WO2019208483A1

WO2019208483A1 - Low refractive index member, transfer sheet, coating composition, and multilayer body using low refractive index member

Info

Publication number: WO2019208483A1
Application number: PCT/JP2019/016982
Authority: WO
Inventors: 淳司鷲尾; 圭太塚本; 修清家; 智洋小川; 洋幸森兼; 隆伸唯木; 芳成松田; 篠原　誠司
Original assignee: 大日本印刷株式会社
Priority date: 2018-04-23
Filing date: 2019-04-22
Publication date: 2019-10-31
Also published as: JP2021165765A

Abstract

The present invention provides a low refractive index member which suppresses cracks, while achieving good visibility by suppressing whitening in spite of thick film thickness of a low refractive index layer, and which is capable of maintaining anti-reflection properties. A low refractive index member which comprises a low refractive index layer on a base material, and which is configured such that: the low refractive index layer has a thickness of from 0.5 μm to 5.0 μm, while containing hollow particles and a binder resin; the hollow particles have an average particle diameter of from 60 nm to 140 nm; and a cured product of a composition that contains silicone compound is contained as the binder resin.

Description

Low refractive member, transfer sheet, coating composition, and laminate using low refractive member

The present invention relates to a low refractive member, a transfer sheet, a coating composition, and a laminate using the low refractive member.

A low-refractive member may be disposed on the surface of various articles such as an image display device such as a liquid crystal display device and a showcase in order to suppress reflection of external light.

The low refractive index member is provided with a layer having a low refractive index (low refractive index layer) on its surface, so that light reflected from the surface of the low refractive index layer is further reduced while lowering reflection at the surface of the low refractive index layer itself. And the light reflected by the surface of the lower layer of the low refractive index layer are designed to reduce the reflectance.
For this reason, the thickness of the low refractive index layer of the low refractive member is designed to be about 1/4 (around 100 nm) of the wavelength range of visible light (for example, Patent Document 1).

JP 2016-177186 A (paragraph 0045)

Since the low refractive index layer is a thin film of about 100 nm as in Patent Document 1, even when the low refractive index layer is slightly damaged by rubbing, the low refractive index layer partially disappears completely, and the antireflection effect is partially There is a problem of being lost. In particular, when hollow particles are used to lower the refractive index of the low refractive index layer, the scratch resistance of the low refractive index layer tends to be lowered, and thus the above problem tends to become remarkable.

In order to solve the above problem, there can be considered a means for forming the low refractive index layer by a dry process such as a sputtering method or a vacuum deposition method. However, the dry process requires a large amount of equipment, and there is a problem that the cost increases significantly.
In order to solve the above problem, a means for increasing the cross-linking density of the low refractive index layer by using an ionizing radiation curable resin composition as a binder resin for the low refractive index layer formed by a wet method may be considered. However, when the crosslink density of the low refractive index layer is increased using the ionizing radiation curable resin composition, curling may occur in the low refractive index member, and further, due to volume shrinkage of the low refractive index layer during crosslinking, The smoothness of the surface of the low refractive index layer is lost, and whitening due to surface diffusion may occur.

In order to solve the above problems, the present inventors set the thickness of the low refractive index layer in the wavelength range of visible light so that the antireflective property can be maintained even if the low refractive index layer is slightly scraped by abrasion. It was considered to make the thickness significantly larger than 1/4. However, when the thickness of the low refractive index layer is simply increased, haze is increased and the low refractive index layer is whitened to deteriorate visibility. There were frequent cases where cracks occurred in the refractive index layer.
Therefore, the present inventors have further studied diligently, and despite being thick in the low refractive index layer, whitening is suppressed, visibility is good, cracks are suppressed, and antireflection properties are maintained. This has led to the completion of a low refractive member that can be used.

The present invention provides the following [1] to [4].
[1] A low-refractive-index member having a low-refractive index layer on a substrate, the low-refractive index layer has a thickness of 0.5 to 5.0 μm, includes hollow particles and a binder resin, The hollow particles have an average particle diameter of 60 to 140 nm, and include a cured product of a composition containing a silicone compound as the binder resin.
[2] A transfer sheet having a transfer layer on a substrate, wherein the substrate side of the transfer layer is a low refractive index layer, and the low refractive index layer has a thickness of 0.5 to 5.0 μm. A transfer sheet comprising hollow particles and a binder resin, the hollow particles having an average particle diameter of 60 to 140 nm, and containing a cured product of a composition containing a silicone compound as the binder resin.
[3] A coating composition for forming a low refractive index layer, comprising hollow particles having an average particle diameter of 60 to 140 nm and a silicone compound as a binder resin component.
[4] A laminate comprising a deposited film on the low refractive index layer of the low refractive member according to [1].

According to the present invention, it is possible to provide a low-refractive member, a transfer sheet, and a coating composition that can suppress whitening and have good visibility and maintain antireflection properties despite the fact that the film thickness is large. it can. Moreover, according to this invention, the laminated body using this low refractive member can be provided.

[Low refractive member]
The low refractive index member of the present invention has a low refractive index layer on a substrate, and the low refractive index layer has a thickness of 0.5 to 5.0 μm and contains hollow particles and a binder resin. The hollow particles have an average particle diameter of 60 to 140 nm and contain a cured product of a composition containing a silicone compound as the binder resin.

<Base material>
A base material becomes a support body at the time of forming a low refractive index layer.
The base material is preferably light transmissive, and specifically, the total light transmittance according to JIS K7361-1: 1997 is preferably 50% or more, more preferably 80% or more. Preferably, it is 90% or more.

Examples of the substrate include plastic and glass.
Glass is preferable because it is harder than plastic and easily improves the scratch resistance of the low refractive index layer.

Plastic base materials include polyolefin resins such as polyethylene and polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, vinyl resins such as ethylene / vinyl acetate copolymer, ethylene / vinyl alcohol copolymer, polyethylene terephthalate, polyethylene Polyester resins such as naphthalate and polybutylene terephthalate, acrylic resins such as poly (meth) methyl acrylate and poly (meth) ethyl acrylate, styrene resins such as polystyrene, and polyamide resins such as nylon 6 or nylon 66 , A cellulose resin such as triacetyl cellulose, a resin such as polycarbonate, or a polyimide resin.
Examples of the glass include alkali-free glass, nitride glass, soda-lime glass, borosilicate glass, and lead glass.

The thickness of the substrate is not particularly limited, but in the case of a plastic substrate, it is preferably 10 to 500 μm, more preferably 20 to 400 μm, and even more preferably 50 to 300 μm from the viewpoint of handleability. . The plastic substrate may be a plate having a thickness exceeding 500 μm.
In the case of glass, it is preferably 0.03 to 5.0 mm, more preferably 0.1 to 3.0 mm, from the viewpoint of handleability, strength, and weight reduction, and 0.3 to 2. More preferably, it is 0 mm.

The base material is not limited to a flat plate shape, and may be a three-dimensional shape having a curved surface. Further, the substrate is not limited to colorless, and may be colored.

<Low refractive index layer>
The low refractive index layer is formed on at least one surface of the substrate. Moreover, it is preferable that a low refractive index layer is located in the outermost surface on the opposite side to the base material of a low refractive member.

The low refractive index member of the present invention requires that the low refractive index layer has a thickness of 0.5 to 5.0 μm. When the thickness of the low refractive index layer is less than 0.5 μm, even if the low refractive index layer is slightly damaged by rubbing, the antireflective property of the rubbing portion disappears and visibility cannot be improved. Further, when the thickness of the low refractive index layer exceeds 5.0 μm, the absolute amount of the hollow particles increases, so that the low refractive index layer is whitened by internal diffusion, and the visibility cannot be improved. In the process of forming the low refractive index layer (curing shrinkage) and handling of the low refractive index member, cracks occur in the low refractive index layer.

Furthermore, the low refractive index member of the present invention requires that the low refractive index layer contains hollow particles and a binder resin, and the hollow particles have an average particle diameter of 60 to 140 nm.
When the average particle diameter of the hollow particles is less than 60 nm, the ratio of air having a low refractive index is decreased, so that the refractive index of the low refractive index layer cannot be sufficiently lowered, and the antireflection property is lowered. Moreover, when the average particle diameter of a hollow particle exceeds 140 nm, the spreading | diffusion of a hollow particle becomes strong, a low refractive index layer whitens and visibility cannot be made favorable.

Furthermore, the low refractive member of this invention needs to contain the hardened | cured material of the composition containing a silicone type compound as binder resin of a low refractive index layer.
When the cured product of the composition containing a silicone compound is not included as the binder resin, the refractive index of the low refractive index layer cannot be sufficiently lowered, and the antireflection property is lowered.

As described above, the low refractive member of the present invention has a low refractive index layer thickness of 0.5 to 5.0 μm, an average particle diameter of hollow particles of 60 to 140 nm, and a silicone compound as a binder resin. By including the hardened | cured material of the composition to contain, although the film thickness is thick, whitening is suppressed, visibility is favorable and it is possible to maintain antireflection property.

<< Hollow particles >>
A hollow particle refers to a particle having an outer shell layer, the inside of the particle surrounded by the outer shell layer being a cavity, and containing air inside the particle.
The outer shell layer of the hollow particles may be an inorganic substance or an organic substance, and examples thereof include those made of metal, metal oxide, resin, silica and the like. Among these, hollow silica particles whose outer shell layer is silica are preferable. By using hollow silica particles as the hollow particles, the affinity between the binder resin containing the cured product of the composition containing the silicone compound and the outer shell of the hollow particles is increased, and the difference in refractive index is reduced. The internal haze can be easily lowered.
When the outer shell layer is silica, the silica may be in a crystalline state, a sol state, or a gel state.
The shape of the hollow particles may be any of a spherical shape, a chain shape, a needle shape, a plate shape, a piece shape, a rod shape, a fiber shape, etc., such as a spherical shape, a spheroid shape, and a polyhedral shape that can approximate a sphere. Among these, a true spherical shape and a substantially spherical shape are preferable, and a spheroid shape or a true spherical shape is more preferable.

As described above, the hollow particles are required to have an average particle diameter of 60 to 140 nm. The average particle diameter of the hollow particles is preferably 65 to 130 nm, more preferably 67 to 120 nm, further preferably 70 to 110 nm, and still more preferably 70 to 100 nm.

The average particle diameter of the hollow particles of the low refractive index layer of the low refractive index member can be calculated by the following operations (1) to (4).
(1) In order to observe the particles of the low refractive index layer of the low refractive index member with a transmission electron microscope (TEM), the low refractive index member layer is sliced with FIB (focused ion beam). The thickness of the flakes is preferably in the range of 100 nm to 200 nm.
<Example of (1)>
The low refractive index member is extracted as a thin piece of about 100 nm thickness by FIB horizontally with the film.

(2) The thin piece of the low refractive index member layer of the low refractive member is imaged with a transmission electron microscope (TEM). The accelerating voltage of a transmission electron microscope (TEM) is preferably 100 kv to 200 kV, and the F.O.V (Field Of View) is preferably 365 nm square to 1825 nm square.
<Example of (2)>
Equipment used: JEOL transmission electron microscope ARM200F
Accelerating voltage: 200kV
Observation mode: HAADF-STEM
Observation magnification: × 500k
F.O.V (Field Of View): 365 nm square

(3) Image analysis is performed from the observed image according to the following procedure.
1. Arbitrary 10 particles are extracted from the observation image, and the particle portion is filled with image analysis software (paint or the like) along the outer diameter of the particle. When the particles are aggregated, the above-described painting operation is performed by dividing the aggregated particles into individual particles instead of considering the aggregated particles as one particle.
2. The area (px ^ 2) of the filled portion is calculated by image analysis software (ImageJ or the like).
3. The equivalent circle diameter (px) is calculated from the area.
4). The length per pixel is calculated from the scale bar of the TEM image.
5. Using the coefficient “4.”, the equivalent circle diameter (px) calculated in “3.” is converted to nm.
6. An average value of 10 equivalent circle diameters is obtained, and the obtained value is defined as “average particle diameter before correction (d)”.

(4) The value obtained by multiplying “d” obtained in (3) above by “1.25” is defined as the average particle diameter (D).
Average particle diameter (D) = 1.25 × d

In addition, “1.25” in the above (4) means that “the cross section of the particle observed in the above (1) to (3) is mostly shifted from the center of the particle” and “(1) above”. Based on “the average particle diameter (d) before correction is about 80% of the nominal value of the particle manufacturing company” obtained in (3).

The hollow particles are preferably surface-treated.
As the surface treatment of the hollow particles, a surface treatment using a silane coupling agent is more preferable, and among these, a surface treatment using a silane coupling agent having a (meth) acryloyl group or an epoxy group is preferably performed.
By subjecting the hollow particles to a surface treatment with a silane coupling agent, the affinity between the hollow particles and the binder resin is improved, the dispersion of the hollow particles becomes uniform, and aggregation of the hollow particles is less likely to occur. It is possible to easily suppress a decrease in transparency. In addition, since the general-purpose low-refractive index layer having a thickness of about 100 nm is thin, the aggregated hollow particles are not easily taken into the low-refractive index layer. On the other hand, in the low refractive index member of the present invention, since the low refractive index layer is thick, aggregated hollow particles are also taken into the low refractive index layer. For this reason, suppressing the aggregation of the hollow particles in the low refractive member of the present invention is more technically significant than a general-purpose low refractive index layer. In order to suppress the aggregation of the hollow particles, it is more preferable that the hollow particles satisfy the condition of the zeta potential described later.

Silane coupling agents include 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltri Methoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3 -Glycidoxypropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyl Limethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, tris- (trimethoxysilyl) Propyl) isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldi Ethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyl Silane, decyl trimethoxy silane, 1,6-bis (trimethoxysilyl) hexane, trifluoropropyl trimethoxy silane and vinyl trimethoxy silane and vinyl triethoxy silane and the like.

The content of the hollow particles is preferably 100 to 300 parts by mass, more preferably 150 to 250 parts by mass, and further preferably 180 to 220 parts by mass with respect to 100 parts by mass of the binder resin.
By setting the content of the hollow particles to 100 parts by mass or more, the refractive index of the low refractive index layer can be sufficiently lowered and the antireflection property can be easily improved. Further, by setting the content of the hollow particles to 300 parts by mass or less, while maintaining the scratch resistance, it is possible to suppress whitening of the low refractive index layer due to an increase in internal diffusion and to easily suppress a decrease in visibility. it can.

<< Binder resin >>
As described above, the low refractive member of the present invention needs to contain a cured product of a composition containing a silicone compound as a binder resin for the low refractive index layer. A silicone compound is a compound having a siloxane bond (Si—O—Si) in the molecule.
The binder resin may contain a resin other than the cured product of the composition containing the silicone compound, but the ratio of the cured product of the composition containing the silicone compound to the total amount of the binder resin is 50% by mass or more. Is preferably 70% by mass or more, more preferably 90% by mass or more, and still more preferably 100% by mass.
The silicone compound can be cured by, for example, a crosslinking reaction of a reactive functional group described later, a dealcohol condensation reaction of an alkoxy group, a dehydration condensation of a silanol group, or the like.

The silicone compound is preferably one in which a substituted hydrocarbon group having a reactive functional group as a substituent is directly connected to a silicon atom. Examples of the reactive functional group include an epoxy group, a mercapto group, a (meth) acryloyl group, an amino group, a vinyl group, and an isocyanate group.
Hereinafter, a silicone compound in which a substituted hydrocarbon group having a reactive functional group as a substituent is directly bonded to a silicon atom may be referred to as a “reactive functional group-containing silicone compound”.

When hollow particles are surface-treated with a silane coupling agent, the internal haze is reduced by using a reactive functional group-containing silicone compound, and whitening is suppressed even though the low refractive index layer is thick. Thus, the visibility can be easily improved. The reason for this is that by using a reactive functional group-containing silicone compound, the reactive functional group side of the silicone compound (the organic component-rich side) is the reactive functional group of the silane coupling agent attached to the hollow particles. This is considered to be because the difference in refractive index is reduced by being easily directed to the base.
The reactive group of the reactive functional group-containing silicone compound is a cationic reactive reactive group with small polymerization shrinkage from the viewpoint of suppressing interfacial peeling between the hollow particles and the binder resin and suppressing surface irregularities of the low refractive index layer. It is preferable that it is an epoxy group excellent in adhesiveness with glass or silica. Suppressing the surface unevenness of the low refractive index layer leads to suppression of whitening of the low refractive index layer and improvement of scratch resistance of the low refractive index layer, and a uniform deposition film is formed on the low refractive index layer. It is preferable in that it can be easily made.

The reactive functional group-containing silicone compound preferably has a reactive functional group equivalent of 200 to 900 g / mol, more preferably 220 to 600 g / mol, and still more preferably 250 to 400 g / mol.
By setting the reactive functional group equivalent to 900 g / mol or less, the amount of the reactive functional group becomes sufficient, and the above effect (good visibility) can be easily obtained. In addition, by setting the reactive functional group equivalent to 200 g / mol or more, the shrinkage due to the self-crosslinking of the reactive functional group is suppressed, and the interfacial peeling between the hollow particles and the binder resin and the uneven surface of the low refractive index layer are made. Can be easily suppressed.

The reactive functional group-containing silicone compound includes one or more hydrolysates of an organosilicon compound represented by the following general formula (1) and one or more hydrolysates of an organosilicon compound represented by the following general formula (1). Decomposed polycondensates, hydrolyzed polycondensates of one or more organosilicon compounds represented by the following general formula (1) and one or more organosilicon compounds represented by the following general formula (2) It is done. Among these, at least one hydrolyzed polycondensate of an organosilicon compound represented by the following general formula (1) and at least one organosilicon compound represented by the following general formula (1) and the following general formula ( The hydrolyzed polycondensate with one or more of the organosilicon compounds represented by 2) is preferable because it is difficult to volatilize even with heat during the formation of the vapor deposition film, and thus it is easy to improve the adhesion with the vapor deposition film. Hereinafter, in the present specification, one or more hydrolyzed polycondensates of an organosilicon compound may be referred to as an “oligomer-type silicone compound”.

R _n —SiX _4-n (1)
[In the formula (1), n is an integer of 1 to 3. In the formula (1), R is a substituted hydrocarbon group having 1 to 10 carbon atoms having a reactive functional group as a substituent. When n is 2 to 3, R is the same or different from each other. May be. In the formula (1), X is an alkoxy group having 1 to 4 carbon atoms, silanol group, halogen or hydrogen, and when n is 1 to 2, X may be the same or different from each other. ]
R ² _n -SiX _4-n (2)
[In the formula (2), n is an integer of 1 to 3. In the formula (2), R ² is an unsubstituted or substituted hydrocarbon group having 1 to 10 carbon atoms having no reactive functional group. When n is 2 to 3, R ² is the same as each other. Or different. In the formula (2), X is an alkoxy group having 1 to 4 carbon atoms, silanol group, halogen or hydrogen, and when n is 1 or 2, X may be the same or different from each other. ]

Examples of the organosilicon compound represented by the general formula (1) include β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxymethyltrimethoxysilane, and γ-glycidoxymethyltriexisilane. Γ-glycidoxyethyltrimethoxysilane, γ-glycidoxyethyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane , Γ-glycidoxypropyltriethoxysilane, γ- (β-glycidoxyethoxy) propyltrimethoxysilane, γ- (meth) acrylooxymethyltrimethoxysilane, γ- (meth) acrylooxymethyltrioxy Silane, γ- (meth) acrylooxyethyltrimethoxysilane, γ- (Meth) acrylooxyethyltriethoxysilane, γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ -(Meth) acryloxypropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, etc. Is mentioned.
Examples of the organosilicon compound represented by the general formula (2) include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, and diphenyldimethoxysilane. , Methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltrimethoxysilane, butyltrimethoxysilane, isobutyltriethoxysilane, hexyltriethoxysilaoctyltriethoxysilane, decyltriethoxysilane, Butyltriethoxysilane, isobutyltriethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, decyltriethoxysilane, 3, , 3-trifluoropropyl trimethoxy silane, methyl-3,3,3-trifluoropropyl dimethoxysilane, perfluorooctyl ethyl trimethoxysilane and perfluorooctyl triethoxysilane and the like.

Further, as the silicone compound, one or more hydrolyzed polycondensates of the organosilicon compound represented by the general formula (2) are also preferable. One or more hydrolyzed polycondensates of the organosilicon compound represented by the general formula (2) can suppress unevenness of the surface of the low refractive index layer due to curing shrinkage, and further, when forming a deposited film Since it is difficult to volatilize even with heat, it is preferable in terms of easy adhesion to the deposited film.

The silicone compound preferably has an alkoxy group. In addition, the alkoxy group is preferably directly bonded to a silicon atom.
By using a silicone-based compound having an alkoxy group, when the substrate is glass, the adhesion between the substrate and the low refractive index layer can be improved, and the scratch resistance can be further improved. . In addition, by using a silicone-based compound having an alkoxy group, the adhesion of the low refractive index layer and the vapor deposition film is good when the structure of the laminate described later (the composition having the vapor deposition film on the low refractive index layer) is used. Can be.

The amount of the alkoxy group in the silicone compound having an alkoxy group is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, and further preferably 15 to 45% by mass.
By setting the amount of the alkoxy group to 5% by mass or more, it is possible to easily improve the adhesion with an inorganic substance (for example, glass as a base material, or a deposited film formed on a low refractive index layer), By controlling the amount of the alkoxy group to 60% by mass or less, the shrinkage of the low refractive index layer due to the dealcoholization reaction of the alkoxy group is suppressed. Can be easily suppressed.

The composition containing a silicone compound may contain a curing catalyst as necessary.
For example, when the reactive functional group of the reactive functional group-containing silicone compound is an epoxy group, the composition containing the silicone compound includes at least one selected from an amine catalyst, an acidic catalyst, and a basic catalyst as a curing catalyst. It is preferable to contain.
Moreover, in order to accelerate | stimulate reaction with the alkoxy group of a silicone compound type compound, and inorganic substances, such as glass, the composition containing a silicone type compound is 1 or more types of catalysts chosen from an acidic catalyst, a basic catalyst, and an amine catalyst It is preferable to contain.

<< Thickness >>
As described above, the low refractive index member of the present invention requires that the low refractive index layer has a thickness of 0.5 to 5.0 μm.
The thickness of the low refractive index layer is preferably 0.7 to 4.0 μm, more preferably 0.8 to 3.5 μm, and further preferably 1.0 to 3.0 μm.
In the present specification, the thickness of the low refractive index layer can be calculated as an average value of 10 measured values. The thickness variation is preferably within ± 15% of the average thickness, more preferably within ± 10%, further preferably within ± 7%, and more preferably within ± 5%. It is even more preferable.
The thickness of the low refractive index layer can be measured by, for example, a microspectrophotometer.

<< refractive index >>
The refractive index of the low refractive index layer is preferably 1.30 or less, and more preferably 1.27 or less. By setting the refractive index of the low refractive index layer to 1.30 or less, it is possible to suppress an increase in the reflectance of the surface of the low refractive index layer and to improve the visibility. The lower limit of the refractive index of the low refractive index layer is about 1.10.
In this specification, the refractive index refers to a refractive index at a wavelength of 589.3 nm.
The refractive index of the low refractive index layer can be calculated, for example, with a microspectrophotometer.

The low refractive index layer may contain additives such as an antistatic agent, an antioxidant, a surfactant, a dispersant, and an ultraviolet absorber.

For example, the low refractive index layer is formed by applying a low refractive index layer-forming coating composition containing each component constituting the low refractive index layer on the substrate, drying, and curing the wet method, and a wet method on the substrate. It can be formed by a transfer method or the like that transfers the low refractive index layer.

<Other layers>
The low refractive member of the present invention may have other layers between the base material and the low refractive index layer.
Examples of other layers include a hard coat layer for improving the scratch resistance of the low refractive index layer, an adhesive layer for improving the adhesion between the substrate and the low refractive index layer, and an antistatic layer. Can be mentioned.

<Optical characteristics>
Low refractive member of the present invention is preferably diffuse light reflectance R _SCE measured from the low refractive index layer side is in the range below.
The _RSCE measures the reflected light other than the reflected light passing through the light trap, which is measured by applying light from all directions to the sample surface using an integrating sphere and opening the light trap corresponding to the regular reflection direction. It is the reflectance calculated from the measured value. The surface of the low refractive index layer is almost smooth, and the ratio of diffusely reflected light is smaller than that of regular reflected light. For this reason, _{RSCE obtained} by removing regular reflection light from total reflection light represents diffuse reflection light that is a very small component, and is a parameter suitable for indicating the amount of diffuse reflection inside the low refractive index layer. I can say that.
Measuring device of a typical _{R SCE} is, JIS Z8722: has a configuration conforming to the geometric-condition c 2009. More specifically, a typical _RSCE measuring apparatus uses D65 as the light source of the integrating sphere spectrophotometer, the position of the light receiver is +8 degrees with respect to the normal of the sample, and the position of the light trap is It is −8 degrees with respect to the normal of the sample, and the viewing angle is 2 degrees or 10 degrees. As a measurement apparatus of R _SCE include the trade name CM-2600d manufactured by Konica Minolta Co., Ltd.. In this specification, the viewing angle is 2 degrees.

The diffuse light reflectivity _RSCE is preferably 1.5% or less, more preferably 1.0% or less, and further preferably 0.5% or less.
By setting _RSCE to 1.5% or less, the amount of diffuse reflection inside the low refractive index layer is reduced, and whitening can be suppressed. _The lower limit of _{R SCE} is about 0.01%.

In addition, when the low refractive member has light transmittance as a whole, in order to eliminate the influence of the back reflection of the low refractive member, the surface of the low refractive member opposite to the surface having the low refractive index layer is black. create a sample obtained by laminating Chakuzaiso and back films, it is preferable to measure the R _SCE a low refractive index layer side of the sample. The same applies to the measurement of luminous reflectance Y value described later.
The sample black adhesive layer preferably has a total light transmittance of 1% or less. Further, the difference (Δn) between the refractive index of the surface of the low refractive member opposite to the surface having the low refractive index layer (for example, the refractive index of the substrate) and the refractive index of the binder resin of the black adhesive layer Is preferably within 0.10.

In this specification, R _SCE , haze, total light transmittance, and luminous reflectance Y value are average values of measured values at 10 locations.

The low refractive member of the present invention preferably has a haze according to JIS K7136: 2000 of 1.0% or less, more preferably 0.5% or less, and further preferably 0.2% or less. preferable. By setting the haze to 1.0% or less, whitening of the low refractive index layer can be suppressed and visibility can be easily improved.

The low refractive member of the present invention preferably has a total light transmittance of JIS K7361-1: 1997 of 50.0% or more, more preferably 80% or more, and even more preferably 90% or more. .

In the low refractive member of the present invention, the luminous reflectance Y value measured at a light incident angle of 5 degrees from the side having the low refractive index layer is preferably 3.0% or less, and is 2.0% or less. Is more preferable. In this specification, the luminous reflectance Y value refers to the luminous reflectance Y value of the CIE 1931 standard color system. The luminous reflectance Y value can be calculated using a spectrophotometer (for example, trade name “UV-3600 plus” manufactured by Shimadzu Corporation).

<Size, shape, etc.>
The low refractive member may be in the form of a single sheet cut into a predetermined size, or may be in the form of a roll obtained by winding a long sheet into a roll. The size of the sheet is not particularly limited, but the maximum diameter is about 2 to 500 inches. The “maximum diameter” refers to the maximum length when any two points of the low refractive member are connected. For example, when the low refractive member is rectangular, the diagonal of the region is the maximum diameter. When the low refractive member is circular, the diameter is the maximum diameter.
The width and length of the roll are not particularly limited, but generally the width is about 500 to 3000 mm and the length is about 500 to 5000 m. The roll-shaped low-refractive member can be used by cutting into a single sheet according to the size of the image display device or the like. When cutting, it is preferable to exclude a roll end portion whose physical properties are not stable.
Further, the shape of the single wafer is not particularly limited, and may be, for example, a polygon (triangle, quadrangle, pentagon, etc.), a circle, or a random irregular shape.

[Transfer sheet]
The transfer sheet of the present invention has a transfer layer on a substrate, the substrate side of the transfer layer is a low refractive index layer, and the low refractive index layer has a thickness of 0.5 to 5. The hollow particles have an average particle diameter of 60 to 140 nm, and the binder resin contains a cured product of a composition containing a silicone compound as the binder resin. It is a waste.

<Base material>
The base material of the transfer sheet is preferably a plastic film from the viewpoint of workability during transfer sheet production and transfer.
As the plastic film as the substrate of the transfer sheet, the same plastic film as exemplified as the substrate of the low refractive member can be used. The thickness of the plastic film is preferably 10 to 500 μm, more preferably 20 to 400 μm, and even more preferably 50 to 300 μm from the viewpoint of handleability.
The substrate surface of the transfer sheet may be subjected to a release treatment in order to make it easy to peel the transfer layer from the substrate.

Ra, Rz, and Rp are preferably in the following ranges on the surface of the substrate on which the low refractive index layer is formed in order to suppress surface irregularities of the low refractive index layer exposed on the surface of the transfer layer after transfer. Details of Ra, Rz and Rp (measurement method and the like) will be described later.
Ra: 2.5 nm or less Rz: 25 nm or less Rp: 12 nm or less

Ra is more preferably 2.0 nm or less, further preferably 1.5 nm or less, and still more preferably 1.2 nm or less. The lower limit of Ra is about 0.3 nm.
Rz is more preferably 20 nm or less, further preferably 15 nm or less, and still more preferably 10 nm or less. The lower limit of Rz is about 3 nm.
Rp is more preferably 10 nm or less, further preferably 8 nm or less, and further preferably 6 m or less. The lower limit of Rp is about 2 nm.

<Transfer layer>
The transfer layer has at least a low refractive index layer. Further, the substrate side of the transfer layer is composed of a low refractive index layer.
The low refractive index layer constituting the transfer layer has a thickness of 0.5 to 5.0 μm and contains hollow particles and a binder resin, and the hollow particles have an average particle diameter of 60 to 140 nm. As a cured product of a composition containing a silicone compound.
Embodiments and preferred embodiments of the low refractive index layer constituting the transfer layer, the hollow particles contained in the low refractive index layer and the binder resin, and the preferred embodiments are the low refractive index layer and the low refractive index of the low refractive member of the present invention described above. This is the same as the embodiment and preferred embodiment of the hollow particles and binder resin contained in the rate layer. However, the surface shape of the low refractive index layer of the low refractive index member of the present invention described above (the surface shape opposite to the substrate of the low refractive index layer) is the base of the low refractive index layer in the transfer sheet of the present invention. This corresponds to the shape of the surface on the material side (the shape of the surface exposed after transfer).

The transfer layer may have other layers on the side opposite to the substrate with the low refractive index layer as a reference. Examples of other layers include a hard coat layer for improving the scratch resistance of the low refractive index layer, an adhesive layer for improving the adhesion between the adherend and the transfer layer, and an antistatic layer. It is done. In particular, in order to improve the adhesion to the adherend, the transfer layer preferably has an adhesive layer on the surface opposite to the substrate.
The transfer layer can have a laminated structure such as the following (1) to (3). In the case of the following (3), a resin having adhesiveness may be included as a binder resin for the low refractive index layer. In the following (1) to (3), it means that the layer located on the left side is closer to the substrate, and “/” means the interface of the layers.
(1) Low refractive index layer / adhesive layer (2) Low refractive index layer / hard coat layer / adhesive layer (3) Low refractive index layer

For the adhesive layer of the transfer layer, it is preferable to use a heat-sensitive or pressure-sensitive resin suitable for the material of the adherend. For example, when the material of the adherend is an acrylic resin, it is preferable to use an acrylic resin. If the material of the adherend is polyphenylene oxide / polystyrene resin, polycarbonate resin, or styrene resin, use an acrylic resin, polystyrene resin, polyamide resin, or the like that is compatible with these resins. Is preferred. Further, when the material of the adherend is a polypropylene resin, it is preferable to use a chlorinated polyolefin resin, a chlorinated ethylene-vinyl acetate copolymer resin, a cyclized rubber, or a coumarone indene resin. Further, when the material of the adherend is glass, it is preferable to use an ethylene-vinyl acetate copolymer resin and a polyethylene resin. Moreover, when the material of the adherend is glass, adhesion with various adhesives can be improved by using glass surface-treated with a silane coupling agent.
The adhesive layer may be a so-called transparent optical adhesive layer (OCA). The transparent optical adhesive layer is made of an acrylic resin from the viewpoints of optical properties, light resistance, weather resistance, heat resistance, and transparency.
The thickness of the adhesive layer is preferably 0.1 to 50 μm, and more preferably 0.5 to 30 μm.

The hard coat layer of the transfer layer preferably contains a cured product of a curable resin composition such as a thermosetting resin composition or an ionizing radiation curable resin composition, and from the viewpoint of improving scratch resistance, ionizing radiation. More preferably, it contains a cured product of the curable resin composition.

The thermosetting resin composition is a composition containing at least a thermosetting resin, and is a resin composition that is cured by heating. Examples of the thermosetting resin include acrylic resin, urethane resin, phenol resin, urea melamine resin, epoxy resin, unsaturated polyester resin, and silicone resin. In the thermosetting resin composition, a curing agent is added to these curable resins as necessary.

The ionizing radiation curable resin composition is a composition containing a compound having an ionizing radiation curable functional group (hereinafter also referred to as “ionizing radiation curable compound”). Examples of the ionizing radiation curable functional group include an ethylenically unsaturated bond group such as a (meth) acryloyl group, a vinyl group, and an allyl group, an epoxy group, and an oxetanyl group. As the ionizing radiation curable compound, a compound having an ethylenically unsaturated bond group is preferable, a compound having two or more ethylenic unsaturated bond groups is more preferable, and among them, having two or more ethylenically unsaturated bond groups, Polyfunctional (meth) acrylate compounds are more preferred. As the polyfunctional (meth) acrylate compound, any of a monomer and an oligomer can be used.
The ionizing radiation means an electromagnetic wave or a charged particle beam having an energy quantum capable of polymerizing or cross-linking molecules, and usually ultraviolet (UV) or electron beam (EB) is used. Electromagnetic waves such as X-rays and γ-rays, and charged particle beams such as α-rays and ion beams can also be used.
In this specification, (meth) acrylate means acrylate or methacrylate, (meth) acrylic acid means acrylic acid or methacrylic acid, and (meth) acryloyl group means acryloyl group or methacryloyl group. means.

The thickness of the hard coat layer is preferably 0.1 to 100 μm, more preferably 0.5 to 50 μm, and further preferably 1 to 30 μm. By setting the thickness of the hard coat layer in the above range, it is possible to easily suppress the occurrence of cracks in the transfer layer during transfer while improving the scratch resistance. When high hardness is required as in the case of glass replacement, the thickness of the hard coat layer is preferably 10 to 30 μm.

In order to improve the peelability of the transfer layer, a release layer may be provided between the substrate and the transfer layer. The release layer can be formed from a general-purpose release agent such as a silicone release agent or a fluorine release agent.

<<< Surface shape of substrate side of low refractive index layer constituting transfer layer >>>
As described above, the substrate side of the transfer layer is composed of a low refractive index layer. The surface shape on the base material side of the low refractive index layer (surface shape on the side opposite to the base material of the low refractive index layer) is the arithmetic average roughness Ra, the maximum height Rz, and the maximum height Rp of the roughness curve. It is preferable that one or more selected from the following range is satisfied, two or more satisfy the following range, and it is more preferable that all three satisfy the following range.
A low refractive index layer is located on the surface of the laminate obtained by transferring the transfer layer onto the adherend. Therefore, when Ra, Rz, and Rp satisfy the following ranges, when the surface of the laminate (the surface of the low refractive index layer) is rubbed with a nail or the like, the nail or the like may be scratched by unevenness, thereby causing scratches. It can be suppressed and the scratch resistance can be easily improved. Moreover, when Ra, Rz, and Rp satisfy the following ranges, when the surface of the laminate (the surface of the low refractive index layer) is touched with a finger or the like, the refractive index changes due to sebum entering the irregularities. And it can suppress that anti-reflective property falls.
Ra: 2.5 nm or less Rz: 25 nm or less Rp: 12 nm or less

Ra is more preferably 2.0 nm or less, further preferably 1.5 nm or less, and still more preferably 1.2 nm or less. In addition, Ra is preferably 0.3 nm or more in order to suppress the recognition of very small scratches.
Rz is more preferably 20 nm or less, further preferably 15 nm or less, and still more preferably 10 nm or less. In addition, Rz is preferably 3 nm or more in order to suppress the observation of very small scratches.
Rp is more preferably 10 nm or less, further preferably 8 nm or less, and further preferably 6 m or less. Note that Rp is preferably 2 nm or more in order to suppress the observation of very small scratches.

Ra, Rz, and Rp shall be defined in accordance with JIS B0601: 2001. Ra, Rz, and Rp are calculated as follows using an atomic force microscope (trade name “WET-9100”, manufactured by Shimadzu Corporation). Specifically, first, a plurality of flat circular metal plates are prepared, and a carbon double-sided tape manufactured by Nissin EM Co., Ltd. is attached to each metal plate, and the metal plate and the deposition are attached via the tape. A measurement sample in which a laminate formed by transferring a transfer layer onto a body is bonded to the adherend side is prepared. Then, in order to ensure the adhesion of the metal plate, the tape and the laminate, the measurement sample is left overnight in a desiccator. After standing overnight, the sample for measurement is fixed with a magnet on the measurement table of an atomic force microscope (trade name “WET-9400”, manufactured by Shimadzu Corporation), and the measurement area is 5 μm square in the tapping mode. Observe the surface shape with a force microscope. Then, Ra, Rz, and Rp are calculated from the observed data using surface analysis software built in the atomic force microscope. Note that the vertical scale during the surface analysis is 20 nm. The observation atmosphere is 23 ° C. ± 5 ° C. and a humidity of 40 to 65%, and NCHR-20 manufactured by NanoWorld is used as the cantilever. For observation, 10 locations are selected at random from locations free from foreign matter or scratches for one sample, and the surface shapes at 10 locations are observed. Then, Ra, Rz, Rp are calculated using the surface analysis software built in the atomic force microscope, and the arithmetic average values of the 10 points are calculated as Ra, Rz, Rp for each sample. And

The reason why the surface shape of the low refractive index layer on the substrate side is defined using Ra, Rz, and Rp is as follows.
Ra is used to see the average value of the heights of the peaks and valleys existing on the surface of the low refractive index layer, and Rz is the maximum value of the peak height and the valley depth of the surface of the low refractive index layer. It is used to see the sum of the maximum values, and Rp is used to see the maximum value of the peak height of the surface of the low refractive index layer. Here, since Ra is looking at the average value of the heights of the peaks and valleys present on the surface of the low refractive index layer, although the surface shape of the rough low refractive index layer can be understood, there are large peaks and valleys. May be averaged out and overlook their existence. In addition, since Rp looks at the maximum peak height of the surface of the low refractive index layer, when two parameters Ra and Rp are used, even if there is a large valley, the existence is overlooked. Furthermore, since Rz looks at the sum of the maximum peak height and the maximum valley depth of the surface of the low refractive index layer, when two parameters Ra and Rz are used, It may not be possible to know whether the mountain is high or the valley is deep. Therefore, in order to more accurately determine whether or not the surface has a uniform and flat surface shape, one parameter of Ra, two parameters of Ra and Rp, or two parameters of Ra and Rz are not sufficient. , Rz and Rp are required. For this reason, in the present invention, the surface shape of the low refractive index layer is defined using three parameters Ra, Rz and Rp.

In order to make Ra, Rz, and Rp within the above ranges, it is preferable that the surface of the low refractive index layer on the base material side has a region where substantially no hollow particles are present. In other words, it is preferable that the surface of the low refractive index layer on the substrate side has a region where only the binder resin is substantially present.
Since the specific gravity of hollow particles is light, the hollow particles emerge on the surface of the coating film by applying a coating composition containing hollow particles and a binder resin component on the substrate of the transfer sheet to form a low refractive index layer. Moreover, it is possible to easily form a region where the hollow particles are sparse and the binder resin is dense on the surface of the low refractive index layer on the substrate side.
By having a region where only the binder resin is present on the surface of the base material side of the low refractive index layer, the surface unevenness of the laminate formed by transferring the transfer layer onto the adherend is reduced, and scratch resistance In addition, it is possible to improve the anti-fouling property since the dirt can hardly enter the irregularities.

The region where only the binder is substantially present on the substrate side surface of the low refractive layer can be calculated by the following operations (I) to (IV).
(I) In order to observe the binder existing between the particles of the low refractive index layer of the transfer sheet and the base material layer with TEM or STEM, the transfer sheet is cut perpendicular to the sheet and sliced with a microtome. The thickness of the flakes is preferably in the range of 50 nm to 200 nm.
<Example of (I)>
First, the sample was cut into 5 mm square pieces and embedded in resin. Next, it trimmed with the glass knife so that a cross section might be obtained. At this time, a microtome (for example, an ultramicrotome manufactured by Leica Microsystems) was used. Next, the trimmed cut surface was extracted as a thin piece having a thickness of about 80 nm using a diamond knife.

(II) The transfer sheet is imaged with a TEM or STEM. The acceleration voltage of TEM or STEM is preferably 30 kV or more, and F.O.V (Field Of View) is preferably 365 nm square to 1825 nm square.
<Example of (II)>
Equipment used: Hitachi High-Technologies scanning electron microscope S-4800 Type I
Acceleration voltage: 30 kV
Observation mode: STEM
Observation magnification: × 200k
F.O.V (Field Of View): 630 nm square

(III) Extract 10 arbitrary particles close to the base material from the observation image, and calculate the linear distance from the point closest to the base material of each particle to the base material.
(IV) The same operation is performed 5 times on the observation image of another screen of the same sample, and the value obtained from the total number of 50 total is substantially only the binder on the substrate side surface of the low refractive layer The area to be used.

The region where only the binder resin is substantially present on the surface of the base material side of the low refractive index layer is preferably 1 nm or more, more preferably 2 nm or more from the surface of the low refractive index layer. From the viewpoint of maintaining antireflection properties, the region is preferably 20 nm or less, and more preferably 15 nm or less.
In addition, the region where only the binder resin is substantially present is a binder on the surface of the low refractive index layer on the substrate side at 500 nm in the width direction of the low refractive index layer of the photograph obtained by photographing the vertical cross section of the transfer sheet with STEM. It shall mean the area where only resin is present.
Further, of the entire surface on the base material side of the low refractive index layer, the region where only the binder resin is substantially present is preferably 60% or more, more preferably 70% or more, and 80% or more. More preferably, it is more preferably 90% or more.

<Adherent>
The material of the adherend to which the transfer layer is transferred is not particularly limited, and examples thereof include glass, ceramics, metal and wood in addition to various plastics. Also, the thickness of the adherend is not particularly limited, and it may be as thin as a micron level or as thick as a plate. Further, the shape of the adherend is not particularly limited, and may be a planar shape or a three-dimensional shape.

[Coating composition]
The coating composition of the present invention is a coating composition for forming a low refractive index layer comprising hollow particles having an average particle size of 60 to 140 nm and a silicone compound as a binder resin component.
The coating composition of the present invention is useful as the above-described coating composition for forming the low refractive index layer of the low refractive member of the present invention or the above-described coating composition for forming the low refractive index layer of the transfer sheet of the present invention. It is.

Embodiments and preferred embodiments of the hollow particles and the binder resin component contained in the coating composition are the hollow particles and the binder resin component contained in the low refractive index layer of the low refractive member of the present invention described above unless otherwise specified. This is the same as the embodiment and the preferred embodiment.

The average particle diameter of the hollow particles of the coating composition can be calculated by the following operations (1) to (3).
(1) In order to observe the hollow particles of the coating composition with a transmission electron microscope (TEM), the coating composition is diluted about 100 times with a main solvent, and this is applied to a collodion membrane applied mesh and dried for a TEM observation sample. Is made.

(2) The material for TEM observation of the coating composition is imaged with a transmission electron microscope (TEM). The accelerating voltage of a transmission electron microscope (TEM) is preferably 100 kv to 200 kV, and the F.O.V (Field Of View) is preferably 365 nm square to 1825 nm square.
<Example of (2)>
Equipment used: Transmission electron microscope manufactured by FEI Tecnai G2 Spirit
Acceleration voltage: 120 kV
Observation mode: TEM
Observation magnification: x30k
F.O.V (Field Of View): 680 nm square

(3) Image analysis is performed from the observed image according to the following procedure.
1. Arbitrary 10 particles are extracted from the observation image, and the particle portion is filled with image analysis software (paint or the like) along the outer diameter of the particle. When the particles are aggregated, the above-described painting operation is performed by dividing the aggregated particles into individual particles instead of considering the aggregated particles as one particle.
2. The area (px ^ 2) of the filled portion is calculated by image analysis software (ImageJ or the like).
3. The equivalent circle diameter (px) is calculated from the area.
4). The length per pixel is calculated from the scale bar of the TEM image.
5. Using the coefficient “4.”, the equivalent circle diameter (px) calculated in “3.” is converted to nm.
6. An average value of 10 equivalent circle diameters is obtained, and the obtained value is defined as “average particle diameter (D)”.

The coating composition preferably contains a solvent.
Examples of the solvent include ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), ethers (dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons (cyclohexane, etc.), Aromatic hydrocarbons (toluene, xylene, etc.), halogenated carbons (dichloromethane, dichloroethane, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), alcohols (butanol, cyclohexanol, etc.), cellosolves ( Examples thereof include methyl cellosolve, ethyl cellosolve, etc.), cellosolve acetates, sulfoxides (dimethyl sulfoxide, etc.), amides (dimethylformamide, dimethylacetamide, etc.), etc., and mixtures thereof may be used.
The content of the solvent in the coating composition is preferably 60 to 95% by mass and more preferably 70 to 90% by mass with respect to the total amount of the coating composition. By making the content of the solvent 60% by mass or more, it is possible to easily improve the workability during coating by suppressing the increase in viscosity of the coating composition, and by controlling the content to 95% by mass or less, drying unevenness is suppressed. It can be done easily.

The coating composition contains a solvent, and when the absolute value of the zeta potential of the hollow particles in the coating composition when 95% by mass or more of the solvent is propylene glycol monomethyl ether acetate is defined as A (mV), It is preferable to satisfy the formula (i).
10.0 mV ≦ A (i)

By setting A (absolute value of zeta potential) to 10.0 mV or more, aggregation of the hollow particles in the coating composition can be suppressed, and whitening of the low refractive index layer formed from the coating composition can be easily suppressed.
In formula (i), A (the absolute value of the zeta potential) is more preferably 12.0 mV or more, further preferably 13.0 mV or more, and further preferably 15.0 mV or more.
In the present specification, the density of the hollow particles means “apparent density”. The apparent density can be measured by the Le Chatelier specific gravity bottle method.

The coating composition is useful as a coating composition for a low refractive index layer having a thickness of 0.5 to 5.0 μm. As described above, in the case of a thick low refractive index layer having a thickness of 0.5 μm or more, aggregated hollow particles are taken into the low refractive index layer. For this reason, it is technically significant that the coating composition satisfies the above formula (i) to easily suppress the aggregation of the hollow particles.

When measuring the zeta potential in the formula (i), 95% by mass or more of the total solvent of the coating composition is propylene glycol monomethyl ether acetate. The proportion of propylene glycol monomethyl ether acetate in the total solvent of the coating composition is preferably 97% by mass or more, more preferably 99% by mass or more, and further preferably 100% by mass.
When the composition contains a solvent other than propylene glycol monomethyl ether acetate in a proportion exceeding 5% by mass, the hollow particles are obtained after replacing the solvent so that 95% by mass or more of the total solvent becomes propylene glycol monomethyl ether acetate. What is necessary is just to measure the zeta potential.
Furthermore, when measuring the zeta potential in the formula (i), the solid content concentration of the coating composition is adjusted to 20 ± 1 mass%.
The absolute value of the zeta potential tends to increase by reducing the difference between the density of the hollow particles (apparent density) and the density of the solvent.

In this specification, the zeta potential of the hollow particles is the average value of 10 measurements. Moreover, in this specification, it shall measure with the electroacoustic method (ESA method). The ESA method can be measured by, for example, “ZetaProbe Analyzer ™” manufactured by Colloidal Dynamics, LLC (Ponte Vedra Beach, Florida, USA).
The ESA method is a method in which an alternating voltage is applied to a colloidal solution and a zeta potential is measured from an ultrasonic ESA signal generated by vibration of particles. The ESA signal is represented by the following formula (ii). The magnitude of the ESA signal correlates with the concentration (φ) of particles with dynamic mobility (μ). Further, the particle size is analyzed from the phase delay of the generated ultrasonic wave due to the difference in the moment of inertia of the particles when an AC voltage is applied, and the obtained particle size is used for the zeta potential analysis. The zeta potential (ζ) reflecting the particle diameter is calculated by measuring at a plurality of frequencies (the following formula (iii)).
The zeta potential value can be negative or positive depending on the polarity of the charge on the particle. The “magnitude” of the zeta potential is expressed as an absolute value (for example, a zeta potential value of −35 mV has a higher magnitude than a zeta potential value of −20 mV). The magnitude of the zeta potential reflects the degree of electrostatic repulsion between identically charged particles in the dispersion. The higher the magnitude of the zeta potential, the more stable the particles in the dispersion.

A: Constant Z: Acoustic impedance (product of sound speed and density)
φ: Particle volume concentration Δρ: Particle-solvent density difference ρ: Solvent density μ: Dynamic mobility

ζ: zeta potential G: function f: frequency a: particle radius

The coating composition may contain additives such as a surfactant, a dispersant, an antistatic agent, an antioxidant, and an ultraviolet absorber.

The coating composition can be formed into a low refractive index layer by, for example, coating on a substrate, prebaking (drying), and further heat curing.
In the pre-baking (drying), the temperature is preferably 60 to 150 ° C., more preferably 80 to 120 ° C., and the time is preferably 40 to 200 seconds, more preferably 50 to 150 seconds.
In thermosetting, the temperature is preferably 150 to 260 ° C., more preferably 170 to 250 ° C., and the time is preferably 5 to 45 minutes, more preferably 15 to 35 minutes.
By setting the drying conditions and thermal curing conditions of the coating composition within the above ranges, rapid drying of the coating composition and / or rapid curing of the binder resin is suppressed, and the surface of the low refractive index layer becomes uneven. This can be easily suppressed.

[Laminate]
The laminate of the present invention comprises a vapor deposition film on the low refractive index layer of the low refractive member of the present invention described above.

The deposited film is silicon (Si), boron (B), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium. Vacuum deposition using one or more of inorganic materials such as (Ti), lead (Pb), zirconium (Zr), yttrium (Y), indium (In), antimony (Sb), these oxides, and these nitrides as raw materials Further, it can be formed by a physical vapor deposition (PVD) method such as sputtering or ion plating, a chemical vapor deposition (CVD) method such as plasma chemical vapor deposition, thermal chemical vapor deposition, or photochemical vapor deposition.
The thickness of the deposited film is usually about 5 to 500 nm.

The surface shape of the low refractive index layer located in the lower layer of the deposited film is preferably less uneven. By reducing the unevenness of the surface shape of the low refractive index layer, it is possible to easily form a deposited film cleanly without unevenness. In order to reduce the unevenness of the surface shape of the low refractive index layer, it is preferable to use a component with little shrinkage as the binder resin of the low refractive index layer or to form the low refractive index layer by transfer.

Moreover, it is preferable that the low refractive index layer located in the lower layer of a vapor deposition film contains the hardened | cured material of the composition containing the silicone type compound which has an alkoxy group as a hardened | cured material of the composition containing a silicone type compound. By setting it as the said structure, it can be made easy to make favorable the adhesiveness of a low-refractive-index layer and a vapor deposition film.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. In addition, this invention is not limited to the form as described in an Example.

1. Evaluation and Measurement The following measurements and evaluations were performed on the low refractive members obtained in Examples and Comparative Examples. The results are shown in Table 1. Note that the sizes of the low-refractive members and samples used in the following measurements and evaluations are examples, and are not limited to these. For example, in the measurement of scratch resistance described in 1-1 below, a low-refractive member having a 10 cm square is used, but the size may be made smaller than this.
The atmosphere during each measurement and evaluation was a temperature of 23 ° C. ± 5 ° C. and a humidity of 40 to 65%. Further, before the start of each measurement and evaluation, the sample prepared from the low refractive member, the low refractive member or the coating composition for forming a low refractive index layer was exposed to the atmosphere for 30 minutes or more.

1-1. Using a low refractive member of scratch resistance 10cm square, place the surface of the low refractive index layer, pressing a steel wool # 0000, after rubbing back and forth 10 times under a load 50 g / cm ^2, a black plate on the back surface of the sample The antireflection property was visually evaluated under the illumination of a fluorescent lamp. “A” indicates that the anti-reflective property between the rubbing site and the non-rubbed site cannot be distinguished, and “C” indicates that the anti-reflective property between the rubbing site and the non-rubbed site can be distinguished.

1-2. Crack A 10 cm square low-refractive member was used, a black plate was placed on the back of the low-refractive member, and whether or not a crack occurred in the low-refractive index layer was visually evaluated under illumination of a fluorescent lamp. “A” indicates that no crack was confirmed, and “C” indicates that a fine crack was confirmed.

1-3. The refractive index of the low-refractive index layer was calculated using a low-refractive-index member having a refractive index of 10 cm square, using a microspectrophotometer (trade name “OPTM-A1” manufactured by Otsuka Electronics Co., Ltd.). Those having a refractive index of 1.30 or less have good antireflection properties and are acceptable.

1-4. Low Refractive Index Layer Thickness Using a 10 cm square low refractive member, the thickness (μm) of the low refractive index layer was calculated by a microspectrophotometer (Otsuka Electronics Co., Ltd., trade name “OPTM-A1”). After confirming that there was no defect, the thickness at 10 locations was measured, and the average value at 10 locations was taken as the thickness of the low refractive index layer of each Example and Comparative Example.

1-5. Adhesiveness Using a 10 cm square low refractive member, the adhesive strength between the substrate (glass) and the low refractive index layer was evaluated by an adhesion test by the cross-cut method of JIS K5600-5-6: 1999. The adhesive force classification numbers are shown in Table 1. There are six types of classification numbers 0 to 5 below.
<Classification number>
0: The edge of the cut is completely smooth and there is no peeling to the eyes of any lattice.
1: Small peeling of the coating film at the intersection of cuts. It is clearly not more than 5% that the crosscut is affected.
2: The coating film is peeled along the edge of the cut and / or at the intersection. The cross-cut part is clearly affected by more than 5% but not more than 15%.
3: The coating film is partially or completely peeled along the edge of the cut, and / or various parts of the eye are partially or completely peeled off. The cross-cut portion is clearly affected by more than 15% but not more than 35%.
4: The coating film is partially or completely peeled along the edge of the cut, and / or some eyes are partially or completely peeled off. The cross-cut portion is clearly not affected by more than 65%.
5: Any of the degree of peeling that cannot be classified even with classification 4.

1-6. Haze The haze (%) of the low refractive member was measured according to JIS K7136: 2000. The light incident surface was the substrate side. Using 10 cm square low-refractive members, 10 locations were selected randomly from locations without scratches or defects in the sample, and the arithmetic average value of 10 locations was defined as the haze (%) of the low-refractive members of each Example and Comparative Example. .

1-7. Total light transmittance The total light transmittance (%) of the low refractive member was measured according to JIS K7361-1: 1997. The light incident surface was the substrate side. A 10 cm square low refractive member is used, and 10 points are selected at random from places where there are no scratches or defects on the sample, and the arithmetic average value of 10 points is calculated as the total light transmittance (%) of the low refractive member of each example and comparative example. ).

1-8. Diffuse light reflectance R _SCE
The release film of the trade name “Kikkiri Mieru” manufactured by Yodogawa Seisakusho is peeled off, and the exposed black pressure-sensitive adhesive layer is bonded to the surface of the glass substrate side of the 10 cm square low-refractive member of Examples and Comparative Examples. A sample in which a black pressure-sensitive adhesive layer (total light transmittance of 1% or less) and a plastic film were laminated on the surface of the glass substrate was prepared.
Integrating sphere spectrophotometer (Konica Minolta Co., Ltd., trade name: CM-2600d) used, measured from the surface of the low refractive index layer side of the sample, diffuse light reflectance of the sample _(R SCE) (%) did. Ten locations were selected at random from locations having no scratches or defects on the sample, and the arithmetic average value at the 10 locations was defined as the diffused light reflectance R _SCE (%) of the low refractive member of each Example and Comparative Example.
The light source of the integrating sphere spectrophotometer is D65, the position of the light receiver is +8 degrees with respect to the normal line of the sample, the position of the light trap is −8 degrees with respect to the normal line of the sample, and the viewing angle is Twice.

1-9. Zeta potential The zeta potential was measured using a ZetaProbe Analyzer ™ from Colloidal Dynamics, LLC (Ponte Vedra Beach, Florida, USA) under the following conditions. Table 1 shows the absolute value (mV) of the obtained zeta potential. In addition, the density (apparent density) of the hollow particles in Examples and Examples was measured by the Le Chatelier specific gravity bottle method.
<Preparation of calibration and measurement samples>
First, calibration was performed using KSiW calibration solution (0.5 mS / cm) supplied from Colloidal Dynamics. Next, 30 g of a sample (the coating composition for forming a low refractive index layer of Examples and Comparative Examples) was placed in a 30 mL Teflon cup equipped with a stirring rod and sufficiently stirred at a stirring speed of 250 rpm. A sample for measuring potential was used.
<Measurement and analysis conditions>
The zeta potential was measured at a sample temperature (about 20 ± 2 ° C.) using a dipping probe and a 10-point test in a one-point mode. The data was analyzed using ZP version 2.14c Polar ™ software provided by Colloidal Dynamics.

2. Production of low refractive member [Example 1]
On a 10 cm square, 0.7 mm thick glass substrate (non-alkali glass manufactured by Corning, trade name “EAGLE XG”), a coating composition for forming a low refractive index layer having the following formulation is applied by a spin coater (MS-B150 ( Micasa Co., Ltd.) and pre-baked (dried) for 120 seconds at 100 ° C. to obtain a coated film, which was heated in an oven at 200 ° C. for 20 minutes to prepare a composition containing a silicone compound. Curing was performed to form a low-refractive index layer having a thickness of 1.0 μm to obtain a low-refractive member of Example 1. When the glass substrate was measured according to JIS K7136: 2000, a haze of 0 was obtained. The diffuse light reflectivity ( _RSCE ) was 0.04%.
<Coating composition for forming low refractive index layer>
Hollow particles: 20 parts by mass (hollow silica particles having an average particle diameter of 75 nm formed by surface treatment with a silane coupling agent having a methacryloyl group)
Binder resin component: 10 parts by mass (a substituted hydrocarbon group having an epoxy group as a substituent, and an oligomer type silicone compound in which an alkoxy group is directly bonded to a silicon atom, epoxy equivalent: 350 g / mol, alkoxy group amount: 42 (% By mass, product number “X-41-1059A” manufactured by Shin-Etsu Chemical Co., Ltd., active ingredient 100%)
Surfactant: 0.21 part by mass (trade name “F-554” manufactured by DIC, 100% active ingredient)
Propylene glycol monomethyl ether acetate: 120 parts

[Example 2]
A low refractive member of Example 2 was obtained in the same manner as Example 1 except that the thickness of the low refractive index layer was changed to 3.0 μm.

[Example 3]
A low refractive member of Example 3 was obtained in the same manner as in Example 1 except that the content of the hollow particles in the coating composition for forming a low refractive index layer was changed to 10 parts by mass.

[Example 4]
Except for changing the hollow particles of the coating composition for forming a low refractive index layer to hollow silica particles having an average particle diameter of 60 nm obtained by surface treatment with a silane coupling agent having a methacryloyl group, in the same manner as in Example 1, A low refractive member of Example 4 was obtained.

[Example 5]
Except for changing the hollow particles of the coating composition for forming a low refractive index layer to hollow silica particles having an average particle diameter of 100 nm obtained by surface treatment with a silane coupling agent having a methacryloyl group, in the same manner as in Example 1, A low refractive member of Example 5 was obtained.

[Comparative Example 1]
A low refractive index member of Comparative Example 1 was obtained in the same manner as in Example 1 except that the thickness of the low refractive index layer was changed to 0.2 μm.

[Comparative Example 2]
A low refractive member of Comparative Example 2 was obtained in the same manner as in Example 1 except that the thickness of the low refractive index layer was changed to 5.5 μm.

[Comparative Example 3]
Except for changing the hollow particles of the coating composition for forming a low refractive index layer to hollow silica particles having an average particle diameter of 50 nm obtained by surface treatment with a silane coupling agent having a methacryloyl group, in the same manner as in Example 1, The low refractive member of Comparative Example 3 was obtained.

[Comparative Example 4]
Except for changing the hollow particles of the coating composition for forming a low refractive index layer to hollow silica particles having an average particle diameter of 150 nm obtained by surface treatment with a silane coupling agent having a methacryloyl group, in the same manner as in Example 1, The low refractive member of Comparative Example 4 was obtained.

[Comparative Example 5]
Except for changing the binder resin component of the coating composition for forming a low refractive index layer to a non-silicone epoxy resin (product number “EHPE3150” manufactured by Daicel Corporation, solid content: 100%), the same as in Example 1, A low refractive member of Comparative Example 5 was obtained.

[Comparative Example 6]
The hollow particles of the coating composition for forming a low refractive index layer are changed to hollow silica particles having an average particle diameter of 50 nm obtained by surface treatment with a silane coupling agent having a methacryloyl group, and further the coating composition for forming a low refractive index layer A low refractive member of Comparative Example 6 was obtained in the same manner as in Example 1 except that the content of the hollow particles of the product was changed to 40 parts by mass.

As apparent from the results in Table 1, the low refractive member of Examples 1-5, despite the thickness of the low refractive index layer is thick, haze and R _SCE is small, whitening is suppressed good visibility It can be confirmed that In addition, it can be confirmed that the low refractive members of Examples 1 to 5 can suppress cracks because the low refractive index layer is not too thick. In addition, it can be confirmed that the low refractive members of Examples 1 to 5 have a refractive index of the low refractive index layer of 1.30 or less, suppress surface reflection, and have antireflection properties. Furthermore, it can be confirmed that the low refractive members of Examples 1 to 5 cannot be distinguished in the antireflection property between the scratched portion and the non-rubbed portion, and are excellent in the antireflection performance after scratching.

3. Preparation of transfer sheet [Example 6]
As a release sheet, an A4 size polyimide film having a thickness of 50 μm was prepared. A low refractive index layer having a thickness of 1.0 μm was formed on one surface of the polyimide film in the same manner as in Example 1.
Next, a hard coat layer is formed on the low refractive index layer by coating, drying, and irradiating with ultraviolet rays (irradiation amount 50 mJ / cm ² ) so that the thickness after drying the following hard coat coating solution becomes 5 μm. did. Next, an anchor coat layer was formed on the hard coat layer by applying and drying the following coating solution for anchor coat layer so that the thickness after drying was 2 μm. Next, on the anchor coat layer, the following adhesive layer coating solution was applied and dried so that the thickness after drying was 2 μm to form a heat-sensitive adhesive layer. Transfer of Example 6 A sheet was obtained.

<Coating liquid for hard coat layer>
Composition containing ultraviolet curable acrylic acrylate, silica particles and photopolymerization initiator (DNP Fine Chemical Co., Ltd., trade name: KYK coating agent (82L)): 100 parts by mass. Hexanemethylene diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., Product name: Coronate 2203): 2 parts by mass / diluent solvent (methyl ethyl ketone, methyl isobutyl ketone): appropriate amount

<Coating solution for anchor coat layer>
・ Acrylic polyol (manufactured by Taisei Fine Chemical Co., Ltd., trade name: ACRYT 6RH084T): 100 parts by mass : Appropriate amount

<Coating liquid for adhesive layer>
・ Vinyl chloride vinyl acetate copolymer (trade name “ST-P A Varnish”, manufactured by DNP Fine Chemical Co., Ltd., 30% solids): 100 parts by mass ・ Diluting solvent (methyl ethyl ketone, toluene): appropriate amount

4). Transfer of resin layer to adherend As a adherend, a 10 cm square, 2.0 mm thick transparent acrylic plate (manufactured by Kuraray Co., Ltd., trade name “Paragrass P001 Clear”) was prepared.
The transfer sheet of Example 6 is cut to about 15 cm square so that the heat-sensitive adhesive layer side faces the adherend side on the adherend so that the entire surface of the transparent acrylic plate is covered. After placing and fixing one piece on the roll transfer start side of the transfer sheet with tape, using a roll-type hot stamping machine (trade name “RH-300” manufactured by Navitas), the roll temperature is 220 to 240 ° C., The adherend and the transfer layer were brought into close contact with each other under a roll speed of 20 mm / s. Next, the release sheet (polyimide film) was peeled off to form a transfer layer on the adherend.
Subsequently, ultraviolet rays were irradiated (irradiation amount 800 mJ / cm ² ) to accelerate the curing of the hard coat layer to obtain a low refractive member.

The low refractive member obtained using the transfer sheet of Example 6 was suppressed in whiteness and had good visibility despite the large thickness of the low refractive index layer. Moreover, the low refractive member obtained using the transfer sheet of Example 6 was able to suppress cracks because the low refractive index layer was not too thick. In addition, the low refractive member obtained using the transfer sheet of Example 6 was a material having a sufficient antireflection property because surface reflection was suppressed. Further, the low refractive member obtained by using the transfer sheet of Example 6 had a soft adhesive layer between the adherend (transparent acrylic plate) and the low refractive index layer. It was excellent in scratch resistance to such an extent that the antireflection property from the non-rubbed portion could not be distinguished.

Claims

A low refractive index member having a low refractive index layer on a substrate, wherein the low refractive index layer has a thickness of 0.5 to 5.0 μm, and includes hollow particles and a binder resin. A low refractive member having an average particle diameter of 60 to 140 nm and containing a cured product of a composition containing a silicone compound as the binder resin.
The low refractive member according to claim 1, comprising 100 to 300 parts by mass of the hollow particles with respect to 100 parts by mass of the binder resin.
The low-refractive member according to claim 1 or 2, wherein the silicone compound is formed by directly connecting a substituted hydrocarbon group having a reactive functional group as a substituent to a silicon atom.
The diffusion light reflectance R SCE measured from the low refractive index layer side of the low refractive member is not more than 1.5%, the low refractive member according to any one of claims 1-3.
The low refractive member according to any one of claims 1 to 4, wherein the haze according to JISK7136: 2000 is 1.0% or less.
The low refractive index member according to any one of claims 1 to 5, wherein a refractive index of the low refractive index layer is 1.30 or less.
A transfer sheet having a transfer layer on a substrate, wherein the substrate side of the transfer layer is a low refractive index layer, and the low refractive index layer has a thickness of 0.5 to 5.0 μm; and A transfer sheet comprising hollow particles and a binder resin, the hollow particles having an average particle diameter of 60 to 140 nm, and containing a cured product of a composition containing a silicone compound as the binder resin.
A coating composition for forming a low refractive index layer, comprising hollow particles having an average particle diameter of 60 to 140 nm and a silicone compound as a binder resin component.
When the absolute value of the zeta potential of the hollow particles in the coating composition when the coating composition contains a solvent and 95% by mass or more of the solvent is propylene glycol monomethyl ether acetate is defined as A (mV) The coating composition according to claim 8, which satisfies the following formula (i):
10.0 mV ≦ A (i)
A laminate comprising a deposited film on the low refractive index layer of the low refractive member according to any one of claims 1 to 6.