of a substrate laminated with a primer layer having a film thickness of 5 μm formed from the coating composition is 1% or less.

[0019] <Polymerizable Compound (A)> The polymerizable compound (A) includes at least one of (meth)acrylate (a1) and (meth)acrylate (a2), and (meth)acrylate (a3). By including these, the primer layer surface has excellent scratch resistance, the refractive index difference between the substrate and the primer layer is reduced, interference unevenness is also reduced, and furthermore, a primer layer with high light transmittance and low haze can be obtained.

[0020] <Trifunctional or higher urethane (meth)acrylate (a1)> Examples of the (meth)acrylate (a1) include those obtained by reacting a diisocyanate with (meth)acrylates having a hydroxyl group, those obtained by reacting a polyol and a polyisocyanate under conditions of excess isocyanate groups to form an isocyanate group-containing urethane prepolymer and then reacting it with a (meth)acrylate having a hydroxyl group, and those obtained by reacting a polyol and a polyisocyanate under conditions of excess hydroxyl groups to form a hydroxyl group-containing urethane prepolymer and then reacting it with (meth)acrylates having an isocyanate group.

[0021] Examples of the polyisocyanate include aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates. Examples of aromatic diisocyanates include 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate (hereinafter abbreviated as MDI), 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl isocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, m-tetramethylxylylene diisocyanate, 4,4-diphenylmethane diisocyanate, xylylene diisocyanate, and 2,6-diisocyanate-benzyl chloride.

[0022] Examples of aliphatic diisocyanates include butane-1,4-diisocyanate, hexamethylene diisocyanate (HDI), isopropyl diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate.

[0023] Examples of alicyclic diisocyanates include cyclohexane-1,4-diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate (IPDI), dimmeryl diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, hydrogenated 4,4'-diphenylmethane diisocyanate (hereinafter abbreviated as hydrogenated MDI), 1,3-bis(isocyanate methyl)cyclohexane, methylcyclohexane diisocyanate, and norbornane diisocyanate. Other polyisocyanates mentioned above include dimer isocyanates, which are obtained by converting the carboxyl group of a dimer acid to an isocyanate group, as well as their dimers and trimers (isocyanurates), adducts and biuret compounds obtained by adding them to polyhydric alcohols.

[0024] Among polyisocyanates, alicyclic polyisocyanates such as cyclohexane-1,4-diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, dimethylyl diisocyanate, dicyclohexylmethane-4,4'-diisocyanate (hydrogenated 4,4'-diphenyldimethylmethane diisocyanate), 1,3-bis(isocyanate methyl)cyclohexane, methylcyclohexane diisocyanate, and norbornane diisocyanate are preferred in terms of suppressing yellowing, adhesion to inorganic oxide layers, and heat resistance to thermal history from boiling tests.

[0025] Examples of the above polyols include ethylene glycol, propylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, butylene glycol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-methyl-1,8-octanediol, 3,3'-dimethylolheptane, 2-butyl-2-ethyl-1,3-propanediol, polyoxyethylene glycol (additional moles of 10 or less), polyoxypropylene glycol (additional moles of 10 or less), propanediol, 1,3-butanediol, and 1,4-butanediol. Examples of aliphatic or alicyclic diols include polytetramethylene glycol (number of added moles 10 or less), Mitsubishi Chemical's PTMG250 (average number of added moles 2.9, molecular weight 225, PTMG250), 1,5-pentanediol, 1,6-hexanediol (1,6HD), 1,9-nonanediol, neopentyl glycol, octanediol, butylethylpentanediol, 2-ethyl-1,3-hexanediol, 1,4-cyclohexanediol (CHDM), cyclohexanedimethanol, tricyclodecanedimethanol, cyclopentadienedimethanol, and dimergol.

[0026] Other examples include polyols containing three or more hydroxyl groups, such as glycerin, trimethylolpropane, pentaerythritol, and dipentaerythritol.

[0027] Of the polyols mentioned above, branched alkanediols such as neopentyl glycol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-methyl-1,8-octanediol, 3,3'-dimethylolheptane, 2-butyl-2-ethyl-1,3-propanediol, butylethylpentanediol, 2-ethyl-1,3-hexanediol, and trimethylolpropane, and alicyclic diols such as cyclohexanediol, cyclohexanedimethanol, tricyclodecanedimethanol, cyclopentadienedimethanol, and dimergol are preferred in terms of adhesion and heat resistance to heat history from boiling tests, and alicyclic diols such as cyclohexanediol, cyclohexanedimethanol, tricyclodecanedimethanol, cyclopentadienedimethanol, and dimergol are more preferred in terms of adhesion to the inorganic oxide layer.

[0028] Furthermore, the above-mentioned (meth)acrylates having hydroxyl groups include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate (hereinafter, 4-hydroxybutyl acrylate may be abbreviated as 4-HBA), ethylene glycol mono(meth)acrylate, diethylene glycol mono(meth)acrylate, triethylene glycol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 1,3-butanediol mono(meth)acrylate, 1,4-butanediol mono(meth)acrylate, polytetramethylene glycol mono(meth)acrylate, polyethylene glycol-polypropylene glycol mono(meth)acrylate, polyethylene glycol-polybutylene glycol mono(meth)acrylate Neopentyl glycol mono(meth)acrylate, 1,6-hexanediol mono(meth)acrylate, hydroxypivalate neopentyl glycol mono(meth)acrylate, polycaprolactone (meth)acrylate (compounds with terminal hydroxyl groups obtained by ring-opening polymerization of ε-caprolactone with acrylic acid, such as Daicel's Praxel FA4DT (molecular weight 573)), bisphenol A mono(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane di(meth)acrylate Examples include lylate, pentaerythritol mono(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate (sometimes abbreviated as PE-3A), dipentaerythritol penta(meth)acrylate (sometimes abbreviated as DPE-5A), dipentaerythritol tetra(meth)acrylate, 4,4'-cyclohexyldimethanol mono(meth)acrylate, tricyclodecanedimethanol mono(meth)acrylate, glycerol(meth)acrylate, etc.

[0029] The number of functional groups in (meth)acrylate (a1) (where "number of functional groups" refers to the number of (meth)acryloyl groups in one molecule) may be three or more, but from the viewpoint of suppressing warping and changes in haze value after boiling tests, it is preferable to have 15 or fewer, and more preferably 9 or fewer.

[0030] The Mn content of (meth)acrylate (a1) is preferably 500 to 5000, and more preferably 1000 to 4000, from the viewpoint of suppressing warping and changes in haze value after boiling tests.

[0031] (Meth)acrylate (a1) is preferably (meth)acrylate (a1) has a branched structure or an alicyclic structure from the viewpoint of suppressing warping, changes in haze value after boiling test, adhesion, and heat resistance to thermal history due to boiling test, and is more preferably (meth)acrylate (a1) has an alicyclic structure from the viewpoint of adhesion with the inorganic oxide layer.

[0032] <(meth)acrylate (a2) with three or more functional properties> Examples of (meth)acrylate (a2) include polyol poly(meth)acrylate compounds such as trimethylolpropane triacrylate, glycerin triacrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate, as well as mixtures thereof.

[0033] <Refractive index of 1.50 or higher (meth)acrylate (a3)> Examples of (meth)acrylates (a3) ​​include phenoxybenzyl acrylate (PBA, molecular weight 254, refractive index 1.565 (nD25)), o-phenylphenol ethylene oxyacrylate (OPPEA, molecular weight 268, refractive index 1.577 (nD25)), 2-(phenylthio)ethyl acrylate (PTEA, molecular weight 208, refractive index 1.558 (nD25)), benzyl acrylate (BZA, molecular weight 162, refractive index 1.516 (nD25)), phenol ethylene oxyacrylate (PHEA, molecular weight 192, refractive index 1.517 (nD25)), phenol EO (ethylene oxide) 2 adduct acrylate (PHEA-2, molecular weight 236, refractive index 1.508 (nD25)), and phenol ethylene oxide 4 adduct acrylate (PHEA-4, molecular weight 324, refractive index 1.500 (nD 25)), aromatic (meth)monoacrylates such as benzyl methacrylate (BZMA, molecular weight 176, refractive index 1.512 (nD25)), phenoxy methacrylate (PHEMA, molecular weight 206, refractive index 1.510 (nD25)), polyalicyclic (meth)acrylates such as tricyclodecanedimethanol diacrylate (TCDDA, molecular weight 304, refractive index 1.503 (nD25)), diacrylate of bisphenol A ethylene oxide 3 adduct (BPA(EO)3DA, molecular weight 468, refractive index 1.545 (nD25)), diacrylate of bisphenol A EO4 adduct (BPA(EO)4DA, molecular weight 512, refractive index 1.537 (nD25)), diacrylate of bisphenol A EO10 adduct (BPA(EO)10DA, molecular weight 776, refractive index 1.516 (nD25)), bisphenol F Diacrylate of EO4 adduct (BPF(EO)4DA, molecular weight 499, refractive index 1.539 (nD25)), dimethacrylate of bisphenol A EO4 adduct (BPA(EO)4DMA, molecular weight 540, refractive index 1.529 (nD25)), dimethacrylate of bisphenol A EO3 adduct (BPA(EO)3DMA, molecular weight 496, refractive index 1.537 (nD25)), dimethacrylate of bisphenol A EO2 adduct (BPA(EO)2DMA, molecular weight 452, refractive index 1.542 (nD25)), dimethacrylate of bisphenol A EO10 adduct (BPA(EO)10DMA, molecular weight 804, refractive index 1.Examples include aromatic di(meth)acrylates such as 512(nD25) and bisphenol A EO17 adduct dimethacrylate (BPA(EO)17DMA, molecular weight 1112, refractive index 1.500(nD25)), aromatic epoxy(meth)acrylates, aromatic polyester(meth)acrylates, and aromatic di(meth)acrylates such as fluorene(meth)acrylates, as well as tris(2-hydroxyethyl) isocynurate triisocyanate (THEICTA, molecular weight 423, refractive index 1.508(nD25)).

[0034] From the viewpoint of refractive index, suppression of interference unevenness, and transparency, bisphenol-based di(meth)acrylates, bisphenol-based di(meth)epoxyacrylates, and fluorene-based di(meth)acrylates having multiple aromatic rings are preferred. In this specification, bisphenol fluorene-based di(meth)acrylate is a reaction product of 9,9-bis(4-hydroxyphenyl)fluorene and (meth)acrylic acid, and bisphenol fluorene (meth)epoxy (meth)acrylate is a reaction product of 9,9-bis(4-glycidyloxyphenyl)fluorene and (meth)acrylic acid, but may also have methyl groups, amino groups, or other ring structures, and is not necessarily limited to these. Note that "9,9-bis(4-hydroxyphenyl)fluorene" may be abbreviated as "bisfluorene".

[0035] Examples of bisphenol-based (meth)acrylates include diacrylate of bisphenol A EO3 adduct (BPA(EO)3 adduct DA, molecular weight 468, refractive index 1.545 (nD25)), diacrylate of bisphenol A EO4 adduct (BPA(EO)4 adduct DA, molecular weight 512, refractive index 1.537 (nD25)), diacrylate of bisphenol A EO10 adduct (BPA(EO)10DA, molecular weight 776, refractive index 1.516 (nD25)), diacrylate of bisphenol F EO4 adduct (BPF(EO)4DA, molecular weight 499, refractive index 1.539 (nD25)), dimethacrylate of bisphenol A EO4 adduct (BPA(EO)4DMA, molecular weight 540, refractive index 1.529 (nD25)), and bisphenol A Examples include dimethacrylate of EO3 adducts (BPA(EO)3DMA, molecular weight 496, refractive index 1.537 (nD25)), dimethacrylate of bisphenol A EO2 adducts (BPA(EO)2DMA, molecular weight 452, refractive index 1.542 (nD25)), dimethacrylate of bisphenol A EO10 adducts (BPA(EO)10DMA, molecular weight 804, refractive index 1.512 (nD25)), and dimethacrylate of bisphenol A EO17 adducts (BPA(EO)17DMA, molecular weight 1112, refractive index 1.500 (nD25)).

[0036] Examples of bisphenol-based epoxy (meth)acrylates include bisphenol A epoxy acrylate (difunctional acrylate, molecular weight 520, refractive index 1.557 (nD25)), phenol novolac epoxy acrylate (50% TMTPA, tetrafunctional acrylate, molecular weight 1400, refractive index 1.525), cresol novolac epoxy tetra(meth)acrylate (50% TMTPA, tetrafunctional acrylate, molecular weight 3000, refractive index 1.522 (nD25)), cresol novolac epoxy tetra(meth)acrylate (50% TMTPA, tetrafunctional acrylate, molecular weight 3000, refractive index 1.522 (nD25)), and other poly(meth)acrylate dilutions thereof.

[0037] Examples of bisphenol fluorene-based di(meth)acrylates include bisphenol fluorene EO2 adduct diacrylate (molecular weight 546, refractive index 1.60 (nD25)), bisphenol fluorene EO6 adduct diacrylate (molecular weight 723, refractive index 1.58 (nD25)), bisphenol fluorene EO10 adduct diacrylate (molecular weight 899, refractive index 1.562 (nD25)), and bisphenol fluorene EO20 adduct diacrylate (molecular weight 1350, refractive index 1.530 (nD25)).

[0038] Other examples include an octafunctional urethane acrylate obtained by reacting one molecule of bisphenol full orange epoxy compound with two molecules of acrylic acid, two molecules of aromatic diisocyanate compound, and two molecules of pentaerythritol triacrylate, as well as a hexafunctional urethane acrylate obtained by reacting a bisphenol full orange epoxy compound with two molecules of acrylic acid, two molecules of aromatic acid anhydride, two molecules of glycidyl methacrylate, and two molecules of 2-isocyanatoethyl acrylate.

[0039] Commercially available bisphenol fluorene-based di(meth)acrylates include: Osaka Gas Chemical's ORSOL EA-0200 (5% toluene, bifunctional acrylate, refractive index 1.616 (nD25)), ORSOL EA-O300 (bifunctional acrylate, refractive index 1.555 (nD25)), ORSOL GA-2800 (bifunctional epoxy acrylate, refractive index 1.550 (nD25)), ORSOL GA-5060P (40% PGMEA, bifunctional epoxy acrylate, refractive index 1.620 (nD25)), ORSOL EA-F5710 (containing m-phenoxybenzyl acrylate, bifunctional epoxy acrylate, refractive index 1.61 (nD25)), and MIWON's MIRAMER. HR6022 (a mixture of 65% by mass of bisphenol full orange acrylate (molecular weight 550, refractive index 1.600 (nD25)) and 35% of phenoxybenzyl acrylate (abbreviated as PBA, molecular weight 254, refractive index 1.565 (nD25))), MIRAMER HR6040 (a mixture of 70% by mass of bisphenol full orange acrylate (molecular weight 550, refractive index 1.600 (nD25)), 15% by mass of o-phenoxybenzyl EO-added acrylate (abbreviated as OPPEA, molecular weight 268, refractive index 1.577 (nD25), (a3-2)) and 15% by mass of PBA), MIRAMER Examples include HR6042 (a mixture of 60% by mass of EO-modified bisphenol full orange acrylate (abbreviated as BPFL(EO)DA, molecular weight 550, refractive index 1.600 (nD25)) and 40% by mass of o-phenoxybenzyl EO-added acrylate (abbreviated as OPPEA, molecular weight 268, refractive index 1.577 (nD25))), MIRAMER HR6060 (EO-modified bisphenol full orange acrylate, molecular weight 730, refractive index 1.584 (nD25)), MIRAMER HR6100 (EO-modified bisphenol full orange acrylate, abbreviated as BPFL(EO)DA, molecular weight 900, refractive index 1.562 (nD25)), MIRAMER HR6200 (EO-modified bisphenol full orange acrylate, abbreviated as BPFL(EO)DA, molecular weight 1350, refractive index (nD25)), etc.

[0040] Other (meth)acrylates (a3) ​​include MIRAMER M1142 (abbreviated as OPPEA, molecular weight 268, refractive index 1.577 (nD25)), MIRAMER M1122 (phenoxybenzyl acrylate, abbreviated as PBA, molecular weight 254, refractive index 1.577 (nD25)), MIRAMER M244 (bisphenol A ethylene oxide 3-addition diacrylate, abbreviated as BPA(EO)3DA, molecular weight 468, refractive index 1.545 (nD25)), and other aromatic acrylates other than fluorene-based ones, such as MIRAMER M262 (tricyclodecanedimethanol diacrylate, abbreviated as TCDDA, molecular weight 304, refractive index 1.503 (nD25)), and MIRAMER HR2582 (monofunctional urethane acrylate, molecular weight 650, refractive index 1.595 (nD25)), MIRAMER HR3200 (tetrafunctional urethane acrylate, molecular weight 900, refractive index 1.565 (nD25)), MIRAMER HR3700 (bifunctional urethane acrylate, molecular weight 800, refractive index 1.585 (nD25)), MIRAMER HR3800 (trifunctional urethane acrylate, molecular weight 1600, refractive index 1.573 (nD25)), MIRAMER HR3940 (trifunctional urethane acrylate, molecular weight 1000, refractive index 1.533 (nD25)), MIRAMER Urethane (meth)acrylates such as PU2050 (a mixture of 70% by mass of bifunctional urethane acrylate (molecular weight 14000, refractive index 1.501 (nD25)) and 30% by mass of isobornyl acrylate (abbreviated as IBOA, molecular weight 208, refractive index 1.474 (nD25))), butadiene acrylates such as MIRAMER MB1000 (bifunctional butadiene acrylate, molecular weight 30000, refractive index 1.504 (nD25)), polyester acrylates such as MIRAMER PS4500 (tetrafunctional polyester acrylate, molecular weight 3500, refractive index 1.503 (nD25)) from MIWON, MIRAMER PE10 (monofunctional epoxy acrylate, molecular weight 220, refractive index 1.525 (nD25)) from MIWON, MIRAMER PE2100P (50% PHEA, bifunctional epoxy acrylate, molecular weight 2500, refractive index 1.553 (nD25)), MIRAMER EA2255 (bifunctional epoxy acrylate, molecular weight 840, refractive index 1.536 (nD25)), MIRAMER EA2259 (bifunctional epoxy acrylate, molecular weight 840, refractive index 1.529 (nD25)), MIRAMER EA2280 (bifunctional epoxy acrylate, molecular weight 1600, refractive index 1.524 (nD25)), MIRAMER ME2010 (mixture of 60% by mass of bifunctional epoxy acrylate (molecular weight 6000, refractive index 1.538 (nD25)) and 40% by mass of IBOA), MIRAMER ME2010 (bifunctional epoxy acrylate, molecular weight 3000, refractive index 1.531 (nD25)), MIRAMER Examples of epoxy acrylates include PE2310 (bifunctional epoxy acrylate, molecular weight 1400, refractive index 1.518 (nD25)) and MIRAMER PE240 (bifunctional epoxy acrylate, molecular weight 600, refractive index 1.539 (nD25)).

[0041] Among the above, from the viewpoint of suppressing interference unevenness, a refractive index of (meth)acrylate (a3) ​​of 1.55 or more and 1.63 or less is more preferable.

[0042] The content of (meth)acrylate (a1) is preferably 10 to 90% by mass, and more preferably 45 to 75% by mass, of 100% by mass of polymerizable compound (A), from the viewpoint of scratch resistance and warping suppression. The content of (meth)acrylate (a2) is preferably 10 to 60% by mass, and more preferably 15 to 45% by mass, of 100% by mass of polymerizable compound (A), from the viewpoint of adhesion after boiling. The content of (meth)acrylate (a3) ​​is preferably 10 to 60% by mass, and more preferably 20 to 50% by mass, of 100% by mass of polymerizable compound (A), from the viewpoint of reducing interference unevenness.

[0043] <Other polymerizable compounds (a4)> The polymerizable compound (A) may also contain other polymerizable compounds (a4) depending on the performance to be imparted to the primer layer being formed. Among the other polymerizable compounds (a4), preferred ones are compounds having a (meth)acryloyl group, such as (meth)acrylic acid, (meth)acrylates with two or fewer functionalities, urethane acrylates with two or fewer functionalities, polyester acrylates, epoxy acrylates, and the like.

[0044] Examples of (meth)acrylates with two or fewer functions include methyl (meth)acrylate, ethyl (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, lauryl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, 2-(meth)acryloyloxyethyl acid phosphate and other ester compounds, styrene and α-methylene and other styrene compounds, γ-(meth)acryloxypropyltrimethoxysilane and γ-(meth)acryloxypropyltriethoxysilane and other silane compounds, and 2-(N,N-dimethyl Examples include nitrogen-containing compounds such as ethylaminoethyl (meth)acrylate, N-methylol(meth)acrylamide, diethyl(meth)acrylamide, N-vinyl-ε-caprolactam, and acryloylmorpholine; fluorine-containing compounds such as trifluoroethyl (meth)acrylate and 2,2,3,3,3-pentafluoropropyl (meth)acrylate; monofunctional (meth)acrylate compounds such as polymerizable silicone compounds in which the main chain of the polymer is a silicone component and one end is modified with a (meth)acrylate group; and bifunctional (meth)acrylate compounds such as polyethylene glycol diacrylate, polypropylene glycol diacrylate, hexanediol diacrylate, neopentyl glycol diacrylate, nonanediol diacrylate, bisphenol A diacrylate, bisphenol F diacrylate, and their ethylene oxy or propyl oxy modified forms.

[0045] Examples of urethane acrylates with two or fewer functionalities include those obtained in the same manner as the urethane (meth)acrylates with three or more functionalities, and having two or fewer (meth)acrylate groups.

[0046] <Silica particles (B) having (meth)acryloyl groups with an average particle size of 2-150 nm> Silica particles (B) refer to silica particles with an average particle size of 2 to 150 nm having (meth)acryloyl groups on their surface, or more specifically, silica particles with an average particle size of 2 to 150 nm that have been surface-treated with a silane coupling agent having (meth)acryloyl groups. Examples of silane coupling agents having (meth)acryloyl groups include 3-[(meth)acryloyloxy)propyl]trimethoxysilane and 3-[(meth)acryloyloxy)propyl]triethoxysilane. By containing a predetermined amount of silica particles (B) in the coating composition, the resulting primer layer exhibits excellent adhesion to the inorganic oxide layer, does not reduce light transmittance, and provides a primer layer with low haze. If the average particle size of the silica particles (B) is less than 2 nm, the area of ​​silica particles (B) exposed on the surface of the formed primer layer is small, and the effect of improving adhesion to the inorganic oxide layer cannot be obtained. On the other hand, if the average particle size of the silica particles (B) exceeds 150 nm, the surface area of ​​the primer layer does not become sufficiently large, and the effect of improving adhesion to the inorganic oxide layer cannot be obtained. Furthermore, light transmittance decreases, causing the formed primer layer to become cloudy. The average particle size of the silica particles (B) is preferably 2 to 90 nm, and particularly preferably 2 to 50 nm.

[0047] In this specification, the average particle size (MV) of silica particles (B) was determined based on values ​​measured from images observed by a transmission electron microscope (TEM). Specifically, using images (photographs) observed by TEM, the short axis diameter and long axis diameter of the primary particles of 100 silica particles (B) were measured, and the average of the short axis diameter and long axis diameter was taken as the particle size (d) of the silica particle (B). Then, assuming that each silica particle (B) is a sphere with the measured particle size, the volume (V) of each particle was calculated, and this process was performed for 100 silica particles (B). The volume-average particle size (MV) obtained from the following formula was taken as the average particle size (MV) of the silica particles (B). MV = Σ(V·d) / Σ(V)

[0048] The silica particle (B) content is 130 to 350 parts by mass, preferably 150 to 250 parts by mass, and more preferably 160 to 200 parts by mass, per 100 parts by mass of polymerizable compound (A). If the silica particle (B) content is less than 130 parts by mass, the effect of improving adhesion with the inorganic oxide layer cannot be obtained, and there is a risk that the haze value after boiling will be high. On the other hand, if the silica particle (B) content exceeds 350 parts by mass, the silica particle (B) tends to aggregate, which may reduce the light transmittance of the primer layer and increase the haze.

[0049] <Photopolymerization initiator> The coating composition of the present invention preferably contains a photopolymerization initiator. Examples of photopolymerization initiators that can be used include monocarbonyl photopolymerization initiators, dicarbonyl photopolymerization initiators, acetophenone photopolymerization initiators, benzoin ether photopolymerization initiators, acylphosphine oxide photopolymerization initiators, aminocarbonyl photopolymerization initiators, and the like. The photopolymerization initiator may be used in combination with a sensitizer.

[0050] Commercially available photopolymerization initiators include Omnirad 184, 651, 500, 907, 127, 369, 784, 2959, and ESACURE ONE from IGM-Resins BV, Lucilin TPO from BASF, and DAIDO UV-CURE #174 from Daido Chemical Industries, Ltd. From the viewpoint of resistance to yellowing after active energy ray curing, Omnirad 184, DAIDO UV-CURE #174, and ESACURE ONE are preferred.

[0051] From the viewpoint of curing speed, hardness of the primer layer, and scratch resistance, the photopolymerization initiator content is preferably 1 to 15% by mass, and more preferably 3 to 10% by mass, of 100% by mass of the nonvolatile content of the coating composition.

[0052] <Other ingredients> The coating composition of the present invention may optionally contain other components such as additives and organic solvents (D). Examples of additives include thermosetting resins, polymerization inhibitors, leveling agents (C), slip agents, defoaming agents, surfactants, antibacterial agents, antiblocking agents, plasticizers, ultraviolet absorbers, infrared absorbers, antioxidants, silane coupling agents, conductive agents, inorganic fillers, pigments, dyes, and the like.

[0053] <Leveling agent (C)> The coating composition may contain a leveling agent (C) depending on the performance to be imparted to the primer layer to be formed. The leveling agent is not particularly limited as long as it provides the desired leveling effect, i.e., an effect of suppressing coating defects such as repelling during coating, or an effect of smoothing the surface of the formed coating layer. Examples of such leveling agents include silicone-based leveling agents, fluorine-based leveling agents, acrylic-based leveling agents, siloxane-modified acrylic-based leveling agents, vinyl-based leveling agents, etc. The leveling agent may be used alone or in combination of two or more types. Among the above, acrylic-based leveling agents are preferred from the viewpoint of adhesion to the inorganic oxide layer.

[0054] <Organic solvent (D)> The coating composition of the present invention may contain an organic solvent (D). As the organic solvent (D), known organic solvents such as aromatic organic solvents such as toluene and xylene, ketone organic solvents such as methyl ethyl ketone and methyl isobutyl ketone, ester organic solvents such as ethyl acetate, propyl acetate, isopropyl acetate, isobutyl acetate, alcohol organic solvents such as methanol, ethanol, n-propanol, isopropanol, and n-butanol, and glycoether organic solvents such as propylene glycol monomethyl ether can be used. When an organic solvent (D) is included, from the viewpoint of coating properties and film-forming properties, it is preferable that the content of the organic solvent (D) is in the range of 1 to 60% by mass of the non-volatile content of the coating composition of the present invention.

[0055] <Primer layer> The primer layer can be formed in layers by applying the coating composition of the present invention and then curing it. When the coating composition of the present invention is an active energy ray curing type, the active energy ray can be ultraviolet light or an electron beam. Examples of ultraviolet light sources include high-pressure mercury lamps and metal halide lamps, and their irradiation energy is typically 100 to 2,000 mJ / cm². 2 It is approximately that level. Examples of electron beam supply methods include scan-type electron beam irradiation and curtain-type electron beam irradiation, and the irradiation energy is usually around 10 to 200 kGy.

[0056] <Laminate> The laminate of the present invention has a configuration in which a substrate, a primer layer formed by the coating composition of the present invention, and an inorganic oxide layer are arranged in this order. A configuration in which the substrate, primer layer, and inorganic oxide layer are laminated in this order is a preferred embodiment of the laminate. In this case, the laminate can be obtained by coating the substrate with the coating composition of the present invention, curing it to form a primer layer, and then forming an inorganic oxide layer. Apparatus for coating the surface of the substrate (one or both sides if the substrate is, for example, a film) with the coating composition includes sprayers, roll coaters, dip coaters, reverse roll coaters, gravure coaters, knife coaters, bar coaters, dot coaters, etc. The thickness of the primer layer is not particularly limited, but is preferably 1 to 30 μm, and more preferably 5 to 25 μm. If necessary, other layers may be placed between the substrate and the primer layer. Examples of other layers include, but are not limited to, an antistatic layer, a hard coat layer, and an anchor layer. <Base material> The substrate (also called the support) is not particularly limited and can be glass, synthetic resin molded products, or films. Examples of synthetic resin molded products include polymethyl methacrylate resin, copolymer resin mainly composed of methyl methacrylate, polystyrene resin, styrene-methyl methacrylate copolymer resin, styrene-acrylonitrile copolymer resin, polycarbonate resin, cellulose acetate butyrate resin, polyallyl diglycol carbonate resin, polyvinyl chloride resin, and polyester resin.

[0057] Examples of films include polyester film, polyethylene film, polyethylene terephthalate film, polypropylene film, cellophane film, diacetylcellulose film, triacetylcellulose (TAC) film, acetylcellulose butyrate film, polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene vinyl alcohol film, polyolefin film, polystyrene film, polycarbonate film, polymethylpentel film, polysulfone film, polyetheretherketone film, polyethersulfone film, polyetherimide film, polyimide film, fluororesin film, nylon film, and acrylic film.

[0058] <Inorganic oxide layer> The primer layer formed from the coating composition of the present invention exhibits excellent adhesion to the inorganic oxide layer. Therefore, when the primer layer and the inorganic oxide layer are directly laminated, peeling of the inorganic oxide layer can be suppressed. The inorganic oxide layer is preferably formed by a dry deposition method, and examples include vapor-deposited films, sputtered films, and CVD films, but vapor-deposited films or sputtered films are preferred. The thickness of the inorganic oxide layer is not particularly limited as long as it satisfies the physical, optical, and electrical properties, but it is usually 0.01 to 0.5 μm. The elements constituting the inorganic oxide layer include, but are not limited to, Si, Ti, Zn, Al, Ga, In, Ce, Bi, Sb, Zr, Sn, and Ta. The coating composition of the present invention is particularly effective when silicon dioxide is included in the inorganic oxide layer. [Examples]

[0059] The present invention will be described in more detail below with reference to examples and comparative examples, but the following examples do not limit the technical scope of the present invention in any way. Unless otherwise specified, "parts" refers to "parts by mass" and "%" refers to "mass percent". Unless otherwise specified, the blending amounts in the table refer to parts by mass, and for all except solvents, the values ​​are calculated on a non-volatile content basis. Blank spaces in the table indicate that the ingredient is not blended.

[0060] <Polymerizable compound (A)> <Measurement of the number-average molecular weight (Mn) of urethane acrylate> The manganese (Mn) content of the synthesized urethane acrylate was measured using a Tosoh HLC-8220GPC gel permeation chromatograph. Four Tosoh TSK-GEL SUPER H5000, TSK-GEL SUPER H4000, TSK-GEL SUPER H3000, and TSK-GEL SUPER H2000 columns were connected in series as separation columns. Tetrahydrofuran at 40°C was used as the mobile phase, and the manganese content was measured at a flow rate of 0.6 ml / min. From the resulting chromatograms, the manganese content was determined by converting polystyrene, whose manganese content is known, to a standard substance.

[0061] <Calculation of the molecular weight of polyisocyanates> Because the molecular weight of polyisocyanates is difficult to measure due to the influence of moisture and other factors, the number-average molecular weight of polyisocyanates was calculated using the following formula based on the number of isocyanate groups per molecule of polyisocyanate contained in the product (hereinafter abbreviated as NCO number), the mass percentage of isocyanate groups per molecule of polyisocyanate contained in the product (hereinafter abbreviated as NCO%), the non-volatile content (mass%) in the product, and the formula weight of the isocyanate groups (hereinafter abbreviated as NCO formula weight), as listed in the product catalog. If there was a range in the catalog values, the median value was used in the calculation. Molecular weight of polyisocyanate = (NCO molecular weight) × (NCO number) / (NCO%) × (non-volatile content%)

[0062] <Molecular weight of polyols> The molecular weight of the polyol was determined from the hydroxyl value, which was calculated according to JIS K0070:1992, using the following formula. Molecular weight of polyol = Number of hydroxyl groups in one polyol molecule / (Hydroxyl value of polyol (mgKOH / g) / 1000 / 56.11 (Molecular weight of potassium hydroxide))

[0063] <Measurement of average particle size of silica particles (B)> The average particle size (MV) of silica particles (B) was determined by measuring the short-axis and long-axis diameters of the primary particles of 100 silica particles (B) using images (photographs) observed with a transmission electron microscope (TEM, model H-7650, Hitachi High-Tech Corporation). The average of the short-axis and long-axis diameters was taken as the particle size (d) of the silica particle (B). Then, assuming that each silica particle (B) is a sphere with the determined particle size, the volume (V) of each particle was calculated. This process was repeated for 100 silica particles (B), and the volume-average particle size (MV) obtained from the following formula was taken as the average particle size (MV) of the silica particles (B). MV = Σ(V·d) / Σ(V)

[0064] Table 1 shows the raw materials used in the synthesis of (meth)acrylate (a1).

[0065] [Table 1]

[0066] <(meth)acrylate(a1)> (Synthesis Example 1) Production of Urethane Acrylate 1 (a1-1) In a flask equipped with a stirrer, reflux condenser, nitrogen inlet tube, thermometer, and dropping funnel, 1,6HD3 54.5 parts as polyol, 0.1 parts Neostan U-810 (tin catalyst, manufactured by Nitto Chemical Co., Ltd.), and 669.4 parts butyl acetate were added and heated to 50°C. Then, 1057.1 parts hydrogenated MDI as polyisocyanate were added dropwise through the dropping funnel over 30 minutes. After the temperature rise subsided, the temperature was increased to 80°C and the reaction was carried out for 3 hours. Fourier transform infrared absorption spectroscopy (FT-IR) showed an absorption peak (2250 cm⁻¹) originating from the isocyanate group. -1 The intensity of the peak appearing nearby was confirmed to have decreased to 1 / 4. Next, 6.5 parts of PE-3A5, a (meth)acrylate containing hydroxyl groups, were reacted at 80°C for 3 hours. After confirming that the peak originating from the isocyanate group had disappeared by FT-IR, butyl acetate was added while cooling to adjust the non-volatile content to 75%. A solution containing urethane acrylate 1(a1-1), which has a Mn of 2000 and 6 acryloyl groups per molecule, was obtained.

[0067] (Combination Example 2) ~ (Combination Example 15) Resin solutions 2 to 15 containing 75% urethane acrylate 2(a1-2) to urethane acrylate 15(a1-15) were obtained in the same manner as in Synthesis Example 1, except that the raw materials and blending amounts shown in Tables 2 and 3 were changed.

[0068] [Table 2]

[0069] [Table 3] <(meth)acrylate (a2), (meth)acrylate (a3), other polymerizable compounds (a4)> Table 4 shows the (meth)acrylate (a2), (meth)acrylate (a3), and other polymerizable compounds (a4) used in the examples and comparative examples. (Meth)acrylate (a3-9), a type of (meth)acrylate (a3), and urethane acrylate 16 (a4-2), a type of other polymerizable compound (a4), were prepared by the methods described in Synthesis Example 16 and Synthesis Example 17, respectively.

[0070] [Table 4]

[0071] <(Meth)acrylate (a3) ​​manufacturing> (Synthesis Example 16) Preparation of (meth)acrylate (a3-9, GMA2 adduct of PE-3A2 adduct of BPFA) In a flask equipped with a stirrer, reflux condenser, dry air inlet tube, and thermometer, 458.4 parts of 9,9-bis(3,4-dicarboxyphenyl)fluorenodioanhydride (manufactured by JFE Chemical Co., Ltd., molecular weight 458, trade name BPAF, abbreviated as BPAF), 596.6 parts of PE-3A, 0.45 parts of hydroquinone (manufactured by Wako Pure Chemical Industries, Ltd.), and 600 parts of cyclohexanone were charged and the mixture was heated to 85°C. Next, 4.50 parts of 1,8-diazabicyclo[5.4.0]-7-undecene (manufactured by Tokyo Chemical Industry Co., Ltd.) were added as a catalyst, and the mixture was stirred at 85°C for 8 hours. Then, 284.3 parts of glycidyl methacrylate (manufactured by Dow Chemical Japan, molecular weight 142, abbreviated as GMA) and 292.9 parts of cyclohexanone were added, and then 7.20 parts of dimethylbenzylamine (manufactured by Wako Pure Chemical Industries, Ltd.) were added as a catalyst, and the mixture was stirred at 85°C for 6 hours. The mixture was then cooled to 20°C to obtain a cyclohexanone solution of (meth)acrylate (a3-9) having six acryloyl groups and two methacryloyl groups, with a refractive index of 1.565 (nD25). This reaction solution was pale yellow and transparent, with a solid content of 60% and a manganese content of 1400.

[0072] <Manufacturing of other polymerizable compounds (a4)>

[0073] (Synthesis Example 17) A resin solution 16 containing 75% urethane acrylate 16 (a4-2) was obtained in the same manner as in Synthesis Example 1, except that the materials and proportions were changed as shown in Table 3. The obtained urethane acrylate 16 had a molecular weight of 2300.

[0074] <Silica particles (B)> (b-1): PGM-AC-2140Y (manufactured by Nissan Chemical Corporation, a propylene glycol monomethyl ether dispersion of silica particles having acryloyl groups on the surface of particles treated with 3-[(meth)acryloyloxy)propyl]trimethoxysilane, average particle size 12 nm, non-volatile content (percentage) 46.8%) (b-2): PGM-AC-4130Y (manufactured by Nissan Chemical Corporation, a propylene glycol monomethyl ether dispersion of silica particles having acryloyl groups on the surface of particles treated with 3-[(meth)acryloyloxy)propyl]trimethoxysilane, average particle size 45 nm, non-volatile content (percentage) 32.1%) (b-3): PGM-AC-5140Z (manufactured by Nissan Chemical Corporation, a methyl ethyl ketone dispersion of silica particles having acryloyl groups on the surface of particles treated with 3-[(meth)acryloyloxy)propyl]trimethoxysilane, average particle size 80 nm, non-volatile content (percentage) 40.5%)

[0075] <Silica particles other than silica particles (B)> (b'-1): MSD-57 (manufactured by Sakai Chemical Industry Co., Ltd., dispersion of silica particles having acryloyl groups on the particle surface, average particle size 200 nm, non-volatile content 55.0%) (b'-2): PGM-ST (manufactured by Nissan Chemical Corporation, an ethylene glycol dispersion of silica particles without acryloyl groups on the surface of untreated particles, average particle size 12 nm, non-volatile content 30.5%)

[0076] <Leveling agent> BYK-355 (manufactured by Bic Chemie, medium polarity, acrylic leveling agent, solvent: propylene glycol monomethyl ether acetate, solution of acrylic polymer, non-volatile content 52%)

[0077] <Photopolymerization initiator> DAIDO UV-CURE #174 (manufactured by Daido Chemical Industries, Ltd., 1-hydroxycyclohexylphenyl ketone, acetophenone-based photopolymerization initiator) ESACURE ONE (manufactured by IGM Resins, oligo(hydroxy-2-methyl-)propanone, acetophenone-based photopolymerization initiator)

[0078] (Example 1) In a flask equipped with a stirring device, add 50 parts of a resin solution containing urethane acrylate 1 (a1-1) (75% non-volatile content) on a non-volatile content basis, 50 parts of MIWON's MIRAMER HR6042 (EO-modified bisphenol full orange acrylate, abbreviated as BPFL(EO)DA, molecular weight 550, refractive index 1.600 (nD25)) (a3-1) (a3-1) (60% by mass) and a mixture of OPPEA (a3-2) (40% by mass), 170 parts of silica particles (b-1) (B) on a non-volatile content basis, 0.125 parts of BYK-355 (manufactured by Bic Chemie Japan) as a leveling agent (C), and 1.9 parts of Esacure One (manufactured by DKSH Japan Co., Ltd.) as a photopolymerization initiator, and DAIDO 4.8 parts of UV-CURE#174 (manufactured by Daido Chemical Industries, Ltd.) were thoroughly mixed, and propylene glycol monomethyl ether was added as an organic solvent to obtain a coating composition with a non-volatile content of 50%.

[0079] Manufacturing of substrates with a primer layer The coating compositions obtained in the examples and comparative examples were applied to 50 μm thick polyethylene terephthalate (PET) films (Toray Industries, Inc.'s "Lumirror U403") using a bar coater to achieve a dry film thickness of 5.0 μm, and then subjected to a high-pressure mercury lamp treatment at 500 mJ / cm². 2 A substrate with a primer layer was prepared by irradiating it with ultraviolet light.

[0080] (Examples 2) to (Examples 53), (Comparative Example 1) to (Comparative Example 8) Coating compositions with a non-volatile content of 50% were obtained in the same manner as in Example 1, except that the blending amounts (parts by mass, calculated as non-volatile content) shown in Tables 5 to 18 were changed. Furthermore, substrates having a primer layer were prepared in the same manner as in Example 1.

[0081] The evaluation methods and criteria are shown below. ≪Hayes≫ The haze value on the surface of the primer layer of the substrate having the primer layer prepared as described above was measured using a "Haze Meter SH7000" manufactured by Nippon Denshoku Industries Co., Ltd. A haze value of 1.0% or less is acceptable for practical use. [Evaluation Criteria] 3: Haze value less than 0.8%: Good 2: Haze value of 0.8-1%: No practical problems. 1: Haze value exceeds 1%: Not practical.

[0082] Exterior The substrates having the primer layer prepared as described above were visually inspected for any coating defects. [Evaluation Criteria] 2: No coating defects: No practical problems. 1: Coating defect present: Unusable

[0083] ≪Abrasion resistance≫ The abrasion resistance of the substrate with the prepared primer layer was evaluated using the "JSPS-type friction fastness tester" manufactured by Tester Sangyo Co., Ltd. A friction element with a load of 1000g attached (surface area 1cm²) was used. 2 Steel wool #0000 was attached to the ) and the surface of the primer layer (1cm x 15cm) was moved back and forth 10 times. After that, the number of scratches on the surface of the primer layer was counted and evaluated according to the following criteria. A smaller number of scratches is better, and if there are 3 or fewer scratches, it can be used without any practical problems. [Evaluation Criteria] 3: No scratches (0): Good condition 2: 1 to 3 scratches: No practical problems. 1: 4 or more scratches: Unusable

[0084] ≪Curving≫ The obtained optical components for evaluation were punched out using an SD-type lever-type sample cutter (SDL-100, manufactured by Dumbbell Co., Ltd.) with a 100mm (long side) x 50mm (short side) cutting die set in it, creating a test film of 100mm (long side) x 50mm (short side). This test film was left in a constant temperature and humidity chamber at 23°C and 50%RH for 6 hours. The test film was placed with the coated side down, with the long side in contact with the horizontal surface of the laboratory bench, and the distance between the two ends of the convexly curved short side was measured using a microgauge, and the average value was calculated. [Evaluation Criteria] 4:45mm or more: Very good 3: 35mm to less than 45mm: Good 2: 30mm to less than 35mm: No practical problems. 1: Cylindrical or less than 30mm: Not practical.

[0085] ≪Interference unevenness≫ The substrate with the prepared primer layer was cut into 5cm x 5cm pieces using the same method as the evaluation described above. The surface of the PET substrate opposite the coated surface was rubbed with sandpaper back and forth about 10 times to smooth the surface, and then black matte paint was dropped onto it and dried at 70°C for 2 minutes. The 5° absolute reflectance was measured using a spectrophotometer (Hitachi High-Technologies Corporation, model: U-4100), and the amplitude of the ripple (wave pattern) in the reflection curve was observed at wavelengths of 540~560nm. [Evaluation Criteria] 3: Ripple amplitude is 0.2% or less: Good 2: Ripple amplitude greater than 0.2% and less than or equal to 0.5%: No practical problems. 1: Ripple amplitude exceeding 0.5%: Not practical for use.

[0086] <Fabrication of laminates> On the primer layers of the substrates having the primer layers prepared in Examples 1 to 53 and Comparative Examples 1 to 8 described above, silicon oxide was sputtered to a thickness of 0.1 μm using a Magtron sputter MSP-30T manufactured by Vacuum Devices Co., Ltd. to form a silicon oxide film, and laminates were fabricated accordingly.

[0087] <<Initial adhesion>> The adhesion between the silicon oxide film and the primer layer was evaluated by making a grid pattern of 100 squares on the silicon oxide film of the fabricated laminate using a cutter at 1 mm intervals, then applying cellophane tape to cover the entire grid pattern, peeling it off, and visually observing the peeling state of the silicon oxide film. The adhesion was evaluated according to the following criteria. The less peeling there is, the better the adhesion; an evaluation of 3 or higher indicates that it can be used without practical problems. [Evaluation Criteria] 4: The area around the scratch line is perfectly smooth, and there is no peeling in any of the grid lines. : Very good 3: Small peeling of the silicon oxide film is observed around the intersections of the scratches, but the total area of ​​peeling is less than 5% of the grid pattern. : Good 2: The silicon oxide film peels off along the edge of the scratch, or at the intersection of the scratches, and the total area of ​​peeling is between 5% and 10% of the grid pattern. : No practical problems. 1: The total area of ​​peeled-off material exceeds 10% of the grid squares. : Unusable.

[0088] ≪Adhesion after boiling≫ The prepared laminate was boiled in pure water for 6 hours, then allowed to cool to 20°C, and an adhesion test was performed in the same manner as the "initial adhesion" test described above. The evaluation results are shown in Tables 5 to 17.

[0089] [Table 5]

[0090] [Table 6]

[0091] [Table 7]

[0092] [Table 8]

[0093] Table 9

[0094] Table 10

[0095] Table 11

[0096] Table 12

[0097] Table 13

[0098] Table 14

[0099] Table 15

[0100] Table 16

[0101] Table 17

[0102] Table 18

[0103] It has been confirmed that by using the coating composition of the present invention, a laminate can be obtained that exhibits excellent adhesion between the formed primer layer and the inorganic oxide layer, excellent surface scratch resistance, low haze, minimal warping, no interference unevenness, and minimal change in adhesion even after boiling tests.

Claims

1. A coating composition for forming a primer layer to be placed between a substrate and an inorganic oxide layer, The coating composition contains a polymerizable compound (A) and silica particles (B) having (meth)acryloyl groups with an average particle size of 2 to 150 nm. The polymerizable compound (A) comprises at least one of a trifunctional or more urethane (meth)acrylate (a1) and a trifunctional or more (meth)acrylate (a2), and a (meth)acrylate (a3) ​​with a refractive index of 1.50 or more. The content of the silica particles (B) is 130 to 350 parts by mass per 100 parts by mass of the polymerizable compound (A), A coating composition characterized in that the haze value of the substrate on which a primer layer with a thickness of 5 μm formed from the coating composition is laminated is 1% or less. However, the three- or more functional urethane (meth)acrylate (a1) and the three- or more functional (meth)acrylate (a2) exclude the (meth)acrylate (a3) ​​with a refractive index of 1.50 or higher, and the three- or more functional (meth)acrylate (a2) excludes the urethane (meth)acrylate (a1).

2. The coating composition according to claim 1, characterized in that the (meth)acrylate (a3) ​​having a refractive index of 1.50 or more has a fluorene skeleton.

3. The coating composition according to claim 1, characterized in that the content of the trifunctional or more urethane (meth)acrylate (a1) is 10 to 80% by mass of the polymerizable compound (A) in 100% by mass.

4. The coating composition according to claim 1, characterized in that the trifunctional or more urethane (meth)acrylate (a1) has an alicyclic structure.

5. A laminate comprising, at least, a substrate, a primer layer formed by the coating composition described in any one of claims 1 to 4, and an inorganic oxide layer, arranged in this order.

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